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) 是一种退行性关节疾病，在受伤后出现，影响数百万人 PTOA 是一种复杂的多组织关节疾病，目前在世界范围内尚无缓解疾病的治疗方法。其特点是疼痛、软骨退化、滑膜炎症和纤维化以及异位骨的形成这种疾病固有的复杂性是有效发展的障碍。治疗，因为我们对 PTOA 进展背后的复杂组织串扰知之甚少。长期目标是揭示并全面表征关键的细胞和分子机制 PTOA的病理后遗症：滑膜纤维化、炎症和骨赘形成。典型的 Wnt/β-连环蛋白 (cWnt) 信号传导最近被认为是一个驱动因素。我们的数据表明，cWnt 信号激动剂 R-spondin 2 (Rspo2) 在多种疾病中被强烈诱导。 PTOA 期间的关节组织，并且单独的 Rspo2 足以诱发以下特征的病理特征： PTOA。使用单细胞 RNA-seq，我们对具有 PTOA 的小鼠滑膜进行了分析，发现产生了 Rspo2。我们发现了一种新的促纤维化细胞群，这些细胞在损伤和损伤后出现。表达 Rspo2 的 Lgr 细胞表面受体我们发现滑膜成纤维细胞通过 Rspo2 做出反应。分泌细胞因子，进而激活促炎巨噬细胞（已知可驱动滑膜病理学）单细胞分析还揭示了损伤诱导的、表达 Lgr 的骨软骨的新亚群。我们认为滑膜中的祖细胞会产生骨赘，我们勇敢地面对 Rspo2 驱动的 cWnt。信号传导介导联合驻留细胞类型之间的病理串扰以增强 PTOA 为了测试这一点。 K99 阶段的目标是：1) 确定 Rspo2 驱动的 cWnt 信号传导在出现和发生中的作用。使用转基因报告小鼠、多组学分析和在 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亲- 炎症巨噬细胞，使用基因敲除小鼠和串扰测定来扩展我的分子生物学。和免疫学专业知识，我将从多元化的指导中接受严格的技术和概念培训 K99 阶段的委员会，以及生物信息学领域的专家培训；信号传导；骨骼、软骨和滑膜生物学；以及多模态成像，对于开展我的研究至关重要。 K99 的目标对于成功开展我的独立职业生涯尤其重要。我将利用这些技能。在我的 R00 阶段：3) 确定 Rspo2/Lgr 信号如何促进 PTOA 中骨赘形成，使用组织特异性缺失和报告小鼠以及体外分化测定将显着扩展这项工作。我们对滑膜纤维化、炎症和滑膜纤维化的细胞和分子机制的理解 PTOA 中骨赘的形成，这些见解将为人类健康带来有意义、切实的成果。加速开发针对 PTOA 患者的有效疾病缓解疗法。