泛素蛋白酶系统在四氧嘧啶诱导的糖尿病大鼠视网膜中的表达

目的:建立泛素蛋白酶系统(UPS)在正常和8周糖尿病大鼠视网膜的表达图谱,探讨其在糖尿病视网膜病变(DR)发生发展中可能的分子机制。方法:在限制片段差异显示PCR(RFDD-PCR)技术建立正常和8周糖尿病大鼠视网膜基因表达谱的基础上,对差异片段进行生物信息学分析,筛选UPS DR相关基因,并以免疫组织化学、半定量RT-PCR技术进行验证。结果:RFDD-PCR结果显示,泛素蛋白酶系统DR相关基因UBS3A、PSMD8和PSMD11在糖尿病组表达上调。RT-PCR结果显示,糖尿病组UBS3A表达比正常组明显增高,PSMD8和PSMD11则仅在糖尿病组中表达。免疫组织化学结果显示,正常组UBE3A阳性免疫反应物见于内丛状层,外丛状层和锥、杆体细胞层,PSMD8和PSMD11未见阳性细胞;糖尿病组UBE3A、PSMD8和PSMD11阳性细胞明显增多,见于节细胞层、内核层和外核层。结论:UPS与DR发生发展有关。

Expression of ubiquitin-proteasome system in retina of alloxan-induced diabetic rat

Objective:To investigate the expression of ubiquitin-proteasome system(UPS) in the retina of 8-weeks diabetic rats,and explore the potential molecular mechanisms for the role of UPS in diabetic retinopathy(DR).Methods: Using the fragment differential display polymerase chain reaction(RFDD-PCR) technique to build up the retinal gene expression profile of normal and 8-week diabetic rats,to select the candidate genes related to DR by bioinformatic analysis of the differentially expressed gene,which were verified using immunohistochemistry and semi-quantitative RT-PCR.Results: The results of RFDD-PCR revealed the up-regulated expression of UBE3A,PSMD8 and PSMD11 in diabetic rat retina.RT-PCR showed that the expression levels of UBE3A in the diabetic rat retina were obviously higher than that in the normal retina,but the expression of PSMD8 and PSMD11 were just detected in the diabetic rat retina.Immunohistochemistry of the normal rat retina visualized UBE3A-positive immunoreactivity,located in the inner plexiform layer(IPL),outer plexiform layer(OPL),cone and rod cell layer,and no positive immunoreactivity for PSMD8 and PSMD11 were found in any layers.In the diabetic retina,the number of UBE3A,PSMD8 and PSMD11-positive cells was significantly higher compared to the normal rat retina,positive immunoreactivity was found in the ganglion cell layer(GCL),inner nuclear layer(INL) and outer nuclear layer(ONL).Conclusion: The alterations in UPS expression are associated with the developmant and progression of DR.