论文标题
底物刚度在组织扩散中的作用：润湿过渡和组织
Role of Substrate Stiffness in Tissue Spreading: Wetting Transition and Tissue Durotaxis
论文作者
论文摘要
活组织进行润湿过渡：在表面上，它们可以形成液滴样细胞骨料，或作为迁移细胞的单层传播。组织润湿不仅取决于化学物质，还取决于底物的机械性能。在这里，我们研究了底物刚度在组织扩散中的作用，我们通过活性极性流体模型来描述。考虑到细胞在更硬的底物上施加较大的活性牵引力，我们预测在临界底物刚度下组织润湿过渡，随组织尺寸降低。在具有刚度梯度的底物上，我们发现组织在更硬的一侧扩散。此外，我们表明组织可以在较软的一侧脱水时润湿固定侧的底物。我们还表明，通过在整个组织中传播的粘性力，更硬的端子可以瞬时将较软的侧面界面拖动到刚度增加刚度，以抗其扩散趋势。这两种影响导致组织的僵硬梯度向上迁移。因此，这种现象 - 组织 - 杜罗塔克斯 - 因此可以从柔软的一面脱水和组织界面之间的流体动力相互作用中出现。总体而言，我们的工作揭示了底物刚度影响的集体迁移和活组织的主动润湿特性，这些机制与发育，再生和癌症相关。
Living tissues undergo wetting transitions: On a surface, they can either form a droplet-like cell aggregate or spread as a monolayer of migrating cells. Tissue wetting depends not only on the chemical but also on the mechanical properties of the substrate. Here, we study the role of substrate stiffness in tissue spreading, which we describe by means of an active polar fluid model. Taking into account that cells exert larger active traction forces on stiffer substrates, we predict a tissue wetting transition at a critical substrate stiffness that decreases with tissue size. On substrates with a stiffness gradient, we find that the tissue spreads faster on the stiffer side. Further, we show that the tissue can wet the substrate on the stiffer side while dewetting from the softer side. We also show that, by means of viscous forces transmitted across the tissue, the stiffer-side interface can transiently drag the softer-side interface towards increasing stiffness, against its spreading tendency. These two effects result in directed tissue migration up the stiffness gradient. This phenomenon -- tissue durotaxis -- can thus emerge both from dewetting at the soft side and from hydrodynamic interactions between the tissue interfaces. Overall, our work unveils mechanisms whereby substrate stiffness impacts the collective migration and the active wetting properties of living tissues, which are relevant in development, regeneration, and cancer.
