EFFECT OF GROWTH FACTORS ON THE MIGRATION OF RPE CELLS IN VITRO
J. Amann, C. Kaven, C.W. Spraul, G.K. Lang, G.E. Lang
Retinal pigment epithelial (RPE) cells play an important role in proliferative vitreoretinopathy (PVR). The aim of this study was to study the effect of IGF-1, PDGF, EGF, aFGF, bFGF and TGFß on the migration of bovine RPE cells in vitro.
Methods. Bovine RPE cells (2x10)4 were cultured in 34 mm 6-well-plates until they reached confluence. Proliferation was inhibited with mitomycin C [10µg/ml]. Half of each well was denuded with a cell scraper. The cultures were then observed in the presence of IGF-1, PDGF, EGF, aFGF, bFGF and TGFß [10µg/ml] or DMEM +5% FCS (control media) alone after 20 hours. Migration was assessed by counting the number of cells in the denuded zone (number/microscopic field). Counts were made in triplicate for each well, assays were performed in duplicate and each assay was repeated three times. The results were statistically analyzed using the Wilcoxon-Rank-Test.
Results. Exposure of RPE cells to IGF-1, PDGF, EGF, aFGF and bFGF resulted in a significantly higher RPE cell migration compared to control media (DMEM + 5% FCS) (p=0.003). PDGF (50 cells/microscopic field) was most potent among the growth factors tested, followed by bFGF (48.9 cells/microscopic field), aFGF (43.7 cells/microscopic field), IGF-l (39.8 cells/microscopic field) and EGF (39.2 cells/microscopic field). The ratio of. potencies of the growth factor PDGF: bFGF: aFGF: IGF-1: EGF in stimulating cell migration is 1: 0.97: 0.87; 0.79: 0.78. The level of RPE cell migration was not significantly different in the presence of TGFß (19.9 cells/microscopic field) compared to control media (16.0 cells/microscopic field) (p=0.15).
Conclusion. The data suggest that there is a positive effect of IGF-1, PDGF, EGF, aFGF, bFGF on RPE cell migration. PDGF is most stimulating and may play an important role in mediating RPE cell migration.
University of Ulm, Department of Ophthalmology, Germany