Stimulation of "stress-regulated" mitogen-activated protein kinases (stress-activated protein kinases/c-Jun N-terminal kinases and p38-mitogen-activated protein kinases) in perfused rat hearts by oxidative and other stresses.
"Stress-regulated" mitogen-activated protein kinases (SR-MAPKs) comprise the stress-activated protein kinases (SAPKs)/c-Jun N-terminal kinases (JNKs) and the p38-MAPKs. In the perfused heart, ischemia/reperfusion activates SR-MAPKs. Although the agent(s) directly responsible is unclear, reactive oxygen species are generated during ischemia/reperfusion. We have assessed the ability of oxidative stress (as exemplified by H2O2) to activate SR-MAPKs in the perfused heart and compared it with the effect of ischemia/reperfusion. H2O2 activated both SAPKs/JNKs and p38-MAPK. Maximal activation by H2O2 in both cases was observed at 0.5 mM. Whereas activation of p38-MAPK by H2O2 was comparable to that of ischemia and ischemia/reperfusion, activation of the SAPKs/JNKs was less than that of ischemia/reperfusion. As with ischemia/reperfusion, there was minimal activation of the ERK MAPK subfamily by H2O2. MAPK-activated protein kinase 2 (MAPKAPK2), a downstream substrate of p38-MAPKs, was activated by H2O2 to a similar extent as with ischemia or ischemia/reperfusion. In all instances, activation of MAPKAPK2 in perfused hearts was inhibited by SB203580, an inhibitor of p38-MAPKs. Perfusion of hearts at high aortic pressure (20 kilopascals) also activated the SR-MAPKs and MAPKAPK2. Free radical trapping agents (dimethyl sulfoxide and N-t-butyl-alpha-phenyl nitrone) inhibited the activation of SR-MAPKs and MAPKAPK2 by ischemia/reperfusion. These data are consistent with a role for reactive oxygen species in the activation of SR-MAPKs during ischemia/reperfusion.
Clerk
A
A
National Heart and Lung Institute Division, Imperial College School of Medicine, Royal Brompton Campus, London SW3 6LY, United Kingdom.
Fuller
S J
SJ
Michael
A
A
Sugden
P H
PH
D000595:Amino Acid Sequence; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D008297:Male; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D017202:Myocardial Ischemia / Q000201:enzymology; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000201:enzymology*; D018384:Oxidative Stress; D010477:Perfusion; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2
D017871:Calcium-Calmodulin-Dependent Protein Kinases; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D006861:Hydrogen Peroxide; D007093:Imidazoles; D047908:Intracellular Signaling Peptides and Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011725:Pyridines; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C093642:SB 203580