Retinal Vascular Development and Pathologic Retinal Angiogenesis Are Not Impaired in Matrix Metalloproteinase-2 Deficient Mice

Abstract

Purpose: Earlier studies have suggested a role for metalloproteinase-2 (MMP-2) in retinal angiogenesis. To investigate this further, we have studied retinal vascular development and pathologic ischemia-induced retinal angiogenesis in MMP-2–deficient and wild-type mice. Methods: Vascular development of the retina was studied in retinal flatmounts, whereas pathologic retinal angiogenesis was analyzed in retinal flatmounts and on histologic sections using a model of ischemia-induced retinopathy. The time course of MMP-2 mRNA expression was determined by in situ hybridization and real-time polymerase chain reaction (PCR). Results: Formation of the retinal vascular plexus was not significantly different in MMP-2–deficient mice as compared to wild-type mice. In ischemia-induced retinopathy, there was an increased formation of extraretinal neovascular tufts in the MMP-2–deficient mice (p < 0.05). MMP-2 mRNA expression did not correlate to either retinal vascular development or to ischemia-induced formation of extraretinal vascular tufts. Conclusions: The current data suggest that MMP-2 is not essential for either retinal vascular development or pathologic retinal neovascularization in the mouse.