Conclusions: Silencing NGF may have a beneficial, anti-inflammatory and protective effect in acute hepatotoxicity models. The following people have nothing to disclose: Rafael Bruck, Einav Hubel, Isabel Zvibel Aim: The goal

of this study was to investigate the relationship between inflammation-related microRNAs and NAFLD patho-genesis in a rodent model with metabolic syndrome. Methods: Leptin receptor deficient (Leprdb/db) mice were fed a high fat diet or standard chow for 5 or 10 weeks. Liver histology was scored for steatosis, ballooning, inflammation, fibrosis and NAFLD activity score (NAS) by a hepatopathologist; and classified Forskolin nmr into DM (diabetes mellitus), NAFL (nonalcoholic fatty liver) and NASH (nonalcoholic steatohepatitis) groups. Serum were analyzed for metabolic changes, and hepatic microRNA (miR-122, −146a, −155, and −223) levels were determined. Results: Greater CB-839 order than half of the mice fed high-fat diet developed NASH compared to controls. Mice with NAFL and NASH had elevated hepatic triglycerides,

serum aminotransferases, inflammatory cytokines (IL-6 and TNF-α), glucose and insulin levels. Expression of miR-155 and −223 (p<0.01 for both] were increased in NAFL and NASH mice, while miR-122 was decreased, relative to DM. Expression of miR-146a were also increased in the livers of NAFL and NASH mice compared to DM mice (p<0.03), though the extent of increase was smaller compared to miR155 and 223. Increased levels of miR155 correlated with upregulation of its transactivator and target, NF-KB, in NASH livers, indicated by increased phosphoryla-tion of the p65 subunit of NF-KB, and increased expression of MCP-1, an NF-KB regulated chemokine and CCR2, its cognate receptor. DNA ligase Consistent with the upregulation of miR-155 (and down-regulation of miR-122), we observed increased infiltration of macrophages in NASH livers indicated by increased F480 and Mac-2 staining; and elevated CD68, F480 and CD11b gene expression levels in the NASH livers, relative to DM. Also consistently,

T cell markers such as CD3gamma, IFN-gamma, MHCII and CD8 were upregulated in NASH livers. Regression analysis revealed that correlating miR-155 versus miR-223 gave a Pearson r of 0.91. These miRs were strongly associated with %mass increase (r=0.61, p<0.0001 for both), ALT & AST (r>0.56, p<0.001 for all), adiponectin (r<-0.50 for both, p<0.001), and NAS (Spearman r=0.50, p<0.001 for both). Conclusions: MicroRNAs associated with inflammation, especially miR155 and its known targets, were significantly altered in this mouse model of NASH, suggesting their involvement in cytokine/chemokine induction and immune cell recruitment and activation. The significant Pearson’s correlation between MiR-155 and miR-223 indicated that these microRNAs are involved in similar inflammatory cascades in NASH progression. These studies emphasize a key role for these microRNAs in NASH pathogenesis. Kris V.