Overexpression of superoxide dismutase 3 gene blocks high-fat diet-induced obesity, fatty liver and insulin resistance.

Oxidative stress has an important role in the development of obesity and obesity-associated metabolic disorders. As an endogenous antioxidant enzyme, superoxide dismutase 3 (SOD3) has the potential to affect diet-induced obesity and obesity-associated complications. In the current work, we overexpressed SOD3 in C57BL/6 mice fed a high-fat diet (HFD) to study its effect on HFD-induced obesity, fatty liver and insulin resistance. We demonstrated that the Sod3 gene transfer blocked HFD-induced obesity, fatty liver and insulin resistance. Real-time PCR analysis of adipose and liver tissues revealed that overexpression of the Sod3 gene suppressed expression of pro-inflammatory genes in adipose tissue including F4/80, Tnfα, Cd11c, Mcp1 and Il6, and increased expression of anti-inflammatory genes such as adiponectin. In the liver, high levels of SOD3 activity in animals enhanced expression of the genes responsible for energy expenditure including Cpt1α, Cpt1β, Pgc1α, Pgc1β and Ucp2. These results suggest that overexpression of the Sod3 gene through gene transfer is an effective approach in preventing diet-induced obesity and obesity-associated complications.