中药菩人丹对OLETF大鼠视网膜葡萄糖调节蛋白78和C/EBP同源蛋白表达的干预作用

Discussion on the intervention effect of traditional Chinese medicine compound Purendan( PRD) on OLETF rats retinal glucose regulated protein factor 78 and C/EBP homologous protein expression

目的探讨中药复方菩人丹(PRD)对OLETF大鼠视网膜葡萄糖调节蛋白78(GRP78)和C/EBP同源蛋白(CHOP)表达的干预作用。方法以雄性自发性2型糖尿病大鼠模型OLETF大鼠和非糖尿病对照组LETO大鼠为实验对象,以血糖峰值>16.7 mmol·L^(-1)和负荷后120 min血糖>11.1 mmol·L^(-1)为2型糖尿病成模标准,将24只成模的OLETF大鼠随机分为PRD治疗组、糖尿病模型组,每组均为12只,同周龄12只雄性LETO大鼠为正常对照组。成功建立模型后,PRD治疗组大鼠连续灌胃PRD(1.8g·kg^(-1)·d^(-1))2个月。Td T介导的d UTP缺口末端标记法(TUNEL)检测OLETF大鼠视网膜神经细胞的凋亡情况;SP免疫组织化学染色法和免疫印迹法检测OLETF大鼠视网膜GRP78和CHOP蛋白的表达。结果糖尿病模型组大鼠视网膜神经细胞凋亡指数、GRP78、CHOP蛋白的表达明显高于正常对照组大鼠(P<0.01)。PRD治疗组大鼠视网膜神经细胞凋亡指数、GRP78、CHOP蛋白的表达明显低于模型组大鼠(P<0.01)。结论 PRD可减少糖尿病大鼠视网膜神经细胞的凋亡,从而起到保护糖尿病视网膜神经组织的作用,这可能与下调GRP78和CHOP的表达,抑制内质网应激有关。

Objective To study the intervention effect of traditional Chinese medicine compound Purendan（ PRD） on OLETF rats retinal glucose regulated protein factor78（ GRP78） and C / EBP homologous protein（ CHOP） expression. Methods Experimental subjects are male OLETF rats which are the spontaneous type 2 diabetic rats model and its homologues in non-diabetic control LETO rats. We let the rats which meet the diabetic standard that the peak glucose is higher than 16. 7 mmol L^-1 or 120 min after glucose load is higher than 11. 1 mmol L^-1 as the model,choose 24 of them,and randomly divided into PRD treatment group,diabetic model group. each group had 12 rats,with 12 of the same age male LETO rats as normal control group. After the model was successfully established,the PRD treatment group rats continuous intragastric administrate PRD（ 1. 8g·kg^-1·d^-1） 2 months.Td T-mediated d UTP nick end labeling（ TUNEL） to detect the apoptosis of retinal nerve cells of OLETF rats. Immunohistochemical staining and Western blotting were used to assess the expression of GRP78 and CHOP protein in OLETF rats＇ retina. Results-Diabetic model group rats retinal neural cell apoptosis index and the expression of GRP78,CHOP protein were significantly higher than that in normal control rats（ P〈0. 01）. PRD treatment group rats retinal neural cell apoptosis index and the expression of GRP78,CHOP protein were significantly lower than that in diabetic model group rats（ P〈0. 01）. Conclusion PRD can inhibit the activation of the apoptosis pathway of endoplasmic reticulum stress by the down regulation of expression of apoptosis gene GRP78,CHOP,thus reduce the apoptosis of nerve cells in the retina of diabetic rats,and play a protective effect on diabetic retinal injury.