Orcel P, Bielakoff J, De Vernejoul M C
INSERM U18, Hôpital Lariboisière, Paris, France.
J Cell Physiol. 1990 Feb;142(2):293-8. doi: 10.1002/jcp.1041420211.
Transforming growth factor-beta (TGF-beta) modulates growth and differentiation in many cell types and is abundant in bone matrix. We recently showed that human cord blood monocytes cultured in the presence of 1,25(OH)2D3 acquire some features of osteoclast precursors. Since TGF-beta has been shown to influence bone resorption in organ culture, we have studied the effect of TGF-beta (1-1,000 pg/ml) on cord blood monocyte cultures. These cells were cultured on plastic substrate during 3 weeks in the presence of 20% horse serum and 10(-9) M 1,25(OH)2D3. TGF-beta, from a concentration of 10 pg/ml in the culture medium, decreased in a dose dependent manner the formation of multinucleated cells. At a concentration of TGF-beta of 1 ng/ml, the multinucleated cells were reduced to 2.1% +/- 0.3%, compared to 19.3% +/- 1.5% in control cultures. TGF-beta inhibited in a dose-dependent manner the proliferation of cord blood monocytes as assessed by 3H-thymidine incorporation at 7 and 14 days of culture. The fusion index was also decreased by 3 weeks of treatment with TGF-beta. Indomethacin did not reverse the inhibitory effects of TGF-beta. The expression of the osteoclastic phenotype was assessed using two different antibodies: 23C6, a monoclonal antibody directed against the vitronectin receptor, which is highly expressed by osteoclasts but not by adult monocytes, and an antibody to HLA-DR, which is not present on osteoclast. TGF-beta decreased the expression of HLA-DR and increased in a dose-dependent manner the proportion of 23C6-labeled cells; these results suggest that TGF-beta could modulate a differentiation effect to the osteoclastic phenotype. However, when cord blood monocytes were cultured on devitalized rat calvariae prelabeled with 45Ca, TGF-beta did not induce any 45Ca release from bone cultured with monocytes, suggesting that full osteoclastic differentiation was not achieved. These results emphasize the complex role of TGF-beta in the local regulation of bone cell differentiation and in bone remodeling.
转化生长因子-β（TGF-β）可调节多种细胞类型的生长和分化，且在骨基质中含量丰富。我们最近发现，在1,25(OH)₂D₃存在的情况下培养的人脐血单核细胞具有破骨细胞前体的一些特征。由于已证明TGF-β会影响器官培养中的骨吸收，我们研究了TGF-β（1 - 1000 pg/ml）对脐血单核细胞培养物的影响。这些细胞在含有20%马血清和10⁻⁹ M 1,25(OH)₂D₃的条件下，在塑料基质上培养3周。培养基中TGF-β浓度从10 pg/ml起，以剂量依赖性方式减少多核细胞的形成。在TGF-β浓度为1 ng/ml时，多核细胞减少至2.1%±0.3%，而对照培养物中为19.3%±1.5%。通过培养7天和14天时的³H - 胸腺嘧啶核苷掺入评估，TGF-β以剂量依赖性方式抑制脐血单核细胞的增殖。用TGF-β处理3周后融合指数也降低。吲哚美辛不能逆转TGF-β的抑制作用。使用两种不同抗体评估破骨细胞表型的表达：23C6，一种针对玻连蛋白受体的单克隆抗体，破骨细胞高度表达而成年单核细胞不表达；以及一种针对HLA - DR的抗体，破骨细胞上不存在该抗体。TGF-β降低HLA - DR的表达，并以剂量依赖性方式增加23C6标记细胞的比例；这些结果表明TGF-β可能调节向破骨细胞表型的分化作用。然而，当脐血单核细胞在预先用⁴⁵Ca标记的失活大鼠颅骨上培养时，TGF-β并未诱导与单核细胞一起培养的骨释放任何⁴⁵Ca，这表明未实现完全的破骨细胞分化。这些结果强调了TGF-β在骨细胞分化的局部调节和骨重塑中的复杂作用。
