Department of Physiology, Medical College of China Three Gorges University, 8 Daxue Road, Yichang 443002, China.
Department of Physiology, Medical College of China Three Gorges University, 8 Daxue Road, Yichang 443002, China.
Life Sci. 2019 Sep 1;232:116658. doi: 10.1016/j.lfs.2019.116658. Epub 2019 Jul 13.
To investigate the cardioprotective effects of hypothermic (25 °C) reperfusion on ischemia/reperfusion injury and the role of transient potential channel M8 (TRPM8) in this process.
Western blot and real-time PCR were used to monitor the expression of TRPM8 in myocardium. Myocardial ischemia/reperfusion injury was induced by 30 min of global ischemia followed by 120 min of reperfusion in Langendorff-perfused hearts from Sprague-Dawley rats. The reperfusion was either normothermic (37 °C) or hypothermic (25 °C). Infarct size and left ventricular function were assessed, and lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA) in the coronary effluent were measured spectrophotometrically, and cardiomyocyte apoptosis was detected by TUNEL assay. The expression of TRPM8, Bcl-2, Bax, cleaved capspase-3, RhoA, and ROCK2 was quantified.
TRPM8 protein and mRNA were expressed in rat myocardium. Hypothermic reperfusion decreased the infarct size, LDH activity, MDA content, apoptosis, and expression of Bax, cleaved caspase-3, RhoA, and ROCK2 compared with normothermic reperfusion. These effects were associated with improved recovery of left ventricular contractility, and were reduced by BCTC, a TRPM8 antagonist. Ischemia/reperfusion injury and the increased expression of Bax, caspase-3, RhoA, and ROCK2 induced by normothermic reperfusion were reduced by Icilin, a TRPM8 agonist.
Hypothermic reperfusion at 25 °C has cardioprotective effects against ischemia/reperfusion injury via activation of TRPM8 to inhibit the oxidative stress-related RhoA/ROCK2 signal pathway.
研究低温（25°C）再灌注对缺血/再灌注损伤的心脏保护作用，以及瞬时电位通道 M8（TRPM8）在该过程中的作用。
使用 Western blot 和实时 PCR 监测心肌中 TRPM8 的表达。通过 Langendorff 灌流心脏从 Sprague-Dawley 大鼠中诱导 30 分钟的整体缺血，随后再灌注 120 分钟。再灌注要么是常温（37°C），要么是低温（25°C）。评估梗塞面积和左心室功能，并通过分光光度法测量冠状动脉流出物中的乳酸脱氢酶（LDH）、超氧化物歧化酶（SOD）和丙二醛（MDA），通过 TUNEL 测定法检测心肌细胞凋亡。定量测定 TRPM8、Bcl-2、Bax、裂解的 capspase-3、RhoA 和 ROCK2 的表达。
TRPM8 蛋白和 mRNA 在大鼠心肌中表达。与常温再灌注相比，低温再灌注降低了梗塞面积、LDH 活性、MDA 含量、凋亡以及 Bax、裂解的 caspase-3、RhoA 和 ROCK2 的表达。这些作用与左心室收缩性的恢复有关，并且被 TRPM8 拮抗剂 BCTC 降低。TRPM8 激动剂 Icilin 降低了常温再灌注引起的缺血/再灌注损伤和 Bax、caspase-3、RhoA 和 ROCK2 的表达增加。
25°C 的低温再灌注通过激活 TRPM8 抑制氧化应激相关的 RhoA/ROCK2 信号通路，对缺血/再灌注损伤具有心脏保护作用。
