On the electrophysiological response of bone cells using a Stokesian fluid stimulus probe for delivery of quantifiable localized picoNewton level forces.
On the electrophysiological response of bone cells using a Stokesian fluid stimulus probe for delivery of quantifiable localized picoNewton level forces.
复制标题
使用斯托克斯流体刺激探针传递可量化的局部皮牛顿级力，研究骨细胞的电生理反应。
DOI：
10.1016/j.jbiomech.2011.03.034
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发表时间：
2011
影响因子：
2.4
通讯作者：
Weinbaum,Sheldon
中科院分区：
文献类型：
--
作者：
Wu,Danielle;Ganatos,Peter;Spray,DavidC;Weinbaum,Sheldon
斯托克斯流体刺激探针 (SFSP) 能够提供可量化的 pN 级水动力，用于在不接触细胞或其基质的情况下区分骨细胞样 MLO-Y4 细胞的细胞过程和细胞体的电生理反应。流体动力学扰动是一种短暂的（100 毫秒）、恒定强度的压力脉冲，几乎瞬时通过介质传播，在 0.8 μm 微量移液器尖端周围形成近乎球形的膨胀流体团。实验室模型实验表明，如果尖端雷诺数 Ret<0.03，则可以通过通过圆形孔口的准稳态斯托克斯流来密切模拟团块和压力场的增长。通过测量离散附着位点之间的树突状突起的偏转，并对树突状突起内的中央肌动蛋白丝束应用详细的超微结构模型，人们能够使用弹性梁理论计算探针产生的力。人们发现，当施加到细胞过程时，1 到 2.3 pN 之间的力足以启动电信号传导，但对于较软的细胞体则不然。更重要的是，只有当探针指向细胞过程中离散的焦点附着位点时，才会发生该过程的细胞激发。这表明电信号传导是在细胞过程中离散的焦点附着处启动的，并且这些位点可能是与拉伸激活的离子通道相关的整合素介导的复合物，尽管它们的分子结构未知。
A Stokesian fluid stimulus probe (SFSP), capable of delivering quantifiable pN level hydrodynamic forces, is developed to distinguish the electrophysiological response of the cell process and cell body of osteocyte-like MLO-Y4 cells without touching the cell or its substrate. The hydrodynamic disturbance is a short lived (100 ms), constant strength pressure pulse that propagates nearly instantaneously through the medium creating a nearly spherical expanding fluid bolus surrounding a 0.8 μm micropipette tip. Laboratory model experiments show that the growth of the bolus and the pressure field can be closely modeled by quasi-steady Stokes flow through a circular orifice provided the tip Reynolds number, Ret<0.03. By measuring the deflection of the dendritic processes between discrete attachment sites, and applying a detailed ultrastructural model for the central actin filament bundle within the process, one is able to calculate the forces produced by the probe using elastic beam theory. One finds that forces between 1 and 2.3 pN are sufficient to initiate electrical signaling when applied to the cell process, but not the much softer cell body. Even more significantly, cellular excitation by the process only occurs when the probe is directed at discrete focal attachment sites along the cell process. This suggests that electrical signaling is initiated at discrete focal attachments along the cell process and that these sites are likely integrin-mediated complexes associated with stretch-activated ion channels though their molecular structure is unknown.