The expression levels of LC3-II and P62 were increased by PA,
suggesting that PA inhibits the autophagic process after autophagosome formation. PA also increased the expression level of Rubicon, a negative regulator of autophagosome-lysosome fusion. The inhibition of autophagy by PA was observed earlier (4h) than PA-induced apoptosis (8h). To examine the effect of learn more PA’s autophagy inhibition on apoptosis, HepG2 cells were transfected with siRNA against Atg7 or Rubicon, followed by PA treatment. Autoph-agy inhibition by Atg7 konckdown exacerbated PA-induced apoptosis. Interestingly, Rubicon knockdown clearly abolished PA-induced inhibition of autophagic flux, reduced ER stress and ameliorated PA-induced apoptosis. Consistent with in vitro findings, mice on HFD for 3 months or more showed increased hepatocyte apoptosis compared with mice on control diet, evidenced by increase in serum ALT levels or caspase-activity and TUNEL-positive cells in the liver. Rubicon expression was increased for 1 month or more and increase of LC3-II and P62 were observed in murine livers on HFD for 2 months or more. Injection of PolyI:C into Mx1-Cre Atg7 fl/fl mice which had been given 1 month HFD inhibited liver autophagy and clearly induced live injury as evidenced by increase in serum ALT levels and TUNEL-positive hepatocytes
accompanied by JNK activation. siRNA-mediated in vivo knockdown of Rubicon ameliorated autophagy inhibition in livers of mice on HFD for 4 months. It inhibited ER stress and hepatocyte apoptosis. Conclusion: Increased expression
of Rubicon induced by HFD, as well as PA, suppresses click here autophagic flux and promotes hepatocyte apoptosis by increasing ER stress. Enhancement of autophagy by inhibiting Rubicon 上海皓元医药股份有限公司 may provide new approaches for treatment of NAFLD. Disclosures: Tetsuo Takehara – Grant/Research Support: Chugai Pharmaceutical Co., MSD K.K. The following people have nothing to disclose: Satoshi Tanaka, Hayato Hikita, Yasutoshi Nozaki, Yugo Kai, Tasuku Nakabori, Yoshinobu Saito, Ryotaro Saka-mori, Takuya Miyagi, Naoki Hiramatsu, Tomohide Tatsumi Obesity, insulin resistance, and diabetes have become the leading causes of renal and nonalcoholic fatty liver disease (NAFLD), and nonalcoholic steatohepatitis (NASH). Currently, there is no established therapy of NASH. Lifestyle alterations including diet and exercise often fail to prevent or reverse NASH. The purpose of the present study was to determine if in mice fed a Western (high fat, high sucrose, cholesterol) diet with established obesity, insulin resistance, NAFLD, and NASH, treatment with the dual agonist of the nuclear receptor the farnesoid X receptor (FXR) and the G protein coupled receptor TGR5, 6α-ethyl-3α,7α,23-trihydroxy-24-nor-5β-cholan-23-sulfate sodium salt (INT-767) decreases the progression of liver disease.