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<strong>Cardiovascular</strong><br />

<strong>Research</strong> <strong>Day</strong><br />

ABSTRACT BOOK<br />

November 3, <strong>2017</strong><br />

Lexington Convention Center<br />

HealthCare ®<br />

GILL HEART INSTITUTE<br />

Saha <strong>Cardiovascular</strong><br />

<strong>Research</strong> Center


TABLE OF CONTENTS<br />

Schedule for the <strong>Day</strong> ............................................................................................................................. 2<br />

<strong>2017</strong> Gill Heart Institute Young Investigator Award ................................................................. 6<br />

<strong>2017</strong> Distinguished Alumni Speaker .............................................................................................. 7<br />

Featured Speakers ................................................................................................................................. 8<br />

Event Supporters ................................................................................................................................. 11<br />

Poster Judges ........................................................................................................................................ 13<br />

Poster Participants ............................................................................................................................. 14<br />

<strong>Abstract</strong>s ................................................................................................................................................ 16<br />

Survey ................................................................................................................................................... 121<br />

1


SCHEDULE FOR THE DAY<br />

Friday, November 3<br />

University of Kentucky <strong>Cardiovascular</strong> <strong>Research</strong> <strong>Day</strong><br />

Lexington Convention Center | Bluegrass Ballrooms<br />

8:15 am<br />

Guest Check –In Begins | Continental Breakfast | Bluegrass Prefunction<br />

8:30 am<br />

Career Development Session for Trainees | Continental Breakfast | Thoroughbred<br />

Room 8<br />

9:30 am<br />

Scientific Session I | Bluegrass Ballroom I<br />

Chair: Gregory Graf, Ph.D. and Gia Mudd-Martin, Ph.D., MPH, R.N.<br />

9:30 am<br />

Alan Daugherty, Ph.D., D.Sc., Director, Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center<br />

Welcoming Comments<br />

9:35 am<br />

Trainee Presentations<br />

Ahmed Al-Darraji | Ahmed Abdel-Latif Lab | University of Kentucky<br />

Azithromycin Therapy Reduces Cardiac Inflammation and Mitigates<br />

Adverse Cardiac Remodeling after Myocardial Infarction: Potential<br />

Therapeutic Targets<br />

Kelsey Conrad | Phil Owens Lab | University of Cincinnati<br />

Increased Circulating Trimethylamine N-oxide (TMAO) Augments the<br />

Incidence of Abdominal Aortic Aneurysm in Low Penetrant C57BL/6J<br />

Mice<br />

Ryan Allen, Ph.D. | Kasey Vickers Lab | Vanderbilt University<br />

Circulating Bacterial Small RNA Bound to LDL Induce Inflammatory<br />

Activation of Macrophages<br />

2


10:35 am<br />

<strong>Research</strong> Blitz I<br />

David Henson | University of Kentucky<br />

Mohamed AboAly, MD | University of Kentucky<br />

Zheying “Jeff” Chen | University of Kentucky<br />

Dylan Colli | University of Kentucky<br />

Allison Cooke | University of Cincinnati<br />

Mihir Shah | University of Kentucky<br />

Jiansheng Huang, PhD | Vanderbilt University<br />

Aida Javidan, MS | University of Kentucky<br />

Michael Petriello, PhD | University of Kentucky<br />

Michael Kuefner | University of Tennessee Health Science Center<br />

Robin Shoemaker | University of Kentucky<br />

10:45 am<br />

Featured Speaker<br />

Calum MacRae, M.D., Ph.D. | Harvard Medical School<br />

Bridging the Gaps in <strong>Cardiovascular</strong> Translation<br />

11:30 am<br />

Lunch | Scientific Session II | Bluegrass Prefunction<br />

12:00 pm<br />

Welcoming Remarks<br />

Mark Newman, M.D. | University of Kentucky Executive Vice<br />

President for Health Affairs<br />

12:15 pm<br />

Distinguished Alumni Presentation<br />

John Charles, Ph.D. | NASA Human <strong>Research</strong> Program at Johnson<br />

Space Center<br />

From the Bluegrass to Beyond the Blue<br />

1:00 pm<br />

Poster Session | Bluegrass Ballroom II<br />

1:00 pm<br />

Odd Numbered Posters<br />

2:00 pm<br />

Even Numbered Posters<br />

3


SCHEDULE FOR THE DAY continued<br />

Friday, November 3<br />

University of Kentucky <strong>Cardiovascular</strong> <strong>Research</strong> <strong>Day</strong><br />

Lexington Convention Center | Bluegrass Ballrooms<br />

3:00 pm<br />

Scientific Session III | Bluegrass Ballroom I<br />

Chair: Lisa Cassis, Ph.D. and Dan Rader, M.D.<br />

3:00 pm<br />

Trainee Presentations<br />

Brooke Ahern | Jon Satin Lab | University of Kentucky<br />

Cardiac Specific Rad Deletion Enhances Cardiac Function through Safe,<br />

Stable Positive Inotropic Support<br />

Ibra Fancher, Ph.D. | Irena Levitan Lab | University of Illinois at<br />

Chicago<br />

Hypercholesterolemia-induced endothelial dysfunction is rescued by<br />

overexpression of endothelial Kir2.1 in resistance arteries<br />

3:30 pm<br />

<strong>Research</strong> Blitz II<br />

Shayan Mohammadmoradi, MS | University of Kentucky<br />

Feiming Ye | University of Kentucky<br />

Chia-Hua Wu | University of Kentucky<br />

Hannah Russell | University of Cincinnati<br />

Katelyn Ahern | University of Virginia<br />

Hisashi Sawada, MD, PhD | University of Kentucky<br />

Courtney Turpin, MS | University of Kentucky<br />

Zhihong Yang, PhD | National Institutes of Health<br />

Miao Liu, PhD | University of Kentucky<br />

Bradley Wright | University of Kentucky<br />

4


3:40 pm<br />

Featured Speaker<br />

Steven Houser, Ph.D. | Temple University<br />

Cardiac Repair and Injury<br />

4:25 pm<br />

Gill Heart Institute Translational Early Career Award Recipient<br />

Kiran Musunuru, M.D., Ph.D., MPH | University of Pennsylvania<br />

Discovery and Therapeutic Genome Editing of <strong>Cardiovascular</strong> Disease<br />

Genes<br />

5:15 pm<br />

Networking Reception | Bluegrass Prefunction<br />

6:00 pm<br />

Dinner and Awards Ceremony | Bluegrass Prefunction<br />

Special Presentation from Mark Stoops |University of Kentucky Head Football Coach<br />

5


<strong>2017</strong> GILL HEART INSTITUTE<br />

YOUNG INVESTIGATOR AWARD<br />

Kiran Musunuru, M.D., Ph.D., MPH<br />

Associate Professor<br />

<strong>Cardiovascular</strong> Medicine and Genetics<br />

Perelman School of Medicine<br />

University of Pennsylvania<br />

Dr. Musunuru received his medical degree from Weill<br />

Cornell Medical College, his Ph.D. from The Rockefeller<br />

University, and his Masters of Public Health from Johns<br />

Hopkins Bloomberg School of Public Health. He trained in<br />

Internal Medicine at Brigham and Women's Hospital and<br />

<strong>Cardiovascular</strong> Medicine at Johns Hopkins Hospital,<br />

followed by postdoctoral work at Massachusetts General<br />

Hospital and the Broad Institute of MIT and Harvard.<br />

Dr. Musunuru's research focuses on the genetics of cardiovascular and metabolic diseases<br />

and seeks to identify naturally occurring genetic variants that predispose to or protect<br />

against disease and can be used to develop therapies to protect the entire population. In<br />

2016, he received the Presidential Early Career Award for Scientists and Engineers from<br />

the White House, as well as the American Heart Association's Award for Meritorious<br />

Achievement.<br />

6


<strong>2017</strong> DISTINGUISHED ALUMNI<br />

SPEAKER<br />

John Charles, Ph.D.<br />

Chief Scientist, NASA Human <strong>Research</strong> Program at Johnson<br />

Space Center<br />

John B. Charles, Ph.D., is the Chief Scientist of NASA’s<br />

Human <strong>Research</strong> Program (HRP), responsible for the<br />

scientific direction of human research and technology<br />

development enabling astronauts to go beyond low Earth<br />

orbit and eventually to Mars. Previously he was HRP’s<br />

Associate Manager for International Science and led NASA’s<br />

space life sciences planning for the joint US/Russian oneyear<br />

mission on ISS and the Twins Study.<br />

Dr. Charles earned his B.S. in biophysics at The Ohio State<br />

University and his doctorate in physiology and biophysics at the University of Kentucky.<br />

He came to the Johnson Space Center in 1983 a postdoctoral fellow and became a civil<br />

servant in 1985. He is co-developer of the Shuttle-era fluid-loading countermeasure, and<br />

investigated the cardiovascular effects of space flight using ultrasound, re-entry data<br />

recording and in-flight lower body negative pressure on Space Shuttle astronauts and on<br />

crewmembers of the Russian space station Mir. He coordinated all of the NASA-sponsored<br />

biomedical, biological and microgravity science investigations as Mission Scientist for<br />

American astronaut missions on Mir, on STS-95, John Glenn’s Shuttle flight, and on STS-<br />

107, Columbia’s last mission in January 2003.<br />

He is a Fellow of the Aerospace Medical Association and has been a member since 1983. He<br />

is also a Full Member of the International Academy of Astronautics (IAA) and co-chaired<br />

the 18 th IAA “Humans in Space Symposium” in Houston in 2011.<br />

He has published 75 scientific papers and space history articles and has received several<br />

professional awards, including National Space Club and Foundation Eagle Manned Mission<br />

Award (<strong>2017</strong>), the NASA Exceptional Achievement Medal (2014), the ASMA “Joe Kerwin<br />

Award” (2011), the “Hubertus Strughold Award” of the Space Medicine Association (2001)<br />

and the NASA Exceptional Service Medal (2000).<br />

7


FEATURED SPEAKER<br />

Calum MacRae, M.D., Ph.D.<br />

Chief, <strong>Cardiovascular</strong> Medicine, Brigham and Women’s Hospital<br />

Associate Professor of Medicine, Harvard Medical School<br />

Calum MacRae is a cardiologist, geneticist and developmental<br />

biologist who trained in Edinburgh, London and Boston. He is<br />

Chief of <strong>Cardiovascular</strong> Medicine at Brigham and Women’s<br />

Hospital and Associate Professor of Medicine at Harvard Medical<br />

School. He is also an Associate Member at the Broad Institute<br />

and a Principal Faculty Member at the Harvard Stem Cell<br />

Institute. His research is focused on understanding the<br />

fundamental mechanisms of disease using human studies and<br />

complementary efforts combining systems level modeling with empiric high-throughput<br />

biology in the zebrafish. His lab uses automated screens in fish to define the genetic<br />

architecture of disease and to explore gene-drug (or environment) interactions through the<br />

interrogation of large-scale chemical libraries. His interests include heart failure,<br />

arrhythmias and coronary disease, genomic medicine, innovation in phenotyping and the<br />

redesign of clinical care.<br />

8


FEATURED SPEAKER<br />

Steve Houser, Ph.D., FAHA<br />

Senior Associate Dean, <strong>Research</strong><br />

Vera J. Goodfriend Endowed Chair, <strong>Cardiovascular</strong> <strong>Research</strong><br />

Chair and Professor, Physiology<br />

Director, <strong>Cardiovascular</strong> <strong>Research</strong> Center<br />

Professor, Medicine<br />

For forty years, Steven R. Houser, Ph.D. , FAHA has been a<br />

constant presence at the Lewis Katz School of Medicine at<br />

Temple University. A committed alumnus, beloved<br />

instructor, scientific-leader and an internationallyrecognized<br />

expert in cardiac biology and pathophysiology,<br />

A widely respected and prolific cardiovascular researcher,<br />

Dr. Houser first came to Temple as a Ph.D. student in physiology before earning a research<br />

fellowship in Cardiology at the School of Medicine. In 1979 he joined the faculty full time,<br />

was named director of the <strong>Cardiovascular</strong> <strong>Research</strong> Center in 2003, chair of the<br />

Department of Physiology in 2006 and Senior Associate Dean of <strong>Research</strong> in 2013 (having<br />

previously held the position from 2003-2007). In 2015 he was appointed to the Vera J.<br />

Goodfriend Endowed Chair in <strong>Cardiovascular</strong> <strong>Research</strong>.<br />

Outside of his Temple appointments, Dr. Houser has recently served as President of the<br />

American Heart Association. During Houser’s long association with the AHA, he has also<br />

served as a fellow, board member, chair of the research committee and president of the<br />

southeastern Pennsylvania affiliate. He has also worked on a number of national AHA<br />

committees.<br />

His research group has helped define many fundamental features of the normal cardiac<br />

myocyte (a muscle cell) and identified defective molecular and cellular processes that<br />

produce abnormal cardiac myocyte function in cardiovascular disease. In 2012, the group<br />

was awarded a five-year $11.6 million grant from the National Heart, Lung, and Blood<br />

Institute of the National Institutes of Health (NIH) to develop new approaches to prevent,<br />

slow or reverse damage to the heart after a heart attack. He is a much sought-after expert<br />

in his field, having been an invited speaker at conferences and symposiums more than 200<br />

times, a reviewer or editor for 13 peer-review journals, served as the chair or member of<br />

numerous NIH study sections and has published more than 210 manuscripts, papers or<br />

book chapters.<br />

9


SPECIAL PRESENTATION<br />

Mark Stoops<br />

Head Coach, University of Kentucky Football<br />

Mark Stoops is in the middle of his fifth year as the University of<br />

Kentucky head football coach. In his first season, Coach Stoops<br />

inherited a program that came off a 2-10 season, averaging 22.1<br />

points per loss. It took just four seasons to return the program to<br />

bowl eligibility and restore a winning culture. In addition to<br />

shaping the Wildcats’ performance on the field, Stoops has been<br />

instrumental in shaping the program off the field. Coach Stoops<br />

assisted in planning and fundraising for the $125 million<br />

renovation of Kroger Field, as well as the new $45 million football complex. These<br />

renovations and the winning culture Coach Stoops brought with him to Lexington have led<br />

to multiple top-25 recruiting classes and optimism for the future of this program.<br />

Coach Stoops grew up surrounded by a football family and is native of Youngstown, Ohio,<br />

one of the nation’s biggest football towns. After high school, he went on to play for Hall of<br />

Fame coach Hayden Fry at the University of Iowa, playing in four bowl games and winning<br />

25 games in three years. After graduation, Coach Stoops spent two seasons as a graduate<br />

assistant coach under Coach Fry. After the ’91 season, he spent four years coaching high<br />

school football before entering the collegiate ranks. Coach Stoops made stops at several<br />

major programs including Iowa, USF, Wyoming, Houston, Arizona, Miami and Florida State.<br />

Fast forward to <strong>2017</strong>, and Coach Mark Stoops is in his 28th season of coaching. He has<br />

compiled a 4-1 career BCS bowl record, won a BCS National Championship, and has<br />

developed 11 NFL 1st round draft picks.<br />

10


EVENT SUPPORTS<br />

Gill Foundation of Texas<br />

●<br />

The Saha Fund for <strong>Cardiovascular</strong> <strong>Research</strong><br />

and Education<br />

●<br />

The Estate and Family of Mrs. Hager Koostra<br />

●<br />

Mr. and Mrs. Bob Allen<br />

11


NOTES<br />

12


<strong>2017</strong> POSTER JUDGES<br />

Douglas Andres<br />

Jason Brandon<br />

J. Mark Brown<br />

William Brown<br />

Lisa Cassis<br />

John Charles<br />

Cherry Croft<br />

Alan Daugherty<br />

Brian Delisle<br />

Sanda Despa<br />

Joyce Evans<br />

Ming Gong<br />

Gregory Graf<br />

Kathryn Gunn<br />

Zhenheng Guo<br />

Rebecca Haeusler<br />

Steven Houser<br />

Wendy Katz<br />

Kevin Pearson<br />

Joe Layne<br />

Sangderk Lee<br />

Norbert Leitinger<br />

Irena Levitan<br />

Zhenyu Li<br />

Xiangan Li<br />

MacRae Linton<br />

Robert Lodder<br />

Analia Loria<br />

Hong Lu<br />

Calum MacRae<br />

Andrew Morris<br />

Kiran Musunuru<br />

Saskia Neher<br />

Fredrick Onono<br />

Phillip Owens<br />

Sabire Ozcan<br />

Romeo Papazyan<br />

Edwards Park<br />

Julie Pendergast<br />

Jonathan Satin<br />

Travis Sexton<br />

Mary Sheppard<br />

Sony Soman<br />

Venkateswaran Subramanian<br />

Lisa Tannock<br />

Elizabeth Tarling<br />

Ryan Temel<br />

Joel Thompson<br />

Jenelle Timmins-Persley<br />

Michael Tranter<br />

Vincent Venditto<br />

Kasey Vickers<br />

Nancy Webb<br />

Wally Whiteheart<br />

Jeremy Wood<br />

Changcheng Zhou<br />

Lin Zhu<br />

Zhihui Zhu<br />

Lin Zhu<br />

Zhihui Zhu<br />

13


<strong>2017</strong> POSTER PARTICIPANTS<br />

40 Mohamed AboAly<br />

11 Brooke Ahern<br />

85 Katelyn Ahern<br />

8 Ahmed Al-Darraji<br />

74 Ryan Allen<br />

67 Yasir Alsiraj<br />

86 Sarah Anthony<br />

26 Kavya Balaji<br />

49 Meenakshi Banerjee<br />

89 Nicolas Barbera<br />

32 Jazmyne Barney<br />

45 Esias Bedingar<br />

12 Dibyajyoti Biswal<br />

88 Yedida Bogachkov<br />

94 Lei Cai<br />

17 Zheying Chen<br />

13 Dylan Colli<br />

72 Kelsey Conrad<br />

73 Allison Cooke<br />

55 Robert Correll<br />

66 Marcielle de Beer<br />

43 Mohamed El-Helw<br />

56 Eman Elsawalhy<br />

70 Ibra Fancher<br />

44 Demetria Fischesser<br />

63 Christy Gliniak<br />

78 Aspen Gutgsell<br />

35 Allison Hall<br />

1 Dwight Harris<br />

15 Peter Hecker<br />

97 David Henson<br />

10 Joseph Herald<br />

31 Jessie Hoffman<br />

38 Amanda Hoskins<br />

41 Tianfei Hou<br />

81 Jiansheng Huang<br />

75 Aida Javidan<br />

80 Ailing Ji<br />

82 Shannon Jones<br />

57 Smita Joshi<br />

54 Tara Keenan<br />

30 Peter Kekenes-Huskey<br />

50 Morgan Kelly<br />

96 Seonwook Kim<br />

77 Alison Kohan<br />

61 Michael Kuefner<br />

92 Lindsey Lanzillotta<br />

18 Bryana Levitan<br />

53 Zhenyu Li<br />

90 Yanzhang Li<br />

93 Tong Li<br />

7 Miao Liu<br />

34 Shu Liu<br />

33 Guogen Mao<br />

51 Eric McGann<br />

46 Gregory Milburn<br />

84 Shayan Mohammadmoradi<br />

9 Mohammad Javad Mollakazemi<br />

60 Kathryn Moore<br />

4 Chase Neumann<br />

5 Laura Peterson<br />

79 Michael Petriello<br />

22 Joshua Preston<br />

20 Seema Rao<br />

62 Benjamin Roberts<br />

71 Hannah Russell<br />

21 Keegan Sammons<br />

39 Kaitlyn Samuels<br />

27 Hisashi Sawada<br />

76 Leslie Sedgeman<br />

48 Travis Sexton<br />

14 Mihir Shah<br />

68 Robin Shoemaker<br />

6 Preetha Shridas<br />

3 Tara Shrout<br />

65 Daniel Silver<br />

87 Loren Smith<br />

91 Wenliang Song<br />

14


83 Stefanka Spassieva<br />

47 Cody Sutphin<br />

37 Joel Thompson<br />

36 Himi Tripathi<br />

64 Courtney Turpin<br />

99 Clint Upchurch<br />

24 Patrick Van Hoose<br />

103 Sahar VarnoosfaderanI<br />

59 Arielle Waller<br />

25 Fang Wang<br />

52 Robert Wendroth<br />

98 Carrie Wiese<br />

29 Patricia Wilson<br />

58 Cassandra Woolley<br />

28 Bradley Wright<br />

19 Congqing Wu<br />

23 Chia-Hua Wu<br />

42 Liping Yang<br />

69 Zhihong Yang<br />

95 Lihua Yang<br />

2 Feiming Ye<br />

16 Xiang Ye<br />

102 Jinchao Zhang<br />

100 Lin Zhu<br />

101 Wanying Zhu<br />

15


<strong>2017</strong> ABSTRACTS<br />

16


1<br />

Extracorporeal Membrane Oxygenation as a Rescue Measure in Patients Experiencing<br />

Respiratory Distress After Non-cardiac Thoracic Surgery<br />

Dwight Harris 1 • Sibu Saha, MD 2<br />

1College of Medicine, University of Kentucky • 2 Cardiothoracic Surgery, University of Kentucky<br />

Medical Student<br />

Extracorporeal Membrane Oxygenation (ECMO) is a rescue measure used to treat patients in every<br />

age group from neonates to adults. ECMO is used to treat many different conditions including<br />

respiratory distress, cardiogenic shock, and trauma. In these patient groups ECMO has been<br />

extensively studied. Recently, physicians have begun using ECMO as a rescue measure in patients<br />

experiencing acute respiratory distress syndrome (ARDS) after non-cardiac thoracic surgery.<br />

Studies on the use of ECMO after non-cardiac thoracic surgery are lacking with only a hand full of<br />

reports published. The goal of this report is to present our experience with patients experiencing<br />

ARDS after non-cardiac thoracic surgery. We conducted a retrospective review of all patients that<br />

had received ECMO after thoracic surgery at the University of Kentucky from January 9, 2012 to<br />

January 9, <strong>2017</strong>. We identified 8 patients. The average time on ECMO was 9.125 days, and the<br />

average hospital stay was 65.125 days. Of the eight patients placed on ECMO three of them survived<br />

to discharge. Of the 3 that survived to discharge one died within six months and two are less than<br />

four months out to follow up. The average charge per patient was calculated to be 1,053,551<br />

dollars, and the average charge per day for ECMO was 16,177 dollars. The contribution margin per<br />

case was $109,200. ECMO is a tool that saves lives, but ECMO does not appear to have the same<br />

yield in patients experiencing ARDS after Thoracic surgery compared to other patient groups.<br />

ECMO after non-cardiac thoracic surgery is low yield and costly compared to other patient<br />

populations.<br />

17


2<br />

Inhibition of Megalin Reduces Atherosclerosis and Improves Hypercholesterolemia-induced<br />

Lysosomal Dysfunction in Kidney<br />

Feiming Ye 1 • Chia-Hua Wu 1 • Deborah Howatt 1 • Adam Mullick 2 • Mark Graham 2 •<br />

Anju Balakrishnan 1 • Craig Vander Kooi 3 • Jan Danser 4 • Jian-An Wang 5 • Alan Daugherty 1 •<br />

Hong Lu 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Ionis Pharmaceuticals •<br />

3Molecular and Cellular Biochemistry, University of Kentucky • 4 Erasmus MC • 5 Department of<br />

Cardiology, Zhejiang University<br />

Graduate Student<br />

Objective: Our previous study has demonstrated that hepatocyte-specific deficiency of<br />

angiotensinogen (hepAGT-/-) reduces atherosclerosis. Megalin interacts with AGT and determines<br />

its presence in proximal convoluted tubules of kidney. In this study, we investigated effects of<br />

megalin inhibition on hypercholesterolemia-induced atherosclerosis and kidney pathologies.<br />

Methods and Results: Male LDL receptor -/- mice at the age of 8 - 10 weeks were injected<br />

subcutaneously with PBS, control antisense oligonucleotides (ASO), or megalin ASO for 13 weeks.<br />

One week after the initial injection, mice were fed a Western diet enriched with saturated fat for 12<br />

weeks. Inhibition of megalin profoundly reduced atherosclerotic lesion area, compared to the two<br />

control groups (Percent lesion area in PBS, control ASO and megalin ASO groups: 23 ± 2, 20 ± 2, 12<br />

± 1 %, respectively; P < 0.001). Histological analysis of kidney sections exhibited extensive vacuolar<br />

formation in proximal convoluted tubules of kidney in mice injected with PBS or control ASO, which<br />

were absent in mice injected with megalin ASO. Immunostaining of lysosomal-associated<br />

membrane protein 1 demonstrated that these vacuoles were derived from enlarged lysosomes.<br />

Same kidney pathology was also found in hepAGT+/+ mice in an LDL receptor -/- background fed<br />

the Western diet, but not observed in hepAGT-/- mice fed this diet.<br />

Conclusions: Megalin in proximal convoluted tubules of kidney and AGT derived from hepatocytes<br />

may interact to promote hypercholesterolemia-induced atherosclerosis and renal lysosomal<br />

dysfunction.<br />

18


3<br />

Improving Patient Care on Left Ventricular Assist Device Support: Novel Outcome Predictors<br />

& Preventative Therapies<br />

Tara Shrout 1 • Travis Sexton, PhD 2 • Susan Smyth, MD, PhD 3<br />

1College of Medicine, University of Kentucky • 2 Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of<br />

Kentucky • 3 Chief, Division of <strong>Cardiovascular</strong> Medicine, University of Kentucky<br />

Medical Student<br />

Background:<br />

Left ventricular assist device (LVAD) implantation is an increasingly common and important<br />

intervention for heart failure. Despite advancements, implantation introduces a foreign body across<br />

which blood experiences aberrant sheer stress. Clinical complications of bleeding and stroke<br />

develop secondary to an acquired coagulopathy, and patients’ quality of life is an important<br />

outcome to consider. This study uniquely correlates early platelet function and biomarkers<br />

alterations with clinical outcomes, as well as patient quality of life measures to help predict,<br />

address, and explore complications with LVAD support.<br />

Objectives:<br />

1. Evaluate correlations between predictive measures of platelet function, biomarkers, laboratory<br />

trends with clinical complications outcomes and LVAD types.<br />

2. Characterize the role of a novel hemostatic agent as a preventative therapy for bleeding.<br />

3. Understand patients’ quality of life on LVAD support.<br />

Design:<br />

March 2014-August 2016, 68 enrolled patients underwent implantation of Heartmate II (n= 48),<br />

Heartmate III (n=2), Heartware (n=18). Blood collections: 24-hours preoperatively and 1-, 24-, 72-,<br />

and 168-hours postoperatively. Follow-up collections: between 30-90-days postoperatively.<br />

Platelet function analyzed via impedance aggregometry, five agonists, and novel hemostatic agent.<br />

Biomarkers of coagulation, platelet activation, and inflammation analyzed. Daily clinical data<br />

collected.<br />

Participants:<br />

Consecutive-based sample. Sociodemographics: age, gender, ethnicity, co-existing conditions<br />

collected. Eligibility: First-time LVAD implant. Exclusion: Age


4<br />

Identification of a Lipid Signature in Clear Cell Renal Carcinoma (ccRCC) Suggest a Role of<br />

Phosphatidylinositol Remodeling in Disease Progression<br />

Chase Neumann 1 • Renliang Zhang, PhD 1 • Christopher Przybicin, MD 2 • Brian Rini, MD 3 •<br />

Mark Brown, PhD 1<br />

1Cellular and Molecular Medicine, Cleveland Clinic • 2 Robert J. Tomsich Pathology and Laboratory<br />

Medicine, Cleveland Clinic • 3 Hematology and Oncology Taussig Cancer Institute, Cleveland Clinic<br />

Graduate Student<br />

The most lethal urological cancer and third most common urological cancer in the United States is<br />

clear cell renal carcinoma (ccRCC). Approximately 64,000 individuals in the United States are<br />

diagnosed with ccRCC annually, and more than 140,000 individuals die worldwide of ccRCC every<br />

year. The “clear cell” characteristic of this deadly kidney cancer is due to abnormal deposition of<br />

lipids in a large unilocular lipid droplet in cancer cells, and urinary biomarker studies have<br />

identified lipid droplet-associated proteins as predictive markers of disease progression. However,<br />

the mechanisms by which lipid metabolism impacts ccRCC progression are not well understood. We<br />

hypothesized that a group of mitogenic lipids exist within the ccRCC microenvironment that<br />

promote proliferation and metastatic potential. A high throughput Triple Time-of-Flight (TOF) LC-<br />

MS/MS lipidomics screen of metastatic ccRCC tumor samples and matched non-tumor adjacent<br />

tissue identifies a highly reproducible lipid signature of ccRCC. In agreement with previous reports,<br />

cholesteryl esters are increased in the tumor vs non-tumor. We also found a striking increase in<br />

phosphatidylinositol (PI) 36:4 and 34:1 in tumors. Membrane bound O-acyltransferase domain<br />

containing 7 (MBOAT7) is a lysophosphatidylinositol (LPI) acyltransferase that preferentially<br />

utilizes arachidonyl-CoA and 16:0 LPI as substrates. To further investigate the formation of 36:4 PI,<br />

an MBOAT7 product, we used TCGA datasets to analyze stage-specific expression of MBOAT7.<br />

MBOAT7 expression was found to increase with staging. This potential increase in<br />

phosphatidylinositol production, coupled with decreases in known phosphatase activity like PTEN,<br />

SACM1L, and MTM1 may lead to increased activation of the PI3K/Akt signaling activity. The impact<br />

of this work may suggest mechanisms why some patients are refractory to PI3K/mTOR inhibitors,<br />

while a small percentage (


5<br />

Potential Role of Muscle Specific Ribosomal Protein L3-like in Cardiomyocyte Transverse<br />

Tubule Formation<br />

Laura Peterson 1 • Alexander Alimov, PhD 1 • Jon Satin, PhD 1 • Brian Delisle, PhD 1 •<br />

John McCarthy, PhD 1<br />

1Physiology, University of Kentucky<br />

Graduate Student<br />

Ribosomes have long been thought as serving in a constitutive housekeeping function and possess<br />

no real regulative capacity. Recently however, ribosomal proteins have been shown to provide the<br />

ribosome with a regulatory capacity across phyla. Ribosomal protein paralogs arose from a<br />

duplication event millions of years ago and have contributed to the development of ribosome<br />

specialization. By allowing a ribosome to function in its original capacity and acquire new roles,<br />

some ribosomal protein paralogs have acquired specialized roles. Ribosomal protein L3-like (RPL3-<br />

like) is expressed only in skeletal muscle and the heart but its paralog, RPL3, is found ubiquitously<br />

throughout the body. Strikingly, the expression in the heart is limited to the ventricles and is not<br />

expressed in the atria. One of the major anatomical differences in the atria and ventricle is the<br />

patterning of transverse tubules (t-tubules) with the ventricles exhibiting a highly symmetrical,<br />

regular transverse pattern and the atria having an irregular pattern with more prominent axial<br />

projections. RPL3-like knock out in the adult mouse disrupts ventricular t-tubule organization. We<br />

hypothesize that RPL3-like containing ribosomes preferentially associate with transcripts that<br />

encode for proteins involved in t-tubule formation thereby controlling morphology.<br />

21


6<br />

Serum Amyloid A Activates the NLRP3 Inflammasome in Macrophages<br />

Preetha Shridas, PhD 1 • Maria de Beer, PhD 2 • Nancy Webb, PhD 3<br />

1Internal Medicine, University of Kentucky • 2 Physiology, University of Kentucky • 3 Molecular and<br />

Biomedical Pharmacology, University of Kentucky<br />

Faculty<br />

Objectives: Interleukin-1beta (IL-1β) has been implicated in many chronic diseases including<br />

atherosclerosis and type 2 diabetes. Production of bioactive IL-1β is controlled by the<br />

inflammasome, a multi-protein complex that regulates caspase-1 activity. Serum Amyloid A (SAA) is<br />

an acute-phase protein whose levels in circulation can increase more than 1000-fold during severe<br />

infection and tissue damage. SAA is more modestly elevated in conditions associated with chronic<br />

inflammation, including obesity. SAA has been identified as the first known physiological mediator<br />

capable of activating the NRLP3 inflammasome. The objective of this study is to investigate the<br />

mechanisms involved in SAA-mediated inflammasome activation in macrophages.<br />

Methods/Results: J774 macrophage-like cells and mouse bone-marrow derived macrophages<br />

(BMM) were stimulated with 5-25 µg/ml purified lipid-free mouse SAA, concentrations<br />

corresponding to those typically observed in obese individuals. The analyses of culture media and<br />

cell lysates demonstrated that SAA dose-dependently induced both caspase-1 activation and IL-1β<br />

secretion. The ability of SAA to induce IL-1β secretion was significantly reduced in BMM deficient in<br />

NRLP3. There was significant suppression in IL-1β secretion by SAA when J774 cells were treated<br />

with SAA in the presence of caspase-1inhibitor, Z-YVAD-FMK. A P2X7-receptor antagonist,<br />

AA38079, did not have any effect on SAA-mediated IL-1β production. Inhibition of reactive oxygen<br />

species (ROS) and cathepsin-B activation by N-acetyl-L-cysteine and CA-074, respectively, inhibited<br />

inflammasome activation by SAA. Inhibiting cellular potassium efflux by glyburide also significantly<br />

reduced SAA-mediated IL-1β secretion. Pre-incubating SAA with HDL prior to cell treatments<br />

completely inhibited its ability to trigger inflammasome activation. HDL also abrogated SAAmediated<br />

