[Mitogenesis of platelet-derived growth factors to human osteoblasts modulated by basic fibroblast growth factor].
OBJECTIVE
To investigate the mechanism by which basic fibroblast growth factor modulates the mitogenesis of platelet-derived growth factor to human osteoblasts.


METHODS
The osteoblasts isolated from human fetal calvaria were incubated with PDGF-AB (100 ng/ml) or bFGF(10 ng/ml) combined with PDGF-AB (100 ng/ml); the growth curve was plotted. The(3)H-TdR incorporation of the osteoblasts was measured after the cells were incubated with different combination of bFGF and PDGF-AA or PDGF-BB. After incubated with bFGF (10 ng/ml) for 24 hours, the number of PDGFR-alpha and PDGFR-beta on the membrane of the osteoblasts was detected by fluoroimmunoassay.


RESULTS
Four days after PDGF-AB added into the medium, the population of the osteoblasts was larger than that of the control (P < 0.05). The number of the osteoblasts incubated with PDGF-AB (12.1 x 10(4)) was 1.8 times as large as the control (6.8 x 10(4)) in the 10th day (P < 0.05), and that of the osteoblasts incubated with both bFGF and PDGF-AB increased more quickly than the cells only incubated with PDGF-AB. The incorporation of (3)H-TdR into the osteoblasts cultured with bFGF combined with PDGF-AA (533.6 +/- 13.1) was more than that cultured only with PDGF-AA (435.4 +/- 14.8, P < 0.01), so was the incorporation of (3)H-TdR of those cells cultured with bFGF and then PDGF-AA (633.8 +/- 51.5). bFGF up-regulated PDGFR-alpha and down-regulated PDGFR-beta on the surface of the human osteoblasts.


CONCLUSIONS
bFGF elevates the mitogenesis of PDGF-AA or -AB to human osteoblasts by up-regulating PDGFR-alpha.
Chen
J
J
Department of Orthopeadic Surgery, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
Yang
D
D
Jing
Z
Z
Wu
D
D
Ding
H
H
Jin
D
D
D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004357:Drug Synergism; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006801:Humans; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism
D010982:Platelet-Derived Growth Factor; C095477:platelet-derived growth factor AB; D016222:Fibroblast Growth Factor 2; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta