Regulation of Extracellular Matrix Assembly at the Myotendinous Junction

肌腱连接处细胞外基质组装的调节

基本信息

批准号：
8446096
负责人：
Thomas F Schilling
金额：
$ 19.61万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-03-01 至 2015-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8446096
关键词：
Address Adhesions Adhesives Aging Behavior Collagen Type I Complex Connective Tissue Cytoskeleton Defect Development Disease Drosophila genus Dystrophin Embryo Extracellular Matrix Extracellular Matrix Proteins Fluorescence Fluorescence Microscopy Genes Genetic Genetic Transcription Goals Human Human Development Image In Vitro Integrin Binding Integrins Label Life Ligaments Ligands Link Maintenance Measures Mechanics Methods Microscopy Modeling Morphogenesis Movement Mus Muscle Muscle Contraction Muscular Dystrophies Musculoskeletal System Myoblasts Optics Pharmacological Treatment Physiological Physiology Process Production Proteins Regulation Reporting Research Role Signal Transduction Site Specific qualifier value Spectrum Analysis Stem cells Structure Surface Technology Tendon Injuries Tendon structure Testing Time To specify Transgenic Organisms Ursidae Family Zebrafish congenital muscular dystrophy effective therapy genetic manipulation in vivo interest microstimulation mutant novel paxillin progenitor public health relevance repaired scaffold scleraxis stem thrombospondin 4 tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): The formation of myotendinous junctions (MTJs) is a fundamental component of a functional musculoskeletal system. Muscles interact with tendons at their attachment sites, causing a reorganization of the extracellular matrix (ECM) into connective tissue structures that can bear the large forces exerted by muscle contraction. The transcription factor Scleraxis (Scx) specifies early tendon progenitors and regulates ECM production, and we recently discovered an ECM protein called Thrombospondin-4b (Thbs4b) in zebrafish that is regulated by Scx and required for muscle attachment. How tendon progenitors reach sites of muscle attachment and influence ECM assembly and muscle adhesion at the MTJ remains unclear. The current proposal addresses these issues using the advantages of the zebrafish for in vivo imaging and genetic manipulation. The long-term goal of the proposed research is to understand the spatial dynamics of ECM assembly and Integrin (Itg) signaling at MTJs. Two primary hypotheses guide the research: 1) Scx controls tenocyte specification and ECM production that reorganize Itg signaling components at MTJs, and 2) Thbs4 is a critical Itg ligand in the ECM that acts as a scaffold for other matrix proteins during the formation of MTJs. Aim 1 is to visualize tendon precursors in living zebrafish embryos and study roles for Scx in ECM production and reorganization at MTJs. The optical clarity of zebrafish makes them uniquely suited for this study. Aim 2 analyzes Thbs4b functions in MTJ formation, by altering its expression and analyzing the spatial dynamics of ECM proteins and Itg signaling. Each aim combines novel genetic manipulation, fluorescence dynamics imaging and quantitative methods for physiological stimulation of muscles to get at the mechanisms of ECM assembly at the MTJ.

描述（由申请人提供）：肌腱连接（MTJ）的形成是功能性肌肉骨骼系统的基本组成部分。肌肉在其附着部位与肌腱相互作用，导致细胞外基质（ECM）重组为结缔组织结构，可以承受肌肉收缩所施加的巨大力量。转录因子 Scleraxis (Scx) 指定早期肌腱祖细胞并调节 ECM 产生，我们最近在斑马鱼中发现了一种称为 Thrombospondin-4b (Thbs4b) 的 ECM 蛋白，它受 Scx 调节并且是肌肉附着所必需的。肌腱祖细胞如何到达肌肉附着部位并影响 ECM 组装和 MTJ 处的肌肉粘附仍不清楚。当前的提案利用斑马鱼在体内成像和基因操作方面的优势来解决这些问题。本研究的长期目标是了解 MTJ 处 ECM 组装和整合素 (Itg) 信号传导的空间动态。两个主要假设指导了这项研究：1) Scx 控制肌腱细胞规格和 ECM 产生，从而重组 MTJ 上的 Itg 信号成分；2) Thbs4 是 ECM 中关键的 Itg 配体，在 MTJ 形成过程中充当其他基质蛋白的支架。目标 1 是可视化活体斑马鱼胚胎中的肌腱前体，并研究 Scx 在 ECM 产生和 MTJ 重组中的作用。斑马鱼的光学清晰度使它们特别适合这项研究。目标 2 通过改变 Thbs4b 的表达并分析 ECM 蛋白和 Itg 信号传导的空间动态来分析 Thbs4b 在 MTJ 形成中的功能。每个目标都结合了新颖的基因操作、荧光动力学成像和肌肉生理刺激的定量方法，以了解 MTJ 处 ECM 组装的机制。