Mechanisms for Regenerative Healing in Intervertebral Discs

椎间盘再生愈合机制

• 批准号: 10344363
• 负责人: James C. Iatridis
• 金额: $ 56.65万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-15 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10344363
• 关键词: Adult; Affect; Age; Aging; Anatomy; Atomic Force Microscopy; Back Pain; Biomechanics; Caliber; Cell Maturation; Cell Proliferation; Cell Therapy; Cells; Chronic; Clinical Trials; Collagen; Data; Defect; Deposition; Engineering; Environment; Extracellular Matrix; Fibrosis; Functional disorder; Genetic; Gold; Growth; Height; Human; Inflammation; Injections; Injury; Integrins; Intervertebral disc structure; Ligands; Mediating; Microscopy; Mitosis; Mitotic; Modeling; Modulus; Mus; Natural regeneration; Neonatal; Nerve; Outcome; Pain; Phenotype; Play; Population; Population Heterogeneity; Process; Property; Protein-Lysine 6-Oxidase; Puncture procedure; Recurrence; Regenerative Medicine; Regenerative capacity; Role; Thinking; Time; Tissue Engineering; Tissues; beta Aminopropionitrile; cell regeneration; crosslink; density; design; disability; disability impact; discogenic pain; effective therapy; ethylene glycol; healing; improved; inhibitor; innovation; intervertebral disk degeneration; mouse model; nanoindentation; neonate; neurovascular; novel; nucleus pulposus; postnatal; progenitor; recruit; regeneration potential; regenerative; regenerative repair; repair strategy; restoration; scleraxis; skeletal; standard care; stem cells; tool; transcriptome sequencing; treatment strategy

Summary Intervertebral disc (IVD) degeneration contributes to ~40% of back pain cases. Structural IVD defects distinguish degeneration from aging and play a role pain and disability. There is a critical unmet need for improved annulus fibrosus (AF) repair strategies since discectomy, the gold standard treatment for removing herniated nucleus pulposus (NP) tissue from AF defects, leaves AF defects unrepaired and complications include reherniation and recurrent degeneration-related pain. While clinical trials of IVD cell therapy show promise to reduce discogenic pain and disability they do not involve optimized delivery strategies, and are not informed by natural IVD healing processes since remarkably little is known about the diversity of AF cell populations and their roles in healing. We believe an IVD regenerative healing model is required to identify successful AF healing strategies and to identify cellular and micromechanical factors critical in successful healing to serve as a roadmap for regenerative medicine treatments. We've developed a successful regenerative AF healing model in mice and show neonatal IVDs with severe AF puncture heal with complete restoration of IVD height and biomechanical properties while adults heal fibrotic deposition and loss of IVD height and biomechanical function. The premise of this project is that neonates regeneratively heal while skeletally mature mice do not due to increased extracellular matrix (ECM) stiffness and altered ligand presentation resulting in terminal differentiation of AF progenitors. Aim 1 determines effects of growth, maturation, and matrix stiffness on IVD healing and determines when the regenerative window closes. We apply mouse models to determines the postnatal age that the AF regenerative healing window closes, if complete AF structural regeneration is possible, and if altering ECM stiffness can extend the regenerative healing window and prolong the age when AF cells are in mitosis. Aim 2 identifies distinct AF progenitor populations, their loss with maturation, and roles of these progenitors in healing. We use single cell and spatial sequencing in mouse IVDs to identify distinct AF cell populations and their localization in mice of regenerative healing, post-regenerative healing, and regenerative restoration groups. Aim 3 engineers a soft-synthetic substrate that promotes immature AF cell phenotypes. We identify design criteria in mouse and human ECM and cells and control substrate stiffness, ligand type, and density using functionalized poly(ethylene glycol) substrates. Outcomes of this project include determining when the IVD regenerative repair window closes and if full regeneration is possible; identifying disperse AF progenitor populations and their roles in regenerative healing; and determining critical design factors that promote immature AF progenitor phenotypes and inform cell delivery strategies.

概括 约 40% 的背痛病例是由椎间盘 (IVD) 退变引起的。结构性 IVD 缺陷 区分退化和衰老，并在疼痛和残疾中发挥作用。有一个未满足的关键需求 自椎间盘切除术以来改进的纤维环（AF）修复策略，椎间盘切除术是去除椎间盘的金标准治疗方法 AF 缺损引起的髓核 (NP) 组织突出，导致 AF 缺损无法修复并引发并发症 包括再疝和复发性变性相关疼痛。虽然 IVD 细胞疗法的临床试验表明 承诺减少椎间盘源性疼痛和残疾，它们不涉及优化的交付策略，并且不 由于对 AF 细胞的多样性知之甚少，因此受到自然 IVD 愈合过程的影响 人群及其在康复中的作用。我们认为需要 IVD 再生愈合模型来识别 成功的 AF 治疗策略并确定成功的关键细胞和微机械因素 愈合作为再生医学治疗的路线图。我们已经开发成功了 小鼠再生 AF 愈合模型，并显示严重 AF 穿刺的新生儿 IVD 完全愈合 恢复 IVD 高度和生物力学特性，同时成人治愈纤维化沉积和 IVD 损失 身高和生物力学功能。该项目的前提是新生儿在康复的同时 骨骼成熟的小鼠由于细胞外基质（ECM）硬度增加和配体改变而不会 导致 AF 祖细胞终末分化的呈现。目标 1 确定增长的效果， 成熟度和基质硬度对 IVD 愈合的影响，并决定再生窗口何时关闭。我们 应用小鼠模型来确定 AF 再生愈合窗口关闭的出生后年龄，如果 完全的 AF 结构再生是可能的，并且如果改变 ECM 刚度可以延长再生时间 AF 细胞有丝分裂时的愈合窗口并延长年龄。目标 2 识别不同的 AF 祖细胞 种群、成熟过程中的损失以及这些祖细胞在愈合中的作用。我们使用单细胞和空间 对小鼠 IVD 进行测序，以识别不同的 AF 细胞群及其在再生小鼠中的定位 愈合、再生后愈合和再生恢复组。 Aim 3 设计了一种软合成材料 促进未成熟 AF 细胞表型的底物。我们确定小鼠和人类 ECM 的设计标准 和细胞并使用功能化聚乙二醇控制基质硬度、配体类型和密度 基材。该项目的成果包括确定 IVD 再生修复窗口何时关闭以及 是否可以完全再生；识别分散的 AF 祖细胞群及其在再生中的作用 康复;确定促进未成熟 AF 祖细胞表型的关键设计因素并提供信息 细胞递送策略。