Cellular and molecular mechanisms regulating synovial joint development

调节滑膜关节发育的细胞和分子机制

• 批准号: 10899096
• 负责人: Minwook Kim
• 金额: $ 7.32万
• 依托单位: ROWAN UNIVERSITY SCHOOL/OSTEOPATHIC MED
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10899096
• 关键词: Ablation; Adult; Anatomy; Appearance; Back; Biochemical; Biochemistry; Biological Assay; Biological Process; Biology; Biomedical Engineering; CD44 gene; Cell Adhesion Molecules; Cell Line; Cell Separation; Cell surface; Cells; Complement; Cytoskeletal Modeling; Data; Degenerative polyarthritis; Development; Developmental Biology; Digit structure; Disease; Embryo; Embryonic Development; Engineering; Enzymes; Extracellular Matrix; Genes; Germ Cells; Growth Factor; HAS2 gene; Homeostasis; Hyaluronan; Hyaluronic Acid; Hyaluronidase; Immobilization; Impairment; In Situ Hybridization; In Vitro; Individual; Inflammatory; Injections; Integral Membrane Protein; Joint by Site; Joints; Knee; Knee joint; Lead; Ligaments; Limb structure; Link; Liquid substance; LoxP-flanked allele; Lubricants; MAP2K1 gene; Maintenance; Mentored Research Scientist Development Award; Mentors; Mesenchymal; Metabolism; Molecular; Molecular Biology; Molecular Genetics; Molecular Weight; Morphology; Motion; Movement; Mus; Pathway interactions; Phenotype; Platelet-Derived Growth Factor beta Receptor; Play; Process; Property; Quality of life; Recombinants; Research; Role; Shapes; Shoulder; Signal Pathway; Signal Transduction; Site; Spectroscopy, Fourier Transform Infrared; Stress Fibers; Structure; Surface; Synovial Fluid; Synovial joint; System; Testing; Therapeutic; Time; Tissues; Toll-like receptors; Training; articular cartilage; capsule; career; cartilage regeneration; cartilaginous; clinically relevant; fetal; growth differentiation factor 5; infrared spectroscopy; insight; joint formation; joint function; lubricin; morphogens; mouse model; mutant; novel; novel therapeutics; physical separation; prospective; protective pathway; rational design; receptor; repaired; response; skeletal; skills; stem cell function; sugar; therapy design; tool; trait; transcriptome sequencing

Project Summary and Abstract Synovial joints are essential for body motion and quality of life. Their synovial cavity and lubricant-rich fluid permit unhindered joint motion and function and provide tissue protection and nourishment. While these aspects of synovial joint biology are well understood, little is known about how the cavity and its fluid actually develop during embryogenesis. At early fetal stages, the limb skeletal primordia are composed of continuous cartilaginous structures without joints. Joint development starts with appearance of an “interzone”, a tissue made of mesenchymal cells expressing the growth and differentiation factor 5 gene (Gdf5). We previously showed that Gdf5+ cell progenies produce most joint tissues over time and the synovial cavity forms in the middle of the interzone. Because the interzone cells are initially attached to each other, the cavitation process must involve their physical separation along the prospective articular line to facilitate the creation of a fluid-filled cavity. Previous studies indicated that interzone cells produce hyaluronan (HA) around the cavitation time, and this is accompanied by accumulation of a HA-rich matrix in local tissues. HA is a major component of extracellular matrix and synovial fluid and plays important roles in tissue homeostasis. In my preliminary studies, I found that just before cavitation onset, interzone cells in mouse embryo limbs express hyaluronan synthase 2 (HAS2, ‘the HA synthesizer’) and transmembrane protein 2 (TMEM2), a cell surface hyaluronidase that specifically cleaves high molecular weight HA into intermediate and biologically-active fragments. I also discovered that, morphologically, cavitation initiates with formation of microlumens along the prospective articular line and is completed soon afterwards when the pockets coalesce to generate a single one synovial cavity. This process is extremely rapid in the developing knee but is slower in digits. These and other novel data lead to my central hypothesis that joint cavitation is brought about by convergence of diverse but coordinated biological processes. Accordingly, Aim 1 is to determine the role of HAS2 and TMEM2 in joint cavitation using genetically modified mouse models. I will conditionally delete Has2 and/or Tmem2 in interzone cells (using Gdf5Cre mice) and subject resulting mutant embryos to detailed analysis. Aim 2 is to determine cellular and molecular mechanisms of cavitation. I will investigate downstream signaling pathways in response to changes in HA sizes and resulting interactions with cell surface CD44 receptor, regulating HA metabolism in synovial joint development and long-term maintenance. The project will provide novel insights into mechanisms underlying joint development and cavitation. In line with the K01 mechanism, the project will allow me to acquire new expertise in skeletal developmental and molecular biology and to integrate it with my previous training in bioengineering. This unique combination of expertise in two distinct but interrelated fields will allow me to establish an independent career distinct from my mentors and create novel therapeutic tools to repair and regenerate cartilage for the treatment of joint conditions such as osteoarthritis (OA).

项目概要和摘要 滑膜关节对于身体运动和生活质量至关重要。他们的滑液腔和富含润滑剂的液体 允许关节运动和功能不受阻碍，并提供组织保护和营养。虽然这些 尽管人们对滑膜关节生物学的各个方面都有很好的了解，但对腔及其流体如何实际上 在胚胎发生期间发育。在胚胎早期，四肢骨骼原基由连续的 没有关节的软骨结构。关节的发育始于“中间区”的出现， 由表达生长和分化因子5基因（Gdf 5）的间充质细胞制成。我们之前 显示Gdf 5+细胞后代随着时间的推移产生大多数关节组织，并且滑膜腔在关节中形成。 中间地带由于层间细胞最初是相互附着的， 必须涉及它们沿着预期关节线的物理分离，以便于创建充满液体的 腔先前的研究表明，在空化时间前后，层间细胞产生透明质酸（HA）， 这伴随着局部组织中富含HA的基质的积累。医管局是 细胞外基质和滑液，并在组织稳态中起重要作用。在我的初步调查中， 在研究中，我发现就在空化发生之前，小鼠胚胎四肢的间区细胞表达透明质酸 合成酶2（HAS 2，"HA合成酶“）和跨膜蛋白2（TMEM 2，细胞表面透明质酸酶 其特异性地将高分子量HA切割成中间和生物活性片段。我也 发现，在形态学上，空化开始与形成微管腔沿着的前景 关节线，并完成后不久，当口袋合并，以产生一个单一的滑膜 腔这一过程在发育中的膝关节中非常迅速，但在足趾中较慢。这些和其他小说 数据导致我的中心假设，联合空化是由不同的，但 协调的生物过程。因此，目的1是确定HAS 2和TMEM 2在关节炎中的作用。 使用转基因小鼠模型进行空化。我将有条件地删除interzone中的Has 2和/或Tmem 2 细胞（使用Gdf 5Cre小鼠），并对所得突变胚胎进行详细分析。目标2：确定 空化的细胞和分子机制。我将研究下游信号通路 HA大小的变化以及由此产生的与细胞表面CD 44受体的相互作用，调节HA代谢， 滑膜关节发育和长期维护。该项目将提供新的见解机制 潜在的联合发展和空化。根据K 01机制，该项目将允许我 获得骨骼发育和分子生物学方面的新专业知识，并将其与我以前的 生物工程培训。这两个不同但相互关联的领域的专业知识的独特组合将使 我建立一个独立的职业生涯不同于我的导师，并创造新的治疗工具，以修复 并再生软骨用于治疗关节疾病如骨关节炎（OA）。