GLUTATHIONE LEVELS DETERMINE APOPTOSIS IN MACROPHAGES

Spermine NONOate (SpNO, a nitric oxide donor) induced apoptosis and ca spase-3 activity in the macrophage cell line RAW 267.4, RES cells that have been derived from RAW 267.4 cells by repeated exposure to lipopo lysaccharide and interferon-gamma (LPS/INF-gamma), followed by outgrow th of viable cells, are resistant to apoptosis and caspase-3 activatio n upon exposure to SpNO, In this study we have determined that RES cel ls have lower levels of glutathione (GSH) and a higher oxidative state than RAW cells. Subsequently, RAW and RES cells were depleted of GSH by using 1-buthionine-[S,R]-sulfoximine (BSO), a specific inhibitor of GSH synthesis. GSH depleted cells did not undergo apoptosis nor demon strate caspase-3 activity when they were exposed to SpNO. These result s suggest that the redox status of the cell is one of the key factors mediating the apoptotic pathway in which glutathione plays a critical role in mediating apoptosis via NO. and reactive oxygen species (ROS). (C) 1998 Academic Press.