Pathogenic Mechanisms in Spondyloarthritis

脊柱关节炎的发病机制

基本信息

批准号：
9352004
负责人：
Robert Colbert
金额：
$ 362.17万
依托单位：
NATIONAL INSTITUTE OF ARTHRITIS AND MUSCULOSKELETAL AND SKIN DISEASES
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9352004
关键词：
Accounting Adaptor Signaling Protein Address Adipocytes Adolescent Adult Affect Alleles American Animal Model Ankylosing spondylitis Arthritis Back Cell Death Cell Lineage Cell surface Cells Child Childhood Chronic Childhood Arthritis Classification Clinical Colitis Collaborations Complex Development Development Plans Disease Disease Progression Environment European Exhibits Fibroblasts Frequencies Gene Expression Profiling Genes Genetic Germ-Line Mutation Goals Guidelines HLA-B Antigens HLA-B27 Antigen HLA-B7 Antigen Hematopoietic Heritability Histology Human IL12B gene Image Immunologic Deficiency Syndromes Individual Inflammation Inflammatory Interleukin-1 Interleukin-17 International Knowledge Laboratories Light Link Lymphoma Membrane Potentials Mesenchymal Stem Cells Mitochondria Monitor Mutation Myeloid Cells Osteoblasts Osteogenesis Outcome Pathogenesis Patients Penetrance Peptides Phenotype Play Population Predisposition Process Production Publishing Rattus Receptor Signaling Recommendation Research Rheumatism Rheumatology Role STAT3 gene Sendai virus Severities Single-Gene Defect Spondylarthritis Susceptibility Gene Symptoms Syndrome TYK2 Testing Time Transgenic Organisms Variant Work abstracting autoinflammatory base bone cell type chemokine cohort college cytokine early onset evidence based guidelines functional genomics gain of function gain of function mutation gastrointestinal genetic variant genome wide association study genome-wide gut microbiome gut microbiota improved indexing induced pluripotent stem cell interest interleukin-23 knock-down loss of function loss of function mutation meetings microbial microbial community microbiome microbiota mitochondrial membrane monocyte neutrophil non-genetic overexpression peripheral blood prospective rare variant research study risk variant tool validation studies

