BACKGROUND: Massive hepatocyte death is the core event in acute liver failure (ALF). Gasdermin D (GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death. However, the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.
AIM: To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis throughandexperiments. in vitro in vivo
METHODS: The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot. GSDMD short hairpin RNA (shRNA) was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1 (MCP1) and its receptor CC chemokine receptor-2 (CCR2). Forexperiments, we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide (D-Galn/LPS)-induced ALF mouse model. in vitro in vivo
RESULTS: The levels of pyroptosis pathway-associated proteins in liver tissue from ALF patients and a hepatocyte injury model increased significantly. The level of GSDMD-N protein increased most obviously (< 0.001)., downregulation of GSDMD by shRNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins (< 0.01)., GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of D-Galn/LPS-induced ALF mice (< 0.001). Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin (IL)-1β and IL-18, GSDMD-mediated hepatocyte pyroptosis recruited macrophagesMCP1/CCR2 to aggravate hepatocyte death. However, this pathological process was inhibited after knocking down GSDMD. P In vitro P In vivo P via
CONCLUSION: GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF, recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses. GSDMD knockout can reduce hepatocyte death and inflammatory responses, thus alleviating ALF.
