泛素-蛋白酶体通路在实验性视网膜脱离后早期对视网膜细胞凋亡的调控作用

Role of ubiquitin-proteasome pathway in regulation of retinal cell apoptosis early after experimental retinal detachment

目的探讨泛素-蛋白酶体通路(UPP)在实验性视网膜脱离(RD)中对视网膜细胞凋亡的调控作用。方法 Wistar大鼠分为正常对照组(n=12)、RD实验组(n=15)和抑制实验组(n=15)。RD实验组和抑制实验组大鼠分别经左眼视网膜下注射透明质酸钠建立RD模型,其中抑制实验组大鼠建模后经腹腔注射蛋白酶体抑制剂MG132(0.10 mg.kg-1.d-1)。建模后4 d,TUNEL染色激光共聚焦显微镜观察凋亡细胞;采用RT-PCR技术和Western blotting方法检测视网膜组织中UPP的标志物视网膜细胞泛素(Ub)、泛素羧基末端水解酶L1(UCH-L1)的mRNA和蛋白表达。结果激光共聚焦显微镜观察发现,与RD实验组比较,抑制实验组凋亡细胞明显增多。Ub、UCH-L1 mRNA和蛋白表达检测结果显示:RD实验组>正常对照组>抑制实验组,组间比较差异均有统计学意义(P<0.05)。结论 RD后早期UPP活性增高,在视网膜细胞凋亡发生中具有保护性调控作用。

Objective To investigate the role of ubiquitin-proteasome pathway(UPP) in the regulation of retinal cell apoptosis after experimental retinal detachment(RD). Methods Wistar rats were divided into normal control group(n=12),RD experiment group(n=15) and inhibition experiment group(n=15).RD model was established in RD experiment group and inhibition experiment group by injection of hyaluronic acid sodium under retina of left eyes,and MG132(0.10 mg·kg-1·d-1) was intraperitoneally injected in inhibition experiment group after model establishment.Laser confocal microscope was used to observe cell apoptosis with TUNEL staining 4 d after model establishment.The expression of UPP markers of ubiquitin(Ub) and ubiquitin carboxy-terminal hydrolases L1(UCH-L1) mRNA and protein in retinal tissues was detected by RT-PCR and Western blotting respectively. Results It was indicated by laser confocal microscopic observations that the number of apoptotic cells in inhibition experiment group was significantly higher than that in RD experiment group.The expression of Ub and UCH-L1 mRNA and protein in RD experiment group was significantly higher than that in normal control group and inhibition experiment group(P<0.05),and the expression of Ub and UCH-L1 mRNA and protein in normal control group was significantly higher than that in inhibition experiment group(P<0.05).Conclusion The activity of UPP increases early after RD,which plays a protective role in the regulation of apoptosis of retinal cells.