白藜芦醇对糖尿病大鼠视网膜Muller细胞凋亡的防护作用及分子机制研究

Protective effects of resveratrol on apoptosis of Muller cells in rats with diabetic retinopathy and its molecular mechanisms

目的视网膜Muller细胞凋亡发生在糖尿病视网膜病变(DR)早期,探讨自藜芦醇在DR早期Muller凋亡中的重要意义。方法 5、10mg·kg-1·d-1白藜芦醇喂养健康和糖尿病大鼠1~7个月后取材,使用TUNEL检测Muller细胞凋亡,免疫荧光检测转录因子特异蛋白1(SP1)细胞定位,qRT-PCR检测miR-29b和SP1基因表达,Western blot检测SP1蛋白表达。结果糖尿病1、3、5和7个月大鼠视网膜中均检测到TUNEL阳性细胞,白藜芦醇干预能有效抑制糖尿病引起的大鼠视网膜内核层(INL)Muller细胞凋亡(P<0.01)。与年龄相匹配的健康对照大鼠相比,糖尿病大鼠视网膜中miR-29b的表达显著降低,SP1表达显著增高(P<0.01),糖尿病引起的miR-29b表达下调和SP1表达上调均能被白藜芦醇干预抑制(P<0.05)。结论白藜芦醇是一个潜在的治疗DR的选择,miR-29b/SP1信号通路在白藜芦醇的抗凋亡机制中起重要作用。

Objective To evaluate the antiapoptosis effects of resveratrol on retinal Muller cells in rats with diabetic retinopathy(DR).Methods Retina was obtained from normal and diabetic rats with resveratrol(5,10 mg·kg^-1·d^-1)treatments for 1-7 months.TdT-mediated dUTP-biotin nick end labeling(TUNEL)was used to detect apoptosis.Immunofluorescence was used to assess the distribution of transcription specificity protein 1(SP1)in retina.MiR-29b and SP1 mRNA expressions was evaluated by quantitative real-time polymerase chain reaction(qRT-PCR).SP1 protein expression was evaluated by Western blot.Results TUNEL-positive cells can be dedected in the inner nuclear layer(INL)retina of 1-,3-,5-,7-month diabetic rats and resveratrol administration effectively suppressed streptozotocin(STZ)-induced apoptosis of Muller cells in INL(P<0.01).As compared with normal rats,miR-29b expression in diabetic rats retina decreased,and the SP1 expression significantly increased(P<0.01).Furthermore,diabetes-induced down-regulated expression of miR-29b and up-regulated expression of SP1 could be rescued by resveratrol(P<0.05).Conclusion Resveratrol is a potential therapeutic option for DR and miR-29b/SP1 pathway play roles in the anti-apoptosis mechanism of resveratrol.