Abstract
Purpose: :
Ocular neovascularization is the pathological hallmark of many retinopathies, but its molecular mechanisms remain unclear. Although the risk of light for age-related macular degeneration (AMD) has long been clinically and statistically investigated, the role of light in the pathogenesis of retinal disease remains elusive. In this study, we investigated the effects of visible light exposure on the vascular endothelial growth factor (VEGF) gene expression in normal mouse and vitamin A- lacked mouse.
Methods: :
Total RNA prepared from retina of mice or vitamin-A lacked mice, with or without fluorescent light exposure, was subjected to RT-PCR and real-time PCR analyses. The level of vitamin A in serum of normal mice and vitamin-A lacked mice given special foods for 4 months was investigated using HPLC analyses. The ERG was performed for the both of groups.
Results: :
Light exposure caused a significant increase in VEGF transcripts in the retina of mice stimulated with fluorescent light in a time-dependent manner. Such an increase in VEGF expression was inhibited by the lack of vitamin A, which was also confirmed using ERG.
Conclusions: :
These data indicate that light exposure increases VEGF expression through the mechanisms involving activation of retinoic signaling in retina of mice. This study provides the first evidence that visible light may play a causative role in the pathogenesis of neovascularization of the retinal and choroidal tissues.
Keywords: retina • age-related macular degeneration • vascular endothelial growth factor