Mechanical Regulation of Cell Adhesion by Dynamic Cytoskeletal Assemblies - Resubmission 01

 描述(申请人提供)：细胞黏附和形态由动态细胞骨架组件调节，该组件介导力在细胞和周围环境中的传递。细胞力生成和黏附的时空调控驱动着细胞迁移、组织形态发生和细胞外基质重塑等多种生理过程中的形态发生变化。虽然在理解细胞黏附和力产生的分子机制方面已经取得了重大进展，但我们缺乏一个框架来理解黏附斑块和肌动蛋白细胞骨架的复杂生物物理行为是如何从细胞骨架蛋白的动态集合中产生的。我们假设，了解黏附斑块和肌动蛋白细胞骨架内的力传递将为将分子机制转化为细胞复杂的物理行为提供必要的见解。我们提出的实验将阐明通过局灶性粘连、细胞间粘连和肌动蛋白细胞骨架的力传递机制，以及这些机制是如何协调来调节多细胞组织中的力传递的。我们通过将分子细胞生物学方法与先进的细胞骨架动力学定量成像和生物物理测量相结合来解决这个问题。通过获得蛋白质在不同张力水平下的运动学和运动学(运动)特征，我们确定了局部粘连和肌动蛋白细胞骨架中的力传递机制。然后，我们与理论物理学家密切合作，用我们的定量生物物理测量来测试分析理论和模拟的预测。这项工作建立了对细胞黏附、张力和形状的物理学的定量理解，最终将为细胞迁移和组织形态发生的理论和模型提供框架，这些理论和模型将在理解复杂的生理过程中具有预测能力。通过在这些目标中获得的知识，我们将确定细胞-ECM和细胞-细胞黏附之间的机械耦合在控制多细胞组织中的形态重排中的作用。这将使改进的治疗方法得以开发，以治疗涉及组织稳态的疾病，目前仅通过治疗分子靶点仍难以捉摸这些疾病。

 DESCRIPTION (provided by applicant): Cell adhesion and morphology are regulated by dynamic cytoskeletal assemblies that mediate force transmission across the cell and to the surrounding environment. Spatiotemporal regulation of cellular force generation and adhesion drive morphogenic changes in diverse physiological processes including cell migration, tissue morphogenesis and ECM remodeling. While significant progress has been made to understand the molecular mechanisms of cell adhesion and force generation, we lack a framework to understand how the complex biophysical behaviors of adhesion plaques and the actin cytoskeleton emerge from dynamic ensembles of cytoskeletal proteins. We hypothesize that understanding force transmission within adhesion plaques and the actin cytoskeleton will provide the necessary insight to translate molecular mechanisms to complex physical behaviors of cells. We propose experiments that will elucidate mechanisms of force transmission through focal adhesions, cell-cell adhesions and the actin cytoskeleton and how these are coordinated to regulate force transmission in multicellular tissue. We approach this problem by integrating molecular cell biology approaches with advanced quantitative imaging of cytoskeletal dynamics and biophysical measurements. By obtaining kinetic and kinematic (motion) signatures of proteins at varying levels of tension, we identify mechanisms of force transmission within focal adhesions and the actin cytoskeleton. We then collaborate closely with theoretical physicists to test the predictions of analytical theory and simulations with our quantitative biophysical measurements. This work builds a quantitative understanding of the physics of cell adhesion, tension and shape that, ultimately, will provide the framework for theories and models of cell migration and tissue morphogenesis that will have predictive power in understanding complex physiological processes. Through knowledge gained in these aims, we will identify the role of mechanical coupling between cell-ECM and cell-cell adhesions in controlling morphological rearrangements in multi-cellular tissue. This will enable the development of improved therapies to treat diseases involved in tissue homeostasis that currently remain elusive by solely treating molecular targets.