Project description:To address the regulation of interferon-stimulated genes expression by VGLL3 in fibroblast-like synoviocytes (FLS) of rheumatoid arthritis (RA) patients, VGLL3 was overexpressed in RA-FLS via a lentiviral vector. After four days of transfection, VGLL3-overexpressed RA-FLS and vector-transfected RA-FLS were subjected to RNA sequencing.
Project description:Rheumatoid arthritis (RA) fibroblast‐like synoviocytes (FLS) derived from hip and knee have distinctive DNA methylation and transcriptome patterns in interleukin (IL)‐6 signaling and Janus kinase (JAK)–signal transducers and activators of transcription (STAT) pathways. To determine the functional effects of these joint‐specific signatures, we evaluated how RA hip and knee FLS differ in their response to IL‐6.Hip or knee RA FLS were obtained after arthroplasty. Previously published datasets on epigenetic landscape of FLS were mined to identify joint‐specific IL‐6–related epigenomic differences. RNA sequencing was performed on five RA hip and five knee FLS treated with or without IL‐6. Differential gene expression was determined using edgeR software. STAT3 phosphorylation was measured using bead assays. Sensitivity to tofacitinib was evaluated by measuring CCL2 inhibition using quantitative polymerase chain reaction. Assay for Transposase‐Accessible Chromatin sequencing and histone chromatin immunoprecipitation sequencing datasets from RA FLS were analyzed to identify epigenomic differences between hip and knee. Differential chromatin accessibility was associated with IL‐6, IL‐6R, and JAK1 genes. H3K27ac was also differentially marked at other JAK‐STAT–related genes, including STAT3‐STAT5A region. Principal component analysis of RNA sequencing data confirmed segregation between RA hip and knee FLS under basal conditions, that persisted following IL‐6 treatment. STAT3 phosphorylation after IL‐6 was significantly higher in knee than hip FLS and was highly correlated with JAK1 protein levels. Knee FLS were less sensitive to the JAK inhibitor tofacitinib than hip FLS. RA hip and knee FLS have distinct transcriptomes, epigenetic marks, and STAT3 activation patterns in the IL‐6 pathway. These joint‐specific differences might contribute to a differential clinical response in individual joints to targeted therapies such as JAK inhibitors.
Project description:To determine the mechanism of abnormal activity of RA FLS, we have done some research and found out that lncRNA HASML and protein HuR have some effects on migration and invasion of RA FLS. To more deeply explore how HASML and HuR regulate the functions of RA FLS, RNA sequencing analysis was used to evaluate the transcriptome of siHASML and siHuR treatment and negative control (NC) group. A P-value less than 0.05 was considered significant.
Project description:Fibroblast-like synoviocytes (FLS) are crucial in promoting articular inflammation and destruction in rheumatoid arthritis (RA). As the most abundant RNA modification, the function of m6A in RA FLS is still unclear. Here, we constructed FTO-knockdown FLS to explore the mechanism of FTO in regulating the aggressive behavior of RA FLS.
