Modulation of transforming growth factor beta to platelet-derived growth factor receptor-alpha of human osteoblasts.
OBJECTIVE
To investigate the mechanism and the significance of TGF beta in modulating the expression of Platelet-Derived Growth Factor Receptor-alpha (PDGFR-alpha) in human osteoblasts.


METHODS
The osteoblasts were isolated from human fetal calvaria. The percentage of cell increase (PCI) in every 4 hours was calculated to demonstrate the proliferation of osteoblasts affected by PDGF-AA and TGF beta. The osteoblasts were cultured with TGF beta for 24 hours and with PDGF-AA for another 24 hours, and the cells proliferation was shown by PCI too. The osteoblasts were cultured with TGF beta for 24 h, and the PDGFR-alpha of the cells were measured by immunofluorescent analysis.


RESULTS
PCI was increased by 48.2% and 22.4% after PDGF-AA and TGF beta were added into the medium for 24 hours respectively (P < 0.05), and PCI decreased after the removal of the two cytokines. Preincubated with TGF beta for 24 hours and then stimulated with PDGF-AA, PCI grew slowly. TGF beta downregulated the expression of the PDGFR-alpha.


CONCLUSIONS
TGF beta can downregulate the mitogenesis of PDGF-AA by lowering the number of PDGFR-alpha.
Yang
D
D
Department of Orthopeadic Surgery, Nan Fang Hospital, First Military Medical University, Guangzhou 510515, China.
Jin
D
D
Chen
J
J
Jing
Z
Z
Wu
D
D
D002455:Cell Division; D002478:Cells, Cultured; D006801:Humans; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000096:biosynthesis*; D016212:Transforming Growth Factor beta / Q000502:physiology*
D016212:Transforming Growth Factor beta; D020796:Receptor, Platelet-Derived Growth Factor alpha