Temporal Variation in Single-Cell Power-Law Rheology Spans the Ensemble Variation of Cell Population
Temporal Variation in Single-Cell Power-Law Rheology Spans the Ensemble Variation of Cell Population
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DOI：
10.1016/j.bpj.2017.06.025
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发表时间：
2017-08-08
影响因子：
3.4
通讯作者：
Okajima, Takaharu
中科院分区：
文献类型：
--
作者：
Cai, PingGen;Takahashi, Ryosuke;Okajima, Takaharu
细胞内细胞骨架组织的变化可以通过细胞流变特性的大的空间和时间变化来表征（例如，复数剪切模量G（星星））。虽然单细胞G（星星）的系综变化已经被阐明，但G（星星）的详细时间变化仍然未知。在这项研究中，我们研究了在空间受限的环境下，单个成纤维细胞的流变学特性如何变化，在该环境中，细胞的平移运动受到高度限制，整个细胞的形状保持不变。单细胞流变学的时间演变在细胞内相同的测量位置进行探测，使用原子力显微镜基于振荡变形。测量结果表明，在幂律流变的细胞的时间变化是定量一致的合奏变化，表明细胞系统满足遍历假设，其中的时间统计是相同的合奏统计。G（星星）的自相关性意味着细胞力学状态在具有特征时间尺度的可能状态的系综中演化。
Changes in the cytoskeletal organization within cells can be characterized by large spatial and temporal variations in rheological properties of the cell (e.g., the complex shear modulus G(star)). Although the ensemble variation in G(star) of single cells has been elucidated, the detailed temporal variation of G(star) remains unknown. In this study, we investigated how the rheological properties of individual fibroblast cells change under a spatially confined environment in which the cell translational motion is highly restricted and the whole cell shape remains unchanged. The temporal evolution of single-cell rheology was probed at the same measurement location within the cell, using atomic force microscopy-based oscillatory deformation. The measurements reveal that the temporal variation in the power-law rheology of cells is quantitatively consistent with the ensemble variation, indicating that the cell system satisfies an ergodic hypothesis in which the temporal statistics are identical to the ensemble statistics. The autocorrelation of G(star) implies that the cell mechanical state evolves in the ensemble of possible states with a characteristic timescale.