ROS generation in J774 cells.<br />

Conclusions: SAA-mediated NRLP3 inflammasome activation in macrophages is dependent on ROS<br />

generation, release of cathepsin-B, and potassium efflux, and is independent of the P2X7 receptor.<br />

Ongoing studies are investigating the cellular receptor(s) involved and the mechanism by which<br />

lipoproteins mask SAA’s effects. Blocking SAA-mediated inflammasome activation may ameliorate<br />

increased risk for type 2 diabetes and atherosclerosis in obese individuals.<br />

22


7<br />

Diabetic Hfpef in a Rat Model of Systemic Amylin Dyshomeostasis<br />

Miao Liu, PhD 1 • Nirmal Verma, PhD 1 • Analia Loria, PhD 1 • Sanda Despa, PhD 1 •<br />

Florin Despa, PhD 1<br />

1Pharmacology and Nutritional Sciences, University of Kentucky<br />

Postdoc<br />

Diabetic heart failure with preserved ejection fraction (HFpEF) is a complex disease characterized<br />

by diastolic dysfunction, altered insulin sensitivity and multiple organ impairments. Amylin, a β-cell<br />

hormone co-secreted with insulin, participates in normal glucose regulation, but is also known to<br />

induce insulin resistance and to form pancreatic amyloid when oversecreted (hyperamylinemia).<br />

Accumulating data from several laboratories have confirmed that, in addition to pancreatic islets,<br />

the hearts, kidneys and brains of patients with type-2 diabetes contain also abnormally increased<br />

levels of aggregated amylin. Our overall hypothesis is that the interplay between insulin resistance<br />

and hyperamylinemia results in toxic accumulation of aggregated amylin in the microvasculature<br />

that adversely affects function of multiple organs, including, but not limited to, the heart. Here, we<br />

used rats overexpressing human amylin in the pancreas (HIP rats) to test whether a “human”<br />

hyperamylinemia predisposes to HFpEF. Wild-type (WT) littermates expressing non-amyloidogenic<br />

rat amylin served as control. Hearts and kidneys of HIP rats showed amylin deposition in<br />

capillaries, intravascular macrophage accumulation, microhemorrhages and loss of vascular<br />

endothelial cell coverage and tight junctions. These changes were associated with diastolic<br />

dysfunction, cardiac hypertrophy and mid-range cardiac ejection fraction (~50%). HIP rats also had<br />

increased blood pressure and renal dysfunction, including diuresis, natriuresis, creatinine clearance<br />

and microalbuminuria. Abundant amylin deposition was detected in HIP rat red blood cells (RBCs).<br />

Amylin-loaded RBCs have altered deformability and increased adherence to cultured endothelial<br />

cells. Intravenous infusion of RBCs from HIP rats in WT rats resulted in release of amylin in plasma<br />

and capillaries, attachment of RBCs to the vascular endothelium, intravascular macrophage<br />

accumulation and microhemorrhages. In conclusion, hyperamylinemia provokes systemic amylin<br />

dyshomeostasis which negatively affects cardiac and renal function via amylin-mediated<br />

microvascular injury. Circulating level of amylin may serve as a biomarker of diabetic HFpEF and<br />

therapeutic target to reduce the development/progression of HFpEF.<br />

23


8<br />

Azithromycin Therapy Reduces Cardiac Inflammation and Mitigates Adverse Cardiac<br />

Remodeling after Myocardial Infarction: Potential Therapeutic Targets<br />

Ahmed Al-Darraji, PharmD 1 • Dalia Haydar 2 • Lakshman Chelvarajan, PhD 3 • Himi Tripathi, PhD 3 •<br />

Bryana Levitan 4 • Shaojing Ye, PhD 3 • Vincent Venditto, PhD 5 • John Gensel, PhD 4 •<br />

David Feola, PhD 5 • Ahmed Abdel-Latif, MD, PhD 6<br />

1Pharmacology and Nutritional Sciences, University of Kentucky • 2 Pharmacy College, University of<br />

Kentucky • 3 SAHA cardiovascular center, University of Kentucky • 4 Physiology, University of<br />

Kentucky • 5 College of Pharmacy, University of Kentucky • 6 Cardiology, University of Kentucky<br />

Graduate Student<br />

<strong>Abstract</strong><br />

Introduction and Hypothesis:<br />

Acute myocardial infarction (MI) is a primary cause of worldwide morbidity and mortality.<br />

Macrophages are fundamental components of post-AMI inflammation. Pro-inflammatory<br />

macrophages (M1-like) can lead to adverse cardiac remodeling and heart failure while<br />

regulatory/reparative macrophages (M2-like) enhance tissue healing. Shifting the balance between<br />

M1 and M2 macrophages post-MI is a novel therapeutic strategy. Azithromycin (AZM), a commonly<br />

used macrolide antibiotic, polarizes macrophages towards an M2-like phenotype in animal and<br />

human studies. We hypothesized that using AZM can decrease adverse cardiac remodeling and<br />

improve heart function following MI.<br />

Methods and results:<br />

Male mice (C57BL/6, 6–8 weeks old) were treated with either oral AZM (160 mg/kg/day) or<br />

vehicle control starting 3 days prior to MI and continued to day 7 post-MI. We observed significant<br />

reduction in mortality with AZM therapy. AZM-treated mice showed reduction in M1-like<br />

(CD45+/Ly6G-/F4-80+/CD86+) and increase in M2-like (CD45+/Ly6G-/F4-80+/CD206+)<br />

macrophages leading to significant reduction in the M1/M2 ratio in the heart and peripheral blood<br />

as assessed by flow cytometry and immunohistochemistry. Macrophage changes were associated<br />

with significant reduction in pro-inflammatory and increase in anti-inflammatory cytokine<br />

production as assessed by real-time PCR. AZM treatment was associated with increased neutrophil<br />

apoptosis, a known signal for shifting macrophages towards an M2-like phenotype. Finally, AZM<br />

treatment was associated with enhanced cardiac recovery, smaller scar size and enhanced<br />

angiogenesis.<br />

Conclusion:<br />

Azithromycin plays a cardioprotective role post-MI through attenuating inflammation and<br />

enhancing cardiac recovery. Long term and human translational studies are planned to examine the<br />

therapeutic applications of AZM.<br />

24


9<br />

Cerebro-cardiac and Cerebro-respiratory Interactions while Listening to Songs<br />

Mohammad Javad Mollakazemi 1 • Dibyajyoti Biswal 1 • Sridevi Thyagarajan 1 • Joyce Evans 1 •<br />

Abhijit Patwardhan, PhD 1<br />

1 Biomedical Engineering, University of Kentucky<br />

Graduate Student<br />

Introduction: Since ancient times listening to music has been thought to affect mental as well as physical wellbeing.<br />

Previous studies have shown that autonomic responses change while listening to songs, but the interactions<br />

between respiratory, cardiovascular and cerebral rhythms while listening to songs are not as well understood. In<br />

this study, we investigated relations between cerebral, cardiac and respiratory rhythms while subjects listened to a<br />

variety of songs.<br />

Materials and Methods: All study procedures were approved by the Institutional Review Board at the University of<br />

Kentucky. Data were collected from 8 adult subjects (4 males and 4 females). A pair of circumaural headphones was<br />

used to listen to songs. A short audio acuity test was administered to each subject to rule out overt hearing loss. The<br />

following signals were recorded during the study: 6 channels of EEG (F3, T3, P3, F4, T4, P4), ECG (lead II,<br />

Spacelabs), Respiration (abdominal and thoracic, AMI Inductotrace) and non-invasive continuous finger blood<br />

pressure (Finapres). Some results from cardio-respiratory variables are reported in a companion abstract. All<br />

signals were digitized online at a rate of 1000 samples/second. In order to determine the contribution of cognition<br />

and memory recall in the evoked responses, we scrambled local phase spectra for a song of the subject’s choosing<br />

while preserving the magnitude spectra. In addition, subjects listened to two songs, one with a slow and the other<br />

with a fast tempo. Data were collected during 10 minutes of control at the beginning of the study when the subjects<br />

sat quietly in the chair without listening to any music. To find interactions between cerebro-cardiac and cerebrorespiratory<br />

rhythms, frequency spectra, magnitude squared coherencies and transfer functions were computed for<br />

all possible combinations of EEGs and cardiovascular variable (RR intervals, computed from the ECG) and between<br />

EEGs and respiratory time series. Welch’s method with 100 sec segments, 50% overlap and a Hanning window<br />

were used for these computations.<br />

Results and Discussion: Coherence, integrated over dc-0.5 Hz (the Nyquist frequency used for cardiac and<br />

respiratory variables) between RR intervals and most channels of EEG increased during listening to songs relative<br />

to control. An increase was seen regardless of the type of song that was listened to. A similar increase in integrated<br />

coherence was also observed between respiratory oscillations and EEGs, again, regardless of type of the song.<br />

Comparing slow and fast tempo songs: the fast tempo song increased the coherence between RR intervals and EEGs<br />

and between respiratory oscillations and EEGs more than the slow tempo song. When subjects listened to the song<br />

of their choosing, the average coherence between cerebro-cardiac and cerebro-respiratory rhythms was higher<br />

than control, the phase randomized version of the same song had a somewhat lower coherence but was still higher<br />

than control. However, differences in integrated cerebro-cardiac and cerebro-respiratory coherencies between the<br />

song of choice and the phase randomized version of it were not consistent. The autospectra of the envelopes of all<br />

channels of the EEG showed an overall decrease in spectral power within the 0-5 Hz range while listening to songs.<br />

Conclusions: Although we had anticipated that the differences between the responses for the song of choice and its<br />

phase scrambled version would be small, our results do not show a consistent difference. Many subjects could<br />

identify the phase scrambled song as being the same or similar to the one of their choosing, which may explain this<br />

finding. The increase in integrated coherencies between respiration and EEGs is indicative of entrainment of<br />

respiration to the music. The increase in coherencies between EEGs and RR intervals, during listening to songs, also<br />

indicates entrainment of RR intervals with music; however, whether this entrainment happens in parallel with<br />

entrainment with respiration or it is sequential remains unknown. Collectively, these results show that listening to<br />

songs increases coherent entrainment between cerebro-cardio and cerebro -respiratory variables.<br />

Acknowledgement: Supported by a grant from the National Science Foundation (EPSCoR RII Track-2).<br />

25


10<br />

Evidence of Angiotensin II-dependent Obesity-induced Hypertension in Female Mice<br />

Exposed to Postnatal Neglect<br />

Joseph Herald 1 • Jacqueline Leachman 1 • Analia Loria, PhD 1<br />

1Pharmacology and Nutritional Sciences, University of Kentucky<br />

Undergraduate<br />

Previously, we have shown that female mice subjected to maternal separation with early weaning<br />

(MSEW), a model of postnatal neglect, display exacerbated diet-induced obesity and high blood<br />

pressure (BP) compared with control mice. Female MSEW mice show activated renin-angiotensin<br />

system components, including increased plasma renin activity and adipose tissue-derived<br />

angiotensinogen secretion. The goal of this study was to test whether augmented obesity-induced<br />

hypertension in female MSEW mice is AngII-dependent. Mouse MSEW was achieved by repeated,<br />

daily separations from the dam and 4-day early weaning. Normally reared controls (C) were<br />

weaned at postnatal day 21. Each experimental group of female weanlings was comprised of 6 mice<br />

each and derived from 3 different litters, that were placed on high fat diet (HFD, 60% kcal from fat).<br />

After 18 weeks, mice were implanted with radiotelemetry devices for BP measurement. At week 20,<br />

average 24-hr systolic blood pressure (SBP) was 134±2 mmHg in MSEW mice and 126±2 in C<br />

(P


11<br />

Cardiac Specific Rad Deletion Enhances Cardiac Function through Safe, Stable Positive<br />

Inotropic Support<br />

Brooke Ahern 1 • Bryana Levitan 2 • Mihir Shah 1 • Andrea Sebastian 1 • Zach Bessinger 3 • Radu<br />

Paul Mihail 3 • Landon Simpson 4 • Nathan Jacobs, PhD 3 • Douglas Andres, PhD 4 •<br />

Jonathan Satin, PhD 1<br />

1Physiology, University of Kentucky • 2 Gill Heart and Vascular Institute, University of Kentucky •<br />

3Computer Science, University of Kentucky • 4 Biochemistry, University of Kentucky<br />

Graduate Student<br />

Background: The cardiac L-type Calcium Channel (LTCC) is a heteromultimeric protein complex.<br />

Rad interacts with the main pore forming subunit (CaV1.2) and auxiliary subunit CaVβ2. Rad<br />

modifies LTCC function and Rad protein levels are reduced by pathological stimuli. Global,<br />

constitutive deletion of Rad results in an increase in calcium handling and improved ejection<br />

fraction without progression to heart failure.<br />

Goals: It is unknown if the effects of global Rad deletion are also exhibited in cardiac-specific Rad<br />

deletion, and if the effects are preserved long-term. Our hypothesis is that cardiac-specific Rad<br />

ablation causes positive inotropic effects that are maintained over time.<br />

Methods and Results: We crossed Radfl/fl onto αMHC-MerCreMer mice to create a cardiacrestricted<br />

inducible Rad knockout (cRadKO). Mice were induced for gene deletion at ~3 months of<br />

age. We assessed cardiac structure and function through echocardiography from 7 days through 9<br />

months after cRadKO induction. Ejection fraction improved in females in comparison to wild type 7<br />

days post knock out (762% vs. 594%; cRadKO n=16 vs. WT n=7, respectively; p=0.001). Improved<br />

function was stable for 9 months in females (774% vs. 587%;cRadKO vs. WT, respectively; p=0.01).<br />

Similar results were found in males. The key mechanism for improved function includes elevated<br />

trigger Ca2+ in cardiomyocytes measured as a Ca2+-transient departure velocity (48.72.4 units/s<br />

vs. 38.13.4 units/s; cRadKO n=8 vs. WT n=10, respectively; p=.014). Cellular Ca2+ synchrony was<br />

preserved in cRadKO despite chronic elevated Ca2+ homeostasis.<br />

Conclusion: Cardiomyocyte Rad deletion preserves increased ejection fraction over time through a<br />

mechanism including increased calcium handling resulting in safe, stable positive inotropic support<br />

for heart function.<br />

27


12<br />

Auditory Entrainment of Respiration and RR Intervals<br />

Dibyajyoti Biswal, PhD 1 • Javad Mohammad Mollakazemi, PhD 1 • Sridevi Thyagarajan, PhD 1 •<br />

Joyce Evans, PhD 1 • Abhijit Patwardhan, PhD 1<br />

1 Biomedical Engineering, University of Kentucky<br />

Graduate Student<br />

Introduction:- It is known that music has palliative effect in a number of patients. Listening to music is also<br />

known to evoke autonomically regulated cardiovascular and respiratory responses. In adults, these responses<br />

are a combination of sensory input and cognition. While it is known that listening to music evokes<br />

measurable responses in cardiovascular and respiratory variables,<br />

much is unknown in terms of causal links between these responses and the mechanisms by which they get<br />

entrained. Our overall objective is to determine the causal links between auditory stimuli, respiration and<br />

cardiovascular regulatory variables.<br />

Materials and Methods:- The study was approved by the Institutional Review Board at the University of<br />

Kentucky. Subjects gave informed consent. Subjects (n=8, equal numbers of males and females, age 18 to 35)<br />

sat in a comfortable chair and listened to songs through a pair of circumaural headphones. An internet based<br />

audio acuity test was administered to each subject to rule out overt hearing loss. The following<br />

measurements were made: non-invasive continuous finger blood pressure (Portapres, Finapres), ECG (lead II,<br />

Spacelabs), Respiration (abdominal and thoracic, AMI Inductotrace) and EEG. Results of analyses using EEG is<br />

reported elsewhere. All signals were digitized on-line at a rate of 1000 samples/second. To align the<br />

physiological data with the music, a square wave pulse was inserted at the beginning of the songs. For each<br />

study, the subject was asked to provide a song of their choice which in their opinion “moves” them. Data were<br />

collected during 5 trials in each study: control (10 minutes), songs of slow and fast tempo, the song of the<br />

subject’s choice, and a phase scrambled version of the song of the subjects’ choice. Each song was 3-4 minutes<br />

long. To minimize cognitive response, we scrambled the phase of the song of the subject’s chosen song by<br />

segmenting the songs and scrambling the phase spectrum of that segment while preserving the magnitude<br />

spectrum. From the recorded data, time series of RR intervals were generated. These time series and the<br />

respiratory signals were low pass filtered (cut off 5Hz) and subsampled at a rate of 10 samples/second. From<br />

the subsampled data auto-spectra of RR intervals and respiration, coherencies and transfer functions<br />

between these signals were computed using Welch’s method.<br />

Results and Discussion:- The most pronounced effect during listening to songs was in respiration. In all but<br />

one subject, the mean respiratory rate increased relative to control while listening to songs. In addition to an<br />

increase in mean rate, the power distribution in the autospectra of respiration markedly narrowed during<br />

auditory stimulation. Similar changes were seen in RR interval spectra, the so called HF power, i.e. respiratory<br />

region power, was more narrowly distributed while listening to songs. Coherence between RR intervals and<br />

respiration exhibited a broad band increase during listening to songs as compared with control. Although<br />

there was a slight tendency during phase scrambled song for respiratory spectra to move closer to those<br />

during control, these differences were not very robust.<br />

Conclusion:- Our results show that auditory stimulation does entrain respiration as well as RR interval. Taken<br />

together, these results suggest that RR intervals were entrained by respiration while listening to both slow<br />

and fast tempo songs. The increase in average coherencies suggests entrainment of respiration to auditory<br />

stimulation which in turn entrains RR intervals. Further analyses using phase synchronization indexes would<br />

be useful to better reveal the causal links in these entrainment processes.<br />

Supported by a grant from the National Science Foundation (EPSCoR RII Track-2).<br />

28


13<br />

An Unbiased Classification Algorithm for Transverse Tubule Remodeling Within Murine<br />

Heart Failure Models.<br />

Dylan Colli 1 • Bradley Stewart 2 • Peter Kekenes-Huskey, PhD 2<br />

1Chemical and Materials Engineering, University of Kentucky • 2 Chemistry, University of Kentucky<br />

Undergraduate<br />

Transverse tubules (TTs) are the main method of delivery of extracellular calcium into the myocyte,<br />

responsible for the initiation of calcium induced calcium release (CICR) necessary to carry out<br />

excitation contraction coupling (EC coupling) within ventricular myocytes. Disruptions in the<br />

regularly striated TT network are correlated with various degrees of calcium mishandling and are<br />

generally observed within heart failure models. Currently, TT remodeling is often judged<br />

qualitatively, subject to bias of the experimenter. To address the need to eliminate this bias, we<br />

propose a technique that utilizes: 1. Computer vision libraries. 2. Signal processing techniques such<br />

as matched filtering that provide signal-to-noise ratios, a quantitative measure of observed<br />

remodeling. Combining these methods, an unbiased classification algorithm is presented that is<br />

able to quantify both regions of TT loss and longitudinal remodeling as well as characterize whole<br />

myocytes by the magnitude of their deviation from the prototypical healthy myocyte. This allows<br />

for the expedient, and more importantly, unbiased and reliable classification of TT remodeling<br />

observed within murine ventricular myocytes.<br />

29


14<br />

Cardiac specific Rad knockout Increases Calcium Release<br />

Mihir Shah 1 • Andrea Sebastian 1 • Landon Simpson 2 • Doug Andres, PhD 2 • Jonathan Satin, PhD 1 •<br />

Brooke Ahern 1<br />

1Physiology, University of Kentucky • 2 Biochemistry, University of Kentucky<br />

Undergraduate<br />

Background: The L-type calcium channel complex (LTCC) associates with regulatory proteins<br />

including Rad that govern calcium channel function. Overexpression of Rad inhibits LTCC inward<br />

calcium current. In contrast, whole body constitutive Rad knockout in mice have higher calcium<br />

influx in cardiac myocytes. It is unknown whether the effect of constitutive whole body Rad<br />

knockout arise from development, from the influence of non-cardiac myocytes, or is a primary<br />

result of Rad reduction in cardiac myocytes. Our recently engineered inducible, cardiac myocyte<br />

restricted Rad-knockout mouse model allows us to address these possibilities.<br />

Hypothesis: Cardiac specific Rad knockout will recapitulate the same effects of global Rad knockout.<br />

Acute induction (1-4 weeks) of Rad knock out produces an immediate effect on cytosolic calcium<br />

entry.<br />

Methods: Cytosolic Ca2+ in single, live cells were analyzed using Fura-2. Cells were paced at 1 Hz.<br />

Twitch calcium, calcium reuptake, and release kinetics were measured before and after the addition<br />

of isoproterenol in both wild-type (Radfl/fl abbreviated as WT) and induced, Rad-/-<br />

cardiomyocytes (cRadKO).<br />

Results: Twitch calcium levels were significantly higher in cRadKO compared to WT (1.99±0.09 and<br />

1.54±0.13 FU for WT and RadKO, respectively, p=0.008). cRadKO and WT twitch calcium<br />

significantly increased in response to acute isoproterenol (ISO; 2.63±0.13 and was 1.98±0.20 FU for<br />

WT and RadKO, respectively, p=0.0082). Calcium reuptake also increased with the knockout of Rad<br />

and in the presence of ISO. The onset velocity of calcium release increased in cRadKO (38.13±3.46<br />

FU/ms and 48.71±2.38 FU/ms, for WT and cRadKO, respectively, p=0.01). The ISO response for<br />

onset velocity was retained with cRadKO, in parallel with amplitude effects.<br />

Conclusion: Reduction of Rad protein elevated baseline cytosolic calcium levels approaching that of<br />

ISO-stimulated WT cardiomyocytes. Thus, Rad knockout provides positive inotropic support to<br />

heart function by elevating baseline cytosolic Ca2+. cRadKO maintains modulated myocardial<br />

function to sympathetic activity.<br />

30


15<br />

Atherosclerosis in the Cerebrovasculature of Nonhuman Primates Promotes Reactive<br />

Gliosis: A Potential Model for Vascular Dementia<br />

Peter Hecker 1 • Lei Cai, PhD 1 • Elizabeth Head, PhD 2 • Donna M. Wilcock, PhD 3 • Ryan Temel, PhD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center and Department of Pharmacology and Nutritional Sciences,<br />

University of Kentucky • 2 Sanders-Brown Center of Aging and Department of Pharmacology and<br />

Nutritional Sciences, University of Kentucky • 3 Sanders-Brown Center of Aging and Department of<br />

Physiology, University of Kentucky<br />

Graduate Student<br />

Age- and lifestyle-dependent vascular insults drive and/or exacerbate cardio- and cerebro- vascular<br />

disease. While several animal models exist for studying vascular contributions to cardiovascular<br />

disease there are few models for studying the vascular contributions to cognitive impairment and<br />

dementia (VCID). Our lab is studying atherosclerosis progression and regression in male<br />

cynomolgus monkeys fed a high-fat/high-cholesterol diet. After 20 months on the atherogenic diet,<br />

a subset of monkeys are switched to standard nonhuman primate “chow” diet and are<br />

concomitantly treated with vehicle or a microRNA-33 antagonist (anti-miR-33). We hypothesize<br />

that anti-miR-33 treatment will create more stable atherosclerotic plaques by increasing<br />

cholesterol efflux from foam cells and dampening inflammation in the artery wall. While our initial<br />

interest was atherosclerosis in the coronary arteries, we have recently turned our attention to<br />

atherosclerosis in the main arterial network that supplies the brain. Evaluation of the circle of<br />

Willis (COW) revealed the presence of atherosclerotic plaques in major branch points of the large<br />

arteries. Immunohistochemistry (IHC) on arterial sections has begun to evaluate the size and<br />

molecular/cellular composition of these atherosclerotic plaques. Understanding that<br />

atherosclerosis could reduce cerebral blood flow (CBF) and/or promote endothelial dysfunction,<br />

we have started to examine brain sections from our monkeys for underlying neuropathology.<br />

Preliminary IHC data shows increased microglia and astrocyte reactivity around small cerebral<br />

vessels from a monkey with atherosclerosis versus a healthy, control animal. The marked increase<br />

in glial reactivity around small vessels may suggest extravasation or decreased CBF, both capable of<br />

driving neuroinflammation and downstream neurodegeneration. In the near future, we plan to pair<br />

MRI analysis of hypoperfusion and white matter lesions (WML) with histology and IHC assessments<br />

of WML, cerebral amyloid angiopathy, and astrocyte endfeet engagement with the vasculature.<br />

Although much work remains to be done, we are optimistic that we have created a unique and<br />

important translational model that mimics human cerebrovascular atherosclerosis and<br />

neuropathology associated with VCID.<br />

31


16<br />

Hypercholesterolemia Induces Acute Thymic Atrophy Through Blocking Thymocyte<br />

Differentiation and Expansion<br />

Xiang Ye, PhD 1 • XiangAn Li, PhD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Postdoc<br />

Background: Thymus is the primary site for T cell development, however its function is decreasing<br />

with age, defined as thymic involution. The age-related thymic atrophy reduces the ability to<br />

produce naïve T cells, which is one of the main factors contributes to lower immune-surveillance in<br />

the elderly. Other than aging, thymic atrophy also can be accelerated by various stressors, like<br />

chemotherapy, corticosteroids, disturbed lipid metabolism, infection, inflammation and<br />

psychological stress. However, our knowledge on thymic atrophy is very limited. Here we report<br />

that hypercholesterolemia induces acute thymic atrophy through inhibiting thymocyte expansion<br />

and differentiation.<br />

Methods and Results: To investigate the role of hypercholesterolemia, we use albumin driven cre to<br />

specifically knock out SRBI in the liver, causing defect in reverse cholesterol transport and thus<br />

hypercholesterolemia. One week of HCD induces acute thymic atrophy (thymus weight:<br />

SRBIflox/flox vs SRBIflox/flox-Alb-Cre, 28.22mg vs 9.28mg, p < 0.0001) in RCT defected mice, and a<br />

more dramatic decrease of thymocyte cellularity (5.9 X 10E7 vs 4.5 X 10E6). In order to know what<br />

happened with T cell development, we profiled development process using flowcytometry with<br />

CD4, CD8a, CD44 and CD25. We found that CD4+CD8a+ cell decreases to be only 18% of thymocyte<br />

from more than 80%, which indicates blocks in thymocyte differentiation. Besides, we also see an<br />

increase of DN1 (CD4-CD8a-CD25-CD44+) progenitor cells increased from 17% to 38% of double<br />

negatives (CD4-CD8a-). To exclude the possibility of accelerated cell apoptosis of certain cell type<br />

rather than ceased differentiation, we measured thymocyte apoptosis using annexin V staining. The<br />

results only show a very mild increase in cell apoptosis (annexin V+: 8% vs 11%) after 3 days of<br />

HCD treatment, which could not explain the dramatic change in thymocytes numbers alone. Then<br />

we performed gene expression profile on the thymus from mice after 3 days of HCD. Gene<br />

enrichment analysis using the differentially expressed genes reveals an enrichment of cell cycle<br />

genes, with many cell cycle-promoting genes decreased and cell cycle inhibiting genes increased.<br />

Consistently, BrdU incorporation combined with 7-AAD staining also indicates impaired thymocyte<br />

proliferation, the thymocytes reside in G2-M phase decrease from 2.8% to 1.7% of total thymocytes.<br />

The earlier developing cells are most impacted, with G2-M cells decrease from 5.3% to 1.4% of DN.<br />

Conclusions: Hypercholesterolemia induces acute thymic atrophy through inhibiting thymocyte<br />

expansion and differentiation. This study indicates high cholesterol diet could exert its impact on<br />

immune system through accelerating thymic atrophy.<br />

32


17<br />

Cardiac Cycle Affects Ultrasound Measurements of Ascending Aortic Diameter in a Marfan<br />

Mouse Model<br />

Zheying Chen 1 • Hisashi Sawada, MD, PhD 1 • Debra Rateri 1 • Alan Daugherty 1 •<br />

Mary Sheppard, MD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Graduate Student<br />

Objective:<br />

Ultrasound measurements of aortic diameter are a common endpoint in preclinical studies.<br />

However, there is a lack of standardization in both image capture and analysis. For our study, we<br />

developed a standardized protocol for measuring ascending aortic diameter and examined effects<br />

of cardiac cycle in wild type and fibrillin-1 hypomorphic (FBN1mgR/mgR) mice.<br />

Methods and Results:<br />

Twelve week old male and female FBN1mgR/mgR mice were anesthetized and maintained at a<br />

heart rate of 450-550 beats per minute. Ultrasound images were captured using a Vevo 2100<br />

system with a 40MHz tranducer. Images captured were standardized according to two anatomical<br />

landmarks: the innominate artery branchpoint and aortic valves. The largest luminal ascending<br />

aortic diameter between the sinotubular junction and the innominate artery were measured in<br />

mid-systole and end-diastole by two blinded, independent observers. Aortic diameters were<br />

significantly different (p


18<br />

A Novel Approach for Modifying Intrinsic Heart Rate: RRad knock-down<br />

Bryana Levitan 1 • Mihir Shah 2 • Joshua Rutland, MD 1 • Brooke Ahern 3 • Douglas Andres, PhD 4 •<br />

Jonathan Satin, PhD 3<br />

1Cardiology, University of Kentucky • 2 University of Kentucky • 3 Physiology, University of Kentucky<br />

• 4 Molecular and Cellular Biochemistry, University of Kentucky<br />

Staff<br />

Introduction: About 3 million people worldwide are dependent on pacemakers. Each year 600,000<br />

pacemakers are implanted worldwide, for the primary indication of symptomatic bradycardia. Biological<br />

pacemakers represent an emerging technology for bradyarrhythmias that require a pacemaker such as<br />

sinoatrial nodal failure due to congenital disease or aging. Leading edge biological pacemaker<br />

approaches include implantation of induced, pluripotent stem cell-derived cardiomyocytes (iPSC-CMs);<br />

however, intrinsic rates of implanted cells might be insufficient to meet physiologic demands, and cell<br />

implantation carries a variety of obstacles. In the present report, we introduce a novel molecular<br />

mechanism for increasing heart rate. Rad is a monomeric G-protein and constituent of the L-type<br />

calcium channel macromolecular complex (LTCC). Rad inhibits LTCC inward calcium current. LTCC<br />

activity contributes to pacemaker depolarization. Therefore, we tested the hypothesis that reduction of<br />

cardiac Rad will result in a stable increased heart rate (HR). We suggest that knockdown of cardiac Rad<br />

could facilitate the development of rate support alone or in combination with cells as a biologic<br />

pacemaker.<br />

Methods & Experimental Design: Cardiac-restricted, inducible Rad knockout (cRadKO) female mice were<br />

implanted with radio-telemeters (model F10A, DSI, Minneapolis MN). Baseline recordings (continuous<br />

72h) were followed by induction of Rad knockout (RadKO). Continuous recordings followed induction of<br />

RadKO at times specified in results. Intrinsic heart rate was measured after complete autonomic<br />

blockade with injection of propranolol (1 mg/kg) and atropine (1 mg/kg). Peak heart rate was achieved<br />

by injection of isoproterenol (ISO) at diurnal peak. Startle response was performed using a series of air<br />

jet challenges to provoke an increase in native adrenergic stimulation.<br />

Results: Baseline measures demonstrated normal diurnal rhythms of HR (daytime trough, night-time<br />

peak) without evidence of significant arrhythmias. Trough HR increased without evidence of significant<br />

arrhythmias 4 days post cRadKO, while peak HR remained unchanged. The increase in trough HR was<br />

sustained 1 month after cRadKO. During trough periods episodes of sinus bradycardia without SA node<br />

or AV node block were noted consistent with high vagal tone. Intrinsic HR was also significantly<br />

increased post-cRadKO over baseline. ISO challenge induced sinus tachycardia with a blunted response<br />

as compared to controls. During recovery 1-8 hours after ISO challenge both cRadKO and control mice<br />

exhibited transient episodes of bradyarrhythmias. All animals returned to pre-ISO rhythm without<br />

incident. The startle response did not elicit arrhythmias.<br />

Conclusion: Cardiac Rad deletion results in a stable increase in intrinsic heart rate with retained<br />

physiologic autonomic responsiveness. Rad depletion did not induce any significant arrhythmias under<br />

physiological stressors. We conclude that inhibition of Rad can be used to increase the intrinsic heart<br />

rate. This could represent a novel mechanism for tuning iPSC-CMs to more physiologic heart rates.<br />

34


19<br />

Inflammasome Activation Triggers Blood Coagulation through Pyroptosis<br />

Congqing Wu, PhD 1<br />

1CVRC, College of Medicine<br />

Postdoc<br />

Disseminated intravascular coagulation (DIC) is a fatal complication of systemic bacterial infection.<br />

Mechanisms for blood coagulation induced by bacterial infection are often attributed to host<br />

inflammatory response to bacterial virulence factors, yet the molecular events linking bacteria<br />

sensing to initiation of the coagulation cascade remain unclear. Here we identify inflammasome<br />

activation as a trigger for coagulation induced by gram-negative bacterial products. Specifically,<br />

canonical inflammasome activation elicited by the conserved type III secretion system (T3SS) rod<br />

protein EprJ from E. coli induces systemic coagulation through caspase-1 activation, whereas<br />

noncanonical inflammasome activation by lipopolysaccharide (LPS), a major outer membrane<br />

component of gram-negative bacteria, produces similar effects involving caspase-11. Deficiency of<br />

gasdermin D (Gsdmd) or depletion of monocytes and macrophages blocks inflammasome-mediated<br />

coagulation. Together, our data unveil inflammasome-dependent pyroptosis leads to blood<br />

coagulation.<br />

35


20<br />

Clinical Use of the Amplatzer Septal Occluder in Percutaneous Closure: A Single-Center<br />

