Bansod Yogesh Deepak, Matsumoto Takeo, Nagayama Kazuaki, Bursa Jiri
Faculty of Mechanical Engineering (FME), Institute of Solid Mechanics, Mechatronics and Biomechanics (ISMMB), Brno University of Technology (BUT), Technicka 2896/2, Brno 61669, Czech Republic e-mail: .
Biomechanics Laboratory, Department of Mechanical Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan e-mail: .
J Biomech Eng. 2018 Oct 1;140(10). doi: 10.1115/1.4040246.
Mechanical interaction of cell with extracellular environment affects its function. The mechanisms by which mechanical stimuli are sensed and transduced into biochemical responses are still not well understood. Considering this, two finite element (FE) bendo-tensegrity models of a cell in different states are proposed with the aim to characterize cell deformation under different mechanical loading conditions: a suspended cell model elucidating the global response of cell in tensile test simulation and an adherent cell model explicating its local response in atomic force microscopy (AFM) indentation simulation. The force-elongation curve obtained from tensile test simulation lies within the range of experimentally obtained characteristics of smooth muscle cells (SMCs) and illustrates a nonlinear increase in reaction force with cell stretching. The force-indentation curves obtained from indentation simulations lie within the range of experimentally obtained curves of embryonic stem cells (ESCs) and exhibit the influence of indentation site on the overall reaction force of cell. Simulation results have demonstrated that actin filaments (AFs) and microtubules (MTs) play a crucial role in the cell stiffness during stretching, whereas actin cortex (AC) along with actin bundles (ABs) and MTs are essential for the cell rigidity during indentation. The proposed models quantify the mechanical contribution of individual cytoskeletal components to cell mechanics and the deformation of nucleus under different mechanical loading conditions. These results can aid in better understanding of structure-function relationships in living cells.
细胞与细胞外环境的机械相互作用会影响其功能。机械刺激被感知并转化为生化反应的机制仍未得到充分理解。考虑到这一点，提出了处于不同状态的细胞的两个有限元（FE）弯曲张拉整体模型，旨在表征不同机械加载条件下的细胞变形：一个悬浮细胞模型，用于阐明拉伸试验模拟中细胞的整体反应；一个贴壁细胞模型，用于解释原子力显微镜（AFM）压痕模拟中细胞的局部反应。从拉伸试验模拟获得的力-伸长曲线处于实验获得的平滑肌细胞（SMC）特性范围内，并表明随着细胞拉伸，反作用力呈非线性增加。从压痕模拟获得的力-压痕曲线处于实验获得的胚胎干细胞（ESC）曲线范围内，并显示了压痕位置对细胞整体反作用力的影响。模拟结果表明，肌动蛋白丝（AFs）和微管（MTs）在拉伸过程中对细胞刚度起关键作用，而肌动蛋白皮质（AC）连同肌动蛋白束（ABs）和MTs在压痕过程中对细胞刚性至关重要。所提出的模型量化了单个细胞骨架成分在不同机械加载条件下对细胞力学和细胞核变形的机械贡献。这些结果有助于更好地理解活细胞中的结构-功能关系。
