黏附分子E选择素在大鼠糖尿病视网膜病变中的表达

Expression of E-selectin of adhesive molecule in retina of rats with diabetic retinopathy

目的研究黏附分子E选择素在早、中、晚期糖尿病视网膜病变(DR)大鼠微血管中的表达。方法雄性SD大鼠90只,随机分为6、9、12个月正常对照组,每组10只大鼠;及链脲佐菌素(STZ)DR大鼠6、9、12个月模型组,每组20只大鼠。STZDR组用STZ按60mg/kg的剂量腹腔一次性注射,制备DR模型。分别按期处死大鼠,取眼球进行视网膜微血管消化铺片,免疫组织化学EnVision方法显示微血管黏附分子E选择素,采用Leica-Q550W图像分析仪定量分析E选择素在大鼠视网膜微血管中含量表达,并同时观察其形态学改变,了解DR病损程度与E选择素表达有无相关性。结果形态改变:DR6个月组内皮细胞增生,周细胞减少。DR9、12个月组毛细血管网排列紊乱,基底膜明显增厚,毛细血管腔内有较多白细胞黏附、聚集,大面积无细胞毛细血管形成和周细胞内皮细胞凋亡。定量分析结果:正常组无E选择素表达,DR各组均有不同程度E选择素表达,DR各组之间差异有统计学意义(P<0.01),其中以DR9、12个月组表达量最高。结论随DR病程延长,视网膜毛细血管E-选择素表达逐渐增高,并与DR微血管的病损程度呈正相关。

Objectives To investigate the expression of E-selectin of adhesive molecule in microvessels in rats＇ retina with diabetic retinopathy （DR） at the early, middle, and late phase. Methods Ninety Sprague Dawley （SD） male rats were randomly divided into normal control group （6, 9, and 12 months subgroups with 10 rats in each subgroup） and streptozotocin （STZ） DR group （6, 9, 12 months subgroups with 20 rats in each subgroup）. The DR model was set up by one-off celiac injection with STZ at a dose of 60 mg/kg. The rats were executed according to the different time points, and the eyeballs were removed and the digested stretched preparations of retinal microvessels were made. E-selectin of adhesive molecule in microvessels was revealed by EnVision immunohistochemical staining, and the expression of E-selectin in retinal microvessels and the morphological changes were analyzed and observed by Leica-Q550W computer image analytical equipment. The rolativity between degree of impairment of DR and expression of E-selectin was detected. Results Morphological changes： hyperplasia of endotheliocytes and decreased pericytes were found in 6 month DR group; irregularly arranged retinal capillary networks, obviously thickened basilar membrane, many aggregation and adhesion of leucocytes to capillary walls, large areas of acellular capillaries, and opoptosis of endotheliocytes and pericytes were found in 9- and 12-month DR group. Results of quantitative analysis： there was no expression of E- selectin in normal control group, while expression of E-selectin with different degree in each DR group was found. There was significance difference among DR subgroups （P〈0.01）, and the highest expression was found in 6- and 12 month DR group. Conclusions The expression of adhesive molecule in microvessels in rats＇ retina increases as the disease course of DR extends, and has positive correlation with the degree of impairment of microvessels in DR.