Physics Department, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Physics Department and BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA.
Soft Matter. 2019 Nov 28;15(44):9133-9149. doi: 10.1039/c9sm00916g. Epub 2019 Nov 1.
Recent work on particle-based models of tissues has suggested that any finite rate of cell division and cell death is sufficient to fluidize an epithelial tissue. At the same time, experimental evidence has indicated the existence of glassy dynamics in some epithelial layers despite continued cell cycling. To address this discrepancy, we quantify the role of cell birth and death on glassy states in confluent tissues using simulations of an active vertex model that includes cell motility, cell division, and cell death. Our simulation data is consistent with a simple ansatz in which the rate of cell-life cycling and the rate of relaxation of the tissue in the absence of cell cycling contribute independently and additively to the overall rate of cell motion. Specifically, we find that a glass-like regime with caging behavior indicated by subdiffusive cell displacements can be achieved in systems with sufficiently low rates of cell cycling.
最近基于粒子的组织模型研究表明，任何有限的细胞分裂和细胞死亡速率都足以使上皮组织流体化。与此同时，实验证据表明，尽管细胞持续循环，但在一些上皮层中存在玻璃态动力学。为了解决这一差异，我们使用包括细胞迁移、细胞分裂和细胞死亡的活性顶点模型来模拟，定量研究细胞出生和死亡对细胞融合组织中玻璃态的作用。我们的模拟数据与一个简单的假定一致，即细胞生命循环的速率和组织在没有细胞循环的情况下的松弛速率独立且累加地贡献于细胞运动的整体速率。具体来说，我们发现，在细胞循环率足够低的系统中，可以实现具有笼状行为的类玻璃态，这表现为亚扩散的细胞位移。
