Mechanisms of axonal pathfinding in three dimensional matrices

三维矩阵中轴突寻路的机制

• 批准号: 8729691
• 负责人: Jeffrey S. Urbach
• 金额: $ 6.34万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-28 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8729691
• 关键词: Area; Axon; Biochemical; Cellular biology; Collagen; Collagen Fibril; Complex; Computer software; Controlled Environment; Cues; Development; Eating; Engineering; Environment; Extracellular Matrix; Filopodia; Focal Adhesions; Gel; Generations; Goals; Growth; Growth Cones; Image; Image Analysis; Immigration; Implant; In Vitro; Injury; Intervention; Knowledge; Laboratories; Laminin; Measures; Mechanics; Microscope; Microtubule Polymerization; Microtubules; Modeling; Molecular; Morphology; Myosin ATPase; Natural regeneration; Nerve; Nerve Regeneration; Neuraxis; Neurons; Pattern; Physics; Process; Rattus; Research; Research Personnel; Role; Science; Speed; Spinal Injuries; Spinal cord injury; Structure; System; Techniques; Testing; Translating; Width; axon growth; axon guidance; axonal guidance; axonal pathfinding; blebbistatin; cell motility; cell type; design; effective therapy; extracellular; implant material; in vitro Assay; in vivo; injured; nervous system development; novel; physical property; preference; public health relevance; response; spinal nerve posterior root; tool

DESCRIPTION (provided by applicant): A detailed understanding of the processes that control axon growth and guidance is essential for understanding the development of the nervous system and for engineering successful regrowth of severed neurons following spinal cord injury. While many of the molecules responsible for enhancing or inhibiting growth and for attractive and repulsive guidance have been identified, the majority of our knowledge of the mechanisms of axon motility comes from studies on flat, featureless, stiff substrates. There is accumulating evidence, however, that cell motility is sensitive to the structural and mechanical environ- ment. Conversely, there has been significant progress in creating structural features that control axon growth in complex environments in vitro and in vivo, but in most cases the mechanisms responsible for the modulation of motility are not known. The goal of the proposed research is to investigate axonal guidance in rigorously controlled mechanical and structural environments using imaging and analysis tools that will reveal subcellular morphology and dynamics with unprecedented detail. These studies will elucidate the roles of filopodia, focal adhesions, mechanical forces and guidance factors in controlled environments, and provides crucial information for the development of manipulations of the extracellular environment in vivo that impact axon motility in predictable ways, and for the engineering of implant materials to promote nerve regeneration after injury. Our specific aims are to: (1) Determine the mechanisms by which filopodia-collagen fibril interactions promote axon motility and guidance in 3D (2) Assess the effects of matrix composition on growth cone morphology, axon outgrowth, and axon guidance in 3D collagen-I matri- ces, and (3) Test the hypothesis that axons confined to narrow lanes, which mimic fibrillar confinement, are less responsive to non-directed guidance cues. This research will utilize a specialized high-speed, high sensitivity spinning disk confocal microscope system developed in the laboratory of the PI, as well as customized image analysis software. The research is an interdisciplinary collaborative effort involving re- searchers with expertise in cell biology, physics, materials science, and engineering. This effort will produce an entirely new perspective on axon motility and should significantly advance our ability to understand and control axon growth in complex environments.

描述（由申请人提供）：详细了解控制轴突生长和引导的过程对于理解神经系统的发育和脊髓损伤后切断神经元的工程成功再生至关重要。 虽然许多负责增强或抑制生长和吸引和排斥指导的分子已经被确定，但我们对轴突运动机制的大部分知识来自对平坦，无特征，坚硬基质的研究。 然而，越来越多的证据表明，细胞运动对结构和机械环境敏感。 相反，已经有显着的进展，创造控制轴突生长在复杂的环境中，在体外和体内的结构特征，但在大多数情况下，负责运动的调制机制是未知的。 拟议研究的目标是使用成像和分析工具在严格控制的机械和结构环境中研究轴突引导，这些工具将以前所未有的细节揭示亚细胞形态和动力学。 这些研究将阐明丝状伪足，局灶性粘连，机械力和指导因素在受控环境中的作用，并提供了重要的信息，在体内的细胞外环境的操作，影响轴突运动的可预测的方式，并为工程植入材料，以促进损伤后的神经再生的发展。 我们的具体目标是：（1）确定丝状伪足-胶原纤维相互作用促进3D中轴突运动和引导的机制（2）评估基质成分对3D胶原-I基质中生长锥形态、轴突生长和轴突引导的影响，以及（3）测试限制在狭窄通道（模拟纤维限制）的轴突对非定向引导线索的反应较低的假设。 本研究将利用PI实验室开发的专用高速，高灵敏度旋转圆盘共聚焦显微镜系统以及定制的图像分析软件。 这项研究是一项跨学科的合作努力，涉及细胞生物学，物理学，材料科学和工程学方面的专业知识。 这一努力将产生一个全新的视角轴突运动，并应显着提高我们的能力，了解和控制轴突生长在复杂的环境。