小鼠角膜碱烧伤行羊膜移植对MMP-9、TIMP-1在新生血管形成中的影响

目的探讨小鼠角膜碱烧伤行羊膜移植对基质金属蛋白酶9(matrixmetalloproteinase9,MMP9)、金属蛋白酶组织抑制剂1(tissueinhibitorofmetalloproteinase1,TIMP1)在新生血管形成中的影响以及MMP9及TIMP1在角膜新生血管形成中的作用。方法昆明小鼠40只,随机分为实验组和对照组,每只鼠均取右眼为实验眼。采用1mol·L-1NaOH溶液烧伤小鼠角膜,建立炎症性角膜碱烧伤动物模型。对实验组小鼠右眼角膜行羊膜移植,对照组不行羊膜移植。分别在羊膜移植后的0d、2d、7d、14d处死2组小鼠,摘除右眼球,行免疫组织化学染色并用计算机图像分析系统检测2组小鼠MMP9及TIMP1在角膜中的分布及其平均吸光度值的变化。结果免疫组化结果:对照组碱烧伤角膜后第2d,可见MMP9出现表达,第7dMMP9的染色较第2d增强,基质层可见大量新生血管,且血管内皮细胞可见表达,14d达高峰;TIMP1开始表达不明显,第7d出现表达,14d达高峰。羊膜移植组各时间点MMP9表达低于对照组,而TIMP1表达高于对照组。结论碱烧伤后小鼠角膜中MMP9表达增加,在新生血管形成的过程中起一定作用。羊膜可能具有抑制MMP9在碱烧伤小鼠角膜中表达的作用,而且羊膜同时促使TIMP1在后期表达水平升高,从而抑制MMP9的活性,抑制和减缓碱烧伤后角膜新生血管的发生和发展。

Expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in alkali-burned mouse corneal neovascularization form model after amniotic membrane transplantation

Objective To study the expressions and role of matrix metalloproteinase-9(MMP-9) and its tissue inhibitor(TIMP-1)in mice with corneal alkali burn induced corneal neovascularization after amniotic membrane transplantation.Methods Forty KM mice were divided into two groups (experimental group and control group) and their right eye corneas were burned with alkali.Amniotic membrane transplantation (AMT) was performed in experimental group.At different time points (0 day,2 days,7 days,14 days)after AMT,all mice were killed and the expressions of MMP-9 and TIMP-1 in cornea were detected immunohistochemically,and the results were analyzed by computer medical image analysis system.Results In the control group,MMP-9 and TIMP-1 were expressed in the epithelial cells and stromal and exudated inflammatory cells.The level of MMP-9 elevated from the 2nd day,peaked on the 14th day.TIMP-1 was expressed on the 7th day,peaked on the 14th day,and was decreased gradually to the base line level.At the same time point,the level of MMP-9 in AMT group was greatly lower than that in control group,while the level of TIMP-1 AMT group was greatly higher than that in control group.Conclusion Corneal alkali burn induce the improving expression of MMP-9,which plays the role in corneal neovascularization.AMT level can restrain the expression of MMP-9 in cornea,and at the same time AMT facilitate the expression level of TIMP-1 in the late inflammation stage,thus inhibiting MMP-9 activity and alleviating the onset and development of corneal neovascularizaton.