Department of Mechanical, Industrial and Systems Engineering, University of Rhode Island, Kingston, RI, 02881, USA.
Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, 100871, China.
Biomech Model Mechanobiol. 2018 Jun;17(3):915-922. doi: 10.1007/s10237-018-1001-3. Epub 2018 Jan 22.
Durotaxis refers to the phenomenon in which cells can sense the spatial gradient of the substrate rigidity in the process of cell migration. A conceptual two-part theory consisting of the focal adhesion force generation and mechanotransduction has been proposed previously by Lo et al. to explain the mechanism underlying durotaxis. In the present work, we are concerned with the first part of the theory: how exactly is the larger focal adhesion force generated in the part of the cell adhering to the stiffer region of the substrate? Using a simple elasticity model and by assuming the cell adheres to the substrate continuously underneath the whole cell body, we show that the mechanics principle of static equilibrium alone is sufficient to account for the generation of the larger traction stress on the stiffer region of the substrate. We believe that our model presents a simple mechanistic understanding of mechanosensing of substrate stiffness gradient at the cellular scale, which can be incorporated in more sophisticated mechanobiochemical models to address complex problems in mechanobiology and bioengineering.
趋硬性是指细胞在迁移过程中能够感知基质硬度的空间梯度的现象。Lo 等人之前提出了一个由两部分组成的概念性理论，用于解释趋硬性的机制，该理论包括粘着斑力的产生和力转导。在本工作中，我们关注的是该理论的第一部分：细胞中哪一部分能够产生更大的粘着斑力，从而附着在基质较硬的区域？通过使用简单的弹性模型，并假设细胞在整个细胞体下面连续地附着在基质上，我们表明仅通过静力学平衡的力学原理就足以解释在基质较硬的区域产生更大的牵引力。我们相信，我们的模型为细胞尺度上的基质硬度梯度的力学感受提供了一个简单的力学理解，可以将其纳入更复杂的机械生化模型中，以解决机械生物学和生物工程中的复杂问题。
