硫氧还蛋白在糖尿病大鼠视网膜中的动态表达  

Dynamic expression of thioredoxin in retina of diabetic rats

作　　者：赵静如[1] 盖春柳[1] 陈晓隆[1] 

机构地区：[1]中国医科大学附属盛京医院眼科,辽宁省沈阳市110004

出　　处：《眼科新进展》2011年第12期1123-1125,1129,共4页Recent Advances in Ophthalmology

基　　金：辽宁省教育厅高等学校科研项目计划(编号:20060994)~~

摘　　要：目的观察硫氧还蛋白(thioredoxin,Trx)在糖尿病(diabetes mellitus,DM)大鼠视网膜中的表达部位及动态变化规律。方法成年Sprague Dawley(SD)大鼠随机分为2组,糖尿病组(DM组)一次性腹腔注射链脲佐菌素制作大鼠DM模型;对照组(NC组)注射同等剂量的柠檬酸缓冲液。在注射后4周、8周、12周,采用免疫组织化学法检测Trx在各组大鼠视网膜中的定位表达,采用Real-timePCR测定视网膜Trx mRNA表达。结果免疫组织化学结果显示,NC组与DM组大鼠视网膜神经纤维层、神经节细胞层、内核层有Trx阳性表达,表达位于细胞浆。Real-timePCR结果显示正常大鼠视网膜有Trx mRNA的表达;与NC组相比,DM组各时间点Trx mRNA表达下降,4周时DM组Trx mRNA相对表达量为0.42±0.03,约为NC组(1.00±0.03)的0.42倍;8周时DM组Trx mRNA相对表达量为0.57±0.04,约为NC组(1.00±0.03)的0.57倍;12周时DM组Trx mRNA相对表达量为0.82±0.08,约为NC组(1.00±0.07)的0.82倍,差异均有统计学意义(均为P<0.05)。DM组视网膜组织TrxmR-NA在4～12周表达逐渐升高,至第12周时仍未达到正常水平,第4周与第12周相比差异有统计学意义(P=0.00)。结论在糖尿病视网膜病变时,Trx mRNA表达下降,说明氧化应激反应产生过多的活性氧使得Trx mRNA表达量下降。随着DM病程的延长,视网膜Trx mRNA表达量逐渐升高,这可能是Trx系统功能下降、自由基增多引起的一种代偿性反应。Objective To observe the position and dynamic changes of thioredoxin（Trx） in the retina of diabetic rats.Methods Adult Sprague Dawley rats were randomly divided into two groups：normal control（NC） group and diabetes mellitus（DM） group.Rats in DM group were injected streptozocin.Rats in NC group were injected equal amount of citric acid buffer.Immunohistochemistry was used to observe the protein expression of Trx at 4 weeks,8 weeks and 12 weeks after injection.The mRNA levels of Trx were determined by real-time PCR.Results Immunohistochemistry was showed that the expression of Trx was in the nerve fiber layer,retinal ganglial cell layer and inner nuclear layer both in NC group and DM group.The results of real-time PCR showed that Trx mRNA was expressed in the retina of normal rats.Compared with those in NC group,the mRNA levels of Trx in DM group decreased.The mRNA relative level of Trx in DM group was 0.42±0.03 at 4 weeks,which was about 0.42 times to that（1.00±0.03） of NC group;The mRNA relative level of Trx in DM group was 0.57±0.04 at 8 weeks,which was about 0.57 times to that（1.00±0.03） of NC group;The mRNA relative level of Trx in DM group was 0.82±0.08 at 12 weeks,which was about 0.82 times to that（1.00±0.07） of NC group,there were statistical differences（all P0.05）.The mRNA levels of Trx in DM group increased from 4 weeks to 12 weeks.But at week 12,the mRNA level of Trx did not reach the normal level.There were significant differences between the DM group at 4 weeks and at 12 weeks（P=0.00）.Conclusions The expression of Trx mRNA decreases in diabetic retinopathy.It is caused by the excessive ROS which are generated by oxidative stress.With the development of diabetes,the expression of Trx mRNA gradually increases in the retina.That may be a compensatory response to the decreasing of Trx system functions and increasing of free radicals.

关 键 词：糖尿病视网膜病变 硫氧还蛋白 氧化应激 

分 类 号：R774.1[医药卫生—眼科]