M.V. Lomonosov Moscow State University, Faculty of Biology, Department of Bioengineering, Leninskie Gory, 1/73, 111991 Moscow, Russia.
J Biomech. 2013 Apr 5;46(6):1081-7. doi: 10.1016/j.jbiomech.2013.01.022. Epub 2013 Feb 28.
Mechanical properties of cells depend on various external and internal factors, like substrate stiffness and surface modifications, cell ageing and disease state. Some other currently unknown factors may exist. In this study we used force spectroscopy by AFM, confocal microscopy and flow cytometry to investigate the difference between single non-confluent and confluent (in monolayer) Vero cells. In all cases the stiffness values were fitted by log-normal rather than normal distribution. Log-normal distribution was also found for an amount of cortical actin in cells by flow cytometry. Cells in the monolayer were characterized by a significantly lower (1.4-1.7 times) Young's modulus and amount of cortical actin than in either of the single non-confluent cells or cells migrating in the experimental wound. Young's modulus as a function of indentation speed followed a weak power law for all the studied cell states, while the value of the exponent was higher for cells growing in monolayer. These results show that intercellular contacts and cell motile state significantly influence the cell mechanical properties.
细胞的力学特性取决于各种外部和内部因素，如基质硬度和表面修饰、细胞老化和疾病状态。可能还存在一些其他目前未知的因素。在这项研究中，我们使用原子力显微镜的力谱学、共聚焦显微镜和流式细胞术来研究非融合的单个细胞和单层融合（单层）Vero 细胞之间的差异。在所有情况下，拟合的硬度值均符合对数正态分布，而不是正态分布。通过流式细胞术也发现了细胞中皮质肌动蛋白的量呈对数正态分布。与单个非融合细胞或在实验性伤口中迁移的细胞相比，单层中的细胞的杨氏模量和皮质肌动蛋白的量明显更低（低 1.4-1.7 倍）。杨氏模量作为压痕速度的函数，对于所有研究的细胞状态，均遵循弱幂律，而对于在单层中生长的细胞，该指数的值更高。这些结果表明细胞间接触和细胞迁移状态显著影响细胞的力学特性。
