He Xiuxiu, Jiang Yi
Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, United States of America.
Phys Biol. 2017 May 23;14(3):035006. doi: 10.1088/1478-3975/aa6f8e.
Cell migration is essential in many aspects of biology. Many basic migration processes, including adhesion, membrane protrusion and tension, cytoskeletal polymerization, and contraction, have to act in concert to regulate cell migration. At the same time, substrate topography modulates these processes. In this work, we study how substrate curvature at micrometer scale regulates cell motility. We have developed a 3D mechanical model of single cell migration and simulated migration on curved substrates with different curvatures. The simulation results show that cell migration is more persistent on concave surfaces than on convex surfaces. We have further calculated analytically the cell shape and protrusion force for cells on curved substrates. We have shown that while cells spread out more on convex surfaces than on concave ones, the protrusion force magnitude in the direction of migration is larger on concave surfaces than on convex ones. These results offer a novel biomechanical explanation to substrate curvature regulation of cell migration: geometric constrains bias the direction of the protrusion force and facilitates persistent migration on concave surfaces.
细胞迁移在生物学的许多方面都至关重要。许多基本的迁移过程，包括黏附、膜突出和张力、细胞骨架聚合以及收缩，必须协同作用来调节细胞迁移。同时，基底形貌会调节这些过程。在这项工作中，我们研究微米尺度的基底曲率如何调节细胞运动。我们开发了一个单细胞迁移的三维力学模型，并模拟了在具有不同曲率的弯曲基底上的迁移。模拟结果表明，细胞在凹面上的迁移比在凸面上更持久。我们进一步通过解析计算了弯曲基底上细胞的形状和突出力。我们已经表明，虽然细胞在凸面上比在凹面上铺展得更多，但在迁移方向上的突出力大小在凹面上比在凸面上更大。这些结果为基底曲率对细胞迁移的调节提供了一种新的生物力学解释：几何约束使突出力的方向产生偏差，并促进细胞在凹面上的持续迁移。
