凋亡相关基因Bcl-2及Bax在糖尿病大鼠早期视网膜病变细胞凋亡中的作用

目的研究凋亡相关基因Bcl- 2,Bax在早期糖尿病大鼠视网膜的表达,探讨其在糖尿病视网膜病变细胞凋亡中的作用.方法选择健康成年 Wistar 大鼠 40只,随机分成正常对照( CON)、糖尿病 1个月(DM1)、 3个月( DM3)及 6个月( DM6)组.腹腔内注射链脲佐菌素( STZ)诱发大鼠糖尿病.制备大鼠视网膜石蜡切片行免疫组化ABC法染色,并对染色结果进行计算机图像分析. 结果于 CON及 DM各组,Bax和 Bcl- 2二基因的蛋白均在视网膜血管表达,且随病程进展,其阳性反应强度逐渐增加.此外,Bcl- 2阳性反应在 DM3组于色素上皮细胞出现,在 DM6组,再进一步扩大到视杆内节和节细胞.而Bax在 DM6亦出现于节细胞. 结论凋亡相关基因 Bcl- 2和 Bax在早期糖尿病大鼠视网膜血管和神经细胞的表达随病程的进展逐渐增强,二者在糖尿病视网膜细胞凋亡中起重要作用.

Expression of apoptosis- related genes Bcl- 2 and Bax in the retinas of early diabetic rats

AIM: To study the expression of apoptosis- related genes (Bcl- 2 and Bax) in the retinas of early diabetic rats, and investigate the roles these genes play in retinal cell apoptosis in diabetic retinopathy. METHODS:Forty healthy adult Wistar rats were randomly divided into normal control groups and diabetes mellitus groups for 1 (DM1), 3 (DM3) and 6 months (DM6). Diabetic models were induced by peritoneal injection with streptozotocin, and the paraffin- embedded retinal sections were stained by immunohistochemical method (ABC) and analyzed by computer- picture image analysis system. RESULTS: In the control and each DM group, both Bcl- 2 and Bax proteins were detected in the retinal vessels. With the progression of diabetes, the intensity of positive reaction increased. Moreover, Bcl- 2- positive reaction was observed in the pigment epithelial cells in DM3 group, and extended further to the inner rod segments and ganglion cells in DM6 group. Bax was expressed mainly in the ganglion cells in DM6 group. CONCLUSION: The expression of Bcl- 2 and Bax in the retinal capillary cells and nerve cells gradually increase in diabetic rats with the progression of diabetes. Bcl- 2 and Bax play an important role in the retinal cell apoptosis of early diabetic retinopathy.