Abstract
Purpose::
Best disease, like age-related macular degeneration and other maculopathies, primarily affects a relatively small portion of the retina, the macula. Other retinal diseases primarily spare the macula from degeneration. The biological basis for why the lesions in Best disease develop in the macula is not well understood. In this study we sought to determine whether differences exist between the macular and peripheral expression of the responsible gene, VMD2/bestrophin, in human donor eyes.
Methods::
The localization and expression of bestrophin was evaluated in a series of normal and diseased human eyes using immunohistochemistry (n=22), quantitative RT-PCR (n=3) and Western blotting (n=9). Macular and extramacular regions were evaluated and compared. We also examined the macular and peripheral expression of CD29 and RPE65 by immunohistochemistry and Western blotting, respectively.
Results::
Bestrophin expression in the macula was significantly less robust than extramacular expression as assessed by immunohistochemistry (18 of 22), RT-PCR (3 of 3), and Western blot analysis (8 of 9). In contrast, macular-extramacular variability was not noted for CD29 and RPE65.
Conclusions::
The regional pattern of gene expression in the human eye may in part explain the reason that bestrophin mutations lead to macula-specific lesions. Although Best disease shows a dominant pattern of inheritance, these findings suggest that Best disease results in macula-specific lesions due to an insufficiency of functional bestrophin protein in the macular RPE.
Keywords: macula/fovea • gene/expression • retinal degenerations: hereditary