Targeting of miR-96-5p by Catalpol Ameliorates Oxidative Stress and Hepatic Steatosis in LDLr-/- Mice via p66shc/Cytochrome C Cascade

Background: Hepatic steatosis and oxidative stress are considered to sequential steps in the development of non-alcoholic fatty liver disease (NAFLD). We previously found the protective effects of catalpol, an iridoid glucoside extracted from the root of Romania glutinosa L. Here, the increase expression of p66shc was found in NAFLD models and catalpol could inhibit p66shc expression ameliorating NAFLD effectively. Then, we investigated p66shc-targeting miRNAs in regulating oxidative stress and hepatic steatosis, and the potential role of p66shc in NAFLD. Methods: An NAFLD animal model established by low density lipoprotein receptor knockout (LDLr-/-) mice fed with high fat diet and cellular model by palmitic acid -treated hepG2 cells were employed to investigate the role of catalpol on NAFLD and the underling mechanism miR-96-5p involve in. With histological analysis, western blot, qPCR and transfection assay, identified miR-96-5p as being strongly differentially expressed between NAFLD and normal individuals and catalpol can ameliorate NAFLD via increasing miR-96-5p expression. Findings: We found that p66Shc, a protein induced by oxidative stress was significantly increased in NAFLD. Results also show that high level of p66shc is correlated with oxidative stress and hepatic steatosis. Moreover, targeting miR-96-5p by catalpol ameliorates oxidative stress and hepatic steatosis in LDLr-/- mice via p66shc/cytochrome C cascade. Interpretation: These data identify a role for miR-96-5p in NAFLD through inhibiting oxidative stress and hepatic steatosis via p66shc/cytochrome C cascade and the role of catalpol involve in. Funding Statement: This work was supported by grants from the Chinese National Natural Science Foundation (No.81273508). Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: All experiments were approved by the Animal Care and Use Committee of Dalian Medical University, and the experimental procedures were performed in strict accordance with Legislation Regarding the Use and Care of Laboratory Animals of China.