Neuroskeletal crosstalk in load-induced bone formation

负荷诱导骨形成中的神经骨骼串扰

• 批准号: 10464348
• 负责人: Alec T Beeve
• 金额: $ 4.93万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10464348
• 关键词: ACTL6B gene; Affect; Affinity; Anabolism; Axon; Biology; Biomechanics; Bone Diseases; Bone Surface; Cell physiology; Complex; Cues; Data; Denervation; Development; Diabetes Mellitus; Disease; Efferent Neurons; Environment; Esthesia; Exercise; Exhibits; Fellowship; Fluorescent Dyes; Foundations; Functional disorder; Future; Gatekeeping; Gene Expression; Genes; Goals; Health; Hindlimb; Histologic; Histology; Homeostasis; Human; Image; Image Analysis; Imaging Techniques; Immunohistochemistry; Impairment; In Situ Hybridization; Laboratory Research; Limb structure; Literature; Maps; Mature Bone; Mentors; Mentorship; Metabolism; Methods; Minerals; Modeling; Modification; Multiple Sclerosis; Mus; NGFR Protein; Nerve; Nerve Fibers; Nerve Growth Factors; Nervous system structure; Neurons; Neuropathy; Neurotrophic Tyrosine Kinase Receptor Type 1; Osteoblasts; Osteoclasts; Osteocytes; Osteogenesis; Osteoporosis; Outcome; Patients; Pattern; Periodicity; Periosteum; Peripheral Nerves; Physiology; Play; Population; Pre-Clinical Model; Protocols documentation; Regimen; Reporter; Research; Role; Running; Sensory; Signal Transduction; Skeleton; Spinal cord injury; Surface; Technical Expertise; Techniques; Testing; Therapeutic Effect; Training; Treatment Efficacy; Universities; Up-Regulation; WNT1 gene; Washington; Weight-Bearing state; Work; base; bone; bone cell; bone health; bone loss; career; chemotherapy; density; design; fluorexon; fracture risk; fragility fracture; improved; in vivo; long bone; mechanical load; mechanical stimulus; medical schools; mineralization; nerve supply; neuron loss; neuroregulation; neurotransmission; neurotransmitter release; novel; response; skeletal; skeletal disorder; tibia; tool

PROJECT SUMMARY/ABSTRACT Peripheral nerve dysfunction is associated with skeletal fragility in humans and in preclinical models. While proprioceptive deficits play a significant role in increased fracture risk, loss of local innervation may deplete bone of neuronal factors critical for skeletal homeostasis. This presents new challenges for maintaining bone health in patients with neuropathy and those undergoing nerve-modifying treatments. Specifically, it may affect the therapeutic efficacy of weight-bearing exercise. Mechanically loading bone through exercise is a well-established requirement for bone health. Compression of long bones results in skeletal remodeling to increase strength. In addition, bone cells secrete neurotrophic cues after loading that may facilitate nerve sprouting towards the skeleton, modifying endogenous skeletal innervation patterns. Considering this emerging role of nerves in skeletal metabolism, local neuroskeletal signaling may be required to facilitate load-induced bone formation. The central goal of this proposal is to investigate the plasticity and necessity of neuroskeletal crosstalk in the anabolic response of bone to compressive loading. To accomplish this, the proposed research is divided into two aims. In Aim 1, novel neuroskeletal niches involved in load-induced bone formation will be defined. To investigate how native neuroskeletal niches are modified during skeletal adaptation, a 5-day regimen of in vivo axial compression will be conducted on mice to induce lamellar bone formation, followed by histology and imaging of the tibia. Nerves in bone will be mapped using a novel pan-neuronal Baf53b-Ai9 reporter mouse and immunostaining for nerve subtypes. In addition, local Ngf and Wnt1 gene expression will be mapped in relation to defined neuroskeletal niches using in situ hybridization. To study the spatial localization and relative quantities of axons, mineralizing surface, and gene expression, a novel image analysis workflow (RadialQuant) will be used. In Aim 2, the necessity of these neuroskeletal niches for load-induced bone formation will be evaluated. To test this, a model of tibial denervation will be developed by evaluating neuronal loss after one-week of femoral and/or sciatic neurectomy using the imaging techniques employed in Aim 1. To test the necessity of innervation in skeletal adaptation, the hindlimb will be denervated accordingly prior to cyclic axial compression as in Aim 1. Techniques from Aim 1 will be used isolate the effect of loading and denervation on axon density, mineral apposition, and gene expression. The long-term career goal of the applicant is to run an independent research laboratory. In addition to the research plan, the training plan is designed to achieve this goal through development of new technical skills, mentorship, and critical synthesis of literature. The two-year fellowship will be conducted at the Washington University School of Medicine under the mentorship of Dr. Erica Scheller and Dr. Matthew Silva, with expertise in neuroskeletal biology and bone biomechanics, respectively.

项目概要/摘要 周围神经功能障碍与人类和临床前模型中的骨骼脆弱性有关。 虽然本体感觉缺陷在增加骨折风险中起着重要作用，但局部神经支配的丧失可能会导致骨折风险增加。 消耗对骨骼稳态至关重要的神经元因子。这对维护工作提出了新的挑战 神经病患者和接受神经修饰治疗的患者的骨骼健康。具体来说，可以 影响负重运动的治疗效果。通过运动对骨骼进行机械负载是一种 对骨骼健康的既定要求。长骨的压缩导致骨骼重塑 增加力量。此外，骨细胞在负载后会分泌神经营养信号，这可能有助于神经 向骨骼发芽，改变内源性骨骼神经支配模式。考虑到这一新兴 由于神经在骨骼代谢中的作用，可能需要局部神经骨骼信号来促进负荷诱导 骨形成。该提案的中心目标是研究神经骨骼的可塑性和必要性 骨对压缩载荷的合成代谢反应中的串扰。为了实现这一目标，拟议的研究 分为两个目标。在目标 1 中，参与负荷诱导骨形成的新型神经骨骼生态位将是 定义的。为了研究在骨骼适应过程中原生神经骨骼生态位如何被修改，为期 5 天的研究 将对小鼠进行体内轴向压缩方案以诱导板层骨形成，然后 胫骨的组织学和成像。将使用新型泛神经元 Baf53b-Ai9 绘制骨骼神经图 报告小鼠和神经亚型的免疫染色。此外，局部 Ngf 和 Wnt1 基因表达将 使用原位杂交与定义的神经骨骼生态位进行映射。来研究空间 轴突、矿化表面和基因表达的定位和相对数量，一种新颖的图像分析 将使用工作流程 (RadialQuant)。在目标 2 中，这些神经骨骼生态位对于负载诱导的必要性 将评估骨形成。为了测试这一点，将通过评估来开发胫骨去神经模型 使用成像技术进行股骨和/或坐骨神经切除术一周后神经元丢失 目标1.为了测试骨骼适应中神经支配的必要性，后肢将相应地去神经支配 在目标 1 中的循环轴向压缩之前。将使用目标 1 中的技术来隔离载荷的影响 去神经支配对轴突密度、矿物质并置和基因表达的影响。的长期职业目标 申请人将经营一个独立的研究实验室。除了研究计划外，还有培训计划 旨在通过开发新技术技能、指导和关键综合来实现这一目标 文学。这项为期两年的研究金将在华盛顿大学医学院进行 Erica Scheller 博士和 Matthew Silva 博士的指导，他们拥有神经骨骼生物学和骨骼方面的专业知识 分别是生物力学。