PDGF-BB Stimulate Gliosis in a Mouse Organ Culture Model of PVR

Abstract

Abstract: : Purpose:Increased levels of growth factors have been identified in the vitreous of patients with proliferative vitreoretinopathy (PVR). The aim of this study is to determine the effects of growth factors on retinal contraction in a new experimental mouse model. Method:One hundred twenty eyes from C57BL/6J mice and 8 eyes from transgenic mice expressing green fluorescent protein (GFP) under the control of the glial fibrillary acidic protein (GFAP) promoter were used to obtain retinal explant organ cultures. Explants were exposed to growth factors and retinal appearance was photographed on days 1,4 and 7. Then the organ cultures were histologically examined for evidence of retinal contraction. The cultures of the GFP transgenic mice retinas were observed periodically using confocal laser microscopy. Proliferation of cells in the organ culture of GFP transgenic mice was examined using bromodeoxyuridine (BrdU) incorporation. Results:Three types of changes in appearance of the retina (rolled-up retinal edge, retinal fold and contraction) were seen. In the control group the incidence of rolled-up-retina was 21% and retinal fold was 12.5%. The incidence of both types of changes was increased most prominently by PDGF-BB(p=0.02). Retinal contraction rate (% reduction of retinal area) was highest in PDGF-BB group. GFP-positive cells (glia) could be observed along the rolled-up retinal edge and retinal fold in the transgenic mice retinas. Almost all of the BrdU stained proliferating cells were GFP positive. Conclusion: PDGF–BB play an important role in promotion of glial cell proliferation and associated retinal contraction in an in vitro model of PVR.

Keywords: animal model • proliferative vitreoretinopathy • transgenics/knock-outs