Dissecting the mechanism of cell migration at the systems level

项目总结/摘要 细胞迁移是许多重要的生理和病理过程所必需的， 发育、伤口愈合和癌性侵袭。作为一个过程，涉及多方的协调行动， 由于整个细胞长度上的分子集合，细胞迁移不能用 传统的分子方法单独没有考虑在整个细胞的传感，驱动和控制 水平本项目旨在以自上而下的方式将迁移细胞作为一种综合的机械化学 系统基于可能代表复杂的分子网络表现的观察， 交互，我们可以推断底层机器是如何操作的。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。我们将讨论三个重要方面。 首先，我们将询问细胞如何通过称为对称性破缺的过程启动迁移，这导致细胞的迁移。 对称地扩展细胞以启动定向迁移。我们将研究各种各向异性的性质， 作为潜在的对称性破坏线索。此外，丝状伪足作为可能的传感器的功能， 将用成像和药理学方法研究对称性破缺。第二，我们将解决 2D和3D细胞迁移的几个知之甚少的方面。通过长距离跟踪迁移的细胞 在高放大率下，我们期望将新发现的接触跟随过程置于以下背景下： 细胞群体了解细胞形状控制、细胞间相互作用和细胞迁移如何响应3D 环境中，我们将使用3D打印聚丙烯酰胺创建模型系统，并系统地改变 几何和机械参数。然后我们将实验扩展到脱细胞肺支架， 已经用于组织工程，以确定3D中的迁移特性如何与 促进组织形成。另一个被忽视的领域，我们将研究的是尾巴的功能，在定义 细胞极性和介导的接触。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 分别确定拉伸和放松阶段的反应。的组合 计划进行实验和计算机建模，以解释上皮细胞对静态拉伸的反应 沿着力的方向，但垂直地响应于循环拉伸。我们还将测试 假设对周期性拉伸的反应可以引起细胞嵌入，这是一个非常重要的过程， 胚胎形态发生我们希望我们的结果能够补充分子水平的研究， 对基本细胞生物学和组织功能修复的细胞迁移的范式转变见解。

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.