Effects Of PDGF-BB And BFGF On Proliferation And ALP Activity In Human Periodontal Ligament Cells: An In Vitro Study

Objective: The cytokines have an effect of proliferation and other characters on periodontal cells. This series of experiments aimed at evaluating the effects of platelet derived growth factor-BB, PDGF-BB and basic fibroblast growth factor, bFGF on the proliferation and alkaline phosphatase, ALP, activity of periodontal ligament cells, PDLC. And the regenerative reconstruction effect of the two cytokines on human periodontal tissues was detected.Methods: We cultured PDLC from the third generation in vitro. The cells of 4 to 8 generations were divided into control group and experimental groups. The cells of experimental groups were treated with PDGF-BB (0.1,1,10,100ng/ml) and bFGF (1,10,50,100ng/ml). To evaluate proliferation: At the third day, we detected the cell proliferation with MTT method, and the maximum and the minimum effective concentration of two cytokines were detected. And we treated the PDLCs with the maximum and the minimum effective concentration of two cytokines separately or jointly. And the cell proliferation was detected with MTT method at the 1, 3, 6, 9 day of treating. To evaluate ALP activity: We treated the cells with maximum and minimum concentrations of two cytokines separately or jointly. At the third day, we spallated all the groups, and All groups were divided into lysate group and cultured group. The ALP activity was detected with ALP agent box (Indicated with OD value).Results: Cell proliferation: At the third day, the maximum and minimum effective concentration of PDGF-BB is 10ng/ml and 1ng/ml, the maximum and minimum effective concentration of bFGF is 50ng/ml and 1ng/ml. The peak value of separated use of PDGF-BB and the jointly use of two cytokines were at the ninth day, while of the separated use of bFGF was at the sixth day. ALP activity: At the third day, the OD values of cell lysate group and cultured group treated by PDGF-BB peaked at 0.1ng/ml and 1ng/ml. The OD values of cell lysate group and cultured group treated by bFGF peaked at 1ng/ml and 10ng/ml. The OD value of PDGF-BB (10ng/ml)+bFGF(50ng/ml) or PDGF-BB(1ng/ml)+bFGF(1ng/ml) were significantly higher than the control group.Conclusion:Both the PDGF-BB and bFGF have significant effect on the proliferation of PDLCs. And the combination of two cytokines has synergistic action. It shows a time-concentration dependent relationship within 1,3,6,9 days. The two factors have a significant effect on the ALP activity either. However, the maximum effective concentration is small in dosage and they didn't show a synergistic action on ALP activity. The effect of two factors on proliferation and ALP activity were different. It may relate with their structures, interactive styles with PDLC and the receptors of two factors on the PDLC.