项目摘要

Development of Classification Criteria for Juvenile Axial Spondyloarthritis and Treatment Recommendations for Axial Spondyloarthritis in Adults In collaboration with Pam Weiss, we worked to develop and validate a disease activity index for juvenile SpA (JSpADA). The JSpADA index discriminates between subjects with active versus inactive disease and is responsive to worsening in disease activity over time. Prospective validation studies are planned. In addition, our collaboration continues with the planned development of classification criteria that identify children with JSpA who have axial arthritis (sacroiliitis). This is an international effort engaging pediatric rheumatology and criteria development experts from the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). We contributed to a large ACR-sponsored project to provide evidence-based recommendations for the treatment of adult patients with ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis. These recommendations serve as guidelines for managing common clinical situations, although additional work is needed to establish best practices for treatment over time and monitoring disease progression. The Microbiome and Spondyloarthritis Considerable evidence suggests gut microbiota play a role in the development and severity of spondyloarthritis. We demonstrated previously that HLA-B27 and human 2-microglobulin (h2m) affect the gut microbiome in an animal model of human SpA. This preliminary work provided the basis for an in-depth study asking whether specific microbial communities are altered by HLA-B27 and are linked to the development and severity of colitis in this animal model. We examined effects of HLA-B27 on 3 genetic backgrounds that alter the penetrance of disease, from the complete absence of inflammation to severe early onset disease, and have surprising results linking the effects of different microbial communities to development of SpA in a background/environment specific fashion. Preliminary results have been presented at rheumatology and microbiome meetings. These studies will enable us to build and test hypotheses to understand how normal commensal microbiota influence SpA pathogenesis. Functional Genomics of ERAP1 To evaluate ERAP1-HLA-B27 interactions, ERAP1 expression was knocked down in monocytic cells. This led to the accumulation of aberrant forms of HLA-B27 on the cell surface, including complexes with long peptides as well as properly folded heavy chain-peptide-2m complexes. In contrast, no differences in the accumulation of other HLA-B alleles (B51 and B18) were observed. These results suggest that normal levels and/or activity of ERAP1 are necessary to maintain the integrity of cell surface HLA-B27 complexes in monocytes, and that certain alleles may be more susceptible to the effects of ERAP1. To further assess ERAP1-HLA-B27 functional interactions in disease, we produced gene-edited rats that lack ERAP1 expression. Cohorts of HLA-B27 transgenic (B27-Tg), HLA-B7 transgenic (B7-Tg), and wild type rats, with (ERAP1+/+, ERAP1+/-) and without (ERAP1-/-) ERAP1 were generated and monitored over 6 months to determine the frequency and severity of gastrointestinal inflammation and arthritis. Preliminary results show that ERAP1 deficiency confers protection from the development of arthritis in B27-Tg rats, while the clinical severity of gastrointestinal inflammation was unaffected although histology scores were increased slightly. Effects of ERAP1 deficiency on normal and abnormal features of HLA-B27 and their consequences are also being evaluated. These experiments suggest that ERAP1 loss-of-function is protective for arthritis in SpA, and are expected to shed light on mechanisms by which HLA-B27 contributes to disease pathogenesis. Preliminary results have been published in abstract form and have been presented at national and international meetings. Induced Pluripotent Stem Cells Aberrant bone formation in AS is poorly understood, but involves cell types that are not readily accessible for study. To circumvent this obstacle a major goal of our research has been to develop induced pluripotent stem cells (iPSCs) that can be differentiated into mesenchymal stem cells (MSCs) and their derivatives including bone-forming osteoblasts. We have demonstrated the feasibility of reprogramming patient fibroblasts into iPSCs using non-integrating Sendai virus-encoded factors, and have differentiated these cells into multiple disease-relevant cell lineages including MSCs, mineralizing osteoblasts, adipocytes, and myeloid cells. Genome-wide gene expression analysis shows that the expression of several AS risk genes is enriched in MSCs, with some also prominent in iPSCs, supporting the utility of this approach. The ability to generate iPSCs provides a powerful tool to explore the functional genomics of AS risk genes that may impact bone formation and other aspects of disease pathogenesis. Mechanisms of IL-1 Production Mutations in the NLRP3 inflammasome cause a group of autoinflammatory diseases known as cryopyrin-associated periodic syndromes (CAPS), the most severe form of which is NOMID. Inappropriate overproduction of IL-1 is a key pathogenic mechanism. We identified the predominant cell type (CD14hi/CD16low) responsible for IL-1 overproduction in peripheral blood in patients with NOMID, and demonstrated that these cells die rapidly following stimulation in a process known as pyronecrosis, a pro-inflammatory form of cell death. Current studies suggest that IL-1 release and cell death are dependent on mitochondrial STAT3, which appears to alter the mitochondrial membrane potential. Genetic Contributions to Juvenile Arthritis MyD88 is a critical adaptor protein for TLR and IL-1 receptor signaling. Germline loss-of-function mutations in MyD88 cause severe immunodeficiency, while somatic gain-of-function mutations have been linked to certain lymphomas. We discovered a de novo germline MYD88 mutation in a child with early onset destructive polyarticular juvenile idiopathic arthritis (JIA). Cells from the patient overexpress chemokines and cytokines at baseline, and fibroblasts hyper-respond to IL-1. Culture supernatants exhibit strikingly enhanced neutrophil chemotactic activity. The MyD88 mutation is sufficient to increase NF-B activity and cause overexpression of chemokines and cytokines in monocytic cells. Thus, this germline mutation produces gain-of-function effects in MyD88 in hematopoietic as well as non-hematopoietic cells that are likely to contribute to the development of destructive arthritis. This work has been presented in abstract form at a national meeting, and studies are underway to understand how the mutation leads to a complex arthritis phenotype. Nevertheless, these results support a role for single gene defects contributing to the pathogenesis of JIA.

