Taken together, our data indicate that rapid progression of liver injury in the HFCD-fed JAM-A-/- mice can be attributed to increased intestinal permeability resulting in enhanced translocation of bacterial products that drive hepatic inflammation primarily via activation of the innate immune system. CONCLUSION: These findings implicate intestinal epithelial permeability as a major factor in NASH severity. Therapies being studied in the lab to restore gut integrity in HFCD-fed JAM-A-/-

mice may prove to be of clinical value. Further, our data suggest that the HFCD JAM-A-/- model may be a powerful new tool to study the role of host defenses in NASH pathogenesis. Disclosures: The following people BGB324 nmr have nothing to disclose: Khalidur Rahman, Natalie Thorn, Pradeep Kumar, Asma Nusrat, Charles A. Parkos, Frank A. Anania C/EBP homologous protein (CHOP) is normally undetectable and induced under conditions of endoplasmic reticulum (ER) stress. The saturated toxic free fatty acid, palmitate, induces ER stress including CHOP expression and apoptosis, termed lipoapoptosis. However, the pathways of palmitate-induced CHOP-dependent lipoapoptosis are obscure. Recent studies have shown that microRNAs can promote apoptosis under conditions of ER stress. Therefore, we hypothesized that pal-mitate-regulated

microRNAs derepress CHOP expression, thus promoting lipoapoptosis. Our aim was to identify and functionally characterize PD0325901 cost microRNAs repressed by palmitate, which in turn might regulate CHOP expression. Methods: RNA sequencing was performed on microRNAs enriched from hepatocyte cell lines treated with palmitate. Tunicamycin treated cell lines were included as a control. Computational tools were used to identify regulatory 上海皓元 microRNAs of interest. Taqman assays were used to confirm the expression of candidate microRNAs. Gain-of-function, loss-of-function and a reporter gene assay were used to confirm the microRNA binding and regulatory functions. Results: Treatment of hepatocytes with palmitate or tunicamycin results in a significant reduction in miR-615-3p levels before the onset of significant

apoptosis. There is a single miR-615-3p binding site in the 3′ untranslated region of the Chop mRNA. Luciferase reporter gene assay showed that exogenously transfected miR-615-3p binds to and represses the activity of the reporter gene. Using a precursor of miR-615-3p to augment the levels of this microRNA, there is a reduction of CHOP protein levels under palmitate and tunica-mycin treatment conditions. Finally, a significant reduction in palmitate- and tunicamycin-induced apoptosis was observed in cells transfected with a precursor of miR-615-3p. Conclusions: Our working model is that palmitate lowers miR-615-3p levels, thus derepressing CHOP expression under conditions of ER stress, consequently promoting lipoapoptosis.