Cell prestress. I. Stiffness and prestress are closely associated in adherent contractile cells
Cell prestress. I. Stiffness and prestress are closely associated in adherent contractile cells
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DOI：
10.1152/ajpcell.00269.2001
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发表时间：
2002-03-01
影响因子：
5.5
通讯作者：
Stamenovic, D
中科院分区：
文献类型：
--
作者：
Wang, N;Tolic-Norrelykke, IM;Stamenovic, D
张拉整体假说认为细胞骨架是一种结构，其形状主要由丝状结构所承受的拉伸应力来稳定。因此，单元刚度必须与拉应力水平成比例地增加，这被称为预应力。在这里，我们在贴壁的人气道平滑肌（HASM）细胞中测试了这一预测。使用牵引显微镜测量每个细胞与其基质之间界面处产生的收缩应力分布；这种分布称为牵引场。由于牵引场必须由胞体内的拉应力平衡，因此可以计算出预应力。振荡磁扭细胞术测定细胞刚度(G)。当细胞的收缩状态被不同浓度的松弛或收缩激动剂（分别为异丙肾上腺素或组胺）调节时，平均预应力(t)范围为350至1,900 Pa。在此范围内，单元刚度随预应力G (Pa) = 0.18 (t) + 92线性增加。虽然这种联系并不一定排除其他解释，但它是主要通过预应力确保形状稳定的系统的标志。无论机制如何，这些数据建立了HASM细胞的刚度与细胞骨架内拉应力水平之间的强烈关联。
The tensegrity hypothesis holds that the cytoskeleton is a structure whose shape is stabilized predominantly by the tensile stresses borne by filamentous structures. Accordingly, cell stiffness must increase in proportion with the level of the tensile stress, which is called the prestress. Here we have tested that prediction in adherent human airway smooth muscle (HASM) cells. Traction microscopy was used to measure the distribution of contractile stresses arising at the interface between each cell and its substrate; this distribution is called the traction field. Because the traction field must be balanced by tensile stresses within the cell body, the prestress could be computed. Cell stiffness (G) was measured by oscillatory magnetic twisting cytometry. As the contractile state of the cell was modulated with graded concentrations of relaxing or contracting agonists (isoproterenol or histamine, respectively), the mean prestress ((t)) ranged from 350 to 1,900 Pa. Over that range, cell stiffness increased linearly with the prestress: G (Pa) = 0.18 (t) + 92. While this association does not necessarily preclude other interpretations, it is the hallmark of systems that secure shape stability mainly through the prestress. Regardless of mechanism, these data establish a strong association between stiffness of HASM cells and the level of tensile stress within the cytoskeleton.