Contribution of actin filaments to the global compressive properties of fibroblasts
Contribution of actin filaments to the global compressive properties of fibroblasts
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DOI：
10.1016/j.jmbbm.2012.05.006
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发表时间：
2012-10-01
影响因子：
3.9
通讯作者：
Wada, Shigeo
中科院分区：
文献类型：
--
作者：
Ujihara, Yoshihiro;Nakamura, Masanori;Wada, Shigeo
肌动蛋白丝通常被认为是张力承载元件。在这里，我们研究了肌动蛋白丝对细胞整体压缩性能的影响实验和数值。从成熟日本白色兔的髌腱收获成纤维细胞，并用细胞松弛素D处理以使肌动蛋白丝脱纤维。对完整细胞和具有断裂的肌动蛋白丝的细胞进行压缩测试。每个浮动单元被保持在悬臂和压缩板之间，并且通过用线性致动器移动压缩板来压缩，以获得准静态条件下的载荷-变形曲线。实验结果表明，断裂的肌动蛋白丝的细胞的初始刚度下降了51%。实验结束后，我们模拟了细胞的压缩测试有/没有成束的肌动蛋白丝。一束肌动蛋白丝被建模为一个张力轴承组件，只有当它被拉长时才会产生基于胡克定律的力。相比之下，如果它被缩短，它被认为不施加任何力。计算结果表明，肌动蛋白纤维束的排列方式对细胞刚度有显著影响。此外，被动重定向束的肌动蛋白丝垂直于压缩诱导的阻力增加的垂直伸长的细胞，从而增加了细胞的刚度。这些结果清楚地表明，肌动蛋白纤维束有助于细胞的压缩特性，即使它们是张力轴承组件。(C)2012爱思唯尔有限公司保留所有权利。
Actin filaments are often regarded as tension-bearing components. Here, we examined the effects of actin filaments on global compressive properties of cells experimentally and numerically. Fibroblasts were harvested from the patellar tendon of a mature Japanese white rabbit and treated with cytochalasin D to depolymerize the actin filaments. Intact cells and cells with disrupted actin filaments were subjected to the compressive tests. Each floating cell was held between the cantilever and compressive plates and compressed by moving the compressive plate with a linear actuator to obtain a load-deformation curve under quasi-static conditions. The experimental results demonstrated that the initial stiffness of a cell with disrupted actin filaments decreased by 51%. After the experiments, we simulated the compressive test of cells with/without bundles of actin filaments. A bundle of actin filaments was modeled as a tension-bearing component that generates a force based on Hooke's law only when it was elongated. By contrast, if it was shortened, it was assumed to exert no force. The computational results revealed that the alignment of bundles of actin filaments significantly affected the cell stiffness. In addition, the passive reorientation of bundles of actin filaments perpendicular to the compression induced an increase in the resistance to the vertical elongation of a cell and thereby increased the cell stiffness. These results clearly indicated that bundles of actin filaments contribute to the compressive properties of a cell, even if they are tension-bearing components. (C) 2012 Elsevier Ltd. All rights reserved.