Pathogenesis of Inflammation-driven Intervertebral Disc Herniation: The Role of Syndecan 4

炎症驱动的椎间盘突出症的发病机制：Syndecan 4 的作用

• 批准号: 9754682
• 负责人: Makarand V Risbud
• 金额: $ 46.25万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9754682
• 关键词: ADAMTS; Address; American; Animal Model; Animals; Apoptosis; Back; Back Pain; Biomechanics; CXCL12 gene; Catabolism; Cell Aging; Cell surface; Cells; Chronic; Collagen; Defect; Disease; Etiology; Fibronectins; Foundations; Future; Genes; Goals; Heparan Sulfate Proteoglycan; Heparitin Sulfate; Human; IL8 gene; Immune; Immune Cell Activation; Incidence; Individual; Infiltration; Inflammation; Inflammatory; Interleukin-1 beta; Intervention; Intervertebral disc structure; Investigation; Lead; Learning; Link; Low Back Pain; MMP3 gene; Macrophage Activation; Magnetic Resonance Imaging; Matrix Metalloproteinases; Measures; Mediating; Mediator of activation protein; Molecular; Molecular Structure; Motion; Mus; Neck Pain; Occupations; Outcome Study; Pain; Pathogenesis; Pathway interactions; Phase; Play; Process; Production; Property; Proteoglycan; RANTES; Regulation; Role; Side; Signal Transduction; Slipped Disk; Solid; Stromal Cell-Derived Factor 1; Stromelysin 1; Structure; TNF gene; Testing; Time; Tissues; Transgenic Mice; Trauma; Unspecified or Sulfate Ion Sulfates; Vertebral column; Work; aggrecan; aggrecanase; cell motility; chemokine; cytokine; disability; discogenic pain; experience; human tissue; in vivo; inflammatory milieu; intervertebral disk degeneration; loss of function; macrophage; migration; mutant; new therapeutic target; novel; nucleus pulposus; overexpression; prevent; protein degradation; stem; syndecan-4; syndecan4; synergism; therapy development; transcriptome sequencing

The relationship between the etiology of intervertebral disc degeneration and low back pain has been subjected to considerable scrutiny. Degeneration is thought to be initiated by the abnormal production of a number of pro-inflammatory cytokines, in particular TNF-α and IL-1β. While these studies have shown involvement of cytokines in pathogenesis of disc degeneration and herniation, progress has been slow in delineating new therapeutic targets to block inflammation. This deficit stems from our lack of understanding of molecular mediators that regulate and link cytokine-dependent matrix degradation with immune cell migration into the disc through annular defects. Interestingly, our ongoing work has found an unexpected synergism between heparan sulfate (HS) proteoglycan syndecan4 (SDC4) and these two key inflammatory cytokines. The goal of the proposed investigations is to build on the central role of SDC4 in the pathogenesis of the disc herniation and inflammation. We have formulated two interrelated hypotheses each of which addresses a separate but linked phase of the disease process. The first phase relates to the effect of the inflammatory cytokines on the regulation of aggrecan rich matrix degradation. We will test the hypothesis that SDC4 through HS side chains promotes cytokine-dependent aggrecan rich matrix degradation through ADAMTS and MMP activation. Using gain and loss-of-function studies of SDC4 in NP cells treated with cytokines and RNA-Seq approach we will identify novel SDC4 responsive genes. We will also measure the contribution of MMPs, ADAMTS-1 and ADAM17 produced by NP cells in SDC4 shedding. In addition, we will determine how changes in SDC4 levels relate to aggrecan and collagen turnover in human tissues. The second stage of the disease process is characterized by structural changes in the NP and AF and formation of annular tears and herniations. We propose to test the hypothesis that that in inflammatory milieu of the herniated disc, SDC4 plays an important role in macrophage activation and migration by controlling the activity of select chemokines (CCL5, IL-8 and SDF-1) secreted by the disc cells. This will be achieved using primary macrophages isolated from SDC4-/- mice. Using well characterized painful human disc tissues, we will link changes in chemokines and SDC4 levels to immune cell activation, infiltration and matrix degradation. Finally, to explore the in vivo importance of SDC4 in pathogenesis of TNF--driven disc herniation, we will cross hTNFtg mice with SDC4 -/- animals to generate hTNFtg,SDC4-/- mice. To establish if a deficiency in SDC4 provides protection against cytokine-dependent disc herniation, we will compare molecular, structural and biomechanical properties of the motion segments with that of hTNFtg. To our knowledge, this would be the first attempt to address the contribution of SDC4 to mechanisms linking initiation and propagation of the degenerative cascade and herniation driven by inflammatory cytokines. These studies will provide a foundation for future development of interventional strategies to target SDC4 dependent catabolic and inflammatory phases of degenerative disc disease.