Experience<br />

Seema Rao, MS 1 • Tyler Scaff 1 • John Gurley, MD 2 • Sibu Saha, MD 3<br />

1College of Medicine, University of Kentucky • 2 Cardiology, University of Kentucky • 3 Cardiothoracic<br />

Surgery, University of Kentucky<br />

Medical Student<br />

Device therapy is a viable alternative to open heart surgery in the management of intracardiac<br />

defects. The Amplatzer Septal Occluder (ASO) is one such device that has been adapted to close a<br />

wide variety of cardiac defects with few complications and a high success rate. This is a<br />

retrospective review of all the patients who received the ASO between 2012-2016 at our<br />

institution. In total, 169 patients underwent percutaneous closure of a septal defect with Amplatzer<br />

during the timeframe studied, and of those, 91% received the device for an atrial septal defect or<br />

patent foramen ovale. All Amplatzer devices achieved successful closure without requiring a second<br />

procedure. Four patients sustained complications of the procedure, with two experiencing<br />

tamponade, one with hematoma, and one with cellulitis. Three fatalities occurred within thirty days<br />

and were attributed to comorbidities not related to the device. The ASO has performed very well at<br />

our institution and we expect it to serve additional functions as the field of transcatheter cardiology<br />

develops.<br />

36


21<br />

Exposure to PCB126 during the Nursing Period Significantly Impairs Early-Life Glucose<br />

Tolerance<br />

Keegan Sammons 1 • Sara Tenlep, MS 1 • Leryn Reynolds, PhD 1 • Hollie Swanson, PhD 1 •<br />

Kevin Pearson, PhD 1<br />

1Pharmacology and Nutritional Sciences, University of Kentucky<br />

Undergraduate<br />

Polychlorinated Biphenyls (PCBs) are persistent environmental organic pollutants that are known<br />

to have detrimental health effects. In a mouse model in our lab, PCB126 exposure during pregnancy<br />

and nursing alters offspring body composition and glucose tolerance. The purpose of this study was<br />

to expose dams to PCB126 during the nursing period only. Female ICR mice were bred and half of<br />

the dams were exposed to either vehicle (safflower oil) or 1 µmole PCB126 per kg of body weight<br />

via oral gavage on postnatal days 3, 10, and 17 (n = 9/group). Offspring body weight, lean and fat<br />

mass, and glucose tolerance were measured. Both male and female offspring displayed normal body<br />

weights as well as body composition (p > 0.05). However, both male and female offspring that were<br />

exposed to PCBs during the nursing period had significantly impaired glucose tolerance at 3 weeks<br />

of age (p < 0.05). This persisted until 9 weeks of age in the female offspring (p < 0.05), but the<br />

difference disappeared as the male offspring aged (p > 0.05). Our earlier work suggests that in<br />

utero and postnatal PCB126 exposure predisposes offspring to having lower lean mass and<br />

impaired glucose tolerance later in life. However, our current study shows that exposure to PCB126<br />

through the mother's milk impairs glucose tolerance in the short-term and is likely caused by<br />

impairments in insulin receptor signaling in the periphery as others have shown with direct PCB<br />

exposures in adult mice. Future experiments will investigate the mechanisms of dysfunction caused<br />

by in utero PCB126 exposure, which may be driving the increased risk of obesity and insulin<br />

resistance in adult offspring.<br />

37


22<br />

Regulation of Akt Signaling by NQO1<br />

Joshua Preston 1 • Andrea Di Francesco, PhD 2 • Krystle Kalafut 2 • Tyler Rhinesmith 2 • Clara Di<br />

Germanio, PhD 2 • Michel Bernier, PhD 2 • Rafael de Cabo, PhD 2<br />

1Pharmacology and Nutritional Sciences, University of Kentucky • 2 Translational Gerontology<br />

Branch, National Institute on Aging, National Institutes of Health<br />

Undergraduate<br />

Background: NQO1 is an inducible quinone reductase that participates in the cellular defense<br />

system in response to chemical and oxidative stress. By using NAD(P)H as electron donor, NQO1<br />

enzymatic activity shifts the cellular redox state leading to a significant increase in the NAD+/NADH<br />

ratio. The propensity of NQO1 knockout mice to exhibit a diabetes-like phenotype and a null NQO1<br />

polymorphism associated with metabolic syndrome phenotypes in humans suggests a role for this<br />

enzyme in cellular energetics and metabolism. Here, we explored a possible link between NQO1, an<br />

intracellular generator of NAD+, and nutrient-sensitive NAD+-dependent deacetylase activity in the<br />

regulation of Akt, which plays a central role in regulating cellular signaling and energy pathways<br />

critically involved in type 2 diabetes and associated metabolic disorders.<br />

Results: Pharmacological inhibition of NQO1 with the mechanism-based inhibitor Mac609<br />

increased insulin-stimulated Akt phosphorylation in HepG2 and HeLa cell lines. Consistent with<br />

increased Akt activation, Mac609 promoted nuclear exclusion and inactivation of the downstream<br />

Akt targets, the gluconeogenic transcription factors forkhead box O1 (FOXO1) and O3 (FOXO3a) in<br />

liver-derived HepG2 cells treated with insulin. Conversely, siRNA-mediated NQO1 knockdown<br />

increased insulin- or serum-stimulated Akt phosphorylation. Similarly, MDA-MB-468 cells, which<br />

carry a polymorphic form of NQO1 that results in an absence of NQO1 protein and activity, showed<br />

markedly higher constitutive and insulin-stimulated Akt phosphorylation levels compared to an<br />

isogenic cell line stably expressing NQO1. We then explored the impact of pharmacological<br />

inhibition or genetic down-regulation of NQO1 on the global pattern of protein acetylation in HeLa<br />

cells. The reduction in NQO1 level and/or activity was associated with an increase in protein<br />

acetylation levels likely due to the inhibition of NAD+-dependent sirtuins. Lastly, cell treatment<br />

with the NAD+ precursor nicotinamide mononucleotide (NMN) inhibited Akt phosphorylation in a<br />

dose- and time-dependent manner, thus recapitulating the effects of NQO1 on Akt activity.<br />

Conclusions: We have identified a molecular mechanism whereby NQO1 functions as a modulator<br />

of insulin/Akt signaling pathway. These findings have implications for future basic and<br />

translational research on pathways that control energy homeostasis and diabetes.<br />

38


23<br />

Substitution of Leu11 and Tyr12 in Mouse Angiotensinogen Does Not Affect Angiotensin IImediated<br />

Functions in Mice<br />

Chia-Hua Wu 1 • Congqing Wu 1 • Feiming Ye 1 • Deborah Howatt 1 • Anju Balakrishnan 1 •<br />

Jessica Moorleghen 1 • Craig Vander Kooi 2 • Alan Daugherty 3 • Hong Lu 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center , University of Kentucky • 2 Molecular and Cellular<br />

Pharmacology, University of Kentucky • 3 Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of<br />

Kentucky<br />

Graduate Student<br />

Background and Objective: Angiotensinogen (AGT) is the unique precursor of angiotensin II<br />

(AngII), which is a critical contributor to atherogenesis. Renin cleavage of AGT exhibits species<br />

specificity. It has been determined in in vitro studies that Leu11-Tyr12 in mouse AGT and Val11-<br />

Ile12 in human AGT are essential for species-specific renin cleavage. In this study, we compared<br />

adeno-associated viral (AAV) vectors encoding human AGT or mouse AGT with Leu11Val and<br />

Tyr12Ile mutations to determine whether substitution of these residues regulated AngII-mediated<br />

functions.<br />

Methods and Results: Male hepatocyte-specific AGT deficient (hepAGT-/-) mice were injected<br />

intraperitoneally with AAV vector containing a null insert or encoding human AGT, while their wild<br />

type littermates (hepAGT+/+) were injected with AAV containing the null insert. All mice were in<br />

an LDLR -/- background. Two weeks after AAV injections, mice were fed a saturated fat-enriched<br />

diet for 12 weeks. Administration of AAV encoding human AGT led to high plasma human AGT<br />

concentrations, but had no effect on plasma renin concentrations and hypercholesterolemiainduced<br />

atherosclerosis. In a subsequent study, AAV encoding mutated mouse AGT with Leu11Val<br />

and Tyr12Ile were injected into hepAGT-/- mice. Mutated mouse AGT resulted in a significant<br />

increase of plasma AGT concentrations. Plasma renin concentrations in hepAGT-/- mice<br />

repopulated with mutated mouse AGT were decreased to a level comparable to their<br />

concentrations in hepAGT+/+ mice injected with a null AAV. AAV-driven expression of mutated<br />

mouse AGT also augmented atherosclerosis in hepAGT-/- mice.<br />

Conclusion: Human AGT does not repopulate AngII-mediated functions, whereas mutations of<br />

Leu11Val and Tyr12Ile in mouse AGT, to mimic the two amino acids in human AGT, does not affect<br />

AngII-mediated effects.<br />

39


24<br />

Vascular Inflammatory Regulation of Lipid Phosphate Phosphatase 3 Expression<br />

Patrick Van Hoose, PhD 1 • Andrew Morris, PhD 1 • Susan Smyth, MD, PhD 1<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Postdoc<br />

Lipid phosphate phosphatase 3 (LPP3), encoded by the PLPP3, is a cell surface enzyme that<br />

regulates lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) availability and<br />

signaling. Genome wide association studies in humans identified heritable single nucleotide<br />

polymorphisms (SNPs) in the final intron of PLPP3 that independently predicted coronary artery<br />

disease (odds ratio, 1.17; P=3.81×10–19). PLPP3 is dynamically regulated during vascular<br />

inflammation and the risk allele reduces gene expression by disrupting binding of CCAAT enhancer<br />

binding protein beta (CEBPβ). However, other mechanisms may control dynamic regulation of<br />

PLPP3. The USC Genome Browser identifies potential target sequences for NFκB responsive<br />

elements in the PLPP3 promoter, including three potential RelA (p65) binding sites. Previous work<br />

has established that smooth muscle expression of Plpp3 attenuates experimental atherosclerosis<br />

and development of intimal hyperplasia.These observations led to the hypothesis that dynamic<br />

regulation of PLPP3 is a crucial step in controlling vascular inflammation and disease progression.<br />

Coronary human smooth muscle cells (caHSMCs) were treated for 72hrs with 1µM angiotensin II<br />

(ATII) in the presence or absence of 1 µM parthenolide. Ldlr-/- mice were randomized to receive<br />

either vehicle saline or 1000ng/kg/min angiotensin II via osmotic mini-pump for 7 days. Following<br />

72hr exposure to angiotensin II (ATII) PLPP3 expression increases in caHSMCs and is accompanied<br />

by increases in p65 but not CEBPβ expression. Parthenolide, an inhibitor of IκBα degradation,<br />

blocks ATII induced PLPP3 expression. To determine whether Plpp3 is upregulated in response to<br />

ATII in vivo, Ldlr-/- mice were treated with ATII for 7 days. Plpp3 and p65 expression remained<br />

unchanged in the aortic arch, thoracic aorta, abdominal aorta and mesenteric arteries.These<br />

observations suggest potential novel regulation of PLPP3 expression governed by an ATII-NFκB<br />

pathway that could be important in the context of vascular inflammation and disease.<br />

40


25<br />

Myeloid β-catenin deficiency exacerbates atherosclerosis in low-density lipoprotein<br />

receptor-deficient mice<br />

Fang Wang, PhD 1 • Zun Liu, PhD 1 • Se-Hyung Park, PhD 1 • Taesik Gwag, PhD 1 • Weiwei Lu, PhD 1 •<br />

Yipeng Sui, PhD 1 • Changcheng Zhou, PhD 1<br />

1Pharmacology and Nutritional Science, University of Kentucky<br />

Postdoc<br />

Objective: The Wnt/β-catenin signaling pathway is an ancient and evolutionarily conserved<br />

pathway regulating essential aspects of cell fate determination, proliferation, migration and<br />

polarity. Canonical Wnt/β-catenin signaling has been implicated in atherosclerosis development<br />

but the cell-specific role of β-catenin in atherogenesis remains elusive. Macrophage is one of the<br />

major cell types involved in the initiation and progression of atherosclerosis, and this study aims to<br />

investigate the impact of β-catenin expression on macrophage functions and atherosclerosis<br />

development.<br />

Methods and Results: To investigate the role of macrophage Wnt/β-catenin signaling in<br />

atherogenesis, we generated myeloid-specific β-catenin-deficient low-density lipoprotein receptordeficient<br />

mice (β-catenin∆myeLDLR-/-). As expected, deletion of β-catenin decreased macrophage<br />

adhesion and migration in vitro. However, β-catenin∆myeLDLR-/- mice had significantly increased<br />

atherosclerosis as compared with control littermates. Mechanistic studies revealed that β-catenin<br />

can directly regulate signal transducer and activator of transcription (STAT) pathway in<br />

macrophages, and ablation of β-catenin resulted in STAT1 activation, leading to elevated<br />

macrophage inflammatory responses and increased atherosclerosis.<br />

Conclusions: This study demonstrates a critical role of myeloid β-catenin expression in<br />

atherosclerosis by modulating macrophage inflammatory responses.<br />

41


26<br />

Vascular inflammation induced expression of lipid phosphate phosphatase<br />

Kavya Balaji 1 • Patrick Van Hoose, PhD 1 • Andrew Morris, PhD 1 • Susan Smyth, MD, PhD 1<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Undergraduate<br />

Lipid phosphate phosphatase 3 (PLPP3) is a polymorphic gene that is a member of the phosphatidic<br />

acid phosphatase family. It encodes for the cell surface enzyme, lipid phosphate phosphatase 3<br />

(LPP3) that regulates lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) availability<br />

and signaling. Genome wide association studies in humans identified heritable single nucleotide<br />

polymorphisms (SNPs) in PLPP3 that predicts coronary artery disease risk independently of<br />

traditional risk factors (odds ratio, 1.17; P=3.81×10–19). PLPP3 is dynamically regulated during<br />

vascular inflammation and the risk allele reduces gene expression by disrupting binding of CCAAT<br />

enhancer binding protein beta (CEBPβ). However, other mechanisms may control dynamic<br />

regulation of PLPP3. The USC Genome Browser identifies potential target sequences for NFκB<br />

responsive elements in the PLPP3 promoter, including three potential RelA (p65) binding sites.<br />

Hypothesis: These observations led to the hypothesis that angiotensin II, an inducer of vascular<br />

inflammation could regulate of PLPP3.<br />

Methods: Coronary human smooth muscle cells (caHSMCs) were treated for 12, 24, 48 and 72hrs<br />

hours with 1 M angiotensin II (ATII) in the presence or absence of parthenolide. Following<br />

treatment PLPP3 and p65 gene expression was examined.<br />

Results: The time course treatment of ATII revealed 72hr treatment upregulated PLPP3 gene<br />

expression in caHSMCs and this upregulation of PLPP3 was inhibited in the presence of<br />

parthenolide, an inhibitor of IκBα degradation.<br />

Conclusion: These observations suggest possible regulation of PLPP3 via an angiotensin II-NFkB<br />

dependent pathway, which may be important in the context of vascular disease.<br />

42


27<br />

LRP1 Deletion in Smooth Muscle Cells of the Outer Aortic Media Promotes Angiotensin IIinduced<br />

Thoracic Aortic Aneurysm<br />

Hisashi Sawada, MD, PhD 1 • Debra Rateri 1 • Mark Majesky, PhD 2 • Alan Daugherty, PhD 1<br />

1Saha CVRC, University of Kentucky • 2 Center for <strong>Cardiovascular</strong> Biology, University of Washington<br />

Postdoc<br />

Objective: Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional protein<br />

that is linked to several vascular pathologies. LRP1 deletion in smooth muscle cells (SMCs)<br />

accelerates angiotensin II (AngII)-induced thoracic aortic aneurysm (TAA). In association with TAA<br />

formation, there is medial thickening that is characterized by a transmural gradient in which<br />

pathology progressively increases from lumen to adventitial aspect. We hypothesized that deletion<br />

of LRP1 in the outer medial layers of the proximal thoracic aorta has a pivotal role in the<br />

pathogenesis of TAA. The aim of this study was to determine whether LRP1 deletion in the outer<br />

media accelerates AngII-induced TAA formation.<br />

Methods and Results: SMCs in the outer media of the ascending aorta are derived from the second<br />

heart field, as demonstrated by lineage tracing studies using Cre under the control of Mef2c.<br />

Therefore, we used Mef2c-driven Cre to delete LRP1 in SMCs of the outer medial layers. Female<br />

LRP1 flox/flox mice were bred to male Mef2c-Cre1/0 mice to generate study mice. We first<br />

confirmed LRP1 deletion in Cre1/0 mice by both immunostaining and Western blot. LRP1 was<br />

expressed ubiquitously across smooth muscle cells of all aortic medial layers in Cre 0/0 mice. In<br />

mice expressing Mef2c-Cre, aortic LRP1 protein was detected only in SMCs of the inner laminar<br />

medial layers. Western blotting demonstrated LRP1 protein abundance in Cre expressing mice was<br />

reduced by 43%. Saline or AngII (1,000 ng/kg/min) was infused by subcutaneous osmotic pumps<br />

for 28 days into 12 - 14 week-old male Cre0/0 and 1/0 mice. As expected, systolic blood pressure<br />

increased similarly in both AngII-infused Cre 0/0 and 1/0 mice compared to saline-infused mice.<br />

Aortic rupture occurred within 3 to 10 days after AngII infusion in 17% of AngII-infused Cre 0/0<br />

mice, while LRP1 deletion in Cre 1/0 mice increased aortic rupture to 27%. Aortic diameter in the<br />

survivors was significantly increased in Cre1/0 mice compared to Cre0/0 mice. Histologically,<br />

elastin fragmentation was detected in the aorta of AngII-infused Cre 0/0 mice and greater in Cre1/0<br />

mice.<br />

Conclusion: LRP1 in second heart field-derived SMCs of the outer media may play a critical role in<br />

the pathogenesis of TAA.<br />

43


28<br />

Sexual Dimorphism of Angiotensin II-induced Thoracic Aortic Rupture in Mice with LRP1<br />

Deficient Second Heart Field–derived Smooth Muscle Cells<br />

Bradley Wright 1 • Hisashi Sawada, MD, PhD 1 • Jessica Moorleghen 1 • Richard Charnigo, PhD 2 •<br />

Debra Rateri 1 • Mark Majesky, PhD 3 • Alan Daugherty, PhD 1<br />

1Saha CVRC, University of Kentucky • 2 Biostatistics, University of Kentucky • 3 Division of<br />

Cardiology, University of Washington<br />

Undergraduate<br />

Objective: Low-density lipoprotein receptor-related protein 1 (LRP1) maintains vascular<br />

homeostasis. Deletion of LRP1 in smooth muscle cells (SMCs) accelerates angiotensin II (AngII)-<br />

induced thoracic rupture and ascending aortic aneurysm. We demonstrated recently that SMCs in<br />

the outer medial layers of the ascending aorta were derived from second heart field (SHF). Deletion<br />

of LRP1 from SHF-SMCs significantly increased thoracic aortic rupture and aneurysms in male mice.<br />

The aim of this study was to determine if female sex influenced AngII-induced rupture and<br />

aneurysm in LRP1 deficient SHF-SMC mice.<br />

Methods and Results: Female LRP1 flox/flox mice were bred to male Mef2c-Cre 1/0 mice to<br />

generate study mice. Either saline or AngII (1,000 ng/kg/min) was infused by subcutaneous<br />

osmotic pumps for 28 days into 12-14 week old Cre 0/0 and Cre 1/0 mice of both sexes (N=12-31).<br />

As expected, AngII infusion increased systolic blood pressure in both sexes. During AngII infusion,<br />

aortic rupture occurred within 3 to10 days in 17% of Cre 0/0 mice, while LRP1 deletion in Cre 1/0<br />

mice increased significantly to 27% in males. Aortic rupture rate in AngII-infused female mice was<br />

decreased significantly compared to male mice, as there were none in Cre 0/0 and within 6-14 days<br />

only 9% in Cre 1/0 female mice. Ultrasonography was used to measure ascending aortic dilation as<br />

an index of thoracic aneurysm. Ascending aortic diameter in the survivors was significantly<br />

increased in AngII-infused Cre 1/0 vs Cre 0/0 and saline-infused controls in both sexes.<br />

Conclusion: Although male and female Cre1/0 mice experienced similar dilation of the ascending<br />

aorta under AngII infusion, female Cre1/0 mice experienced a significantly increased rate of<br />

survival compared to male litter mates. Future studies will determine the mechanism of sexual<br />

dimorphism that reduces AngII-induced thoracic aortic rupture in females.<br />

44


29<br />

SAA is not Just an HDL-Associated Lipoprotein<br />

Patricia Wilson, MS 1 • Joel Thompson, PhD 1 • Frederick de Beer, MD, PhD 1 • Nancy Webb, PhD 1 •<br />

Lisa Tannock, MD, PhD 2<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Endocrinology/Saha<br />

<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Staff<br />

<strong>Cardiovascular</strong> disease (CVD) is the leading cause of death in developed nations despite widespread<br />

use of pharmacological interventions. Individuals with obesity and/or diabetes are at particularly<br />

high risk for CVD and research suggests this may be due to elevated levels of serum amyloid A<br />

(SAA). Brief and chronic elevations of SAA have been indeed found to be atherogenic in mouse<br />

models. The current dogma is that SAA is exclusively an HDL associated lipoprotein. However, we<br />

and others have reported SAA on apoB-containing lipoproteins in both humans and mice and<br />

several studies have recently suggested that SAA-LDL is a risk factor for CVD. The goal of this study<br />

was to determine if SAA can shift between HDL and apoB-containing particles, and if the presence<br />

of SAA on apoB particles affects their atherogenicity. To determine if SAA could be exchanged<br />

between lipoproteins in vitro, we first incubated SAA with each lipoprotein separately, then mixed<br />

the lipoprotein containing SAA with each of the other two lipoproteins. To determine is this<br />

exchange could also occur in vivo, we injected apoE-/- x SAA1.1/2.1-DKO mice with murine SAA<br />

complexed with individual murine lipoproteins. To elucidate the role of CETP in SAA shifting, some<br />

mice were preinjected with an adenovirus expressing CETP 72 hours prior to injection with SAA-<br />

HDL. We now have evidence that SAA does indeed shift between lipoproteins both in vitro and in<br />

vivo, facilitated by CETP, and that delipidated SAA will completely associate with any available<br />

lipoproteins although preferentially on HDL. The presence of SAA on apoB-containing lipoproteins<br />

has physiological relevance, as we have demonstrated that this augments the proteoglycan binding<br />

affinity of these particles thus increasing their atherogencity. Collectively our data shows that SAA<br />

can be exchanged from HDL to apoB-containing lipoproteins and that this exchange is proatherogenic.<br />

45


30<br />

Computational modeling of amylin-induced calcium dysregulation in rat ventricular<br />

cardiomyocytes<br />

Peter Kekenes-Huskey 1<br />

1Chemistry, University of Kentucky<br />

Faculty<br />

Hyperamylinemia is a condition that accompanies obesity and precedes type II diabetes, and it is<br />

characterized by above-normal blood levels of amylin, the pancreas-derived peptide. Human amylin<br />

oligomerizes easily and can deposit in the pancreas [1], brain [2], and heart [3], where they have<br />

been associated with calcium dysregulation. In the heart, accumulating evidence<br />

suggests that human amylin oligomers form moderately cation-selective [4, 5] channels that embed<br />

in the cell sarcolemma (SL). The oligomers increase membrane conductance in a concentrationdependent<br />

manner [5], which is correlated with elevated cytosolic Ca 2+ . These findings motivate<br />

our core hypothesis that non-selective inward Ca 2+ conduction afforded by human amylin<br />

oligomers increase cytosolic and SR Ca 2+ load, which thereby magnifies intracellular Ca 2+<br />

transients. Questions remain however regarding the mechanism of amylin-induced Ca 2+<br />

dysregulation, including whether enhanced SL Ca 2+ influx is sufficient to elevate cytosolic Ca 2+<br />

load [6], and if so, how might amplified Ca 2+ transients perturb Ca 2+ -dependent cardiac<br />

pathways. To investigate these questions, we modified a computational model of cardiomyocytes Ca<br />

2+ signaling to reflect experimentally-measured changes in SL membrane permeation and<br />

decreased sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) function stemming from<br />

acute and transgenic human amylin peptide exposure. With this model, we confirmed the<br />

hypothesis that increasing SL permeation alone was sufficient to enhance Ca 2+ transient<br />

amplitudes. Our model indicated that amplified cytosolic transients are driven by increased Ca 2+<br />

loading of the sarcoplasmic reticulum (SR) and the greater fractional release may contribute to the<br />

Ca 2+ -dependent activation of calmodulin. Importantly, elevated Ca 2+ in the SR and dyadic space<br />

collectively drive greater fractional SR Ca 2+ release for human amylin expressing rats (HIP) and<br />

acute amylin-exposed rats (+Amylin) mice, which contributes to the inotropic rise in cytosolic Ca 2+<br />

transients. These findings suggest that increased membrane permeation induced by<br />

oligomeratization of amylin peptide in cell sarcolemma contributes to Ca 2+ dysregulation in prediabetes.<br />

46


31<br />

PCB 126 Disrupts Gut Microbiota and Increases Intestinal Inflammation in a Mouse Model of<br />

Atherosclerosis<br />

Jessie Hoffman, MS 1 • Michael Petriello, PhD 2 • Olga Vsevolozhskaya, PhD 3 •<br />

Richard Charningo, PhD 3 • Andrew Morris, PhD 2 • Bernhard Hennig, PhD 4<br />

1Pharmacology and Nutritional Sciences, University of Kentucky • 2 Division of <strong>Cardiovascular</strong><br />

Medicine, University of Kentucky • 3 Biostatistics, University of Kentucky • 4 Animal and Food<br />

Sciences, University of Kentucky<br />

Graduate Student<br />

The gut microbiome is sensitive to diet and environmental factors and is involved in the regulation<br />

of many host metabolic responses. Dioxin-like pollutants contaminate many food sources, and thus<br />

human exposure begins within the gut, which may play a role in pollutant-induced systemic<br />

toxicity. Additionally, gut dysbiosis and inflammation pose risk factors for the development of<br />

cardiovascular diseases, specifically atherosclerosis. We hypothesize that the dioxin-like pollutant<br />

PCB 126 will perturb gut microbial populations and impair gut health, which may contribute to<br />

pollutant-induced systemic toxicity in an atherosclerotic mouse model. LDLr -/- mice were fed a<br />

low fat atherogenic diet (10% fat, 0.15% cholesterol) for 14 weeks and exposed to PCB 126 at week<br />

2 and 4. Exposure to PCB 126 reduced gut microbial diversity and shifted populations at the<br />

phylum and genus levels in ways that mimic observations in chronic inflammatory diseases.<br />

Furthermore, PCB exposed mice exhibited increased markers of inflammation in intestinal and<br />

plasma samples. Interestingly, Cyp1a1 gene expression was increased in intestinal samples even 10<br />

weeks after PCB exposure, indicating a slow continual passage of pollutants through the<br />

enterohepatic circulation. These data imply that PCB toxicity is already initiated in the gut through<br />

disruption of healthy microbiota, and increases in gut inflammation. These observations highlight a<br />

unique opportunity for dietary interventions that are beneficial for both gut and overall health.<br />

Further research should examine how nutritional components can combat pollutant induced<br />

toxicity initiated at the gut level.<br />

47


32<br />

PCB 126 Exposure Increases Peripheral Vascular Disease Risk in Mice with Fatty Liver<br />

Jazmyne Barney 1 • Banrida Wahlang, PhD 2 • Brendan Thompson 1 • Chunyan Wang, PhD 3 •<br />

Omer Hamad 3 • Jessie Hoffman, MS 4 • Michael Petriello, PhD 2 • Andrew Morris, PhD 2 •<br />

Bernhard Hennig, PhD 3<br />

1Toxicology and Cancer Biology, University of Kentucky • 2 UK Superfund <strong>Research</strong> Center,<br />

University of Kentucky • 3 Animal and Food Sciences, University of Kentucky • 4 Pharmacology and<br />

Nutritional Sciences, University of Kentucky<br />

Graduate Student<br />

Xenobiotic and energy metabolism is dependent on a functional liver. Exposure to environmental<br />

pollutants like polychlorinated biphenyls (PCBs) is associated with inflammatory diseases,<br />

including non-alcoholic fatty liver disease and atherosclerosis. A compromised liver may play a<br />

critical role in modifying the induction of PCB toxicity and inflammation of the peripheral<br />

vasculature. Over a 14 week study, male C57Bl/6 mice (n=10) were fed an amino acid control diet<br />

or a methionine-choline deficient diet (MCD) with or without oral gavage of PCB 126 (0.5mg/kg).<br />

Post euthanasia, tissue and blood were collected for histological, toxicological, and inflammatory<br />

evaluation. Regardless of diet, PCB 126 induced hepatic steatosis. The MCD+PCB126 group<br />

exhibited fibrosis and increased liver to body weight ratio, suggesting liver injury and toxicity. Mice<br />

fed MCD-diet and exposed to PCB 126 demonstrated altered expression of hepatic genes involved in<br />

carbohydrate and lipid metabolism, indicating metabolic dysfunction. With regard to effects of PCB<br />

126 on extra-hepatic organs, all mice fed MCD diet had decreased expression of plasma leptin and<br />

resistin, and PCB 126 exposed groups appeared to have crown like structures in their epididymal<br />

adipose tissue, indicating the presence of inflammatory cells. In addition, MCD+PCB 126 mice<br />

displayed increased plasma inflammatory markers including Icam-1, Mcp-1, and Tnf-α.<br />

Interestingly, in the MCD+PCB 126 group, plasma ALT and AST levels were increased as well as proatherogenic<br />

trimethylamine-N-oxide (TMAO), implying simultaneous liver damage and increased<br />

peripheral vasculature disease risk. Together these results provide a novel linkage of a<br />

compromised liver to PCB-induced hepatic and vascular inflammation. These finding also a have<br />

translational component, suggesting environmental pollutants can cause inflammatory disease<br />

pathologies by stimulating cross-talk between individual organ systems. (Supported in part by<br />

NIEHS/NIH grant P42ES007380).<br />

48


33<br />

Promoter Enhancer Interactions Regulating PLPP3 Gene Expression<br />

Guogen Mao, PhD 1 • Shaojing Ye, PhD 1 • Susan S. Smyth, MD, PhD 2 • Andrew J. Morris, PhD 2<br />

1Gill Heart and Vascular Institute, University of Kentucky • 2 Gill Heart and Vascular Institute,<br />

Veterans Affairs Medical Center,, University of Kentucky<br />

Staff<br />

Common heritable intronic variants within the final fifth intron of the PLPP3 gene associate with<br />

significant inter individual differences in human coronary artery disease risk. PLPP3 is one of three<br />

closely related genes encoding lipid phosphate phosphatases 1-3 which are integral membrane<br />

enzymes that dephosphorylate lipid phosphate mono esters and some lipid polyphosphates. PLPP3<br />

expression in vascular endothelial cells is required for mouse development and while individuals<br />

with heterozygosity for loss of function PLPP3 alleles have been identified homozygotes have not so<br />

PLPP3 is likely also essential for human development. Because the three PLPP genes have<br />

overlapping expression patterns and encode enzymes with very similar activities it is reasonable to<br />

hypothesize that differences in regulation of expression may underlie these unique functions of<br />

PLPP3 gene in atherosclerosis and development. We used informatic approaches to identify<br />

regulatory elements within the PLPP3 promoter and coronary artery disease risk haplotype block.<br />

We then cloned the relevant sequences into reporter constructs and used transfection assays and<br />

site directed mutagenesis to examine sequence and allele specific effects on promoter and enhancer<br />

activity and on how these interact to control gene expression. The ~1.5 KB PLPP3 promoter<br />

comprises a ~0.5 KB enhancer indicated by H3K4ms1/H3K27Ac markers and a ~1KB core<br />

promoter containing three NF-kB (p50/RelA and p42/RelB) binding sites. Chromatin<br />

immunoprecipitation and reporter assays indicate that all three of these are functional regulators of<br />

basal activity of the PLPP3 promoter with very strong upregulation of promoter activity observed<br />

in transfection assays with these transcription factors. Similar informatic approaches identified<br />

cFOS and C/EBP target sequences in accessible chromatin within the coronary artery disease risk<br />

associated haplotype block in the final intron of the PLPP3 gene. These sequences are conserved in<br />

mice and humans and interact with their cognate transcription factors in immunoprecipitation and<br />

gel shift assays and regulate expression of both generic promoters and the PLPP3 promoter in<br />

reporter gene/transfection assays. The cFOS and C/EBP target sequences exhibit allelic variation in<br />

humans with coronary artery disease risk variants decreasing transcription factor binding and<br />

transcriptional enhancer activity. Taken together these results identify an NF-kB driven pathway<br />

that likely explains the widely observed strong upregulation of PLPP3 expression during<br />

inflammation and atherosclerosis and suggest a mechanism by which coronary artery disease risk<br />

associated variants of intronic enhancer sequences could decrease PLPP3 expression and reduce<br />

the normally protective functions of this gene observed in experimental models of atherosclerosis.<br />

49


34<br />

Endothelial Mineralocorticoid Receptor and Neutrophils Mediate Aldo plus Salt-Induced<br />

