Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension.
Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension.
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DOI：
10.1016/s0006-3495(94)81014-8
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发表时间：
1994-06
影响因子：
3.4
通讯作者：
Ning Wang;D. Ingber
中科院分区：
文献类型：
--
作者：
Ning Wang;D. Ingber
我们研究了细胞外基质（ECM）如何改变细胞骨架（CSK）的力学特性。利用rgd包被的铁磁微珠（直径5.5微米）和磁扭转装置对贴壁内皮细胞顶端表面的整合素受体施加机械应力。通过将纤维连接蛋白（FN）涂层密度从10 ng/cm2提高到500 ng/cm2，增加基底细胞- ecm接触的数量，促进细胞扩散五倍，并增加CSK刚度、表观粘度和永久变形，这些都是对最大应力（40 dyne/cm2）的响应。当外加应力从7达因/平方厘米增加到40达因/平方厘米时，CSK的刚度和表观粘度平行增加，但胞体形状、ECM接触和永久变形没有改变。使用较小的微球（直径1.4微米）在较低数量的ECM接触上施加相同的应力，导致CSK刚度和表观粘度下降，这证实了该技术探测到CSK的深度，而不仅仅是皮质膜。当使用细胞膜被破坏和ATP储存被皂苷耗尽的细胞进行磁测量时，发现CSK刚度和表观粘度增加了约20%，而永久变形减少了一半以上。在促进膜渗透细胞中CSK张力产生的条件下，添加ATP（250微米）导致CSK刚度和表观粘度下降，在ATP添加后2min内可以检测到，而细胞大小没有任何可测量的变化。（摘要删节250字）
We have investigated how extracellular matrix (ECM) alters the mechanical properties of the cytoskeleton (CSK). Mechanical stresses were applied to integrin receptors on the apical surfaces of adherent endothelial cells using RGD-coated ferromagnetic microbeads (5.5-microns diameter) in conjunction with a magnetic twisting device. Increasing the number of basal cell-ECM contacts by raising the fibronectin (FN) coating density from 10 to 500 ng/cm2 promoted cell spreading by fivefold and increased CSK stiffness, apparent viscosity, and permanent deformation all by more than twofold, as measured in response to maximal stress (40 dyne/cm2). When the applied stress was increased from 7 to 40 dyne/cm2, the stiffness and apparent viscosity of the CSK increased in parallel, although cell shape, ECM contacts, nor permanent deformation was altered. Application of the same stresses over a lower number ECM contacts using smaller beads (1.4-microns diameter) resulted in decreased CSK stiffness and apparent viscosity, confirming that this technique probes into the depth of the CSK and not just the cortical membrane. When magnetic measurements were carried out using cells whose membranes were disrupted and ATP stores depleted using saponin, CSK stiffness and apparent viscosity were found to rise by approximately 20%, whereas permanent deformation decreased by more than half. Addition of ATP (250 microM) under conditions that promote CSK tension generation in membrane-permeabilized cells resulted in decreases in CSK stiffness and apparent viscosity that could be detected within 2min after ATP addition, before any measurable change in cell size.(ABSTRACT TRUNCATED AT 250 WORDS)