The Distribution of Neural Progenitor Cells in Surgically Excised Choroidal Neovascular Membranes Associated With Age–Related Macular Degeneration

Abstract

Abstract: : Purpose: Nestin is an intermediate filament marker for neural progenitor cells, which are thought to be, involved in both angiogenesis and neuronal wound repair. The aim of this study was to investigate the expression and distribution of neural progenitor cells in human choroidal neovascularization (CNV) associated with age–related macular degeneration. Methods: CNV membranes were surgically removed from 6 patients with age–related macular degeneration. CNV specimens and normal globes were fixed in formalin, embedded in wax and serially sectioned for histochemical and immunohistochemical evaluation. Immunoreactivity for monoclonal antibodies against nestin was compared to that for cell markers specific for endothelial cells (CD34), RPE (panel cytokeratins), Glia (Glial fibrillar associated protein –GFAP) and macrophages (CD68). Results: Nestin positive cells were predominately found at the ora serrata of normal globes. The cells tended to be both within and superficially on the retinal surface and appear as elongated with filamentous processes. This area of the retina also stained strongly positive for GFAP. Three CNV membranes showed areas containing nestin positive cells. All three of these membranes also showed reactivity for GFAP. Endothelial cells in highly vascularized areas of CNV membranes, as well as cytokeratin and/or CD68–positive cells were not associated with nestin expression. Conclusions: Our results support the hypothesis that neuronal repair may have a role in the submacular wound healing process and cellular pathogenesis of CNV formation in humans. Understanding the cellular mechanisms of CNV formation may provide novel rationales for the development of new pharmacological therapies for CNV.

Keywords: choroid: neovascularization • pathology: human • age-related macular degeneration