菩人丹超微粉对糖尿病大鼠视网膜神经细胞凋亡及相关基因表达的影响

摘要

AIM: To investigate the effects of Purendan superfine powder ( PRD ) on apoptosis of retinal neurons and expression of apoptosis - associated genes in diabetic rats.METHODS: Thirty - six male Wistar rats were randomly divided into 3 groups ( n = 12 ): normal control group, diabetes model group and PRD treatment group.The rat model of diabetes was made by continuous intraperitoneal injection of streptozotocin ( STZ ).After successfully established the diabetes animal model, the rats in PRD treatment group were lavaged with PRD for 3 months.Neuronal apoptosis in retina was detected by TdT - mediated dUTP nick end labeling ( TUNEL ).Immunohistochemical staining was used to assess Bcl - 2, Bax and caspase - 3 protein expression in retina.Reverse transcription - polymerase chain reaction ( RT - PCR ) was used to assess the mRNA expression of Bcl - 2, bax and caspase - 3 in retina.RESULTS: Apoptotic index of retina, the protein and mRNA expression of Bax and caspase - 3 in retina were obviously higher in diabetic rats than those in normal control rats ( P ＜ 0.01 ).The mRNA and protein expression of Bcl - 2, the ratio of Bcl - 2/Bax were significantly lower in diabetic rats than those in normal control rats ( P ＜0.01 ).Apoptosis index of retina, the mRNA and protein expressions of bax and caspase - 3 in retina were significantly lower in PRD treatment group than those in diabeic rats ( P ＜ 0.01 ).The mRNA and protein expression of Bcl - 2, the ratio of Bcl - 2/Bax were obviously higher in PRD treatment group than those in diabetic rats ( P ＜0.01 ).CONCLUSION: PRD inhibits neuronal apoptosis by up - regulating Bcl - 2 expression and down - regulating Bax and caspase - 3 expression in retina of diabetic rats, then has protective effects on diabetic retinopathy.%目的:探讨菩人丹超微粉(PRD)对糖尿病大鼠视网膜神经细胞凋亡及相关基因表达的影响.方法:36只Wistar大鼠随机分为3组,正常对照组、糖尿病模型组和PRD治疗组,每组12只.糖尿病模型组和PRD治疗组大鼠均采用链脲佐菌素连续腹腔注射建立2型糖尿病大鼠模型.模型成功建立后,PRD治疗组大鼠给予PRD灌胃3个月.采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)检测大鼠视网膜神经细胞的凋亡;SP免疫组织化学染色法检测视网膜B细胞白血病/淋巴瘤相关抗原2(Bcl-2)、B细胞白血病/淋巴瘤相关抗原相关X蛋白(bax)和半胱氨酸天冬氨酸蛋白酶3(caspase-3)蛋白的表达;逆转录聚合酶链反应(RT-PCR)检测bcl-2、bax和caspase-3 mRNA的表达.结果:糖尿病模型组与正常对照组比较,大鼠视网膜神经细胞凋亡指数、Bax、caspase-3蛋白及mRNA的表达均明显升高(P＜0.01),Bcl-2蛋白及mRNA的表达、Bcl-2/Bax比值显著降低(P＜0.01);PRD治疗组与模型组比较,大鼠视网膜神经细胞凋亡指数、bax、caspase-3蛋白及mRNA的表达均明显降低,Bcl-2 蛋白及mRNA的表达、Bcl-2/Bax比值显著升高(P＜0.01).结论:PRD可通过上调Bcl-2的表达及下调Bax及caspase-3的表达,抑制糖尿病大鼠视网膜神经细胞的凋亡,发挥对糖尿病视网膜的保护作用.