School of Mathematics, University of Bristol, Bristol, BS8 1TW, United Kingdom.
Institute of Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom.
Nat Commun. 2020 Mar 16;11(1):1405. doi: 10.1038/s41467-020-15164-5.
Epithelial cell monolayers show remarkable displacement and velocity correlations over distances of ten or more cell sizes that are reminiscent of supercooled liquids and active nematics. We show that many observed features can be described within the framework of dense active matter, and argue that persistent uncoordinated cell motility coupled to the collective elastic modes of the cell sheet is sufficient to produce swirl-like correlations. We obtain this result using both continuum active linear elasticity and a normal modes formalism, and validate analytical predictions with numerical simulations of two agent-based cell models, soft elastic particles and the self-propelled Voronoi model together with in-vitro experiments of confluent corneal epithelial cell sheets. Simulations and normal mode analysis perfectly match when tissue-level reorganisation occurs on times longer than the persistence time of cell motility. Our analytical model quantitatively matches measured velocity correlation functions over more than a decade with a single fitting parameter.
上皮细胞单层在超过十个细胞大小的距离上表现出显著的位移和速度相关性，这让人联想到过冷液体和活性向列相。我们表明，许多观察到的特征可以在密集活性物质的框架内进行描述，并认为持续的不协调细胞运动与细胞片的集体弹性模式相结合足以产生漩涡状相关性。我们使用连续活性线弹性和正常模式形式化方法获得了这个结果，并通过两个基于代理的细胞模型、软弹性颗粒和自主推进的 Voronoi 模型的数值模拟以及角膜上皮细胞片的体外实验验证了分析预测。当组织水平的重新组织发生在比细胞运动的持久性更长的时间时，模拟和正常模式分析完美匹配。我们的分析模型定量匹配了超过十年的测量速度相关函数，只需一个拟合参数。
