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

机械载荷在包括鳞骨和下颌骨在内的全骨形成和重塑过程中对骨的生长起着重要的作用。为了阐明机械载荷对骨细胞生长和形成的影响，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旋转（GVC），它被认为是通过分散负荷来抵消重力对培养细胞和植物和动物胚胎的影响。另一种是离心培养，在培养细胞上连续施加高重力。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，我们使用阿菲霉素处理的同步培养细胞进行了流式细胞术分析。结果表明，细胞周期在S期进展中受到抑制，并表现出从G_1期向S期转移的延迟。另一方面，MC3T3-E1细胞在离心产生的机械负荷下培养时，增殖率增加。超重力培养48小时后，30 G和60 G下细胞生长增量分别约为13%和26%。在这种情况下，与对照组相比，S相进程固定了约10%。此外，在不同的机械负荷下，细胞的一些生长相关基因表达也发生了变化。细胞在机械负荷下培养时，c-fos和c-myc表达短暂升高。另一方面，GVC作用下c-fos表达降低。c-jun和p53以及控制基因G3PDH和β -actin的表达无差异。对机械载荷对培养成骨细胞的影响进行一系列的研究，将有助于我们厘清机械载荷与骨形成和骨重塑的关系。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