Though significant research has been carried out on the leptin induced NADPH oxidase in fibrogenesis, the molecular mechanisms that connect leptin-NA-DPH oxidase axis in upregulation of TGF p signaling has been unclear. Recently, there is an increased emphasis on non-coding RNAs in controlling NASH progression. For this we hypothesized that leptin mediated

upregulation of NADPH oxidase and its subsequent induction of mir21 Selleckchem Pifithrin�� via Nf-κb activation causes increased TGF p signaling by inhibiting SMAD7. A high fat (60% kCal) diet fed chronic mouse model was used for inducing fatty liver and subsequent steatohepatitic lesions following administration of hepatotoxin bromodichloromethane. To prove the role of Leptin-NADPH oxidase-miR21 axis, mouse deficient in genes for leptin, p47 phox and mir21 were used. Results showed that wild type mice that had steatohepatiic lesions, had increased oxidative stress, increased p47 phox expression, augmented f-κb activation and increased mir21 levels. These mice showed increased TGF p,

ABT-199 chemical structure SMAD2/3 phosphorylation, COL1A1 and α-SMA expression with a concomitant decrease in both miRNA and protein levels of SMAD7 (inhibitor of TGF p signaling pathway and a regulatory SMAD that is a direct target of mir21). Mice that were deficient in leptin, leptin receptor or p47 phox had decreased Nf-κb and mir21 levels suggesting the role of these proteins in inducing NFkB mediated mir21. Further mir21 ko mice had decreased TGF b signaling, increased SMAD7 levels and decreased fibrogenesis as shown by a-SMA levels and picrosirius red staining. The increased markers for stellate cell activation, collagen deposition and fibrogenesis when compared to wild type mice were decreased in mice that were deficient in leptin and p47 phox genes, suggesting that leptin mediated NADPH oxidase plays a direct role in fibrogenesis via mir21-induced inhibition of SMAD7. Interestingly macrophage depletion by GdCl3 didn’t decrease TGF p signaling or kinetics of SMAD7

expression. Taken together the studies show the novel role of leptin-NADPH oxidase- mediated regulation of mir21 in NASH and identifies mir21 as a potential therapeutic target Y-27632 2HCl of fibrogenesis in NASH. Disclosures: Anna Mae Diehl – Consulting: Roche; Grant/Research Support: Gilead, Genfit The following people have nothing to disclose: Diptadip Dattaroy, Ratanesh K. Seth, Suvarthi Das, Sahar Pourhoseini, Mitzi Nagarkatti, Gregory A. Michelotti, Saurabh Chatterjee “
“Prohibitin 1 (PHB1) is a highly conserved, ubiquitously expressed protein that participates in diverse processes including mitochondrial chaperone, growth and apoptosis. The role of PHB1 in vivo is unclear and whether it is a tumor suppressor is controversial. Mice lacking methionine adenosyltransferase 1A (MAT1A) have reduced PHB1 expression, impaired mitochondrial function, and spontaneously develop hepatocellular carcinoma (HCC).