Mesenchymal stem cells-derived exosomal miR-24-3p ameliorates non-alcohol fatty liver disease by targeting Keap-1

Abstract

The prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing worldwide with ill-defined etiology and pathogenesis, and no approved effective therapy is presently available. Exosome-dependent intercellular communication has been identified as a potential signaling involved in tissue repair. Unfortunately, the exact influence and underlying mechanism of mesenchymal stem cells (MSCs)-derived exosome (Exo) in modulating fatty liver have not been well determined. Here in our study, in vitro results initially showed that human umbilical cord-derived mesenchymal stem cells (hUC-MSCs)-derived Exo treatment significantly suppressed lipid accumulation, reactive oxygen species (ROS) generation and inflammatory response in palmitate (PA)-stimulated mouse hepatocytes. Consistently, MSCs-derived Exo administration strongly ameliorated metabolic disorders, hepatic dysfunction and steatosis in high fat diet (HFD)-induced mouse model with NAFLD. Furthermore, Exo derived from MSCs significantly alleviated hepatic lipid metabolism disturbance, inflammation and oxidative stress induced by HFD. Exo treatment resulted in a stronger increase in miR-24-3p expression in hepatocytes. Reducing miR-24-3p in MSCs markedly abrogated the protective effects of Exo in hepatocytes under PA stimulation. Mechanistically, miR-24-3p directly targeted Kelch-like ECH-associated protein 1 (Keap-1), and suppressed its expression. In addition, the effects of MSCs-derived exosomal miR-24-3p to restrain lipid accumulation, ROS generation and inflammation in vitro were largely Keap-1 dependent via Keap-1 depression. Collectively, our study demonstrated that MSCs-derived exosomal miR-24-3p had hepaprotective effects through targeting Keap-1 signaling, providing a potential therapeutic value for NAFLD treatment.