Morphological control of cell fate, behaviour and function

组织的形成关键取决于对特定细胞命运和行为的适当分配。这些竞争性决策的传统观点是，细胞首先感知外部信号暗示，决定它们的命运，然后采取适当的行动(即“决定然后行动”)。然而，我们提出了一种更动态的集体决策“先行动后决定”的观点，该观点利用感觉运动反馈现象来暂时调节选择过程。例如，为了响应信号提示，细胞经常改变形状并延长感知细胞外环境的膜过程(如丝状足突)，将信号受体置于离信号配体越来越近的位置，并产生正反馈。这种感觉运动反馈在几分钟内起作用，而不需要更慢的基因表达变化，因此可能会极大地在时间上调节细胞的决策，并且在机器人和儿童发展中已经是一个广为人知的概念。然而，细胞形状在控制细胞信号、命运和功能中的作用仍未被发掘。为了确定细胞形态和行为之间的动态相互关系，本项目将：(A)探讨细胞形状变化对体内细胞信号动力学的影响。为了探索感觉运动反馈在组织形成协调中的作用，我们将首先测试细胞形态的变化是否与细胞信号动力学中的开关相关。利用脊椎动物血管系统作为模型形态发生系统(由于其高度易处理并与心血管疾病和癌症密切相关)，将使用动态荧光报告器和先进的活体成像方法在斑马鱼胚胎中监测关键的细胞命运决定信号网络。结合血管细胞形态的定量形态计量学分析，我们将独一无二地探索和定义关键细胞形态指标(例如细胞大小、形状、表面积、丝状孢子延伸、细胞-细胞接触)的动态变化与信号网络行为(例如正反馈、信号放大、降噪和振荡)所产生的切换之间的相互关系。(B)确定体内对细胞形态的操纵是否可以指导细胞命运的决定。同时，我们将从功能上测试细胞形状动力学在控制细胞命运和行为方面的作用。我们将利用药理学和/或新的光遗传学方法来操纵细胞形状(例如，调节丝状孔动力学)，探索细胞形态开关对体内血管信号网络动力学、细胞命运和血管形态发生的机制影响。因此，我们将直接测试细胞形状的变化是否在通过感觉运动反馈暂时调节细胞信号和决策方面发挥关键作用；这是一个新的概念，可能被用于治疗心血管疾病和癌症中的病理性血管生长。因此，该项目与BBSRC DTP研究的核心主题密切一致，研究主题包括“世界级支撑生物科学”。此外，该项目将采用高度多学科的方法，不仅利用广泛的核心生物科学技能(跨越分子、细胞、发育和心血管生物学)，还将整合尖端计算和活体生物成像技术，这将开发这些突破性利基研究学科的关键专业知识和新工具。因此，该项目的目标是产生创新的研究工具，并开发多种“新的工作方式”(体内和硅胶内)，以探索控制血管系统中细胞命运、行为和功能的形态机制。

Tissue formation critically depends on the appropriate assignment of specialised cell fates and behaviours. The traditional perspective of these competitive decisions is that cells first perceive extrinsic signalling cues, decide their fate and then act appropriately (i.e. "decide then act"). However, we propose a much more dynamic "act then decide" view of collective decision-making that exploits the phenomenon of sensorimotor-feedback to temporally modulate the selection process. For example, in response to signalling cues, cells often change shape and extend membrane processes (such as filopodia) that perceive the extracellular environment, placing signal receptors ever closer to signal ligand and creating positive-feedback. Such sensorimotor-feedback operates within minutes without necessitating much slower gene expression changes, hence may dramatically temporally modulate cell decision-making, and is already a well-recognised concept in robotics and child development. However, roles for cell shape in the control of cell signalling, fate and function remain unexplored.To define dynamic interrelationships between cell morphology and behaviour, this project will:(a) Probe the impact of cell shape changes on cell signalling dynamics in-vivo. To explore roles for sensorimotor-feedback in the coordination of tissue formation, we will first test if changes in cell morphology correlate with switches in cell signalling dynamics. Using the vertebrate vasculature as a model morphogenetic system (due to its high tractability and close links to cardiovascular disease and cancer), critical cell fate-determining signal networks will be monitored using dynamic fluorescent reporters and advanced in-vivo live imaging approaches in zebrafish embryos. When combined with quantitative morphometric analyses of vascular cell morphology, we will uniquely explore and define interrelationships between dynamic changes in key cell morphological metrics (e.g. cell size, shape, surface area, filopodia extension, cell-cell contacts) and resulting switches in signalling network behaviour (e.g. positive-feedback, signal amplification, noise reduction and oscillations). (b) Determine if in-vivo manipulation of cell morphology can direct cell fate decisions. In parallel, we will functionally test the role of cell shape dynamics in controlling cell fate and behaviour. Using pharmacological and/or novel optogenetic approaches to manipulate cell shape (e.g. modulation of filopodial dynamics), we will explore the mechanistic impact of switches in cell morphology on vascular signalling network dynamics, cell fate and vascular morphogenesis in-vivo. Hence, we will directly test if changes in cell shape play critical roles in temporally modulating cell signalling and decision-making by sensorimotor-feedback; a novel concept that could potentially be exploited therapeutically to tackle pathological vessel growth in cardiovascular disease and cancer. As such, this project closely aligns with the core BBSRC DTP theme of studies encompassing 'world class underpinning biosciences'. Moreover, this project will adopt a highly multidisciplinary approach that not only exploits a broad range of core bioscience skills (spanning molecular, cell, developmental and cardiovascular biology) but also integrates cutting-edge computational and in-vivo live bioimaging techniques that will develop key expertise and novel tools in these ground-breaking niche research disciplines. Thus, this project aims to generate innovative research tools and exploit multiple 'new ways of working' (both in-vivo and in-silico) to explore the morphological mechanisms controlling cell fate, behaviour and function in the vasculature.