脑源性神经营养因子对糖尿病大鼠视网膜Müller细胞的保护作用

摘要

目的 探讨脑源性神经营养因子对糖尿病视网膜Mtiller细胞的保护作用.方法 健康雄性SD大鼠54只,腹腔注射链脲佐菌素建立糖尿病模型.随机分为对照组、糖尿病组、脑源性神经营养因子(brain derived neurotrophic factor,BDNF)组.含0.1 g·L-1BSA的PBS平衡盐溶液制备BDNF注射液.BDNF组大鼠于糖尿病模型建成4周后开始注射BDNF注射液,对照组和糖尿病组注射等剂量的PBS平衡盐溶液.8周后,利用免疫荧光及Western blot检测胶质细胞谷氨酸转运体(L-glutamate/L-aspartate transporter,GLAST)、谷氨酰胺合成酶(glutamine synthetase,Gs)及神经元标记物SYN(synaptophysin)的表达量,谷氨酸含量测定试剂盒检测视网膜中谷氨酸的含量.结果 与对照组相比,糖尿病组GLAST、GS、SYN表达显著下降,且视网膜谷氨酸含量均明显升高(均为P＜0.01),而BDNF组差异均无统计学意义(均为P＞0.05);与糖尿病组相比,BDNF组GLAST,GS、SYN表达均升高(均为P＜0.01),谷氨酸含量均显著减少(均为P＜0.01).结论 糖尿病视网膜病变早期给予外源性BDNF可以提高Müller细胞中GLAST、SYN及GS表达活性,改善Müller细胞功能,并且能使视网膜神经节细胞免受损害,提示BDNF对糖尿病视网膜病变条件下视网膜中的Müller细胞具有保护作用.%Objective To investigate the protective effect of brain derived neurotrophic factor (BDNF) on Müller cells in the retina of diabetic rats.Methods A total of 54 healthy male SD rats were recruited and randomly divided into control group,diabetic group and BDNF group.Then a diabetic model was established by intraperitoneal injection of streptozotocin in rats of diabetic and BDNF groups.Preparation of BDNF injection was performed using PBS balanced salt solution containing 0.1 g · L 1 BSA.The BDNF group was given BDNF injection,while the control and diabetic group were injected with equal dose of PBS balanced salt solution 4 weeks after successful modeling.And after 8 weeks,the expression of L-glutamate/L-aspartate transporter (GLAST),glutamine synthetase (GS) and synaptophysin (SYN) were detected by immunofluorescence technique and Western blot,and the content of glutamic acid in retina was determined by glutamic acid determination kit.Results Compared with the control group,the expression of GLAST,GS and SYN were significantly decreased in diabetic group,and the content of glutamic acid was increased significantly (all P ＜ 0.01).Compared with the diabetic group,the expression of GLAST,GS and SYN were increased in BDNF group,and the glutamate level was decreased significantly (all P ＜0.01).Conclusion In the early stage of diabetic retinopathy,administration of exogenous BDNF can unregulated the expression of GLAST,SYN and GS and improve the function of Müller cells to protect RGC against damage,suggesting that BDNF has neuroprotective effects on Müller cells in retina of rats with diabetic retinopathy.