Project description:The study presents: - an optimized synovium dissociation protocol for single cell RNA-sequencing studies of the human synovium. The protocol enables the isolation of high yield of viable synovial cells from prospectively collected fresh synovial biopsies from patients with inflammatory arthritis with a minimal sample droupout. The protocol is derived from the method for dissociation of cryopreserved synovia published by Donlin and colleagues (Arthritis Res. Ther. 2019). - a reference single-cell atlas of fresh human synovium in inflammatory arthritis, comprising more than 100´000 unsorted synovial scRNA-seq profiles from 27 freshly dissociated synovia of patients with different types of inflammatory arthritis. The synovial cells segregate into ten lymphoid, 14 myeloid and 17 stromal synovial cell populations and subpopulations, including synovial neutrophils, representing broadly representing the cellular heterogeneity and composition of the human synovium in inflammatory arthritis.
Project description:Rheumatoid arthritis (RA) induced destruction of knee joints is a common cause of total knee arthroplasty (TKA). Under single cell RNA sequencing generated by 10x Genomics, we identified CD142+ synovial fibroblasts as a novel cluster, located at the sublining layer in normal and osteoarthritis knee synovium, but elevated and distributed at the lining layer in RA knee synovium, and infiltrated in multiple RA joint synovia. Intra-articular injection of CD142+ synovial fibroblasts can quickly and drastically damage the meniscus but has a slight effect on cartilage.Long-term follow-up of the RA cohort indicated that enriched CD142+ synovial fibroblasts in the lining layer was a risk factor for severe joint destruction and eventually underwent TKA. Our results demonstrate that CD142+ synovial fibroblasts can be used as an indicator to assess prognosis and a therapeutic target to inhibit meniscal damage, thereby alleviating RA knee joint destruction.
Project description:This study aimed to understand the characteristics of synovium-infiltrating regulatory T cells (Treg) during arthritis. Treg cells were collected from the synovium and draining lymph nodes of arthritic mice. Treg cells of control draining lymph nodes were also subjected to the study.
Project description:recision use of targeted therapies is urgently needed to improve long-term clinical outcomes for children affected by inflammatory arthritis, known as Juvenile Idiopathic Arthritis. Progress has been obstructed by a lack of understanding of the cellular basis of joint inflammation in children, given the difficulties in obtaining and studying synovial tissue itself. To this end, we combine single-cell RNA-sequencing, multiplexed immunofluorescence imaging and spatial transcriptomics to define the cellular and transcriptomic landscape of the synovium in children with Juvenile Idiopathic Arthritis. We identify spatial niches of resident and infiltrating cell populations that correlate with the degree of inflammation, and gene programs associated with arthritis severity. Combined with analyses of synovial fluid and peripheral blood from the same children, we distinguish differences in cellular composition, signalling pathways and transcriptional programs across anatomical compartments. Whilst we identify several pathogenic populations shared with adult-onset arthritis, our analyses highlight increased vascularity of the inflamed developing joint and TGFb-driven stromal subsets that upregulate expression of disease risk-associated genes. Overall, these findings illustrate the need for treatment algorithms informed by a tissue-based classification of arthritis.
Project description:recision use of targeted therapies is urgently needed to improve long-term clinical outcomes for children affected by inflammatory arthritis, known as Juvenile Idiopathic Arthritis. Progress has been obstructed by a lack of understanding of the cellular basis of joint inflammation in children, given the difficulties in obtaining and studying synovial tissue itself. To this end, we combine single-cell RNA-sequencing, multiplexed immunofluorescence imaging and spatial transcriptomics to define the cellular and transcriptomic landscape of the synovium in children with Juvenile Idiopathic Arthritis. We identify spatial niches of resident and infiltrating cell populations that correlate with the degree of inflammation, and gene programs associated with arthritis severity. Combined with analyses of synovial fluid and peripheral blood from the same children, we distinguish differences in cellular composition, signalling pathways and transcriptional programs across anatomical compartments. Whilst we identify several pathogenic populations shared with adult-onset arthritis, our analyses highlight increased vascularity of the inflamed developing joint and TGFb-driven stromal subsets that upregulate expression of disease risk-associated genes. Overall, these findings illustrate the need for treatment algorithms informed by a tissue-based classification of arthritis.
Project description:Intent of this experiment is to define the baseline transcriptome of the synovium obtained from rheumatoid arthritis patients prior to initiation of DMARD (Disease-modifying antirheumatic drug) therapy and compare it with the synovial transcriptome of rheumatoid arthritis patients with an established disease profile.
Project description:Osteoarthritis (OA) causes pain and functional disability for over 500 million people worldwide and is characterized by progressive loss of cartilage and synovial hyperplasia from the articulating surfaces of diarthrodial joints. Although the etiology of the disease is unknown, it is widely accepted that these degenerative changes arise from an imbalance of synthetic and degradative pathways that control cartilage and synovium extracellular matrix metabolism. Genome-wide U133A Affymetrix oligonucleotide array set was used to comprehensively investigate the expression pattern in non-osteoarthritis (normal) and synovium obtained from OA and rheumatoid arthritis (RA) patients undergoing knee replacement surgery. This study was undertaken to understand the disease's molecular basis better and provide relevant insight into phenotypical alterations and mechanisms involved in OA pathogenesis.
Project description:Juvenile idiopathic arthritis (JIA) is the most prevalent chronic inflammatory arthritis of childhood, yet the spatial organization in the synovium remains poorly understood. Here, we perform subcellular-resolution spatial transcriptomic profiling of synovial tissue from patients with active JIA. We identify diverse immune and stromal cell populations and reconstruct spatially defined cellular niches. Applying a newly developed spatial colocalization analysis pipeline, we uncover microanatomical structures, including endothelial-fibroblast interactions mediated by NOTCH signaling, and a CXCL9/CXCR3 signaling axis between inflammatory macrophages and CD8+ T cells, alongside the characterization of other resident macrophage subsets. We also detect and characterize tertiary lymphoid structures marked by CXCL13/CXCR5 and CCL19-mediated signaling from Tph cells and immunoregulatory DCs, analogous to those observed in other autoimmune diseases. Finally, comparative analysis with rheumatoid arthritis reveals JIA-enriched cell states, including NOTCH3+ and CXCL12+ sublining fibroblasts, suggesting potentially differential inflammatory programs in pediatric versus adult arthritis. These findings provide a spatially resolved molecular framework of JIA synovitis and introduce a generalizable computational pipeline for spatial colocalization analysis in tissue inflammation.