Abstract
Abstract: :
Purpose: To characterize the cellular composition of neovascular membranes from advanced retinopathy of prematurity ROP. To compare the expression of neuronal, retinal and vascular markers with those of mature human retina. Methods: Neovascular membranes collected from patients with advanced stage retinopathy of prematurity (stages 4 and 5 ROP) were prepared for frozen sectioning and fluorescent immunohistochemistry, or subjected to collagenase digestion for establishing cell cultures. RT–PCR was performed on both neovascular membranes and cultured cells to determine the expression of poorly differentiated neuronal (nestin, CD133), mature neuronal (MAP 5, NF–200), glial (GFAP), and retinal elements (PKC, opsin and recoverin), and endothelial markers including immature (CD133, Tal–1) and mature elements (CD34, CD31, VEGFR–2, HGFR). Results were compared with cDNA prepared from mature retina. Results: Neovascular membranes from advanced ROP contain both neuronal and vascular compartments within a glial framework. Marker analysis of these membranes and their cultured cells revealed expression of premature (nestin, CD133) and mature neuronal (expressing NeuN, MAP5 and NF–200), glial (GFAP) and retinal elements (expressing opsin, recoverin and PKC), similar to mature retinal tissue. Additionally, RT–PCR analysis of marker expression from both advanced ROP and mature retina suggests similar expression of neuronal and retinal markers. Conclusions: The cellular composition and marker expression of neovascular membranes from advanced ROP indicates homology with mature retinal tissue. Since most retinal elements such as photoreceptor–like and bipolar–like cells are represented within these neovascular membranes, their cultured cells could be propagated and used as a future source for autologous retinal transplantation.
Keywords: retinopathy of prematurity • retinal neovascularization • transplantation