Glutathione depletion in fibroblasts is the basis for apoptosis-induction by endogenous reactive oxygen species

Abstract

Our study aimed at clarifying the role of the intracellular concentration of reduced glutathione for induction of apoptosis in fibroblasts. Treatment of fibroblasts with buthionine sulfoximine (BSO) caused efficient depletion of intracellular reduced glutathione which was followed by substantial cell death. Based on the induction of membrane blebbing, chromatin condensation and DNA strand breaks, cell death was characterized as apoptosis. Apoptosis after glutathione depletion seemed to be induced by endogenous reactive oxygen species (ROS), as it was antagonized by the antioxidant catechol and the hydroxyl radical scavenger DMSO. Paracrine interaction between cells prevented ROS-induced apoptosis and therefore points to the existence of extracellular survival factors. Our data show that the apoptosis-inducing potential of endogenous ROS is controlled by the intracellular glutathione concentration and by paracrine survival factors.