Homologous serum-stimulated fibronectin synthesis in human retinal pigmented epithelial cells

Purpose: Fibronectin expression has been recorded in subretinal membranes from patients with proliferative vitreoretinopathy (PVR). Retinal pigmented epithelial (RPE) cells are a major cellular component of PVR membranes and synthesize fibronectin. We investigated the effects of human serum (as a model of vascular leakage in vivo) on the expression of fibronectin by cultured human RPE cells and compared the responses to those stimulated by fetal bovine serum (FBS). Methods: Human RPE cells were incubated in M199 with 1, 10 and 40% human adult serum or FBS for 72 h. Results: Retinal pigmented epithelial cells expressed maximum extracellular matrix fibronectin when exposed to 40% human serum using immunohistochemistry. Using ELISA to quantify fibronectin, 10 and 40% human serum significantly increased the total fibronectin (P < 0.01; n = 4), whereas FBS did not affect fibronectin expression. Conclusions: The results show that human serum contains substances stimulating fibronectin synthesis in human RPE cells.