大鼠角膜碱烧伤行培养角膜上皮移植后VEGF的表达

Expression of vascular endothelial growth factor in rat cornea after corneal epithelium transplantation for alkali burn

目的研究角膜上皮培养移植后角膜新生血管(CNV)形成和血管内皮生长因子(VEGF)的变化特点。方法对角膜碱烧伤CNV大鼠行培养角膜上皮移植,观察术后CNV程度,RT-PCR和免疫组织化学法检测术后24、48、72、168h角膜组织VEGF的表达。结果实验组角膜上皮移植后14dCNV接近瞳孔区,之后逐渐减退。移植后24h角膜VEGFmRNA的相对含量为1.20±0.09;48h为1.91±0.03;72h为2.34±0.11;168h为1.83±0.14。角膜上皮和基质均表达VEGF蛋白,以上皮层表达为主,并随时间推移表达量增加。结论培养角膜上皮移植后24h角膜可表达VEGF,72h表达量最高。VEGF表达与培养角膜上皮移植后CNV的发生密切相关。

Objective Corneal opaeification induced by corneal neovaseularizatiou （CNV） is one of major causes of blindness. It is believed thai vascular endutheliat growlh taetor（VEGF） play a key rote in the coarse of CNV. The purpose of this paper was to detect the expression of VEGF in rat corneas after cauterization with alkali and discuss the relationship of CNV and expression of VEGF. Methods CNV was induced by cauterization with 1 mol/L sodium hydroxide in 20 Sprague Dawtey rats. The animals were randomized inlo treated group and control group respectively. Twelve rats in treated group received cultured corneal epithelimn transplantation aider debridement of CNV tissue,and the CNV tissue were debrided in 8 rats in control group without corneal epithelium transplantation. The level of VEGF retINA and protein in the lesions were examined by RT-PCR and immnnohisloehemistry in 24,48,72 and 168 hours. Results CNV of rats in treated group grew densely within 14 days, The expression ofYEGF mRNA at each tilne point （24,48,72 and 168 hours） after eorneal epithelium transplantation was 1.20 ±0.09, 1. 91±0. 03,2.34± 0.1 1 and 1. 83±0. 14, indicating that after cultured corneal epithelium h-ansplantalion, the expression of YEGF was initially （Mserved at 24 hours, and then began to increase and reached peak at 72 hours, lmmnnohistnehemistry revealed that VEGF positive cells in cornea were increased with prolong of lransplantation time. Conclusion The increase of VEGF is correlated with the proliferation of CNV.