Investigating mechanisms regulating cell adhesion during tissue remodeling

研究组织重塑过程中调节细胞粘附的机制

• 批准号: 10229401
• 负责人: Donald Nathaniel Clarke
• 金额: $ 6.86万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10229401
• 关键词: Adherens Junction; Adhesions; Adult; Affect; Affinity; Animal Model; Apical; Automobile Driving; Behavior; Behavior monitoring; Biochemical; Biological; Cadherins; Cancer Biology; Cell Adhesion; Cell Adhesion Molecules; Cell-Cell Adhesion; Cells; Cellular biology; Cessation of life; Complex; Congenital Disorders; Data; Defect; Development; Disease; Dorsal; Drosophila genus; Drosophila melanogaster; E-Cadherin; Ectopic Expression; Embryo; Embryonic Development; Epithelial; Event; Failure; Fogs; Gene Silencing; Genes; Genetic; Genetic Transcription; Geometry; Germ Layers; Goals; Health; Homeostasis; Human; Image; Intercellular Junctions; Knowledge; Link; Malignant Neoplasms; Mass Screening; Mass Spectrum Analysis; Mesenchymal; Mission; Modeling; Morphogenesis; Nature; Neoplasm Metastasis; Outcome; Pathway interactions; Post-Transcriptional Regulation; Post-Translational Protein Processing; Process; Proteins; Proteomics; RNA Interference; Regulation; Repression; Research; Role; Signal Transduction; Snails; Subcellular structure; System; Testing; Tissues; Transcriptional Regulation; United States National Institutes of Health; Work; base; beta catenin; cancer cell; cell behavior; cell motility; comparative; constriction; embryo tissue; fly; gastrulation; gene repression; innovation; insight; knock-down; nanobodies; novel; physical property; physical state; protein complex; segregation; training opportunity; transcription factor; tumor

Project Summary: Precise control of cell-cell adhesion is critical for maintaining tissue integrity during development and in adult tissues. Abnormal activation of signals that regulate adhesion in tumors can result in epithelial-mesenchymal transition (EMT) and cancer metastasis, but we do not fully understand the mechanism through which these regulatory signals cause loss of adhesion. A proposed model for this process is transcriptional repression of cell adhesion genes: the EMT regulator Snail represses expression of the E- cadherin adhesion molecule, a core component of Adherens Junctions (AJs), and is thought to control adhesion in this manner. However, recent observations have shown that Snail regulates the stability and localization of AJs independent of transcriptional regulation of E-Cadherin levels. The specific mechanism by which Snail regulates AJ organization remains unknown, highlighting an important gap in our understanding of the signals that regulate adhesion and govern the cellular decision to undergo EMT. The long-term goal of this project is to determine how cell-cell adhesion is controlled during development to enable tissue morphogenesis and segregation of germ layers. The overall objective of this proposal is to identify mechanisms by which Snail regulates AJ organization during tissue remodeling events during embryonic development in Drosophila, and determine how this regulation contributes to a cell’s decision to undergo EMT. Preliminary data indicate that ectopic Snail expression causes a rapid shift in E-Cadherin protein localization from cell junctions to intracellular structures. Other observations have shown that cells in the Drosophila ventral furrow undergo junctional remodeling through Snail-dependent destabilization of AJs. Remarkably, this regulation occurs prior to depletion of maternally provisioned E-Cadherin protein, and is not inhibited by ectopic E-cadherin expression. Together these data indicate that Snail controls AJ organization through an additional post- transcriptional mechanism. The rationale for this proposed work is to gain insight not only into the nature of these mechanisms, but also the general principles governing cell adhesion during EMT events. Our central hypothesis is that Snail modulates adhesion by altering the stability and localization of junctional cadherin protein complexes through a mechanism independent of E-cadherin transcriptional regulation. This hypothesis will be tested by pursuing two specific aims: we will (1) identify the mechanism through which Snail affects AJ organization, and (2) define the physical conditions in which Snail can promote EMT in Drosophila epithelial tissues. Our approach is innovative because it is one of the first to examine the mechanistic basis of Snail- dependent shifts in cadherin localization, and further because it uses an integrative strategy that combines biochemical and cell biological approaches. The proposed research is significant because it is expected to advance our understanding of the post-transcriptional regulation of cell-cell adhesion, and may open new avenues of research for understanding cancer biology and developmental defects.

项目摘要：细胞间粘附的精确控制对于维持组织完整性至关重要 发育和成人组织中。调节肿瘤粘附的信号异常激活可能导致 上皮间质转化（EMT）和癌症转移，但我们并不完全了解其机制 这些调节信号通过这些信号导致粘附力丧失。该过程的建议模型是 细胞粘附基因的转录抑制：EMT 调节因子 Snail 抑制 E- 的表达 钙粘蛋白粘附分子是粘附连接 (AJ) 的核心成分，被认为可以控制 以这种方式粘合。然而，最近的观察表明，Snail 调节稳定性和 AJ 的定位独立于 E-钙粘蛋白水平的转录调节。具体机制由 Snail 监管 AJ 组织的方式仍不得而知，这突显了我们对 AJ 组织的理解存在重要差距 调节粘附和控制细胞决定进行 EMT 的信号。本次活动的长远目标 该项目是确定在发育过程中如何控制细胞间粘附以实现组织形态发生 和胚层的分离。该提案的总体目标是确定 Snail 的机制 在果蝇胚胎发育过程中的组织重塑事件中调节 AJ 组织，以及 确定这种调节如何影响细胞决定进行 EMT。初步数据表明 异位 Snail 表达导致 E-钙粘蛋白定位从细胞连接处快速转变为 细胞内结构。其他观察结果表明，果蝇腹沟中的细胞经历了 通过 AJ 的 Snail 依赖性不稳定进行连接重塑。值得注意的是，该规定发生在 消耗母体提供的 E-钙粘蛋白，并且不受异位 E-钙粘蛋白抑制 表达。这些数据共同表明，Snail 通过额外的后置控制 AJ 组织。 转录机制。这项拟议工作的基本原理是不仅要深入了解 这些机制，也是 EMT 事件期间控制细胞粘附的一般原则。我们的中央 假设 Snail 通过改变连接钙粘蛋白的稳定性和定位来调节粘附 通过独立于 E-钙粘蛋白转录调控的机制来形成蛋白质复合物。这个假设 将通过追求两个具体目标进行测试：我们将 (1) 确定 Snail 影响 AJ 的机制 (2) 定义 Snail 促进果蝇上皮细胞 EMT 的物理条件 组织。我们的方法是创新的，因为它是第一个研究 Snail 机制基础的方法之一。 钙粘蛋白定位的依赖性转变，并且进一步因为它使用了结合的综合策略 生物化学和细胞生物学方法。拟议的研究意义重大，因为预计 增进我们对细胞间粘附转录后调控的理解，并可能开辟新的领域 了解癌症生物学和发育缺陷的研究途径。