Effects of the Mechanical Loading on the Proliferation and Differentiation of Osteoblast-Derived Culture Cell.

在包括鳞骨和下颌骨在内的整个骨的形成和重塑过程中，机械载荷对骨的生长起着重要的作用。为了阐明机械载荷对细胞生长和骨形成的影响，我们分析了成骨细胞来源的MC3T3-EL细胞在不同机械载荷下的反应性。一种是重力矢量平均回旋(GVC)，它被认为是通过分散负荷来抵消重力对培养细胞以及动植物胚胎的影响。另一种是离心法，对培养的细胞施加持续的高重力。我们已经报道了成骨细胞来源的MC3T3-E1细胞在GVC下培养时，其增殖率受到抑制，与对照细胞相比，抑制率最高可达65%以上。在本研究中，我们使用APHIDICOIN处理的同步培养细胞进行了流式细胞术分析。结果是，它是…版本进一步研究表明，细胞周期在S期受到抑制，细胞从G_1期向S期的转移也出现延迟。另一方面，MC3T3-E1细胞在离心力作用下培养，细胞增殖率增加。超重培养48h后，细胞生长率在30G时约为13%，60G时约为26%。在这种情况下，与对照组相比，S期进展快约10%。此外，在不同的机械载荷下，细胞生长相关基因的表达也发生了变化。C-fos和c-myc的表达在机械负荷作用下一过性增加。而c-fos在GVC下表达降低，而c-jun、P53和对照基因G3PDH、β-actin的表达无明显差异。对机械载荷对培养的成骨细胞的影响进行一系列的研究，对于弄清机械载荷与骨形成和改建的关系具有重要意义。较少

Mechanical load play an important role on the bone growth during the formation and remodeling of the whole bone including scaletal and mandiblar bones. To clarify the effects of mechanical load on the cells growth and formation of bone, we analyzed the reactivity of osteoblast-derived cells, MC3T3-El cells, under some different kind of mechanical loads. One is gravitational vector-averaged clinorotation (GVC) which was considered to be canceled out the gravity effect on cultured cells as well as plants and animal embryos by diffusing the load. Another is centrifugation culture by which continuous high gravity was loaded on the cultured cells.We already reported that the proliferation rate of osteoblast-derived MC3T3-E1 cells was suppressed when they cultured under the GVC.The suppression rate was maximally over 65% compared to the control cells. In the present study, we performed a flow cytometric analysis using aphidicolin-treated synchronous cultured cells. As the results, it was rev … More ealed that the cell cycle was suppressed at the S phase progression and also showed a delay on the transfers from G_1 phase to S phase. On the other hand, the proliferation rate was increased when the MC3T3-E1 cells were cultured under the mechanical load produced by the centrifugation. The rate of increments of cell growth cultured under hyper gravity after 48 hr was about 13% at 30 G and about 26% at 60 G,respectively. In this case, the S phase progression was fastened about 10% compared to the control. Moreover, some of cell growth-related gene expressions were changed when they cultured under the different mechanical loads. The c-fos and c-myc expressions were transitory increased when the cell was cultured under the mechanical load. On the other hand, c-fos expression was decreased under the GVC.No difference was observed on the expression of c-jun and p53 as well as the control genes, G3PDH and beta-actin. It is important to make a series of the studies on the effect of mechanical load to the cultured osteoblasts and to be considered that it will lead us to be clarify the relationship between the mechanical load and the bone formation and remodeling. Less