开发成人青少年轴向脊椎关节炎的分类标准和轴向脊椎关节炎的治疗建议与Pam Weiss合作，我们致力于开发和验证少年水疗中心（JSPADA）的疾病活动指数。 JSPADA索引区分了活跃疾病与非活性疾病的受试者，并且对随着时间的推移疾病活动的恶化有反应。计划了前瞻性验证研究。此外，我们的合作始于计划的分类标准的计划开发，这些标准鉴定患有轴向关节炎（sacroiliisis）的JSPA儿童。这是一项国际努力，吸引了美国风湿病学院（ACR）和欧洲反风湿主义联盟（EULAR）的小儿风湿病学和标准发展专家。我们为一个大型ACR赞助的项目做出了贡献，该项目提供了基于证据的建议，以治疗成年患者的强直性脊柱炎（AS）和非放置轴向轴向脊柱肝炎。这些建议是管理常见临床情况的指南，尽管需要额外的工作来建立随着时间的时间治疗和监测疾病进展的最佳实践。微生物组和脊椎关节炎大量证据表明，肠道菌群在脊椎关节炎的发育和严重程度中起作用。我们先前证明了HLA-B27和人2-微球蛋白（H2M）会影响人类水疗中动物模型的肠道微生物组。这项初步工作为深入研究提供了基础，询问HLA-B27是否改变了特定的微生物群落，并与该动物模型中结肠炎的发展和严重程度有关。我们检查了HLA-B27对3种改变疾病渗透率的3种遗传背景的影响，从完全没有炎症到严重的早期发作疾病，并具有令人惊讶的结果，将不同微生物群落与背景/环境特定方式的SPA发展联系起来。在风湿病学和微生物组会议上已经提出了初步结果。这些研究将使我们能够构建和检验假设，以了解正常的共生微生物群如何影响水疗发病机理。 ERAP1的功能基因组学为了评估ERAP1-HLA-B27相互作用，在单核细胞中敲低ERAP1的表达。这导致了异常形式的HLA-B27在细胞表面的积累，其中包括具有长肽的复合物以及正确折叠的重链肽-2M复合物。相反，没有观察到其他HLA-B等位基因（B51和B18）的积累差异。这些结果表明，ERAP1的正常水平和/或活性对于维持单核细胞中细胞表面HLA-B27复合物的完整性是必要的，并且某些等位基因可能更容易受到ERAP1的影响。为了进一步评估疾病中的ERAP1-HLA-B27功能相互作用，我们产生了缺乏ERAP1表达的基因编辑的大鼠。 HLA-B27转基因（B27-TG），HLA-B7转基因（B7-TG）和野生型大鼠的队列，具有（ERAP1+/+，ERAP1 +/-），以及（ERAP1+/+，ERAP1 +/-），并在6个月内生成（ERAP1 - / - ）ERAP1，以确定频率和严重性的频率和严重性的炎症和Arptraintical interthestinalsitical和Arthramprymation和Arthristitis。初步结果表明，ERAP1缺乏症赋予了B27-TG大鼠关节炎发展的保护，而胃肠道炎症的临床严重程度却不受影响，尽管组织学评分略有提高。 ERAP1缺乏对HLA-B27正常和异常特征及其后果的影响也得到了评估。这些实验表明，ERAP1功能丧失对水疗中的关节炎具有保护作用，并有望阐明HLA-B27有助于疾病发病机理的机制。初步结果以摘要形式发布，并在国家和国际会议上提出。诱导多能干细胞众所周知，异常的骨形成是不容易访问的细胞类型。为了避免这一障碍，我们研究的主要目标是开发可分化为间充质干细胞（MSC）及其衍生物在内的诱导多能干细胞（IPSC），包括骨形成骨细胞。我们已经证明了使用非整合仙台病毒编码的因子将患者成纤维细胞重编程为IPSC的可行性，并将这些细胞区分为多种疾病的细胞谱系，包括MSC，包括MSC，矿物质化成骨细胞，脂肪细胞和髓样细胞。全基因组基因表达分析表明，几种作为风险基因的表达富含MSC，其中一些在IPSC中也很突出，支持了这种方法的实用性。产生IPSC的能力为探索AS的功能基因组学提供了强大的工具，该功能基因组可能影响骨骼形成和疾病发病机理的其他方面。 IL-1生产的机理 NLRP3炎性体中的突变引起一组称为冷冻蛋白相关的周期综合征（CAP）的自身炎性疾病，其中最严重的形式是Nomid。 IL-1的不当过量生产是一种关键的致病机制。我们确定了NOMID患者的主要细胞类型（CD14HI/CD16LOW），导致外周血中IL-1过量产生过量产生，并证明这些细胞在称为吡朗期的过程中迅速死亡，这种刺激是一种称为吡朗期的刺激，一种细胞死亡的促炎形式。当前的研究表明，IL-1释放和细胞死亡取决于线粒体STAT3，这似乎改变了线粒体膜电位。对青少年关节炎的遗传贡献 MyD88是用于TLR和IL-1受体信号传导的关键衔接蛋白。 MyD88的种系功能丧失突变会导致严重的免疫缺陷，而运动获得突变已与某些淋巴瘤有关。我们在一个早期发作破坏性多关节特发性关节炎（JIA）的儿童中发现了从头种系Myd88突变。来自患者的细胞过表达基线时的趋化因子和细胞因子，成纤维细胞对IL-1进行超反应。培养上清液表现出明显增强的中性粒细胞趋化活性。 MYD88突变足以增加NF-B活性并导致单核细胞中趋化因子和细胞因子过度表达。因此，这种种系突变会在造血和非造血细胞中产生MyD88的功能效果，这可能有助于破坏性关节炎的发展。这项工作是在全国会议上以抽象形式提出的，并且正在进行研究以了解突变如何导致复杂的关节炎表型。然而，这些结果支持导致JIA发病机理的单基因缺陷的作用。