Abstract
Purpose: :
Light exposure can progress several kinds of retinal diseases, such as retinitis pigmentosa and age-related macular degeneration. The pathogenesis of these diseases involves not only the changes of the neural retina, but retinal pigment epithelium. In this study, we analyze the changes of retinal pigment epithelium after light exposure, focusing on beta-catenin. It can translocate into the nucleus and induce proliferation, migration, and expression of inflammatory cytokines, which may be involved in pathogenesis of retinal diseases.
Methods: :
BALB/c mice (6~8 weeks old) were purchased and kept under dim cyclic light (5 lux, 12 h on/off). The mice were dark-adapted by keeping them in complete darkness for 12 hours, and then exposed to a white fluorescence lamp (3000 lux or 5000 lux). Retinal sections were stained with hematoxylin and eosin, and flat-mount retinal pigment epithelium was stained with anti-beta-catenin antibody.
Results: :
Thinning of the neural retina was observed after 5000 lux of light exposure, but not after 3000 lux of light exposure. No obvious morphological changes were observed in retinal pigment epithelium in the sections of both conditions. However, in the flat-mount samples, retinal pigment epithelium showed nuclear translocation of beta-catenin after 3000 lux of light exposure, while in the non-light exposed mice, beta-catenin is observed subcellularly.
Conclusions: :
The translocalization of beta-catenin which has a potential of pathogenic change was induced after light exposure in retinal pigment epithelium.
Keywords: retinal pigment epithelium • cell adhesions/cell junctions