Phys Rev Lett:中国科大姜洪源研究组发表细胞力学研究进展

2016年5月19日，《Physical Review Letters》杂志在线发表了中国科学技术大学工程科学学院近代力学系、中科院材料力学行为和设计重点实验室教授姜洪源团队深入研究了细胞的动态粘附和脱粘过程，研究成果题为Shape and Dynamics of Adhesive Cells: Mechanical Response of Open Systems 。博士生杨月华为第一作者，姜洪源为通讯作者。

细胞粘附是生物学中的基本现象。理解细胞粘附和脱粘的力学生物学机制，对理解细胞迁移、硬度感知、胚胎发育、细胞分化等生命现象并进一步指导改进细胞力学性质的测量方法与精度，具有重要意义。然而，目前的理论和实验研究总是忽略在动态粘附过程中的细胞与周围环境的物质交换，从而忽略细胞体积和压力的变化，把细胞简化为弹性球体或粘性液滴。

在该工作中，姜洪源团队在前期对细胞体积和压力调控机制的研究(Biophysical Journal, 105:609-619 (2013))和细胞在受限空间内的迁移机制的研究(Cell. 157: 611–623 (2014))的基础之上，进一步将细胞作为开放系统，研究了细胞体积和压力调控如何影响粘附在两个平行表面间的细胞的形貌和动力学。研究人员发现，取决于粘附能密度、两个表面的间距、细胞的大小和柔性表面的刚度，粘附细胞可以是稳定的(凸的或凹的)或不稳定的(自发破裂或崩溃)。在此基础之上，研究人员发现凸、凹细胞的动态脱粘过程是完全不同的，加载速率与细胞体积调控之间的竞争显著影响粘附细胞的力学响应。最后，研究人员发现，作为开放系统，贴壁细胞的脱粘也受到加载历史的极大影响。该结果揭示了细胞体积是细胞力学的一个关键参数，对理解细胞粘附相关过程和改进实验方法具有重要意义。

原文链接：

Shape and Dynamics of Adhesive Cells: Mechanical Response of Open Systems

原文摘要：

Cell adhesion is an essential biological process. However, previous theoretical and experimental studies ignore a key variable, the changes of cellular volume and pressure, during the dynamic adhesion process. Here, we treat cells as open systems and propose a theoretical framework to investigate how the exchange of water and ions with the environment affects the shape and dynamics of cells adhered between two adhesive surfaces. We show that adherent cells can be either stable (convex or concave) or unstable (spontaneous rupture or collapse) depending on the adhesion energy density, the cell size, the separation of two adhesive surfaces, and the stiffness of the flexible surface. Strikingly, we find that the unstable states vanish when cellular volume and pressure are constant. We further show that the detachments of convex and concave cells are very different. The mechanical response of adherent cells is mainly determined by the competition between the loading rate and the regulation of the cellular volume and pressure. Finally, we show that as an open system the detachment of adherent cells is also significantly influenced by the loading history. Thus, our findings reveal a major difference between living cells and nonliving materials.

doi:10.1103/PhysRevLett.118.208102

作者：姜洪源