Abdominal Aortic Aneurysm<br />

Shu Liu 1 • Yu Zhong 1 • Zhenheng Guo 2 • Ming Gong 1<br />

1Physiology, University of Kentucky • 2 Pharmacology and Nutritional Sciences, University of<br />

Kentucky<br />

Staff<br />

<strong>Abstract</strong><br />

Objective—We recently reported that administration of mice with aldosterone (Aldo) or<br />

deoxycorticosterone acetate (DOCA) plus salt induces AAA via mineralocorticoid receptor (MR).<br />

The current study defines the specific roles of endothelial and myeloid cell MR in DOCA-salt<br />

induced AAA.<br />

Approach and Results—A tamoxifen inducible endothelial cell (EC)-specific MR knockout mouse<br />

model (iECMRKO) and a myeloid cell-specific MR knockout mouse model (MyMRKO) were<br />

developed. The iECMRKO mice, but not the MyMRKO mice were protected from Aldo- or DOCA-saltinduced<br />

AAA. Mechanistically, EC-specific MR deletion had little effect on Aldo-salt-induced salt<br />

retention, hypertension, and renal fibrosis, but largely suppressed aortic elastin degradation,<br />

matrix metalloproteinase-2 (MMP-2) and MMP-9 upregulation, macrophage and neutrophil<br />

infiltration. Surprisingly, neutrophils, but not macrophages, were observed in the aorta 1 week<br />

after Aldo-salt administration in control mice, but not in iECMRKO mice. Treatment of C57BL/6<br />

mice with an anti-PMN antibody selectively suppressed Aldo-salt-induced circulating Ly6G-postive<br />

neutrophils, but not CD4-postive leukocytes, and protected mice from Aldo-salt-induced AAA. In<br />

cell cultures, Aldo-induced endothelial adhesion molecules (E-selectin, P-selectin, and ICAM-1, but<br />

not VCAM-1) and proinflammatory cytokine (IL-6 and MCP-1) mRNA expressions were abolished in<br />

MR-deficient ECs. Importantly, Aldo-salt-induced ICAM-1 but not VCAM-1 protein upregulation was<br />

abolished in aortas from iECMRKO mice.<br />

Conclusions—Endothelial MR, but not myeloid cell MR, plays an important role in Aldo-salt-induced<br />

AAA. Moreover, ICAM-1, but not VCAM-1; and neutrophils, but not macrophages, mediate the early<br />

processes of Aldo-salt-induced and endothelial MR-mediated AAA development.<br />

50


35<br />

Identification of Candidate Long QT Syndrome Type 2 Patients Starting from Exome<br />

Sequences Identified in a Biobank Cohort<br />

Allison Hall, MS 1 • Don Burgess, PhD 2 • Pierre Fwelo 1 • Jennifer Smith 3 • Corey Anderson, PhD 4 •<br />

Craig T. January, MD, PhD 4 • Ann Stepanchick, PhD 4 • Uyenlinh Mirshah, PhD 4 • Jonathan Luo, PhD 4<br />

• Dustin Hartzel, PhD 4 • Michael Murray, MD 5 • Tooraj Mirshahi, PhD 5 • Brian Delisle, PhD 1<br />

1Physiology, University of Kentucky • 2 Physics, Asbury • 3 University of Kentucky • 4 University of<br />

Wisconsin • 5 Geisinger Health System<br />

Staff<br />

Introduction: Every year congenital long QT syndrome (LQTS) is thought to cause sudden cardiac<br />

death in hundreds of individuals in the US. Genetic screening potentially could identify LQTS<br />

patients before it strikes. However, genetic analyses often find novel rare sequence variants of<br />

uncertain physiological significance, and little is known about genetic screening in unaffected<br />

populations.<br />

Hypothesis: LQTS type 2 (LQT2) is caused by loss-of-function mutations in the rapidly activating<br />

delayed rectifier K+ channel gene KCNH2 (Kv11.1). Screening for KCNH2 variants using an<br />

approach similar to the Comprehensive In Vitro Proarrhythmia Assay for drug testing will allow the<br />

identification of candidate LQT2 patients starting from exome sequences.<br />

Methods: Ten KCNH2 mutations from the NCBI ClinVar database listed as “pathogenic”, “suspectedpathogenic”,<br />

or “conflicting interpretations” were identified in 10,000 Whole Exome Sequences<br />

(WES) from the Geisinger MyCode® cohort. The KCNH2 mutations were screened using Western<br />

blot to quantify terminally glycosylated mature Kv11.1 protein (a proxy for Kv11.1 channel<br />

trafficking); patch-clamp to measure Kv11.1 channel current (IKv11.1); and computational<br />

simulations with a human ventricular action potential (AP) model to predict AP duration (a<br />

correlate for the QT interval).<br />

Results: Two of the KCNH2 mutations were trafficking-deficient to decrease mature Kv11.1 protein<br />

and peak IKv11.1, and five mutations altered normal Kv11.1 channel activation or deactivation.<br />

Simulating the decrease in IKv11.1 caused by the trafficking-deficient KCNH2 mutations increased<br />

AP duration by >30%, whereas the mutations that disrupted Kv11.1 channel gating did not predict<br />

significant changes in AP duration. De-identified Electronic Health Records (EHR) from the<br />

Geisinger MyCode® subjects showed that the corrected QT interval (QTc Bazette) for the patients<br />

that harbored the trafficking-deficient KCNH2 mutations was ≥480 ms, whereas the average QTc<br />

for all EHR database subjects was


36<br />

Optimization of immunomagnetic separation for cryopreserved cord blood and apheresis<br />

mononuclear cell fractions derived endothelial progenitor cells<br />

Himi Tripathi, PhD 1 • Lakshman Chelvarajan, PhD 1 • Brad J Berron, PhD 2 • Ahmed Abdel Latif, MD,<br />

PhD 1<br />

1Gill Heart Institute and Division of <strong>Cardiovascular</strong> Medicine, University of Kentucky • 2 Department<br />

of Chemical and Materials Engineering, University of Kentucky<br />

Staff<br />

Introduction: <strong>Cardiovascular</strong> tissue damage in acute myocardial infarction mainly arises from the<br />

loss of blood flow, leading to changes in the composition and function of the ischemic region and<br />

heat failure. Multiple studies have examined the utility of CD34+ endothelial progenitor cells (EPCs)<br />

for limiting tissue damage and promoting tissue repair after an ischemic event. However, isolation<br />

of EPCs using traditional fluorescent activated cell sorting is cumbersome, expensive and time<br />

consuming. In this study, we examined the efficacy of novel antigen based methods for EPC<br />

isolation from human cord blood.<br />

Methods and Results: Immunomagnetic cell sorting protocol to purify CD34+ cells from<br />

cryopreserved cord blood and apheresis samples was optimized using MACS ultrapure CD 34<br />

microbead kit. Cell viability, CD 34 purity and endothelial progenitor cells phenotypic expression<br />

was assessed using flow cytometer and trypan blue assay. After thawing cryopreserved cord blood,<br />

we observed >80 ± 10% viable cells and 95±5% viable apheresis cells. CD34+ purity of 74 ± 16%<br />

and 94 ± 1.7% was achieved in cryopreserved cord blood and apheresis samples, respectively.<br />

Recovery of CD34+ cells was higher from apheresis (64.6%) in comparison to cord blood (31.3%).<br />

Post selection, the expression of EPCs markers was 65.6± 23.2 for CD31 and 90.3 ± 6.6 for CD133 in<br />

cord blood and 79.7± 5.5 and 69.6 ± 5.4 in apheresis samples. Additionally, we observed<br />

significantly higher recovery and system efficiency when using small input number of CD34+ cells<br />

(3.02 ± 2.7 X 106 vs. 31.3% ±54.1 X 106; p


37<br />

Elevated circulating TGF-beta is not the cause of increased atherosclerosis development in<br />

biglycan deficient mice<br />

Joel Thompson, PhD 1 • Patricia Wilson, PhD 1 • Alex Wyllie 1 • Adrian Wyllie 1 • Lisa Tannock, MD 1<br />

1Internal Medicine, University of Kentucky<br />

Staff<br />

Background: Vascular biglycan contributes to atherosclerosis development and increased biglycan<br />

expression correlates with increased atherosclerosis. However, mice deficient in biglycan have<br />

either no reduction in atherosclerosis or an unexpected increase in atherosclerosis. Biglycan<br />

deficient mice have systemically elevated TGF-beta, likely due to lack of sequestration of TGF-beta<br />

in extracellular matrix The purpose of this study was to determine if prevention of TGF-beta<br />

elevations in biglycan deficient mice affected atherosclerosis development.<br />

Methods: Biglycan deficient mice were crossed to Ldlr deficient mice. Diabetes was induced via<br />

streptozotocin and all mice were fed a high cholesterol diet. Diabetic biglycan wildtype and biglycan<br />

deficient Ldlr deficient mice were injected with the TGF-beta neutralizing antibody 1D11 or<br />

irrelevant control antibody 13C4.<br />

Results: Biglycan deficient mice had significantly elevated plasma TGF-beta levels, which was<br />

further increased by diabetes, and significantly increased atherosclerosis. There was a significant<br />

correlation between TGF-beta concentrations and atherosclerosis. However, despite nearly<br />

complete suppression of plasma TGF-beta levels in mice treated with the TGF-beta neutralizing<br />

antibody 1D11, there was no significant difference in atherosclerosis between mice with elevated<br />

TGF-beta levels and mice with suppressed TGF-beta levels.<br />

Conclusions: The increased atherosclerosis in biglycan deficient mice does not appear to be due to<br />

elevations in TGF-beta.<br />

53


38<br />

Gestational Diabetes Provokes Postpartum Cardiac Hypertrophy via Activation of Ca2+-<br />

Dependent Signaling<br />

Amanda Hoskins 2 • Nirmal Verma, PhD 1 • Florin Despa, PhD 1 • Sanda Despa, PhD 1<br />

1Pharmacology & Nutritional Sciences, University of Kentucky • 2 University of Kentucky<br />

Undergraduate<br />

Introduction: Gestational diabetes mellitus (GDM) complicates 9% of pregnancies in the US and its<br />

incidence is growing. Women with prior GDM have higher risk of developing cardiac hypertrophy<br />

and dysfunction, but the underlying mechanisms are largely unknown.<br />

Hypothesis: GDM promotes pathological growth of the heart through Ca2+-dependent hypertrophy<br />

signaling.<br />

Methods and Results: Female rats that express the human isoform of amylin, an amyloidogenic<br />

peptide co-secreted with insulin, in the pancreatic β-cells (HIP rats) were used as a GDM model. WT<br />

littermates served as controls. In both groups, glucose tolerance decreased during pregnancy and<br />

recovered after giving birth, with HIP females remaining glucose intolerant compared to the WT<br />

throughout the study. Cardiac hypertrophy, assessed from heart weight-to-body weight ratio, heart<br />

weight-to-tibia length ratio and echocardiographic measurements of the left-ventricular wall,<br />

occurred in both HIP and WT females during pregnancy. By two months postpartum, heart size<br />

returned to the pre-pregnancy level in the WT but remained significantly larger in HIP females. To<br />

uncover the cause of hypertrophy in postpartum HIP females, we investigated the activation status<br />

of calcineurin/NFAT and CaMKII/HDAC hypertrophy pathways. Calcineurin/NFAT signaling,<br />

assessed from the nuclear-to-cytosolic localization of NFATc4, was reduced during late pregnancy<br />

in both groups. In WT females, this pathway returned to its baseline activation level within two<br />

months postpartum. However, in postpartum HIP females the ratio of nuclear-to-cytosolic NFATc4<br />

was significantly larger than at baseline, indicating re-activation of this hypertrophy pathway. In<br />

contrast, the CaMKII/HDAC hypertrophy signaling was strongly activated in late pregnancy and<br />

returned to baseline postpartum in both HIP and WT females. Since calcineurin and CaMKII are<br />

activated by higher cytosolic Ca2+, we also analyzed myocyte Ca2+ cycling. Ca2+ transient decay<br />

was slower in myocytes from postpartum HIP females vs. baseline, while no differences occurred in<br />

the WT.<br />

Conclusion: Two months after a GDM-complicated pregnancy, female rats show cardiac<br />

hypertrophy that is likely caused by activation of calcineurin/NFAT hypertrophy pathway.<br />

54


39<br />

Effects of Molecular Clock Component Deletion in Mouse Cardiomyocytes on Long QT<br />

Syndrome Phenotype<br />

Kaitlyn Samuels 1 • Elizabeth Schroder 1 • Tanya Seward 1 • Brian Delisle, PhD 1<br />

1Physiology, University of Kentucky<br />

Undergraduate<br />

Cardiac excitability is affected by various genetic and environmental perturbations, which is often<br />

the cause of a multitude of human cardiac diseases. Specifically, this study explored the effects of<br />

the genetic knockout of the Bmal1 circadian transcription factor in mouse heart cells superimposed<br />

upon a congenital Scn5a sodium ion channel genetic mutation representative of long QT syndrome<br />

type 3 (LQT3) in humans. Changes in electrocardiographic (ECG) properties were evaluated to<br />

investigate the changes in cardiac excitability in these transgenic mice. There were a significantly<br />

higher number of cardiac arrhythmias after the Bmal1 gene knockout than before the knockout,<br />

specifically an increased number of RR-interval pauses. There was also a consistently slower heart<br />

rate after the Bmal1 gene knockout. Finally, there was increased slope factor between the RRinterval<br />

and QT-interval after the Bmal1 knockout than before the knockout. These findings are<br />

consistent with previous similar investigations and serve to help provide a better understanding of<br />

the pathophysiology associated with cardiac genetic mutations.<br />

55


40<br />

The Prognostic Role of Elevated Myeloperoxidase in Patients with Acute Coronary<br />

Syndrome: A Systematic Review and Meta-Analysis<br />

Mohamed Abo-Aly, MD 1 • Andrew kolodziej, MD 1 • Raphael Twerenbold, MD 1 •<br />

Christian Mueller, MD 1 • Ahmed Abdel-Latif, MD, PhD 1<br />

1Division of cardiovascular medicine, Gill heart institution., University of Kentucky<br />

Postdoc<br />

Background:<br />

Many reports have shown the correlation between myeloperoxidase (MPO) and the pathogenesis of<br />

acute coronary syndrome (ACS). However, the prognostic role of MPO for major cardiac events or<br />

mortality in ACS patients has not been well studied. We sought to perform a systematic review and<br />

meta-analysis to examine the prognostic value of inpatient MPO level in patients presenting with<br />

ACS.<br />

Methods:<br />

PubMed and Cochrane databases were searched from 1975 to September <strong>2017</strong> for studies that<br />

investigated the prognostic value of serum MPO in patients with ACS. Studies should have<br />

dichotomized patients into a high MPO and a low MPO group, reported clinical outcomes according<br />

to the same cutoff value of MPO and followed up patients for at least 30 days to be eligible for<br />

enrollment. Data were analyzed using random-effects model to control heterogeneous reporting.<br />

Results:<br />

We retrieved 3896 studies for initial screening which yielded 14 studies including 9268 subjects<br />

with a median follow up of 8.7 ± 21.96 months for the final analysis. High serum MPO level<br />

significantly predicts the future risk of mortality (odds ratio [OR] 2.039; 95% confidence interval<br />

[CI]: 1.405-2.959; P=0.0176) and MACE (OR 1.42; 95% CI: 1.00-1.99; p=0.044). we also observed a<br />

string trend towards higher incidence of recurrent myocardial infarction (MI) in patients with high<br />

MPO level (OR 1.24; 95% CI: 0.99-1.54; p=0.054) in comparison to patients with low serum MPO.<br />

Conclusion:<br />

In this meta-analysis examining the long outcomes in ACS patients, high MPO levels were associated<br />

with worse clinical outcomes. These observations support the use of MPO as a novel clinical<br />

prognostic marker in patients with acute coronary syndrome.<br />

56


41<br />

Desynchrony of Tissue Oscillators and Compromised Blood Pressure Circadian Rhythm in a<br />

Novel Diabetic Db/Db-Mper2luc Mouse Model<br />

Tianfei Hou, MS 1 • Wen Su, MD 1 • Ming Gong, MD, PhD 2 • Zhenheng Guo, PhD 1<br />

1Department of Pharmacology and Nutritional Sciences, University of Kentucky • 2 Department of<br />

Physiology, University of Kentucky<br />

Graduate Student<br />

Diabetic patients have a high prevalence of blood pressure (BP) circadian rhythm disruption mostly<br />

manifested as reduced BP dipping during the inactive phase (non-dipping profile). Accumulating<br />

evidence demonstrates a pathophysiological link between end-organ damage and non-dipping BP.<br />

Clock gene dysregulation may link diabetes with non-dipping BP but comprehensive study of clock<br />

gene oscillation dysregulation in diabetes has been hampered by the impractical requirement of<br />

intensive timed sampling. To address this issue, we generated a novel diabetic model, db/dbmPer2Luc<br />

mouse, by crossing the extensively used type 2 diabetic db/db mice with the clock gene<br />

Period 2 (mPer2) luciferase knock-in mPer2Luc mice. The db/db-mPer2Luc mice were obese,<br />

diabetic and had non-dipping BP. Real-time measurement of bioluminescence of the many tissues<br />

explanted from the db/db-mPer2Luc mice revealed that the phases of the mPer2 circadian<br />

oscillations shifted to different extents in aorta, mesenteric artery, kidney, liver, white adipose<br />

tissue and thymus, but no phase shift was detected in the central SCN tissue, or the adrenal gland<br />

and lung. The desynchrony of the tissue oscillators in the db/db-mPer2Luc mice was associated<br />

with compromised circadian rhythms in respiratory exchange ratio. Moreover, the time-of-day<br />

variations in vascular contractile responses and in baroreflex sensitivity were abolished. Taken<br />

together, we generated a novel diabetic db/db-mPer2Luc mouse model. Using this model, we<br />

revealed a desynchrony among tissue oscillators, a loss of the time-of-day variations in vascular<br />

contractile responses and baroreflex sensitivities, all of which likely contribute to the dampening of<br />

BP circadian rhythm in diabetes.<br />

57


42<br />

Lysophosphatidic Acid Receptor 4 Influence The development of Atherosclerotic Vascular<br />

Disease in Mouse Model<br />

Liping Yang, MD 1 • Andrew Morris, PhD 1 • Susan Smyth, MD, PhD 1<br />

1Internal Medicine - Cardiology, University of Kentucky<br />

Staff<br />

Background: Lysophosphatidic acid (LPA) is one of the simplest phospholipid signaling molecules.<br />

LPA elicits diverse biological functions including cell proliferation, differentiation, migration,<br />

survival and apoptosis through binding and activating specific cell surface G-protein coupled<br />

receptors (LPA1-6). LPA1/Edg2, LPA2/Edg4 and LPA3/Edg7 receptors are the endothelial<br />

differentiation gene (Edg) family. LPA4/p2y9/GPR23 of the purinergic receptor family and the<br />

related LPA5/GPR92 and LPA6/p2y5 have been identified as novel LPA receptors. LPA is generated<br />

by the secreted lysophospholipase D autotaxin (ATX) and inactivated by dephosphorylation by<br />

membrane lipid phosphate phosphatases (LPPs). Our previous work established that ATX and LPP3<br />

contribute to atherosclerotic vascular disease, but little is known about the role of specific LPA4<br />

receptors in atherosclerosis. We recently demonstrated upregulation of LPA4 in SMC undergoing a<br />

switch to assume a foam-cell like phenotype. The present work therefore aims to elucidate an<br />

association between LPA4 and experimental atherosclerosis in mice.<br />

Methods and Results: We generated mouse globally lacking LPA4 (LPA4-/-) on C57/BL background.<br />

Hyperlipidemia was elicited in the mice by PCSK9 virus injection at 5 weeks of age and then<br />

Western Diet feeding for 20 weeks. Although plasma cholesterol levels were similar, en face<br />

analysis of aortic atherosclerosis indicated a significant reduction in plaque area in LPA4-/-<br />

compared to LPA4-WT mice. Oil Red-O staining of aortic roots confirmed reduced neutral fat<br />

accumulation in the aortic roots of LPA4-/-mice. In sections taken at the level of the aortic root,<br />

CD68 and α-SMA immunoreactivity was lower in the absence of LPA4. SMCs isolated from mouse<br />

thoracic aorta were treated with ox-LDL to promote a foam cell phenotype, characterized by<br />

upregulation of CD68 expression. SMC isolated from LPA4-/- mice had lower CD68 mRNA after ox-<br />

LDL exposure than LPA4-WT cells.<br />

Conclusion: These findings revealed a role for LPA4 in vascular inflammation and the development<br />

of atherosclerotic vascular disease, potentially through effects of SMC phenotype and function.<br />

58


43<br />

Intracoronary Versus Intravenous Adenosine-Induced Maximal Hyperemia for Fractional<br />

Flow Reserve Measurement: A Systematic Review and Meta-Analysis<br />

Mohamed El-Helw, MD 1 • Mohamed Abo-Aly, MD 1 • Georges Lolay, MD 1 • Christopher Adams, MD 1 •<br />

Ahmed El-Sharaawy, MD 1 • Ahmed Abdel-Latif, MD, PhD 1 • Khaled Ziada, MD 1<br />

1Division of <strong>Cardiovascular</strong> Medicine, Gill Heart Institute, University of Kentucky<br />

Postdoc<br />

Background: Measurement of fractional flow reserve (FFR) is considered the gold standard<br />

technique for the invasive hemodynamic assessment of borderline coronary artery stenosis.<br />

Currently, intravenous (IV) adenosine is the recommended approach; however intracoronary (IC)<br />

administration is widely used due to its convenience and lower cost. The correlation between IV<br />

and IC administration to assess coronary blood flow is not well studied.<br />

Objective: This systematic review and meta-analysis is conducted to review the available literature<br />

that compared FFR measurements using bolus IC vs. standard continuous IV of adenosine infusion<br />

for detection of significant coronary artery stenosis.<br />

Methods: We systematically searched MEDLINE, EMBASE, Google scholar and the Cochrane Central<br />

Register of Controlled Trials databases. We reviewed data pertaining to the used adenosine doses,<br />

side effects of each method of administration and FFR values. We performed statistical analyses<br />

examining the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and odds<br />

ratio in studies comparing bolus IC adenosine and continues IV adenosine infusion using random<br />

effects modelling.<br />

Results: We identified 8 studies addressing the primary review question. Compared to standard IV<br />

adenosine infusion, the overall sensitivity of IC adenosine is 0.843 (95% C.I. 0.701-0.925, P


44<br />

Recapitulating In Vivo Fibroblast Differentiation Using a Hydrogel Cell Culture System<br />

Demetria Fischesser 1 • Onur Kanisicak, PhD 1 • Mario Perera 2 • Neil Ayres, PhD 2 • Jeff<br />

D Molkentin, PhD 1<br />

1Molecular <strong>Cardiovascular</strong> Biology, Cincinnati Children's Hospital • 2 Chemistry, University of<br />

Cincinnati<br />

Graduate Student<br />

Cardiac fibroblasts are resident interstitial cells known to maintain the extracellular matrix (ECM)<br />

under normal physiological conditions through the secretion of collagens and other adherent<br />

proteins. During injury, these fibroblasts take on an activated, contractile state and deposit<br />

additional ECM proteins to contribute to scar formation. While this response is initially beneficial to<br />

prevent rupture and further injury, continuous scar development leads to fibrosis, pathological<br />

ventricular remodeling and dysfunction, and eventual organ failure. Though much has already been<br />

discovered about the importance of fibroblasts during development and injury response, there are<br />

still many aspects of their functions that remain unclear. In order to decipher these fibroblast<br />

functions, many in vitro systems have been used to easily manipulate fibroblasts while attempting<br />

to mimic in vivo conditions. However, most of these systems have used plastic or gelatin-coated<br />

plastic as the surface medium. These have proven to be much stiffer than physiological tissue and<br />

provide a static system inhospitable to the dynamic changes of the activating fibroblast. In order to<br />

mimic an adaptable in vivo environment for fibroblast culture, we have developed a new hydrogel<br />

technology to understand fibroblast behavior and differentiation. This technology utilizes gelatin<br />

norbornene and a thiol conjugated to a Reversible Addition-Fragmentation Chain Transfer (RAFT)<br />

polymer which can dynamically mimic the stiffness of both healthy and fibrotic tissue, thus allowing<br />

for seamless modeling of injury and disease in various tissues. Through morphology and<br />

differentiation studies, we have found that there is a significant difference between fibroblasts<br />

plated on plastic versus softer hydrogels which mimic in vivo conditions. Fibroblasts plated on<br />

plastic and stiffer surfaces become very large and flat, and express markers of differentiation, such<br />

as alpha-Smooth Muscle Actin (αSMA), within days of plating. On softer hydrogels, however, the<br />

fibroblasts remain small and eventually develop long stellate appendages. They produce αSMA<br />

much more slowly and at a much less robust level than on stiffer surfaces. The morphology and<br />

differentiation pattern seen on softer hydrogels is highly comparable to fibroblasts observed in<br />

vivo. We will use these initial findings to better understand the activation and differentiation of<br />

fibroblasts and how, in injury, they first inhibit tissue damage and later enhance it. In the future, we<br />

plan to manipulate this hydrogel system to intentionally change the stiffness of the surface on<br />

which fibroblasts have already been plated to determine if we can mimic disease states as well as<br />

reverse the fibroblast activation phenotype seen previously.<br />

60


45<br />

Determination of The Effects Of High Fat Feeding On Autotaxin Activity<br />

Esias Bedingar 1 • Frederick Onono, PhD 2<br />

1University of Kentucky • 2 Internal Medicine , College of Medicine<br />

Undergraduate<br />

Obesity is a major public health issue in the United States and is risk factor for several diseases such<br />

as coronary artery disease and certain types of cancers. Although the association between obesity<br />

and cardiovascular diseases is well known, the underlying molecular mechanisms are still unclear.<br />

One of the hypotheses proposed to explain the link between obesity and disease risk is that<br />

consumption of high fat diets or increased synthesis and storage of fats is associated with the<br />

production of bioactive lipids or lipid-derived molecules that promote disease. Lysophosphatidic<br />

acid (LPA) is a family of bioactive lysophospholipids well-recognized as an important signaling<br />

molecule acting primarily through actions at cell-surface G-protein coupled receptors. There are<br />

two major ways of LPA production. However, the enzyme responsible for making majority of the<br />

circulating LPA is autotaxin (ATX), a secreted phospholipase D. Autotaxin is strongly expressed in<br />

adipose tissue, thus synthesis of circulating LPA from dietary lipids could be further enhanced in<br />

obese individuals.<br />

In this study, we investigated the effects of fasting and high-fat feeding on the activity levels of ATX.<br />

Healthy volunteer subjects (n=11) were asked to fast overnight. In the morning, their blood was<br />

collected at t=0 for plasma preparation. Then, they were given a drink composed of boost protein<br />

shake and triglycerides and blood drawn at hourly intervals for up to 8 hours. Autotaxin activity<br />

was determined in the plasma using synthetic substrates. Preliminary results indicated that ATX<br />

activity is acutely sensitive to fasting and feeding, with the lowest activity observed following<br />

fasting and increasing with feeding of a high fat diet. To confirm the specificity of the ATX activity a<br />

novel inhibitor was used to inhibit ATX activity. Our findings indicate that ATX is dependent on the<br />

feeding status and is increased following feeding with a high fat diet. This study suggests the<br />

efficacy of ATX pharmacological inhibition could be enhanced if timed with the onset of feeding.<br />

61


46<br />

Sex-Specific Differences in Cardiac Fibrosis<br />

Gregory Milburn 1 • Autumn Conger 1 • Cheavar Blair, PhD 1 • Maya Guglin, MD 2 • Gretchen Wells, MD,<br />

PhD 2 • Rebekah Waikel, PhD 3 • Kenneth Campbell, PhD 1<br />

1Physiology, University of Kentucky • 2 <strong>Cardiovascular</strong> Medicine, University of Kentucky •<br />

3Biological Sciences, Eastern Kentucky University<br />

Undergraduate<br />

<strong>Cardiovascular</strong> disease is the leading causes of death in America, which prompted a concerted effort<br />

to better understand the causes and to develop innovative therapies. The etiology of heart disease<br />

is complex and depends on several factors such as age, race, and sex, but previous research<br />

conducted contains gaps, as it often did not look for difference between these groups. This study<br />

aims to fill one aspect of this research gap by examining sex-specific differences in cardiac fibrosis<br />

in failing and non-failing human hearts. Cardiac fibrosis is a result of cardiac remodeling and causes<br />

decreased heart function post cardiac damage. A previous study, conducted in our lab, used<br />

Nanostring analysis to examine sex-specific differences in the expression of genes related to<br />

fibrosis. The results of this study showed certain gene expressions were specific to sex or had an<br />

interaction between the sex and heart failure status. Several of these genes were regulators of<br />

collagen, a common type of cardiac fibrosis. We continued this study by quantifying collagen in<br />

human heart samples, collected from heart transplants and non-viable organ donors. These<br />

samples were stained using an established picrosirius red staining technique, turning the collagen<br />

tissue red and normal cardiac tissue yellow. These samples were then quantified using a k-means<br />

cluster, via a program written in lab, to eliminate any bias in determining red and yellow tissue. The<br />

results are pending as there are still samples left to be completed. We hope to continue pursuing<br />

this line of inquiry into sex-specific differences in heart disease by examining passive stiffness, of<br />

which collagen is a major component.<br />

62


47<br />

Dietary Effects on Lipoprotein-Associated Bioactive Mediators of Atherosclerosis<br />

Cody Sutphin 1 • Maria Kraemer, PhD 2 • Pan Deng, PhD 2 • Courtney Hammill, PhD 2 •<br />

Susan Smyth, MD, PhD 2 • Andrew Morris, PhD 2<br />

1Eastern Kentucky University • 2 <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Undergraduate<br />

Elevated circulating levels of atherogenic lipoproteins associate with increased risk of<br />

cardiovascular disease. Multiple lines of evidence implicate bioactive components of lipoprotein<br />

particles (such as oxidized phospholipids) as signaling molecules that provoke responses in blood<br />

and vascular cells that cause the development and progression of atherosclerosis. Studies from<br />

ourselves and others identify a role for the bioactive lipid mediator lysophosphatidic acid (LPA) as<br />

a proinflammatory atherogenic signal in preclinical models and clinical settings. LPA accumulates<br />

in atheromas, and mice lacking certain LPA receptors are protected from experimentally induced<br />

atherosclerosis while mice lacking the LPA degrading enzyme lipid phosphate phosphatase 3<br />

(LPP3) exhibit accelerated atherosclerosis. These findings may explain why coronary artery disease<br />

risk is elevated in individuals with common genetic polymorphisms that decrease LPP3 expression.<br />

We hypothesized that LPA associated with low-density lipoprotein particles is sensitive to diet and<br />

enhanced by genetic hyperlipidemia. Plasma LDL-associated lipid species were analyzed in WT and<br />

LDLr-/- mice that were on either control or western diet. Mouse plasma was fractionated by sizeexclusion<br />

chromatography using a calibrated Superose 6 column to separate lipoprotein species<br />

and then analyzed by targeted and untargeted HPLC coupled mass spectrometry to identify and<br />

quantitate LPA species, as well as other lipid-class species, that were altered in LDL-containing<br />

plasma fractions. We found that circulating levels of LPA are highly sensitive to high fat feeding in<br />

mice and that genetic manipulations that reduce lipoprotein clearance (Ldlr-/-) dramatically<br />

increase circulating levels of LDL-associated LPA while reducing albumin-associated LPA.<br />

Additionally, we identified unexpected increases in a broad range of atherogenic lipoprotein<br />

particle- associated lipid species when hyperlipidemic mice are put onto a western diet. These<br />

studies provide new insights into how diet could influence coronary artery disease risk by<br />

promoting increase in atherogenic lipoprotein associated LPA.<br />

63


48<br />

Ticagrelor Reduces Inflammation and Mortality in a Murine Model of Sepsis and Reduces<br />

Platelet-Leukocyte Aggregates and Inflammation In Pneumonia<br />

Travis Sexton, PhD 1 • Guoying Zhang, MD 1 • Tracy Macaulay, PharmD 2 • Leigh Ann Callahan, MD 3 •<br />

Richard Charnigo, PhD 4 • Olga Vsevolozhskaya, PhD 4 • Zhenyu Li, PhD 1 • Susan Smyth, MD, PhD 2<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Gill Heart and Vascular Institute,<br />

University of Kentucky • 3 Pulmonary, Critical Care & Sleep Medicine, University of Kentucky •<br />

4Statistics, University of Kentucky<br />

Staff<br />

Background: Sepsis is a life-threatening and dysregulated response to infection that leads to<br />

numerous complications and carries substantial risk of mortality. Pneumonia is one of the most<br />

common precipitators of sepsis. Despite advances in treatment for sepsis and pneumonia,<br />

significant improvements have not been realized and high rates of cardiovascular events remain an<br />

issue. Retrospective analysis of clinical studies suggest anti-platelet therapy may improve outcomes<br />

in patients with pneumonia and sepsis.<br />

Methods: We conducted a human study with pneumonia patients (XANTHIPPE) and a murine study<br />

using a sepsis model to determine the effect of ticagrelor on inflammation, thrombosis, and lung<br />

function.<br />

Results: Among subjects with pneumonia not taking a P2Y12 antagonist at baseline, ticagrelor<br />

lowered the percent of leukocytes with attached platelets 11.75% at 24 hours compared to a<br />

