NOX3-derived reactive oxygen species promote TNF-α-induced reductions in hepatocyte glycogen levels via a JNK pathway

TNF-α-induced insulin resistance is associated with generation of reactive oxygen species (ROS). This study aims at defining the link between ROS production and hepatic insulin resistance. Treatment with TNF-α increased ROS generation through activating NADPH oxidase 3 (NOX3) in HepG2 hepatocytes. Down-regulation of NOX3 using siRNA prevented TNF-α-induced decrease of cellular glycogen. In the cells treated with TNF-α, there were NOX3-dependent activation of JNK, inhibition of IRS1 and phosphorylation of AKT/PKB and GSK. In conclusion, the effects of TNF-α on hepatic insulin resistance appear to be, at least in part, mediated by NOX3-derived ROS through a JNK pathway.