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 这是调查感觉神经在骨骼中的作用的程序的续签应用。我们的研究 在第一个资金期间 发育中的股骨和头骨中血管生成和成骨的主要驱动力。在这些血管中 设置，在间充质谱系细胞结构域中NGF的急性上调之后是伤害感受器 indrowth，后来又回到了增殖间充质细胞的位置。封锁感官 神经向内生长是通过抑制TRKA信号传导或NGF的破坏，会阻碍血管形成和 破坏股骨和颅骨形成。瓦尔瓦里亚模型中的组织学数据表明损失 感觉神经纤维与增殖的间充质祖细胞数量减少有关 （MPC）在缝合线和过早的缝合线闭合中。这些观察结果表明了一个范式 感觉神经在发展骨骼以维持MPC可塑性方面发挥作用，这是一个很好地确定的概念 肢体再生模型，并得到了近期发展小鼠股骨的研究的支持。我们的初步 发现直接检查感觉神经轴突与MPC在微流体腔中的相互作用 建议浸润DRG神经纤维会诱导MPC增殖，但限制了非接触式的分化 依赖的时尚。这些作用似乎是由诱导MPC的神经衍生的FSTL1介导的 增殖并损害BMP诱导的成骨分化。在一起，这些数据支持前提 TRKA+感觉神经在发育骨骼中起作用以维持增生性干细胞， 通过传递激活有丝分裂和抗差异的可溶因子，未分化的状态 信号通路。 该概念模型将在分为两个特定目标的研究中探索。特定目标1将定义 发育中的颅骨中TRKA+骨骼感觉神经的时空模式 对MPC增殖和细胞命运的影响，并进一步阐明与 神经受损。特定的目标2将确定调节MPC增殖的感觉轴突衍生的因素 和细胞命运的决策，并确定将FSTL1识别为影响MPC的神经衍生因素 细胞行为。我们的结果应为感官神经在 骨骼形态发生，稳态和修复，并为神经病理学提供了重要的见解 与人类骨骼疾病相关的表现。