10.90% increase in placebo patients. Furthermore, ticagrelor lowered plasma IL-6 levels 83% at 24<br />

hours compared to minimal change with placebo. Ticagrelor had a transient effect on markers for<br />

NETosis showing a significant 60% spike in MPO-NE complexes at 24 hours followed by a return<br />

toward baseline at 48 hours while placebo had no significant effect. Lung function tests also<br />

numerically improved with ticagrelor, although statistical significance was not achieved. In the<br />

murine sepsis model, disruption of the P2Y12 receptor protected against inflammatory response,<br />

lung permeability, and mortality.<br />

Conclusions: Our findings indicate a mechanistic link between platelets, leukocytes, and lung injury<br />

in settings of pneumonia and sepsis and suggest possible therapeutic approaches to reduce<br />

complications of pneumonia.<br />

64


49<br />

Endocytosis Mediates Platelets' Responses to Viruses In The Vasculature<br />

Meenakshi Banerjee, PhD 1 • Sidney Whiteheart, PhD 1<br />

1Molecular and Cellular Biochemistry, University of Kentucky<br />

Postdoc<br />

Platelet endocytosis is essential for Fibrinogen (Fg) uptake, receptor trafficking of integrins<br />

(αIIbβ3, αvβ3) and other surface receptors. However, the mechanistic underpinnings of<br />

endocytosis, its importance in platelets, and the molecular machinery required and possible<br />

trafficking routes are understudied, in part due to a lack of viable experimental tools. Previously we<br />

showed the importance of ADP-ribosylation factor 6 (Arf6), which regulates αIIbβ3-mediated Fg<br />

uptake/storage and affects acute platelet functions e.g., clot retraction and spreading. To further<br />

identify elements of the platelet endocytic machinery, we examined the role of a vesicle-residing<br />

Soluble N-ethylmaleimide Factor Attachment Protein Receptor (v-SNARE) called<br />

Cellubrevin/Vesicle Associated Membrane Protein-3 (VAMP-3) in platelet function. VAMP-3 KO<br />

platelets have defective uptake and accumulation of Fg, which led to enhanced platelet spreading<br />

on Fg and faster clot retraction. Using both Arf6 KO and VAMP-3 KO mutants as tools to probe the<br />

importance of endocytosis in platelets, we posited that platelet endocytosis could potentially be<br />

critical for actively sensing pathogenic damage in the vascular microenvironments and allowing<br />

platelets to act as immune cells. Previous reports show that platelets do endocytose viruses such as<br />

HIV-1 but the molecular machinery is ill-defined. In nucleated cells, responses to HIV-1 are<br />

mediated by virus phagocytosis/endocytosis, degradation to release Toll-like Receptor ligands, and<br />

subsequent receptor activation. Is this process recapitulated in platelets? Here we show that<br />

platelets indeed use VAMP-3 and Arf6-dependent pathways to endocytose HIV-1 virions, degrade<br />

retroviral particles to release TLR ligands, which initiate platelet activation and secretion.<br />

Consequently, HIV-1 uptake and subsequent activation is abolished in VAMP-3 and Arf6 KO mice.<br />

Collectively, our studies shed light on how platelets act at the early stage of pathogen recognition<br />

and are able to process them to initiate an immune response.<br />

65


50<br />

Association between Plasma Cholesterol Levels and the Development of Xanthomas, Malaise,<br />

and Inappetance in Cynomlgus Monkeys<br />

Morgan Kelly 1 • Courtney Burkett 1 • Sierra Paxton 1 • Lei Cai 1 • Ryan Temel, PhD 1<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Undergraduate<br />

<strong>Cardiovascular</strong> disease is the leading cause of death in the United States. There is a positive<br />

correlation between coronary heart disease (CHD) and LDL cholesterol (LDL-C) levels. Statins are<br />

used to lower LDL-C and CHD risk but do not completely eliminate CHD events caused by<br />

atherosclerotic lesion rupture. Therefore, finding a therapy capable of regressing or stabilizing<br />

atherosclerotic lesions is a priority for academic and pharmaceutical researchers. By stimulating<br />

macrophage cholesterol efflux and promoting anti-inflammatory macrophage polarization,<br />

antagonism of microRNA-33a (miR-33a) in mice causes aortic atherosclerotic lesions to acquire a<br />

more stable composition. However, the preclinical mouse studies have limited translational value<br />

since mice do not develop coronary artery atherosclerosis and express only one of the two miR-33<br />

family members found in humans. In contrast, nonhuman primates (NHPs) have miR-33a and miR-<br />

33b and develop coronary artery atherosclerosis and thus are a good model to determine the<br />

therapeutic potential of miR-33 antagonism in humans. In order to determine whether miR-33a/b<br />

antagonism can regress or stabilize atherosclerotic lesions, 36 male cynomolgus monkeys were fed<br />

for 20 months a diet high in fat and cholesterol, which increased LDL-C and drove atherosclerosis<br />

formation. During this period, the animals developed xanthomas and callosities due to cholesterol<br />

deposition in the skin. In addition, some of the monkeys went through prolonged periods of malaise<br />

and inappetance. The objectives of this project were to review the veterinary records and<br />

determine 1) the number of days on atherogenic diet needed to first observe xanthomas and<br />

callosities and 2) the number of incidences of malaise and prolonged inappetance per monkey. This<br />

data was then correlated to the average total plasma cholesterol (TPC) concentration during the 20<br />

months on atherogenic diet. A statistically significant, negative correlation was observed between<br />

the number of days to initial callosity formation and TPC (p= 0.049 and = 0.19). There were no<br />

statistically significant correlations between TPC and the other clinical observations. We are in the<br />

process of data collection but hypothesize that coronary artery atherosclerotic lesion size will be<br />

greater in animals that went through periods of malaise and inappetance. In addition, we<br />

hypothesize that the days for xanthoma/callosity formation will be inversely associated with<br />

plaque size. This information may allow our lab to predict atherosclerosis severity in monkeys<br />

based upon clinical observations.<br />

66


51<br />

Circadian disruption and atherosclerosis in ApolipoproteinE-deficient mice<br />

Eric McGann 1 • Jeffery Chalfant, MS 1 • Deborah Howatt 2 • Julie Pendergast, PhD 1<br />

1Biology, University of Kentucky • 2 Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky<br />

Staff<br />

The circadian system is a network of molecular clocks located throughout the body. These clocks<br />

coordinate daily rhythms of behavior and physiology with environmental cycles. Shift work, which<br />

chronically disrupts circadian rhythms, increases the risk of developing cardiovascular diseases.<br />

The mechanisms by which this happens, however, are largely unknown. Our long-term goal is to<br />

determine how disruption of circadian rhythms causes cardiovascular disease. Atherosclerosis is<br />

the build-up of plaques in arteries and can lead to myocardial infarction and stroke. In this study,<br />

we sought to investigate whether circadian disruption accelerates atherosclerosis in mice. Wildtype<br />

mice do not develop atherosclerotic lesions. Therefore, we studied C57BL/6J ApolipoproteinEdeficient<br />

(ApoE-/-) mice because they spontaneously develop atherosclerotic lesions. We first<br />

characterized circadian rhythms in ApoE-/- mice. We found that circadian behavioral rhythms,<br />

including free-running periods of activity in constant darkness and constant light, phase angles of<br />

entrainment, and phase shifts to light pulses, were similar between wild-type and ApoE-/- mice.<br />

These data show that ApoE-/- mice had no deficits in their circadian behavior rhythms or light<br />

responsiveness. Next, we determined if molecular circadian rhythms in tissues were altered in<br />

ApoE-/- mice. We analyzed the expression of the circadian timekeeping protein, PERIOD2, in<br />

central and peripheral tissues using a luciferase reporter. We found that PERIOD2::LUCIFERASE<br />

rhythms in tissues were similar in wild-type and ApoE-/- mice. We next determined the effect of<br />

constant light on the development of atherosclerosis in ApoE-/- mice. After 3 months in constant<br />

light, locomotor activity was arrhythmic or the rhythm was severely disrupted. In addition,<br />

atherosclerotic lesion area was increased in ApoE-/- mice in constant light compared to those in<br />

control 12h light-12h dark condition. Together, these data demonstrate that ApoE-/- mice have<br />

normal circadian rhythms and chronic circadian disruption accelerates atherosclerosis in ApoE-/-<br />

mice.<br />

This study was funded by National Institutes of Health grant P20GM103527, the Gertude F. Ribble<br />

Trust, and the University of Kentucky.<br />

67


52<br />

Does Light Pollution Affect the Development of Atherosclerosis?<br />

Robert Wendroth 1 • Eric McGann 1 • Deborah Howatt 2 • Julie Pendergast, PhD 1<br />

1Department of Biology, University of Kentucky • 2 Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University<br />

of Kentucky<br />

Undergraduate<br />

Exposure to light at night has been steadily increasing since industrialization. Light at night comes<br />

from light bulbs, light pollution produced by cities, and more recently from the widespread use of<br />

personal electronics (smart phones, tablets, laptops) at night. Previous studies in outbred mice<br />

have shown that dim light at night (DLAN) disrupts circadian rhythms and increases body weight,<br />

but it is unknown whether DLAN affects the development of cardiovascular disease. In this project,<br />

we are testing the hypothesis that DLAN accelerates the development of atherosclerotic lesions in<br />

C57BL/6J Apolipoprotein E-deficient (ApoE-/-) mice. We single-housed male ApoE-/- mice in lighttight<br />

boxes at 7 weeks of age for 1 week in 12h light:12h dark (12L:12D) and then in DLAN (12h<br />

light: 12h dim 5 lux light) for 12 weeks. Control mice were maintained in 12L:12D for 13 weeks.<br />

Body weights did not differ between ApoE-/- mice in 12L:12D and DLAN. In 12L:12D, ApoE-/- mice<br />

had a robust rhythm of eating behavior that peaked during the night. However, after a few days in<br />

DLAN, ApoE-/- mice had a low-amplitude eating behavior rhythm. Preliminary data also suggest<br />

that ApoE-/- mice in DLAN have increased atherosclerotic lesion area compared to ApoE-/- mice in<br />

12L:12D. These data suggest that DLAN disrupts eating behavior rhythms and may also increase<br />

atherosclerosis.<br />

68


53<br />

TRAF3 negatively regulates platelet activation and thrombosis<br />

Rui Zhang, PhD 1 • Guoying Zhang, MD 1 • Binggang Xiang, MD, PhD 1 • Xiaofeng Cheng, MD, PhD 2 •<br />

Lijang Tang, MD 3 • Shaojun Shi, MD 4 • Yani Liu, MD 4 • Xun Ai, PhD 5 • Ping Xie, PhD 6 •<br />

Zhenyu Li, MD, PhD 1<br />

1Division of <strong>Cardiovascular</strong> Medicine, University of Kentucky • 2 Taizhou Hospital, Wenzhou Medical<br />

University • 3 Department of Cardiology, Zhejiang Hospital • 4 Department of Pharmacy, Huazhong<br />

University of Science and Technology • 5 Department of Physiology and Biophysics, Rush University<br />

• 6 6Department of Cell Biology and Neuroscience, Rutgers University<br />

Faculty<br />

CD40 ligand (CD40L), a member of the tumor necrosis factor (TNF) superfamily, binds to CD40,<br />

leading to many effects depending on target cell type. Platelets express CD40L and are a major<br />

source of soluble CD40L. CD40L has been shown to potentiate platelet activation and thrombus<br />

formation, involving both CD40-dependent and -independent mechanisms. A family of proteins<br />

called TNF receptor associated factors (TRAFs) plays key roles in mediating CD40L-CD40 signaling.<br />

Platelets express several TRAFs. It has been shown that TRAF2 plays a role in CD40L-mediated<br />

platelet activation. Here we show that platelets also express TRAF3, which plays a negative role in<br />

regulating platelet activation. Thrombin- or collagen-induced platelet aggregation and secretion are<br />

increased in TRAF3 knockout mice. The expression levels of collagen receptor GPVI and integrin<br />

αIIbβ3 in platelets were not affected by deletion of TRAF3, suggesting that increased platelet<br />

activation in the TRAF3 knockout mice was not due to increased expression platelet receptors.<br />

Time to formation of thrombi in a FeCl3-induced thrombosis model was significantly shortened in<br />

the TRAF3 knockout mice. However, mouse tail-bleeding times were not affected by deletion of<br />

TRAF3. Thus, TRAF3 plays a negative role in platelet activation and in thrombus formation in vivo.<br />

69


54<br />

Impact of miR-33 antagonism on metabolic parameters in nonhuman primates<br />

Tara E. Keenan 1 • Tong Li, MD 1 • Lei Cai, PhD 1 • Sierra M. Paxton 1 • Courtney R. Burkett 1 • Peter<br />

I. Hecker 1 • Ryan E. Temel, PhD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center and Department of Pharmacology and Nutritional Sciences,<br />

University of Kentucky<br />

Undergraduate<br />

Introduction: MicroRNA-33a (miR-33a) and miR-33b regulate lipid homeostasis by inducing<br />

degradation or blocking translation of mRNAs encoding proteins that control cholesterol efflux and<br />

fatty acid oxidation. By stimulating macrophage cholesterol efflux and promoting antiinflammatory<br />

macrophage polarization, antagonism of miR-33a in mice reduces atherosclerotic.<br />

However, some mouse studies have shown that disruption of miR-33 function has negative<br />

metabolic effects such as increased plasma and hepatic triglycerides. Mouse studies have limited<br />

translational value since mice express only one of the two miR-33 family members found in<br />

humans. Since nonhuman primates (NHPs) have miR-33a and miR-33b, NHPs are the best<br />

preclinical model for determining the therapeutic potential of miR-33 antagonism. The objective of<br />

this project was to determine whether miR-33 antagonism has adverse metabolic effects on NHPs.<br />

Methods: Liver was collected via laparotomy from 12 chow fed male cynomolgus monkeys. Male<br />

cynomolgus monkeys (n=36) were fed for 20 months a high fat/high cholesterol diet, which caused<br />

hypercholesterolemia and atherosclerosis development. At the end of the 20-month progression<br />

phase, a subset of monkeys (n=12) were euthanized to collect tissues. The remaining monkeys were<br />

switched to a cholesterol-lowering “chow” diet and treated with either vehicle (n=12) or anti-miR-<br />

33 (n=12) for 6 months. Blood was collected at 20 months of progression and 2, 4, and 6 months of<br />

regression and the serum was sent to ANTECH Diagnostics for chemical analysis. Liver lipid content<br />

was biochemically determined.<br />

Results: Feeding the monkeys a chow diet for 6 months caused serum triglycerides (TG) to<br />

significantly increase and total cholesterol (TC) to significantly decrease. However, serum TG and<br />

TC were similar for the vehicle and anti-miR-33 treated monkeys. The progression group had<br />

significantly greater hepatic TC and TG compared to the regression groups. Hepatic TC and TG<br />

levels of the vehicle and anti-miR-33 groups were similar and had returned to the baseline levels<br />

observed in monkeys fed only chow. In line with the liver lipids changes, serum ALT and AST levels<br />

were reduced to a similar extent in the regression NHPs. In addition, body weights and serum<br />

glucose concentrations were similar for the vehicle and anti-miR-33 treated NHPs during the 6-<br />

month regression phase.<br />

Conclusion: Metabolic parameters are normal in chow-fed NHPs treated with miR-33 antagonist.<br />

70


55<br />

ATF6 proteins regulate cardiac hypertrophy during pressure overload in the mouse heart<br />

Robert Correll, PhD 1 • Jeffrey Lynch, PhD 1 • Michelle Sargent 1 • Allen York 1 • Jeffery Molkentin, PhD 1<br />

1Molecular <strong>Cardiovascular</strong> Biology, Cincinnati Children's Hospital<br />

Postdoc<br />

Objective: The activating transcription factor 6 (ATF6) branch of the endoplasmic reticulum (ER)<br />

unfolded protein response (UPR) plays a critical protective role in the heart’s response to acute<br />

injury or long-term hemodynamic stress that results in cardiac hypertrophy. Here we seek to<br />

elucidate the molecular mechanisms by which engagement of ATF6 proteins results in protective<br />

signaling in the context of pressure overload in the mouse heart.<br />

Methods and Results: Overexpression of thrombospondin-4 (Thbs4) results in a protective ER<br />

stress response and mice gene-deleted for Thbs4 demonstrated compromised ER stress signaling,<br />

inhibition of ATF6α processing and nuclear localization, and decreased survival after transverse<br />

aortic constriction (TAC) or myocardial infarction (MI) surgery. Using gene-deleted mice lacking<br />

ATF6α we demonstrate that Thbs4-mediated upregulation of ER protein chaperone expression and<br />

expansion of the ER compartment requires ATF6α expression. Furthermore, mice lacking ATF6α or<br />

the related protein ATF6β show defects in the hypertrophic response after pressure overload,<br />

leading to accelerated decompensation and failure after long-term TAC surgery, accompanied by<br />

reduced expression of ER protein chaperones.<br />

Conclusion: We find that both ATF6α and ATF6β proteins are required for compensatory<br />

hypertrophy and ER chaperone mobilization following pressure overload in the mouse heart. We<br />

hypothesize that the inability to upregulate chaperone expression during pressure overload results<br />

in diminished ER protein folding capacity that impairs the hypertrophic response. These results<br />

position ATF6 proteins as essential regulators of compensatory cardiac hypertrophy following<br />

chronic hemodynamic stress.<br />

71


56<br />

Isolation and characterization of primary bone marrow mesenchymal stem cells.<br />

Eman El-sawalhy, MD 1 • Lakshman Chelvarajan, PhD 2 • Ahmed Abdel-Latif, MD, PhD 1<br />

1Division of <strong>Cardiovascular</strong> Medicine, Gill Heart Institute, University of Kentucky • 2 Saha<br />

cardiovascular research center, University of Kentucky<br />

Postdoc<br />

•Introduction: Myocardial infarction remains a major clinical problem and the leading cause of<br />

mortality in the world. Bone marrow derived stem cells have the capacity to participate in cardiac<br />

repair and regeneration of compromised heart muscle. The aim of this study is to generate highly<br />

enriched mesenchymal stem cells to inject 3x106 into the hearts of mice recovering from a<br />

myocardial infarction.<br />

•Methods: We isolated bone marrow (BM) from crushed long bones and hip bones of 6-8 weeks old<br />

GFP positive mice (C57BL/6). The stem cells were cultured in MesenCult media supplemented with<br />

MesenPure. Cells were cultured under either normoxic or hypoxic conditions (4% O2) for about<br />

two weeks. The cultures were then passaged when they reached 80% confluence. The cells were<br />

analyzed by flow cytometry using mesenchymal stem cell (CD90.2 and SCA-1) and hematopoietic<br />

(CD45) markers.<br />

•Results: As expected, the baseline bone marrow cells were negative for both stem cell markers,<br />

CD90 and Sca-1, while expressing the hematopoietic marker, CD45 (80%). During early expansion<br />

all the CD45– cells were Sca1+CD90–. Following subsequent passaging of the enriched cells, they<br />

began to express CD90. By the end of the second passage, the proportion of Sca1+CD90+<br />

mesenchymal stem cells was 65%, while cells expressing Sca-1 alone was down to 32%. Most of the<br />

live healthy cells remained GFP+ throughout the expansion and passaging.<br />

Conclusion: Mesenchymal stem cells can be isolated and enriched from murine bone marrow in<br />

sufficient amounts to be used in our in vivo study to enhance regeneration of cardiomyocytes and<br />

restore cardiac function after myocardial infarction.<br />

72


57<br />

Fine Tuning Platelet Secretion to Modulate Hemostasis<br />

Smita Joshi, MS 1 • Irina Pokrovskaya, MS 2 • Brian Storrie, PhD 2 • Sidney W. Whiteheart, PhD 1<br />

1Molecular and Cellular Biochemistry, University of Kentucky • 2 Department of Physiology and<br />

Biophysics, University of Arkansas for Medical Sciences<br />

Graduate Student<br />

Globally, occlusive thrombotic events: e.g., heart attacks and cerebral strokes, cause > 50% of total<br />

deaths attributed to the noninfectious disease. However, aggressive attempts to limit thrombosis<br />

cause bleeding, which can be equally catastrophic. What is needed is a strategy to limit clot<br />

formation, but not prevent it. Platelets play a critical role in controlling bleeding by sensing vascular<br />

damage and releasing a host of components to seal breaches. This secretion process is mediated by<br />

Soluble N-ethylmaleimide Sensitive Factor Attachment Protein Receptors (SNAREs) and their<br />

regulators. To drive secretion, vesicle (v)-SNARE on granules and target (t)-SNARE on the plasma<br />

membrane (PM) form a trans-bilayer complex that mediates membrane fusion. Syntaxin 11 and<br />

SNAP-23 form the functionally relevant t-SNARE heterodimer. For v-SNAREs, platelets contain<br />

Vesicle-Associated Membrane Protein (VAMP)-2, -3, -4, -5, -7, and -8. We focused on how the<br />

platelet VAMPs influence secretion and whether modulating secretion can modulate clot formation.<br />

To address this goal, we genetically titrated the different VAMPs to define their roles in exocytosis<br />

and hemostasis.<br />

We gathered global VAMP-3-/- and VAMP-8-/- animals. To overcome embryonic lethality of global<br />

VAMP-2 deletion, we generated platelet-specific VAMP-2/3-/- mice by using a tissue-specific<br />

promoter that facilitates expression of tetanus toxin that cleaves VAMP-2 and 3. We crossed these<br />

with VAMP-8-/- mice to create platelet-specific VAMP-2/3/8-/- mice. Structural analysis of wildtype<br />

and VAMP-deficient platelets showed that the α granule cargo solubilization/decondensation<br />

follows granule fusion. To define the structure of secretion, activation intermediates were fixed at<br />

various time points, post stimulation, and electron microscopy was performed. The data indicate<br />

that granule decondensation is time- and agonist concentration-dependent. Moreover,<br />

decondensation of granule cargo was VAMP dependent. Three dimensional EM analyses indicate<br />

that VAMP-8 plays a major role in compound, intra-granule fusion and also contributes to single,<br />

granule-PM fusion. Our structural data elucidate how platelet secretion occurs at the cellular level<br />

and explains the complex secretion kinetics previously reported in activated platelets.<br />

To further measure the functional importance of the VAMPs, ex vivo secretion assays were used to<br />

monitor the kinetics and the extent of release from all three platelet granules (dense, α, and<br />

lysosomes). Only VAMP-2/3/8-/- platelets showed a robust defect in secretion (~70% decrease),<br />

more than observed for VAMP-8-/- platelets (~50%). When we studied the effects of secretion on<br />

hemostasis, only VAMP-2/3/8-/- mice showed significantly increased tail-bleeding times and<br />

delayed arterial thrombosis. VAMP-8-/- animals did show a delay in thrombus formation but no<br />

overt bleeding diathesis. Our data show that small differences in secretion kinetics alter hemostasis,<br />

thus by modulating platelet secretion, we can control thrombus formation without inducing<br />

pathological bleeding. These data identify the secretory machinery as a viable target to control<br />

occlusive cardiovascular diseases.<br />

Our work is the first comprehensive study showing how by targeting secretion we can achieve the<br />

long-sought balance between occlusive thrombosis and spurious hemostasis. Additionally, by<br />

titrating amounts and types of VAMPs in platelets we have created a valuable set of animals to<br />

precisely analyze the role of platelet secretion in other vascular processes.<br />

73


58<br />

The XY sex chromosome complement augments Ang-II induced aortic arch aneurysms in<br />

female LDLr-/- mice<br />

Cassandra Woolley 1 • Yasir Al-Siraj 1 • Sean Thatcher, PhD 1 • Lisa Cassis, PhD 1<br />

1Department of Pharmacology and Nutritional Sciences, University of Kentucky<br />

Undergraduate<br />

Objective: Sex difference in cardiovascular disease has been a subject of research efforts aiming to<br />

improve the efficacy and approach of therapeutics available. In humans, abdominal aortic<br />

aneurysms (AAAs) display sexual dimorphism, with higher risk for development in males but with<br />

females exhibiting more rapid AAA growth rates and AAA ruptures at smaller aneurysm sizes.<br />

Previous studies performed in our laboratory have demonstrated that testosterone increases<br />

incidence and rupture rate of angiotensin II (AngII)-induced AAA in hyperlipidemic mice. After<br />

establishing this relationship, the four-core mouse model was used to analyze the role of sex<br />

chromosomes separate from sex hormones in aneurysm pathology. Female XY LDLr-/- mice are<br />

more susceptible to AngII-induced AAA than female XX LDLr-/- mice. The XY chromosome<br />

complement demonstrated more severe pathology and higher rupture rate. However, studies<br />

examining the role of sex chromosomes in the aortic arch between XX and XY female mice have not<br />

been performed. The purpose of this preliminary study was to observe whether differences were<br />

present between female XX and XY mice in formation of the aortic arch aneurysm.<br />

Methods and Results: Female XX and XY LDLr-/- mice were placed on a Western diet (TD.88137)<br />

one week prior to implantation of a 28-day AngII osmotic pump. The pumps administered AngII<br />

(1,000 ng/kg/min) for 28 days to induce aneurysm formation. The body weight of the mice was<br />

recorded weekly. Baseline measurements of the aortic arch diameter were made at D0 using<br />

ultrasound and found to be significantly different between XX and XY females (XX, 1.4 ± 0.03; XY,<br />

1.5 ± 0.05 mm; p


59<br />

Multilevel Mechanical Testing of Cardiac Valves<br />

Arielle Waller 1 • Daniel Perry 1 • Luke Knudson 1 • RS Baker 2 • David Morales, MD 3 •<br />

Farhan Zafar, MD 2 • Daria Narmoneva, PhD 1<br />

1Biomedical Engineering, University of Cincinnati • 2 Division of Pediatric Cardiothoracic Surgery,<br />

The Heart Institute, Cincinnati Children's Hospital • 3 Division of Pediatric Cardiothoracic Surgery,<br />

The Heart Institute, Cincinnati Children's Hospital<br />

Graduate Student<br />

The lack of adequate heart valve replacement options represents a major problem in pediatric care,<br />

where multiple operations are required to accommodate patient growth. Bioengineered valves may<br />

provide a viable alternative to existing strategies. Knowledge of the relationship between macroand<br />

micro-biomechanical properties and functional behavior of native or engineered valve tissue is<br />

critical for success of bioengineered valves, yet it is still poorly understood. Here, a tubular<br />

tricuspid valve bioprosthesis made of small intestinal submucosa-derived extracellular matrix (SIS-<br />

ECM) was used as a valve replacement in the in vivo sheep model. Current study developed distinct<br />

multilevel testing approaches to determine valve tissue biomechanical properties and quantify the<br />

structure-function and behaviors. The following analyses were performed: (i) tissue/organ level<br />

uniaxial testing of valve samples; (ii) microanalyses (cellular/subcellular level) of adjacent fullthickness<br />

valve sections using atomic force microscopy (AFM) to determine valve mechanical<br />

properties. The AFM approach was used in combination with MATLAB-based quantitative 2D<br />

histological mapping of valve matrix content (collagen & proteoglycans), for functional analyses of<br />

biomechanical behavior. Results demonstrated that valve tensile elastic modulus was higher for the<br />

valve annulus vs. the cusp, consistent with proteoglycan rich regions on the distal end of the cusp,<br />

and a collagen rich region on the proximal end of the cusp and fibrosa. Compression stiffness from<br />

AFM testing demonstrated an increased Young’s modulus for the fibrosa vs. spongiosa, with<br />

intermediate values for atrialis (mitral and tricuspid) and ventricularis (aortic and pulmonary),<br />

consistent with a collagen-rich fibrosa, proteoglycan-rich spongiosa, and elastin-rich<br />

atrialis/ventricularis. In summary, this demonstrates feasibility of this multilevel testing approach<br />

in functional assessment of bioengineered valve and its ability to provide necessary mechanical<br />

function immediately upon implantation, and to attain structural and biomechanical properties of<br />

the native tissue during growth and remodeling.<br />

75


60<br />

CHROME: a Long Non-coding RNA that Regulates Cholesterol Homeostasis<br />

Kathryn Moore, PhD 1<br />

1Medicine, New York University<br />

Faculty<br />

Thousands of long non-coding RNAs (lncRNAs) have been identified in the human genome, many of<br />

which are not conserved in lower mammals. The majority of these lncRNAs remain functionally<br />

uncharacterized and may have important implications in human physiology and disease. We<br />

identified a primate-specific lncRNA, CHROME, which is increased in the plasma and atherosclerotic<br />

plaques of individuals with coronary artery disease compared to healthy controls. Using gain- and<br />

loss-of-function approaches, we show that CHROME functions as a competing endogenous RNA of<br />

microRNAs (miRNAs) that repress cellular cholesterol efflux and plasma high density lipoproteins<br />

(HDL) levels, and regulates the concentration and biological functions of these miRNAs. CHROME<br />

knockdown in primary hepatocytes increases levels of its miRNA binding partners, thereby<br />

reducing expression of their target gene networks, hepatic cholesterol and phospholipid efflux, and<br />

the formation of nascent HDL particles. Consistent with these findings, hepatic levels of CHROME<br />

are positively correlated with plasma levels of HDL cholesterol in healthy individuals. Collectively,<br />

our findings identify CHROME as a central component of the non-coding RNA circuitry controlling<br />

cholesterol homeostasis in humans.<br />

76


61<br />

Secretory phospholipase A2 group IIA (PLA2G2A) enhances metabolism and insulin<br />

sensitivity<br />

Michael Kuefner 1 • Kevin Pham 1 • JeAnna Redd 2 • Erin Stephenson, PhD 3 • Innocence Harvey 2 •<br />

Xiong Deng, PhD 1 • Dave Bridges, PhD 2 • Eric Boilard, PhD 4 • Marshal Elam, MD, PhD 1 •<br />

Edwards Park, PhD 1<br />

1Pharmacology, University of Tennessee Health Science Center • 2 Nutritional Sciences, University of<br />

Michigan School of Public Health • 3 Physiology, University of Tennessee Health Science Center •<br />

4Infectious Diseases and Immunity, CHUQ <strong>Research</strong> Center and Division of Rheumatology<br />

Graduate Student<br />

Secretory phospholipase A2 group IIA (PLA2G2A) is a member of a family of secretory<br />

phospholipases that have been implicated in inflammation, atherogenesis, and antibacterial actions.<br />

Here, we evaluated the role of PLA2G2A in the metabolic response to a high fat diet. C57BL/6<br />

(BL/6) mice do not express PLA2g2a due to a frameshift mutation. We fed BL/6 mice expressing<br />

the human PLA2G2A gene (IIA+ mice) a fat diet and assessed the physiologic response. After 10<br />

weeks on the high fat diet, the BL/6 mice were obese, but the IIA+ mice did not gain weight or<br />

accumulate lipid. The lean mass in chow- and high fat-fed IIA+ mice was constant and similar to the<br />

BL/6 mice on a chow diet. Surprisingly, the IIA+ mice had an elevated metabolic rate, which was not<br />

due to differences in physical activity. The IIA+ mice were more insulin sensitive and glucose<br />

tolerant than the BL/6 mice, even when the IIA+ mice were provided the high fat diet. The IIA+<br />

mice had increased expression of uncoupling protein 1 (UCP1), sirtuin 1 (SIRT1), and PPARγ<br />

coactivator 1α (PGC-1α) in brown adipose tissue (BAT), suggesting that PLA2G2A activates<br />

mitochondrial uncoupling in BAT. Our data indicate that PLA2G2A has a previously undiscovered<br />

impact on insulin sensitivity and metabolism.<br />

77


62<br />

Making Good: Secretory Quality Control in Lipoprotein Lipase Trafficking<br />

Benjamin Roberts 1 • Saskia Neher, PhD 1<br />

1Biochemistry and Biophysics, UNC Chapel Hill<br />

Graduate Studnet<br />

Lipoprotein lipase (LPL) is an essential vascular regulator of serum triglycerides. Patients without<br />

LPL activity suffer from hypertriglyceridemia. Chronic elevated blood triglycerides increase the<br />

risks of acute pancreatitis, atherosclerosis, and cardiac disease. There is no cure for LPL deficiency<br />

available in the United States. Of the over 70 clinical LPL clinical mutations, some affect intracellular<br />

LPL trafficking. It is clear that misfolded LPL is subject to post-Endoplasmic Reticulum (ER) quality<br />

control, which results in its degradation. The regulation of this process and the LPL partners that<br />

promote LPL degradation are not well understood. To study atypical LPL trafficking we<br />

fluorescently tagged two clinically-identified LPL variants to follow intracellular LPL transport. We<br />

also characterized the trafficking of WT LPL produced in cells lacking its folding chaperone Lipase<br />

Maturation Factor 1. Finally, we used mass spectrometry to search for intracellular binding<br />

partners unique to misfolded LPL. Using these techniques, we quantified post-ER quality control of<br />

folded and misfolded LPL. These studies enhance our understanding of the regulation in LPL<br />

trafficking and help to explain the consequences of some LPL mutations resulting in LPL deficiency.<br />

78


63<br />

Gut Microbial Trimethylamine (TMA) Lyase Activity Coordinates Circadian Rhythms in Host<br />

Hepatic Lipid and Bile Acid Metabolism<br />

Christy Gliniak, PhD 1 • Rebecca Schugar, PhD 1 • Robert Helsley, PhD 1 • Anthony Gromovsky 1 •<br />

Chase Neumann 1 • Zeneng Wang, PhD 1 • Stanley Hazen, MD, PhD 2 • J. Mark Brown, PhD 2<br />

1Department of Cellular and Molecular Medicine, Cleveland Clinic • 2 Department of Cellular and<br />

