Manganese superoxide dismutase (MnSOD), also named as SOD2, is a mitochondrial detoxification enzyme that catalyzes the conversion of superoxide to hydrogen peroxide. Hydrogen peroxide is then decomposed to water by catalase, glutathione peroxidase, or peroxiredoxins. MnSOD and other enzymes involved in antioxidant defense protect cells from reactive oxygen species (ROS). Calorie restriction leads to SIRT3-mediated deacetylation of MnSOD and the subsequent increase of its antioxidant activity. MnSOD also plays an essential role in mediating the protective effect of mTOR inhibition to reduce epithelial stem cell senescence.
