Mechanical stimulation effects on functional end effectors in osteoblastic MG-63 cells.
Mechanical stimulation effects on functional end effectors in osteoblastic MG-63 cells.
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DOI：
10.1016/j.jbiomech.2005.04.011
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发表时间：
2006
影响因子：
2.4
通讯作者：
M. Saunders;A. Taylor;C. Du;Z. Zhou;V. Pellegrini;H. Donahue
中科院分区：
文献类型：
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作者：
M. Saunders;A. Taylor;C. Du;Z. Zhou;V. Pellegrini;H. Donahue
NF-κB配体受体激活因子（RANKL）和骨保护素（OPG）参与骨代谢。具体而言，认为这些因子与NF-κB受体激活剂（RANK）的平衡是决定破骨细胞生成速率和骨形成/吸收净结果的关键。虽然公认体内机械负荷影响骨形成/吸收，并且骨细胞对机械负荷的反应性改变与代谢性骨病有关，但体外机械负荷对成骨细胞产生OPG和RANKL的影响尚未得到广泛研究。因此，在本研究中，我们建立了一个体外模型，以负载人成骨细胞，并研究了OPG，RANKL，PGE 2和巨噬细胞集落刺激因子（M-CSF）的水平。我们假设刺激成骨细胞会增加可溶性OPG相对于RANKL的释放，有利于骨形成（和再吸收抑制）事件。为了实现这一点，我们开发了一种小型加载机，通过弯曲，明确的基板变形赋予人工基板上培养的骨细胞。上样2 h和孵育1 h后，收集培养基，并使用ELISA和蛋白质印迹法定量可溶性OPG、RANKL、PGE 2和M-CSF的水平。我们发现，在这个3小时的时间点，相对于RANKL，机械负荷显着增加了可溶性OPG水平。检测到的可溶性和细胞RANKL水平未受到机械刺激的显著影响。与施加的机械刺激相关的OPG相对于RANKL丰度的相对变化表明可溶性OPG：RANKL比率在骨细胞的负荷诱导偶联机制中可能是重要的。
Receptor activator of Nf-κB ligand (RANKL) and osteoprotegerin (OPG) have been implicated in bone metabolism. Specifically, the balance of these factors in conjunction with receptor activator of Nf-κB (RANK) is believed to be key in determining the rate of osteoclastogenesis and the net outcome of bone formation/resorption. While it is well accepted that mechanical loading in vivo affects bone formation/resorption and that alterations in the responsiveness of bone cells to mechanical loading have been implicated in metabolic bone diseases, the effect of in vitro mechanical loading on osteoblastic production of OPG and RANKL has not been extensively studied. Thus, in the current study, we developed an in vitro model to load human osteoblasts and studied levels of OPG, RANKL, PGE2and macrophage colony stimulating factor (M-CSF). We hypothesized that stimulating osteoblastic cells would increase the release of soluble OPG relative to RANKL favoring a bone-forming (and resorption-inhibiting) event. To accomplish this, we developed a small-scale loading machine that imparts via bending, well-defined substrate deformation to bone cells cultured on artificial substrates. Following 2h of loading and a 1h incubation period, media was collected and levels of soluble OPG, RANKL, PGE2and M-CSF were quantified using ELISA and western blotting. We found that mechanical loading significantly increased soluble OPG levels relative to RANKL at this 3h time point. Levels of soluble and cellular RANKL detected were not significantly affected by mechanical stimulation. The relative shift in abundance of OPG over RANKL associated with applied mechanical stimulation suggests the soluble OPG:RANKL ratio may be important in load-induced coupling mechanisms of bone cells.