부산대학교 도서관

Upon exposure to excessive reactive oxygen species (ROS), organismal survival depends on the strength of the endogenous antioxidant defense barriers that prevent mitochondrial and cellular deterioration. Previously, we showed that glycolic acid can restore the mitochondrial membrane potential of C. elegans treated with paraquat, an oxidant that produces superoxide and other ROS species, including hydrogen peroxide. Here, we demonstrate that glycolate fully suppresses the deleterious effects of peroxide on mitochondrial activity and growth in worms. This endogenous compound acts by entering serine/glycine metabolism. In this way, conversion of glycolate into glycine and serine ameliorates the drastically decreased NADPH/NADP+ and GSH/GSSG ratios induced by H2O2 treatment. Our results reveal the central role of serine/glycine metabolism as a major provider of reducing equivalents to maintain cellular antioxidant systems and the fundamental function of glycolate as a natural antioxidant that improves cell fitness and survival. Diez et al. show that glycolate suppresses deleterious effects of peroxide on mitochondrial activity and growth of worms. They find that the conversion of glycolate into glycine and serine helps worms maintain cellular antioxidants following oxidative stress. This study suggests that glycolate serves as a natural antioxidant improving organismal fitness under stress. [ABSTRACT FROM AUTHOR]