血管生成素-1对糖尿病大鼠视网膜微血管病变、基质金属蛋白酶和血管内皮生长因子的抑制作用

Inhibitive effects of angiogenin-1 on retinal capillaries lesion,matrix metalloproteinase and vascular endothelial growth factor of diabetes rats

目的观察血管生成素-1(angiogenin-1,Ang-1)对糖尿病大鼠视网膜微血管病变氉和基质金属蛋白酶(matrix metalloproteinases,MMP)、血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的抑制作用。方法通过尾静脉注射链脲佐茵素(streptozotocin,STZ)建立糖尿病大鼠模型。随机分配治疗组大鼠20只,每15d每眼球后注射Ang-1溶液0.05mL1次(4ng·L-1),糖尿病阳性对照组20只不给予任何处理。2组与正常对照组(20只)分别饲养3个月、6个月时,采用眼底荧光素血管造影(fundus fluorescoin angiography,FFA)观察视网膜血管改变;免疫组化法定量检测各组大鼠视网膜VEGF的表达;蛋白印迹法定量检测MMP的表达量。结果 FFA观察结果:3个月时糖尿病阳性对照组大鼠视网膜毛细血管扭曲、不规则,Ang-1治疗组可见明显的改善;6个月时,糖尿病阳性对照组可见视网膜微动脉瘤,Ang-1治疗组与糖尿病阳性对照组相比微动脉瘤减少。免疫组化检测结果显示,3个月、6个月时正常对照组仅见微弱的VEGF表达,灰度值分别为92.9687±2.0400和81.0311±2.7700,糖尿病阳性对照组表达明显上调,灰度值分别为120.0008±2.9011和124.7905±1.9615,与正常对照组比较差异均具有显著统计学意义(P<0.05、P<0.01);Ang-1治疗组3个月、6个月时VEGF表达灰度值分别为116.1548±1.3431和92.8509±2.3234,与糖尿病阳性对照组相比差异有统计学意义(P<0.05)。蛋白印迹法定量检测结果显示,正常对照组MMP蛋白无表达,3个月时Ang-1治疗组表达量高于糖尿病阳性对照组(P<0.05),6个月时糖尿病阳性对照组与Ang-1治疗组间差异无统计学意义(P>0.05)。结论 Ang-1能有效改善糖尿病大鼠视网膜的微血管病变,并抑制视网膜内VEGF、MMP的表达。

Objective To observe the inhibitive effects of angiogenin-1 （Ang-1） on retinal capillary lesion,matrix metalloproteinase （MMP） and vascular endothelial growth factor（VEGF） expression of diabetes rats.Methods Diabetes rat models were established by injection of streptozocin （STZ） through caudal vein and randomly divided into therapy group （20 rats）,each postoculus was injected with Ang-1 solution（4 ng·L-1）of 0.05 mL,and diabetes model group （20 rats,no any treatment was given）.The two groups and normal control group （20 rats） were fed for 3 months and 6 months.Fluorescein fundus angiography （FFA） was adopted to observe the retinal vascular changes,the quantity of VEGF expression in retina of each group was assayed by immunohistochemistry,and the quantity of MMP expression was assayed by Western-blotting.Results FFA showed the retinal capillaries at postoperative 3 months in diabetes model group became distorted and irregular,and those in the therapy group were apparently improved;At postoperative 6 months,the retinal arteriole tumor was visible in the diabetes group,the retinal arteriole tumor was decreased in the therapy group compared with that in the diabetes group.The results of immunohistochemistry showed the mere weak VEGF expression at postoperative 3 months and 6 months in normal control group,which were 120.000 8±2.901 1 and 124.790 5±1.961 5,obvious up-regulation of expression in the diabetes model group,which were 92.968 7±2.040 0 and 81.031 1±2.770 0,there were significant differences compared with normal control group（P0.05,P0.01）,and the therapy group had down-regulation of expression（P0.05）.The results of Western-blotting showed that there was no expression of MMP protein in normal control group,and the expression in therapy group was higher than that in diabetes model group（P0.01）,and there was no statistical difference between diabetes models group and therapy group（P0.05）.Conclusion Ang-1 can effectively improve the retinal capillary lesions of diabetes rats,inhibit VEGF and MMP expressions in the retina.