靶向端粒酶逆转录酶基因siRNA抑制兔早期后发性白内障的实验研究

Experimental study of inhibitory effect of siRNA targeting TERT on early posterior capsule opacification in rabbits

目的观察靶向端粒酶逆转录酶(TERT)基因小干扰RNA(siRNA)对兔眼白内障术后早期晶状体后囊膜混浊的抑制作用。方法选取20只新西兰大白兔(40眼)纳入研究,采用自身对照法,分为2组:右眼为靶向TERT基因siRNA重组腺病毒TERT-siRNA-Adv组(实验组),左眼为阴性对照重组腺病毒Adv组(对照组),每组20眼;均实施超声乳化晶状体吸除术,术后前房内分别注入0.1 mL滴度为10^(9) PFU/mL的TERT-siRNA-Adv和阴性对照腺病毒;术后第1天、1周、2周、4周观察眼压、角膜水肿、前房闪辉及后发性白内障(PCO)分级情况,术后4周对术眼各组织行病理学检查及采用Western印迹法检测后囊膜细胞内α-平滑肌肌动蛋白(α-SMA)表达变化。结果实验组后囊膜混浊较对照组明显减轻(P<0.05);术后早期存在轻度眼压升高以及眼前节炎症反应(角膜水肿、前房闪辉),但于术后1周恢复,2组间差异无统计学意义(P>0.05)。与对照组相比,实验组后囊膜细胞内α-SMA相对表达量明显下降(P<0.05);组织病理学结果显示,实验组后囊膜下少量成纤维细胞增殖,对照组后囊膜下多层成纤维细胞增殖,囊膜结构紊乱;2组角膜、虹膜各层组织细胞排列整齐,结构完整,无明显炎性细胞浸润。结论靶向TERT基因siRNA可有效抑制晶状体上皮细胞增殖以及兔早期PCO的发生,且对眼前段各组织无明显毒性作用。

Objective To evaluate the inhibitory effect of siRNA targeting telomerase reverse transcriptase(TERT)on early posterior capsule opacification in rabbits.Methods Twenty New Zealand rabbits(forty eyes)were divided into two groups:the right eyes were treated with recombinant adenovirus carrying siRNA targeting TERT(TERT-siRNA-Adv,treatment group),while the left eyes were treated with blank recombinant adenovirus(negative control,control group).Phacoemulsification was performed in both eyes of twenty rabbits and 0.1mL TERT-SiRNA-Adv and negative control adenovirus vector at 10^(9) PFU/mL were injected into the anterior chamber after operation respectively.The intraocular pressure,corneal edema,anterior chamber flare and posterlor capsule opacification(PCO)were observed at 1 day,1 week,2 weeks,4 weeks postoperatively.The histopathological examination of intraocular tissue specimens were performed,and the expression ofα-smooth muscle actin(α-SMA)in posterior capsule cells was detected by Western blot at 4 weeks after operation.Results The PCO in the eyes of the treatment group was significantly less than that of the control group at 4 weeks postoperatively(P<0.05).The levels of intraocular pressure and anterior segment inflammation were mildly elevated in the early postoperative period,and returned to normal in most cases at 1 week postoperatively,there was no statistical significance between the two groups(P>0.05).The expression ofα-SMA was significantly downregulated in the treatment group compared with that of the control group.Histopathological results showed that a small number of fibroblasts proliferated on the posterior capsule in the treatment group,while multiple layers of fibroblasts and disordered capsular structure were found on the posterior capsule in the control group;the tissue cells of the cornea and iris in the two groups were neatly arranged and the structure was complete,and there was no obvious inflammatory cell infiltration.Conclusion siRNA targeting TERT gene can effectively inhibit the proliferation of lens epithelial cells(LECs)and the occurrence of early PCO in rabbits without visible cytotoxicity to other tissues of anterior segment.