Ischemic postconditioning influences electron transport chain protein turnover in Langendorff-perfused rat hearts.
Ischemic postconditioning influences electron transport chain protein turnover in Langendorff-perfused rat hearts.
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作者：
Cao S;Liu Y;Wang H;Mao X;Chen J;Liu J;Xia Z;Zhang L;Liu X;Yu T
缺血后处理（Ischemia postconditioning，IPo）是减轻心肌缺血再灌注（ischemia reperfusion，I/R）损伤（myocardial ischemia reperfusion injury，MIRI）的有效方法，但其具体的分子机制尚不完全清楚。Langendorff灌注的离体大鼠心脏进行整体I/R，并在线粒体ATP敏感性钾通道（mitoKATP）阻断剂5-羟基癸酸（5-HD）的存在或不存在下接受IPo。提取心肌线粒体，进行线粒体比较蛋白质组学分析。IPo可明显减轻I/R大鼠心肌缺血后的梗死面积，改善心功能，而5-HD基本上取消了IPo的心肌保护作用。双向聚丙烯酰胺凝胶电泳（2DE）和MALDI-TOF MS的联合应用确定了8个组间差异表达的蛋白质。I/R后心肌琥珀酸脱氢酶（泛醌）黄素蛋白亚单位（SDHA）的表达增加2倍以上，而IPo导致二氢硫辛酰脱氢酶（DLD）、NADH脱氢酶（泛醌）黄素蛋白1和亚型CRA_B（NDUFV 1）的过度表达。阻断mitoKATP后，MICOS复合物亚基Mic 60（IMMT）和Stress-70蛋白（Grp 75）表达增加，而DLDH、ATP酶亚基A（ATPA）和rCG 44606表达减少。其中7个差异蛋白属于电子传递链（ETC）或代谢调节蛋白，其中5个差异蛋白是由I/R心肌线粒体ATP酶（mitoKATP）关闭诱导的。因此，我们得出结论，IPo的心肌保护作用依赖于能量稳态调节。DLD、SDHA、NDUFV 1、Grp 75、ATPA和rCG 44606可能参与IPo的神经保护作用。
Ischemia postconditioning (IPo) is a promising strategy in reducing myocardial ischemia reperfusion (I/R) injury (MIRI), but its specific molecular mechanism is incompletely understood. Langendorff-perfused isolated rat hearts were subjected to global I/R and received IPo in the absence or presence of the mitochondrial ATP-sensitive potassium channel (mitoKATP) blocker 5-hydroxydecanoate (5-HD). Myocardial mitochondria were extracted and mitochondrial comparative proteomics was analyzed. IPo significantly reduces post-ischemic myocardial infarction and improved cardiac function in I/R rat hearts, while 5-HD basically cancelled IPo’s myocardial protective effect. Joint application of two-dimensional polyacrylamide gel electrophoresis (2DE) and MALDI-TOF MS identified eight differentially expressed proteins between groups. Expression of cardiac succinate dehydrogenase (ubiquinone) flavoprotein subunit (SDHA) increased more than two-fold after I/R, while IPo led to overexpression of dihydrolipoyl dehydrogenase (DLD), NADH dehydrogenase (ubiquinone) flavoprotein 1 and isoform CRA_b (NDUFV1). When the mitoKATP was blocked, MICOS complex subunit Mic60 (IMMT) and Stress-70 protein (Grp75) were over expressed, while DLDH, ATPase subunit A (ATPA) and rCG44606 were decreased. Seven of the differential proteins belong to electron transport chain (ETC) or metabolism regulating proteins, and five of them were induced by closing mitoKATP in I/R hearts. We thus conclude that IPo’s myocardial protective effect relies on energy homeostasis regulation. DLD, SDHA, NDUFV1, Grp75, ATPA and rCG44606 may contribute to IPo’s cardial protective effect.