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: 10001978
• 负责人: Donald Nathaniel Clarke
• 金额: $ 6.53万
• 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/10001978
• 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; Epithelium; 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.

项目总结：精确控制细胞-细胞粘附对于维持组织完整性至关重要。 发育和成人组织中。调节肿瘤中粘附的信号的异常激活可导致 上皮间质转化（EMT）和癌症转移，但我们并不完全了解其机制 这些调节信号通过其引起粘附的丧失。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- 钙粘蛋白粘附分子，粘附连接（AJs）的核心成分，被认为是控制 以这种方式粘合。然而，最近的观察表明，蜗牛调节稳定性， AJs的定位独立于E-钙粘蛋白水平的转录调节。具体机制由 蜗牛管理AJ组织仍然是未知的，突出了我们对AJ组织的理解中的一个重要空白。 调节粘附和支配细胞决定进行EMT的信号。长期目标是 该项目的目的是确定在发育过程中如何控制细胞间的粘附，以使组织形态发生 以及胚层的分离。本提案的总体目标是确定Snail 在果蝇胚胎发育期间的组织重塑事件中调节AJ组织， 确定这种调节如何有助于细胞决定进行EMT。初步数据表明 异位Snail表达导致E-Cadherin蛋白定位从细胞连接处迅速转移到 细胞内结构其他的观察表明果蝇腹沟中的细胞经历了 通过依赖Snail的AJs失稳的连接重塑。值得注意的是，这一规定发生在 消耗母体提供的E-钙粘蛋白，并且不受异位E-钙粘蛋白的抑制 表情总之，这些数据表明，蜗牛控制AJ组织通过一个额外的后， 转录机制这项拟议工作的理由是，不仅要深入了解 这些机制，但也在EMT事件的细胞粘附的一般原则。我们的中央 有一种假说认为Snail通过改变连接性钙粘蛋白的稳定性和定位来调节粘附 蛋白复合物通过独立于E-钙粘蛋白转录调控的机制。这一假设 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 组织，以及（2）定义蜗牛可以促进果蝇上皮细胞EMT的物理条件 组织中我们的方法是创新的，因为它是第一个检查蜗牛的机械基础- 依赖性的钙粘蛋白定位的变化，并进一步因为它使用了一种整合策略， 生物化学和细胞生物学方法。这项研究意义重大，因为它有望 推进我们对细胞间粘附的转录后调节的理解，并可能开辟新的 了解癌症生物学和发育缺陷的研究途径。