Molecular Medicine, Center for Microbiome & Human Health, Cleveland Clinic<br />

Faculty<br />

From cyanobacteria to humans, circadian rhythms evolved to allow an organism to adapt and<br />

anticipate environmental cues, particularly events that regulate energy metabolism. Misalignment<br />

of circadian rhythms are associated with increased incidence of obesity, diabetes, cardiovascular<br />

disease, cancer, and other inflammatory disorders. Intestinal microbial composition and structure<br />

displays circadian rhythmicity, and the gut microbiome itself can regulate host endogenous<br />

circadian rhythms. However, it is not well understood how gut microbes regulate host metabolism<br />

and circadian rhythms. Gut microbes contribute to the production of the circulating metabolite<br />

trimethlyamine-N-oxide (TMAO), which is associated with cardiovascular disease in humans, and<br />

has been shown to enhance atherosclerosis and thrombosis potential in mice. Microbes produce<br />

trimethlyamine (TMA) from dietary choline or carnitine, which is later converted by the host to<br />

TMAO, primarily by host liver flavin monooxygenase 3 (FMO3). Previous studies have shown that<br />

pharmacologic inhibition of microbial TMA lyase activity or inhibition of FMO3 results in decreased<br />

atherosclerosis in mice, and the expression of the TMAO producing enzyme FMO3 exhibits<br />

circadian rhythmic patterns in the liver. Here we hypothesized that the co-metabolites TMA and<br />

TMAO may serve as gut microbe-derived signals that entrain host metabolic circadian rhythms,<br />

thereby impacting cardiometabolic disease. To test this we treated C57BL/6 mice with a highly<br />

potent and selective second-generation TMA lyase inhibitor CC08, and examined effects on<br />

circadian rhythms in host metabolism. As expected, mice treated with CC08 displayed reduced<br />

plasma TMA/TMAO levels across an entire 24-hour period. Unexpectedly, TMA lyase inhibition<br />

resulted in increased expression of the key nuclear receptors that regulate the circadian clock<br />

including Bmal1 (Arntl1) and Rev-erbα (Nr1d1) during the light cycle in the liver. The well known<br />

circadian cycling of transcription factors orchestrating hepatic fatty acid metabolism such as<br />

Srebp1c and Pparα were markedly altered in CC08-treated mice. TMA lyase inhibition resulted in<br />

elevated hepatic expression of Srebp1c during the light cycle, yet suppressed hepatic Pparα<br />

expression during the dark cycle. Furthermore, the expression of the bile acid-sensing nuclear<br />

receptor Fxr was lower in TMA lyase-inhibited animals during the dark cycle, which is associated<br />

with alterations in hepatic Fxr target gene expression and circulating bile acid levels. Collectively,<br />

these data suggest that pharmacologic inhibition of gut microbial TMA lyase activity can alter host<br />

transcriptional programs that dictate hepatic circadian rhythms in lipid and bile acid metabolism.<br />

These data provide the first clues into mechanisms by which TMA lyase inhibitors may protect mice<br />

against cardiometabolic disease.<br />

79


64<br />

Thrombospondin 1 (TSP1) Deficiency Protects Against Diet-Induced Fatty Liver Disease<br />

Courtney Turpin, MS 1 • Heather Norman-Burgdolf, PhD 2 • Ling Yao, MS 1 • Yanzhang Li, PhD 3 •<br />

Shuxia Wang, MD, PhD 1<br />

1Department of Pharmacology and Nutritional Sciences, University of Kentucky • 2 Department of<br />

Dietetics and Human Nutrition, University of Kentucky • 3 Department of Internal Medicine,<br />

University of Kentucky<br />

Graduate Student<br />

Background: Non-alcoholic fatty liver disease (NAFLD) is a widespread disease, affecting around<br />

20-30% of American adults with prevalence on the rise in many age groups. Obesity is thought to<br />

play a contributing role in the occurrence of this disease. NAFLD progression includes an initial<br />

state lipid accumulation, which is worsened by additional stresses. Thrombospondin 1 (TSP1) is a<br />

secreted matricellular protein that has been implicated in playing a role in causing obesityassociated<br />

inflammation, lipid accumulation, and fibrosis in various tissues, but TSP1 expression in<br />

the liver and its possible role in pathogenesis are not known.<br />

Methods: Eight-week-old control and TSP1 deficient mice were fed at either a low-fat (10% kcal<br />

from fat) or high-fat (60%kcal from fat) for 16 weeks. Liver histology, gene expression, and<br />

immunohistochemistry were performed to observe the effect of TSP1 deficiency on the liver<br />

physiology.<br />

Results: TSP1 expression was found to be significantly increased in control high-fat diet fed mice<br />

liver tissue. Liver histology showed less lipid accumulation in the TSP1 deficient mice fed a high-fat<br />

diet, which was further confirmed by reduced triglyceride levels. Although there was no significant<br />

change fatty acid uptake in the whole liver, there was a significant decrease in CD36 expression in<br />

the hepatocytes of the deficient mice, which also had reduced fatty acid uptake. There was also a<br />

significant decrease in de novo lipogenesis genes PPARγ and SREBP1c, but with normal feeding,<br />

there was no significant change in triglyceride production or secretion. In addition to the changes in<br />

lipid content, there was a reduction in inflammatory markers and the fibrosis marker Collagen1α1,<br />

but there were no observed changes in fibrosis histology staining.<br />

Discussion and implications: The findings of this study suggest that TSP1 expression could play a<br />

role in the development of the hallmark signs of NAFLD. Further studies using a NAFLD animal<br />

model and cell culture could help elucidate the mechanism of its involvement. In summary, the data<br />

suggests that TSP1 has involvement in lipid accumulation and the resulting inflammation and<br />

fibrosis that are seen in progressed disease states of NAFLD.<br />

80


65<br />

An obesity-generating diet drives the cancer stem cell phenotype and glioblastoma<br />

progression.<br />

Daniel J Silver, PhD 1 • Gustavo A Roversi 1 • Anthony Gromovsky 1 • J Mark Brown, PhD 1 • Justin<br />

D Lathia, PhD 1<br />

1Cellular and Molecular Medicine, Cleveland Clinic<br />

Staff<br />

Glioblastoma (GBM) is the most prevalent and lethal brain cancer. The disease occurs in two to<br />

three per 100,000 adults annually and accounts for approximately half of all brain cancers. While<br />

there are no known causes for GBM, obesity is an established risk factor for cancer in general.<br />

Recent work confirmed that overweight and obese women are at greater risk of developing glioma<br />

compared to women of healthy body weight. This finding represents a major change in the<br />

consideration of body mass for brain cancer patients, a factor that has been largely ignored in the<br />

clinic. Furthermore, it is well-established that consumption of a Western-pattern diet leads to<br />

increased rates of obesity. For these reasons, we hypothesized that obesity accelerates GBM<br />

progression by driving tumor cell proliferation and/or cancer stem cell enrichment. We have tested<br />

this hypothesis in vivo using three syngeneic glioma models transplanted into the brains of<br />

immune-competent C57BL/6 mice. Mice were maintained on either an obesity-generating, high-fat<br />

diet (HFD) or a standard rodent chow diet. Tumor-bearing mice fed the HFD succumbed to disease<br />

nearly two-fold faster than those fed the chow diet. For example, mice transplanted with the GL261<br />

syngeneic glioma model and maintained on HFD were culled, on average, 16 days earlier than those<br />

maintained on chow. Furthermore, we noted a nearly three-fold increase in the frequency of tumor<br />

generation in obese animals compared to lean, suggesting that systemic obesity enriches for a<br />

tumor-initiating cancer stem cell population in the brain. Tumor cells treated directly with oleic<br />

acid or linoleic acid in vitro demonstrated increased viability and enhanced sphere formation<br />

compared to vehicle controls. These data indicated that certain lipid components of the obesitygenerating<br />

diet were sufficient to drive tumor cell proliferation and the emergence of the cancer<br />

stem cell state. In order to identify the set of lipid species contributing to accelerated disease<br />

progression, we profiled the major lipids present in tumors of obese mice compared to tumors of<br />

lean mice using untargeted lipidomics. This analysis revealed four putative oncogenic lipids. These<br />

species were robustly expressed in tumors resected from obese mice compared to tumors resected<br />

from lean mice. We have additionally identified two potentially tumor-suppressive lipids that were<br />

expressed strongly in the contralateral hemisphere of lean mice compared to tumors resected from<br />

either lean or obese mice. This work confirms a shift in the lipid profile of tumors developing in the<br />

brains of the obese mice and suggests that select lipid species may directly drive the increased<br />

tumor cell proliferation and enhancement in the cancer stem cell compartment that we observe in<br />

vivo.<br />

81


66<br />

Serum Amyloid A3 is a High Density Lipoprotein-associated Acute Phase Protein<br />

Maria De Beer, PhD 1 • Ailing Ji, PhD 2 • Victoria Noffsinger 2 • Preetha Shridas, PhD 2 • Frederick De<br />

Beer, MD 2 • Lisa Tannock, MD 2 • Nancy Webb, PhD 2<br />

1Physiology, University of Kentucky • 2 Internal Medicine, University of Kentucky<br />

Faculty<br />

Acute phase serum amyloid (SAA) is a family of evolutionarily conserved, secreted proteins that<br />

exerts innate functions relevant to obesity and diabetes. In humans, two SAA isoforms (SAA1 and<br />

SAA2) are highly induced in the liver and extrahepatic tissues under the regulation of inflammatory<br />

cytokines. During severe inflammation, SAA1/2 levels can increase >1000-fold in plasma, where it<br />

is found associated with HDL. Mice produce an additional acute phase SAA, SAA3, which is thought<br />

to be produced mainly by adipocytes and macrophages and has not previously been found<br />

circulating on HDL.<br />

Objectives: The goal of this study was to investigate whether SAA3 serves as a third liver-derived,<br />

HDL-associated acute phase SAA in mice.<br />

Methods: Using isoform-specific oligonucleotide primers for qRT-PCR, we determined that SAA3 is<br />

transcriptionally induced to a similar extent (~2500-fold) compared to SAA1.1/2.1 (~6000-fold) in<br />

livers of C57BL/6 mice 19 hr after lipopolysaccharide (LPS) injection (100 µg/mouse). SAAs were<br />

also robustly induced in fat tissue (SAA1/2~100-fold; SAA3~400-fold). The analysis of primary<br />

mouse hepatocytes and in situ hybridization of mouse liver sections indicated that liver-derived<br />

SAAs are produced by hepatocytes and not other stromal cells, including Kupffer cells. All 3 SAA<br />

isoforms were detected in plasma of LPS-injected mice, although SAA3 levels were ~20% of<br />

SAA1/2. After separation by FPLC, virtually all of plasma SAA1/2 eluted with the HDL fraction,<br />

whereas ~15% of plasma SAA3 appeared to be lipid poor/free. HDL isolated from acute phase<br />

mouse plasma by density gradient ultracentrifugation was subjected to isoelectric focusing to<br />

determine the relative recovery of the various SAA isoforms. Whereas the bulk of plasma SAA1.1<br />

was found in the d=1.063-1.21 fraction, only ~50% of SAA2.1 and ~10% of SAA3 was recovered<br />

after ultracentrifugation. These findings suggest that SAA3 may be more loosely associated with<br />

HDL compared to SAA1.1/2.1, which may give rise to lipid poor/free SAA3 that is susceptible to<br />

more rapid clearance in vivo.<br />

Conclusions: We conclude that SAA3 is a major hepatic acute phase SAA in mice that may produce<br />

systemic effects during inflammation. Future studies investigating SAA pathobiology in mice must<br />

take into account the previously under-studied SAA3.<br />

82


67<br />

An XX Sex Chromosome Complement Promotes Hypercholesterolemia and Atherosclerosis<br />

in Ldlr-/- Mice Fed Western Diet<br />

Yasir Alsiraj, MS 1 • Sean Thatcher, PhD 1 • Lei Cai, PhD 2 • Ryan Temel, PhD 2 • Patrick Tso, PhD 3 •<br />

Lisa Cassis, PhD 1<br />

1Pharmacology and Nutritional Sciences, University of Kentucky • 2 Saha <strong>Cardiovascular</strong> <strong>Research</strong><br />

Center, University of Kentucky • 3 Department of Pathology and Laboratory Medicine, University of<br />

Cincinnati<br />

Graduate Student<br />

Objectives: Sex hormones are primary contributors to sexual dimorphism of cardiovascular<br />

diseases, but little is known about the influence of genes on sex chromosomes as mediators of<br />

cardiovascular sex differences. In this study, we hypothesized that genes on sex chromosomes<br />

influence the development of hypercholesterolemia and atherosclerosis.<br />

Methods and Results: Transgenic male mice with deletion of Sry from the Y-chromosome<br />

expressing Sry on autosomes (8-12 weeks of age) were bred to female Ldlr-/- mice to generate<br />

female and male mice with an XX or an XY sex chromosome complement. Male (M) and female (F)<br />

mice were fed a Western diet (Teklad TD88137) for 3 months. XX mice exhibited increased body<br />

weights compared to XY mice, regardless of gonadal sex (FXX, 38 ± 1.8; FXY, 30.6 ± 1.3 g; P


68<br />

Adipocyte deficiency of ACE2 increases systolic blood pressures of obese female C57BL/6<br />

mice<br />

Robin Shoemaker, PhD 1 • Wen Su, MD 2 • Ming Gong, PhD 2 • Lisa Cassis, PhD 1<br />

1Pharmacology and Nutritional Sciences, University of Kentucky • 2 Physiology, University of<br />

Kentucky<br />

Postdoc<br />

Background: We demonstrated that sexual dimorphism of obesity-hypertension was associated<br />

with differential activity of adipocyte angiotensin-converting enzyme 2 (ACE2) in male versus (vs)<br />

female mice. These data suggest that adipocyte ACE2 regulates blood pressure by influencing the<br />

balance of angiotensin II (AngII, a substrate of ACE2) vs angiotensin-(1-7) (Ang-(1-7)), which<br />

differs in male and female mice. We hypothesized that deficiency of ACE2 in adipocytes increases<br />

blood pressure of HF-fed female mice.<br />

Methods/Results: Mice with adipocyte ACE2 deficiency were developed from breeding Ace2fl/fl<br />

mice to transgenic C57BL/6 mice with heterozygous transgenic expression of Cre recombinase<br />

driven by the adiponectin promoter (Ace2Adipo). Female or male Ace2fl/fl and Ace2Adipo mice (8<br />

weeks old) were fed a HF (60% kcal as fat) or low fat (LF; 10% kcal from fat) diet for 16 weeks,<br />

after which blood pressure was quantified by radiotelemetry. Systolic blood pressures (SBP) were<br />

not different in LF-fed female mice of either genotype (24 hr average SBP [mmHg]: Ace2fl./fl:<br />

121+/-1; Ace2Adipo: 121+/-1; p>0.05). However, SBP was significantly increased in HF-fed female<br />

Ace2Adipo vs Ace2fl/fl mice (Ace2fl/fl: 127+/-2; Ace2Adipo: 133+/-3; p


69<br />

Fish oil-derived long-chain monounsaturated fatty acid (LCMUFA) for cardiovascular<br />

diseases : a novel approach for cardioprotection<br />

Zhihong Yang, PhD 1 • Scott Gordon, PhD 1 • Milton Pryor 1 • Shuibang Wang, PhD 2 •<br />

Robert Danner, MD, PhD 2 • Alan Remaley, MD, PhD 1<br />

1Lipoprotein Metabolism Section, CPB/NHLBI, National Institutes of Health • 2 Critical Care<br />

Medicine Department, Clinical Center, National Institutes of Health<br />

Postdoc<br />

<strong>Cardiovascular</strong> disease (CVD) remains the leading cause of death, disability, and healthcare expense<br />

in the United States and is also a major healthcare problem worldwide. Numerous studies have<br />

shown cardiovascular benefits of fish oil, and most of these favorable effects have been attributed<br />

to omega-3 fatty acids. Fish oils, however, also contain varying amounts of other unusual types of<br />

fatty acids not commonly found in other food sources. For example, oils derived from saury, pollock<br />

and herring are all enriched in long-chain monounsaturated fatty acids (LCMUFA) with aliphatic<br />

tails longer than 18 C atoms (i.e., C20:1 and C22:1 isomers combined). Compared with well-studied<br />

omega-3, limited information is available on the role of LCMUFA in cardiovascular health.<br />

In the current study, we first examined the effect of saury fish oil-derived LCMUFA concentrate on<br />

the pathogenesis of atherosclerosis in atherosclerosis animal model. In LDLR-deficient female<br />

mice, we observed that 12-week supplementation of 2% LCMUFA on a western diet significantly<br />

decreased atherosclerosis lesion areas and accumulation of macrophages, compared with western<br />

diet (control) or western diet supplemented with 2% olive oil enriched in shorter-chain MUFA oleic<br />

acid (C18:1 n-9), although there were no differences in plasma lipoprotein profiles between the<br />

three groups. LCMUFA diet also decreased plasma inflammatory cytokine levels, and improved<br />

cholesterol efflux capacity to apoB-depleted plasma in BHK cells overexpressing ABCA1. RNA<br />

sequencing and subsequent qPCR analyses revealed that LCMUFA upregulated hepatic PPAR<br />

signaling pathway. To clarify the individual effect of LCMUFA isomers, we further produced<br />

concentrated C20:1 and C22:1 fractions, and fed LDLR-deficient mice a western diet supplemented<br />

with 5% C20:1, C22:1, or not (control) for 12 weeks. In good agreement with the first study, both<br />

LCMUFA isomers showed beneficial effects on atherosclerosis development, systematic<br />

inflammation, and cholesterol efflux capacity, without lowering plasma lipids. It is suggested that<br />

the atheroprotective effect of LCMUFA is likely due to both isomer fractions. Alterations in<br />

lipoprotein proteome revealed by LC-MS/MS proteomic analysis were favorably correlated with<br />

reduction in atherosclerotic plaque areas. For mechanistic study, we hypothesized that some of the<br />

beneficial effect of LCMUFA were derived from their metabolite, and we synthesized LCMUFAderived<br />

ethanolamides to estimate their effect on PPAR activation. In vitro PPAR transactivation<br />

assay revealed a beneficial role of LCMUFA-derived ethanolamides in PPAR transcriptional activity.<br />

Based on these positive findings, we are now conducting a double-blind crossover clinical trial of<br />

LCMUFA-rich saury oil to estimate the effect of LCMUFA-rich diet on lipoprotein metabolism in<br />

adults (ClinicalTrials.gov Identifier: NCT03043365).<br />

In conclusion, our research showed for the first time that fish oil-derived LCMUFA-rich diet<br />

attenuates atherosclerosis, possibly by regulating PPAR signaling pathway and modulating<br />

lipoprotein proteome, other than lipid-lowering effects. Although omega-3 fatty acids are generally<br />

considered the major active components in fish lipids, our findings provide novel insights into<br />

potential cardioprotective effect of LCMUFA-rich fish oil, and build on past efforts to understand the<br />

impacts of MUFA on health outcomes.<br />

85


70<br />

Hypercholesterolemia-induced endothelial dysfunction is rescued by overexpression of<br />

endothelial Kir2.1 in resistance arteries<br />

Ibra Fancher, PhD 1 • Sang Joon Ahn, PhD 2 • Crystal Adamos 3 • Catherine Osborn 3 •<br />

Catherine Reardon, PhD 4 • Godfrey Getz, MD, PhD 4 • Shane Phillips, PhD 3 • Irena Levitan, PhD 3<br />

1Medicine, University of Illinois at Chicago • 2 Yale University • 3 University of Illinois at Chicago •<br />

4University of Chicago<br />

Postdoc<br />

Rationale: Hypercholesterolemia induces endothelial dysfunction, a key stage in the development of<br />

cardiovascular disease. Impairment of nitric oxide (NO) dependent vasomotor function is<br />

established as an important factor. We recently identified endothelial Kir2.1 as upstream mediators<br />

of flow-induced NO production. Our earlier studies established that endothelial Kir is suppressed by<br />

cholesterol.<br />

Objective: We tested the hypothesis that hypercholesterolemia induces microvascular endothelial<br />

dysfunction through suppression of Kir2.1, which we propose to be responsible for the inhibition of<br />

flow-induced NO production and the loss of NO-dependent component of flow-induced vasodilation<br />

(FIV).<br />

Methods and Results: Kir2.1 currents and their sensitivity to flow are significantly suppressed in<br />

microvascular endothelial cells exposed to acetylated-LDL without any change in Kir2.1 expression.<br />

Genetic deficiency of Kir2.1 on the background of hypercholesterolemic Apoe-/- mice, Kir2.1+/-<br />

/Apoe-/- exhibit the same blunted FIV and flow-induced NO response as Apoe-/- and Kir2.1+/-<br />

alone, as we showed earlier Kir2.1+/- arteries show significant impairment of (FIV) and NO<br />

production. Endothelial-specific overexpression of Kir2.1 via adenoviral transduction of arteries<br />

from Apoe-/- and Kir2.1+/-/Apoe-/- mice results in full rescue of FIV and NO production in both<br />

hypercholesterolemic models. Conversely, endothelial-specific expression of dominant-negative<br />

Kir2.1 results in impairment of FIV in WT arteries but has no further effect on the blunted FIV in<br />

Apoe-/- arteries. No differences were detected in Kir2.1 or eNOS expression between WT and Apoe-<br />

/- mice. Notably, a full rescue of the FIV response by endothelial-specific Kir2.1 was observed in<br />

Apoe-/- mice with and without the addition of high fat diet.<br />

Conclusions: We conclude that hypercholesterolemia-induced reduction in FIV is largely<br />

attributable to cholesterol suppression of Kir2.1 function via the loss of flow-induced NO<br />

production. The stages downstream of flow-induced Kir2.1 activation appear to be intact because<br />

overexpression of endothelial Kir2.1 rescues FIV and flow-induced NO production in arteries from<br />

hypercholesterolemic mice.<br />

86


71<br />

Fibrinogen Depletion Attenuates Angiotensin II-induced Abdominal Aortic Aneurysm<br />

Hannah Russell 1 • Keith Saum 1 • Alexandra Sundermann 2 • Shannon Jones 1 •<br />

Anders Wanhainen, MD, PhD 3 • Todd Edwards, PhD 2 • Lori Holle 4 • Alisa Wolberg, PhD 4 • A.<br />

Phillip Owens III, PhD 1<br />

1Internal Medicine, University of Cincinnati • 2 Medicine and Public Health, Vanderbilt University<br />

Medical Center • 3 Surgery, Uppsala University • 4 Pathology, UNC Chapel Hill<br />

Graduate Student<br />

Background: Fibrinogen and fibrin [collectively fibrin(ogen)] provides physical and biochemical<br />

support to a developing clot and is one of the most crucial independent risk factors for<br />

cardiovascular diseases (CVDs). In addition to clot formation, fibrin(ogen) also promotes wound<br />

healing and powerful inflammatory and immune responses via engagement of leukocytes.<br />

Increased levels of circulating fibrin(ogen) degradation products are correlated with increased<br />

diameter and progression of the inflammatory disease abdominal aortic aneurysm (AAA). However,<br />

a causal link between fibrinogen and AAA has not yet been established. The objective of this study<br />

was to determine the role of fibrinogen depletion in a mouse model of AAA.<br />

Methods and results: We first determine whether AAA resulted in elevated procoagulant activity by<br />

quantifying plasma levels of thrombin anti-thrombin (TAT) and thrombin generation via calibrated<br />

automated thrombography (CAT). Compared to controls, both mice and humans with AAA had<br />

significantly elevated TAT as well as CAT parameters velocity index, peak height, and endogenous<br />

thrombin potential. To identify a role of fibrinogen in AAA, low density lipoprotein receptor<br />

deficient (Ldlr-/-) mice were injected intraperitoneally with scrambled anti-sense oligonucleotide<br />

(ASO) or β-fibrinogen ASO (30 mg/kg) 3 weeks prior to experimentation and throughout the study.<br />

Administration of fibrinogen ASO successfully achieved > 90% depletion of fibrinogen. After 3<br />

weeks of ASO, mice were fed a high fat/cholesterol ‘Western’ diet for 1 week prior to and<br />

throughout infusion with angiotensin II (AngII; 1,000 ng/kg/day) for 28 days. Compared to<br />

controls, fibrinogen depletion decreased abdominal diameter (33% decrease; P = 0.001),<br />

atherosclerotic lesion area (~63% decrease; P = 0.001), and inflammatory cytokines (>75%<br />

decreased IL-1 and IL-6; P = 0.001). Fibrinogen depletion also decreased aneurysm incidence (P <<br />

0.05) and rupture-induced death (P = 0.078).<br />

Conclusions: Our results show that AAAs are associated with elevated TAT and thrombin<br />

generation in both patients and mice, and that fibrinogen depletion attenuates AAA incidence,<br />

diameter, rupture-induced death, atherosclerosis, and inflammation. We propose that increased<br />

procoagulant activity accelerates the rate of fibrinogen to fibrin conversion, which promotes<br />

inflammation and increases cardiovascular disease. Further studies will define whether reducing<br />

plasma fibrinogen may be a novel treatment strategy.<br />

87


72<br />

Increased Circulating Trimethylamine N-oxide (TMAO) Augments the Incidence of<br />

Abdominal Aortic Aneurysm in Low Penetrant C57BL/6J Mice<br />

Kelsey Conrad, MS 1 • Shannon Jones 1 • Robert Helsley, PhD 2 • Rebecca Schugar, PhD 2 •<br />

Zeneng Wang, PhD 2 • Stanley Hazen, MD, PhD 2 • J. Mark Brown, PhD 2 • A. Phillip Owens III, PhD 1<br />

1Internal Medicine, University of Cincinnati • 2 Cellular and Molecular Medicine, Cleveland Clinic<br />

Graduate Student<br />

Background: The gut microbiota is a metabolically active endocrine organ critical to the<br />

maintenance of cardiovascular health. Nutrients common in high fat foods (phosphatidylcholine,<br />

choline, L-carnitine) are metabolized by microbial enzymes to form the gut microbial metabolite<br />

trimethylamine (TMA). Metabolism by the host enzyme flavin-containing monooxygenase 3 (FMO3)<br />

converts TMA to the pro-inflammatory molecule trimethylamine N-oxide (TMAO). Human clinical<br />

trials have correlated high levels of circulating TMAO to an increased risk of cardiovascular<br />

diseases. However, this meta-organismal pathway has not been evaluated in the context of<br />

abdominal aortic aneurysm (AAA). The objective of this study was to determine the effects of a high<br />

choline diet on the development of AAA.<br />

Methods: C57BL/6J male (n=20) and female (n=20) mice were fed either a standard chow control<br />

diet (n = 10 each sex) or a choline-rich diet (1%; n = 10 each sex) for 5 weeks. After 1 week of diet,<br />

basal abdominal ultrasounds were performed and angiotensin II (AngII; 1,000 ng/kg/min) was<br />

infused for 28 days via implantation of osmotic minipumps. Termination ultrasounds were<br />

performed on day 27 and mice were sacrificed on day 28. Aortas were harvested for evaluation of<br />

aneurysm progression and plasma was analyzed for the metabolites TMA, TMAO, and choline. To<br />

determine whether TMAO was elevated in human patients with AAA, plasma samples from<br />

participants with fast growing AAAs (n = 85), slow growing AAAs (n = 84), and normal (nonaneurysmal)<br />

aortas (n = 115) were analyzed for plasma TMAO levels via liquid chromatography<br />

tandem mass spectrometry (LC-MS/MS).<br />

Results: Administration of a choline-rich diet augmented the incidence (P < 0.02) and aortic<br />

diameter (P < 0.001) of AAAs in both male and female mice versus placebo-fed mice. Plasma levels<br />

of TMA, TMAO, and choline were significantly elevated in choline-fed mice versus normal chow (P <<br />

0.05). Importantly, circulating levels of plasma TMAO were significantly elevated in a step-wise<br />

fashion with the rate of aneurysm growth versus non-aneurysmal control patients (fast growing ><br />

slow growing > normal patients; P < 0.001).<br />

Conclusions: Our results indicate increases in circulating TMAO augments the growth status of<br />

aneurysms in human patients and the incidence of AAA in a low penetrant C57BL/6J mouse model.<br />

88


73<br />

A specific rotamer of apolipoprotein A-I enables Lecithin-cholesterol acyl transferase<br />

activation by discoidal HDL<br />

Allison L. Cooke 1 • Jamie C. Morris 1 • John T. Melchior, PhD 1 • Rong Huang, PhD 1 • W.<br />

Gray Jerome, PhD 2 • Scott E Street 1 • W. Sean Davidson, PhD 1<br />

1Pathology, University of Cincinnati • 2 Pathology, Microbiology, and Immunology, Vanderbilt<br />

University Medical Center<br />

Graduate Student<br />

Investigating the structure of apolipoprotein (apo)A-I, the primary protein component of high<br />

density lipoprotein (HDL), is important for understanding how HDL interacts with lipid-modifying<br />

proteins to mediate its cardioprotective functions in plasma. HDL lipid discs contain two molecules<br />

of apoA-I arranged in an antiparallel, stacked ring-structure. ApoA-I is composed of 10 tandem,<br />

amphipathic, alpha-helical repeats that encapsulate lipid for plasma transport on the hydrophobic<br />

face of the ring-structure, and allows HDL to interact with modifying proteins on the hydrophilic<br />

face. For example, lecithin-cholesterol acyl transferase (LCAT) is a critical lipoprotein-associated<br />

enzyme that converts cholesterol to cholesterol ester for transport out of peripheral cells. It was<br />

hypothesized that changing the orientation of apoA-I on HDL discs can modulate LCAT reactivity.<br />

To test this, site-directed cysteine-point mutagenesis was used to generate different orientations<br />

(rotamers) of apoA-I on HDL discs of similar size and composition: K133C- helix 5 of one apoA-I<br />

molecule adjacent to helix 5 of its antiparallel partner (5/5 rotamer), K206C- helix 5 adjacent to<br />

helix 2 (5/2 rotamer), and K195C-helix 5 adjacent to helix 1 (5/1 rotamer). Initially, an LCAT<br />

activation assay revealed LCAT had significantly increased reactivity to discs with the 5/5 rotamer<br />

relative to wild-type or the other rotamers (p


74<br />

Circulating Bacterial Small RNA Bound to LDL Induce Inflammatory Activation of<br />

Macrophages<br />

Ryan Allen, PhD 1 • Shilin Zhao, PhD 2 • Marisol Ramirez, MS 1 • Bradley Richmond, MD, PhD 3 •<br />

Timothy Blackwell, MD 3 • Quanhu Sheng, PhD 2 • Kasey Vickers, PhD 1<br />

1<strong>Cardiovascular</strong> Medicine, Vanderbilt University Medical Center • 2 Center for Quantitative Sciences,<br />

Vanderbilt University Medical Center • 3 Allergy and Inflammation, Vanderbilt University Medical<br />

Center<br />

Postdoc<br />

Chronic, sub-acute inflammation is an active component of many human diseases of diverse<br />

etiology, characterized by sustained recruitment and activation of macrophages. Macrophages are<br />

phagocytic, myeloid-derived cells that are resident in nearly every tissue to provide innate defense<br />

against invasive pathogens. Upon injury, macrophages respond to remove damaged cells and cell<br />

debris and facilitate tissue repair. However, in disease, prolonged activation of macrophages<br />

promotes tissue remodeling, often to the detriment of tissue function. This is classically observed in<br />

the development of atherosclerosis, in which monocytes infiltrate the artery wall, differentiate to<br />

macrophages, and phagocytize LDL to become cholesterol-engorged “foam cells”, which rapidly<br />

develop a pro-inflammatory phenotype that contributes to further cardiovascular disease. Our lab<br />

previously reported that high-density lipoproteins (HDL) traffic miRNAs between cells as part of<br />

intercellular gene-regulation networks that we proposed could mediate anti-inflammatory<br />

properties of HDL. Although low-density lipoproteins (LDL) have also been reported to traffic<br />

miRNA, more recent data from small-RNA sequencing (sRNA-SEQ) indicates that LDL-associated<br />

sRNA are primarily exogenous, with most sRNA fragments originating from bacteria. Most<br />

interestingly, taxonomic analysis of bacteria contributing sRNA to the LDL pool revealed a profile<br />

distinct from any characterized profile of the comprehensive human microbiome. Additionally,<br />

antibiotic mediated ablation of the gut microbiome failed to disrupt lipoprotein-sRNA pools of mice,<br />

suggesting that bacterial sRNA fragments are not linked to the gut microbiome. However,<br />

manipulation of housing conditions was capable of inducing stark changes in the landscape of<br />

bacterial sRNA bound to lipoproteins of mice, indicative of a potential role for the environment in<br />

shaping the lipoprotein-sRNA fingerprint. In support of this, we characterized the lipoprotein-sRNA<br />

profiles of wild-type and polymeric IgA receptor deficient (Pigr-/-) mice, a model of compromised<br />

airway mucosal immunity, and found reduced abundance of bacterial sRNA fragments, most<br />

notably of Proteobacteria and Firmicutes. Although many potential functions remain to be explored,<br />

we hypothesized that exogenous sRNA associated with LDL may influence the inflammatory<br />

potential of LDL upon uptake by artery-wall macrophages by activation of endosomal, nucleic acidsensing<br />

toll-like receptors (TLR), which are highly expressed in macrophages and facilitate innate<br />

immunity. To test this hypothesis, we treated primary mouse macrophages and PMA-stimulated<br />

