Photoreceptor-specific expression of platelet-derived growth factor-B results in traction retinal detachment

Expression of platelet-derived growth factor (PDGF)A and PDGF-B is increase d in patients with proliferative retinopathies in which traction retinal de tachments occur. Previous studies have demonstrated that increased expressi on of PDGF-A in the retina of transgenic mice results in retinal gliosis du e to proliferation of astrocytes with different retinal phenotypes based on the time of onset and location of the PDGF-A production. hi this study, we investigated the effects of PDGF-B in the retina using gain-of-function tr ansgenic mice that express PDGF-B in photoreceptors. These mice show prolif eration of astrocytes, pericytes, and, to a lesser extent, endothelial cell s, resulting in ectopic cells on the surface and extending into the retina. The sheets of cells exert traction on the retina resulting in traction ret inal detachments similar to those seen in humans with proliferative retinop athies. These studies suggest that PDGF-B has more dramatic effects in the retina than PDGF-A, because it acts on additional cell types, in particular on pericytes, which have a highly developed contractile apparatus. These s tudies in the retina suggest a means that could be used in. other tissues t hroughout the body to achieve graded PDGF effects. They also provide a new model of traction retinal detachment that can be used to investigate new tr eatments for patients with proliferative retinopathies.