Effects of maternal cigarette smoke exposure on the progression of nonalcoholic steatohepatitis in offspring mice

Cigarette smoke (CS) is a dominant carcinogenic agent in a variety of human cancers. CS exposure during pregnancy can adversely affect the fetus. Non-alcoholic fatty liver disease (NAFLD) is considered as a hepatic manifestation of a metabolic disorder, and ranges from simple steatosis to cirrhosis leading to hepatocellular carcinoma. Non-alcoholic steatohepatitis (NASH) is a more severe phase of NAFLD. Recently, there is increasing apprehension about the CS-related chronic liver diseases. Therefore, we examined whether maternal CS exposure could affect the pathogenesis of NASH in offspring. Mainstream CS (MSCS) was exposed to pregnant C57BL/6 mice via nose-only inhalation for 2 h/day, 5 days/week for 2 weeks from day 6 to 17 of gestation at 0, 300, or 600 mu g/L. Three-week-old male offspring mice were fed methionine and choline-supplemented (MCS) diet or methionine and choline-deficient including high-fat (MCDHF) diet for 6 weeks to induce NASH. Maternal MSCS exposure increased the severity of NASH by increasing serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, hepatic total cholesterol (TC) and triglyceride (TG) levels, pro-inflammation, fibrosis, and steatosis in offspring mice. Especially, maternal MSCS exposure significantly downregulated the phosphorylation of AMP-activated protein kinase (AMPK) in MCDHF diet-fed offspring mice. Subsequently, the protein levels of sterol regulatory element-binding protein (SREBP)-1c and stearoyl-CoA desaturase-1 (SCD1) were upregulated by maternal MSCS exposure. In conclusion, maternal MSCS exposure exacerbates the progression of NASH by modulating lipogenesis on offspring mice.