help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lau, K. H.
Right arrow Articles by Baylink, D. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lau, K. H.
Right arrow Articles by Baylink, D. J.

Endocrinology, Vol 123, 2858-2867, Copyright © 1988 by Endocrine Society

ARTICLES

Vanadate stimulates bone cell proliferation and bone collagen synthesis in vitro

KH Lau, H Tanimoto and DJ Baylink
Department of Medicine, Loma Linda University, California.

We recently proposed a hypothesis for the molecular mechanism of the osteogenic action of fluoride in which it stimulates osteoblast proliferation via the inhibition of an osteoblastic acid phosphatase- like phosphotyrosyl protein phosphatase activity. To test this hypothesis, we investigated whether orthovanadate, a known phosphotyrosyl protein phosphatase inhibitor, would mimic fluoride in the stimulation of bone cell proliferation and bone collagen synthesis in vitro. Orthovanadate inhibited the osteoblastic acid phosphatase activity and stimulated bone cell proliferation at the same low concentrations (i.e. 5-15 microM). At the mitogenic doses, orthovanadate also showed a dose-dependent increase in alkaline phosphatase (a marker of mature osteoblasts) in cultured calvarial cells and stimulated bone collagen synthesis, as measured by the incorporation of [3H]proline and the conversion into [3H] hydroxyproline in organ calvaria cultures. Therefore, orthovanadate stimulated bone formation by increasing the number of mature osteoblasts mediated via stimulation of cell proliferation and differentiation. Orthovanadate was dependent on the presence of a mitogen in cell medium for its mitogenic action in vitro and synergistically potentiated the mitogenic actions on osteoblasts of those growth factors, i.e. insulin, epidermal growth factor, insulin- like growth factor I, and skeletal growth factor, whose mitogenic action involved tyrosyl protein phosphorylation. However, the interaction between orthovanadate and basic fibroblast growth factor, a growth factor that does not appear to involve tyrosyl protein phosphorylation, on bone cell proliferation was additive. In summary, these data are consistent with the hypothesis that inhibition of the osteoblastic phosphotyrosyl protein phosphatases can prolong and/or potentiate the mitogenic actions of growth factors, and thereby stimulates cell proliferation.


This article has been cited by other articles:


Home page
 EndocrinologyHome page
Y. Engelbrecht, H. de Wet, K. Horsch, C. R. Langeveldt, F. S. Hough, and P. A. Hulley
Glucocorticoids Induce Rapid Up-Regulation of Mitogen-Activated Protein Kinase Phosphatase-1 and Dephosphorylation of Extracellular Signal-Regulated Kinase and Impair Proliferation in Human and Mouse Osteoblast Cell Lines
Endocrinology, February 1, 2003; 144(2): 412 - 422.
[Abstract] [Full Text] [PDF]

Home page
 J. Clin. Endocrinol. Metab.Home page
L.-W. Wu, H. K. Yoon, D. J. Baylink, L. M. Graves, and K.-H. W. Lau
Fluoride at Mitogenic Doses Induces a Sustained Activation of p44mapk, but Not p42mapk, in Human TE85 Osteosarcoma Cells
J. Clin. Endocrinol. Metab., April 1, 1997; 82(4): 1126 - 1135.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1988 by The Endocrine Society