THP1 cells with physiologically relevant concentrations of fresh, native LDL (nLDL) and observed<br />

induction of pro-inflammatory cytokine expression. Strikingly, partial silencing of nucleic acidsensing<br />

TLRs blunted this nLDL induced activation of pro-inflammatory gene expression.<br />

Conversely, treatment of human hepatoma cells, which express low levels of exogenous RNAsensing<br />

TLRs, with nLDL failed to induce pro-inflammatory cytokine expression. Taken together,<br />

our data identify a novel, non-lipid cargo of LDL that is capable of modulating inflammatory gene<br />

expression in macrophages and may contribute to the pathogenesis of atherosclerosis, and many<br />

other metabolic diseases.<br />

90


75<br />

Inducible Depletion of Calpain-2 Attenuates Obesity-accelerated Abdominal Aortic<br />

Aneurysms in mice<br />

Aida Javidan, MS 1 • Weihua Jiang, MS 1 • Jessica Moorleghen, MS 1 •<br />

Venkateswaran Subramanian, PhD 2<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Physiology, University of Kentucky<br />

Graduate Student<br />

Background and Objective: Recent clinical studies demonstrated that abdominal adiposity is<br />

associated with increased risk of abdominal aortic aneurysm (AAA) development. Calpains are nonlysosomal<br />

calcium dependent cysteine proteases that are highly expressed in human and<br />

experimental AAAs. Using a pharmacological inhibitor and genetically deficient mice, we identified<br />

that calpain-2 (a major ubiquitous isoform) plays a critical role in Angiotensin II (AngII)-induced<br />

AAA formation in mice. In addition, calpain inhibition strongly suppressed adipose tissue<br />

inflammation in obese mice. The purpose of this study was to determine the functional contribution<br />

of calpain-2 in obesity-accelerated AAA.<br />

Methods and Results: Calpain-2 floxed mice that were hemizygous for β-actin Cre-ERT2 were<br />

produced by breeding male Cre-ERT2 to female calpain-2 floxed mice. At 8 weeks of age, male non-<br />

Cre littermates (Cre-) and Calp-2 x Cre-ERT2 (Cre+) mice were injected with tamoxifen (25 mg/kg,<br />

i.p.) daily for 5 consecutive days. After 2 weeks, Western blot analyses showed a complete depletion<br />

of calpain-2 protein in the aorta and periaortic adipose tissue from Cre+ mice compared to non-Cre<br />

littermates. Mice were fed a high fat diet (60% Kcal) for 20 weeks. After 16 weeks of diet feeding,<br />

mice were infused with AngII (1,000 ng/kg/min) by osmotic minipumps for 4 weeks. Depletion of<br />

calpain-2 had no effect on high fat diet-induced body weight gain, fat mass, glucose and insulin<br />

tolerance. Interestingly, calpain-2 depletion significantly attenuated AngII-induced expansion of exvivo<br />

maximal diameter of abdominal aortas in obese mice (Cre-: 1.4 ± 0.14; Cre+: 0.9 ± 0.04 mm;<br />

P


76<br />

Pancreatic Beta Cell Export of miR-375 to High-Density Lipoproteins is Regulated by Cellular<br />

Ion Fluxes.<br />

Leslie Sedgeman 1 • Carine Beysen, PhD 2 • Marisol Ramirez-Solano 3 • Quanhu Sheng, PhD 4 •<br />

Yan Guo, PhD 4 • Scott Turner, PhD 2 • Kasey Vickers, PhD 3<br />

1Molecular Physiology and Biophysics, Vanderbilt University • 2 Kinemed, Inc. • 3 Division of<br />

<strong>Cardiovascular</strong> Medicine, Department of Medicine, Vanderbilt University Medical Center •<br />

4Department of Cancer Biology, Vanderbilt University Medical Center<br />

Graduate Student<br />

microRNAs (miRNAs) are critical regulators of glucose metabolism and contribute to the<br />

pathogenesis of Type 2 Diabetes (T2D). Recently, we reported that high-density lipoproteins (HDL)<br />

transport and deliver functional miRNAs to recipient cells, including endothelial cells and<br />

hepatocytes. However, the mechanism of export is not understood. Since miR-375 expression in the<br />

islets is 10X greater than in other organs, we tested whether pancreatic beta cells have the ability to<br />

export miR-375 to HDL through in vitro export assays, incubating HDL with INS1 beta cells or<br />

primary human islets. Indeed, we found miR-375 to be readily exported to HDL from INS1 cells and<br />

primary islets in vitro. To determine if cholesterol transporters contribute to HDL-miR-375 export<br />

from beta cells, Abca1, Abcg1 and Scarb1 (SR-BI) were inhibited using siRNAs; however, we found<br />

that knockdown of each of these transporters failed to affect the beta cell’s ability to export miR-<br />

375 to HDL. On the other hand, inhibition of the KATP channel with tolbutamide resulted in the<br />

suppression of HDL-miR-375 export. Similarly, export of miR-375 to HDL was blunted from islets of<br />

two mouse models lacking functional KATP channels (Kir6.2 and SUR1 KO mice). Our work<br />

suggests that miR-375 export to HDL is regulated by cellular dynamics, including ion fluzes in the<br />

beta cell. We are currently investigating the relationship between HDL-miR-375 export, insulin<br />

secretion, and miRNA processing in pancreatic beta cells to further elucidate the mechanism(s)<br />

controlling HDL-miR-375 export. Collectively, results suggest that a large fraction of HDL-miRNAs<br />

originate from pancreatic beta cells and HDL-miRNAs are exported independent of cholesterol<br />

transporters.<br />

92


77<br />

The Role of ApoC-III in the immune system<br />

Alison Kohan, PhD 1 • Cayla Rodia 1<br />

1Nutritional Sciences, University of Connecticut<br />

Faculty<br />

While we know that CD4+CD25+Foxp3+ regulatory T cells (Tregs) are a powerful tool in the<br />

resolution of gut inflammation, and that their secretion of IL-10 is critical to inflammatory bowel<br />

disease (IBD) remission, there is a major gap in identifying mechanisms for increasing Tregs in the<br />

intestine. Recently, we have found that intestinal Tregs and plasma IL-10 are dramatically<br />

increased in mice overexpressing human apoC-III. These intestinal Tregs significantly protect apoC-<br />

III transgenic mice mice from experimental colitis, including weight loss, diarrhea, and TNF-α<br />

secretion. While apoC-III overexpression is protective, loss of apoC-III in apoC-III-/- mice severely<br />

impacts colitis sensitivity; more than 50% of apoC-III-/- mice die in response to dextran sodium<br />

sulfate (DSS)-colitis induction, compared to wild-type controls that all survive. Supporting our<br />

studies in these mouse models are human studies which show that both plasma and ileal apoC-III<br />

levels are reduced in patients during active IBD flare-ups. We have now determined that apoC-III<br />

acts specifically on Tregs and CD103+dendritic cells in the intestine and mesenteric lymph nodes,<br />

and that treatment of Tregs ex vivo with apoC-III-containing lipoproteins inhibits their ability to<br />

take up extracellular fatty acids. This inhibitory role of apoC-III on lipid uptake is well known, but<br />

this is the first time this role has been described in Tregs, thus defining a new and biologically<br />

important function of this apolipoprotein in the immune system. We hypothesize that a critical<br />

function of apoC-III is to regulate lipid uptake and metabolism in intestinal Tregs, which results in<br />

increased tolerogenicity in the gut.<br />

93


78<br />

Understanding inhibition of lipoprotein lipase by angiopoietin-like protein 4<br />

Aspen Gutgsell 1 • Saskia Neher, PhD 1<br />

1Biochemistry and Biophysics, UNC Chapel Hill<br />

Graduate Student<br />

More than three million cases of hypertriglyceridemia are diagnosed every year in the United<br />

States. Hypertriglyceridemia, or elevated levels of plasma triglycerides, is a major risk factor<br />

cardiovascular disease and the leading cause of death worldwide.<br />

Two major sources of plasma triglycerides are dietary fat and stored fat in adipose tissue.<br />

Triglycerides are packaged into lipoprotein particles and reahernmoved from circulation by<br />

lipoprotein lipase (LPL) in the capillaries of muscle, heart, and adipose tissue. In the absence of LPL,<br />

patients have severe hypertriglyceridemia, life-threatening pancreatitis, and fatty skin lesions. A<br />

family of proteins known as angiopoietin-like proteins (ANGPTL3, 4 and 8) temporally regulate LPL<br />

to control the delivery of fatty acids to certain tissues. More specifically, ANGPTL4 inhibits LPL in<br />

adipose tissue during periods of fasting. Recently, genome wide association and exome sequence<br />

studies identified individuals with loss of function mutations in ANGPTL4 as having a unique lipid<br />

profile that significantly decreases their risk for developing cardiovascular disease. Their profile<br />

consists of low plasma triglycerides and high levels of “good” cholesterol, commonly known as HDL.<br />

The direct relationship between LPL activity and plasma triglyceride levels lends LPL as an ideal<br />

target for triglyceride lowering therapeutics. More specifically, preserving LPL activity by blocking<br />

ANGPTL4 inhibition is hypothesized to generate a “cardio protective” lipid profile by lowering<br />

plasma triglycerides and increasing HDL cholesterol in patients with high triglycerides.<br />

However, the interaction between LPL and ANGPTL4 is poorly understood as no structural<br />

information is available. It was originally believed ANGPTL4 irreversibly inhibits LPL by<br />

dissociating it into inactive monomers. However, our group has shown that ANGPTL4<br />

noncompetitively inhibits LPL, while leaving the active dimeric structure intact. Since this<br />

discovery, little information has surfaced regarding exactly how or where ANGPTL4 and LPL<br />

interact. Therefore, our aim is to characterize the ANGPTL4/LPL interaction and generate a<br />

structural model for this complex.<br />

94


79<br />

Serum Levels of Dioxin-Like Pollutants Are Positively Associated With the Cardiometabolic<br />

Disease Risk Biomarker TMAO in Leaner Individuals<br />

Michael Petriello, PhD 1 • Richard Charnigo • Manjula Sunkara • Sony Soman • Marian Pavuk 2 •<br />

Linda Birnbaum 3 • Andrew Morris, PhD 4 • Bernhard Hennig 5<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 CDC Agency for Toxic Substances and<br />

Disease Registry • 3 NCI at NIEHS • 4 <strong>Cardiovascular</strong> Medicine, University of Kentucky • 5 Superfund<br />

<strong>Research</strong> Center, University of Kentucky<br />

Postdoc<br />

Trimethylamine N-oxide (TMAO) is a diet and gut microbiota-derived metabolite that has been<br />

linked to cardiovascular disease risk in human studies and animal models. TMAO levels show wide<br />

inter and intra individual variability in humans that can likely be accounted for by multiple factors<br />

including diet, the gut microbiota, levels of the TMAO generating liver enzyme Flavin-containing<br />

monooxygenase 3 (FMO3) and kidney function. We recently found that dioxin-like (DL)<br />

environmental pollutants increased FMO3 expression to elevate circulating diet-derived TMAO in<br />

mice, suggesting that exposure to this class of pollutants might also contribute to inter-individual<br />

variability in circulating TMAO levels in humans. To begin to explore this possibility we examined<br />

the relationship between body burden of DL pollutants (reported by serum lipid concentrations)<br />

and serum TMAO levels (n=340) in the Anniston, AL cohort, which was highly exposed to<br />

polychlorinated biphenyls (PCBs). TMAO concentrations in archived serum samples from the<br />

Anniston Community Health Survey (ACHS-II) were measured, and associations of TMAO with 28<br />

indices of pollutant body burden, including total dioxins toxic equivalent (TEQ), were quantified.<br />

Twenty-three (22 after adjustment for multiple comparisons) of the 28 indices were significantly<br />

positively associated with TMAO. Multivariate modeling revealed that total dioxins TEQ was<br />

significantly associated with TMAO among females (except at high BMIs) but not among males. Our<br />

results from this cross-sectional study indicate that exposure to DL pollutants may contribute to<br />

elevated serum TMAO levels. With the observation that dioxins were only associated with TMAO in<br />

leaner individuals, we have begun to mechanistically study the relationship between dioxin<br />

exposure, FMO3/TMAO, and cardiometabolic disease by characterizing a mouse model that<br />

develops atherosclerosis but not adipose tissue expansion. We examined the effects of PCB 126 on<br />

markers of systemic inflammation and atherosclerotic lesion size. Exposed mice exhibited<br />

significantly increased plasma cytokine levels and accelerated atherosclerotic lesion formation.<br />

More work needs to be completed to determine the role of TMAO and FMO3 in these processes<br />

(Supported in part by NIEHS/NIH grant P42ES007380).<br />

95


80<br />

Insulin signaling regulates apolipoprotein (Apo) AI secretion from hepatocytes<br />

Ailing Ji, PhD 1 • Xuebing Wang 1 • Lisa Bennett 2 • David Graf 2 • Gregory Graf, PhD 2 • Deneys van<br />

der Westhuyzen, PhD 1<br />

1<strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Pharmaceutical Sciences, University of<br />

Kentucky<br />

Staff<br />

Insulin resistance is associated with increased risk for cholesterol gallstones as well as the<br />

development of diabetic dyslipidemia in which plasma levels of HDL cholesterol are reduced. HDL<br />

is the primary cholesterol carrier in the reverse cholesterol transport (RCT) pathway, the process<br />

by cholesterol is delivered from peripheral organs to the liver for elimination in the bile. Therefore,<br />

we hypothesized that insulin signaling is a regulator of hepatobiliary cholesterol clearance from the<br />

plasma and secretion into bile. To directly test the role of insulin signaling, we utilized mice<br />

harboring insulin receptor flanked by loxP sites (IRfl/fl) in combination with adenoassociated viral<br />

vectors containing no transgene (empty) or Cre recombinase to generate control and liver insulin<br />

receptor knock out mice (LIRKO), respectively. As with previous LIRKO strains (albumin-Cre,<br />

adenoviral-Cre), LIRKO mice showed markedly reduced insulin receptor mRNA and protein in liver,<br />

but not skeletal muscle or adipose tissue as well as impaired glucose tolerance when compared to<br />

controls. LIRKO mice had increased biliary cholesterol secretion as well as increased expression of<br />

the ABCG5 ABCG8 sterol transporter, the primary mediator of biliary cholesterol secretion. Levels<br />

of SR-BI, the primary HDL receptor were unchanged as were rates of HDL clearance from plasma<br />

and selective delivery of HDL cholesterol to the liver. None-the-less, plasma HDL cholesterol and<br />

ApoAI were reduced. Despite these reductions, ApoAI protein, but not mRNA, was increased in the<br />

liver of LIRKO mice. Immunofluorescence microscopy revealed that ApoAI accumulated in<br />

membrane-bound inclusions that stained positively for markers of early, late and recycling<br />

endosomes and of lysosomes. These structures persisted in primary hepatocyte cultures where<br />

rates of ApoAI secretion into the culture medium were reduced. To determine the intracellular<br />

itinerary of ApoAI, we developed a chimera of mCherry fluorescent protein and human ApoAI.<br />

mCherry ApoAI was capable of forming nascent HDL, associated with HDL in plasma, and partially<br />

restored HDL cholesterol in ApoAI-deficient mice. However, this mCherry-ApaAI failed to colocalize<br />

with a probe for acidic compartments in live cells, suggesting that the compartment is<br />

unique or that the accumulation of ApoAI neutralizes the endosomal/lysosomal vesicles in which it<br />

accumulates. Additional studies will be required to investigate the route by which ApoAI arrives<br />

and accumulates in cells with impaired insulin signaling.<br />

96


81<br />

Scavenging reactive aldehydes with 5'-O-pentyl-pyridoxamine (PPM) improves HDL function<br />

and reduces atherosclerosis in Ldlr deficient mice<br />

Jiansheng Huang, PhD 1 • Linda Zhang, PhD 2 • Patricia Yancey, PhD 1 • Huan Tao, PhD 1 • Lei Ding 3 •<br />

YouMin Zhang 1 • John Oates, MD 4 • Venkataraman Amarnath, PhD 5 • Jackson Roberts , PhD 2 •<br />

Sean Davies, PhD 2 • MacRae Linton, MD 4<br />

1Medicine, Vanderbilt University Medical Center • 2 Pharmacology, Vanderbilt University •<br />

3Vanderbilt University Medical Center • 4 Medicine and Pharmacology, Vanderbilt University<br />

Medical Center • 5 Pathobiology, Vanderbilt University Medical Center<br />

Postdoc<br />

Background: Lipid peroxidation products impair the cholesterol efflux capacity of high-density<br />

lipoprotein (HDL) and contribute to the development of atherosclerosis. The effect of inhibition of<br />

HDL dysfunction by scavengers on HDL function and whether scavenging reactive aldehydes with<br />

PPM protects against the development of atherosclerosis was examined.<br />

Methods and Results: HDL of familial hypercholesterolemia (FH) subjects has impaired ability to<br />

promote cholesterol efflux and FH-HDL contains 5-fold more malondialdehyde crosslinks (MDA-<br />

Lys) than control HDL. In vitro studies found that the reactive aldehyde malondialdehyde (MDA)<br />

crosslinks apolipoprotein AI (apoAI) and impairs the ability of HDL to promote cholesterol efflux<br />

from Apoe-/- macrophages in a MDA dose dependent manner. Western blot analysis of apoAI<br />

revealed that the reactive aldehyde scavenger 5'-O-pentyl-pyridoxamine (PPM) abolished MDAmediated<br />

crosslinking of apoA-I in HDL (at a molar ratio of MDA to HDL of 1:5) by 80% (P


82<br />

Protease-activated Receptor 2 Deficiency Attenuates the Formation of Atherosclerosis in<br />

Mice<br />

Shannon Jones 1 • Adrien Mann 1 • Kelsey Conrad, MS 1 • Keith Saum 1 • David Hall, MS 2 •<br />

Lisa McKinney 1 • Nathan Robbins, MS 1 • Joel Thompson, PhD 3 • Abigail Peairs, PhD 2 •<br />

Michael Tranter, PhD 1 • Nigel Mackman, PhD 4 • A. Phillip Owens III, PhD 1<br />

1Internal Medicine, University of Cincinnati • 2 Nutritional Sciences, University of Cincinnati •<br />

3Endocrinology and Molecular Medicine, University of Kentucky • 4 Medicine, UNC Chapel Hill<br />

Staff<br />

Objective – Protease-activated receptor 2 (PAR2)-dependent signaling results in augmented<br />

inflammation and has been implicated in the pathogenesis of several autoimmune conditions. While<br />

PAR2 is present in coronary atherosclerotic lesions, the relevance of this finding has not been<br />

investigated in experimental models. The objective of this study was to determine the effect of<br />

PAR2 deficiency on the development of atherosclerosis.<br />

Approach and Results – PAR2 mRNA and protein expression is increased in human carotid artery<br />

and mouse aortic arch atheroma versus control carotid and aortic arch arteries, respectively. To<br />

determine the effect of PAR2 deficiency on atherosclerosis, male low density lipoprotein receptor<br />

deficient (Ldlr-/-) mice (8-12 weeks old) that were Par2+/+ or Par2-/- were fed a fat and<br />

cholesterol-enriched diet for 12 or 24 weeks. PAR2 deficiency attenuated atherosclerosis in the<br />

aortic sinus and aortic root after 12 and 24 weeks. PAR2 deficiency did not alter total plasma<br />

cholesterol concentrations or lipoprotein distributions. Bone marrow transplantation showed that<br />

PAR2 on non-hematopoietic cells contributed to atherosclerosis. PAR2 deficiency significantly<br />

attenuated levels of the chemokine monocyte chemoattractant protein 1 (MCP-1) in the circulation<br />

and macrophage content in atherosclerotic lesions. Mechanistic studies using ex vivo vascular<br />

smooth muscle cells showed that PAR2 deficiency is associated with reduced production of MCP-1<br />

mRNA and protein release into the supernatant resulting in less monocyte migration and<br />

infiltration.<br />

Conclusions – Our results indicate PAR2 deficiency is associated with attenuation of atherosclerotic<br />

inititation and reduces lesion progression by blunting MCP-1 induced monocyte infiltration.<br />

98


83<br />

Deoxysphingolipids - mediators in taxane-induced peripheral neuropathy<br />

Katrin Anne Becker, PhD 1 • Anne-Kathrin Uerschels, MD 2 • Jacek Bielawski, PhD 3 • Joan Colglazier 4<br />

• Erhard Bieberich, PhD 5 • Erich Gulbins, PhD 1 • Stefka Spassieva, PhD 5<br />

1Molecular Biology , University of Duisburg-Essen • 2 Neurosurgery, University of Duisburg-Essen •<br />

3Biochemistry and Molecular Biology , Medical University of South Carolina • 4 Medicine, Medical<br />

University of South Carolina • 5 Physiology, University of Kentucky<br />

Faculty<br />

Taxanes are chemotherapy drugs used in wide variety of cancers. However, there efficacy can be<br />

hindered by a major dose limiting side effect - peripheral neuropathy. Although, the clinical<br />

symptoms of taxane-induced peripheral neuropathy are well documented, the molecular<br />

mechanism is currently not well understood and there are no treatment options available.<br />

In our previous work, we have shown that in the plasma of breast cancer patients treated with<br />

taxane, the levels of minor class of lipids, the deoxysphingolipids, were associated with incidence<br />

and severity of neuropathy (Kramer et al, FASEB J, 2015). In our current study, we used a mouse<br />

model to test whether taxane treatment results in increased levels of deoxysphingolipids in the<br />

dorsal root ganglia and spinal cord. Mice were three times intraperitoneally injected with taxane.<br />

Lipids were extracted from the isolated ganglia and spinal cord and subjected to quantitative mass<br />

spectrometry analyses. We observed significant elevation of deoxysphingolipid levels only in the<br />

dorsal root ganglia. In addition, we compared in vitro in neuronal cultures, the toxic effect of<br />

deoxysphingosine, a deoxysphingolipid, and sphingosine, a structurally similar sphingolipid.<br />

Importantly, our in vitro data showed that only deoxysphingosine treatment resulted in<br />

morphological changes and toxicity in the neurons. Taken together our data suggest that in the<br />

dorsal root ganglia, the neurotoxic effect of the systemic taxane treatment is likely mediated by<br />

deoxysphingolipids.<br />

99


84<br />

Reduced Low-Density Lipoprotein Receptor-Related Protein-1 in Mature Mice Modestly<br />

Effects Hypercholesterolemia and Atherosclerosis<br />

Shayan Mohammadmoradi, MS 1 • Deborah A. Howatt 1 • Anju Balakrishnan 1 • Jessica<br />

J. Moorleghen 1 • Mark Graham 2 • Adam Mullick 2 • Hong Lu, PhD 1 • Alan Daugherty, PhD, DSc 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 Ionis Pharmaceuticals<br />

Graduate Student<br />

Background and Objectives:<br />

Low-density lipoprotein receptor-related protein-1 (LRP1) has been hypothesized to serve as a<br />

receptor for the removal of selected lipoprotein particles from plasma. However, mice with<br />

somatically engineered mutation of LRP1 have not provided a clear understanding of the specific<br />

lipoprotiens that are regulated by LRP1. Therefore, the aim of this study was to reduce LRP1 using<br />

antisense oligomers in mature mice to determine effects on lipoprotein metabolism and<br />

atherosclerosis.<br />

Methods and Results:<br />

LRP1 antisense oligonucleotide (ASO; 50 mg/kg, injected once per week) or its control ASO was<br />

administered subcutaneously to 8-week old male low-density lipoprotein (LDL) receptor deficient<br />

mice (n=10/each group). All groups were fed a saturated fat-enriched diet for 8 weeks started 1<br />

week after the first injection of ASOs. There was no difference in body weight between the two<br />

groups. Profound reduction of LRP1 was confirmed by qPCR and Western blotting. Whole body<br />

inhibition of LRP1 elicited a modestly increased total plasma cholesterol compared to its control<br />

group. Size exclusive chromatography analyses demonstrated the increased cholesterol was due to<br />

increased VLDL and LDL-cholesterol. Despite augmented hypercholesterolemia, whole body<br />

inhibition of LRP1 did not increase atherosclerotic lesion size. LRP1 was also reduced in a<br />

hepatocyte-specific manner by administration of an LRP1 ASO coupled with GalNac to target the<br />

asialofeutin receptor. LDL receptor deficient mice were injected with GalNAc LRP1 ASO or its<br />

control ASO (5 mg/kg/week). Hepatic-specific inhibition of LRP1 did not change plasma cholesterol<br />

concentration, lipoprotein distribution and atherosclerosis.<br />

Conclusion:<br />

Profound reductions of LRP1 in mature mice modestly increased hypercholesterolemia and had no<br />

effect on atherosclerosis in LDL receptor deficient mice.<br />

100


85<br />

Oxidized neutral lipid lipolysis as a novel regulator of insulin signaling during acute stress<br />

Katelyn Ahern 1 • Garrett Mullins, PhD 1 • Vidisha Raje, PhD 1 • Vlad Serbulea 1 •<br />

Norbert Leitinger, PhD 1 • Thurl Harris, PhD 1<br />

1Pharmacology, University of Virginia<br />

Graduate Student<br />

The acute stress response following an injury or surgery often results in systemic insulin resistance<br />

(IR) and hyperglycemia which can lead to increased morbidity and mortality. Post-operative IR is<br />

downstream of stress hormones such as catecholamines, but the underlying mechanisms driving IR<br />

are unknown, thus limiting therapeutic development. We have previously demonstrated that β-<br />

adrenergic stimulation of adipocytes causes inhibition of the mTOR complexes and leads to the<br />

development of IR in a lipolysis-dependent manner. Therefore, we hypothesize that a product of<br />

lipolysis is responsible. We find that lipid extracts isolated from forskolin-stimulated 3T3-L1<br />

adipocytes inhibit the activity of the mTOR complexes in vitro. However, when tested, “traditional”<br />

products of lipolysis had no effect on mTOR complexes. Interestingly, stimulating oxidation of fatty<br />

acids using tert-butyl hydroperoxide further exacerbates mTOR inhibition, while antioxidant<br />

treatment reverses this effect, suggesting that the active species is an oxidized fatty acid. In fact,<br />

incubation of mTOR complex with in vitro auto-oxidized fatty acids is sufficient to inhibit kinase<br />

activity. These findings reveal a previously unrecognized mechanism of oxidized fatty acid signaling<br />

and mTOR complex regulation in the development of peripheral IR during acute stress. Our future<br />

work will focus on identifying these species in vivo using our novel targeted liquid<br />

chromatography-mass spectrometry method and characterizing their physiological role in<br />

response to stress-inducing events known to stimulate reactive oxygen species production.<br />

101


86<br />

Pharmacological inhibition of HuR improves survival and reduces adverse cardiac<br />

remodeling following left-ventricular pressure overload<br />

Sarah Anthony 1 • Xiaoqing Wu, PhD 2 • Lisa Green 1 • Michelle Nieman 3 • John Lorenz, PhD 3 •<br />

Jack Rubinstein, MD 1 • Liang Xu, PhD 2 • Michael Tranter, PhD 1 • Burns Blaxall, PhD 4<br />

1Division of <strong>Cardiovascular</strong> Health and Disease, University of Cincinnati • 2 Molecular Biosciences,<br />

University of Kansas • 3 Pharmacology and Systems Physiology, University of Cincinnati •<br />

4Department of Pediatrics, Division of Molecular <strong>Cardiovascular</strong> Biology, Heart Institute, Cincinnati<br />

Children's Hospital<br />

Staff<br />

Human antigen R (HuR) is a widely expressed RNA binding protein that has been implicated in<br />

numerous human diseases including cancer, neurological disorders, and cardiovascular<br />

disease. We have previously shown that HuR is both necessary and sufficient for induction of<br />

hypertrophic signaling pathways in isolated primary myocytes. In addition, data from our lab is the<br />

first to suggest that HuR expression and activation is increased in failing human hearts. To<br />

determine the role of HuR in hypertrophic signaling in vivo, we created an inducible<br />

cardiomyocyte-specific HuR deletion mouse, and showed that genetic deletion of HuR reduces<br />

pathology using a transverse aortic constriction (TAC) model of pressure-overload-induced<br />

hypertrophy, adverse cardiac remodeling, and heart failure. In this work, we sought to recapitulate<br />

this reduction in pathology using KH-3, a novel pharmacological inhibitor of HuR, to determine the<br />

translational potential of HuR inhibition as a viable therapeutic target.<br />

Twenty wild-type mice were randomized to either vehicle or KH-3 at four weeks post-TAC, a timepoint<br />

consistent with substantial development of cardiac hypertrophy, and monitored via serial<br />

echocardiography for a further seven weeks. Our results show that treatment with KH-3 increased<br />

survival relative to vehicle controls. In addition, as compared with vehicle, KH-3 treatment<br />

significantly abated the continued progression of left ventricular (LV) hypertrophy. This was<br />

accompanied by a significant preservation of LV ejection fraction and reduction in LV chamber<br />

dilation in KH-3 treated mice. Importantly, chronic KH-3 treatment had no effects on systemic<br />

blood pressure and no observable adverse reactions. In conclusion, these results suggest that<br />

inhibition of HuR is a promising therapeutic approach to treat pathological LV hypertrophy.<br />

102


87<br />

Perioperative high density lipoprotein particle changes and the risk of acute kidney injury<br />

after cardiac surgery<br />

Loren Smith, MD, PhD 1 • Derek Smith, PhD 2 • Alan Remaley, MD, PhD 3 • MacRae Linton, MD 4 •<br />

Frederic Billings IV, MD 5<br />

1Anesthesiology, Vanderbilt University Medical Center • 2 Biostatistics, Vanderbilt University<br />

Medical Center • 3 National Heart, Lung, and Blood Institute, National Institutes of Health •<br />

4Medicine and Pharmacology, Vanderbilt University Medical Center • 5 Anesthesiology and<br />

Medicine, Vanderbilt University Medical Center<br />

Faculty<br />

Acute kidney injury (AKI) after cardiac surgery occurs in up to 30% of patients and increases the<br />

risk of postoperative myocardial infarction and death. No effective treatments exist. Increased<br />

intraoperative oxidative stress independently predicts AKI after cardiac surgery. High density<br />

lipoproteins (HDL) have anti-oxidant capacity. We hypothesize that perioperative HDL cholesterol<br />

concentration (HDL-C), HDL particle concentration (HDL-P) and HDL composition are associated<br />

with the risk of postoperative AKI.<br />

We analyzed data from a prospective, 393-subject trial of perioperative atorvastatin to prevent AKI<br />

after cardiac surgery. Statin-using patients were randomized to placebo or 80mg atorvastatin the<br />

morning of surgery and 40mg on postoperative day 1. Stain-naïve patients were randomized to<br />

placebo or 80mg the day prior to surgery and 40mg daily thereafter during hospitalization. The<br />

associations between 1) HDL-C, 2) small HDL particle concentration, and 3) the change in HDL-P<br />

from anesthetic induction to postoperative day two with maximum serum creatinine change from<br />

baseline in the first 48 postoperative hours were assessed using two-component latent variable<br />

mixture models adjusted for known AKI risk factors. Regression analyses assessed interactions of<br />

chronic statin use, perioperative atorvastatin treatment, and HDL-C on AKI risk. We quantified HDL<br />

particle size by NMR Lipoprofile test in 90 subjects. HDL-C and HDL-P change over time were<br />

assessed with mixed effects models adjusted for AKI risk factors. We quantified myeloperoxidase<br />

(MPO) activity of apolipoprotein B-depleted serum in 30 subjects using a bioluminescence assay.<br />

A higher preoperative HDL-C was independently associated with a decreased postoperative serum<br />

creatinine change (p=0.02). The association between a high HDL-C and an attenuated increase in<br />

serum creatinine was strongest in chronic statin-using patients (p=0.008) and was enhanced with<br />

perioperative atorvastatin treatment (p=0.004) and increasing chronic statin dose (p=0.003). HDL-<br />

C did not change during the perioperative period (p=0.60), however, HDL-P decreased (p


88<br />

The Effects of Hypercholesterolemia on Wound Healing and Endothelial Angiogenic<br />

Properties<br />

Yedida Bogachkov 1 • Lin Chen, MD, PhD 2 • Myung-Jin Oh, PhD 3 • Luisa A. DiPietro, PhD 2 •<br />

Irena Levitan, PhD 4<br />

1Pharmacology, University of Illinois at Chicago • 2 Periodontics, University of Illinois at Chicago •<br />

3Medicine, University of Chicago • 4 Pulmonary, Critical Care, Sleep and Allergy, University of Illinois<br />

at Chicago<br />

Graduate Student<br />

Nearly 31 million adults in the US have elevated total cholesterol levels over 240 mg/dL, and almost<br />

32% of US adults have LDL cholesterol levels of 200mg/dL or above. Our study focuses on the<br />

impact of dyslipidemia on wound healing and wound angiogenesis. Using ApoE-/- mice, a known<br />

dyslipidemic model and a skin punch biopsy wound healing assay, we show that ApoE -/- mice<br />

show significantly delayed wound closure on days 2-7 post-wounding compared to control mice.<br />

These same ApoE-/- also display significantly decreased angiogenesis on days 10 and 14 post<br />

wounding, based on PECAM staining for endothelial cells, indicative of endothelial cell infiltration of<br />

the wound bed and new blood vessel growth. Furthermore, macrophage infiltration is also reduced.<br />

