Treatment with a SOD mimetic reduces visceral adiposity, adipocyte death and adipose tissue inflammation in high fat fed mice

OBJECTIVE: Obesity is associated with enhanced reactive oxygen species (ROS) accumulation in adipose tissue. However, a causal role for ROS in adipose tissue expansion after high fat feeding is not established. The aim of this study is to investigate the effect of the cell permeable superoxide dismutase mimetic and peroxynitrite scavenger Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP) on adipose tissue expansion and remodeling in response to high fat diet (HFD) in mice. DESIGN AND METHODS: Male C57BL/6j mice were fed normal chow or high fat diet (HFD) and treated with saline or MnTBAP for 5 weeks. The effects of MnTBAP on body weights, whole body energy expenditure, adipose tissue morphology and gene expression were determined. RESULTS: MnTBAP attenuated weight gain and adiposity through a reduction in adipocyte hypertrophy, adipogenesis and fatty acid uptake in epididymal (eWAT) but not in inguinal (iWAT) white adipose tissue. Furthermore, MnTBAP reduced adipocyte death and inflammation in eWAT and diminished circulating levels of free fatty acids and leptin. Despite these improvements, the development of systemic insulin resistance and diabetes after HFD was not prevented with MnTBAP treatment. CONCLUSIONS: Taken together, these data suggest a causal role for ROS in the development of diet-induced visceral adiposity but not in the development of insulin resistance and type 2 diabetes.