studies

664A AASLD ABSTRACTS HEPATOLOGY, October, 2015
than total cholesterol, we specifically show that oxLDL significantly
contributes to lysosomal dysfunction, cholesterol homeostasis
and the hepatic inflammatory response.
Disclosures:
The following authors have nothing to disclose: Sofie Walenbergh, Tom Houben,
Tim Hendrikx, Patrick van Gorp, Mike Jeurissen, Marie-Hélène Lenders, Marion J.
Gijbels, Jogchum Plat, Marten H. Hofker, Christoph J. Binder, Dieter Luetjohann,
Fons Verheyen, Ger H. Koek, Ronit Shiri-Sverdlov
923
Cholesterol crystallization within hepatocyte lipid droplets
and its role in NASH
George N. Ioannou 2,1 , Savitha Subramanian 1 , Alan Chait 1 , Matthew
M. Yeh 1 , W. G. Haigh 2 , Christopher Savard 2,1 ; 1 University
of Washington, Seattle, WA; 2 Veterans Affairs Puget Sound
Healthcare System, Seattle, WA
Background/Aims We recently reported that cholesterol crystals
were present within the lipid droplets of hepatocytes in
patients and mouse models with NASH. We sought to further
characterize the process of cholesterol crystallization in hepatocyte
lipid droplets and its role in the development of Kupffer
cell (KC) crown-like structures (CLS). Methods C57BL/6J, wildtype
mice were assigned to a high-fat (15%, w/w) diet for
6 months supplemented with 0%, 0.25%, 0.5%, 0.75%, or
1% dietary cholesterol (5 groups, n=12 mice/group). HepG2
hepatoma cells were exposed to varying concentrations of LDL
cholesterol, oleic acid, and ACAT inhibitor, in order to induce
lipid droplet formation and cholesterol crystallization. Results
Fibrosing steatohepatitis developed at a dietary cholesterol
concentration ≥0.5%, whereas mice on a diet of 0% or 0.25%
cholesterol developed only simple steatosis. Hepatic cholesterol
crystals and CLSs were also only observed at a dietary cholesterol
concentration ≥0.5%. CLSs consisted of activated KCs that
surrounded and processed cholesterol-crystal containing remnant
lipid droplets of dead hepatocytes and stained intensely
positive for NLRP3 and activated caspase1. When HepG2
cells were exposed to 2000 mg/ml LDL and 200 mM Oleic
acid for >20 days, a sub-population of cells displayed birefringent
cholesterol crystals around the periphery of large lipid
droplets. Conclusion A specific threshold dietary cholesterol
concentration that leads to cholesterol crystallization within
hepatocyte lipid droplets also leads to CLSs and fibrosing
NASH, suggesting a causative association. Exposure of KCs in
CLSs to cholesterol crystals activates the NLRP3 inflammasome.
We developed an in vitro cell culture model of steatosis and
cholesterol crystallization in HepG2 cells.
Disclosures:
The following authors have nothing to disclose: George N. Ioannou, Savitha
Subramanian, Alan Chait, Matthew M. Yeh, W. G. Haigh, Christopher Savard
924
Fenofibrate and LXRα agonist combination attenuated
intrahepatic inflammation in non-alcoholic fatty liver.
Eun Chul Jang 1 , Dae Won Jun 2 , Seung Min Lee 3 , Yong Kyun
Cho 4 , Sang Bong Ahn 5 ; 1 Department of Occupational and Environmental
Medicine, Soonchunhyang University Cheonan Hospital,
Cheonan, Korea (the Republic of); 2 Department of Internal
Medicine, Hanyang University College of Medicine, Seoul, Korea
(the Republic of); 3 Department of Food and Nutrition, Sungshin
Women’s University, Seoul, Korea (the Republic of); 4 Department
of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan
University, School of Medicine, Seoul, Korea (the Republic of);
5 Department of Internal Medicine, Eulji University School of Medicine,
Seoul, Korea (the Republic of)
Background/Aims: Liver X receptors (LXR) is key transcription
factor in the regulation of lipid and cholesterol metabolism.
in addition, LXRα has been implicated as regulator of inflammation.
LXRα activation is associated with hepatic steatosis
and hyperlipidemia in mice. Fenofibrate, a PPARα agonist and
omega-3, an antihypertriglyceride agent, lead to a reduction
of hyperlipidemia. The aim of this study to investigate whether
concurrent effect of LXRα and fenofibrate or omega-3 can produce
synergic benefits in high-fat diet induced obese mice.
Methods: Normal chow and high-fat diet mice treated with
LXRα agonist (T0901317), or combined fenofibrate or omega-3
for 4 weeks. Hematoxylin and eosin staining was performed
on liver tissue extracts after animal sacrifice. SREBP1c, FAS,
SCD-1, PPAR-α, and MCP-1 mRNA expressions were assessed
with reverse transcription-polymerase chain reaction. Results:
LXRα agonist increase intrahepatic fat amount in normal chow
group. Degree of intrahepatic inflammation was not different
among LXRα agonist, or combined with fenofibrate/omega-
3. In NAFLD model, the combined treatment with fenofibrate
did not increase hepatic steatosis. LXRα agonist and/or fenofibrate
or omega-3 decreased intrahepatic inflammation. In
high-fat diet groups, combined treatment with fenofibrate markedly
reduced the expression of genes involved in lipogenesis,
including srebp-1c, fas and scd1. Furthermore, LXRα agonist
and/or fenofibrate or omega3 treatment decreased expression
of abca-1, abcg5, and abcg8 genes, three vital genes for
cholesterol efflux in diet induced fatty liver model, but those
expressions were opposite in normal chow group. Intraheptic
MCP-1, and TNF-α expression and markers of inflammasome
were also decreased in NAFLD group. Conclusion: LXRα agonist
and fenofibrate combination treatment attenuated hepatic
inflammation in NAFLD model.
Disclosures:
The following authors have nothing to disclose: Eun Chul Jang, Dae Won Jun,
Seung Min Lee, Yong Kyun Cho, Sang Bong Ahn