Translational Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Am J Physiol Heart Circ Physiol. 2010 Jan;298(1):H75-91. doi: 10.1152/ajpheart.00515.2009. Epub 2009 Oct 23.
It is proposed that ischemic preconditioning (PC) initiates signaling that converges on mitochondria and results in cardioprotection. The outcome of this signaling on mitochondrial enzyme complexes is yet to be understood. We therefore used proteomic methods to test the hypothesis that PC and pharmacological preconditioning similarly alter mitochondrial signaling complexes. Langendorff-perfused murine hearts were treated with the specific GSK-3 inhibitor AR-A014418 (GSK Inhib VIII) for 10 min or subjected to four cycles of 5-min ischemia-reperfusion (PC) before 20-min global ischemia and 120-min reperfusion. PC and GSK Inhib VIII both improved recovery of postischemic left ventricular developed pressure, decreased infarct size, and reduced lactate production during ischemia compared with their time-matched controls. We used proteomics to examine mitochondrial protein levels/posttranslational modifications that were common between PC and GSK Inhib VIII. Levels of cytochrome-c oxidase subunits Va and VIb, ATP synthase-coupling factor 6, and cytochrome b-c1 complex subunit 6 were increased while cytochrome c was decreased with PC and GSK Inhib VIII. Furthermore, the amount of cytochrome-c oxidase subunit VIb was found to be increased in PC and GSK Inhib VIII mitochondrial supercomplexes, which are comprised of complexes I, III, and IV. This result would suggest that changes in complex subunits associated with cardioprotection may affect supercomplex composition. Thus the ability of PC and GSK inhibition to alter the expression levels of electron transport complexes will have important implications for mitochondrial function.
有人提出，缺血预处理（PC）启动了汇集到线粒体的信号转导，从而导致心肌保护。这种信号转导对线粒体酶复合物的影响尚不清楚。因此，我们使用蛋白质组学方法来检验以下假设：PC 和药物预处理同样改变线粒体信号转导复合物。Langendorff 灌注的鼠心用特定的 GSK-3 抑制剂 AR-A014418（GSK 抑制剂 VIII）处理 10 分钟，或进行 4 个 5 分钟的缺血-再灌注循环（PC），然后进行 20 分钟的整体缺血和 120 分钟的再灌注。与时间匹配的对照组相比，PC 和 GSK 抑制剂 VIII 均改善了缺血后左心室发展压的恢复，减少了梗塞面积，并减少了缺血期间的乳酸生成。我们使用蛋白质组学来检查线粒体蛋白水平/翻译后修饰，这些修饰在 PC 和 GSK 抑制剂 VIII 之间是共同的。细胞色素-c 氧化酶亚基 Va 和 VIb、ATP 合酶偶联因子 6 和细胞色素 b-c1 复合物亚基 6 的水平增加，而细胞色素 c 的水平降低，这与 PC 和 GSK 抑制剂 VIII 有关。此外，在 PC 和 GSK 抑制剂 VIII 线粒体超复合物中发现细胞色素-c 氧化酶亚基 VIb 的量增加，超复合物由复合物 I、III 和 IV 组成。这一结果表明，与心肌保护相关的复合物亚基的变化可能会影响超复合物的组成。因此，PC 和 GSK 抑制改变电子传递复合物表达水平的能力将对线粒体功能具有重要意义。
