Dissecting the mechanism of cell migration at the systems level

项目摘要/摘要 细胞迁移是许多重要的生理和病理过程所必需的，如胚胎 发展、伤口愈合和癌症侵袭。作为一个涉及多个因素协同行动的过程 在整个细胞长度上的分子集合，细胞迁移不能用 传统的分子方法没有考虑整个细胞的感知、驱动和控制 水平。这个项目寻求以自上而下的方式将细胞迁移作为一种综合的机械力化学方法。 系统。基于可能代表复杂的分子网络表现形式的观察 相互作用，我们可以推断底层机器是如何运行的。该项目将由 开发新技术，包括聚丙烯酰胺水凝胶的3D打印和机器学习 细胞跟踪、牵引力显微镜和超分辨率成像。我们将解决三个重要方面。 首先，我们将询问细胞如何通过一个称为对称性破缺的过程启动迁移，这一过程导致 对称地散布细胞以启动定向迁移。我们将研究各种各向异性属性 衬底作为潜在的对称性破缺线索。此外，丝状伪足作为可能的感受器的功能 对称性破缺将通过成像和药理学方法进行研究。第二，我们将解决 2D和3D细胞迁移的几个鲜为人知的方面。通过远距离跟踪迁移的细胞 在高倍率下，我们希望将新发现的接触过程放在 细胞集体。了解细胞形状控制、细胞间相互作用和细胞迁移对3D的响应 环境，我们将使用3D打印的聚丙烯酰胺来创建模型系统，并系统地进行变化 几何和力学参数。然后我们将把实验扩展到脱细胞的肺支架， 已被用于组织工程，以确定3D中的迁移特征如何与 促进组织形成。我们将研究的另一个被忽视的领域是尾部在定义 随之而来的是细胞极性和中介接触。第三，我们将寻求对细胞的机械理解 对周期性拉伸的反应，这种反应发生在各种组织中。一种新的成像方法将使我们能够 分别确定伸展和放松阶段的反应。一种组合 计划进行实验和计算机建模，以解释为什么上皮细胞对静态拉伸做出反应 顺向力的方向，但垂直于循环拉伸。我们还将测试 假设对循环拉伸的反应可以导致细胞嵌入，这是 胚胎形态发生。我们预计我们的结果将在分子水平上补充研究，并带来 改变对细胞迁移的基本细胞生物学和组织功能修复的洞察力。

Project Summary/Abstract Cell migration is required for many important physiological and pathological processes such as embryonic development, wound healing, and cancerous invasion. As a process that involves concerted action of multiple ensembles of molecules over the length of the entire cell, cell migration cannot be understood using conventional molecular approaches alone without considering sensing, actuation, and control at the whole cell level. This project seeks to approach migrating cells in a top-down manner as an integrated mechanochemical system. Based on observations that likely represent the manifestation of a complex network of molecular interactions, we may deduct how the underlying machine operates. The project will be facilitated by the development of new technologies, including 3D printing of polyacrylamide hydrogels and machine learning for cell tracking, traction force microscopy, and super resolution imaging. We will address three important aspects. First, we will ask how cells initiate migration through a process known as symmetry breaking, which causes a symmetrically spreading cell to initiate directional migration. We will examine various anisotropic properties of the substrate as potential symmetry breaking cues. In addition, the function of filopodia as possible sensors for symmetry breaking will be studied with imaging and pharmacological approaches. Second, we will address several poorly understood aspects of 2D and 3D cell migration. By following migrating cells over a long distance at a high magnification, we expect to place the newly discovered process of contact following in the context of cell collectives. To understand how cell shape control, cell-cell interaction, and cell migration respond to 3D environment, we will use 3D printed polyacrylamide to create model systems and systematically vary geometrical and mechanical parameters. We will then extend the experiments to decellularized lung scaffolds, which have been used for tissue engineering, to determine how migration characteristics in 3D is related to the promotion of tissue formation. Another overlooked area we will examine is the function of the tail in defining cell polarity and mediating contact following. Third, we will seek mechanistic understanding of cellular responses to cyclic stretching, which occurs in various tissues. A novel imaging approach will allow us to determine the responses during the stretching and relaxation phase respectively. A combination of experimentation and computer modeling is planned to explain why epithelial cells respond to static stretching along the direction of forces but perpendicularly in response to cyclic stretching. We will also test the hypothesis that responses to cyclic stretching can cause cell intercalation, a fundamentally important process in embryonic morphogenesis. We expect our results to complement studies at the molecular level and bring paradigm shifting insights into cell migration for both basic cell biology and repair of tissue functions.