Cu,Zn-superoxide dismutase-dependent apoptosis induced by nitric oxide in neuronal cells.
Nitric oxide (NO) challenge to human neuroblastoma cells (SH-SY5Y) ultimately results in apoptosis. Tumor suppressor protein p53 and cell cycle inhibitor p21 accumulate as an early sign of S-nitrosoglutathione-mediated toxicity. Cytochrome c release from mitochondria and caspase 3 activation also occurred. Cells transfected with either wild type (WT) or mutant (G93A) Cu, Zn-superoxide dismutase (Cu,Zn-SOD) produced comparable amounts of nitrite/nitrate but showed different degree of apoptosis. G93A cells were the most affected and WT cells the most protected; however, Cu, Zn-SOD content of these two cell lines was 2-fold the SH-SY5Y cells under both resting and treated conditions. We linked decreased susceptibility of the WT cells to higher and more stable Bcl-2 and decreased reactive oxygen species. Conversely, we linked G93A susceptibility to increased reactive oxygen species production since simultaneous administration of S-nitrosoglutathione and copper chelators protects from apoptosis. Furthermore, G93A cells showed a significant decrease of Bcl-2 expression and, as target of NO-derived radicals, showed lower cytochrome c oxidase activity. These results demonstrate that resistance to NO-mediated apoptosis is strictly related to the level and integrity of Cu,Zn-SOD and that the balance between reactive nitrogen and reactive oxygen species regulates neuroblastoma apoptosis.
Ciriolo
M R
MR
Department of Biomedical Sciences, University of Chieti "G. D'Annunzio," via dei Vestini, 66100 Chieti, Italy. Ciriolo@bio.uniroma2.it
De Martino
A
A
Lafavia
E
E
Rossi
L
L
Carrì
M T
MT
Rotilio
G
G
D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology; D017209:Apoptosis / Q000502:physiology*; D020169:Caspases / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism; D015536:Down-Regulation; D004789:Enzyme Activation; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D009474:Neurons / Q000201:enzymology / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D009603:Nitroso Compounds / Q000378:metabolism; D015689:Oncogene Protein p21(ras) / Q000378:metabolism; D018384:Oxidative Stress; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D026422:S-Nitrosoglutathione; D013482:Superoxide Dismutase / Q000502:physiology*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D003574:Cytochrome c Group; D009603:Nitroso Compounds; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D009569:Nitric Oxide; D026422:S-Nitrosoglutathione; D013482:Superoxide Dismutase; D020169:Caspases; D015689:Oncogene Protein p21(ras); D005978:Glutathione