805 Knockout of SULF2 Significantly Ameliorates Hypercholesterolemia, Steatohepatitis and Liver Fibrosis in Obese Mice Fed a Fast Food Diet

Background: Nonalcoholic fatty liver disease (NAFLD), an important consequence of metabolic disorders such as obesity and type 2 diabetes (T2DM), has become highly prevalent in the US, and is now an important public health concern. Recent reports have identified the heparan sulfate degrading endosulfatase sulfatase 2 (Sulf2) as a suppressor of triglyceriderich lipoprotein (TRL) remnant clearance by hepatocytes in T2DM mice, thus enhancing postprandial hypertriglyceridemia. Further, inhibition of Sulf2 normalized the VLDL-binding capacity of hepatocytes from T2DM mice and abolished postprandial hypertriglyceridemia. We hypothesized that an increase in hepatic Sulf2 occurring during insulin resistance states such as obesity and T2DM decreases hepatic clearance of TRL remnants and contributes to the development of NAFLD, which can be characterized by non-alcoholic steatohepatitis (NASH) and liver fibrosis. Aims: To investigate (1) whether a fast food diet high in saturated fats, cholesterol, and fructose can produce insulin resistance and overexpression of Sulf2; and (2) whether depletion of Sulf2 can protect against NASH and liver fibrosis in obese mice on a fast food diet. Methods: Sulf2 knockout and wild-type mice (n=12 each) were fed a fast food diet rich in saturated fats and cholesterol along with fructose in their drinking water or normal rodent chow with tap water, beginning at 6-8 weeks of age. At 9 months, mice were sacrificed, blood was obtained for assessment of insulin resistance, alanine transaminase (ALT) and serum lipids, and the livers were harvested and examined for steatosis, steatohepatitis, and fibrosis. Results: The fast food diet produced obesity and insulin resistance. Sulf2 knockout mice fed the fast food diet had significantly less weight gain and lower serum ALT, total cholesterol and LDL-cholesterol than wild-type mice (p,0.05). The fast food diet also induced histopathological features of NASH, including hepatic microvesicular steatosis, inflammation and fibrosis. Hepatic fibrosis was significantly decreased in Sulf2 knockout mice compared to controls (p,0.05). Conclusions: Depletion of Sulf2 improves hypercholesterolemia, steatohepatitis and hepatic fibrosis in a mouse model of NASH induced by a fast food diet. Inhibition of SULF2 may be a potential preventive and therapeutic strategy for NASH with progressive fibrosis.