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.