胞外信号调节激酶通路激活参与视网膜缺血预适应保护作用  

Ischemic preconditioning induces ischemic tolerance against retinal ischemia/reperfusion injury via ERK1/2 pathway

作　　者：丁静文[1] 王宁利[1] 苏吉儿[2] 李俊发[2] 

机构地区：[1]首都医科大学附属北京同仁医院眼科中心,100730 [2]首都医科大学神经生物学系

出　　处：《中华眼科医学杂志（电子版）》2012年第2期15-18,共5页Chinese Journal of Ophthalmologic Medicine(Electronic Edition)

基　　金：北京市教育委员会重点项目(KZ201010025019)

摘　　要：目的探讨胞外信号调节激酶1/2(ERK1/2)信号通路在视网膜缺血预适应形成中的作用机制。方法实验研究。利用升高眼前房灌注压方法建立视网膜缺血模型。成年雄性Wistar大鼠随机分为6组:正常对照组,单纯缺血预处理(IP)组,单纯缺血再灌注损伤(I/R)组,缺血预处理+缺血再灌注损伤(IP+I/R)组,U0126+缺血预处理+缺血再灌注损伤(U+IP+I/R)组,U0126+缺血预处理(U+IP)组。通过Western blot法检测缺血预处理(缺血5 min)后不同时间点ERK1/2磷酸化水平。鼠尾静脉注射U0126选择性抑制ERK1/2通路的激活,观察各实验组7 d后视网膜形态学变化。各处理组与对照组计量资料的比较,采用t检验的方法。以P<0.05为差异有统计学意义。Sigma Plot绘图软件作图。结果 ERK1/2磷酸化水平在缺血预处理后早期20 min至1 h显著升高,40 min时达到高峰(t=18.20,P<0.05;t=17.14,P<0.05)。视网膜厚度测量及神经元细胞计数结果显示,与对照组相比,U+IP+I/R组ONL、INL和IPL厚度均显著降低,神经节细胞层和内核层神经元数目明显减少(t=7.60,P<0.05;t=11.13,P<0.05;t=18.29,P<0.05)。缺血预处理使视网膜对缺血再灌注损伤的耐受性增强,抑制ERK1/2磷酸化可阻断缺血预处理的神经保护作用。结论短暂缺血预处理显著提高视网膜对缺血再灌注损伤的耐受性。早期视网膜ERK1/2通路激活在视网膜缺血预适应神经保护机制中可能具有重要作用。Objective To investigate the role of ERK1/2 pathway in retinal ischemic preconditioning(IPC) of the retina and the molecular mechanism of this Endogenous protection,and provide experimental evidence of new targets in treating ischemic retinal diseases. Methods It was an experimental study. Retinal ischemia was induced in rats by elevating intraocular pressure. Western blotting was used to determine the phosphorylation status of ERK1/2 after retinal IPC. Recovery from ischemia performed 24 h after IPC was assessed histologically at 7 d following ischemia,with or without inhibition of the ERK1/2 pathway. U0126 was administrated intravenously to inhibit the activation of ERK1/2 pathway. Retinal layer thickness and neuron counts were employed to assess the histologic damage. T test was applied for statistical analysis. Difference was statistically significant when P < 0. 05. Pictures were drawn by Sigma Plot software.Results The phosphorylation levels of ERK1/2 were remarkably elevated 20 min-1 h following ischemic pretreatment with 40 min up to the peak(t = 18. 20,P < 0. 05; t = 17. 14,P < 0. 05). Less histologic damage was noted in IP + I/R group. Inhibition of ERK1/2 phosphorylation completely attenuated the protective effect of ischemic pretreatment(t = 7. 60,P < 0. 05; t = 11. 13,P < 0. 05; t = 18. 29,P < 0. 05). Conclusion This study indicates that activation of the ERK1/2 pathway contributes to the protective effects of retinal IPC.

关 键 词：缺血预适应 缺血再灌注损伤 ERK1/2通路 视网膜 

分 类 号：R774.1[医药卫生—眼科]