This significant suppression of wound angiogenesis is also seen when LDL is directly applied to the<br />

wounds via subcutaneous injections on C57BL6 mice. Additionally, using a matrigel plug assay, we<br />

show significantly suppressed angiogenesis in C57BL6 mice fed a Western Diet for 40 weeks. These<br />

results utilize an Isolectin B4 probe, which is indicative of endothelial cell infiltration into the<br />

matrigel plug and new blood vessel growth. Finally, in vitro studies on human aortic endothelial<br />

cells were pursued showing LDL significantly decreases endothelial cell proliferation, whereas its<br />

oxidized form, oxLDL, shows an increase in proliferation. In sum, we have shown in vivo that<br />

hypercholesterolemic mice have a decreased angiogenic potential, and in vitro, excess LDL leads to<br />

a decrease in angiogenic potential of aortic endothelial cells.<br />

104


89<br />

Coarse-Grained Molecular Dynamics Simulations of Kir2.2 Interactions with an Ensemble of<br />

Cholesterol Molecules<br />

Nicolas Barbera, MS 1 • Manuela Ayee, PhD 1 • Belinda Akpa, PhD 2 • Irena Levitan, PhD 3<br />

1Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at<br />

Chicago • 2 Department of Molecular Biomedical Sciences, North Carolina State University •<br />

3Department of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of<br />

Illinois at Chicago<br />

Graduate Student<br />

Hypercholesterolemia, elevated plasma levels of cholesterol, is a major risk factor in the<br />

development of atherosclerosis. Our previous studies have shown that inwardly rectifying K+ (Kir)<br />

channels, which play an important role in endothelial function, are suppressed by enriching cells<br />

with cholesterol. Additionally, earlier work done by our group and others has shown that<br />

cholesterol regulates Kir2 channels, a sub-family of Kir channels expressed in endothelial cells,<br />

through direct interactions at non-annular interaction sites. However, while a putative binding site<br />

has been identified, the dynamics of the binding process and cholesterol’s structural effect on the<br />

protein remain poorly understood. To address these questions, we used coarse grained molecular<br />

dynamics simulations of Kir2.2, a subfamily of Kir2, in model membranes containing cholesterol<br />

and POPC to interrogate their molecular interactions at the microsecond timescale. Our simulations<br />

show that rather than single ligand-channel binding, interactions between cholesterol and the<br />

channel are both complex and numerous, with an average of 15-20 cholesterol molecules<br />

interacting with the protein at any given time. These interactions occur at a range of timescales and<br />

at distinct annular and non-annular sites on the surface of the protein. Additionally, we observed<br />

spontaneous diffusion between these sites and between the protein surface and the surrounding<br />

membrane. At present, we are exploring the functional significance of these various interactions<br />

and the impact of this collective action on the structure-function relationships governing Kir2<br />

channel activity.<br />

105


90<br />

Reduced HDL in mice overexpressing SR-BI is associated with alterations in the acute<br />

inflammatory response to endotoxemia<br />

Yanzhang Li, PhD 1 • Ailing Ji, PhD 2 • Xuebing Wang 2 • Andrea Trumbauer 2 • Maria C. de Beer, PhD 3<br />

• Frederick C. de Beer, MD 4 • Nancy R. Webb, PhD 5<br />

1IM-Endocrinology, University of Kentucky • 2 <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of<br />

Kentucky • 3 Physiology, University of Kentucky • 4 Internal Medicine, University of Kentucky •<br />

5Pharmacology and Nutritional Sciences, University of Kentucky<br />

Faculty<br />

Objectives: Serum amyloid A (SAA) is an acute phase protein (APP) produced mainly by the liver<br />

during an acute phase response (APR). During the APR, virtually all of SAA circulating in the blood<br />

is associated with HDL. SR-BI is an HDL receptor and also can bind SAA. Previous reports showed<br />

that in SR-BI transgenic mice, hepatic uptake of SAA is increased, and this uptake is involved in the<br />

pro-inflammatory effects of SAA. Whether SR-BI regulates SAA expression in response to the<br />

inflammatory stimulation is not yet investigated.<br />

Methods/Results: Ten week-old male C57BL/6 mice were administered 1x1011 particles of a<br />

replication-defective adenoviral vector expressing mouse SR-BI (AdSR-BI) or an adenoviral vector<br />

containing no transgene (Adnull) as control. At 72h after adenovirus infusion, the mice were<br />

injected i.p. with 1mg /kg body weight LPS. Plasma and tissues were collected at selected time<br />

points after LPS injection. As expected, overexpression of SR-BI produced a dramatic reduction in<br />

HDL-C (56.52 ± 2.338 mg/dL vs 2.08 ± 1.555 mg/dL for Adnull versus AdSR-BI). Plasma levels of<br />

inflammatory cytokine IL-1b, TNFa and IL-6 were robustly higher in AdSR-BI-injected mice<br />

compared to control mice. Lympohcyte numbers were also signicantly higher in AdSR-BI-injected<br />

mice compared to control mice 12h after LPS injection. In contrast, SAA in plasma was much lower<br />

in AdSR-BI-injected mice compared to control mice. Before LPS injection, SAA could only be<br />

detected at very low levels in the plasma by ELISA (20.7±8.3 ug/ml). LPS induced a robust increase<br />

in plasma SAA levels as early as 2h post-LPS treatment in Adnull-treated mice (1100.0±108.7<br />

ug/ml). Notably, increases in plasma SAA were significantly lower in AdSR-BI-treated mice<br />

(122.7±9.5 ug/ml) 2h after LPS injection. At 12h after LPS injection, plasma levels of SAA were 10-<br />

fold lower in AdSR-BI-treated mice compared to control mice (12.9±0.24 mg/ml vs 1.2±0.21<br />

mg/ml). The results from western blot and real-time RT-PCR showed that hepatic SAA expression<br />

was significantly decreased in the liver of SR-BI overexpressed mice but significantly increased in<br />

hepatocytes of SR-BI knock out mice compared to that of control mice.<br />

Conclusions: Our results demonstrate that decreased levels of HDL in SR-BI-overexpressing mice<br />

are associated with alterations in acute inflammatory responses. Future studies will investigate the<br />

relationship between reduced SAA and increased inflammatory cytokines in mice with increased<br />

hepatic SR-BI overexpression.<br />

106


91<br />

A patient with very high plasma level of high-density lipoprotein cholesterol (HDLc) and<br />

sudden cardiac arrest<br />

Wenliang Song, MD 1 • Ginger Milne, PhD 2 • John Fahrenholz, MD 3 • John McPherson, MD 1 •<br />

John Oates, MD 4 • Dan Roden, MD 1 • MacRae Linton, MD 1<br />

1Cardiology, Vanderbilt University Medical Center • 2 Clinical Pharmacology, Vanderbilt University •<br />

3Medicine, Vanderbilt University Medical Center • 4 Medicine, Vanderbilt University<br />

Postdoc<br />

Synopsis:<br />

A 58-year-old female with plasma HDLc of 110-150 mg/dL suffers from a very debilitating facial<br />

flushing for the past several years. She also had two episodes of sudden cardiac arrests.<br />

Purpose:<br />

To find a pathological condition that can explain the constellation of symptoms this patient has,<br />

which may provide important insights of HDL metabolism<br />

Methods:<br />

Extensive clinical work-ups to evaluate her constellation of symptoms and basic laboratory<br />

experiments including HPLC/MS/MS to evaluate specific biomarkers for rare orphan diseases<br />

Results:<br />

This patient's coronary angiogram was normal. However, acetylcholine challenge produced<br />

significant coronary spasm. Bone marrow biopsy excluded systemic mastocytosis. Urinary<br />

prostaglandin D2 metabolites increased after flushing attacks, which suggests the patient has a<br />

condition of mast cell activation syndrome. Her clinical constellation of symptoms mimic the<br />

niacin's pharmacological effect. Genetic investigation may shed lights on the mechanism of HDL<br />

metabolism and niacin's therapeutic effect.<br />

Conclusions:<br />

Isolated mast cell activation syndrome may cause coronary spasm. Rare gene mutation may be<br />

responsible for her condition. Future genetics investigation may shed lights on the mechanism of<br />

HDL metabolism.<br />

107


92<br />

Human Antigen R (HuR) Regulates Structure and Function of Brown Adipose Tissue<br />

Lindsey Lanzillotta 1 • Zach Taylor 1 • Kaila Yamamoto 1 • Sarah Anthony 1 • Shannon Jones 1 •<br />

George Yoshida 1 • A. Phillip Owens III, PhD 1 • Michael Tranter, PhD 1<br />

1Internal Medicine, University of Cincinnati<br />

Graduate Student<br />

Human antigen R (HuR) is an RNA binding protein widely expressed throughout the body, including<br />

in both white (WAT) and brown (BAT) adipose tissue. Recent work from our lab has shown that<br />

adipocyte-specific HuR knockout (adipo-HuR-/-) mice gain less weight following a high fat diet<br />

(HFD) compared to wild type (WT) controls. In this study, we focused on the role of HuR deletion<br />

on the function of BAT, which mediates non-shivering thermogenesis.<br />

Histological analysis revealed that, while the BAT of the chow fed adipo-HuR-/- mice appeared<br />

normal, the BAT of the HFD fed adipo-HuR-/- mice appears less dense with a cell size that more<br />

closely resembles WAT. Upon further examination of BAT function, our results show that, when<br />

subjected to cold stress (4C), adipo-HuR-/- mice are less cold tolerant compared to their WT<br />

counterparts . We also show that, compared to the WT mice, adipo-HuR-/- mice have decreased<br />

mitochondrial density and expression of uncoupling protein-1 (UCP-1) in their BAT. This may be<br />

caused by a HuR-dependent decrease in expression of peroxisome proliferator-activated receptor<br />

gamma coactivator 1 alpha (PGC-1a), which plays a key role in mitochondrial biogenesis and is<br />

upregulated during exposure to cold (4C).<br />

In conclusion, our results indicate that HuR regulates both the structure and function of BAT, at<br />

least in part through modulation of PGC-1a mRNA expression.<br />

Support or Funding Information:<br />

This work was supported by a University of Cincinnati Heart, Lung, and Vascular Institute Near<br />

Horizons Grant (MT, APO).<br />

108


93<br />

Impact of miR-33 antagonism on atherosclerotic plaque size and cholesterol content in<br />

nonhuman primates<br />

Tong Li, MD 1 • Lei Cai, PhD 1 • Sierra Paxton 1 • Courtney Burkett 1 • Peter Hecker, MS 1 •<br />

Ryan Temel, PhD 1<br />

1CVRC, University of Kentucky<br />

Graduate Student<br />

Introduction: Elevated LDL cholesterol (LDL-C) is a major risk factor for coronary heart disease<br />

(CHD). Statins are used to lower LDL-C and CHD risk but do not completely eliminate CHD events<br />

caused by atherosclerotic lesion rupture. By stimulating macrophage cholesterol efflux and<br />

promoting anti-inflammatory macrophage polarization, antagonism of microRNA-33a (miR-33a) in<br />

mice reduces the cholesterol content and size of atherosclerotic lesions. Mouse studies have limited<br />

translational value since mice do not develop coronary artery atherosclerosis and express only one<br />

of the two miR-33 family members found in humans. Since nonhuman primates (NHPs) have miR-<br />

33a and miR-33b and develop coronary artery atherosclerosis, NHPs are the best preclinical model<br />

for determining the therapeutic potential of miR-33 antagonism. We hypothesize that NHPs treated<br />

with miR-33 antagonist will have decreased plaque size and cholesterol content.<br />

Methods: Male cynomolgus monkeys (n=36) were fed for 20 months a high fat/high cholesterol<br />

diet, which caused severe hypercholesterolemia. At the end of the 20-month progression phase, a<br />

subset of monkeys (n=12) were euthanized to collect tissues. The remaining monkeys were<br />

switched to a cholesterol-lowering “chow” diet and treated with either vehicle (n=12) or anti-miR-<br />

33 (n=12) for 6 months. Formalin-fixed right coronary arteries (RCA) were split into five ~3 mm<br />

sections, paraffin embedded, and cut into 5 µm slices. Lesion area, defined as the region between<br />

the lumen and internal elastic lamina, was measured for each RCA section and then averaged for<br />

each animal. Cholesterol was extracted from a section of the fixed thoracic aorta and the free and<br />

total cholesterol levels were determined by GC-FID. Esterified cholesterol (EC) = total cholesterol –<br />

free cholesterol (FC).<br />

Results: No significant difference among the progression, vehicle, and anti-miR-33 groups were<br />

observed for RCA lesion area (P=0.60) and thoracic aorta FC (P=0.24). Thoracic aorta EC was<br />

significantly increased in the progression versus the regression groups (P


94<br />

Impact of miR-33 antagonism on coronary artery atherosclerotic plaque composition in<br />

nonhuman primates<br />

Lei Cai, PhD 1 • Tong Li, MD 1 • Sierra Paxton 1 • Courtney Burkett 1 • Peter Hecker, MS 1 • Ryan Temel<br />

, PhD 1<br />

1CVRC, University of Kentucky<br />

Staff<br />

Introduction: Elevated LDL cholesterol (LDL-C) is a major risk factor for coronary heart disease<br />

(CHD). Statins are used to lower LDL-C and CHD risk but do not completely eliminate CHD events<br />

caused by atherosclerotic lesion rupture. By stimulating macrophage cholesterol efflux and<br />

promoting anti-inflammatory macrophage polarization, antagonism of microRNA-33a (miR-33a) in<br />

mice causes atherosclerotic lesions to acquire a more stable composition. Mouse studies have<br />

limited translational value since mice do not develop coronary artery atherosclerosis and express<br />

only one of the two miR-33 family members found in humans. Since nonhuman primates (NHPs)<br />

have miR-33a and miR-33b and develop coronary artery atherosclerosis, NHPs are the best<br />

preclinical model for determining the therapeutic potential of miR-33 antagonism. We hypothesize<br />

that miR-33a/b antagonism will stabilize coronary artery atherosclerotic plaques of NHPs.<br />

Methods and Results: Male cynomolgus monkeys (n=36) were fed for 20 months a high fat/high<br />

cholesterol diet, which caused severe hypercholesterolemia. At the end of the 20-month<br />

progression phase, the hearts from 12 animals were perfused with formalin under physiological to<br />

preserve the structure of the coronary arteries. The remaining monkeys were switched to a<br />

cholesterol-lowering “chow” diet and treated with either vehicle (n=12) or anti-miR-33 (n=12) for<br />

6 months. LDL-C for both treatment groups was rapidly reduced by the chow diet and returned to<br />

baseline levels by the 3rd month of the regression phase. The anti-miR-33 versus the vehicle group<br />

had a sustained and significant elevation in HDL-C that was linked to a significant increase in<br />

hepatic ABCA1, a miR-33 target. Following dissection and paraffin embedding of the right coronary<br />

arteries (RCA), 5 µm slices were analyzed by histology and immunohistochemistry (IHC). The RCA<br />

atherosclerotic lesions from both the progression and regression groups were characterized by<br />

intimal smooth muscle cell proliferation, collagen deposition, elastin degradation, and medial layer<br />

destruction. While necrotic cores were a common feature, there was a minimal amount of plaque<br />

calcification. Macrophages were found at high levels in the progression group lesions but were<br />

almost absent from the plaques of both the anti-miR-33 and vehicle groups.<br />

Conclusions and Future Directions: The qualitative histology and IHC results show that the<br />

monkeys developed RCA atherosclerotic plaques similar to early fibroatheromas observed in<br />

humans. By quantifying the area occupied by the various plaque components, we will determine<br />

whether antagonism of miR-33a/b allowed the lesions to attain a more stable composition. In<br />

addition, to determine whether anti-miR-33 changes the amount or type of macrophages in lesions,<br />

we will analyze coronary arteries from monkeys subjected to 6 weeks, as opposed to 6 months, of<br />

regression.<br />

110


95<br />

Targeting of HB-EGF against hypertension and renal damage<br />

Lihua Yang, MS 1 • Seonwook Kim 1 • Debra Rateri 1 • Richard Lee, PhD 2 • Mark Graham, PhD 2 •<br />

Sangderk Lee, PhD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 <strong>Cardiovascular</strong> Antisense Drug<br />

Discovery Group, Ionis Pharmaceuticals<br />

Staff<br />

Study goal: Previous reports suggested that the heparin binding EGF-like growth factor (HB-EGF),<br />

which is an EGFR ligand, is positively involved in the development of renal disease. In this study, we<br />

tested the effects of the HB-EGF targeting using antisense oligonucleotide (ASO) administration on<br />

the blood pressure and renal damage induced by AngII infusion in mouse model systems.<br />

Experimental design and results: To test the effects of the HB-EGF ASO administration on the AngIIinduced<br />

hypertension, C57BL/6 mice (male, 10 weeks of age) were pretreated with control and HB-<br />

EGF ASO for 2 weeks and cotreated with AngII infusion (1,000ng/min/kg) for additional 4 weeks.<br />

We monitored blood pressure changes during 6 weeks using standard tail-cuff procedure. We<br />

observed that the HB-EGF ASO administration significantly downregulated basal and AngII-induced<br />

blood pressure in the system. The HB-EGF targeting also reduced the kidney size. To test the effects<br />

of the HB-EGF targeting on the renal damage, the LDLR KO mice (male, 16 weeks of age) were<br />

pretreated with control and HB-EGF ASO and cotreated with high fat diet (HFD; 42% calorie from<br />

fat, 0.2% cholesterol) and AngII-infusion (1,000ng/min/kg) for additional 4 weeks. At the<br />

termination step, we compared plasma creatinine and BUN levels as markers of the status of the<br />

renal damage. The result showed that the HB-EGF ASO administration effectively protected against<br />

HFD and AngII-induced renal damage in the mouse model system.<br />

Conclusion: These results suggested that the HB-EGF signaling positively involved in regulating<br />

blood pressure and renal damage. The targeting of the HB-EGF signaling might be an approach to<br />

delay the development of the hypertension associated with renal damage.<br />

111


96<br />

HB-EGF is a Key Positive Regulator of Hepatic VLDL Secretion<br />

Seonwook Kim 1 • Lihua Yang, MS 1 • Debra Rateri 1 • Ryan Temel, PhD 1 • Richard Lee, PhD 2 •<br />

Mark Graham, PhD 2 • Sangderk Lee, PhD 1<br />

1Saha <strong>Cardiovascular</strong> <strong>Research</strong> Center, University of Kentucky • 2 <strong>Cardiovascular</strong> Antisense Drug<br />

Discovery Group, Ionis Pharmaceuticals<br />

Staff<br />

Study goal: Unbalanced hepatic VLDL production (assembly/secretion) is a risk factor for the<br />

development of hypertriglyceridemia or non-alcoholic fatty liver disease (NAFLD) under metabolic<br />

stress conditions like metabolic syndrome. Previous reports showed that the circulatory heparinbinding<br />

EGF-like growth factor (HB-EGF), which is a ligand of EGFR, is correlated with cholesterol<br />

level and risk of coronary artery disease in human. From these previous data, we tested the<br />

hypothesis that the HB-EGF signaling is a positive regulator of VLDL production in the liver.<br />

Experimental procedure and results: In Hep-G2 cells, the recombinant HB-EGF induced increase of<br />

the apoB secretion, which is an essential component of VLDL particle. In C57BL/6 mice, the<br />

administration of recombinant HB-EGF increased hepatic VLDL secretion; in contrast, the HB-EGF<br />

antisense oligonucleotide (ASO) administration or the tail-vein injection of EGFR blocker BIBX1382<br />

induced significant suppressions of the hepatic VLDL secretion. The HB-EGF ASO administration<br />

effectively downregulated circulatory lipid levels (TG and cholesterol) associated with VLDL<br />

particles in multiple mouse strains (C57BL/6, LDLR KO, and apoE KO). At the same time, the<br />

targeting induced accumulation of neutral lipids in the liver, specifically, TG and cholesterol ester.<br />

Conclusion: These results indicate that the HB-EGF signaling positively regulates VLDL secretion in<br />

the liver under normal and metabolic stress condition. Future study of the interaction with insulin<br />

signaling for the regulation would be interesting in understand the pathology of metabolic<br />

symptom.<br />

112


97<br />

Anti-ApoA-I antibodies induced using an epitope-specific immunostimulatory liposomal<br />

formulation exacerbate atherosclerosis in dyslipidemic mice<br />

David Henson 1 • Robert Kline IV, MS 1 • Vincent Venditto, PhD 1<br />

1Pharmaceutical Sciences, University of Kentucky<br />

Graduate Student<br />

Autoantibodies targeting apolipoprotein A-I (ApoA-I) have been identified in patients with chronic<br />

inflammatory diseases including rheumatoid arthritis, lupus and obesity and correlate with<br />

cardiovascular disease progression. Although correlated, the exact role of these antibodies has not<br />

been fully elucidated. Induction of antibodies in mice through immunization, rather than passive<br />

administration of antibodies derived from other species, offers a unique opportunity to explore the<br />

impact of anti-ApoA-I antibodies in the context of atherosclerosis. Furthermore, the ability to<br />

modulate epitope-specific immune responses offers a strategy to study the impact of antibody<br />

responses toward specific domains within the full protein. To achieve these objectives, we prepared<br />

an immunostimulatory liposomal formulation containing peptides derived from the LCAT domain<br />

of ApoA-I. We first determined that mice immunized with the complete formulation induce robust<br />

antibody responses toward the epitope, as well as the full-length protein. These data suggest that<br />

antibody responses toward ApoA-I are either not controlled by immunological tolerance<br />

mechanisms or our formulation was capable of breaking tolerance. Although successful at inducing<br />

a robust immune response, the antibodies alone failed to induce atherosclerosis in wild-type mice.<br />

We then studied the role of antibodies in the context of dyslipidemia utilizing the AAV-PCSK9 gainof-function<br />

mutant and western diet. After establishment of dyslipidemia, mice were immunized<br />

with the immunostimulatory liposomal formulations. Once again, mice immunized with the<br />

complete formulation achieved robust antibody responses, which persisted for 150 days.<br />

Furthermore, mice immunized with the complete formulation had a statistically significant<br />

elevation in atherosclerosis over control mice. These data highlight our ability to modulate the anti-<br />

ApoA-I antibody response using epitope-specific liposomal formulations and provides a platform to<br />

study the role of these antibodies in an immunologically intact system.<br />

This work was supported by a pilot grant through the Center for <strong>Research</strong> in Obesity &<br />

<strong>Cardiovascular</strong> Disease COBRE, NIH (P20GM103527) and a Scientist Development Grant from the<br />

American Heart Association (17SDG32670001). DH is supported by a UK Center for Clinical and<br />

Translational Science training grant from the National Center for Advancing Translational Sciences,<br />

NIH (TL1TR001996).<br />

113


98<br />

HDL-miR-223 Communication Pathway in vivo.<br />

Carrie Wiese 1 • Leslie Roteta 1 • Ryan Allen, PhD 2 • Wanying Zhu 2 • Kasey Vickers, PhD 2<br />

1Molecular Physiology & Biophysics, Vanderbilt University • 2 <strong>Cardiovascular</strong> Medicine, Vanderbilt<br />

University Medical Center<br />

Graduate Student<br />

High-density lipoproteins (HDL) stably transport microRNAs (miRNAs) through the blood and<br />

facilitate a HDL-miRNA communication pathway. Previously, we demonstrated that macrophages<br />

and other myeloid cells export miR-223 to HDL in vitro. Furthermore, HDL-miRNAs, including miR-<br />

223, are delivered to recipient human coronary artery endothelial cells (HCAECs) where miR-223 is<br />

not transcribed. Upon transfer of miR-223 to endothelial cells, the validated miR-223 target<br />

intracellular adhesion molecule 1 (Icam-1) expression is significantly suppressed. While HDLmiRNA<br />

transfer and cellular gene regulation have been demonstrated in vitro, intercellular<br />

communication has not been established in vivo. We utilized bone marrow transplantation between<br />

C57/B6J (WT) and Mir223-/- mice to define the physiological role of HDL-miRNA pathway in<br />

regulating cellular gene expression. To restore the HDL-miR-223 communication pathway within<br />

Mir223-/- mice, we transplanted WT bone marrow into lethally irradiated Mir223-/- mice resulting<br />

in a significant increase in HDL-miR-223 levels. Subsequently, a significant increase in miR-223 was<br />

identified in recipient tissues including whole liver, hepatocyte isolates, and aortic endothelium.<br />

Conversely, HDL-miR-223 pathway was depleted by transplanting Mir223-/- bone marrow into<br />

lethally irradiated WT mice, which resulted in a significant reduction of miR-223 on HDL. The<br />

reduction in HDL-miR-223 levels correlated with reduced miR-223 levels in recipient cells<br />

including endothelial and hepatocyte. Furthermore, altering miR-223 levels in endothelial cells and<br />

hepatocytes resulted in altered mRNA levels of putative targets, which we have validated as miR-<br />

223 targets. In conclusion, myeloid cells export miR-223 to extracellular carriers such as HDL,<br />

which results in delivery of miR-223 to recipient cells where it regulates gene expression.<br />

114


99<br />

Dynamic hepatic oxidized phospholipid composition promotes non-alcoholic fatty liver<br />

disease progression<br />

Clint Upchurch 1 • Vlad Serbulea 1 • Norbert Leitinger, PhD 1<br />

1Pharmacology, University of Virginia<br />

Graduate Student<br />

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of metabolic syndrome, affects<br />

25% of individuals within the United States. NAFLD is a progressive pathology initiating with<br />

accumulation of fat within the liver (hepatic steatosis) followed by inflammation (steatohepatitis)<br />

and liver fibrosis. Currently, drivers of NAFLD progression are poorly understood. We propose that<br />

oxidized phospholipids (OxPLs) within the liver promote NAFLD pathophysiology. We developed a<br />

liquid chromatography-mass spectrometry method to quantify oxidation products of 1-palmitoyl-2-<br />

arachidonoyl-sn-glycero-3-phosphatidylcholine (PAPC) in liver tissue and observed an increase in<br />

full-length PAPC oxidation products (OxPAPC) in mice fed a high fat diet (HFD). HFD-fed mice<br />

exhibit extensive hepatic steatosis, the first stage of NAFLD. Separately, using<br />

immunohistochemistry we observed an increase in liver OxPLs in mice treated with carbon<br />

tetrachloride, a model of liver damage. Furthermore, hepatic stellate cells, the major contributor to<br />

fibrosis, show an increase in fibrotic gene expression in response to treatment with OxPAPC. Taken<br />

together, OxPLs play a role in stellate cell over-activation in response to liver damage and<br />

subsequent fibrosis.<br />

115


100<br />

Short-Term Exercise Training Differently Modifies Aspects of HDL Function in Lean, Obese<br />

and Diabetic Subjects<br />

Lin Zhu, PhD 1 • Nicolas Musi, MD 2 • John Stafford, MD, PhD 1<br />

1Diabetes, Vanderbilt University Medical Center • 2 Diabetes, University of Texas Health Science<br />

Center<br />

Faculty<br />

The triglyceride (TG)-lowering effects of exercise have been well documented. In contrast,<br />

mechanisms for the cardiovascular protective effects of exercise are not well established. We<br />

previously showed that short-term exercise training improves insulin sensitivity but does not<br />

inhibit inflammatory pathways in immune cells from insulin-resistant subject. The purpose of this<br />

study is to evaluate metabolic changes of lipoproteins after short-term exercise training in lean,<br />

obese and type 2 diabetic (T2D) subjects. Lean, obese nondiabetic, and obese T2D individuals (n=6<br />

per group) underwent a high intensity aerobic exercise program for 15 days. Blood lipid<br />

parameters and HDL functions were analyzed before and after exercise. Blood cholesterol levels<br />

were higher in obese and T2D than in lean subjects. Exercise training primarily reduced LDL- and<br />

HDL-cholesterol (17%-21%, P


101<br />

Identification of a novel lipoprotein microRNA carrier in plasma<br />

Wanying Zhu 1 • Danielle L. Michell 1 • Ryan M. Allen 1 • Kasey C. Vickers 1<br />

Vanderbilt University Medical<br />

Staff<br />

Recently, multiple groups have detected of microRNAs (miRNA) in plasma by high-throughput<br />

sequencing. Circulating sRNAs are likely protected from RNases in plasma through their association<br />

with lipid carriers. Our lab previously reported that lipoproteins (HDL and LDL) transport miRNAs<br />

in plasma within potential intercellular communication networks. Based on these previous studies,<br />

we sought to define the distribution of miRNAs across lipid carriers in plasma.<br />

Methods: To specifically precipitate carriers, whole plasma and pre-purified HDL (density-gradient<br />

ultracentrifugation) treated with lipid removal agents (LRA and Cleanascite) for the separation of<br />

lipid-associated miRNAs. Plasma samples from humans and mice were fractionated using sizeexclusion<br />

chromatography (FPLC, Superdex 200 Increase in triplicate). Each fraction was assessed<br />

for total cholesterol, triglycerides, protein, phospholipids, and markers for lipoproteins and<br />

extracellular vesicles by western blotting. Carrier sizes in each fraction were quantified using<br />

dynamic light scattering. Total RNA was isolated from whole fractions and separated contents, lipid<br />

pellets and supernatants, after centrifugation. Real-time PCR and high-throughput sequencing were<br />

used to quantify miRNAs.<br />

Results: Results demonstrated that Cleanascite efficiently removed lipids from plasma without<br />

damaging lipoproteins, as determined by the lack of phospholipids and apolipoproteins in the<br />

supernatants. Candidate miRNAs (miR-24-3p, miR-26a-5p, miR-146a-5p, miR-92a-3p, and miR-<br />

223-3p) were detected in fractions corresponding to HDL and LDL based on the distribution of<br />

cholesterol and triglycerides. Strikingly, candidate miRNAs also entirely separated with lipids in<br />

fractions that contained low cholesterol and high phospholipid content with a mass corresponding<br />

to very small HDL. These fractions were found to contain apoA-I and spherical particles


102<br />

The Ral-Exocyst Pathway Regulates Platelet Secretion<br />

Jinchao Zhang 1 and Sidney W. Whiteheart 1<br />

1<br />

Department of Molecular and Cellular Biochemistry, College of Medicine, University of<br />

Kentucky<br />

Postdoc<br />

In Platelets, Exocyst complex has been identified as an octamer consisting of Sec3, Sec5, Sec6,<br />

Sec8, Sec10, Sec 15, Exo70 and Exo84 in platelets. The complex plays an essential role in<br />

tethering vesicles to the plasma membrane and regulating dense core granule secretion in<br />

platelets. RalA/B (family members of GTPases) are regarded as the upstream regulator of the<br />

Exocyst complex, and RalA/B binds to Sec5 and Exo84 in a GTP-dependent manner.<br />

RalA/B, sharing over 88% identity in sequences, directly interact with Exo84 and Sec5 in the<br />

Exocyst complex. The role of RalA/B are interchangeable, but RalA has the higher ability to bind<br />

to the Exocyst components in GTP binding manner in cells. Several groups suggest that<br />

interrupting the association Sec3 and Exo70 with plasma membrane could disrupt exocytosis in<br />

other cells. However, it is little known how the role of the Exocyst complex in platelet secretion.<br />

Here we ask the question whether inhibitors of RalA/B could affect granule secretion or not in<br />

platelets. And what is the exact role of the Exocyst complex in granule secretion? How is the<br />

Exocyst complex regulating vesicles tethering in secretion process? Firstly, specific RalA/B<br />

inhibitors, RBC8 and BQU57, were used to investigate the role of RalA/B in granule secretions.<br />

From the biochemical perspective, these inhibitors affect RalA/B bound to their downstream<br />

effector (RLP76) due to the Ral-GDP bound forms. We also found the inhibitors of RalA/B<br />

affects platelet spreading (data are not shown here). At the same time, we also answer the<br />

questions of the localization of Rals and Exo70 (one of the Exocyst component) as well as their<br />

association with F-actin.<br />

118


103<br />

Alternating heights of the R wave in ECG: possible link with depolarization<br />

alternans<br />

Sahar Varnoosfaderani 1 , David Wasemiller 1 , Siqi Wang 1 , Paul Anaya 2 , and Abhijit<br />

Patwardhan 1 .<br />

1<br />

Department of Biomedical Engineering and 2 Division of <strong>Cardiovascular</strong> Medicine. University of<br />

Kentucky.<br />

Alternans of the T wave in the ECG (TWA) is widely investigated as a potential predictor of<br />

ventricular arrhythmia, however, clinical trials show that TWA has high negative predictive<br />

value but poor positive predictive value. A possible reason that TWA has a large number of false<br />

positives is that a pattern of alternans, concordant alternans, may not be as arrhythmogenic as<br />

discordant alternans. Currently, it is not possible to discern the pattern of alternans using<br />

clinical ECGs. However, our research using tissue and cellular level electrophysiological<br />

measurements suggest that depolarization alternans which affects the pattern of alternans may<br />

manifest itself in the amplitude of the R wave of the ECGs. In order to investigate the link<br />

between depolarization alternans and changes in ECGs, we used a mathematical model which<br />

simulated ECGs from the cellular level changes observed in our experimental studies. These<br />

results suggest that the changes in ECGs should appear as alternating pattern of the heights of<br />

the R wave. However, there are a variety of factors which may also cause the R wave heights to<br />

change. We use signal analysis and statistical modeling to determine the link between the<br />

observed changes in R wave heights and depolarization alternans. Results from ECGs recorded<br />

from patients show that heights of the R wave can change as predicted by our experimental<br />

results and mathematical models. These results support further exploration of the link between<br />

depolarization and repolarization alternans as it has the potential to improve the positive<br />

predictive value of TWA.<br />

Supported by grants from the Kentucky Science and Engineering Foundation (KSEF RDE18)<br />

and NSF EPSCoR RII Track-2.<br />

119


NOTES<br />

120


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