Ischemia-Induced Apoptosis of Intestinal Epithelial Cells Correlates with Altered Integrin Distribution and Disassembly of F-Actin Triggered by Calcium Overload
Ischemia-Induced Apoptosis of Intestinal Epithelial Cells Correlates with Altered Integrin Distribution and Disassembly of F-Actin Triggered by Calcium Overload
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DOI：
10.1155/2012/617539
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发表时间：
2012-01-01
影响因子：
--
通讯作者：
Qin, Huanlong
中科院分区：
文献类型：
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作者：
Jia, Zhenyi;Chen, Qian;Qin, Huanlong
本研究探讨了肠上皮细胞（IEC）的整合素分布和肌动蛋白细胞骨架的解体，缺血缺氧的反应。进一步研究钙通道阻滞剂（CCB）的保护作用，以探讨细胞损伤的潜在机制。材料和方法。建立大鼠IEC原代培养和体外缺血缺氧模型。在存在和不存在维拉帕米的情况下，将IEC暴露于缺血/缺氧。光镜下观察细胞脱落程度，流式细胞仪检测细胞凋亡率。通过共聚焦显微镜观察细胞内钙离子浓度、整合素分布和F-肌动蛋白形态的变化。结果缺血/缺氧损伤后，IEC的脱落和凋亡增加。维拉帕米治疗可抑制脱落和凋亡。在对照条件下，最强的荧光染色的整合素出现在基底表面的IEC，而这重新分布到顶端膜缺血性损伤。在损伤的细胞中也观察到F-肌动蛋白的解聚。维拉帕米减弱了整合素和F-肌动蛋白的变化。结论.缺血/缺氧损伤下整合素的重新分布和F-肌动蛋白的破坏与IEC脱离和细胞凋亡增加相关。这些事件似乎是由Ca-i（2+）增加触发的，表明CCB在预防和治疗肠损伤中的潜在用途。
The present study examined intestinal epithelial cell (IEC) integrin distribution and disassembly of actin cytoskeleton in response to ischemia-anoxia. Protective effects of calcium channel blocker(CCB) were further examined to explore underlying mechanisms of cellular injury. Materials and Methods. Primary cultures of rat IECs and an in vitro model of ischemia/anoxia were established. IECs were exposed to ischemia/anoxia in the presence and absence of verapamil. The extent of exfoliation was determined using light microscopy while apoptosis rate was measured using flow cytometry. Changes in intracellular calcium, the distribution of integrins and the morphology of F-actin were assessed by confocal microscopy. Results. Detachment and apoptosis of IECs increased following ischemia/anoxia-induced injury. Treatment with verapamil inhibited the detachment and apoptosis. Under control conditions, the strongest fluorescent staining for integrins appeared on the basal surface of IECs while this re-distributed to the apical membrane in response to ischemic injury. Depolymerization of F-actin was also observed in the injured cells. Verapamil attenuated both changes of integrins and F-actin. Conclusions. Redistribution of integrins and disruption of F-actin under ischemia/anoxia injury is associated with IEC detachment and increased apoptosis. These events appeared to be triggered by an increase in Ca-i(2+) suggesting a potential use for CCB in prevention and treatment of intestinal injury.