title: p38 Triggers late preconditioning elicited by anisomycin in heart: involvement of NF-kappaB and iNOS.
abstract: We investigated the role of stress-activated p38 MAP kinase (p38/SAPK-2) signaling in delayed preconditioning of the heart. Adult male out-bred ICR mice were treated with p38 activator, anisomycin (0.1 mg/kg IP), or vehicle (5% DMSO). Twenty-four hours later, hearts were perfused in Langendorff mode and subjected to 30 minutes of ischemia and 30 minutes of reperfusion. Improvement in postischemic recovery of end-diastolic pressure and reduction in infarct size was observed, which was abolished by SB203580, a specific p38 inhibitor, and pyrrolidinediethyldithiocarbamate (PDTC), the NF-kappaB inhibitor, but not by PD 98059, a specific inhibitor for MEK1 or 2. Transient increase in p38 phosphorylation was observed 15 minutes after anisomycin treatment which subsided by 30 minutes. Electrophoretic mobility shift assay demonstrated rapid activation of NF-kappaB DNA binding with anisomycin, peaking at 30 minutes. Western blot confirmed the accumulation of p50 and p65 in nuclear extracts after anisomycin treatment. Anisomycin-induced NF-kappaB DNA binding activity was inhibited by SB203580 and PDTC. Expression of inducible nitric oxide synthase (iNOS) mRNA, protein, and nitric oxide (NO) synthesis were enhanced in anisomycin-treated mice. SB203580 and PDTC blocked the increased expression of iNOS and increase in synthesis of NO. Selective iNOS inhibitor S-methylisothiourea abolished the protective effect of anisomycin. Furthermore, postischemic cardioprotective effect of anisomycin was absent in mice with targeted ablation of iNOS gene but not in the wild-type B6.129 mice. For the first time, these results suggest that direct pharmacological activation of p38 triggers delayed preconditioning by signaling mechanism involving NF-kappaB activation and synthesis of NO from iNOS.
authors.affiliation: Division of Cardiology, Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Zhao
authors.forename: M M
authors.initials: MM
authors.lastname: Taher
authors.forename: K C
authors.initials: KC
authors.lastname: Valerie
authors.forename: R C
authors.initials: RC
authors.lastname: Kukreja
mesh_terms: D000818:Animals; D000841:Anisomycin / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009203:Myocardial Infarction / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D017202:Myocardial Ischemia / Q000150:complications; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016276:Ventricular Function / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D009569:Nitric Oxide; D000841:Anisomycin; D004247:DNA; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases