Mechanisms of mechanical transduction in the guidance of neuronal axons

神经元轴突引导的机械转导机制

• 批准号: 8165313
• 负责人: Simon Wayne Moore
• 金额: $ 10.71万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8165313
• 关键词: Actins; Address; Adult; Antibodies; Aplysia; Axon; Behavior; Binding; Biochemical; Biological Assay; Cell Surface Receptors; Cell membrane; Cells; Chemicals; Collagen Type I; Coupling; Cues; Cytoskeleton; Development; Devices; Dimensions; Disease; Dyes; ERM protein; Environment; Event; Extracellular Domain; Extracellular Matrix; Failure; Fibronectins; Focal Adhesion Kinase 1; Growth Cones; Height; Image; Imaging Techniques; Injury; Investigation; Learning; Link; Magnetism; Maps; Measures; Mechanics; Mediating; Mentors; Metalloproteases; Microscopy; Modeling; Molds; Mus; Mutate; Myosin ATPase; N-terminal; Nervous System Trauma; Nervous system structure; Neurons; Optics; Organism; Pattern; Phase; Physiological; Polylysine; Population; Positioning Attribute; Process; Proteins; Publishing; RGD (sequence); Rattus; Regulation; Research; Resolution; Role; Side; Signal Transduction; Site; Spinal; Spinal Ganglia; Spinal cord injury; Stretching; Stroke; Structure; Techniques; Testing; Traction; Traumatic Brain Injury; Work; Xenopus; axon guidance; axon regeneration; base; disability; extracellular; human NTN1 protein; improved; inhibitor/antagonist; insight; laminin-1; laser tweezer; mutant; nanofabrication; netrin-1; neuronal cell body; neuronal guidance; optical traps; protein purification; protein structure; radixin protein; receptor; regenerative; response; sugar; theories

DESCRIPTION (provided by applicant): The adult nervous system can be thought of as a network of neuron cell bodies connected to each other by thin processes called axons. During development, these axonal extensions are guided to their target by patterned chemical cues in their environment. Failure to reestablish these axonal connections is a major cause of the persistent disabilities of a number of disease conditions, including: spinal cord injury, traumatic brain injury and stroke. The leading tip of an axon, known as a growth cone, uses cell surface receptors to recognize these chemical cues. The growth cone is also a mechanical structure that pulls on its surroundings to move forward. In theory, cues could have an indirect role in influencing the coupling of the growth cone's locomotive machinery to its surroundings. However, I have recently shown that at least one of these cues - netrin-1 - is directly used for traction. In other words, the ability of netrin-1 to attract the growth cone reflects its ability support the growth cone's mechanical pulling. My current work examines a protein called focal adhesion kinase (FAK) within the growth cone that links this cue to the cytoskeleton. I have discovered that the mechanical tension felt on this protein activates its catalytic activity resulting in biochemical cascades that reinforces the link to the cue. In this application, I propose to use optical laser tweezers, magnetic tweezers, super resolution imaging techniques and nano-fabricated pillar arrays to address four other fundamentally important lines of investigation that have emerged from my previous work: (1) Determine how FAK is attached to cytoskeleton and whether it is physical stretched in cells. (2) Test the effect of chemical composition and rigidity of the environment, as well as, changes between different neuronal populations on the pulling strength of the growth cone. (3) Examine whether other attractive axon guidance cues used for traction. (4) Explore whether mechanical tension felt on the cue and its receptor alters their function by inducing conformational changes. Michael Sheetz' lab offers a unique environment to learn and utilize the techniques necessary to address these questions. Two additional co-mentors will provide complimentary expertise: John Hunt is world leader on protein purification and structure, while James Hone is an expert on generating cutting-edge nanofabricated devices. Insights gained from this project will further our basic understanding of axon guidance and therefore contribute to the development of better regenerative strategies following injury of the nervous system. PUBLIC HEALTH RELEVANCE: Insights gained from this project will further our basic understanding of axon guidance. Failure to reestablish axonal connections is a major cause of the disabilities seen following a number of disease conditions, including: spinal cord injury, traumatic brain injury and stroke. This project therefore contributes to the development of better regenerative strategies following injury to the nervous system.

描述（由申请人提供）：成人神经系统可以被认为是神经元细胞体的网络，通过称为轴突的细突彼此连接。在发育过程中，这些轴突延伸通过其环境中的图案化化学线索引导至其目标。无法重建这些轴突连接是导致许多疾病持续残疾的主要原因，包括：脊髓损伤、创伤性脑损伤和中风。 轴突的尖端（称为生长锥）使用细胞表面受体来识别这些化学信号。生长锥也是一种机械结构，拉动周围环境向前移动。从理论上讲，线索可能会间接影响生长锥的机车机械与其周围环境的耦合。然而，我最近证明，这些线索中至少有一个 - netrin-1 - 直接用于牵引。换句话说，netrin-1吸引生长锥的能力反映了其支持生长锥机械牵引的能力。我目前的工作是检查生长锥内一种称为粘着斑激酶 (FAK) 的蛋白质，该蛋白质将这一线索与细胞骨架联系起来。我发现这种蛋白质感受到的机械张力会激活其催化活性，从而产生生化级联，从而加强与提示的联系。 在此应用中，我建议使用光学激光镊子、磁性镊子、超分辨率成像技术和纳米制造柱阵列来解决我之前的工作中出现的其他四个基本重要的研究方向：（1）确定 FAK 是如何附着的细胞骨架以及它是否在细胞中物理拉伸。 (2)测试环境的化学成分和硬度以及不同神经元群体之间的变化对生长锥拉力的影响。 (3) 检查是否有其他有吸引力的轴突引导线索用于牵引。 (4) 探索提示及其受体感受到的机械张力是否通过诱导构象变化来改变它们的功能。 Michael Sheetz 的实验室提供了一个独特的环境来学习和利用解决这些问题所需的技术。另外两位共同导师将提供免费的专业知识：约翰·亨特 (John Hunt) 是蛋白质纯化和结构领域的世界领导者，而詹姆斯·霍恩 (James Hone) 是生成尖端纳米制造设备的专家。从该项目中获得的见解将进一步加深我们对轴突引导的基本理解，从而有助于在神经系统损伤后制定更好的再生策略。 公共卫生相关性：从该项目中获得的见解将进一步加深我们对轴突引导的基本理解。无法重建轴突连接是许多疾病导致残疾的主要原因，这些疾病包括：脊髓损伤、创伤性脑损伤和中风。因此，该项目有助于开发神经系统损伤后更好的再生策略。