补体和膜攻击复合物在脉络膜新生血管形成中的作用

Effect of complement and membrane attack complex in choroidal neovascularization

目的探讨激光诱导的C57BL/6小鼠脉络膜新生血管(choroidal neovascularization,CNV)形成机制中补体的角色及补体膜攻击复合物(membrane attack complex,MAC)的表达。方法 实验分为对照组、CVF预处理组、C3-/-小鼠组。用氪红激光对小鼠行实验性视网膜激光光凝,建立CNV动物模型,小鼠于光凝后第7天,用FITC-葡聚糖荧光素灌注心脏;单克隆特定抗体标记RPE-脉络膜-巩膜复合体铺片,共聚焦显微镜观察CNV发生率,免疫组织化学分析MAC表达。结果 CVF处理组小鼠补体CH50水平光凝后第1天、第3天、第5天、第7天分别为3%、3%、3%、2%,同时间点对照组均为100%,差异均有显著统计学意义(均为P<0.001)。激光后第7天,对照组小鼠见CNV形成,而CVF预处理组及C3-/-组小鼠未见CNV形成。激光后第1天,对照组C57BL/6小鼠RPE-脉络膜-巩膜复合体见MAC强阳性染色,CVF预处理组及C3-/-小鼠组未见MAC阳性染色。结论 氪激光诱导CNV模型,补体的存在和激活、MAC的沉积是激光诱导CNV的必要因素。

Objective To study the role of complement and express of membrane attack complex（MAC） in laser-induced choroidal neovascularization（CNV） in C57BL/6 mouse.Methods Animals were divided into control group,CVF-treated group and C3-/-group.CNV was induced by laser photocoagulation with the krypton red laser.Animals from each group were sacrificed and perfused through the heart with fluorescein-labeled dextran（FITC-dextran） at the 7th day after laser photocoagulation.RPE-choroid-scleral flat mounts were stained for elastin and MAC.The incidence of CNV was determined by confocal microscope.Expression of MAC was detected by immunohistochemical method.Results The level of CH50 at the 1st day,3rd day,5th day,7th day in CVF-treated group were 3%,3%,3%,2%,which in control group were all 100%,there were significant differences（All P0.001）.At the 7th day after laser photocoagulation,CNV was induced in control group,but CNV did not appear in CVF-treated group and C3-/-group.The intense positive red staining for MAC was observed in C57BL/6 mice in control group at the 1st day after laser photocoagulation,but no positive MAC staining was observed in CVF-treated group and C3-/-group.Conclusion The presence and the activation of the complement,the deposition of MAC are essential for the laser induced CNV in mice.