As_2O_3对角膜新生血管中VEGF表达的影响

Effect of As_2O_3 on expression of VEGF in corneal neovascularization

目的探讨角膜新生血管形成的不同时期血管内皮生长因子(vascular endothelial growth factor,VEGF)在角膜内的表达,研究三氧化二砷(As2O3)对VEGF表达的影响。方法健康日本大耳白兔48只,碱烧伤法建立兔角膜碱烧伤动物模型,随机分成实验组(1组、2组、3组)和对照组,每个小组各12只。1、2、3组分别给予0.1mL、0.3mL、0.5mL As2O3结膜下注射;对照组给予生理盐水0.3mL结膜下注射。免疫组织化学法及反转录-聚合酶链反应法检测碱烧伤后第7天、第14天、第28天各组角膜内VEGF的表达。结果兔角膜碱烧伤后,采用免疫组织化学法检测1组、2组、3组、对照组角膜新生血管中VEGF表达:第7天时阳性细胞所占百分比分别为(1.90±0.64)%、(1.30±0.54)%、(0.60±0.59)%、(5.80±0.90)%;第14天时分别为(3.60±0.86)%、(2.60±0.74)%、(1.60±0.75)%、(8.50±0.83)%;第28天时分别为(1.30±0.75)%、(1.00±0.38)%、(0.30±0.59)%、(3.20±0.65)%。反转录-聚合酶链反应法检测1组、2组、3组、对照组角膜新生血管中VEGF表达量:第7天时分别为(168.18±11.50)μg、(110.57±11.89)μg、(35.58±8.56)μg、(249.58±13.34)μg;第14天时分别为(195.42±11.58)μg、(145.58±12.36)μg、(59.52±5.28)μg、(329.48±11.69)μg;第28天时分别为(111.58±9.56)μg、(87.25±6.06)μg、(25.26±6.54)μg、(194.85±13.24)μg。2种检测结果显示:角膜新生血管中VEGF表达量初期逐渐增加,第14天时达高峰,以后随时间延长逐渐减少,且随As2O3剂量的增加其表达量减少;实验组角膜组织中各时间点VEGF的表达水平低于对照组,差异均有统计学意义(均为P<0.05)。结论VEGF是重要的角膜新生血管形成因子,As2O3对碱烧伤后兔VEGF的表达具有抑制作用;抑制VEGF的表达是As2O3抑制角膜新生血管形成的重要机制。

Objective To investigate the expression of vascular endothelial growth factor（VEGF）in corneal neovascularization at different periods of corneal neovascularization,and to explore the effect of As2O3 on the expression of VEGF.Methods About 48 healthy Japanese rabbits were used to eatablish corneal alkali burn models by alkali burn,and were randomly divided into experimental groups（group 1,group 2 and group 3）and control group,12 rabbits in each group.Rabbits of group 1,group 2 and group 3 were treated with subconjunctival injection of 0.1 mL,0.3 mL and 0.5 mL As2O3,and rabbits of control group were treated with subconjunctival injection of 0.3 mL sodium chloride.The expression of VEGF in corneal neovascularization were measured with immunohistochemical method and reverse transcription-polymerase chain reaction method at the 7th day,14th day and 28th day after alkali burn.Results After alkali burn,the percentage terms of positive expression of VEGF in corneal neovascularization of group 1,group 2,group 3 and control group with immunohistochemical method were（1.90±0.64）%,（1.30±0.54）%,（0.60±0.59）% and（5.80±0.90）% at the 7th day after alkali burn,were（3.60±0.86）%,（2.60±0.74）%,（1.60±0.75）% and（8.50±0.83）% at the 14th day after alkali burn,were（1.30±0.75）%,（1.00±0.38）%,（0.30±0.59）% and（3.20±0.65）% at the 28th day after alkali burn;The expression of VEGF in corneal neovascularization of group 1,group 2,group 3 and control group with the reverse transcription-polymerase chain reaction method were（168.18±11.50）μg,（110.57±11.89）μg,（35.58±8.56）μg and（249.58±13.34）μg at the 7th day after alkali burn,were（195.42±11.58）μg,（145.58±12.36）μg,（59.52±5.28）μg and（329.48±11.69）μg at the 14th day after alkali burn,were（111.58±9.56）μg,（87.25±6.06）μg,（25.26±6.54）μg and（194.85±13.24）μg at the 28th day after alkali burn.The two methods showed that the expression of VEGF in corneal neovascularization was gradually increased at the early stage,went to peak at the 14th day,then decreased with the prolonging of time and the increase of As2O3;VEGF levels at different time points in experimental groups were lower than those in control group,and there were statistical differences（All P0.05）.Conclusions VEGF is an important corneal neovascularization factor;As2O3 can inhibit the formation of VEGF after alkali burn;Inhibition of VEGF is an important mechanism for As2O3 inhibiting corneal neovascularization.