Calcium response in single osteocytes to locally applied mechanical stimulus: Differences in cell process and cell body
Calcium response in single osteocytes to locally applied mechanical stimulus: Differences in cell process and cell body
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DOI：
10.1016/j.jbiomech.2009.04.034
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发表时间：
2009-08-25
影响因子：
2.4
通讯作者：
Kamioka, Hiroshi
中科院分区：
文献类型：
--
作者：
Adachi, Taiji;Aonuma, Yuki;Kamioka, Hiroshi
据认为，嵌入骨基质中的骨细胞能够感知基质的变形和/或损伤，并将这些机械信号反馈回适应性骨重塑过程。当成骨细胞在骨形成过程中分化为骨细胞时，它们的形态改变为具有许多细长突起的星状形式。这种特征性的细胞形状可能是细胞突起和细胞体之间机械敏感性差异的基础。为了阐明骨细胞对机械刺激的细胞反应机制，我们使用钙成像技术研究了从鸡胚胎中分离的单个骨细胞对定量控制的局部机械刺激的位点依赖性反应。使用玻璃微针对单个骨细胞施加机械刺激，该玻璃微针靶向通过单克隆抗体 OB7.3 修饰而粘附在细胞膜上的微粒。局部变形的应用在刺激点附近引起钙瞬变，并引起钙瞬变的扩散波传播到整个细胞内区域。当应用于细胞过程时，细胞对刺激的反应率比应用于细胞体时更高。此外，细胞体需要大的变形才能诱导钙瞬变，而细胞突起的相对较小的变形就足够了，这表明细胞突起的机械敏感性高于细胞体。这些结果表明，具有细长突起的细胞形状有助于骨细胞的位点依赖性机械敏感性。 (C) 2009 Elsevier Ltd. 保留所有权利。
It is proposed that osteocytes embedded in the bone matrix have the ability to sense deformation and/or damage to the matrix and to feed these mechanical signals back to the adaptive bone remodeling process. When osteoblasts differentiate into osteocytes during the bone formation process, they change their morphology to a stellate form with many slender processes. This characteristic cell shape may underlie the differences in mechanosensitivity between the cell processes and cell body. To elucidate the mechanism of cellular response to mechanical stimulus in osteocytes, we investigated the site-dependent response to quantitatively controlled local mechanical stimulus in single osteocytes isolated from chick embryos, using the technique of calcium imaging. A mechanical stimulus was applied to a single osteocyte using a glass microneedle targeting a microparticle adhered to the cell membrane by modification with a monoclonal antibody OB7.3. Application of the local deformation induced calcium transients in the vicinity of the stimulated point and caused diffusive wave propagation of the calcium transient to the entire intracellular region. The rate of cell response to the stimulus was higher when applied to the cell processes than when applied to the cell body. In addition, a large deformation was necessary at the cell body to induce calcium transients, whereas a relatively small deformation was sufficient at the cell processes, suggesting that the mechanosensitivity of the cell processes was higher than that of the cell body. These results suggest that the cell shape with slender processes contributes to the site-dependent mechanosensitivity in osteocytes. (C) 2009 Elsevier Ltd. All rights reserved.