Abstract
Abstract: :
Purpose: PEDF has been shown to be an inhibitor of angiogenesis as well as a multipotent neurotrophic factor in the mammalian eye. Changes in PEDF have been correlated with development of retinal neovascularization in oxygen-induced retinopathy. The purpose of this study was to determine the expression of PEDF in normal human retina and choroid using immunohistochemistry and evaluate the changes in PEDF localization in proliferative sickle retinopathy. Methods: Cryopreserved tissues from eyes of normal subjects and subjects with proliferative sickle cell disease were used with streptavidin peroxidase immunohistochemistry. A rabbit polyclonal antibody was made against recombinant human PEDF. Binding of the antibody was blocked by preincubation of the antibody with excess human recombinant PEDF. Results: The most prominent site of PEDF localization in the normal eye was condensed vitreous at the internal limiting membrane and RPE-Bruch's membrane-choriocapillaris complex. PEDF was also prominent in choroidal stroma. There was also limited immunoreactivity in the neural retinas in some blood vessels and in the interphotoreceptor matrix. In eyes with proliferative sickle cell disease, prominent immunostaining was present in viable and atrophic regions of the sea-fan formations. Conclusion: PEDF was most prominent in cortical vitreous and choroid. PEDF staining was prominent in sea fan formations with both viable and nonviable blood vessels. We have previously demonstrated that viable sea fan formations have high VEGF levels (BJO 83:838, 1999), so the effect of PEDF in sea fans may be offset by the high levels of VEGF. In all specimens, the most prominent sites of PEDF localization were tissues rich in matrix components.
Keywords: 423 growth factors/growth factor receptors • 566 retinal neovascularization