Abstract
Abstract: :
Purpose:To determine gene expression changes found in a mouse model of oxygen induced retinopathy by using the gene microarray technology. Methods:C57BL/6J neonatal mice were exposed to 75% oxygen from postnatal day 7 to 12 and then returned to the room air. Control mice were kept in room air. Fluorescein angiography was used to determine the day on which oxygen induced retinal neovascularization occurs. The mice exposed to oxygen were anesthetized and 50mg/ml fluorescein dextran was injected into the left ventricle. The retinas were isolated and flat mounted on a slide glass to evaluate the vascular pattern. The light microscopic analysis of retina was also performed. The eyes were enucleated from control mice and mice of oxygen induced retinopathy. The retinas were isolated and mRNA was purified from the retinas, labeled and hybridized to Affimetrix microarray chips for analysis of gene expression levels. Results:On postnatal day 15, fluorescein-dextran angiography showed occurrence of neovascularization at the junction between the perfused and the nonperfused retina in the midperiphery. By the light microscopic analysis, neovascular tufts were seen protruding into the vitreous space in the mice exposed to oxygen. The microarray used in this study contains 12488 of mouse cDNA and expressed sequence tags (ESTs). Of those, 129 cDNA and ESTs (1.03%) showed significant changes (over 2-fold) in expression between hyperoxia and normoxia groups. Expression changes of 49 genes including vascular endothelial growth factor, insulin-like growth factor and heat-stress related proteins were upregulated up to 33.9 fold change, while 80 genes showed downregulated expression less than 7.5 fold change. Conclusion:The microarray analysis is useful to profile changes in gene expression in the process of retinal neovascularization.
Keywords: 417 gene/expression • 566 retinal neovascularization • 572 retinopathy of prematurity