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.

抽象的 这是研究感觉神经在骨骼中的作用的程序的更新应用。我们的研究 在第一个资助期间证明感觉神经的 NGF 依赖性 TrkA 信号传导是 股骨和颅骨发育中血管生成和骨生成的主要驱动力。在这些无血管的 设置中，间充质谱系细胞域中 NGF 的急性上调随后是伤害性纤维 向内生长，随后成为增殖间充质细胞的所在地。感官封锁 通过抑制 TrkA 信号传导或破坏 NGF，神经向内生长会延缓血管形成， 破坏股骨和颅骨骨的形成。颅骨模型中的组织学数据表明，损失 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) 中的缝线和缝线过早闭合。这些观察结果提出了一个范式，其中 感觉神经在骨骼发育中发挥作用，以维持 MPC 可塑性，这一概念在 肢体再生模型，并得到最近小鼠股骨发育研究的支持。我们的初步 研究结果直接检查微流体室中感觉神经轴突与 MPC 的相互作用 表明浸润的 DRG 神经纤维诱导 MPC 增殖，但限制非接触性分化 依赖时尚。这些效应似乎是由神经源性 FSTL1 介导的，FSTL1 会诱导 MPC 增殖并损害 BMP 诱导的成骨分化。这些数据共同支持了这一前提 TrkA+ 感觉神经在骨骼发育中发挥作用，以维持干细胞的增殖、 通过提供可激活有丝分裂和抗分化的可溶性因子来达到未分化状态 信号通路。 该概念模型将在分为两个具体目标的研究中进行探索。具体目标 1 将定义 发育中的颅骨中 TrkA+ 骨骼感觉神经的时空模式，决定了它们的 对 MPC 增殖和细胞命运的影响，并进一步阐明与其相关的信号通路 神经支配受损。具体目标 2 将鉴定调节 MPC 增殖的感觉轴突衍生因子 和细胞命运决定，并最终确定 FSTL1 是影响 MPC 的神经源性因子 细胞行为。我们的结果应该为感觉神经在疾病中发挥的基本作用提供新的见解。 骨骼形态发生、稳态和修复，并提供对神经病理学的重要见解 与人类骨骼疾病相关的表现。