Autocrine regulation of bovine retinal capillary endothelial cell (BREC) proliferation by BREC-derived basic fibroblast growth factor.

Fibroblast growth factors (FGFs) are mitogenic for bovine retinal capillary endothelial cells (BREC) seeded at a low density. Seeding BREC cells at a high density greatly reduces their requirement for basic FGF (bFGF) in order to proliferate actively. We show here that monolayers of BREC cells synthesize and release into the culture medium a growth factor, which on the basis of biological activity, heparin affinity, immuno-cross reactivity with anti-bFGF antibodies and mRNA analysis, has been identified as basic fibroblast growth factor. These data indicate that BREC cells are able to synthesize and release bFGF, which can act as a promoting-growth factor for these cells by a para- and/or autocrine mechanism. We suggest thus, that this para- and/or autocrine mechanism involving bFGF may play a key role in preretinal neovascularization, particularly in diabetic patients presenting a proliferative retinopathy.