Role of Developmental Signaling Pathways in Maintenance of Spinal Discs

发育信号通路在椎间盘维护中的作用

• 批准号: 10609916
• 负责人: Chitra L Dahia
• 金额: $ 63万
• 依托单位: HOSPITAL FOR SPECIAL SURGERY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10609916
• 关键词: Ablation; Acceleration; Adult; Adverse effects; Affect; Age; Aging; Area; Birth; Blood; Cell Proliferation; Cell physiology; Cells; Chronic Disease; Clinical; Data; Data Set; Degenerative Disorder; Development; Developmental Process; Down-Regulation; Elderly; Embryo; Embryonic Development; Erinaceidae; Event; Extracellular Matrix; Extracellular Matrix Proteins; Financial Hardship; Foundations; Genetic; Genetic Transcription; Giant Cells; Goals; Growth; Health; Heterogeneity; Human; In Vitro; Individual; Intervertebral disc structure; Joints; Knowledge; Lateral; Lead; Learning; Ligands; Longevity; Maintenance; Maps; Modeling; Molecular; Molecular Profiling; Mus; Organ Culture Techniques; Pathology; Pathway interactions; Pattern; Phenotype; Physiological; Play; Population; Process; Production; Publishing; Quality of life; Regulation; Research; Resolution; Risk Factors; Role; SHH gene; Sampling; Serum; Signal Pathway; Signal Transduction; Spinal; Testing; Therapeutic; Time; Tissues; Vertebral column; age related; aged; aging population; burden of illness; cartilaginous; chronic back pain; cohort; effective therapy; improved; in vivo; infancy; insight; intervertebral disk degeneration; juvenile animal; knock-down; mouse model; nervous system disorder; notochord; novel; nucleus pulposus; organ growth; overexpression; pathological aging; postnatal; prevent; skeletal; small molecule; smoothened signaling pathway; spatiotemporal; stem cells; transcriptome; transcriptome sequencing; transcriptomics; vertebra body

PROJECT SUMMARY/ ABSTRACT Aging is a significant risk factor for the onset of several degenerative diseases, including spinal or intervertebral disc (IVD) degeneration and associated chronic back pain. IVD degeneration and chronic back pain are top neurological disorders and substantial financial burden, but with no therapy or cure. Each IVD has a central core of nucleus pulposus (NP), surrounded by orthogonal layers of annulus fibrosus (AF), together sandwiched between a pair of endplates that connect the IVD to the vertebral bodies. Much remains to be learned about the critical regulators of IVD growth, maturation, and maintenance, and whether their loss with age results in IVD pathologies. We will use conditional genetic mouse models, lineage tracing, heterochronic IVD organ culture, analysis of human disc samples, and unbiased approaches of high throughput transcriptomics to identify crucial developmental regulators', including sonic hedgehog (SHH), in IVD maintenance to fill in these gaps. Our central hypothesis is that Shh-expression by the NP cells is essential for growth and maturation of the IVD, and its age-related loss leads to the IVD pathologies. The expression of SHH signaling ligand by the notochord is crucial for embryogenesis. Previously, we showed that postnatal NP cells continue to express SHH, and SHH signaling regulates NP cell proliferation and ECM production by NP and AF. Though all NP cells are descendants of Shh-expressing notochord cells, our preliminary data reveals that most of them turn-off Shh expression after birth. Besides, age-related decline in Shh expression is associated with terminal differentiation of NP cells into multinucleated syncytium and subsequent loss along with the declined expression of ECM proteins that are important for IVD function. Our preliminary data also show that conditional targeting of Shh in adult mice accelerates IVD aging, along with the loss of NP cells, providing the logical premise for this new project. These data indicate that SHH signaling is crucial; however, we do not know its precise function during growth and maturation and whether it is critical for aging IVDs. Aim 1 will test the hypothesis that SHH is a critical signaling pathway and its downstream regulators play a distinct role during infancy and maturation, and its loss causes IVD pathologies. Aim 2 will test the hypothesis that Shh-expressing NP cells are the progenitor cells, and the stochastic expression of Shh regulates all NP cells' molecular heterogeneity. Aim 3 will investigate the beneficial effects of SHH signaling for delaying aging. We expect that the completion of this study will provide insights into the role of SHH as a critical regulator of growth and maturation of the IVD and identify avenues for targeting such molecules to reverse or delay the aging process and improve the quality of life of the aging population.

项目摘要/摘要 衰老是多种退化性疾病（包括脊柱或）发作的重要危险因素 椎间盘（IVD）变性和相关的慢性背痛。 IVD变性和慢性背部 疼痛是最大的神经系统疾病和巨大的经济负担，但没有治疗或治愈。每个IVD都有 原子核（NP）的中心核心，周围是环形纤维（AF）的正交层 夹在一对将IVD连接到椎体的终结物之间。还有很多 了解IVD增长，成熟和维护的关键调节因子，以及它们是否损失 年龄导致IVD病理。我们将使用有条件的遗传小鼠模型，谱系追踪，异缘人 IVD器官培养，人盘样品的分析以及高通量的公正方法 转录组学确定关键的发育调节剂，包括声音刺猬（SHH），IVD 维护以填补这些空白。我们的中心假设是，NP细胞的SHH表达对于 IVD的生长和成熟及其与年龄相关的损失导致IVD病理。表达 脊索的SHH信号配体对于胚胎发生至关重要。以前，我们显示出产后NP 细胞继续表达SHH，SHH信号传导调节NP的NP细胞增殖和ECM产生 和AF。尽管所有NP细胞都是表达SHH的脊索细胞的后代，但我们的初步数据揭示了 他们大多数出生后关闭了SHH的表情。此外，SHH表达与年龄有关的下降是 与NP细胞终末分化为多核合胞体的终末分化以及随后的损失 对于IVD功能很重要的ECM蛋白的表达下降。我们的初步数据 表明成年小鼠中SHH的条件靶向可加速IVD衰老，以及NP细胞的损失， 为这个新项目提供逻辑前提。这些数据表明SHH信号至关重要。然而， 我们不知道其在成长和成熟过程中的精确功能，以及它对IVD衰老是否至关重要。目的 1将检验以下假设：SHH是关键的信号通路，其下游调节器的作用很独特 在婴儿期和成熟期间的作用及其损失会导致IVD病理。 AIM 2将检验假设 表达SHH的NP细胞是祖细胞，SHH的随机表达调节所有NP 细胞的分子异质性。 AIM 3将研究SHH信号传导对延迟衰老的有益作用。 我们预计这项研究的完成将为SHH作为关键调节者的作用提供见解 IVD的生长和成熟并确定靶向这种分子以逆转或延迟的途径 衰老过程并改善人口老龄化的生活质量。