To determine whether the inhibition of human osteoblast growth mediated by 1α,25-dihydroxyvitamin D3 (1α,25(OH)D3) occurs as a result of changes in transforming growth factor (TGF) and TGF receptor synthesis, we examined the effects of 1α,25(OH)2D3 on the synthesis of TGFβ and TGF-β receptors. Treatment with 1α,25(OH)2D3, but not vehicle, increased TGF-β2 concentrations in human osteoblast cell supernantants in a dose- and time-dependent manner. The increase in TGF-β2 concentrations was associated with an inhibition of osteoblast cell growth; antibodies directed against transforming growth factor β partially blocked the inhibition of cellular growth mediated by 1α,25(OH)2D3. TGF-β2 gene transcription and TGF-β2 mRNA concentrations were increased in 1α,25(OH)D3 but not in vehicle-treated cells. 1α,25(OH)2D3 increased TGF-β type I and type II receptor mRNA levels in osteoblasts. Increased expression of TGF-β2 and TGF-β receptors by 1α,25(OH)2D3 might account for the inhibition of human osteoblast growth seen following 1α,25(OH)2D3 treatment.
|Original language||English (US)|
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Oct 29 1997|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology