PROLIFERATIVE RESPONSE OF CULTURED HUMAN TENONS CAPSULE FIBROBLASTS TO PLATELET-DERIVED GROWTH-FACTOR ISOFORMS

Background: Although platelet-derived growth factor (PDGF) has been th ought to be critical in the wound-healing response of Tenon's capsule fibroblasts after glaucoma filtration surgery, no information is curre ntly available con cerning the proliferative effect of PDGF isoforms o n this cell type. The aim of the present study was to evaluate the pro liferative effect of PDGF-AB heterodimer and PDGF-AA and -BB homodimer s on cultured human Tenon's capsule fibroblasts. Methods: Human Tenon' s capsule fibroblasts, cultured under serum-free conditions, were stim ulated with PDGF-AA, -AB and -BE isoforms in concentrations ranging fr om 1 to 100 ng/ml. Cell numbers were determined on days 1, 3, 5 and 7, using a cell counter. Results: Addition of PDGF-AB and -BE led to a d ose-dependent increase in cell proliferation. A maximal response (79.9 % over control) was obtained after 7 days with 30 ng/ml of PDGF-BB, wi th an EC50 of 8.9 ng/ml. The maximal increase in cell proliferation ca used by PDGF-AB (30 ng/ml) was 54.9%, with an EC50 of 12.5 ng/ml. Stim ulation with PDGF-AA revealed a significant effect only with con centr ations higher than 30 ng/ml. Conclusion: Our results indicate that PDG F-AB and -BB isoforms are potent stimulators of proliferation of human Tenon's capsule fibroblasts, suggesting that PDGF-AB and -BE isoforms play an important role in the wound-healing response after glaucoma f iltration surgery.