椎间盘退变的病因与腰痛之间的关系一直受到关注 进行严格审查。退化被认为是由许多细胞的异常产生引起的 促炎细胞因子，特别是 TNF-α 和 IL-1β。虽然这些研究表明参与 细胞因子在椎间盘退变和突出症发病机制中的作用，在描述新的进展方面进展缓慢 阻断炎症的治疗目标。这种缺陷源于我们对分子生物学缺乏了解。 调节细胞因子依赖性基质降解与免疫细胞迁移至免疫细胞并将其联系起来的介质 椎间盘穿过环形缺陷。有趣的是，我们正在进行的工作发现了意想不到的协同作用 硫酸乙酰肝素 (HS) 蛋白聚糖 syndecan4 (SDC4) 和这两种关键的炎症细胞因子。目标是 拟议的研究是基于 SDC4 在椎间盘突出发病机制中的核心作用 和炎症。我们提出了两个相互关联的假设，每个假设都解决了一个单独但 疾病过程的相关阶段。第一阶段涉及炎症细胞因子对 富含聚集蛋白聚糖的基质降解的调节。我们将测试 SDC4 通过 HS 侧链的假设 通过 ADAMTS 和 MMP 激活促进细胞因子依赖性富含聚集蛋白聚糖的基质降解。使用 在用细胞因子和 RNA-Seq 方法处理的 NP 细胞中进行 SDC4 功能获得和丧失的研究，我们将 鉴定新的 SDC4 反应基因。我们还将衡量 MMP、ADAMTS-1 和 ADAM17 由 NP 细胞在 SDC4 脱落时产生。此外，我们将确定SDC4水平如何变化 与人体组织中的聚集蛋白聚糖和胶原蛋白周转有关。疾病过程的第二阶段是 其特征是 NP 和 AF 的结构变化以及环状撕裂和疝出的形成。我们 提议检验以下假设：在椎间盘突出的炎症环境中，SDC4 发挥重要作用 通过控制选定趋化因子（CCL5、IL-8 和 SDF-1)由椎间盘细胞分泌。这将使用从 SDC4-/- 小鼠中分离的原代巨噬细胞来实现。 使用特征明确的人类椎间盘疼痛组织，我们将趋化因子和 SDC4 水平的变化与 免疫细胞激活、浸润和基质降解。最后探讨SDC4在体内的重要性 在 TNF-α 驱动的椎间盘突出症的发病机制中，我们将 hTNFtg 小鼠与 SDC4 -/- 动物杂交以产生 hTNFtg，SDC4-/- 小鼠。确定 SDC4 缺陷是否能提供针对细胞因子依赖性椎间盘的保护作用 疝出，我们将比较运动节段的分子、结构和生物力学特性 hTNFtg 的。据我们所知，这将是首次尝试解决 SDC4 对 连接退行性级联和疝出的启动和传播的机制 炎症细胞因子。这些研究将为未来介入治疗的发展奠定基础。 针对退行性椎间盘疾病的 SDC4 依赖性分解代谢和炎症阶段的策略。