Investigating mechanisms regulating cytoskeletal dynamics and alignment during epithelial tissue folding

研究上皮组织折叠过程中细胞骨架动力学和排列的调节机制

• 批准号: 10229158
• 负责人: Mary Ann Collins
• 金额: $ 6.6万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10229158
• 关键词: Actomyosin; Adherens Junction; Adult; Affect; Apical; Apoptosis; Automobile Driving; Behavior; Cancer Biology; Cell Shape; Cells; Cellular biology; Chemicals; Collection; Congenital Abnormality; Connective Tissue; Cytoskeletal Modeling; Cytoskeleton; Defect; Deformity; Development; Developmental Biology; Disease; Disease Progression; Disputes; Drosophila genus; Drosophila melanogaster; Embryo; Embryonic Development; Epithelial; Event; F-Actin; Failure; Fogs; Gene Expression; Genetic; Goals; Health; Human; Image; Image Analysis; Individual; Intercellular Junctions; Knowledge; Label; Lead; Light; Link; Malignant Neoplasms; Measures; Mechanics; Mesenchymal; Mesoderm; Methods; Microfilaments; Microscopy; Mission; Molecular; Molecular Motors; Morphogenesis; Motor; Movement; Myosin ATPase; Myosin S-2; Myosin Type II; Nature; Neoplasm Metastasis; Neural Tube Defects; Neural tube; Organ; Outcome; Physiologic pulse; Process; Production; Research; Resolution; Role; Seminal; Shapes; Signal Pathway; Signal Transduction; Structure; Surface; TWIST1 gene; Testing; Tissues; United States National Institutes of Health; Work; alpha catenin; base; comparative; constriction; crosslink; developmental disease; driving force; epithelial to mesenchymal transition; gastrulation; imaging modality; innovation; insight; intercellular connection; mechanical force; mutant; myosin phosphatase; non-muscle myosin; novel; physical property; predictive modeling; prevent; quantitative imaging; single molecule; training opportunity; transmission process; tumor progression

Project Summary: Large-scale tissue movements are critical during development to transform an amorphous collection of cells into organs with specific structure and function. Abnormal activation of force-generating signals that regulate epithelial morphogenesis can result in developmental defects, such as neural tube deformities, as well as aberrant epithelial-mesenchymal transition and cancer metastasis. Yet we do not fully understand how mechanical forces generated at the molecular level regulate epithelial remodeling. At the cellular level, most forces are generated by the actomyosin network; the molecular motor non-muscle myosin II (myosin) crosslinks actin filaments (F-actin), thereby generating contractile forces which are propagated throughout the tissue via intercellular connections. One outcome of actomyosin contractility is apical contraction, in which the apex of the cell narrows as a result of repeated bursts of myosin pulses that condense the F-actin cortex in a ratchet-like manner. When myosin pulsing and ratcheting is disrupted, cells fail to apically constrict and the tissue fails to fold. However, the mechanisms driving pulsatile contractions and ratcheting behavior remains poorly understood, highlighting a critical gap in our understanding of how upstream signaling events are intricately linked to downstream changes in cytoskeletal organization and behavior. The long-term goal of this project is to determine how mechanical forces generated at the molecular level collectively drive tissue-wide morphogenetic changes. The overall objective of this proposal is to identify mechanisms that regulate myosin dynamics and alignment by determining the mechanistic link between Twist expression and myosin turnover. The rationale for this proposed work is to gain insight not only into the nature of these mechanisms, but also the general principles governing contractility and ratchet-like apical constriction during large-scale tissue movements. Our central hypothesis is that Twist, and its downstream effectors, as well as tissue-wide forces, via intercellular connections, cooperatively regulate myosin dynamics to drive apical ratcheting and tissue remodeling events during embryonic development in Drosophila. This hypothesis will be tested by pursuing two specific aims: we will (1) determine the mechanism through which Twist promotes cell apex stabilization, and (2) determine how myosin dynamics are affected by intercellular connectivity. Our approach is innovative because it is one of the first to directly examine myosin dynamics using an integrative strategy that combines classic Drosophila genetics with advanced microscopy methods, including photo-conversion and super- resolution imaging. The proposed research is significant because it will advance our understanding of the connection between gene expression, signaling pathways, and force production during epithelial morphogenesis, and will provide new perspective to ongoing research efforts investigating developmental diseases and cancer biology.

项目摘要： 大规模组织运动在开发过程中至关重要，以转化无定形的集合 细胞进入具有特定结构和功能的器官。力产生信号的异常激活 调节上皮形态发生会导致发育缺陷，例如神经管畸形， 作为异常上皮 - 间质转变和癌症转移。但是我们不完全了解如何 在分子水平上产生的机械力调节上皮重塑。在细胞水平上，大多数 力是由Actomyosin网络产生的；分子运动非肌肉肌球蛋白II（肌球蛋白） 交叉链接肌动蛋白丝（F-肌动蛋白），从而产生了收缩力，这些力量在整个过程中传播 通过细胞间连接组织。肌动蛋白收缩力的一个结果是根尖收缩，其中 细胞的顶点因反复的肌球蛋白脉冲的重复爆发而变窄，肌球蛋白脉冲将F-肌动蛋白皮质凝结在一个 类似棘轮的方式。当肌球蛋白脉动和棘轮被破坏时，细胞无法缩减，并且 组织无法折叠。但是，驱动脉动收缩和棘轮行为的机制仍然存在 理解不佳，强调了我们对上游信号事件的理解的关键差距 与细胞骨架组织和行为的下游变化相关。这个长期目标 项目将确定在分子水平上如何共同驱动组织的机械力如何产生 形态发生变化。该提案的总体目的是确定调节肌球蛋白的机制 通过确定扭曲表达和肌球蛋白周转之间的机械联系，动力学和对齐。 这项拟议工作的理由是，不仅要洞悉这些机制的本质，而且还要了解 大规模组织期间的收缩性和类似棘轮的顶部收缩的一般原则 动作。我们的中心假设是扭曲及其下游效应子以及整个组织的力量， 通过细胞间连接，协同调节肌球蛋白动力学以驱动顶棘和组织 果蝇胚胎发育期间的重塑事件。该假设将通过追求两个来检验 具体目的：我们将（1）确定扭曲促进细胞顶点稳定的机制，并确定 （2）确定肌球蛋白动力学如何受细胞间连通性的影响。我们的方法是创新的 因为它是最早使用组合的集成策略直接检查肌球蛋白动力学的人之一 具有晚期显微镜方法的经典果蝇遗传学，包括光转换和超级 - 分辨率成像。拟议的研究很重要，因为它将提高我们对 上皮期间基因表达，信号通路和力产生之间的联系 形态发生，并将为正在进行的研究工作提供新的观点 疾病和癌症生物学。