Integrin-α5 Mediates Epidermal Growth Factor-Induced Retinal Pigment Epithelial Cell Proliferation and Migration

Abstract
Proliferation and migration of retinal pigment epithelial (RPE) cells play a crucial role in proliferative vitreoretinopathy (PVR)-related pathology. Cytokines, including EGF, can result in RPE cell activation and cause PVR. In this study, integrin-α5 expression was first studied in PVR membranes by immunofluorescence. Then the effect of EGF on integrin-α5 expression was determined by flow cytometry, Western blot analysis and the reverse-transcription polymerase chain reaction (RT-PCR) in the ARPE-19 cell line. Proliferation and migration of ARPE-19 cells were measured by the methylthiazolyldiphenyl-tetrazolium bromide and Boyden chamber assays. We found that a higher level integrin-α5 was present at the RPE cell surface in PVR compared with normal retina. EGF could dose dependently increase integrin-α5 mRNA and protein levels in vitro. EGF promoted ARPE-19 cell proliferation and migration. Neutralizing integrin-α5 by specific anti-integrin-α5 antibody abolished most of the effects of EGF. The study provided evidence that EGF might influence PVR by promoting integrin-α5 expression and subsequent proliferation and migration of RPE.