小鼠氧诱导视网膜新生血管形成中EphA2与VEGF的表达及相关性研究

Expression of Eph A2 and VEGF in the mouse model of oxygen-induced retinopathy

目的探讨促红细胞生成素产生肝细胞受体A2(Eph A2)与血管内皮生长因子(VEGF)在C57BL/6小鼠氧诱导视网膜新生血管病变模型(OIR)中的表达以及相关性。方法新生C57BL/6小鼠120只,随机分为实验组和对照组,每组各60只。实验组小鼠建立OIR模型,对照组饲养于正常氧环境。各组小鼠于出生后第17天处死,将小鼠眼球行组织切片后HE染色,计数突破视网膜内界膜新生血管内皮细胞核数。放射免疫法检测小鼠视网膜组织Eph A2和免疫组织化学染色检测视网膜VEGF含量,分析二者的相关性及与视网膜新生血管的关系。结果实验组视网膜大量新生血管形成,实验组小鼠视网膜切片新生血管细胞核计数明显高于对照组(99.10±3.15/个比4.20±0.89/个),差异有统计学意义(t=28.53,P<0.01)。各组视网膜中Eph A2的ELISA检测结果:实验组Eph A2含量明显高于对照组(80.82±20.70 pg/ml比14.42±6.80 pg/ml),差异有统计学意义(t=23.23,P<0.01)。视网膜免疫组织化学染色显示,VEGF实验组视网膜组中表达明显升高,在对照组小鼠视网膜有微弱表达,实验组VEGF吸光度值高于对照组(5.19±0.75比1.88±0.33),差异有统计学意义(t=13.42,P<0.05)。Eph A2和VEGF两者的表达显著相关(r=0.85,P<0.05)。结论 Eph A2与VEGF的表达在小鼠视网膜新生血管形成中呈正相关,提示两者可能存在协同效应。

Objective To analyze the expression of EphA2 and VEGF in a mouse model of oxygen induced retinopathy and then evaluate their relationship. Methods Totally 120 neonates of C57VL/ 6 mouse were randomly divided into experiment group（n = 60）and control group （n = 60）and OIR models were established in the experiment group. The neonates in the control group were kept in the room air condition. All the mice were sacrificed at P17. The eyes were made into pathological sections for observing and counting the number of vascular cell nuclei on the vitreal side of the internal limiting membrane. And radioimmunoassay was used to compare the EphA2 content of the retina tissue. Immunohistochem-istry analysis of VEGF protein levels in the retina had been done in control mice and the OIR mice. Results The histopathological sections of retina showed the number of retinal neovascular endothelial nuclei was 99. 10 ± 3. 15 in the OIR mice and 4. 20 ± 0. 89 in the control group. There was statistically significant difference between those two groups（ P 〈 0. 05）. EphA2 radioimmunoassay indicated that the EphA2 content in experiment group was 80. 82 ± 20. 70 pg/ ml,but 14. 42 ± 6. 80 pg/ ml in the control group（ P 〈 0. 05）. The expression of VEGF in the retina of OIR mice were stronger than the control group（ P 〈 0. 05）. There was a positive correlation between the expression of EphA2 and VEGF（ P 〈 0. 05）. Conclusion EphA2 and VEGF may interact with each other in the formation of retinal neovascularization.