The association of platelet-derived growth factor (PDGF) receptor tyrosine phosphorylation to mitogenic response of human osteoblastic cells in vitro.
OBJECTIVE
The purpose of this study was to make clear the relationship of human osteoblastic cell growth, induced by platelet-derived growth factor (PDGF), to PDGF receptor tyrosine phosphorylation.


METHODS
Osteoblastic cells derived from human maxilla were cultured with human PDGF. The cell growth was evaluated by cell number and DNA synthesis. PDGF receptor tyrosine phosphorylation was detected by immunoblot analysis using anti-PDGF receptor alpha, beta subunits and anti-phosphotyrosine antibodies. Genistein, a tyrosine kinase inhibitor, was added to the culture to investigate the effect on osteoblastic cell growth and PDGF receptor tyrosine phosphorylation induced by PDGF.


CONCLUSIONS
PDGF stimulated the proliferation of human osteoblastic cells and this effect was synergetic with serum stimulation. DNA synthesis of osteoblastic cells was elevated by PDGF in a dose dependent manner at the minimum concentration of 1 ng ml-1. PDGF also induced PDGF receptor tyrosine phosphorylation within 1 min on osteoblastic cells, and tyrosine phosphorylation occurred on PDGF receptor subunits alpha and beta. Genistein inhibited cell growth and receptor tyrosine phosphorylation, which was induced by PDGF on these cells. In conclusion, human osteoblastic cell growth induced by PDGF is shown to relate to tyrosine kinase of PDGF receptors.
Nakanishi
H
H
First Department of Oral and Maxillofacial Surgery, School of Dentistry, Tokushima University, Japan.
Yamanouchi
K
K
Gotoh
Y
Y
Nagayama
M
M
D000077214:Becaplermin; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D015151:Immunoblotting; D008437:Maxilla / Q000166:cytology; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology* / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020574:Proto-Oncogene Proteins c-sis; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism
D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins; D000077214:Becaplermin; D014443:Tyrosine; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D017479:Receptors, Platelet-Derived Growth Factor