Molecular mechanisms regulating motility and migration of muscle satellite cells

调节肌肉卫星细胞运动和迁移的分子机制

• 批准号: 7572440
• 负责人: Dawn D Cornelison
• 金额: $ 16.17万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7572440
• 关键词: 3-Dimensional; Acute; Address; Adhesions; Adult; Affect; Antibodies; Area; Basic Science; Behavior; Binding; Biological; Biological Assay; Blocking Antibodies; Cell Adhesion; Cell Communication; Cell Culture Techniques; Cell Surface Proteins; Cell Therapy; Cell physiology; Cells; Clinical; Collaborations; Collagen; Cues; Cytoskeleton; DNA Sequence Rearrangement; Data; Defect; Development; Disease; Embryo; Endothelial Cells; Engraftment; Environment; Event; Exhibits; Explosion; Extracellular Matrix; Fiber; Fibroblast Growth Factor 2; Fibroblasts; Foundations; Goals; Grant; Growth Factor; Hepatocyte Growth Factor; Heterogeneity; Home environment; In Vitro; Individual; Infection; Injection of therapeutic agent; Injury; Integrins; Intrinsic factor; Ligands; Lipids; Measures; Mediating; Methods; Modeling; Molecular; Monomeric GTP-Binding Proteins; Mus; Muscle; Muscle Fibers; Muscle satellite cell; Muscular Dystrophies; Mutagens; Mutant Strains Mice; Mutation; Myoblasts; Natural regeneration; Neurons; Peptides; Pharmacologic Substance; Population; Procedures; Proliferating; Protein Isoforms; Proteins; Protocols documentation; Receptor Signaling; Regulation; Research Personnel; Role; Signal Pathway; Signal Transduction; Site; Skeletal Muscle; Stem cells; Stimulus; Surveys; System; Techniques; Time; Tissues; Vertebrates; Video Microscopy; Viral; Viral Vector; Work; adult stem cell; base; cell motility; chemokine; extracellular; gene therapy; in vivo; inhibitor/antagonist; insight; interest; migration; mimetics; muscle regeneration; mutant; myogenesis; novel; population migration; public health relevance; receptor; repaired; response; rho; satellite cell; syndecan-4; therapeutic effectiveness; tool; vector

DESCRIPTION (provided by applicant): Repair and replacement of damaged skeletal muscle in vertebrates requires the activity of a population of resident adult stem cells (satellite cells.) Following acute injury, these relatively rare and highly dispersed cells are required to respond by quickly becoming `activated', multiplying to produce a large pool of replacement myoblasts, relocating to the site of the injury, and differentiating to form new muscle fibers. The molecular and cellular processes required for adult myogenesis (regeneration) overlap with, but are largely distinct from, those active in the embryo when muscle is first formed. At the level of the cell's interactions with the extracellular environment, the requirements for satellite cell motility and migration within the tissue are a critical aspect of muscle regeneration that has not been well explored. In collaboration with Dr. George Davis, we have combined primary satellite cell culture on their host myofibers in a programmable 3D collagen matrix with timelapse videomicroscopy to develop a novel system for qualitatively and quantitatively examining satellite cell migration on their native substrate. Conditions can be altered by addition of exogenous stimuli such as potential mutagens, blocking of soluble or cell-surface proteins with antibodies or peptide mimetics, addition of pharmacological inhibitors of specific signaling pathways or cytoskeletal remodelers, specific infection of satellite cells with viral expression constructs, or use of fibers and satellite cells derived from targeted mutations; all of these can also be assayed both individually and in combination. We have used this system to assess the roles of soluble factors such as growth factors, chemokines and signaling lipids; extracellular matrix and adhesion factors; transmembrane signaling receptors and integrins; and intracellular modulators of the cytoskeleton. Our goal for this short-term exploratory grant is to extend and refine these results to build a working model of satellite cell migration in the context of these defined classes of signaling factors and effectors. Once we have identified critical interactions and points of control, we will continue on to ask how such activities are integrated within individual satellite cells to effect a coherent migration of the population of proliferating myoblasts towards an area of injury. Our broad, long-term goal is to understand how satellite cells detect, integrate, and respond appropriately in time and space to the transient and dynamic signaling environment that would constitute a muscle injury in vivo, with the biological robustness that is taken for granted in healthy muscle tissue and compromised in dystrophic muscle. PUBLIC HEALTH RELEVANCE: In addition to addressing an underexplored facet of basic research into the mechanisms of adult myogenesis, this project has high potential to contribute to the development of satellite cell- based therapies for diseases such as the muscular dystrophies. A critical area of concern in current adult myoblast and muscle-derived stem cell engraftment procedures is the unmet requirement for injected cells to, at least, disperse broadly from the injection site or, at best, actively home to either investigator-defined sites or sites of maximum damage. By providing insight into the motogenic stimuli, preferred migration substrate, and specific guidance cues used by satellite cells migrating in a system (single fiber culture) that could be expected to recapitulate many of the influences found in vivo, this work will ideally suggest potential avenues to modify current myoblast engraftment protocols to enhance their therapeutic effectiveness.

