miR-140-5p抑制VEGF表达对糖尿病大鼠视网膜病变的保护作用

Protective effect of miR-140-5p on diabetic retinopathy rats by inhibiting vasculaRendothelial growth factor

目的探讨miR-140-5p靶向血管内皮生长因子(VEGF)对大鼠糖尿病视网膜病变(DR)的保护作用。方法40只大鼠随机分为5组:对照组、糖尿病组、miR-140-5p组、miRNA NC组和糖尿病+miR-140-5p组,每组8只。糖尿病组和糖尿病+miR-140-5p组大鼠给予腹腔注射链脲佐菌素(65 mg/kg)诱发糖尿病。造模后,miR-140-5p组和糖尿病+miR-140-5p组经尾静脉注射miR-140-5p,miRNA NC组经尾静脉注射miRNA NC,对照组和糖尿病组注射等量0.9%氯化钠溶液,持续给药7 d后,再正常饲养8周。隔周检测5组大鼠体重和血糖。HE染色检测大鼠视网膜病理变化。免疫组化法、RT-PCR法和蛋白印迹法测定大鼠视网膜VEGF的表达。结果与对照组比较,糖尿病组大鼠血糖水平均显著升高(P<0.01),体重显著降低(P<0.01),大鼠视网膜组织和微血管结构破坏,VEGF的mRNA及蛋白表达量显著升高(P<0.01)。糖尿病+miR-140-5p组与糖尿病组相比,血糖降低,体重下降减少,VEGF的表达减少(P<0.01),部分逆转大鼠视网膜组织和微血管结构破坏。结论miR-140-5p抑制糖尿病视网膜病变,其机制可能与miR-140-5p抑制VEGF表达有关。

Objective To investigate the protective effect of miR-140-5p on diabetic retinopathy(DR) by targeting vascular endothelial growth factor(VEGF).Methods Totally 40 rats were randomly assigned into control group, diabetes group, miR-140-5p group, miRNA-NC group, diabetes + miR-140-5p group, with 8 rats in each group. Rats in diabetes group and diabetes + miR-140-5p group were injected intraperitoneally with streptozotocin of 65mg/kg to establish a diabetic model. After modeling, miR-140-5p group and diabetes + miR-140-5p group were injected miR-140-5p Via Tail-Vein Injection, miRNA-NC-group was injected miRNA-NC Via Tail-Vein Injection. Control group and diabetes group were injected the same amount of 0.9% NaCl. After administration duration 7 days, the rats were reared for 8 weeks. The blood glucose and body weight of rats in each group were measured once every 2 weeks. The pathological changes of rat retina were detected by hematoxylin-eosin(H&E) stain. The expression of VEGF in rat retina was determined by immunohistochemistry(IHC), reverse transcription-polymerase chain reaction(RT-PCR) and Western blot.Results Compared with the control group, blood glucose level increased significantly(P<0.01), while body weight was significantly decreased in diabetes group(P<0.01);retinal tissue and the microvascular structure was destroyed, VEGF mRNA and protein expression increased significantly in diabetes group(P<0.01). Compared with the diabetes group, decreased blood glucose, increased body weight and decreased VEGF expression were detected in the diabetes + miR-140-5p group(P<0.01), partially reversed the destruction of retinal tissue and microvascular structure.Conclusion miR-140-5p alleviates DR, which may be related to the inhibition of VEGF expression.