摘要：
目的 研究在光照损伤作用下TgAPPswePS1转基因鼠脉络膜新生血管形成情况.方法 以20只6个月龄阿尔茨海默病转基因鼠(TgAPPswePS1鼠)为研究对象,其中12只行10 000 lux光照处理,每天光照12 h、连续光照6个月为实验组,余8只不作处理为对照组,实验组与对照组小鼠在实验结束时进行取材,切片行HE染色及甲苯胺蓝染色观察视网膜各层结构改变,测量新生血管形成数量,同时检测实验组与对照组视网膜色素上皮(retinal pigment epithelium,RPE)铺片上p-淀粉样蛋白(β-amy-loid protein,Aβ)与血管内皮生长因子表达情况,予以定量并进行统计学分析.结果 与对照组比较,光照6个月后,实验组小鼠视网膜发生明显改变,其中以外核层与光感受器层变化最明显;RPE细胞出现空泡、色素不均一、细胞间的连接断裂等改变,视网膜切片上可见脉络膜新生血管突破RPE进入视网膜内,对新生血管进行统计,发现脉络膜新生血管发生率为18.75％.光照损伤后,血管内皮生长因子在实验组RPE上呈阳性表达,可见细胞浆内弥散性表达和沿血管壁的阳性染色,较对照组表达量增加(6.59±1.14)倍,差异有统计学意义(P＜0.05).Aβ在实验组的RPE铺片上存在强阳性表达,通过Z-stack检测发现Aβ沉积类似Drusen状,位于RPE下;而对照组中未见此类免疫阳性反应,与对照组比较Aβ沉积增加(6.45±2.93)倍,差异存在统计学意义(P＜0.05).结论 强光光照损伤TgAPPswePS1鼠后,视网膜存在明显变化,可发生脉络膜新生血管,提示阿尔茨海默病转基因鼠在光照损伤下可以作为脉络膜新生血管的一种动物研究模型.%Objective To research the choroidal neovascularization (CNV)in TgAPPswePS1 transgenic mice after intensive light exposure injury.Methods Twenty TgAPPswe/PS1 transgenic mice at the age of 6 months were grouped for experiments.The treated groups of 12 mice were treated by a source of 10 000 lux cool full spectrum light for 6 months,12 hours per day;While the control groups of 8 mice were kept in normal conditions.The mice eyes of the experimental group and control group were examined with HE/Toluidin blue staining,the retinal structure was observed,and the number of CNV was counted.The expression of VEGF and Aβ were examined with immunofluorescence on the retinal pigment epithelial (RPE) flat mount.All of the results were quantified and statistically analyzed.Results After treated by 6 months of intensive light exposure in the experimental group,histopathological analysis has found significant loss of outer nuclear layer/photoreceptor out segment and outer plexiform layer as compared with the control group;At the same time,abnormal hypo-and hyper-pigmentation,vacuoles and disruption in the RPE layer,remarkable CNV were found in the experiment group by Toluidin blue staining,and the incidence of CNV was 18.75％.The VEGF expression domenstrated.a diffusive and deposition pattern along the neovessels which showed a significant increase of (6.59 ± 1.14) fold changes as compared with the control group.The difference was statistical significant (P ＜ 0.05).Then the Aβ deposits were positive expressed in the RPE layers after intensive light exposure treatment,and pathological deposition of Aβ in the RPE showed plaque like displayed by confocal Z-stack microscopy,and the drusenoid Aβ deposits were found alone with the neovessels on the RPE flat mount.The deposition of Aβ protein increased with (6.45 ± 2.93) fold changes as compared with the control group,and the difference was statistical significant.Conclusion CNV with degenerative changes in the outer retina can be induced by intensive light exposure in the APPswe/PS1 transgenic mouse.These results suggest that an Alzheimer's transgenic animal model might be an alternative animal model for CNV if combined with intensive light exposure.
