Abstract:

BACKGROUND: Studies has demonstrated that cyclooxygenase-2 (COX-2) and matrix metalloproteinase-2 (MMP-2) may play an important role in corneal neovascularization (CNV), but their mechanisms and interactions remain unclear.  
OBJECTIVE: To investigate the expressions of COX-2 and MMP-2 in suture-induced CNV, and to analyze the interaction between COX-2 and MMP-2, additionally, to explore the mechanisms of CNV. 
METHODS: The models of CNV were induced by corneal stitch. The development of CNV was monitored daily under slit-lamp microscope. The expressions of COX-2 and MMP-2 and levels of COX-2 and MMP-2 mRNA in CNV were detected by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR) at days 1, 4, 7, 14 and 21 after operation, and their correlations were analyzed.
RESULTS AND CONCLUSION: New vessels appeared near corneal limbus and grew towards into transparent cornea at 3-4 days after stitching. The stitch sites were edematous. The neovascular thrived and edema increased at 7 days. The neovascular reached to stitch sites at 14 days, and then vascular net formed. Then vessels gradually became thinner at 21 days. Immunochemistry and RT-PCR demonstrated: the positive expressions of COX-2 and MMP-2 in CNV localized in inflammatory cells and endothelial cells of neovascularization progressed gradually after stitching, and involved the entire cornea at the 7 day post-treatment. After 7 days the expression decreased following the decrease of inflammatory cells. The expression of COX-2 was correlative with MMP-2 positively (r=0.981, P < 0.05). All results demonstrated that in inflammation-associated corneal angiogenesis, expression of COX-2 and MMP-2 progressed and closely related to the angiogenesis.