Involvement of p38 mitogen-activated protein kinase and apoptosis signal-regulating kinase-1 in nitric oxide-induced cell death in PC12 cells.

Although nitric oxide (NO) plays key signaling roles in the nervous systems, excess NO leads to cell death. In this study, the involvement of p38 mitogen-activated protein kinase (p38 MAPK) and apoptosis signal-regulating kinase-1 (ASK1) in NO-induced cell death was investigated in PC12 cells. NO donor transiently activated p38 MAPK in the wild type parental PC12 cells, whereas the p38 MAPK activation was abolished in NO-resistant PC12 cells (PC 12-NO-R). p38 MAPK inhibitors protected the cells against NO-induced death, whereas the inhibitors were not significantly protective against the cytotoxicity of reactive oxygen species. Stable transfection with dominant negative p38 MAPK mutant reduced NO-induced cell death. Stable transfection with dominant negative mutant of ASK1 attenuated NO-stimulated activation of p38 MAPK and decreased NO-induced cell death. These results suggest that p38 MAPK and its upstream regulator ASK1 are involved in NO-induced PC12 cell death.