Relationship between cell stiffness and stress fiber amount, assessed by simultaneous atomic force microscopy and live-cell fluorescence imaging.
Relationship between cell stiffness and stress fiber amount, assessed by simultaneous atomic force microscopy and live-cell fluorescence imaging.
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DOI：
10.1007/s10237-015-0706-9
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发表时间：
2016-06
影响因子：
3.5
通讯作者：
Chadwick RS
中科院分区：
文献类型：
--
作者：
Gavara N;Chadwick RS
肌动球蛋白应力纤维是细胞骨架的主要成分之一，通过在细胞-ECM粘附位点处向细胞外基质（ECM）施加和传递张力来为粘附细胞提供机械稳定性。虽然人们普遍认为应力纤维的空间和时间分布的变化会影响细胞的机械性能，但关于应力纤维的数量和组织如何直接调节细胞刚度还没有定量的知识。我们解决这个关键的开放问题，结合原子力显微镜与活细胞的同步荧光成像，并联合收割机首次从这两种技术获得可靠的定量参数。我们发现，肌球蛋白和（在较小程度上）肌动蛋白组装在应力纤维直接调节粘附小鼠成纤维细胞（NIH 3 T3）的细胞刚度。此外，应力纤维的空间分布具有二阶调制效应。特别地，位于单元周边的纤维、对齐的纤维或较厚的纤维的存在引起增强的单元刚度。我们的研究结果提供了基本的和重要的信息，这将有助于设计最佳的协议，以调节粘附细胞的机械性能，通过药理学干预，改变应力纤维组装或通过微图案化技术，限制应力纤维的空间组织。本文的在线版本（doi：10.1007/s10237-015-0706-9）包含补充材料，可供授权用户使用。
Actomyosin stress fibers, one of the main components of the cell’s cytoskeleton, provide mechanical stability to adherent cells by applying and transmitting tensile forces onto the extracellular matrix (ECM) at the sites of cell–ECM adhesion. While it is widely accepted that changes in spatial and temporal distribution of stress fibers affect the cell’s mechanical properties, there is no quantitative knowledge on how stress fiber amount and organization directly modulate cell stiffness. We address this key open question by combining atomic force microscopy with simultaneous fluorescence imaging of living cells, and combine for the first time reliable quantitative parameters obtained from both techniques. We show that the amount of myosin and (to a lesser extent) actin assembled in stress fibers directly modulates cell stiffness in adherent mouse fibroblasts (NIH3T3). In addition, the spatial distribution of stress fibers has a second-order modulatory effect. In particular, the presence of either fibers located in the cell periphery, aligned fibers or thicker fibers gives rise to reinforced cell stiffness. Our results provide basic and significant information that will help design optimal protocols to regulate the mechanical properties of adherent cells via pharmacological interventions that alter stress fiber assembly or via micropatterning techniques that restrict stress fiber spatial organization. The online version of this article (doi:10.1007/s10237-015-0706-9) contains supplementary material, which is available to authorized users.