Tumor necrosis factor-alpha and phorbol 12-myristate 13-acetate differentially modulate cytotoxic effect of nitric oxide generated by serum deprivation in neuronal PC12 cells.
Nitric oxide (NO) is a signaling molecule that mediates several physiological processes in a range of cell and tissue types. Here we investigated the effect of serum deprivation in the absence or presence of phorbol 12-myristate 1 3-acetate (PMA) or tumor necrosis factor-alpha (TNFalpha) on cell viability, NO formation, inducible NO synthase (iNOS) induction, and activation of mitogen-activated protein kinase in neuronal PC12 cells. Within 24 h of serum deprivation, apoptosis occurred in up to 65-70% of the cells, and significant levels of NO were generated. When PMA was added in serum-free medium, NO formation and cell death were decreased. In contrast, addition of TNFalpha in serum-free medium increased the levels of NO formation and apoptosis compared with those in serum-deprived cells. We have demonstrated that differential generation of NO levels by PMA or TNFalpha under conditions of serum deprivation is mediated by the same pattern of iNOS induction. NO formation via iNOS induction resulted in the activation of c-Jun N-terminal kinase (JNK) but not extracellular signal-regulated kinase. From this study it is suggested that the differential formation of cytotoxic NO by serum deprivation plus PMA or TNFalpha is primarily mediated by the induction of iNOS enzymes in neuronal PC12 cells and that its action is mediated by the activation of JNK.
Chung
K C
KC
Department of Pharmacology and Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
Park
J H
JH
Kim
C H
CH
Ahn
Y S
YS
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis / Q000378:metabolism; D002273:Carcinogens / Q000494:pharmacology*; D016895:Culture Media, Serum-Free / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D016716:PC12 Cells; D011494:Protein Kinases / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D015398:Signal Transduction / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D002273:Carcinogens; D016895:Culture Media, Serum-Free; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D013755:Tetradecanoylphorbol Acetate