Serum contains chemoattractants for human retinal pigment epithelial cells

Blood or serum in the vitreous cavity is associated with cellular membrane formation in proliferative vitreoretinopathy and following severe trauma. Retinal pigment epithelial cells (RPE) are important components of these membranes. For RPE cells to effectively spread throughout the vitreous cavity and form contractile membranes, cell migration must occur. We found that fetal bovine serum and human serum increase human RPE cell migration in a dose-dependent manner; fibronectin (FN) caused a dose-dependent increase in RPE cell migration of similar magnitude. This effect was independent of any effect on cell attachment. The RPE cell migration occurred along a gradient from low to high concentrations of FN and thus represents chemotaxis. Serum depleted of FN lost much of its ability to stimulate RPE cell migration. These results demonstrate that serum contains chemoattractants for human RPE cells and that FN accounts for much of this activity.