studies

HEPATOLOGY, VOLUME 62, NUMBER 1 (SUPPL) AASLD ABSTRACTS 647A
rates by regulating endocrine hormone levels such as thyroid
hormone levels. Fasting is an adaptive mechanism developed
in mammals for nutrient depravation. Fasting is characterized
with increase in free fatty acid levels in serum and liver causing
hepatic steatosis along with several other physiological
changes. These physiological changes in fatty acid metabolism
during fasting are similar to diabetes condition. In this study
we aim to identify role of Tgr5 in fatty acid metabolism using
fasting model. Methods: Male C57BL/6J (WT) and Tgr5 knock
out (Tgr5-/-) mice in pure C57BL/6J background were either
fed ad libitum or fasted for 24 hrs. Lipid profiles of serum, liver
and adipose tissues were analyzed. Quantitative real-time PCR
was used to assay mRNA expression levels of the genes in bile
acid, cholesterol and lipid metabolism. A Tgr5 specific agonist
INT-777 (Intercept Pharma) was used to activate Tgr5 signaling
in mice. Results: Fasting increased hepatic lipid accumulation
in both WT and Tgr5-/- mice. Lack of Tgr5 attenuated fasting-induced
hepatic triglyceride and fatty acids accumulation compared
to WT mice, without changes in adipose tissue lipolysis.
Gene expression analysis showed Tgr5-/- mice have increased
expression of hepatic lipolysis genes such as Cpt1, Pgc-1α
and autophagy gene LC3II levels. Comprehensive laboratory
animal monitoring system (CLAMS) metabolic studies showed
Tgr5-/- mice have increased physical activity and energy
expenditure. Tgr5-/- mice also showed decrease in expression
of hepatic fatty acid transporter Cd36 and decreased hepatic
fatty acid uptake. Additionally, Tgr5-/- mice had increased
hepatic Stat5 activation, which is known to regulate hepatic
lipid metabolism. Moreover, a Tgr5 agonist INT-777 treatment
increased hepatic Cd36 expression and decreased hepatic
Lc3II levels in fasted mice. Conclusion: Although Tgr5 is not
expressed in hepatocytes, Tgr5 may play a role in regulation
of hepatic fatty acid metabolism during fasting. Lack of
Tgr5 attenuates fasting-induced hepatic steatosis by decreasing
hepatic fatty acid uptake and increasing hepatic lipolysis.
Disclosures:
The following authors have nothing to disclose: Ajay C. Donepudi, Shannon M.
Boehme, John Chiang
886
Hepatic NOD-like receptors, pyrin domain-containing
3 (NLRP3) inflammasome activation is associated with
histological severity in patients with nonalcoholic fatty
liver disease
Hironori Mitsuyoshi, Kohichiroh Yasui, Tasuku Hara, Hiroyoshi
Taketani, Hiroshi Ishiba, Akira Okajima, Yuya Seko, Atsushi
Umemura, Taichiro Nishikawa, Kanji Yamaguchi, Michihisa Moriguchi,
Yoshio Sumida, Masahito Minami, Yoshito Itoh; Kyoto Prefectural
University of Medicine, Kyoto, Japan
Background and Aims: Nonalcoholic fatty liver disease
(NAFLD) is the hepatic manifestation of metabolic syndrome,
which is associated with dysregulated inflammasome activation
caused by obesity. Inflammasomes are intracellular multiprotein
complexes, comprising nucleotide-oligomerization and binding
domain (NOD)-like receptors, the apoptosis-associated specklike
protein containing a CARD (ASC), and procaspase-1.
Assembly of these components in response to metabolic stress
results in caspase-1 activation, leading to interleukin-1 beta
(IL-1β) and IL-18 activation, which exacerbates inflammation
in systemic organs, including the liver. Here, we examined the
role of inflammasomes in the development of NAFLD. Methods:
Biopsy-proven patients with NAFLD (n = 91) were enrolled.
Liver histology was assessed according to the NAFLD activity
score (NAS). Hepatic (n = 91) and blood (n = 37) levels of the
NOD-like receptor family, pyrin domain-containing 3 (NLRP3),
ASC, procaspase-1, IL-1β, and IL-18 were quantified by realtime
polymerase chain reaction (PCR). Adiponutrin polymorphisms
(rs738409, C>G) were determined by TaqMan PCR.
