Pigment Epithelium-Derived Factor (PEDF) and Vascular Endothelial Growth Factor (VEGF) in Human Choroidal Neovascular Tissues

Abstract

Abstract: : Purpose:PEDF is a protein produced by the retinal pigment epithelial (RPE) cells. Recent studies have implicated that PEDF in activities are inhibitory to angiogenesis. In this study, we investigated the expression of PEDF in human choroidal neovascular membranes (CNVMs) and compared it to the expression of vascular endothelial growth factor (VEGF). Methods:Choroidal neovascular tissues were obtained at vitrectomy from 7 eyes of 7 patients. CNVMs of several origins were obtained: six age-related macular degeneration (ARMD) and one angioid streaks. Specimens were processed for paraffin-embedded sections. Immunoperoxidase analysis for was carried out to detect the expression of PEDF and VEGF on prepared sections with a LSAB kit (DAKO, Glostrup, Denmark) according to the manufacturer's protocols. Results: PEDF protein and also VEGF protein were strongly detected in the RPE cells and endothelial cells in CNVMs that presented subretinal hemorrhage and/or remarkable hyper-fluorescence by fluorescein angiograms,those suggest active neovascular membranes.Whereas PEDF and VEGF were weakly detected only in the RPE cells that proliferated and covered the CNVMs when CNVMs were quiescent and fibrosis was predominantly observed clinically and histopathologically. Conclusions:Immunoreactivity for PEDF and VEGF was observed in RPE cells and endothelial cells in CNVMs. Our results suggest that the expression of PEDF and VEGF may play a major role in mediating human CNVMs.

Keywords: choroid: neovascularization • immunohistochemistry • age-related macular degeneration