Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK.
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA.
J R Soc Interface. 2023 Jul;20(204):20230184. doi: 10.1098/rsif.2023.0184. Epub 2023 Jul 19.
Although tissues are usually studied in isolation, this situation rarely occurs in biology, as cells, tissues and organs coexist and interact across scales to determine both shape and function. Here, we take a quantitative approach combining data from recent experiments, mathematical modelling and Bayesian parameter inference, to describe the self-assembly of multiple epithelial sheets by growth and collision. We use two simple and well-studied continuum models, where cells move either randomly or following population pressure gradients. After suitable calibration, both models prove to be practically identifiable, and can reproduce the main features of single tissue expansions. However, our findings reveal that whenever tissue-tissue interactions become relevant, the random motion assumption can lead to unrealistic behaviour. Under this setting, a model accounting for population pressure from different cell populations is more appropriate and shows a better agreement with experimental measurements. Finally, we discuss how tissue shape and pressure affect multi-tissue collisions. Our work thus provides a systematic approach to quantify and predict complex tissue configurations with applications in the design of tissue composites and more generally in tissue engineering.
尽管组织通常是孤立地进行研究的，但在生物学中这种情况很少见，因为细胞、组织和器官在不同尺度上共存并相互作用，以确定形状和功能。在这里，我们采用一种定量方法，结合最近的实验数据、数学建模和贝叶斯参数推断，来描述多个上皮片层通过生长和碰撞进行的自组装。我们使用了两个简单且经过充分研究的连续统模型，其中细胞要么随机移动，要么遵循群体压力梯度移动。经过适当的校准，这两个模型都被证明是实际可识别的，并且可以再现单个组织扩展的主要特征。然而，我们的研究结果表明，只要组织间的相互作用变得重要，随机运动的假设就可能导致不切实际的行为。在这种情况下，考虑来自不同细胞群体的群体压力的模型更为合适，并且与实验测量结果更吻合。最后，我们讨论了组织形状和压力如何影响多组织碰撞。我们的工作因此提供了一种定量和预测复杂组织构型的系统方法，可应用于组织复合材料的设计，更广泛地应用于组织工程。
