Effect of Vascular Endothelial Growth Factor(VEGF) on the Corneal Neovascularization and Expression of MMP-2, 9, TIMP-1, 2 and flk-1

ABSTRACT

PURPOSE: The purpose of this study is to clarify the degree of corneal neovascularization and its expression of MMP-2. 9(matrix metalloproteinase) and TIMP-1, 2(tissue inhibitor of metalloproteinases) according to the different concentrations of VEGF(vascular endothelial growth factor). METHODS: After the pellets with different amounts of VEGF(VEGF 125, 250 ng) were inserted into the corneal stroma of rat model, their degree of corneal neovascularization and the expression of MMP-2, 9 and TIMP-1, 2 were compared with those of control group where pellets were filled with phosphate-buffered saline. RESULTS: At the 7th day after the pellet insertion, degree of neovascularization was most highly scored in the group with pellet which contained the largest amount of VEGF, 250 ng, and there was statistically noticeable increase of eovascularization with the increase of VEGF amount(P<0.05). On immunohistochemical staining, as the amount of VEGF increases, not only MMP-2, 9 and flk-1, but also TIMP-1, 2 were expressed more. CONCLUSIONS: In conclusion, when it comes to neovascularization, MMP-2, 9, which induces angiogenesis, as well as its inhibitor TIMP-1, 2 are increased to maintain the homeostasis of the cornea.