Wu Yuqiong, Zhang Peng, Dai Qinggang, Fu Runqing, Yang Xiao, Fang Bing, Jiang Lingyong
Center of Craniofacial Orthodontics, Department of Oral and Cranio-Maxillofacial Science, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, P.R. China.
Biomed Rep. 2013 May;1(3):474-478. doi: 10.3892/br.2013.84. Epub 2013 Mar 20.
Mechanical stress plays a crucial role in bone formation and absorption. In previous studies, we verified the osteoblastogenesis of bone mesenchymal stem cells (BMSCs) affected by intermittent traction stretch. However, little is known about the osteoclastogenesis process under mechanical stimulation and its underlying association with osteoblastogenesis. In the present study, we investigated the osteoclastogenesis of BMSCs under this special mechanical stress. BMSCs were subjected to 10% elongation for 1-7 days using a Flexcell Strain Unit and then the mRNA levels of osteoclastic genes were examined. The results indicated time-dependent varying of mRNA levels of the receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in BMSCs at different stretching time points. The ratio of RANKL/OPG increased at the early stage of mechanical stimulation (5 days) and decreased to a low level at a later stage (7 days). Findings of this study may help to understand the correlations between osteoblastogenesis and osteoclasteogenesis when mechanical stretch induces the osteoblastic differentiation of BMSCs.
机械应力在骨形成和吸收过程中起着至关重要的作用。在先前的研究中，我们证实了间歇性拉伸对骨间充质干细胞（BMSCs）成骨分化的影响。然而，关于机械刺激下破骨细胞生成过程及其与成骨分化的潜在关联，我们所知甚少。在本研究中，我们探究了在这种特殊机械应力下BMSCs的破骨细胞生成情况。使用Flexcell拉伸装置对BMSCs施加10%的伸长，持续1 - 7天，然后检测破骨细胞相关基因的mRNA水平。结果表明，在不同拉伸时间点，BMSCs中核因子κB受体活化因子配体（RANKL）和骨保护素（OPG）的mRNA水平呈现出时间依赖性变化。在机械刺激早期（5天），RANKL/OPG比值升高，而在后期（7天）降至较低水平。本研究结果可能有助于理解当机械拉伸诱导BMSCs成骨分化时，成骨分化与破骨分化之间的相关性。
