Insulin-induced myocardial protection in isolated ischemic rat hearts requires p38 MAPK phosphorylation of Hsp27

摘要

insulin is more than a hormone regulating glucose metabolism in cells. Insulin binds to receptors and activates several intra-cellular signaling transduction pathways such as phosphatidyl-inositol 3-kinase (PI3K)/protein kinase B (PKB/Akt) pathway, ERK1/2 pathway, and p38 MAPK pathway. Activation and phosphorylation of intermediates within these pathways regulate transcription, translation, and various aspects of glucose metabolism. In addition, insulin is effective at reducing myocardial ischemia-reperfusion injury (32, 42). The cardioprotec-tive effect of insulin may be mediated via PI3K, PKB/Akt, and p70S6 kinase cell signaling (64) or by increasing nitric oxide bioavailability (23, 33). Recently, insulin has been shown to improve the recovery of the contractile function of cardiomy-ocytes after simulated ischemia-reperfusion through an Akt-dependent and sarco(endo)plasmic reticulum Ca2+-ATPase 2a-mediated pathway (74).