发表机构
Max Planck Institute for the Physics of Complex Systems; Max Planck Institute of Molecular Cell Biology and Genetics; Center for Systems Biology Dresden（马克斯·普朗克复杂系统物理研究所; 马克斯·普朗克分子细胞生物学与遗传学研究所; 德累斯顿系统生物学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过最小顶点模型揭示细胞质力学贡献可使上皮单层压缩屈曲转变在中间模量范围内变为非连续，并用六阶朗道理论三临界点解释该重入行为，表明细胞尺度力学可定性改变组织尺度行为。
AI 中文摘要
细胞皮层和细胞粘附共同决定了上皮细胞及其组织的力学性质。上皮组织的顶点模型通常表征细胞皮层和细胞粘附，但这些模型大多忽略了构成皮层所包围的细胞质的其他亚细胞结构。在此，我们在一个最小化的上皮单层顶点模型中揭示了这些结构的力学后果，其中单细胞能量包含一项细胞质贡献，该贡献代表了例如胞质聚合物受限的代价。引人注目的是，我们的模拟表明，在相关细胞质模量的中间值范围内，单层在压缩下的屈曲转变变得不连续。通过在模型的连续极限下对该屈曲问题进行渐近求解，我们利用六阶朗道理论的三临界点解释了这种重入行为。因此，我们的结果强调了皮层和细胞粘附之外的细胞尺度力学如何能够定性甚至改变涌现的组织尺度行为。
英文摘要
The cell cortex and cell adhesion contribute to the mechanics of epithelial cells and hence tissues. Vertex models of epithelia represent the cell cortex and cell adhesion, but these models mostly ignore the other subcellular structures that compose the cytoplasm surrounded by the cortex. Here, we reveal the mechanical consequences of these structures in a minimal vertex model of an epithelial monolayer, in which the single-cell energy includes a cytoplasmic contribution that represents, e.g., the cost of confinement of cytosolic polymers. Strikingly, our simulations show that the buckling transition of the monolayer under compression becomes discontinuous in an intermediate range of values of the associated cytoplasmic modulus. By asymptotic solution of this buckling problem in the continuum limit of the model, we explain this reentrant behaviour in terms of the tricritical points of a sixth-order Landau theory. Our results thus underline how cell-scale mechanics beyond the cortex and cell adhesion can change emergent, tissue-scale behaviour even qualitatively.
Comments12 pages, 6 figures
