Complementary Action of Antioxidant Enzymes in the Protection of Bioengineered Insulin-Producing RINm5F Cells Against the Toxicity of Reactive Oxygen Species

摘要

To determine the importance of different antioxidative enzymes for the defense status of insulin-producing cells, the effects of stable overexpression of glutathione peroxidase (Gpx(0, catalase(Cat), or Cu/Zn superoxide dismutase (SOD) in insulin-producing RINm5F cells on the cytotoxicity of hydrogen peroxide (H_2O_2), hypoxan- thine/xanthine oxidase (H/XO), and menadione have been investigated. Single overexpression of Cat or Gpx provided less protection than the combined expression of Cat plus SOD or Cat plus Gpx, while single overex- pression of SOD either had no effect on the toxicity of the test compounds or increased it.