Lack of NLRP3-Inflammasome Leads to Gut-Liver AXIS Derangement and Increases Hepatic Injury in a Mouse Model of Non-Alcoholic Fatty Liver Disease

POSTER PRESENTATIONS patients namely, the NAFLD activity score, fibrosis, obesity and angiogenesis score (CD34-positive cells). Results: About 13 genes including VEGFR1, PIK3CA, CXCL8, NOS3, EREG, CCL2, PRKCE, PPAR-gamma, PROK2, RUNX1, SIRT1, HMOX1 and CXCR4 showed significantly different gene expression in the RT-PCR analysis in patients with NASH as compared to healthy controls. In the clinical analysis, a few genes, namely, PPAR-gamma, SIRT1, CXCR4, CCL2 and RUNX1 showed substantial correlations with both fibrosis scores and NAFLD activity score of the patients. Interestingly, the aforementioned genes, except for RUNX1, also showed good correlations with angiogenesis scores in the liver tissues, suggesting the plausible role of these genes linking lipid metabolism with hepatic angiogenesis in NAFLD. The expression of CXCL8 and VEGFR1 exhibited significant association with obesity score of the patients, indicating an important role of these angiogenic genes in the regulation of obesity in NAFLD patients. Conclusions: The current study identifies the gene players that are associated with both lipid metabolism and angiogenesis and also play an important role in the pathogenesis of NAFLD. Several in vitro studies are now underway to explore the interactions and mechanistic links between these genes in NAFLD. SAT-314 GALECTIN-3 DEFICIENCY EXACERBATES LIVER STEATOSIS BUT PROTECTS FROM STEATOHEPATITIS AND IL-33/IL-13 DEPENDENT FIBROSIS IN HFD-INDUCED OBESITY MOUSE MODEL I. Jeftic1, N. Jovicic1, J. Pantic1, N. Arsenijevic1, M.L. Lukic1, N. Pejnovic1. 1 Center for Molecular Medicine and Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Republic of Serbia E-mail: [email protected] Background and Aims: Galectin-3, a β-galactoside-binding lectin participates in the pathogenesis of metabolic disorders, but its importance in obesity-associated liver pathology is incompletely defined. In this study, we aimed to dissect the role of Gal-3 in liver inflammatory response and fibrosis, key parameters in the pathogenesis and progression of non-alcoholic steatohepatitis (NASH), induced by obesogenic high-fat diet (HFD). Methods: Gal-3-deficient (LGALS3−/−) and wild-type (WT) C57Bl/6 male mice were placed on obesogenic high-fat diet (HFD, 60% kcal fat) for 12 and 24 weeks, in some experiments, after 10 weeks on HFD WT and LGALS3−/− mice were injected intraperitoneally five times every other day at 0.5 μg per injection with murine recombinant IL-33 and metabolic, gene expression, histological and immunophenotypical analyses in liver and peripheral blood were performed. Results: In comparison to WT mice, HFD-fed LGALS3−/− mice developed increased obesity, more pronounced liver steatosis which was accompanied by upregulation of hepatic FAS, Abca-1, PPAR-γ and Cd36 expression. However, hepatocellular damage, inflammation and fibrosis were more extensive in WT mice which was associated with increased myeloid DCs and proinflammatory monocytes/ macrophages infiltrated into the livers, and higher hepatic CCL2, NLRP3 inflammasome, IL-1β and NADPH-oxidase components mRNA expression. HFD-fed WT mice had higher number of hepatocytes that strongly expressed IL-33 and hepatic CD11b+IL-13+ cells, increased levels of IL-33 and IL-13 and upregulated IL-33, ST2 and IL-13 mRNA in liver compared to LGALS3−/− mice. Additionaly, IL-33 failed to induce ST2 upregulation and IL-13 production by LGALS3−/− peritoneal CD11b+ macrophages in vitro. In vivo administration of IL-33 enhanced liver fibrosis in HFD-fed mice in both genotypes, albeit to a significantly lower extent in LGALS3−/− mice which was associated with less numerous hepatic IL-13 expressing myeloid cells. Conclusions: Gal-3 attenuates steatosis, but promotes liver injury, inflammation and fibrosis, thus participates in the progression of NASH induced by obesogenic diet in mice. Further, we show for the first time that Gal-3 plays an important regulatory role in the newly described profibrotic IL-33/ST2/IL-13 pathway.

