High-content hydrogen water-induced downregulation of miR-136 alleviates non-alcoholic fatty liver disease by regulating Nrf2 via targeting MEG3

This study was aimed to investigate the potential regulatory mechanism of high-content hydrogen water (HHW) in non-alcoholic fatty liver disease (NAFLD). A high-fat diet (HFD)-induced NAFLD mice model and cellular model were prepared. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total cholesterol (TCH) and triglycerides (TG) were measured. The expression levels of representative five microRNA (miRNAs) (miR-103, miR-488, miR-136, miR-505 and miR-148a) in liver tissues were determined by quantitative real-time PCR (qRT-PCR). The target of miR-136 was validated by RNA immunoprecipitation (RIP) and pull-down assay. MiR-136, MEG3 and nuclear factor erythroid 2-related factor 2 (Nrf2) expression levels following cell treatment were detected in hepatocytes using qRT-PCR and Western blotting. Moreover, cell viability and TG content were conducted. MiR-136 was downregulated, MEG3 as well as Nrf2 was upregulated and serum lipid level was reduced in NAFLD mice model after HHW treatment, which exerted the same effect in cellular model. RIP and RNA pull-down assay confirmed that MEG2 was a downstream target of miR-136. What's more, HHW ameliorated lipid accumulation by regulating miR-136/MEG3/Nrf2 axis in vitro and in vivo. Hence, HHW alleviated NAFLD by downregulation of miR-136 through mediating Nrf2 via targeting MEG3.