Institute for Pathophysiology, West German Heart and Vascular Center, 123109University of Essen Medical School, Essen, Germany.
Heart Center Essen-Huttrop, West German Heart and Vascular Center, 123109University of Essen Medical School, Essen, Germany.
J Cardiovasc Pharmacol Ther. 2022 Jan-Dec;27:10742484221097273. doi: 10.1177/10742484221097273.
Remote ischemic conditioning (RIC) induces the release of circulating cardioprotective factors and attenuates myocardial ischemia/reperfusion injury. Evidence for such humoral cardioprotective factor(s) is derived from transfer with plasma (derivatives) from one individual undergoing RIC to another individual's heart, even across species. With transfer into an isolated perfused heart, only a single plasma (derivative) sample can be studied with infarct size as endpoint, and therefore the comparison of samples before and after RIC or between RIC and placebo is hampered by the inter-individual variation of infarct sizes in isolated perfused hearts. We therefore developed a preparation of cardiomyocytes from a single mouse heart, where aliquots of the same heart can undergo hypoxia/reoxygenation (H/R) with exposure to buffer, RIC, or placebo samples without or with pharmacological blockade. To validate this approach, we used plasma dialysates taken before and after RIC from patients undergoing coronary bypass grafting who had experienced protection by RIC (troponin release ↓ by 28% vs placebo). The cardiomyocyte bioassay had little variation after H/R with buffer (mean ± standard deviation; 7% ± 2% viable cells) and demonstrated preserved viability after RIC (15% ± 5% vs 6% ± 3% before). For comparison, infarct size in isolated mouse hearts after global ischemia and reperfusion was 22% ± 14% of left ventricular mass after versus 42% ± 14% before RIC. Stattic, an inhibitor of signal transducer and activator of transcription (STAT)3 protein, abrogated protection in the cardiomyocytes. We have thus established a cardiomyocyte bioassay to analyze RIC's protection which minimizes inter-individual variation and the use of animals.
远程缺血预处理（RIC）可诱导循环保护因子的释放，减轻心肌缺血/再灌注损伤。这种体液保护因子的证据来自于将接受 RIC 的个体的血浆（衍生物）转移到另一个个体的心脏，甚至跨越物种。在进行离体心脏灌注时，只能使用单一的血浆（衍生物）样本作为终点来研究梗死面积，因此，RIC 前后或 RIC 与安慰剂之间的样本比较受到离体灌注心脏中梗死面积个体间差异的影响。因此，我们开发了一种从单个鼠心制备心肌细胞的方法，其中同一心脏的等分试样可以在暴露于缓冲液、RIC 或安慰剂样品的情况下进行缺氧/复氧（H/R），而无需或进行药理学阻断。为了验证这种方法，我们使用了在接受冠状动脉旁路移植术的患者中接受 RIC 保护的患者（肌钙蛋白释放↓28%与安慰剂相比）之前和之后进行 RIC 时获得的血浆透析液。H/R 后用缓冲液处理的心肌细胞生物测定的变化很小（平均±标准偏差；7%±2%存活细胞），并且在 RIC 后显示出保留的活力（15%±5%与之前的 6%±3%相比）。相比之下，在整体缺血和再灌注后，离体鼠心的梗死面积为左心室质量的 22%±14%，而在 RIC 之前为 42%±14%。STAT3 蛋白信号转导和转录激活因子（STAT）3 的抑制剂 Stattic 使心肌细胞的保护作用丧失。因此，我们已经建立了一种心肌细胞生物测定法来分析 RIC 的保护作用，该方法最大限度地减少了个体间差异和动物的使用。
