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

基本信息

批准号：
10598503
负责人：
Mary Ann Collins
金额：
$ 7.18万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
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/10598503
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 Dedications Defect Deformity Development Developmental Biology Disease Disease Progression Disputes Drosophila genus Drosophila melanogaster Embryo Embryonic Development Epithelium Event F-Actin Failure Fogs Gene Expression Genetic Goals Health Human Image Image Analysis Individual Intercellular Junctions Knowledge Label 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 Role Seminal Shapes Signal Pathway Signal Transduction Structure Surface TWIST1 gene Testing Tissues United States National Institutes of Health Work alpha catenin behavior prediction comparative constriction crosslink developmental disease driving force epithelial to mesenchymal transition gastrulation imaging modality innovation insight intercellular connection mechanical force mechanical signal mutant myosin phosphatase non-muscle myosin novel physical property predictive modeling prevent quantitative imaging single molecule superresolution imaging superresolution microscopy training opportunity transmission process tumor progression

项目摘要

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.

项目概要：在发育过程中，大规模的组织运动对于转变无定形的集合至关重要细胞分化为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也会导致发育缺陷，例如神经管畸形如异常的上皮间质转化和癌症转移。然而我们还不完全明白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，大多数力由肌动球蛋白网络产生；分子运动非肌肉肌球蛋白 II（肌球蛋白）交联肌动蛋白丝（F-肌动蛋白），从而产生收缩力，并在整个肌动蛋白中传播组织通过细胞间连接。肌动球蛋白收缩性的结果之一是心尖收缩，其中由于肌球蛋白脉冲的重复爆发，将 F-肌动蛋白皮层浓缩在一个棘轮式方式。当肌球蛋白脉冲和棘轮作用被破坏时，细胞无法进行顶部收缩，并且组织无法折叠。然而，驱动脉动收缩和棘轮行为的机制仍然存在理解甚少，凸显了我们对上游信号事件如何理解的关键差距与细胞骨架组织和行为的下游变化密切相关。本次活动的长远目标该项目旨在确定分子水平上产生的机械力如何共同驱动组织范围内的机械力形态发生的变化。该提案的总体目标是确定调节肌球蛋白的机制通过确定 Twist 表达和肌球蛋白周转之间的机制联系来确定动力学和排列。这项拟议工作的基本原理是不仅要深入了解这些机制的本质，而且要深入了解这些机制的本质。控制大范围组织收缩性和棘轮状顶端收缩的一般原则动作。我们的中心假设是 Twist 及其下游效应器以及组织范围的力，通过细胞间连接，协同调节肌球蛋白动力学以驱动顶端棘轮和组织果蝇胚胎发育过程中的重塑事件。这个假设将通过追求两个具体目标：我们将 (1) 确定 Twist 促进细胞顶端稳定的机制，以及 (2)确定肌球蛋白动力学如何受到细胞间连接的影响。我们的方法是创新的因为它是第一个使用综合策略直接检查肌球蛋白动态的系统之一，该策略结合了经典的果蝇遗传学与先进的显微镜方法，包括光转换和超级分辨率成像。拟议的研究意义重大，因为它将增进我们对上皮细胞过程中基因表达、信号通路和力产生之间的联系形态发生，并将为正在进行的发育研究工作提供新的视角疾病和癌症生物学。