A model for strain amplification in the actin cytoskeleton of osteocytes due to fluid drag on pericellular matrix
A model for strain amplification in the actin cytoskeleton of osteocytes due to fluid drag on pericellular matrix
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DOI：
10.1016/s0021-9290(01)00107-5
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发表时间：
2001-11-01
影响因子：
2.4
通讯作者：
Weinbaum, S
中科院分区：
文献类型：
--
作者：
You, LD;Cowin, SC;Weinbaum, S
提出了一种模型，该模型为骨生理学中的基本悖论提供了解决方案，即，施加到整个骨的应变（即，组织水平的菌株）比在变形细胞培养物中引起骨信号传导所必需的菌株（1- 10%）小得多（0.04- 0.3%）（Rubin和Lanyon，J.BoneJointSurg.66A（1984）397-410; Fritton等，J. Biomech. 33（2000）317-325）。流体拖曳力对细胞周围基质（PM），其耦合到细胞内肌动蛋白细胞骨架（IAC）和应变放大，从这种耦合的结果的影响进行检查的第一次。该模型导致两个预测，这可能从根本上改变现有的观点。首先，对于1-20 MPa的载荷范围和1-20 Hz的频率范围，确实有可能在骨中产生比正常组织水平应变（0.04- 0.3%）大100倍的细胞水平应变。因此，由于负载导致的细胞过程膜中的应变可以与在细胞培养研究中测量的体外应变具有相同的量级，在细胞培养研究中观察到拉伸的弹性基底上的细胞的细胞内生化反应。第二，它表明，在任何细胞系统中，细胞受到流体流动和拴系到更刚性的支持结构，由于拴系纤维上的拖曳力，细胞的张力可能比细胞膜上的流体剪切力大许多倍。(C)2001爱思唯尔科技有限公司版权所有。
A model is presented that provides a resolution to a fundamental paradox in bone physiology, namely, that the strains applied to whole bone (i.e., tissue level strains) are much smaller (0.04-0.3 percent) than the strains (1-10 percent) that are necessary to cause bone signaling in deformed cell cultures (Rubin and Lanyon, J. Bone Joint Surg. 66A (1984) 397-410; Fritton et al., J. Biomech. 33 (2000) 317-325). The effect of fluid drag forces on the pericellular matrix (PM), its coupling to the intracellular actin cytoskeleton (IAC) and the strain amplification that results from this coupling are examined for the first time. The model leads to two predictions, which could fundamentally change existing views. First, for the loading range 1-20 MPa and frequency range 1-20 Hz, it is, indeed, possible to produce cellular level strains in bone that are up to 100 fold greater than normal tissue level strains (0.04-0.3 percent). Thus, the strain in the cell process membrane due to the loading can be of the same order as the in vitro strains measured in cell culture studies where intracellular biochemical responses are observed for cells on stretched elastic substrates. Second, it demonstrates that in any cellular system, where cells are subject to fluid flow and tethered to more rigid supporting structures, the tensile forces do the cell due to the drag forces on the tethering fibers may be many times greater than the fluid shear force on the cell membrane. (C) 2001 Elsevier Science Ltd. All rights reserved.