PDF(Pubmed)
Abstract：
Cell contractility regulates epithelial tissue geometry development and homeostasis. The underlying mechanobiological regulation circuits are poorly understood and experimentally challenging. We developed an elastomeric pillar cage (EPC) array to quantify cell contractility as a mechanoresponse of epithelial microtissues to substrate stiffness and topography. The spatially confined EPC geometry consisted of 24 circularly arranged slender pillars (1.2 MPa, height: 50 µm; diameter: 10 µm, distance: 5 µm). These high-aspect-ratio pillars were confined at both ends by planar substrates with different stiffness (0.15-1.2 MPa). Analytical modeling and finite elements simulation retrieved cell forces from pillar displacements. For evaluation, highly contractile myofibroblasts and cardiomyocytes were assessed to demonstrate that the EPC device can resolve static and dynamic cellular force modes. Human breast (MCF10A) and skin (HaCaT) cells grew as adherence junction-stabilized 3D microtissues within the EPC geometry. Planar substrate areas triggered the spread of monolayered clusters with substrate stiffness-dependent actin stress fiber (SF)-formation and substantial single-cell actomyosin contractility (150-200 nN). Within the same continuous microtissues, the pillar-ring topography induced the growth of bilayered cell tubes. The low effective pillar stiffness overwrote cellular sensing of the high substrate stiffness and induced SF-lacking roundish cell shapes with extremely low cortical actin tension (11-15 nN). This work introduced a versatile biophysical tool to explore mechanobiological regulation circuits driving low- and high-tensional states during microtissue development and homeostasis. EPC arrays facilitate simultaneously analyzing the impact of planar substrate stiffness and topography on microtissue contractility, hence microtissue geometry and function.
摘要：
细胞收缩性调节上皮组织几何结构发育和稳态。基本的机械生物学调节回路知之甚少，并且在实验上具有挑战性。我们开发了一种弹性柱笼（EPC）阵列，以量化细胞收缩性，作为上皮微组织对底物刚度和形貌的机械响应。空间受限的EPC几何形状由24个圆形排列的细长支柱组成(1.2MPa，高度:50µm;直径:10µm,距离：5µm）。这些高纵横比柱的两端都被具有不同刚度（0.15-1.2MPa）的平面基材限制。解析建模和有限元模拟从支柱位移中获取细胞力。为了评估，评估了高度收缩的肌成纤维细胞和心肌细胞，以证明EPC设备可以解决静态和动态细胞力模式。人乳腺（MCF10A）和皮肤（HaCaT）细胞在EPC几何结构内生长为粘附连接稳定的3D微组织。平面基底区域触发了单层簇的扩散，具有基底刚度依赖性肌动蛋白应力纤维（SF）的形成和大量的单细胞肌动球蛋白收缩性（150-200nN）。在相同的连续微组织中，柱环形貌诱导了双层细胞管的生长。低的有效支柱刚度覆盖了高底物刚度的细胞感知，并诱导了缺乏SF的圆形细胞形状，皮质肌动蛋白张力极低（11-15nN）。这项工作引入了一种通用的生物物理工具，以探索在微组织发育和稳态期间驱动低张力和高张力状态的机械生物学调节电路。EPC阵列有助于同时分析平面基底刚度和形貌对微组织收缩性的影响，因此微组织的几何形状和功能。
