Gross Ben Jeffrey, Soltwedel Johannes Richard, Shelton Elijah, Gomez Carlos, Campàs Otger
Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany.
Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA.
Sci Rep. 2025 Aug 5;15(1):28599. doi: 10.1038/s41598-025-13419-z.
From cellular mechanotransduction to the formation of embryonic tissues and organs, mechanics has been shown to play an important role in the control of cell behavior and embryonic development. Most of our existing knowledge of how mechanics affects cell behavior comes from in vitro studies, mainly because measuring cell and tissue mechanics in 3D multicellular systems, and especially in vivo, remains challenging. Oil microdroplet sensors, and more recently gel microbeads, use surface deformations to directly quantify mechanical stresses within developing tissues, in vivo and in situ, as well as in 3D in vitro systems like organoids or multicellular spheroids. However, an automated analysis software able to quantify the spatiotemporal evolution of stresses and their characteristics from particle deformations is lacking. Here we develop STRESS (Surface Topography Reconstruction for Evaluation of Spatiotemporal Stresses), an analysis software to quantify the geometry of deformable particles of spherical topology, such as microdroplets or gel microbeads, that enables the automatic quantification of the temporal evolution of stresses in the system and the spatiotemporal features of stress inhomogeneities in the tissue. As a test case, we apply these new code to measure the temporal evolution of mechanical stresses using oil microdroplets in developing zebrafish tissues. Starting from a 3D timelapse of a droplet, the software automatically calculates the statistics of local anisotropic stresses, decouples the deformation modes associated with tissue- and cell-scale stresses, obtains their spatial features on the droplet surface and analyzes their spatiotemporal variations using spatial and temporal stress autocorrelations. We provide fully automated software in Matlab/Python and also in Napari (napari-STRESS), which allows the visualization of mechanical stresses on the droplet surface together with the microscopy images of the biological systems. The automated nature of the analysis will help users obtain quantitative information about mechanical stresses in a wide range of 3D multicellular systems, from developing embryos or tissue explants to organoids.
从细胞机械转导到胚胎组织和器官的形成，力学已被证明在控制细胞行为和胚胎发育中发挥着重要作用。我们目前关于力学如何影响细胞行为的大部分知识来自体外研究，主要是因为在三维多细胞系统中，尤其是在体内测量细胞和组织力学仍然具有挑战性。油微滴传感器，以及最近的凝胶微珠，利用表面变形直接量化发育中的组织内、体内和原位以及类器官或多细胞球体等三维体外系统中的机械应力。然而，缺乏一种能够根据颗粒变形量化应力的时空演变及其特征的自动化分析软件。在这里，我们开发了STRESS（用于评估时空应力的表面形貌重建），这是一种分析软件，用于量化球形拓扑结构的可变形颗粒（如微滴或凝胶微珠）的几何形状，能够自动量化系统中应力的时间演变以及组织中应力不均匀性的时空特征。作为一个测试案例，我们应用这些新代码，使用油微滴测量斑马鱼发育组织中机械应力的时间演变。从液滴的三维延时图像开始，该软件自动计算局部各向异性应力的统计数据，解耦与组织和细胞尺度应力相关的变形模式，在液滴表面获取它们的空间特征，并使用空间和时间应力自相关分析它们的时空变化。我们在Matlab/Python以及Napari（napari - STRESS）中提供了完全自动化的软件，该软件允许在液滴表面可视化机械应力以及生物系统的显微镜图像。分析的自动化性质将帮助用户在从发育中的胚胎或组织外植体到类器官的广泛三维多细胞系统中获得关于机械应力的定量信息。
