Neuronal Regulation of Skeletal Development and Repair

骨骼发育和修复的神经元调节

• 批准号: 10704223
• 负责人: Thomas L Clemens
• 金额: $ 46.58万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-20 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10704223
• 关键词: Acute; Afferent Neurons; Area; Axon; Blood Vessels; Bone Diseases; Calvaria; Cell Differentiation process; Cell Lineage; Cell Proliferation; Cells; Cephalic; Coculture Techniques; Collaborations; Data; Dermal; Femur; Fiber; Follistatin; Funding; Genetic Transcription; Genomics; Growth; Histologic; Home; Homeostasis; Human; Impairment; In Vitro; Infiltration; Joint structure of suture of skull; Knock-in Mouse; Legal patent; Location; Maps; Mediating; Mesenchymal; Mesenchymal Stem Cells; Methods; Microfluidics; Modeling; Molecular; Monitor; Morphogenesis; Mus; Natural regeneration; Nerve; Nerve Fibers; Nerve Growth Factors; Neurons; Nociception; Osteogenesis; Pattern; Peripheral; Phenocopy; Phenotype; Phosphotransferases; Play; Proliferating; Recombinants; Regulation; Reporter; Reporting; Role; Scaphycephaly; Sensory; Signal Pathway; Signal Transduction; Skeletal Development; Surgical sutures; Techniques; Time; Transgenic Organisms; Tropomyosin; Undifferentiated; Up-Regulation; Vascularization; adenovirus mediated delivery; afferent nerve; angiogenesis; bone; bone repair; cell behavior; cranium; gene network; genetic signature; inhibitor; insight; limb regeneration; mechanical load; nerve supply; neural; neuropathology; neurotropic; osteogenic; osteoprogenitor cell; premature; preservation; programs; receptor; repaired; response; skeletal; skeletal stem cell; spatiotemporal; stem cell expansion; stem cell proliferation; stem cells; time interval; tool; transcriptomics

ABSTRACT This is a renewal application of a program investigating the role of sensory nerves in bone. Our studies during the first funding period demonstrate that NGF-dependent TrkA signaling by sensory nerves is the primary driver of angiogenesis and osteogenesis in the developing femur and skull. In these avascular settings, acute up-regulation of NGF in mesenchymal lineage cell domains is followed by nociceptive fiber ingrowth, which subsequently home to locations of proliferating mesenchymal cells. Blockade of sensory nerve ingrowth, either by inhibition of TrkA signaling or disruption of NGF, retards vascularization and disrupts femoral and calvarial bone formation. Histological data in the calvaria model revealed that loss of sensory nerve fibers is associated with reduced numbers of proliferating mesenchymal progenitor cells (MPCs) in the sutures and premature suture closure. These observations suggest a paradigm in which sensory nerves function in developing bone to maintain MPC plasticity, a concept well established in models of limb regeneration and supported by recent studies in developing mouse femur. Our preliminary findings directly examining the interaction of sensory nerve axons with MPCs in microfluidic chambers suggest that infiltrating DRG nerve fibers induce MPC proliferation, but limit differentiation in a non-contact dependent fashion. These effects appear to be mediated by neural derived FSTL1, which induces MPC proliferation and impairs BMP-induced osteogenic differentiation. Together, this data support the premise that TrkA+ sensory nerves function in developing bone to maintain stem cells in a proliferative, undifferentiated state by delivering soluble factors that activate mitogenic and anti-differentiation signaling pathways. This conceptual model will be explored in studies divided into two Specific Aims. Specific Aim 1 will define the spatiotemporal patterning of TrkA+ skeletal sensory nerves in the developing cranium, determine their influence on MPC proliferation and cellular fate, and further elucidate signaling pathways associated with impaired innervation. Specific Aim 2 will identify sensory axon-derived factors that regulate MPC proliferation and cell fate decisions, and definitively identifying FSTL1 as a neural-derived factor which impacts MPC cellular behavior. Our results should provide new insights into the fundamental roles sensory nerves play in skeletal morphogenesis, homeostasis and repair, and provide critical insight into the neuropathological manifestations associated with bone disorders in humans.

摘要 这是一个更新的应用程序调查的作用，感觉神经在骨。我们的研究 在第一个资助期内，研究人员证明了感觉神经的NGF依赖性TrkA信号传导是 在发育中的股骨和颅骨中血管生成和骨生成的主要驱动力。在这些无血管的 在这种情况下，间充质谱系细胞结构域中的NGF的急性上调之后是伤害性纤维， 向内生长，其随后回到增殖间充质细胞的位置。感觉阻滞 通过抑制TrkA信号传导或破坏NGF，神经向内生长延缓血管形成， 破坏了股骨和颅骨的形成颅骨模型的组织学数据显示， 感觉神经纤维的减少与增殖间充质祖细胞数量的减少有关 （MPC）和缝线过早闭合。这些观察表明了一种范式， 感觉神经在骨骼发育中起作用，以维持MPC的可塑性，这一概念在 肢体再生的模型，并支持最近的研究在发展小鼠股骨。我们的初步 直接检查感觉神经轴突与微流控室中MPC相互作用的发现 提示浸润DRG神经纤维诱导MPC增殖，但限制了非接触性的分化。 依赖的方式。这些作用似乎是由神经源性FSTL 1介导的，其诱导MPC 增殖并损害BMP诱导的成骨分化。这些数据共同支持了 TrkA+感觉神经在骨发育中起作用， 通过递送激活促有丝分裂和抗分化的可溶性因子 信号通路 这个概念模型将在分为两个具体目标的研究中进行探讨。具体目标1将定义 TrkA+骨骼感觉神经在发育中的颅骨中的时空模式，确定其 对MPC增殖和细胞命运的影响，并进一步阐明与 神经支配受损特异性目标2将确定调控MPC增殖的感觉轴突衍生因子 和细胞命运决定，并明确确定FSTL 1作为影响MPC的神经源性因子 细胞行为我们的研究结果应该为感觉神经在神经系统中的基本作用提供新的见解。 骨骼形态发生，稳态和修复，并提供关键的洞察神经病理 与人类骨骼疾病相关的临床表现。