SAT-315 LACK OF NLRP3-INFLAMMASOME LEADS TO GUT-LIVER AXIS DERANGEMENT AND INCREASES HEPATIC INJURY IN A MOUSE MODEL OF NON-ALCOHOLIC FATTY LIVER DISEASE I. Pierantonelli1, L. Agostinelli1, C. Rychlicki1, M. Gaggini2, C. Fraumene3, E. Mingarelli1, C. Saponaro 2, V. Manghina4, E. Buzzigoli 2 , C. Pinto1, L. Trozzi1, S. Saccomanno1, A. Benedetti1, M. Marzioni1, S. De Minicis1, S. Uzzau 3,4, A. Gastaldelli 2, G. Svegliati-Baroni1,5. 1 Polytechnic University of Marche, Ancona; 2Cardiometabolic Risk Lab, Institute of Clinical Physiology, CNR, Pisa; 3Porto Conte Ricerche, Parco Scientifico e Tecnologico della Sardegna, Alghero; 4Department of Biomedical Sciences, University of Sassari, Sassari; 5Obesity Center, Polytechnic University of Marche, Ancona, Italy E-mail: [email protected] Background and Aims: Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common form of chronic liver disease. The NLRP3inflammasome can elicit a pro-inflammatory response when activated but also regulates intestinal homeostasis and gut microbiota composition. The NLRP3-inflammasome has been implicated in the pathogenesis of obesity, diabetes and in the progression of chronic liver injury, but its role in NAFLD is controversial. Therefore, the aim of this study was to investigate the role of NLRP3-inflammasome in NAFLD. Methods: Nlrp3 −/− and wild-type (WT) C57BL/6 mice were fed with a high-fat diet with fructose in drinking water (HFHC), or a chow diet, for 12 weeks. Results: Nlrp3 −/− HFHC showed reduced energy expenditure and this lead to increased body weight, higher fat mass and adipose tissue TNF-α expression. Nlrp3 −/− HFHC developed more hepatic steatosis, measured by triglyceride content, compared to WT HFHC because of augmented SCD-1 activity (a regulator of hepatic lipogenesis) and PPARγ2 expression (that regulates lipid uptake and storage). Increased mitochondrial fatty acid oxidation and reduced expression of NRF2, the “master regulator” of antioxidant response, led to increased superoxide production in Nlrp3 −/− HFHC. After HFHC, lack of NLRP3-inflammasome was associated with significantly alteration in intestinal microbiota (higher Firmicutes/Bacteroidetes ratio, and increased levels of mucus-degrading bacteria Akkermansia and Desulfovibrio) which was associated to a “leaky” intestinal barrier. Concomitantly, hepatic TLR4 and TLR9 expression, inflammatory macrophages in the liver, and NAS score were increased in Nlrp3 −/− HFHC mice, indicating increased inflammatory response and liver injury. Gut decontamination by antibiotics reduced body weight, bacterial translocation and liver injury in Nlrp3 −/− HFHC mice. Conclusions: Lack of NLRP3-inflammasome is linked to severe metabolic alterations and development of NASH possibly due to translocation of bacterial products. SAT-316 A NUCLEAR MESSENGER LINKS CANNABINOID-1 (CB1) SIGNALLING TO FATTY LIVER S. Azar1, A. Drori1, I. Knani1, S. Udi1, R. Hadar1, K.V. Vemuri2, A. Makriyannis2, J.M. Peters3, J. Tam1. 1The Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel; 2Center for Drug Discovery, Northeastern University, Boston; 3Department of Veterinary and Biomedical Sciences, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, United States E-mail: [email protected] Background and Aims: The endocannabinoid (eCB) system is increasingly recognized as being of crucial importance in obesityrelated metabolic abnormalities, one of which is hepatic steatosis. eCBs, via the activation of CB1 receptors in the liver, modulate hepatic lipogenesis and fatty acid oxidation. CB1 receptor blockade reverses the high-fat diet (HFD)-induced hepatic steatosis, and increases the

Journal of Hepatology 2016 vol. 64 | S631–S832

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