Mechanisms of collective cell movement during embryonic heart development

胚胎心脏发育过程中集体细胞运动的机制

• 批准号: RGPIN-2019-06152
• 负责人: FernandezGonzalez, Rodrigo
• 金额: $ 3.64万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=746043
• 关键词: Mechanisms; collective; cell; movement; during

An outstanding question in biology is how cells coordinate their movements. Coordinated cell movements drive tissue development and repair, and also cause disease. A common feature of collective cell movements is the generation and transmission of mechanical forces. My research program develops novel quantitative microscopy and biophysical methods with the long-term objective of establishing the physical and molecular signals that coordinate cell behaviours in living animals. Our short-term goal for this proposal is to determine the mechanisms of cell movement and coordination during the early stages of heart development in the fruit fly Drosophila melanogaster. Heart development in vertebrates and invertebrates begins with the collective migration of two groups of cells from opposite sides of the embryo to form a tube. We use heart tube formation in Drosophila to model collective cell migration, as it is a stereotypical process involving two rows of 52 cardiac progenitors (cardioblasts) each, and it allows live imaging and genetic, pharmacological, and biophysical manipulations. We discovered that the movement of cardioblasts is not continuous, but rather consists of periodic steps forward. Importantly, we found that dynamic cytoskeletal protein networks flow periodically between the front and the back of each cardioblast, with each cycle corresponding with a cell step. In addition, we found a supracellular cable formed by the cytoskeletal protein actin and spanning the 52 cardioblasts in each row as they migrate. However, the mechanisms that govern cytoskeletal flows and cables, and the contributions of these networks to collective cell migration remain unclear. Here, we will (1) establish the role of dynamic cytoskeletal flows in cardioblast migration, and (2) define the contribution of the supracellular actin cable to collective cardioblast movements. To accomplish these aims, we will (3) develop quantitative microscopy, image analysis, and machine learning tools to monitor subcellular and supracellular cytoskeletal networks with high spatial and temporal resolution. Our tools will automate and thus accelerate the analysis of the images obtained, and will minimize human bias in the analysis. Our studies will reveal the mechanisms that control collective cell migration during heart tube formation in Drosophila. We will characterize a new mode of flow-driven cell movement, and a novel supracellular actin network that coordinates cardiac progenitor migration. The signals that regulate cytoskeletal dynamics are conserved across tissues and species. Thus, our findings will have direct implications for the general understanding of collective cell behaviours. Importantly, a group of talented trainees will also benefit from our research by receiving interdisciplinary training in cell and molecular biology, genetics, microscopy, image analysis and data science, all skills in high demand both in academic and industry settings.

生物学中一个突出的问题是细胞如何协调它们的运动。协调的细胞运动驱动组织发育和修复，也会导致疾病。集体细胞运动的一个共同特征是机械力的产生和传递。我的研究项目开发了新的定量显微镜和生物物理方法，其长期目标是建立协调活体动物细胞行为的物理和分子信号。我们的短期目标是确定果蝇心脏发育早期细胞运动和协调的机制。脊椎动物和无脊椎动物的心脏发育始于两组细胞从胚胎的相对两侧集体迁移形成一个管。我们使用果蝇中的心管形成来模拟集体细胞迁移，因为它是一个典型的过程，每个过程涉及两排52个心脏祖细胞（成心细胞），并且它允许实时成像和遗传，药理学和生物物理学操作。我们发现，成心细胞的运动不是连续的，而是由周期性的前进步骤组成。重要的是，我们发现动态的细胞骨架蛋白网络在每个成心脏细胞的前部和后部之间周期性地流动，每个周期对应于一个细胞步骤。此外，我们还发现了一个由细胞骨架蛋白肌动蛋白形成的细胞上的电缆，当它们迁移时，它跨越了每一行中的52个成心细胞。然而，支配细胞骨架流动和电缆的机制，以及这些网络对集体细胞迁移的贡献仍不清楚。在这里，我们将（1）建立动态细胞骨架流动在成心细胞迁移中的作用，（2）确定细胞外肌动蛋白电缆对集体成心细胞运动的贡献。为了实现这些目标，我们将（3）开发定量显微镜，图像分析和机器学习工具，以高空间和时间分辨率监测亚细胞和超细胞细胞骨架网络。我们的工具将自动化，从而加速对所获得的图像的分析，并将最大限度地减少分析中的人为偏见。我们的研究将揭示果蝇心管形成过程中控制集体细胞迁移的机制。我们将描述一种新的流动驱动的细胞运动模式，以及一种新的协调心脏祖细胞迁移的细胞外肌动蛋白网络。调节细胞骨架动力学的信号在组织和物种中是保守的。因此，我们的发现将对集体细胞行为的一般理解产生直接影响。重要的是，一群有才华的学员也将从我们的研究中受益，他们将接受细胞和分子生物学，遗传学，显微镜，图像分析和数据科学等跨学科培训，这些技能在学术和行业环境中都有很高的需求。