激光诱导小鼠脉络膜新生血管中补体C3的作用

Role of complement C3 in laser-induced choroidal neovascularization of rat

目的探讨激光诱导脉络膜新生血管(choroidal neovasculature,CNV)形成机制中补体的作用。方法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,共聚焦显微镜下观察CNV发生情况,检测补体溶血活性(CH50),用免疫组织化学方法检测补体C3,用RT-PCR分析C3a受体mRNA的表达。结果激光后第7天,对照组C57BL/6小鼠见CNV形成,而眼镜蛇毒因子(cobra venom factor,CVF)预处理组及C3-/-小鼠组未见CNV形成。CVF预处理组小鼠补体的CH50于激光后第1天、第3天、第5天、第7天分别为2%、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1天,对照组RPE-脉络膜-巩膜复合体见C3强阳性染色,CVF预处理组及C3-/-小鼠组未见C3阳性染色。激光后对照组C57BL/6小鼠较激光前,C3a受体mRNA表达增强,激光后第5天,C3a受体mRNA水平达到高峰,并在激光后第7天维持较高水平,而CVF预处理组小鼠及缺乏补体C3的C3-/-小鼠组激光前后未见明显改变。结论氪激光诱导CNV模型,补体C3参与CNV形成。补体系统的存在和激活是激光诱导CNV形成的必要条件。

Objective To study the role of complement C3 in laser-induced choroidal neovascularization（CNV） of rat.Methods CNV model was established by experimental laser photocoagulation with the krypton red laser,the incidence of CNV was determined by confocal microscope,the hemolysis activity（CH50） of complement was detected,and the complement C3 was tested by immunohistochemical method,RT-PCR analysis was used to examine the expression of C3R mRNA.Results At 7 days after laser treatment,CNV was induced successfully in C57/BL6 mice of control group,but no CNV was found in CVF pre-treated group and C3-/-rat group.The CH50 of complement in CVF pre-treated group at 1 day,3 days,5 days,7 days after laser treatment were 2%,3%,3% and 2%,respectively,which in control group were all 100%,there were significant differences（all P0.001）.At 1 day after laser treatment,the complement C3 was strong positive stained in RPE-choroid-scleral complex of control group,but negative stained in CVF pre-treated group and C3-/-rat group.In C57/BL6 mice of control group,C3R mRNA level after laser treatment higher than that before laser treatment,peaked at 5 days,and sustained the high level at 7 days after laser treatment,but there was no change in CVF pre-treated group and C3-/-rat group before and after laser treatment.Conclusion The complement C3 takes part in the CNV formation,the presence and the activation of complement system are essential for the development of laser-induced CNV in mice.