Activation of hepatic stellate cells (HSCs) is a prominent driver of liver fibrogenesis, including alcoholic liver fibrosis (ALF). Furthermore, autophagy contributes to HSCs activation. This study aims to investigate the role and the mechanisms of long noncoding RNA XIST in regulating HSCs autophagy and activation. Human HSC cells (LX-2) were treated with 100 mmol/L ethanol to mimic HSCs activation. The HSCs activation was evaluated by determining cell viability and protein levels of fibrosis markers α-smooth muscle actin (α-SMA) and collagen type 1 α1 (CoL1A1). The autophagy was evaluated by measuring autophagy markers Beclin-1 and LC3-II. The interaction among XIST, miR-29b, and high-mobility group box-1 (HMGB1) were analyzed using luciferase reporter assay, qRT-PCR, and western blot. Lentiviruses targeting sh-XIST (LV-sh-XIST) were injected into ALF model mice via tail vein to elucidate the in vivo role of XIST in ALF injury. XIST was upregulated in ethanol-activated LX-2 cells. Furthermore, XIST served as a competitive endogenous RNA of miR-29b to facilitate HMGB1 expression, and thus enhanced ethanol-induced HSCs autophagy and activation. Further in vivo assay showed that downregulation of XIST by LV-sh-XIST alleviated ALF injury in ALF model mice. Collectively, XIST enhances ethanol-induced HSCs autophagy and activation via miR-29b/HMGB1 axis.
Keywords: HMGB1; XIST; autophagy; hepatic stellate cells activation; miR-29b.
© 2019 International Union of Biochemistry and Molecular Biology.