Optogenetic control of cell behaviour (MechanoSwitch)

细胞在复杂环境中的决策依赖于生化和机械信号。现在已经确定，贴壁细胞产生机械力来感知其环境的粘连几何形状和刚性，从而对迁移、分化和命运产生戏剧性的影响。通常，细胞对刚度的响应是在静态环境中研究的，例如，通过测量细胞牵引力和在可变刚度的弹性衬底上的机械传递。然而，当细胞与其环境在动态环境中相互作用时，刚性感知如何发挥作用还不是很清楚，尽管这是发育、伤口愈合或转移的标准情况。机械开关项目将利用光遗传学的最新进展来揭示活细胞如何以动态的方式利用它们的触觉，以及细胞行为如何受光控制。我们将使用光学显微镜实时成像细胞组织，使用软弹性底物和牵引力显微镜连续监测细胞力，并使用光遗传学动态改变细胞的收缩状态。细胞组织和迁移的数学模型将首先由实验数据参数化，然后用于设计新一轮实验。通过预测光遗传学的适当光照模式，我们计划在复杂的环境中引导细胞。

Cellular decision-making in complex environments depends on both biochemical and mechanical signals. It is now well established that adherent cells generate mechanical forces to sense the adhesive geometry and rigidity of their environment, with dramatic consequences for migration, differentiation and fate. Usually the cellular response to stiffness is studied in a static context, for example by measuring cellular traction forces and mechanotransduction on elastic substrates of variable stiffness. It is however less clear how rigidity sensing works when cells and their environment interact in a dynamical context, although this is the standard case in development, wound healing or metastasis. The MechanoSwitch project will use recent advances in optogenetics to unravel how living cells use their sense of touch in a dynamical way and how cell behaviour can be controled by light. We will use optical microscopy to live-image cell organization, soft elastic substrates and traction force microscopy to continuously monitor cell forces, and optogenetics to dynamically change the contractile status of the cell. Mathematical models for cell organization and migration will be first parametrized by the experimental data and then used to design the new round of experiments. By predicting the appropriate illumination patterns for optogenetics, we plan to steer cells in complex environments.