[钠/钙交换体通过激活离体大鼠心脏中的钙调蛋白依赖性蛋白激酶II介导缺血-再灌注损伤]

[Na+/Ca2+ exchanger mediates ischemia-reperfusion injury by activation of CaMKII in isolated rat heart].

作者信息

Kong Lingheng, Liang Fei, Chen Yulong, Wei Ming, Sun Na, Zhu Juanxia, Su Xingli

机构信息

Institute of Basic Medical Science, Xi'an Medical University, Xi'an 710021, China.

School of Pharmaceutical Sciences, Xi'an Medical University, Xi'an 710021, China.

出版信息

Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2018 Jan 28;43(1):28-34. doi: 10.11817/j.issn.1672-7347.2018.01.005.

DOI:10.11817/j.issn.1672-7347.2018.01.005

PMID:30154288

Abstract

To investigate the role of Na+/Ca2+ exchanger (NCX) in myocardial ischemia-reperfusion injury and the underlying mechanisms.  Methods: Forty Sprague-Dawley rats were divided into 4 groups randomly: a control group, a KB-R7943 group, an ischemia-reperfusion group (IR group), and an IR plus KB-R7943 group (KB-R7943+IR group). Isolated Sprague Dawley male rat hearts underwent Langendorff perfusion. The ratio of left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), the infarct size of myocardium, and the lactate dehydrogenase (LDH) activity in the coronary flow was determined. HE staining was used to assess the change of myocardial morphology. Western blot was used to determine the levels of cleaved caspase-3, cytochrome c and the phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and the Thr17 site of phospholamban.  Results: Compared with the control group, IR group significantly induced an enlarged infarct size, reduction of the ratio of LVDP, up-regulation of cytochrome c, cleaved caspase-3, p-CaMKII and p-phospholamban, and increased in the activity of LDH, the level of LVEDP (P<0.01) and the disordered myocardial morphology. These effects were significantly attenuated in the presence of KB-R7943 treatment (10 μmol/L).  Conclusion: NCX mediates myocardial ischemia-reperfusion-induced cell apoptosis and necrosis through activation of CaMKII.

摘要

探讨钠/钙交换体（NCX）在心肌缺血再灌注损伤中的作用及其潜在机制。方法：将40只Sprague-Dawley大鼠随机分为4组：对照组、KB-R7943组、缺血再灌注组（IR组）和IR加KB-R7943组（KB-R7943+IR组）。采用Langendorff灌注法对Sprague Dawley雄性大鼠离体心脏进行灌注。测定左心室发展压（LVDP）、左心室舒张末期压（LVEDP）、心肌梗死面积以及冠脉流量中乳酸脱氢酶（LDH）活性的比值。采用苏木精-伊红（HE）染色评估心肌形态学变化。采用蛋白质免疫印迹法（Western blot）检测裂解的半胱天冬酶-3、细胞色素c水平以及钙调蛋白依赖蛋白激酶II（CaMKII）和受磷蛋白Thr17位点的磷酸化水平。结果：与对照组相比，IR组显著诱导梗死面积增大、LVDP比值降低、细胞色素c、裂解的半胱天冬酶-3、p-CaMKII和p-受磷蛋白上调，LDH活性、LVEDP水平升高（P<0.01）以及心肌形态紊乱。在KB-R7943（10 μmol/L）处理后，这些效应显著减弱。结论：NCX通过激活CaMKII介导心肌缺血再灌注诱导的细胞凋亡和坏死。