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

基本信息

批准号：
10469481
负责人：
Chitra L Dahia
金额：
$ 70.89万
依托单位：
HOSPITAL FOR SPECIAL SURGERY
依托单位国家：
美国
项目类别：
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/10469481
关键词：
Adult Adverse effects Affect Age Aging Area Birth 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 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 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

项目摘要

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.

项目概要/摘要衰老是多种退行性疾病发生的一个重要危险因素，包括脊柱或椎间盘（IVD）退变和相关的慢性背痛。 IVD 变性和慢性背部疼痛是最严重的神经系统疾病，造成巨大的经济负担，但没有治疗方法或治愈方法。每个 IVD 都有髓核 (NP) 的中央核心，由正交的纤维环 (AF) 层包围在一起夹在一对将 IVD 连接到椎体的终板之间。还有很多事情有待解决了解 IVD 生长、成熟和维持的关键调节因子，以及它们的损失是否与年龄会导致 IVD 病变。我们将使用条件遗传小鼠模型、谱系追踪、异时性 IVD 器官培养、人体椎间盘样本分析以及高通量的公正方法转录组学可在 IVD 中识别关键的发育调节因子，包括音猬因子 (SHH) 维护来填补这些空白。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会导致 IVD 病理。的表达式为脊索的 SHH 信号配体对于胚胎发生至关重要。之前，我们表明产后 NP 细胞持续表达SHH，SHH信号调节NP细胞增殖和NP产生ECM 和自动对焦。尽管所有 NP 细胞都是表达 Shh 的脊索细胞的后代，但我们的初步数据表明大多数人在出生后就不再表达“嘘”的表情。此外，Shh 表达与年龄相关的下降是与 NP 细胞终末分化为多核合胞体以及随后的损失相关对 IVD 功能很重要的 ECM 蛋白表达下降。我们的初步数据还表明在成年小鼠中条件性靶向 Shh 会加速 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 信号传导至关重要；然而，我们不知道它在生长和成熟过程中的确切功能，也不知道它是否对 IVD 老化至关重要。目的 1 将检验 SHH 是一条关键信号通路及其下游调节因子发挥独特作用的假设在婴儿期和成熟期发挥作用，其丧失会导致 IVD 病理。目标 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。目标 3 将研究 SHH 信号传导对延缓衰老的有益作用。我们期望这项研究的完成将深入了解 SHH 作为关键监管者的作用。 IVD 的生长和成熟，并确定靶向此类分子以逆转或延迟 IVD 的途径老龄化进程，提高老龄人口的生活质量。