Hydrogen peroxide activation of multiple mitogen-activated protein kinases in an oligodendrocyte cell line: role of extracellular signal-regulated kinase in hydrogen peroxide-induced cell death.
Oxidative stress is known to induce cell death in a wide variety of cell types, apparently by modulating intracellular signaling pathways. In this study, we have examined the activation of mitogen-activated protein kinase (MAPK) cascades in relation to oxidant-induced cell death in an oligodendrocyte cell line, central glia-4 (CG4). Exposure of CG4 cells to hydrogen peroxide (H2O2) resulted in an increased tyrosine phosphorylation of several protein species, including the abundantly expressed platelet-derived growth factor (PDGF) receptor and the activation of the three MAPK subgroups, i.e., extracellular signal-regulated kinase (ERK), p38 MAPK, and c-Jun N-terminal kinase (JNK). Dose-response studies showed differential sensitivities of PDGF receptor phosphorylation (>1 mM) and ERK/p38 MAPK (>0.5 mM) and JNK (>0.1 mM) activation by H2O2. The activation of ERK was inhibited by PD98059, a specific inhibitor of the upstream kinase, MAPK or ERK kinase (MEK). H2O2 also activated MAPK-activated protein kinase-2, and this activation was blocked by SB203580, a specific inhibitor of p38 MAPK. The oxidant-induced cell death was indicated by morphological changes, decreased 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction, and DNA fragmentation. These effects were suppressed dose-dependently by the MEK inhibitor PD98059. The results demonstrate that H2O2 induces the activation of multiple MAPKs in oligodendrocyte progenitors and that the activation of ERK is associated with oxidant-mediated cytotoxicity.
Bhat
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NR
Department of Neurology, Medical University of South Carolina, Charleston 29425, USA.
Zhang
P
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D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000032:analysis / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D053938:DNA Fragmentation; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology; D015151:Immunoblotting; 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; D009836:Oligodendroglia / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress / Q000502:physiology; D011494:Protein Kinases / Q000032:analysis / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D016877:Oxidants; D011725:Pyridines; D006861:Hydrogen Peroxide; 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; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one