Nguyen Anh Q, Huang Junxiang, Bi Dapeng
Department of Physics and, Northeastern University, Boston, MA, USA.
Center for Theoretical Biological Physics, Northeastern University, Boston, MA, USA.
Nat Commun. 2025 Apr 5;16(1):3260. doi: 10.1038/s41467-025-58526-7.
During development and under normal physiological conditions, biological tissues are continuously subjected to substantial mechanical stresses. In response to large deformations, cells in a tissue must undergo multicellular rearrangements to maintain integrity and robustness. However, how these events are connected in time and space remains unknown. Here, using theoretical modeling, we study the mechanical plasticity of cell monolayers under large deformations. Our results suggest that the jamming-unjamming (solid-fluid) transition can vary significantly depending on the degree of deformation, implying that tissues are highly unconventional materials. We elucidate the origins of this behavior. We also demonstrate how large deformations are accommodated through a series of cellular rearrangements, similar to avalanches in non-living materials. We find that these 'tissue avalanches' are governed by stress redistribution and the spatial distribution of "soft" or vulnerable spots, which are more prone to undergo rearrangements. Finally, we propose a simple and experimentally accessible framework to infer tissue-level stress and predict avalanches based on static images.
在发育过程以及正常生理条件下，生物组织持续承受着巨大的机械应力。为响应大变形，组织中的细胞必须进行多细胞重排以维持完整性和稳健性。然而，这些事件在时间和空间上是如何关联的仍不为人知。在此，我们运用理论建模研究了大变形下细胞单层的机械可塑性。我们的结果表明，堵塞-解堵塞（固态-流体）转变会因变形程度而显著不同，这意味着组织是高度非常规的材料。我们阐明了这种行为的起源。我们还展示了大变形是如何通过一系列细胞重排来适应的，这类似于无生命材料中的崩塌。我们发现这些“组织崩塌”受应力重新分布以及“软”或易损点的空间分布所支配，这些点更易于发生重排。最后，我们提出了一个简单且实验上可实现的框架，用于基于静态图像推断组织水平的应力并预测崩塌。
