缺血预处理对大鼠视网膜内cPKC亚型特异性膜转位和蛋白表达量的影响  

Effect of ischemic pretreatment on cPKC isoform-specific membrane translocation and protein expression in retina of rats

作　　者：丁宁[1] 王宁利[1] 魏勇[1] 李俊发[2] 

机构地区：[1]首都医科大学北京同仁医院北京同仁眼科中心,北京100730 [2]首都医科大学基础医学院神经生物学系,北京100069

出　　处：《基础医学与临床》2007年第6期616-620,共5页Basic and Clinical Medicine

基　　金：国家自然科学基金(30571991;30672283);北京市自然科学基金(7043067)

摘　　要：目的通过观察缺血预处理(IP)对大鼠视网膜内经典型蛋白激酶C(cPKC)α、βⅠ、βⅡ和γ等4种亚型特异性膜转位(激活)水平和蛋白表达量的影响,确定可能参与视网膜缺血预适应(IPC)形成的cPKC亚型。方法体重200~250g雄性Wistar大鼠随机分为正常对照组(C,n=6),IP组(左眼内压17.29kPa并维持5min,n=48),假手术组(Sham,n=48);后两组分别在手术处理后10、20和40min及1、12、24、72和168h(每个时间点n=6)取视网膜组织。应用Western blot检测cPKC亚型特异性膜转位水平和蛋白表达量。结果大鼠视网膜组织内cPKCα、βⅠ、βⅡ和γ等亚型中,cPKCα膜转位水平在IP处理后10min^168h内与C和Sham组相比无显著改变,而蛋白表达量在IP处理后12~168h明显升高,在72h达高峰。cPKCγ膜转位水平在IP处理后20min^1h内显著增高,在40min达高峰;cPKCγ蛋白表达量在IP处理后12~72h明显增高,在24h达高峰。IP处理对视网膜组织内cPKCβⅠ、βⅡ膜转位水平和蛋白表达量均无显著影响。结论cPKCγ膜转位(激活)增强可能参与大鼠视网膜IPC早期形成,而cPKCα和γ蛋白表达量的增高可能与晚期IPC的维持有关。Objective To identify certain isoforms involved in the onset of retinal ischemic preconditioning （ IPC ）, the effects of ischemic pretreatment （IP） were observed on level of conventional protein kinase C （ cPKC ） α, βⅠ , βⅡ and γisoform-specific membrane translocation and protein expression in retina of rats. Methods Retinal IP was produced by intra-ocular pressure （IOP） elevation for 5 minutes in anesthetized Wistar rats. Sham operation was similar to IP except the pressure elevation. 10, 20, or 40 minutes and 1, 12, 24, 72 or 168 hours after the procedure, cPKC isoform-specific membrane translocation and protein expression were analyzed using Western-blot. Results cPKCα protein expression significantly increased from 12 h to 168 h. A peak reached at 72 h after IP. cPKCγmembrane translocation enhanced during 20 min to 1 hours with a peak at 40 min. cPKCγ protein expression levels significantly increased from 12 hours to 72 hours. A peak was found at 24 hours after IP. However, there were no significant changes in both membrane transloeation of cPKCα, βⅠ,βⅡHand protein expression of cPKCβⅠ, βⅡ in retina of rats following IP, Conclusion The enhanced cPKCγmembrane transloeation, the increased cPKCα and γprotein expressions might be involved in the onset and sustain of retinal IPC in rats respectively.

关 键 词：视网膜缺血预适应 经典型蛋白激酶C 蛋白表达量 膜转位 

分 类 号：R774.1[医药卫生—眼科]