Roles of the superficial zone in mature articular cartilage

浅表区在成熟关节软骨中的作用

• 批准号: 10704023
• 负责人: Danielle Renae Rux
• 金额: $ 9万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-14 至 2023-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10704023
• 关键词: Ablation; Acute; Address; Adolescent; Adolescent and Young Adult; Adult; Affect; Alleles; Antigens; Articular Range of Motion; Biological; Biology; Candidate Disease Gene; Cartilage Diseases; Cell Communication; Cell Count; Cell Death; Cell Lineage; Cell Proliferation; Cell physiology; Cells; Cellular Assay; Cessation of life; Characteristics; Chondrocytes; Cilia; Clinical; Data; Degenerative polyarthritis; Deterioration; Development; Diphtheria Toxin; Disease; Embryo; Embryonic Development; Foundations; Future; Gene Expression Profile; Growth; Growth and Development function; Histology; Image; In Situ Hybridization; Injury; Intervention; Joint Capsule; Joints; Knee; Knowledge; Label; Lead; Life; Link; LoxP-flanked allele; Lubricants; Lubrication; Maintenance; Mechanics; Medial meniscus structure; Modeling; Movement; Multiple Abnormalities; Mus; Neonatal; Pathologic; Pathology; Pattern; Perception; Phase; Phenotype; Population; Predisposition; Prevention; Proliferating; Property; Proteoglycan; Quality of life; Recovery; Reporter; Research; Role; Running; Signal Transduction; Solid; Structure; Synovial joint; Testing; Therapeutic; Thinness; Time; Tissues; Tomatoes; Transgenic Organisms; Traumatic Arthropathy; Traumatic injury; Work; age related; analytical tool; arthropathies; articular cartilage; career; cartilage development; cartilage repair; confocal imaging; environmental change; experimental study; fibroblast growth factor 18; in vivo; insight; joint function; mature animal; mechanical load; mechanical signal; mineralization; mosaic; mouse model; mutant; nanoindentation; nanomechanics; nanoscale; postnatal; postnatal development; progenitor; repaired; resilience; response; sedentary; single-cell RNA sequencing; skeletal movement; smoothened signaling pathway; subchondral bone; targeted treatment; transcriptome sequencing; translational medicine

PROJECT SUMMARY/ABSTRACT Synovial joints are essential for full range of motion and quality of life. Unfortunately, the joints -and articular cartilage in particular- are highly susceptible to congenital-, injury- and age-related diseases that lead to degeneration, a reflection of poor intrinsic cartilage repair capacity. Current clinical interventions do not meet the wide range of demands on articular cartilage due, in large part, to lack of crucial knowledge on the cellular mechanisms that govern normal functions of articular cartilage such as lubrication and tissue maintenance growing adolescents and young adults. In order to advance these strategies, more information is needed on basic mechanisms of articular cartilage development and adaptation/response to environmental changes in vivo. The superficial most layer of articular cartilage is responsible for secreting proteoglycans (lubricants) into the joint capsule that allow for frictionless movement. Many studies have focused on this as their primary function, and increasing lubrication has shown promise for disease treatment. This project will take a broader approach to clearly define unique characteristics and other potential functions for these cells that could be targeted for therapeutic approaches. In particular, this study will focus on interactions of superficial zone cells with underlying articular chondrocytes. Developmental studies by my sponsor's lab and preliminary data I have gathered from adult mice provide strong evidence that the superficial zone does not function as a progenitor population for underlying articular chondrocytes, and instead suggests that superficial cells are unique from articular chondrocytes. Thus, I hypothesize that superficial zone cells are maintained distinctly in articular cartilage, but that their coordinated functions with underlying articular chondrocytes promote sustained, functional organization of articular cartilage. To test this hypothesis, in Aim 1 I will characterize the unique properties of superficial zone cells during growth and during their response to damage compared to articular chondrocytes. In Aim 2, I will directly test the requirement of the superficial zone cells in adult animals. In Aim 3, I will explore mechanisms of coordinated functions between superficial cells and articular chondrocytes to maintain mature articular cartilage structure. I will use multiple analytical tools including histomorphometry, confocal imaging, and nano-scale mechanical testing in combination with RNA sequencing and in situ hybridization. Conditional mouse models, including our transgenic Prg4CreER allele to target superficial zone cells, will be examined at adult stages and following a traumatic injury (DMM-model) that significantly alters mechanical loading in the joint. The proposed studies will provide essential knowledge on mechanisms that underlie superficial zone cell functions and responses to damage/altered mechanical load. The data and insights from the project will prove essential to envision and test future therapeutic joint strategies that target superficial zone cells, providing broad relevance and importance to the project and offering a solid platform on which to establish my independent career in biomedical and translational medicine research.

项目摘要/摘要 滑膜关节对于全面运动和生活质量至关重要。不幸的是，关节和关节 软骨特别容易受到先天性，损伤和年龄相关疾病的影响，导致 变性，反射不良的内在软骨修复能力。当前的临床干预措施不符合 在很大程度上，由于缺乏对细胞的关键知识，对关节软骨的广泛需求 控制关节软骨的正常功能的机制，例如润滑和组织维护 成长中的青少年和年轻人。为了推进这些策略，需要更多信息 关节软骨发展的基本机制以及适应/对环境变化的反应 体内。表面的大多数关节软骨层是将蛋白聚糖（润滑剂）分泌到 允许无摩擦运动的关节胶囊。许多研究都集中在他们的主要方面 功能和增加的润滑已经显示出对疾病治疗的希望。这个项目将更加广泛 明确定义这些细胞的独特特征和其他潜在功能的方法 针对治疗方法的目标。特别是，这项研究将集中于浅表区域的相互作用 带有基础的关节软骨细胞。我的赞助商实验室和初步数据的发展研究 从成年小鼠那里收集 用于基础关节软骨细胞的种群，而是暗示浅表细胞是独一无二的 关节软骨细胞。因此，我假设表面细胞在关节中明显保持 软骨，但它们与潜在的关节软骨细胞的协调功能促进了持续的， 关节软骨的功能组织。为了检验这一假设，在目标1中，我将描述独特 与关节相比 软骨细胞。在AIM 2中，我将直接测试成年动物表面细胞的需求。目标 3，我将探索表面细胞和关节软骨细胞之间协调功能的机制 保持成熟的关节软骨结构。我将使用多种分析工具，包括组织形态计量学， 共聚焦成像和纳米级机械测试与RNA测序结合和原位 杂交。有条件的小鼠模型，包括我们的转基因PRG4CREER等位基因靶向浅层区域 细胞将在成人阶段进行检查，并在创伤性损伤（DMM模型）之后显着改变 关节中的机械载荷。拟议的研究将提供有关机制的基本知识 浅表区细胞功能和对损伤/机械负荷改变的反应。数据和 该项目的见解将被证明是针对目标的设想和测试未来的治疗联合策略至关重要的 表面区域细胞，为项目提供广泛的相关性和重要性，并在 这是我在生物医学和转化医学研究方面的独立职业。