血管生成素-1对糖尿病大鼠视网膜微血管渗漏的保护作用

The Protective Function of Angiogenin-1 on Retina Capillaries Leakage of Diabetes Big Mouse

目的研究血管生成素-1(Ang-1)对糖尿病大鼠早期视网膜微血管渗漏、及血管细胞凋亡的影响,并探讨其作用机制。方法应用链脲佐菌素(STZ)制备SD大鼠糖尿病模型。只随机分为6组:糖尿病3月组(DM3)、6月组(DM6),Ang-1治疗3月组(ANG3)、6月组(ANG6)及正常对照3月组(CON3)、6月组(CON6)。ANG组大鼠每只眼球球后注射Ang-1溶液0.05 mL/15 d(4μg/mL)。各组大鼠到期后,尾静脉注射异硫氰酸葡聚糖,制备视网膜血管铺片;免疫组化法定量检测视网膜VEGF的表达;蛋白印迹法定量检测视网膜Survivin的表达量。所得数据应用SPSS软件包进行统计学分析。结果 DM3组大鼠视网膜毛细血管扭曲、不规则,可见无灌注区,ANG3组可见明显的改善。DM6组毛细血管末端出现了"芽孢"样的增生,ANG6组并未发现。视网膜VEGF的表达量DM组显著增高,与CON组比较差异具有高度显著性(P<0.01),ANG组较DM组表达量有所减少,差异有显著性(P<0.05)。大鼠视网膜Survivin蛋白CON组无表达,ANG3组表达量高于DM3差异有高度显著性(P<0.01),DM6与ANG6组间差异无显著性(P>0.05)。结论 Ang-1抑制糖尿病大鼠视网膜毛细血管的渗漏,并抑制糖尿病大鼠视网膜VEGF表达量的升高;可阻止糖尿病大鼠视网膜毛细血管细胞凋亡。

Objective The paper aims to explore the effect of Ang-1 on retina vascular permeability and endothelial cell apoptosis in vivo and in-vitro environments and to approach the mechanism of action. Methods Animal models were induced by streptozocin （60 mg/kg weight） on Sprague-Dawley rats and randomly divided into DM3, DM6, ANG3, ANG6 group and control group （CON）. ANG group rats were intraocular injected with Ang- 1 0.05mL （ 4 μg/mL） every fifteen days. After 3 to 6 months, every rat was injected with 55 mg Flurorescein isothiocyanate-dextran through caudal vein. The retinal try sin digests were prepared. The quanti- ty of VEGF on the retina was assayed by Immune-histology and the quantity of Surviving was assayed by Western-blotting. Two ani- mals of each group were killed after 3 months and 6 months respectively. The data obtained were by statistically assessed. Results DM3 group showed retinal capillary becoming distortion and irregularity, area of no perfusion while ANG3 group got melioration obvi- ously. DM6 group showed spring proliferation in the end of the capillary, while ANG6 did not show such phenomenon, DM group showed higher quantity of VEGF than CON group （ P〈0. 01 ）, while ANG group showed lower quantity of VEGF than DM group （ P〈 0. 05）. CON group showed negative of Surviving, ANG3 group showed higher quantity of surviving than DM3 group （P〈0. 01 ）, while DM6 group and ANG6 had no significant difference （P〉0. 05 ）. Conclusions Ang-1 can inhibit the diabetic retinal capillary leakage in early diabetes rats and inhibit the high levels of VEGF and the frequency of early apoptosis in retinal capillary cells as well.