Introduction. Ischemia/Reperfusion (I/R) is a primary cause of myocardial injury after acute myocardial infarction resulting in the release of damage-associated molecular patterns (DAMPs), which can induce a sterile inflammatory response in the myocardial penumbra. Targeted temperature management (TTM) after I/R has been established for neuroprotection, but the cardioprotective effect remains to be elucidated. Therefore, we investigated the effect of TTM on cell viability, immune response, and DAMP release during oxygen-glucose deprivation/reperfusion (OGD/R) in murine primary cardiomyocytes. Methods. Primary cardiomyocytes from P1-3 mice were exposed to 2, 4, or 6 hours OGD (0.2% oxygen in medium without glucose and serum) followed by 6, 12, or 24 hours simulated reperfusion (21% oxygen in complete medium). TTM at 33.5°C was initiated intra-OGD, and a control group was maintained at 37°C normoxia. Necrosis was assessed by lactate dehydrogenase (LDH) release and apoptosis by caspase-3 activation. OGD-induced DAMP secretions were assessed by Western blotting. Inducible nitric oxide synthase (iNOS), cytokines, and antiapoptotic RBM3 and CIRBP gene expressions were measured by quantitative polymerase chain reaction. Results. Increasing duration of OGD resulted in a transition from apoptotic programmed cell death to necrosis, as observed by decreasing caspase-3 cleavage and increasing LDH release. DAMP release and iNOS expression correlated with increasing necrosis and were effectively attenuated by TTM initiated during OGD. Moreover, TTM induced expression of antiapoptotic RBM3 and CIRBP. Conclusion. TTM protects the myocardium by attenuating cardiomyocyte necrosis induced by OGD and caspase-3 activation, possibly via induction of antiapoptotic RBM3 and CIRBP expressions, during reperfusion. OGD induces increased Hsp70 and CIRBP releases, but HMGB-1 is the dominant mediator of inflammation secreted by cardiomyocytes after prolonged exposure. TTM has the potential to attenuate DAMP release.

中文翻译：

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定向温度管理对小鼠原代心肌细胞氧-葡萄糖剥夺/再灌注损伤和DAMP释放的影响

引言。缺血/再灌注（I / R）是急性心肌梗塞后导致心肌损伤的主要原因，导致释放与损伤相关的分子模式（DAMPs），后者可在心肌半影中诱发无菌性炎症反应。为神经保护建立I / R之后的目标温度管理（TTM），但心脏保护作用尚待阐明。因此，我们研究了TTM对鼠原代心肌细胞中氧葡萄糖剥夺/再灌注（OGD / R）过程中细胞活力，免疫反应和DAMP释放的影响。方法。将P1-3小鼠的原代心肌细胞暴露于2、4、6小时的OGD（不含葡萄糖和血清的培养基中，氧气浓度为0.2％），然后进行6、12或24小时的模拟再灌注（完全培养基中的氧气含量为21％）。在33.5°C下开始OTM内的TTM，对照组保持在37°C的常氧下。通过乳酸脱氢酶（LDH）的释放和通过caspase-3激活的凋亡来评估坏死。通过Western印迹评估OGD诱导的DAMP分泌。诱导型一氧化氮合酶（iNOS），细胞因子，抗凋亡RBM3和CIRBP基因表达通过定量聚合酶链反应进行了测量。结果。通过减少caspase-3裂解和增加LDH释放可以观察到，增加OGD的持续时间会导致从程序性细胞死亡到坏死的转变。DAMP释放和iNOS表达与坏死增加相关，并在OGD期间通过TTM有效减弱。此外，TTM诱导抗凋亡RBM3和CIRBP的表达。结论。TTM通过减轻再灌注期间OGD和caspase-3激活诱导的心肌细胞坏死来保护心肌，可能是通过诱导抗凋亡RBM3和CIRBP表达来实现的。OGD诱导Hsp70和CIRBP释放增加，但HMGB-1是长时间暴露后由心肌细胞分泌的炎症的主要介质。TTM具有减弱DAMP释放的潜力。