SURVIVAL FACTOR-INSENSITIVE GENERATION OF REACTIVE OXYGEN SPECIES INDUCED BY SERUM DEPRIVATION IN NEURONAL CELLS

To investigate the involvement of reactive oxygen species (ROS) in neu ronal apoptosis, we performed confocal and flow cytometric analysis wi th a ROS-specific fluorogen, 6-carboxy-2',7'-dichorodihydrofluorescein diacetate, di(acetoxymethyl ester) (C-DCDHF-DA). Serum deprivation si gnificantly increased the level of ROS in PC12 cells and rat cortical neurons. N,N'-diphenyl-p-phenylenediamine (DPPD), an antioxidant, redu ced ROS production induced by serum deprivation and recovered cell sur vival. However, some survival factors such as nerve growth factor and Bcl-2, which prevented the apoptosis of PC12 cells, did not affect the up-regulation of ROS induced by serum deprivation. Epidermal growth f actor which prevented the apoptosis of cortical neurons, did not affec t the increase of ROS. These data suggest that survival factors rescue the serum deprivation-induced apoptosis independently of ROS producti on.