Silencing of functional p53 attenuates NAFLD by promoting HMGB1-related autophagy induction

Background and aim Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease worldwide, but its pathogenesis remains imprecisely understood and requires further clarification. Recently, the tumor suppressor p53 has received growing attention for its role in metabolic diseases. In this study, we performed in vivo and in vitro experiments to identify the contribution of p53–autophagy regulation to NAFLD. Methods Livers from wild-type and p53 knockout mice as well as p53-functional HepG2 cells and p53-dysfunctional Huh7 cells were examined for autophagy status and HMGB1 translocation. In vivo and in vitro NAFLD models were established, and steatosis was detected. In the cell models, autophagy status and steatosis were examined by p53 and/or HMGB1 silencing. Results First, the silencing of p53 could induce autophagy both in vivo and in vitro. In addition, p53 knockout attenuated high-fat diet-induced NAFLD in mice. Similarly, knockdown of p53 could alleviate palmitate-induced lipid accumulation in cell models. Furthermore, high mobility group box 1 (HMGB1) was proven to contribute to the effect of silencing p53 on alleviating NAFLD in vitro as an autophagy regulator. Conclusion The anti-NAFLD effect of functional p53 silencing is associated with the HMGB1-mediated induction of autophagy. Graphic abstract