Opposite effects of bone morphogenetic protein-2 and transforming growth factor-β1 on osteoblast differentiation

BMP-2-induced Runx2 Expression Is Mediated by Dlx5, and TGF-β1 Opposes the BMP-2-induced Osteoblast Differentiation by Suppression of Dlx5 Expression

“…In other words, the Runx2 induction by factors other than BMP is not mediated by Dlx5 (Fig. 2) (10,29,33). However, each suggested different mechanism, especially, in terms of Runx2 involvement in the process.…”

“…On the other hand, Alliston et al (33) suggested that TGF-␤1 inhibits osteoblast differentiation of primary cultured mouse calvarial cells or ROS 17/2.8 cells by repression of Runx2 expression through Smad3 activation. In addition, SpinellaJeagle et al (29) showed that TGF-␤1 did not sensibly modify the increase of Runx2 gene expression mediated by BMP-2, thus demonstrating that the inhibitory effect of TGF-␤1 on osteoblast differentiation and maturation stimulated by BMP-2 was independent of Runx2 gene expression. The latter two reports concerning Runx2 regulation by TGF-␤1 are quite different from our previous reports (4, 10) in which we consistently demonstrated TGF-␤1 stimulated Runx2 expression.…”

“…In contrast, TGF-␤1 was not only unable to induce these markers, but it dramatically inhibited BMP-2-mediated OC gene expression and ALP activity (29). As Dlx5 expression increased with BMP-2-induced osteoblast differentiation, we investigated whether the inhibitory role of osteoblast differentiation by TGF-␤1 was also mediated by the BMPspecific target, Dlx5.…”

Pathophysiological role of enhanced bone marrow adipogenesis in diabetic complications

“…52,53 Shifts in the expression or function of these and other effectors disrupt the homeostatic balance between adipogenic and osteogenic differentiation of MPCs. [54][55][56][57][58][59] While the general consensus is that diabetic hyperglycemia is associated with increased adipogenesis in the marrow, inhibition of fat cell formation and promotion of osteoblastic differentiation following the administration of exogenous glucose has also been reported. 60, 61 Shilpa and colleagues found that culturing 3T3-L1 preadipocytes in extremely high glucose levels of 105 mM resulted in diminished adipogenesis, with downregulation of PPARg and C/EBPa relative to cells cultured in 25 mM glucose concentration.…”

The differential effects of the radioprotectant drugs amifostine and sodium selenite treatment in combination with radiation therapy on constituent bone cells, ewing's sarcoma of bone tumor cells, and rhabdomyosarcoma tumor cells in vitro

“…6 Irradiation effects on mineralization were assessed at 14 days and quantified using a validated colorimetric alizarin red assay. 6 After fixation with 70% ethanol cells were stained using 40 mM alizarin red S stain (pH 4.2, Sigma) and decolorized using 10% cetylpyridinium chloride in 10 mM NaPO 4 (pH 7.0). The resulting alizarin/cetylpyridinium chloride solution was analyzed at 570 nm and compared to a standard curve of alizarin concentrations in cetylpyridinium chloride.…”