Understanding the control mechanisms of 3D cell migration from new dimensions

细胞在三维组织空间中的迁移对人类生物学具有重要意义。然而，预测和 编程3D细胞运动仍然是主要的挑战，尽管对分子机械的了解很清楚 牵涉其中。填补蛋白质-蛋白质等压倒性亚细胞细节之间的知识空白 相互作用，以及不同类型的细胞在组织空间中展示的迷人的动态模式，我将重点放在 论中尺度细胞动力学，即细胞在三维细胞外基质中的迁移模式转变 (ECM)。我的实验室已经开发了基于深度学习的图像后处理来跟踪细胞的迁移模式。 我们还开发了在细胞尺度上操纵和测量ECM微观力学的技术。基座 根据这些初步结果，我将系统地研究3D细胞的内在和外在控制机制 胶原细胞外基质中迁移模式的转变。这些结果将为我理解长期目标铺平道路。 引导分子存活的组织原理，并为应用于组织中的细胞运动性编程 工程学和癌症治疗。为此，我将把我的实验室奉献给以下研究推动力。推力1 旨在确定细胞迁移模式转换如何受外部提示以及内在状态的调节 在上皮-间充质转化(EMT)过程中细胞的数量。我将测试三个解释这些角色的假设 ECM微观机械硬度、各向异性、可塑性、机械和化学导向的协同作用 随着EMT阶段对细胞迁移模式的调控发生转变。我将采用先进的ECM工程 以及我实验室开发的表征技术。我还将使用基因工程细胞，其EMT 转录因子是荧光标记的，可以被特异地激活。推进器1的完成将确定 三维细胞迁移作为一种隐马尔可夫过程，其中的中尺度动力学，即迁移模式 过渡，提供了一个统一的框架来解释观察到的各种3D细胞迁移的动态模式 活着。推力2旨在设计策略，通过非静止的机械线索来编程细胞迁移。在……里面 子项目1，我将使用我的实验室开发的技术来控制空间和空间中的3D接触指导线索 实时的。通过测量步长递增联系指导下的迁移模式转换，我将获得 分隔不同模式的能量屏障。然后在周期性的机械刺激下，我将测量和 对非平衡模式跃迁通量进行计算建模，这是一个统计物理量，它通知 细胞运动反应的效率和能量消耗。这些中尺度量揭示了 潜在的分子组织原理。在子项目2中，我将开发展示数字化的胶原蛋白ECM 使用DNA接枝纳米颗粒作为交联剂对压力的响应。我会设计DNA序列来控制 交联剂屈服强度，从而编程单个细胞和集体细胞的细胞迁移模式 有机物迁移。推进器2的建成将扩大工程ECM的设计空间，为其奠定基础 用于3D细胞运动的机械编程。

Cell migration in 3D tissue space is of fundamental importance for human biology. However, predicting and programming 3D cell motility remain as major challenges despite of a firm picture of the molecular machineries involved. To fill the knowledge gap between the overwhelming subcellular details such as protein-protein interactions, and the fascinating dynamic patterns exhibited by different cell types in tissue spaces, I will focus on the mesoscale cellular dynamics, namely the migration mode transitions of cells in 3D extracellular matrix (ECM). My lab has developed deep-learning based image postprocessing to track the migration modes of cells. We also developed techniques to manipulate and measure the micromechanics of ECM at cellular scale. Based on these preliminary results, I will systematically study the intrinsic and extrinsic control mechanisms of 3D cell migration mode transitions in collagen ECM. The results will pave the way for my long-term goals to understand the organizing principle that lead molecules to life, and to program cell motility for applications in tissue engineering and cancer treatment. To this end, I will dedicate my lab to the following research thrusts. Thrust 1 aims to determine how cell migration mode transitions are regulated by external cues, as well as intrinsic states of cells during the Epithelial-Mesenchymal Transition (EMT). I will test three hypotheses that elucidate the roles of ECM micromechanical stiffness, anisotropy, plasticity, synergy of mechanical and chemical guidance, as well as EMT stage in modulating the cell migration mode transitions. I will employ sophisticated ECM engineering and characterization techniques developed in my lab. I will also use genetically engineered cells whose EMT transcription factors are fluorescent labeled and can be specifically activated. Completion of thrust 1 will establish 3D cell migration as a hidden Markov process where the mesoscale dynamics, namely the migration mode transitions, provides a unifying framework to explain diverse dynamic patterns of 3D cell migration observed in vivo. Thrust 2 aims to devise strategies to program cell migration via nonstationary mechanical cues. In subproject 1, I will employ techniques developed in my lab to control 3D contact guidance cues in space and in real time. By measuring the migration mode transitions under step-increasing contact guidance, I will obtain the energy barriers that separate different modes. Then under periodic mechanical stimuli I will measure and computationally model the nonequilibrium mode transition flux, a statistical physics quantity that inform the efficiency and energy dissipation of cell motility responses. These mesoscale quantities shed light to the underlying molecular organizing principles. In subproject 2 I will develop collagen ECM which exhibits digital response to stresses using DNA-grafted nanoparticles as crosslinkers. I will design the DNA sequence to control the yield strength of crosslinkers, thereby programing cell migration mode both for single cell and for collective organoid migration. Completion of thrust 2 will expands the design space of engineered ECM, laying a foundation for the mechanical programing of 3D cell motility.