Chloride Channel Inhibition Prevents ROSdependentApoptosis Induced by Ischemia-Reperfusion in Mouse Cardiomyocytes
Chloride Channel Inhibition Prevents ROSdependentApoptosis Induced by Ischemia-Reperfusion in Mouse Cardiomyocytes
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DOI：
10.1159/000089840
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发表时间：
2005-11
影响因子：
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通讯作者：
Xiaoming Wang;N. Takahashi;H. Uramoto;Y. Okada
中科院分区：
文献类型：
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作者：
Xiaoming Wang;N. Takahashi;H. Uramoto;Y. Okada
心肌细胞在缺血后的凋亡和心肌细胞在缺血后的凋亡，并已知其诱导机制。最近发现，在线粒体介导的细胞凋亡中，氯离子通道的活性触发了细胞凋亡体积的减少，而活性氧自由基(ROS)则参与了该通道的激活。因此，在本研究中，我们研究了氯离子通道和ROS在原代培养的小鼠心肌细胞缺血再灌注过程中对细胞凋亡的影响。通过caspase-3激活、染色质凝集、DNA梯状条带和细胞存活率下降来衡量细胞的凋亡性，在再灌流后数十小时观察到，但在缺血后即刻观察不到。非选择性氯通道阻滞剂(DIDS或NPPB)在再灌流期间应用时可使细胞免于凋亡死亡，但不能在缺血期应用。另一种对容量敏感的外向整流(VSOR)氯离子通道有相对特异性的阻断剂(根皮素)也能有效地保护缺血心肌细胞免受再灌流诱导的细胞凋亡。心肌细胞内ROS在再灌流期间显著增加，但未见缺血期。ROS、H_2O_2和超氧化物歧化酶的清除剂均能抑制缺血再灌注诱导的细胞凋亡。因此，缺血再灌注诱导心肌细胞凋亡的机制可能与VSORCl-通道活性和细胞内ROS的产生有关。
Apoptosis of cardiomyocytes following ischemia and Apoptosis of cardiomyocytes following ischemia and known about the mechanism by which it is induced. Recently, essential roles of a Cl- channel whose activity triggers the apoptotic volume decrease and of reactive oxygen species (ROS) in activation of this channel have been identified in mitochondrion-mediated apoptosis. Therefore, in this study, involvement of Cl- channels and ROS in apoptosis was studied in primary mouse cardiomyocyte cultures subjected to ischemia-reperfusion. Apoptotic cell death as measured by caspase-3 activation, chromatin condensation, DNA laddering, and cell viability reduction was observed tens of hours after reperfusion but never immediately after ischemia. A non-selective Cl-channel blocker (DIDS or NPPB) rescued cells from apoptotic death when applied during the reperfusion, but not ischemia, period. Another blocker relatively specific to the volume-sensitive outwardly rectifying (VSOR) Cl-channel (phloretin) was also effective in protecting ischemic cardiomyocytes from apoptosis induced by reperfusion. A profound increase in intracellular ROS was detected in cardiomyocytes during the reperfusion, but not ischemia, period. Scavengers for ROS, H2O2 and superoxide all inhibited apoptosis induced by ischemia-reperfusion. Thus, it is concluded that the mechanism by which cardiomyocyte apoptosis is induced by ischemia-reperfusion involves VSOR Cl- channel activity and intracellular ROS production.