UCP3 overexpression neutralizes oxidative stress rather than nitrosative stress in mouse myotubes

Abstract

The deleterious effects of oxidants on proteins may be modified by overexpression of uncoupling protein 3 (UCP3) in skeletal muscle cells exposed to hyperoxia or H 2O 2. UCP3 overexpression significantly attenuated the increase in protein carbonylation in response to hyperoxia and H 2O 2 exposures. However, antioxidant enzyme content and activity (superoxide dismutases, peroxiredoxins, glutathione peroxidase-I, and catalase) were reduced or not modified in UCP3-overexpressing myotubes exposed to oxidants. Protein nitration increased in UCP3-overexpressing cells exposed to hyperoxia, but not to H 2O 2. We conclude that protein oxidation rather than nitration is neutralized by UPC3 overexpression in mouse myotubes exposed to abundant reactive oxygen species.