Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), 08028, Barcelona, Spain.
Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
Nat Commun. 2023 Jul 7;14(1):4014. doi: 10.1038/s41467-023-38879-7.
The function of organs such as lungs, kidneys and mammary glands relies on the three-dimensional geometry of their epithelium. To adopt shapes such as spheres, tubes and ellipsoids, epithelia generate mechanical stresses that are generally unknown. Here we engineer curved epithelial monolayers of controlled size and shape and map their state of stress. We design pressurized epithelia with circular, rectangular and ellipsoidal footprints. We develop a computational method, called curved monolayer stress microscopy, to map the stress tensor in these epithelia. This method establishes a correspondence between epithelial shape and mechanical stress without assumptions of material properties. In epithelia with spherical geometry we show that stress weakly increases with areal strain in a size-independent manner. In epithelia with rectangular and ellipsoidal cross-section we find pronounced stress anisotropies that impact cell alignment. Our approach enables a systematic study of how geometry and stress influence epithelial fate and function in three-dimensions.
器官（如肺、肾和乳腺）的功能依赖于其上皮的三维几何形状。为了采用球体、管体和椭球体等形状，上皮会产生通常未知的机械应力。在这里，我们设计了具有可控尺寸和形状的弯曲上皮单层，并绘制了它们的应力状态图。我们设计了具有圆形、矩形和椭圆形足迹的加压上皮。我们开发了一种称为弯曲单层应微镜的计算方法，以绘制这些上皮中的应力张量。该方法在不假设材料特性的情况下，在单层形状和机械应力之间建立了对应关系。在具有球形几何形状的上皮中，我们表明应力以与面积应变无关的方式随面积应变弱增。在具有矩形和椭圆形横截面的上皮中，我们发现了明显的各向异性应力，这会影响细胞排列。我们的方法能够系统地研究三维几何形状和应力如何影响上皮的命运和功能。
