STZ诱导的糖尿病大鼠晶状体中解耦联蛋白、MnSOD表达的变化

目的研究大鼠晶状体中解耦联蛋白(UCPs)异构体的表达类型,及UCPs、MnSOD mRNA表达随糖尿病病程的变化,探讨糖尿病白内障发病的相关机制。方法以链脲佐菌素(STZ)尾静脉注射建立糖尿病大鼠模型,在模型建立后2、4、8及12周分别摘出大鼠的晶状体,RT-PCR法检测UCP1-55种异构体以及MnSOD的mRNA表达量。结果在正常大鼠晶状体中只表达UCP2。糖尿病模型建立12周时有8/15只(53.3%)大鼠发生糖尿病白内障,16周时有7/9只(77.8%)大鼠发生糖尿病白内障。UCP2、MnSOD mRNA表达随病程而变化,2周时表达量升高,之后二者表达均下降,至12周时降至正常水平。结论大鼠晶状体表达UCP2异构体,UCP2及MnSOD mRNA表达量的逐渐减少与糖尿病白内障的发病有关。

Expression of UCPs,MnSOD in lens of diabetic rats induced by streptozotocin

Objective Oxidative stress and depression of anti-oxidative mechanism play a key role in the formation of diabetic cataract.Uncoupling proteins homologues(UCPs) and MnSOD are two important protective factors during oxidative stress.The study on expression of UCPs mRNA in lens of rats and changes of mRNA expression of UCPs and MnSOD in different courses of diabetes was performed in the purpose of exploring molecular mechanism of diabetic cataract.Methods Sprague-Dawley rats were used in the experiment.Diabetic rats model were established by injection of streptozotocin into the tail vein.Rats were humanely sacrificed 2,4,8 and 12 weeks after the onset of diabetes;the expression of one-five types of UCPs and MnSOD were analyzed in lens of control rats and diabetic rats by RT-PCR.Results Uncoupling protein 2 was detected in lens of normal rats,and its content was similar to that of cerebral cortex and less than that of skeletal muscle.UCP1,3,4,5 mRNA were not detected in normal rat lens with RT-PCR.There was no significant difference in the expression of MnSOD mRNA in lens,cerebral cortex and skeletal muscle.Eight rats(53.3%)exhibited cataract 12 weeks after the onset of diabetes.At 16 weeks after the onset of diabetes,7 rats of 9 rats(77.8%)showed cataract formation.UCP2 mRNA and MnSOD mRNA expressions varied with the courses of disease.UCP2 mRNA and MnSOD mRNA increased at 2 weeks after the onset of diabetes.Then the expression level of UCP2 mRNA and MnSOD mRNA decreased gradually and returned normal level at 12 weeks after the onset of diabetes.Conclusion Diabetes model induced by STZ is available in the study of diabetic cataract.UCP2 is expressed in lens of rats.The mRNA expressions of UCP2 and MnSOD show dynamic changes with development of diabetes.