The effects of growth factors on the proliferation and in vitro angiogenesis of human macular inner choroidal endothelial cells

Aim: To investigate the effect of VEGF(165), FGF2, IGF-1, PDGF-AA, PDGF-BB and IL-1 beta on the proliferation and angiogenic tube formation of human macular inner choroidal endothelial cells (ICEC). Methods: The proliferation of human macular ICECs after exposure to the aforementioned growth factors was determined by using both a WST-1 colorimetric assay and a cell-counting technique. The effect of growth factors on ICEC angiogenesis was assessed by sprout formation using a three-dimensional in vitro Matrigel duplex assay. Results: Using both the WST-1 assay and a cell-counting technique, VEGF(165) and FGF2 both significantly increased human macular ICEC proliferation. The effect of equimolar concentrations of VEGF(165) and FGF2 was additive. There was no significant effect for IGF-1, PDGF-AA, PDGF-BB or IL-1 beta on proliferation up to a growth factor concentration of 1000 pmol/l. The angiogenesis assay found a significant effect on sprout formation for VEGF(165) and FGF2. Again, the effect of equimolar concentrations of VEGF(165) and FGF2 was additive. There was no significant effect for IGF-1, PDGF-AA, PDGF-BB or IL-1 beta on sprout formation at 1000 pmol/l. Conclusions: Both VEGF(165) and FGF2 significantly increase human macular ICEC proliferation and sprout formation in an angiogenesis assay. When present together, their effect was additive. IGF-1, PDGF-AA, PDGF-BB and IL-1 beta did not have any significant effect on proliferation or sprout formation in vitro. These results suggest that targeting other growth factors such as FGF2, in addition to VEGF, may be beneficial in the treatment of neovascular age-related macular degeneration.