The N-terminal domain of gasdermin D induces liver fibrosis by reprogrammed lipid metabolism

Background: The emerging incidence of pathogenic liver conditions is turning into a major concern for global health. Induction of pyroptosis in hepatocytes instigates cellular disintegration, which in turn liberates substantial quantities of pro-inflammatory intracellular substances, thereby accelerating the advancement of liver fibrosis. Consequently, directing therapeutic efforts towards inhibiting pyroptosis could potentially serve as an innovative approach in managing inflammation related chronic hepatic disorders.

Methods: GSDMD-NT^ki/wt mice and Alb-cre^ki/wt mice were generated using CRISPR/Cas9 technology. After crossing the two strains together, we induced conditional cell death by doxycycline to construct a mouse model of liver fibrosis. We analyzed differentially expressed genes by RNA sequencing and explored their biological functions. The efficacy of obeticholic acid (OCA) in the treatment of liver fibrosis was assessed.

Results: Doxycycline-treated GSDMD-NT^ki/wt × Alb-cre^ki/wt mice showed severe liver damage, vacuolation of hepatocytes, increased collagen fibers, and accumulation of lipid droplets. The expression of liver fibrosis related genes was greatly increased in the doxycycline-treated mouse liver compared with untreated mouse liver. RNA-sequencing showed that upregulated differentially expressed genes were involved in inflammatory responses, cell activation, and metabolic processes. Treatment with OCA alleviated the liver fibrosis, with reduced ALT and AST levels seen in the GSDMD-NT^ki/wt × Alb-cre^ki/wt mice.

Conclusions: We successfully constructed a novel mouse model for liver fibrosis. This GSDMD-NT-induced fibrosis may be mediated by abnormal lipid metabolism. Our results demonstrated that we successfully constructed a mouse model of liver fibrosis, and GSDMD-NT induced fibrosis by mediating lipid metabolism.