视网膜新生血管形成中Cathepsin B的变化

Expression of Cathepsin B in the development of retinal neovascularization

目的通过观察Cathepsin B的变化,探讨视网膜新生血管的发病机制。方法取C57BL/6J7d龄小鼠30只,随机分为对照组和实验组,实验组在缺氧环境中建立视网膜新生血管动物模型。采用苏木精-伊红染色、视网膜ADP酶染色铺片及免疫组织化学法进行检测,同时测定眼组织Cathepsin B活性。结果组织病理学见突破内膜新生血管内皮细胞核数,无血管区面积及无血管区面积/视网膜面积,实验组与对照组比较差异均有统计学意义(P<0.01);对照组与实验组Cathepsin B平均光密度、Cathepsin B活性比较差异有统计学意义(P<0.01)。结论C57BL/6J构建小鼠视网膜新生血管动物模型后,小鼠视网膜组织Cathepsin B表达增加、活性增强,CathepsinB可能是视网膜新生血管产生的一个重要因素。

Objective Retinal neovascularization is a kind of disease which affected human vision severely, and its pathogenesis is not clear. Present article was to discuss the change of Cathepsin B in the development of retinal neovascularizaton. Methods Thirty 7-day-old C57BL/6J mice were assigned to control group and experiment group randomly. Fifteen mice in experiment group were exposed to 75% oxygen for 5 days and then to room air for another 5 days. Fifteen mice in control group were exposed to room air for 10 days. Retinal neovascularization was tested by the vascular pattern in adenosine diphosphate-ase （ADPase） stained retina flat-mounts and counting the number of new vascular cell nuclei extending into the internal limiting membrane in cross-sections. The mean optical density of Cathepsin B of retina was measured by immunohistochemistry. The Cathepsin B activity in eye tissue was determined by cathepsin assay. Results The animal model of retinal neovascularization was established successfully in C57BL/6J mouse. The number of vascular-endothelial-cells extending inner-limiting membrane was 2.71 ± 1.07 and 67. 51 ± 11.55 respectively in control group and experiment group,with a significant difference between two groups （ t = 79.02, P 〈 0. 01 ）. The non-vessel area of mice was （ 1. 17 ± 0. 30 ） mm^2 and （5.34 ± 0. 74 ） mm^2 in control group and experiment group respectively,showing a significant difference between two groups （t = 65.40, P 〈 0. 01 ）. The ratio of the nonvessel area of retina and the whole retina area was （0. 09 ±0.01 ） mm^2 and （0.24 ±0.03） mm^2 respectively in control group and experiment group with a significant difference between two groups（ t = 15.00 ,P 〈 0. 01 ）. The mean optical density of Cathepsin B in mouse retina was 0. 24 ± 0.02 and 0. 35 ± 0.05 respectively in control group and experiment group with considerable difference between them （ t = 35.48, P 〈 0. 01 ）. The Cathepsin B activity in ocular tissue was 17.75 ± 2.30 nmol/（ min ·mg） protein and 28.75 ± 3. 14 nmol/（ min· mg） protein in control group and experiment group respectively（ t = 8.33, P 〈 0. 01 ）. Conclusion The activity and level of Cathepsin B in retina are enhanced in retinal neovasculartion animal model,indicating that Cathepsin B may be an important factor of retinal neovasculartion.