Becker M D, Kruse F E, Azzam L, Nobiling R, Reichling J, Völcker H E
Department of Ophthalmology, University of Heidelberg, Germany.
Invest Ophthalmol Vis Sci. 1999 Mar;40(3):612-8.
Numerous investigations have stressed the significance of leukocytes in early angiogenesis. Leukocytes invade the cornea, and the location of their extravasation corresponds to the site of vessel ingrowth. The interactions between leukocytes and vascular endothelium are mediated by various proteins, including adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1). In this study, the role of ICAM-1 during early corneal angiogenesis was evaluated in vivo.
Corneal neovascularization was induced in New Zealand White rabbits by use of intrastromal pellets containing 750 ng vascular endothelial growth factor (VEGF). The fluorescent dye rhodamine 6G was used to stain leukocytes in vivo. Leukocyte adhesion and vessel growth were quantified in vivo by high-resolution fluorescence angiography. To inhibit ICAM-1 interactions a microemulsion containing anti-ICAM-1 antibody was applied topically.
Limbal vessels showed increased leukocyte adhesion 24 hours after pellet implantation: The number of rolling and sticking leukocytes was significantly increased compared with the number in control animals (P < 0.01). Treatment with anti-ICAM-1 antibody resulted in reduced leukocyte sticking and increased leukocyte rolling. The area covered by new blood vessels was significantly diminished in eyes treated with anti-ICAM-1 (P < 0.05).
The results support the hypothesis that ICAM-1-mediated leukocyte adhesion is a key event in early angiogenesis. This model may serve for investigation of the significance of adhesion molecules by in vivo observation and quantification.
众多研究强调了白细胞在早期血管生成中的重要性。白细胞侵入角膜，其渗出位置与血管向内生长的部位相对应。白细胞与血管内皮之间的相互作用由多种蛋白质介导，包括细胞间黏附分子-1（ICAM-1）等黏附分子。在本研究中，在体内评估了ICAM-1在早期角膜血管生成中的作用。
通过使用含有750 ng血管内皮生长因子（VEGF）的基质内微丸诱导新西兰白兔角膜新生血管形成。荧光染料罗丹明6G用于在体内对白细胞进行染色。通过高分辨率荧光血管造影术在体内对白细胞黏附和血管生长进行定量。为抑制ICAM-1相互作用，局部应用含有抗ICAM-1抗体的微乳剂。
植入微丸24小时后，角膜缘血管显示白细胞黏附增加：与对照动物相比，滚动和黏附的白细胞数量显著增加（P < 0.01）。用抗ICAM-1抗体治疗导致白细胞黏附减少，白细胞滚动增加。用抗ICAM-1治疗的眼睛中新生血管覆盖的面积显著减小（P < 0.05）。
结果支持以下假设，即ICAM-1介导的白细胞黏附是早期血管生成中的关键事件。该模型可用于通过体内观察和定量研究黏附分子的重要性。