描述（由申请人提供）：脊椎动物受损骨骼肌的修复和替换需要一群常驻成体干细胞（卫星细胞）的活性。急性损伤后，这些相对罕见且高度分散的细胞需要通过快速“激活”、繁殖以产生大量替代成肌细胞、重新定位到损伤部位并分化形成新的肌纤维来做出反应。成体肌发生（再生）所需的分子和细胞过程与肌肉首次形成时胚胎中活跃的分子和细胞过程重叠，但在很大程度上不同。在细胞与细胞外环境相互作用的水平上，组织内卫星细胞运动和迁移的要求是肌肉再生的一个关键方面，但尚未得到充分探索。我们与 George Davis 博士合作，将可编程 3D 胶原基质中宿主肌纤维上的原代卫星细胞培养物与延时视频显微镜相结合，开发了一种新颖的系统，用于定性和定量检查卫星细胞在其天然基质上的迁移。可以通过添加外源刺激来改变条件，例如潜在的诱变剂，用抗体或肽模拟物封闭可溶性或细胞表面蛋白，添加特定信号传导途径或细胞骨架重塑剂的药理学抑制剂，用病毒表达构建体特异性感染卫星细胞，或使用源自靶向突变的纤维和卫星细胞；所有这些都可以单独或组合进行测定。我们使用该系统来评估可溶性因子的作用，例如生长因子、趋化因子和信号脂质；细胞外基质和粘附因子；跨膜信号受体和整合素；和细胞骨架的细胞内调节剂。我们这项短期探索性资助的目标是扩展和完善这些结果，以在这些定义的信号因子和效应器类别的背景下建立卫星细胞迁移的工作模型。一旦我们确定了关键的相互作用和控制点，我们将继续询问如何将这些活动整合到单个卫星细胞内，以实现增殖的成肌细胞群向损伤区域的一致迁移。我们广泛、长期的目标是了解卫星细胞如何在时间和空间上检测、整合和适当响应瞬态和动态信号环境，这些环境将构成体内肌肉损伤，而生物稳健性在健康肌肉组织中是理所当然的，而在营养不良肌肉中却受到损害。 公共健康相关性：除了解决成人肌生成机制基础研究中尚未充分探索的方面之外，该项目还具有很大的潜力，有助于开发基于卫星细胞的疾病疗法，例如肌营养不良症。当前成体成肌细胞和肌肉源性干细胞植入程序中一个令人关注的关键领域是注射细胞的要求未得到满足，即至少从注射部位广泛分散，或者最多主动归巢到研究者定义的部位或最大损伤部位。通过深入了解运动刺激、首选迁移底物以及卫星细胞在系统（单纤维培养）中迁移所使用的特定引导线索，有望重现体内发现的许多影响，这项工作将理想地提出修改当前成肌细胞移植方案以增强其治疗效果的潜在途径。