Department of Mechanical Engineering, Iowa State University, Ames, IA 50011, USA.
Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
Int J Mol Sci. 2020 Jan 8;21(2):392. doi: 10.3390/ijms21020392.
Cytoskeleton morphology plays a key role in regulating cell mechanics. Particularly, cellular mechanical properties are directly regulated by the highly cross-linked and dynamic cytoskeletal structure of F-actin and microtubules presented in the cytoplasm. Although great efforts have been devoted to investigating the qualitative relation between the cellular cytoskeleton state and cell mechanical properties, comprehensive quantification results of how the states of F-actin and microtubules affect mechanical behavior are still lacking. In this study, the effect of both F-actin and microtubules morphology on cellular mechanical properties was quantified using atomic force microscope indentation experiments together with the proposed image recognition-based cytoskeleton quantification approach. Young's modulus and diffusion coefficient of NIH/3T3 cells with different cytoskeleton states were quantified at different length scales. It was found that the living NIH/3T3 cells sense and adapt to the F-actin and microtubules states: both the cellular elasticity and poroelasticity are closely correlated to the depolymerization degree of F-actin and microtubules at all measured indentation depths. Moreover, the significance of the quantitative effects of F-actin and microtubules in affecting cellular mechanical behavior is depth-dependent.
细胞骨架形态在调节细胞力学中起着关键作用。特别是，细胞质中高度交联和动态的 F-肌动蛋白和微管细胞骨架结构直接调节细胞的力学特性。尽管已经投入大量精力研究细胞细胞骨架状态和细胞力学特性之间的定性关系，但仍缺乏关于 F-肌动蛋白和微管状态如何影响力学行为的综合定量结果。在这项研究中，使用原子力显微镜压痕实验和提出的基于图像识别的细胞骨架定量方法，定量研究了 F-肌动蛋白和微管形态对细胞力学特性的影响。在不同的细胞骨架状态下，定量了 NIH/3T3 细胞的杨氏模量和扩散系数在不同的长度尺度上。结果表明，活的 NIH/3T3 细胞能够感知并适应 F-肌动蛋白和微管的状态：在所有测量的压痕深度上，细胞弹性和多孔弹性都与 F-肌动蛋白和微管的解聚程度密切相关。此外，F-肌动蛋白和微管对细胞力学行为的定量影响的意义是深度依赖的。
