Atorvastatin attenuates diet-induced non-alcoholic steatohepatitis in APOE*3-Leiden mice by reducing hepatic inflammation

Abstract: Patients with metabolic syndrome are often prescribed statins to prevent development of 17 cardiovascular disease. Conversely, data on their effects on non-alcoholic steatohepatitis (NASH) 18 are lacking. We evaluated these effects by feeding APOE*3-Leiden mice a Western-type diet (WTD) 19 with or without atorvastatin to induce NASH and hepatic fibrosis. Besides the well-known plasma 20 cholesterol lowering (-30%) and anti-atherogenic effects (severe lesion size -48%), atorvastatin sig-21 nificantly reduced hepatic steatosis (-22%), the number of aggregated inflammatory cells in the liver 22 (-80%) and hepatic fibrosis (-92%) compared to WTD-fed mice. Furthermore, atorvastatin-treated 23 mice showed less immunohistochemically stained area of inflammation markers. Atorvastatin pre-24 vented accumulation of free cholesterol in the form of cholesterol crystals (-78%). Cholesterol crys-25 tals are potent inducers of the NLRP3 inflammasome pathway and atorvastatin prevented its acti-26 vation, which resulted in reduced expression of the pro-inflammatory cytokines interleukin (IL)-1β 27 (-61%) and IL-18 (-26%). Transcriptome analysis confirmed strong reducing effects of atorvastatin 28 on inflammatory mediators, including NLRP3, NFκB and TLR4. The present study demonstrates 29 that atorvastatin reduces hepatic steatosis, inflammation and fibrosis and prevents cholesterol crys-30 tal formation, thereby precluding NLRP3 inflammasome activation. This may render atorvastatin 31 treatment as an attractive approach to reduce NAFLD and prevent progression into NASH in 32 dyslipidemic patients. The study contains 3 diet groups: Chow, WTD and WTD+Atorvastatin. Female APOE*3-Leiden mice (8-14 weeks old) were fed a semi-synthetic Western-type diet (WTD) for a run-in period of three weeks to start the induction of NASH and fibrosis. From baseline and onward (t = 0-32 weeks), the group was split in two and fed with or without atorvastatin as admixture to the WTD. A healthy reference mice group was kept on a maintenance chow diet. At 32 weeks mice were sacrified and blood and organs were collected for analysis.