Fibrosis, inflammation, and osteophyte formation in post-traumatic osteoarthritis

创伤后骨关节炎中的纤维化、炎症和骨赘形成

基本信息

批准号：
10570315
负责人：
Alexander John Knights
金额：
$ 10.31万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10570315
关键词：
ATAC-seq Acceleration Actins Affect Agonist Arthritis Automobile Driving Binding Bioinformatics Biological Assay Biology Bone Growth Bone Spur Cartilage Cell Nucleus Cell Surface Receptors Cells Characteristics Chondrocytes Chronic Clinical Research Complex Coupled Data Degenerative polyarthritis Development Disease Fibroblasts Fibrosis G-Protein-Coupled Receptors Goals Health Human Hypertrophy Immune In Vitro Inflammation Inflammatory Injections Injury Interleukin-6 Joints Kinetics Knee Knockout Mice Knowledge acquisition Label Leucine-Rich Repeat Link Macrophage Macrophage Activation Mediating Mentorship Molecular Molecular Biology Molecular Immunology Multimodal Imaging Mus Musculoskeletal Myofibroblast Osteoblasts Osteogenesis Outcome Pain Pathogenesis Pathogenicity Pathologic Pathology Patient-Focused Outcomes Phase Population Positioning Attribute Process Proteins Proteoglycan Reporter Reporter Genes Research Role Science Secondary to Severities Signal Pathway Signal Transduction Smooth Muscle Synovial Cell Synovial Fluid Synovial Membrane Synovitis Technical Expertise Testing Tissues Training Transgenic Organisms Traumatic Arthropathy Vocational Guidance Work arthropathies articular cartilage beta catenin bone career cartilage degradation cell type cytokine disability effective therapy improved inducible Cre injured insight joint function joint injury mineralization multiple omics neutralizing antibody novel osteochondral tissue osteogenic pain sensitivity pharmacologic preclinical study progenitor receptor single nucleus RNA-sequencing single-cell RNA sequencing skill acquisition skills transcriptome sequencing

项目摘要

Post-traumatic osteoarthritis (PTOA) is a degenerative joint disease that arises after injury and affects millions worldwide. There are currently no disease-modifying treatments. PTOA is a complex, multi-tissue joint disease characterized by pain, cartilage degradation, synovial inflammation and fibrosis, and formation of ectopic bone growths called osteophytes. The inherent complexity of this disease is a barrier to developing effective treatments, as little is known about the intricate tissue crosstalk that underlies PTOA progression. Our long- term goal is to uncover and comprehensively characterize cellular and molecular mechanisms central to key pathological sequalae of PTOA: synovial fibrosis, inflammation, and osteophyte formation. We will focus on canonical Wnt/β-catenin (cWnt) signaling. cWnt overactivation has recently been implicated as a driving factor of arthritis. Our data show that the cWnt signaling agonist R-spondin 2 (Rspo2) is strongly induced in multiple joint tissues during PTOA, and that Rspo2 alone is sufficient to induce pathological features characteristic of PTOA. Using single-cell RNA-seq, we profiled synovium of mice with PTOA and found that Rspo2 is produced by synovial lining fibroblasts. We identified a novel population of pro-fibrotic cells that arise after injury and express Lgr cell surface receptors for Rspo2. We showed that synovial fibroblasts respond to Rspo2 by secreting cytokines that in turn activate pro-inflammatory macrophages (known to drive synovial pathology in PTOA). Single-cell profiling also revealed a novel subset of injury-induced, Lgr-expressing osteochondral progenitors in synovium, which we propose give rise to osteophytes. We hypothesize that Rspo2-driven cWnt signaling mediates pathological crosstalk between joint-resident cell types to potentiate PTOA. To test this, our aims in the K99 phase are to: 1) determine the role of Rspo2-driven cWnt signaling in the emergence and function of pro-fibrotic synovial cells during PTOA using transgenic reporter mice, multi-omic analyses, and in vitro differentiation assays, and 2) characterize crosstalk between cWnt-active synovial fibroblasts and pro- inflammatory macrophages, using knockout mice and crosstalk assays. To extend upon my molecular biology and immunology expertise, I will receive rigorous technical and conceptual training from my diverse mentorship committee during the K99 phase, and valuable career guidance. This expert training in bioinformatics; cWnt signaling; bone, cartilage, and synovial biology; and multi-modal imaging, will be crucial for carrying out my K99 aims and especially critical for successfully launching my independent career. These skills will be utilized in my R00 phase to: 3) determine how Rspo2/Lgr signaling promotes osteophyte formation in PTOA, using tissue-specific deletion and reporter mice, and in vitro differentiation assays. This work will significantly extend our understanding of cellular and molecular mechanisms that underpin synovial fibrosis, inflammation, and osteophyte formation in PTOA. These insights will have meaningful, tangible outcomes for human health, by accelerating development of effective disease-modifying treatments for PTOA sufferers.

创伤后骨关节炎（PTOA）是一种退化性关节疾病，受伤后出现并影响数百万全世界。目前尚无疾病改良治疗。 PTOA是一种复杂的多组织关节疾病具有疼痛，软骨降解，滑膜注射和纤维化的特征以及生态骨的形成生长称为骨植物。这种疾病的继承复杂性是发展有效的障碍对PTOA进展的复杂组织串扰的处理知之甚少。我们的长期术语目标是揭示并全面地表征关键中心的细胞和分子机制 PTOA的病理序列：滑膜纤维化，感染和骨植物形成。我们将重点关注规范的Wnt/β-catenin（CWNT）信号传导。 CWNT过度活化最近被暗示为驱动因素关节炎。我们的数据表明，CWNT信号传导激动剂R-Spondin 2（RSPO2）在多个中强烈诱导 PTOA期间的关节组织，仅RSPO2就足以诱导病理特征的特征 PTOA。使用单细胞RNA-seq，我们用PTOA对小鼠的滑膜进行了分析，发现RSPO2被产生通过滑膜成纤维细胞。我们确定了新的促纤维细胞群体，这些细胞在受伤后出现， RSPO2的表达LGR细胞表面受体。我们表明滑膜成纤维细胞对RSPO2作出反应分泌细胞因子，而细胞因子反过 PTOA）。单细胞分析还揭示了损伤诱导的表达LGR的新型骨软骨滑膜中的祖细胞，我们建议这会产生骨植物。我们假设RSPO2驱动的CWNT 信号传导介导联合居民细胞类型之间的病理串扰为潜在的PTOA。为了测试这一点，我们 K99阶段的目的是：1）确定RSPO2驱动的CWNT信号在出现中的作用使用转基因报道小鼠，多运动分析和在PTOA期间促纤维化滑膜细胞的功能体外分化测定，2）表征CWNT活性滑膜成纤维细胞和pro-之间的串扰使用基因敲除小鼠和串扰测定法。扩展我的分子生物学和免疫学专业知识，我将从我的多样性心态中获得严格的技术和概念培训在K99阶段的委员会和宝贵的职业指导。这种生物信息学专家培训； CWNT 信号传导；骨，软骨和滑膜生物学；和多模式成像，对于执行我的 K99的目的是成功启动我的独立职业至关重要。这些技能将被利用在我的R00阶段至：3）确定使用PTOA中的Rspo2/LGR信号如何促进骨植物形成组织特异性缺失和报告基因小鼠，以及体外分化测定。这项工作将大大扩展我们对基础滑膜纤维化，注射和基础的细胞和分子机制的理解 PTOA中的骨植物形成。这些见解将对人类健康产生有意义的，有形的结果，加速对PTOA患者的有效疾病改良治疗的发展。