Glycogen synthase kinase-3beta/beta-catenin promotes angiogenic and anti-apoptotic signaling through the induction of VEGF, Bcl-2 and survivin expression in rat ischemic preconditioned myocardium.
Ischemic preconditioning (IP) enhances vascular endothelial growth factor (VEGF), Bcl-2 and survivin expression after myocardial infarction (MI). Mechanisms of angiogenic and anti-apoptotic effects due to IP still remain unclear. The present study attempts to address whether GSK-3beta-beta-catenin signaling in turn interacts with T-cell transcription factor/lymphoid-enhancer binding factor (TCF/LEF) and regulates these genes in the ischemic preconditioned myocardium. In a rat MI model with permanent occlusion of left anterior descending coronary artery (LAD), IP (four cycles of 4-min of ischemia and 4-min of reperfusion) significantly phosphorylated and inhibited GSK-3beta and accumulated beta-catenin in the cytosol and nucleus. Wortmannin, a PI-3 kinase inhibitor, repressed this effect in our model. We examined whether pretreatment with GSK-3beta inhibitor lithium or SB216763, mimicked IP-mediated angiogenesis and cardioprotection. Lithium- or SB216763- treated rats revealed accumulation of cytosolic and nuclear beta-catenin. This was followed by increased TCF/LEF transcriptional activity and the upregulation of VEGF, Bcl-2 and survivin mRNA expression accompanied by reduction of apoptotic cardiomyocytes and endothelial cells and increased capillary density after MI. The results of this study demonstrate, first time that inhibition of GSK-3beta followed by accumulation of beta-catenin in the cytosol and nucleus has potent anti-apoptotic and angiogenic effects after MI and that the PI3-kinase/GSK-3beta/beta-catenin signaling pathway plays an important role in IP.
Kaga
Shigeaki
S
Molecular Cardiology Laboratory, Department of Surgery, University of Connecticut Health Center, 263, Farmington Avenue, Farmington, CT 06030-1110, USA.
Zhan
Lijun
L
Altaf
Elham
E
Maulik
Nilanjana
N
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism; D003331:Coronary Vessels / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D007211:Indoles / Q000494:pharmacology; D051034:Inhibitor of Apoptosis Proteins; D019157:Ischemic Preconditioning, Myocardial; D008094:Lithium / Q000494:pharmacology; D051821:Lymphoid Enhancer-Binding Factor 1 / Q000378:metabolism; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009203:Myocardial Infarction / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D018919:Neovascularization, Physiologic; D051058:Oncogene Protein v-akt / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012097:Repressor Proteins; D015398:Signal Transduction; D000077022:Survivin; D051822:T Cell Transcription Factor 1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism*
C117749:Birc5 protein, mouse; D004791:Enzyme Inhibitors; D007211:Indoles; D051034:Inhibitor of Apoptosis Proteins; D051821:Lymphoid Enhancer-Binding Factor 1; D008301:Maleimides; D008869:Microtubule-Associated Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012097:Repressor Proteins; C417521:SB 216763; D000077022:Survivin; D051822:T Cell Transcription Factor 1; D042461:Vascular Endothelial Growth Factor A; D051176:beta Catenin; D008094:Lithium; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; C000605508:Gsk3b protein, rat; D051058:Oncogene Protein v-akt; D038362:Glycogen Synthase Kinase 3