GSE201906
The imprinted gene Zac1 regulates steatosis in developmental cadmium-induced non-alcoholic fatty liver disease
Background and Aims: Cadmium (Cd) exposure in adulthood is associated with non-alcoholic fatty liver disease (NAFLD), characterized by steatosis, inflammation, and fibrosis. NAFLD is the leading type of chronic liver disease, resulting in $103 billion per year in medical costs and affecting 30 % of the adult US population. Diagnosis of NAFLD is occurring at increasingly younger ages, with up to 20 % of adolescents and young adults currently affected, suggesting that susceptibility to NAFLD may be programmed by the environment during early life. However, the role of developmental Cd exposure in programming NAFLD and the underlying mechanisms remain unclear. We have proposed that imprinted genes are strong candidates for connecting the early life environment and later disease. Approach and Results: We established a hybrid mouse model of developmental Cd exposure in which dams were exposed to 0 or 50 ppm CdCl2 five weeks prior to mating until their offspring reached postnatal day (PND) 10. CdCl2 exposure is associated with histological, biochemical, and molecular signatures of hepatic steatosis and fibrosis in juvenile mice. Using RNA-seq, we show that the Imprinted Gene Network (IGN), including its regulator Zac1, is up-regulated and over-represented among differentially expressed genes, consistent with a role in developmental Cd-induced NAFLD. In support of this, we show that hepatocyte-specific over-expression of Zac1 is sufficient to drive lipid accumulation in vitro. Conclusions: Our findings demonstrate that developmental CdCl2 exposure is sufficient to program NAFLD in later life, and with our previous work, establish Zac1 and the IGN as key regulators of prosteatotic and profibrotic pathways, two of the major pathological hallmarks of NAFLD Overall design: Liver mRNA profiles from PND0 and PND21 mice exposed to 0 or 50 ppm CdCl2 from gestation through PND10