Carbon tetrachloride (CCl4) accelerated development of non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH) in MS-NASH mice fed western diet supplemented with fructose (WDF)

Abstract

Background Multiple NAFLD/NASH murine models have been developed by obesogenic diets and/or chemical induction. MS-NASH (formally FATZO) mouse is a spontaneously developed dysmetabolic strain that can progress from hepatosteatosis to moderate fibrosis when fed western diet supplemented with 5% fructose (WDF). This study aimed to use carbon tetrachloride (CCl4) to accelerate and aggravate progression of NAFLD/NASH in MS-NASH mouse. Methods Male MS-NASH mice at 8 weeks of age were fed WDF for the entire study. Starting at 16 weeks of age, CCl4 was intraperitoneally administrated twice weekly at a dose of 0.2 mL/kg for 3 weeks or 0.08 mL/kg for 8 weeks. Obeticholic acid (OCA, 30 mg/kg, QD) was administered in both MS-NASH and C57Bl/6 mice fed WDF and treated with CCl4 (0.08 mL/kg). Results WDF enhanced obesity and hepatosteatosis, as well as induced moderate fibrosis in MS-NASH mice similar to that reported previously. Administration of CCl4 accelerated liver fibrosis with increased bridging, but no significant impact on liver steatosis and lipid contents. Compared to the high dose CCl4 at 0.2 mL/kg, the lower dose of 0.08 mL/kg caused less death and smaller elevation of ALT and AST. Compared to MS-NASH mice, C57BI/6 mice with WDF and CCl4 (0.08 mL/kg) resulted in milder hepatosteatosis and fibrosis. OCA treatment significantly lowered liver triglycerides, steatosis and fibrosis in both MS-NASH and C57Bl/6 mice treated with WDF and CCl4. Conclusions CCl4 reduced induction time and exacerbated the fibrosis in MS-NASH mice on WDF, which, thus, becomes a superior NASH model with more prominent liver pathology used favorably in pharmaceutical industry for testing novel therapeutics targeting NASH.