Ulinastatin protects cardiomyocytes against ischemia-reperfusion injury by regulating autophagy through mTOR activation
Ulinastatin protects cardiomyocytes against ischemia-reperfusion injury by regulating autophagy through mTOR activation
复制标题
乌司他丁通过 mTOR 激活调节自噬，保护心肌细胞免受缺血再灌注损伤
DOI：
10.3892/mmr.2014.2450
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发表时间：
2014-10-01
影响因子：
3.4
通讯作者：
Wang, Zhinong
中科院分区：
文献类型：
--
作者：
Xiao, Jian;Zhu, Xiaoyan;Wang, Zhinong
自噬在心肌缺血再灌注（IR）损伤中具有重要意义。乌司他丁已被证明可以通过诱导抗炎作用来保护心肌细胞免受 IR 的侵害。然而，乌司他丁是否具有抗自噬作用尚待阐明。本研究旨在探讨乌司他丁对IR损伤过程中自噬调节的影响。将新生大鼠心肌细胞随机分为对照组、缺氧复氧（HR）组和乌司他丁组。为了研究哺乳动物雷帕霉素靶点 (mTOR) 是否参与介导乌司他丁的保护作用，在乌司他丁处理前 30 分钟用 mTOR 抑制剂雷帕霉素处理细胞。为了证明乌司他丁在体内的抗自噬作用，建立了大鼠IR模型。在通过腹膜注射诱导IR之前30分钟施用乌司他丁（1x10(4) U/kg体重）。使用蛋白质印迹分析评估轻链 3 (LC3)、磷酸化 (p)-mTOR、p-蛋白激酶 B (Akt) 和 p-P70S6 激酶 (p-P70S6K) 蛋白表达。此外，还测量了细胞活力、心肌梗塞面积和乳酸脱氢酶（LDH）水平。发现乌司他丁下调了 LC3-II 蛋白表达，而观察到 p-Akt、p-mTOR 和 p-P70S6K 蛋白表达上调。此外，与体外HR组相比，乌司他丁组的细胞活力增加，LDH减少。此外，发现雷帕霉素可以减弱乌司他丁诱导的心肌保护作用。在体内，乌司他丁被发现可下调 LC3-II 蛋白表达，并减少心肌梗塞面积和 LDH 血清水平。这些发现表明，乌司他丁通过 mTOR 激活调节自噬，对 IR 损伤具有心肌保护作用。
Autophagy is significant in myocardial ischemia-reperfusion (IR) injury. Ulinastatin has been demonstrated to protect cardiomyocytes against IR through inducing anti-inflammatory effects. However, whether ulinastatin has an anti-autophagic effect is yet to be elucidated. The present study aimed to investigate the effect of ulinastatin on the regulation of autophagy during IR injury. Cardiomyocytes of neonatal rats were randomly divided into control, hypoxia-reoxygenation (HR) and ulinastatin groups. In order to investigate whether mammalian target of rapamycin (mTOR) is involved in mediating the protective effect of ulinastatin, cells were treated with the mTOR inhibitor, rapamycin 30 min prior to ulinastatin treatment. To demonstrate the anti-autophagic effect of ulinastatin in vivo, a rat IR model was established. Ulinastatin (1x10(4) U/kg body weight) was administered 30 min prior to the induction of IR via peritoneal injection. Light chain 3 (LC3), phosphorylated (p)-mTOR, p-protein kinase B (Akt) and p-P70S6 kinase (p-P70S6K) protein expression were assessed using western blot analysis. In addition, cell vitality, myocardial infarct size and lactate dehydrogenase (LDH) levels were measured. LC3-II protein expression was found to be downregulated, while p-Akt, p-mTOR and p-P70S6K protein expression were observed to be upregulated by ulinastatin. In addition, cell vitality was found to increase and LDH was observed to decrease in the ulinastatin group compared with the HR group in vitro. Furthermore, rapamycin was found to attenuate the myocardial protective effect that is induced by ulinastatin. In vivo, ulinastatin was found to downregulate LC3-II protein expression, and reduce myocardium infarct size and LDH serum levels. These findings indicate that ulinastatin exhibits a myocardial protective effect against IR injury by regulating autophagy through mTOR activation.