Serum IL-1β and IL-18 levels were measured by ELISA and
liver tissue caspase-1 expression was evaluated by immunostaining.
Results: Hepatic mRNA levels of NLRP3, ASC, procaspase-1,
IL-1β, and IL-18 were significantly higher in patients
with NAFLD compared with control livers. Blood procaspase-1
mRNA levels were significantly higher in NAFLD patients compared
with healthy controls. In contrast to the blood mRNA
levels, hepatic mRNA levels of NLRP3 inflammasome components
were significantly associated with adiponutrin G alleles.
Hepatic procaspase-1 and IL-1β mRNA levels correlated significantly
with lobular inflammation, hepatocyte ballooning,
and total NAS. Serum IL-18 levels were significantly higher
in NAFLD patients compared with controls, while IL-1β levels
exhibited a non-significant increase. Serum IL-1β and IL-18 levels
were significantly correlated with steatosis, total NAS and
serum transaminase levels. Caspase-1-positive cells were scattered
within the portal tracts, inflammatory foci, and ballooning
hepatocytes. Immunofluorescence staining showed colocalization
of caspase-1 with the macrophage marker CD68. Conclusions:
Our results suggest that NLRP3 inflammasomes are
primed in the liver in NAFLD patients and that this process is
influenced by adiponutrin genotypes. Furthermore, our results
indicate that NLRP3 inflammasomes are activated exclusively
in Kupffer cells or infiltrating macrophages, leading to histological
NAFLD progression through IL-1β and IL-18 production.
Disclosures:
Yoshito Itoh - Grant/Research Support: MSD, Chugai Phamaceutical CO., Bristol-Myers
Squibb, Dainippon Sumitomo, Otsuka, Takeda, Fujifilm medical, Eisai,
Mitsubishi Tanabe, AstraZeneca; Speaking and Teaching: MSD
The following authors have nothing to disclose: Hironori Mitsuyoshi, Kohichiroh
Yasui, Tasuku Hara, Hiroyoshi Taketani, Hiroshi Ishiba, Akira Okajima, Yuya
Seko, Atsushi Umemura, Taichiro Nishikawa, Kanji Yamaguchi, Michihisa Moriguchi,
Yoshio Sumida, Masahito Minami
887
Liver MicroRNA-21 is Overexpressed in Non Alcoholic
Steatohepatitis in Patients and Contributes to this Disease
In Two Mouse Models by restoring PPARα expression
Xavier Loyer 1 , Valerie Paradis 3 , Carole Hénique 1 , Anne-Clémence
Vion 1 , Nathalie Colnot 3 , Coralie L. Guerin 1 , Cécile Devue 1 , Sissi
On 1 , Jérémy Scetbun 1 , Mélissa Romain 1 , Jean-Louis Paul 4 , Marc
E. Rothenberg 5 , Patrick Marcellin 2 , Francois Durand 2 , Pierre
Bedossa 3 , Carina Prip-Buus 6 , Eric Baugé 7 , Bart Staels 7 , Chantal
Boulanger 1 , Alain Tedgui 1 , Pierre-Emmanuel Rautou 1,2 ; 1 INSERM,
U970, Paris Cardiovascular Research Center - PARCC@HEGP,
Paris, France; 2 Hepatology, Hôpital Beaujon, APHP, Clichy,
France; 3 Pathology, Hôpital Beaujon, APHP, Clichy, France; 4 Service
de Biochimie, Hôpital Européen Georges Pompidou, AP-HP,
Paris, France; 5 Cincinnati Children’s Hospital Medical Center, University
of Cincinnati College of Medicine, Division of Allergy and
Immunology, Department of Pediatrics, Cincinnati, OH; 6 INSERM,
U1016, Institut Cochin, Université Paris Descartes, Sorbonne Paris
Cité, Paris, France; 7 European Genomic Institute for Diabetes
(EGID); INSERM UMR1011, University of Lille; and Institut Pasteur
de Lille, Lille, France
Objective: Previous studies suggested that microRNA-21
may be up-regulated in the liver in non alcoholic steatohepatitis
(NASH), but its role in the development of this disease
remains unknown. This study aimed to determine the role of
microRNA-21 in NASH. Design: We assessed features of
NASH in two mouse models of NASH where microRNA-21
was either pharmacologically inhibited or genetically deleted: