Adipose type I interferon signalling protects against metabolic dysfunction

POSTER PRESENTATIONS Methods: Tamoxifen-inducible global NLRP3 KI (Nlrp3A350V/+CreT) and wild type (WT) mice (8–12 weeks of age) were administered control chow diet or diet containing the ASK1 inhibitor GS-444217 (0.2% in chow) starting 2 days before tamoxifen injection and continued for 6 weeks. Liver inflammation was evaluated histologically and by gene expression analyses using RT-PCR. Liver fibrosis was assessed by hydroxyproline levels and gene expression analyses using RT-PCR for markers of fibrosis and hepatic stellate cell activation. The pharmacodynamic activity of ASK1 inhibition was evaluated by measuring liver levels of phosphorylated p38 by western blot. Additional endpoints included evaluation of liver levels of cleaved caspase 3 by western blot and serum ALT levels. Results: Untreated NLRP3 KI mice developed liver inflammation and fibrosis as demonstrated by neutrophil cell infiltration, increased hepatic expression of pro-inflammatory genes TNF-alpha and Ly6c, increased hepatic hydroxyproline levels, and increased hepatic expression of pro-fibrotic genes pro-col1-alpha, alpha-SMA and TIMP1. Treatment with an ASK1 inhibitor reduced liver fibrosis as demonstrated by a 33.5% reduction in hydroxyproline levels ( p < 0.01) and reduced RNA levels of pro-col1-alpha (8.2 vs. 2.9-fold, p < 0.01), alpha-SMA (4.5 vs. 2.1-fold, p < 0.01) and TIMP1 (48.8 vs. 27.8fold, p < 0.01). ASK1 inhibition also significantly reduced p38 phosphorylation and caspase 3 cleavage in the liver and reduced serum ALT levels (144.0 vs. 78.8 U/L, p < 0.05). Conclusions: In mice with constitutive activation of the NLRP3 inflammasome, ASK1 inhibition reduced liver fibrosis and apoptosis and reduced serum ALT levels. These data provide insight into the hepatoprotective mechanisms of ASK1 inhibition and support the development of selonsertib for the treatment of NASH. SAT-357 Inhibition of IL6 trans-signaling leads to gut microbiotadependant mature-onset obesity and metabolic syndrome T. Lanton1, O. Levkovitch1, S. Perless2, Y. Tam3, J. Rachmilewitz1, R. Abramovitch4, S. Rose-John5, E. Galun1, J.H. Axelrod1. 1The Goldyne Savad Institute of Gene Therapy, Hadassah Hebrew University Hospital; 2 Raziel Therapeutics Ltd.; 3School of Pharmacy, Faculty of Medicine, Hebrew University; 4Magnetic Resonance Imaging/Magnetic Resonance Spectroscopy Laboratory, Hadassah Hebrew University Hospital, Jerusalem, Israel; 5Institut für Biochemie, Christian-AlbrechtsUniversität zu Kiel, Kiel, Germany E-mail: [email protected] Background and Aims: Altered metabolic states such as exercise and HFD-induced obesity are associated with persistent increased IL6 production; however the causal role of IL6 and IL6 trans-signaling in particular in the spontaneous development of age-related obesity and fatty liver disease remains controversial. IL6 trans-signaling relies upon the release of the soluble IL6R (sIL6R), which binds IL6 to form an agonistic IL6/sIL6R complex. Here we examine the hypothesis that IL6 trans-signaling plays a crucial role in the control of weight gain and glucose homeostasis. Methods: Wild type mice and transgenic (C57BL/6) littermates expressing high levels of the IL6/sIL6R antagonist, sgp130Fc, were compared at ages ranging from 2 to 14 months for food intake, weight gain, metabolic disease, and hepatosteatosis. Results: After the age of 5 months, there was a dramatic rise in body weight in sgp130Fc animals compared to littermate controls which was preceded by hyperphagia and which correlated with reduced energy expenditure. Sgp130Fc mice also displayed increased fat storage in the liver while reducing free fatty acid levels in the blood but but without notable alteration in the expression of hepatic triglyceride synthesis genes. Inhibition of trans-signaling also lead to impaired glucose tolerance due to peripheral insulin resistance in aged (12 months) mice, but without altered hepatic gluconeogenesis or defects in pancreatic insulin nor glucagon secretion. Notably, obesity and hepatosteatosis in the sgp130Fc mice was accompanied by significant changes in the intestinal microbiota, even though an

increased inflammatory signature in the liver was not evident (TNF, IL-6, IL-10, and TLR4). Nonetheless, prolonged antibiotic treatment in the sgp130Fc mice halted weight-gain and induced euglycemia. Conclusions: These findings indicate that IL-6 trans-signaling protects mice from mature-onset obesity, hyperglycemia, and hepatosteatosis in a mechanism involving alterations of the gut microbiota. SAT-358 Adipose type I interferon signalling protects against metabolic dysfunction T. Adolph1, V. Wieser1, C. Grander1, F. Grabherr1, B. Enrich1, P. Moser2, A. Moschen1, S. Kaser1, H. Tilg1. 1Department of Internal Medicine I; 2 Medical university Innsbruck, Innsbruck, Austria E-mail: [email protected] Background and Aims: Chronic inflammation emerges as a potent driver of metabolic dysregulation in obesity and associated nonalcoholic fatty liver disease (NAFLD). Type I interferon signaling initiated by innate and adaptive immunity modulates inflammatory responses. However, the impact of type I interferon signaling on metabolic dysregulation and NAFLD is unknown. Methods: We generated tissue-specific knockout mice that allowed deletion of interferon (alpha and beta) receptor 1 (Ifnar1) in hepatocytes (Ifnar1 Δhep), adipocytes (Ifnar1 Δat), intestinal-epithelial cells (Ifnar1 ΔIEC) or myelocytes (Ifnar1 Δmyel ). We exposed these mice to a high-fat diet or a methionine-choline deficient (MCD) diet and assessed metabolic dysregulation and hepatic disease. Additionally, we investigated the impact of weight loss induced by laparoscopic adjustable gastric banding (LAGB) in obese patients on the expression of type I interferon regulated genes. Results: Type I interferon responses are elicited by long chain fatty acids in murine hepatocytes and macrophages. Similarly, a high-fat diet induced type I interferon-regulated gene expression in the liver of wild-type mice. Hepatocyte-specific deletion of Ifnar1 worsened steatosis and inflammation induced by a MCD diet. In contrast, adipose-tissue-specific deletion of Ifnar1 worsened metabolic dysregulation induced by a high-fat diet. Abrogated Type I interferon signalling in myeloid or intestinal-epithelial cells did not modulate susceptibility to metabolic or hepatic disease. LAGB-induced metabolic control in obese patients was associated with increased expression of interferon-regulated genes in subcutaneous adipose tissue and liver. Conclusions: Our study implicates type I interferon signalling in metabolic dysregulation and NAFLD. Further studies are warranted that investigate the mode of action of type I interferon signalling in metabolic diseases. SAT-359 CD103+ DCs are a key population in the progression of nonalcoholic steatohepatitis: could DCs represent a novel therapeutic application in NASH? E.-C. Heier1, A. Meier1, T. Tschernig2, F. Lammert1, V. Lukacs-Kornek1. 1 Internal Medicine II; 2Insitute of Anatomy and Cell Biology, University of Saarland, Homburg, Germany E-mail: [email protected] Background and Aims: Non-alcoholic fatty liver (NAFL) is the hepatic consequence of metabolic syndrome and can progress to nonalcoholic steatohepatitis (NASH). Dendritic cells (DCs) represent a heterogeneous cell population among which CD103+ DCs play a significant role in immunity and tolerance. We aimed to analyze their role in disease progression and their potential therapeutic application in NASH. Methods: Wild type (WT) and animals lacking CD103+ DCs (KO) were subjected to methionine choline deficient (MCD) and high sucrose (HSD) diet. Steatosis progression towards steatohepatitis was analyzed using multicolor FACS analyses, cytokine and qPCR array. In order to investigate the therapeutic effect of DCs, bone marrow

Journal of Hepatology 2017 vol. 66 | S543–S750

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