Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
J Orthop Res. 2011 Jul;29(7):1075-80. doi: 10.1002/jor.21334. Epub 2011 Feb 22.
Whole body vibration (WBV), consisting of a low-magnitude, high-frequency (LMHF) signal, is anabolic to bone in vivo and may act through alteration of the lineage commitment of mesenchymal stromal cells (MSC). We investigated the effect of LMHF vibration on rat bone marrow-derived MSCs (rMSCs) in an in vitro system. We subjected rMSCs to repeated (six) bouts of 1-h vibration at 0.3g and 60 Hz in the presence of osteogenic (OS) induction medium. The OS differentiation of rMSCs under the loaded and non-loaded conditions was assessed by examining cell proliferation, alkaline phosphatase (ALP) activity, mRNA expression of various osteoblast-associated markers [ALP, Runx2, osterix (Osx), collagen type I alpha 1 (COL1A1), bone sialoprotein (BSP), osteopontin (OPN), and osteocalcin (OCN)], and matrix mineralization. LMHF vibration did not enhance the OS differentiation of rMSCs. Surprisingly, the mRNA level of Osx, a transcription factor necessary for osteoblast formation, was decreased, and matrix mineralization was inhibited. Our findings suggest that LMHF vibration may exert its anabolic effects in vivo via mechanosensing of a cell type different from MSCs.
全身振动(WBV)由低幅度、高频(LMHF)信号组成,对体内骨骼具有合成代谢作用,可能通过改变间充质基质细胞(MSC)的谱系定向来发挥作用。我们在体外系统中研究了 LMHF 振动对大鼠骨髓来源的 MSC(rMSC)的影响。我们在存在成骨(OS)诱导培养基的情况下,对 rMSC 进行了六次 1 小时、0.3g 和 60Hz 的重复振动。通过检测细胞增殖、碱性磷酸酶(ALP)活性、各种成骨细胞相关标志物(ALP、Runx2、osterix(Osx)、胶原 I 型α1(COL1A1)、骨涎蛋白(BSP)、骨桥蛋白(OPN)和骨钙素(OCN)的 mRNA 表达)和基质矿化来评估 rMSC 在加载和未加载条件下的 OS 分化。LMHF 振动并未增强 rMSC 的 OS 分化。令人惊讶的是,成骨细胞形成所必需的转录因子 Osx 的 mRNA 水平降低,基质矿化受到抑制。我们的研究结果表明,LMHF 振动可能通过不同于 MSC 的细胞类型的机械感觉在体内发挥其合成代谢作用。