Project description:Rheumatoid synoviocytes, which consist of fibroblast-like synoviocytes (FLS) and synovial macrophages (SM), are crucial for the progression of rheumatoid arthritis (RA). Particularly, FLS of RA patients (RA-FLS) exhibit invasive characteristics reminiscent of cancer cells, destroying cartilage and bone, although it remains unresolved how RA-FLS exhibit invasive phenotype. RA-FLS and SM originate differently from mesenchymal and myeloid cells, respectively, but share many pathologic functions. However, the molecular signatures and biological networks representing the distinct and shared features of the two cell types are unknown. Presently, we performed global transcriptome profiling of FLS and SM obtained from RA and osteoarthritis patients. By comparing the transcriptomes, we identified distinct molecular signatures and cellular processes defining invasiveness of RA-FLS and pro-inflammatory properties of RA synovial macrophages (RA-SM), respectively. Interestingly, under interleukin1β-stimulated condition, RA-FLS newly acquired pro-inflammatory signature mimicking RA-SM without losing invasive properties. We next reconstructed a network model that delineates the shared, RA-FLS-dominant (invasive), and RA-SM-dominant (inflammatory) processes. From the network model, we selected 13 genes, including POSTN and TWIST1, as novel regulator candidates responsible for FLS invasiveness. Of note, POSTN and TWIST1 expressions were elevated in independent RA-FLS and were further instigated by interleukin1β. In vitro functional assays demonstrated the requirement of POSTN and TWIST1 for migration and invasion of RA-FLS stimulated with interleukin1β. Taken together, our systems approach to rheumatoid synovitis provides a basis for identifying novel regulators responsible for pathological features of RA-FLS and RA-SM, demonstrating how a certain type of cells acquires functional redundancy under chronic inflammatory conditions. To identify molecular signatures of FLS and MLS in RA joints, we isolated FLS from synovial tissues of RA and osteoarthritis (OA) patients, obtained synovial macrophages from synovial fluid of RA patients, and differentiated control macrophages from peripheral blood of healthy subjects. Also, we stimulated FLS with IL1β, and then analyzed gene expression profiles of both IL1β-stimulated RA-FLS and OA-FLS
Project description:Rheumatoid arthritis (RA) is an inflammatory autoimmune disease affecting synovial joints and leading to cartilage damage and bone loss. This destruction is promoted by activated fibroblast-like synoviocytes (FLS) that show an invasive and migratory phenotype. The mechanisms of FLS activation are unknown, but evidence suggests that pre-damaged extracellular matrix (ECM) of the cartilage can trigger FLS activation. Integrin α11β1 might be involved in the activation, as it is highly increased in the synovium of RA patients and hTNFtg mice, an RA mouse model. Since TNFα is the major cytokine induced in RA, we treated murine chondrocytes with TNFα to produce a damaged, RA-like matrix. Comparison to healthy chondrocyte matrix revealed decreased ECM proteins, including several collagens and proteoglycans, increased matrix-degrading proteins and elevated levels of inflammatory cytokines. FLS responded to those differences in the damaged chondrocyte matrix with a matrix-remodeling and pro-inflammatory phenotype characterized by expressing genes involved in matrix degradation and increased production of CLL11 and CCL19. Damaged chondrocyte matrix induced increased Itga11 expression in FLS, which correlates with the increased α11β1 amounts in RA patients. FLS deficient in integrin α11β1 released lower amounts of inflammation-associated cytokines but did not reveal significant differences from the response of wild type FLS to a damaged, RA-like matrix. Our results demonstrate differences in healthy and RA-like chondrocyte ECM and distinctly different responses of wt FLS to damaged versus healthy ECM.
Project description:Rheumatoid synoviocytes, which consist of fibroblast-like synoviocytes (FLS) and synovial macrophages (SM), are crucial for the progression of rheumatoid arthritis (RA). Particularly, FLS of RA patients (RA-FLS) exhibit invasive characteristics reminiscent of cancer cells, destroying cartilage and bone, although it remains unresolved how RA-FLS exhibit invasive phenotype. RA-FLS and SM originate differently from mesenchymal and myeloid cells, respectively, but share many pathologic functions. However, the molecular signatures and biological networks representing the distinct and shared features of the two cell types are unknown. Presently, we performed global transcriptome profiling of FLS and SM obtained from RA and osteoarthritis patients. By comparing the transcriptomes, we identified distinct molecular signatures and cellular processes defining invasiveness of RA-FLS and pro-inflammatory properties of RA synovial macrophages (RA-SM), respectively. Interestingly, under interleukin1β-stimulated condition, RA-FLS newly acquired pro-inflammatory signature mimicking RA-SM without losing invasive properties. We next reconstructed a network model that delineates the shared, RA-FLS-dominant (invasive), and RA-SM-dominant (inflammatory) processes. From the network model, we selected 13 genes, including POSTN and TWIST1, as novel regulator candidates responsible for FLS invasiveness. Of note, POSTN and TWIST1 expressions were elevated in independent RA-FLS and were further instigated by interleukin1β. In vitro functional assays demonstrated the requirement of POSTN and TWIST1 for migration and invasion of RA-FLS stimulated with interleukin1β. Taken together, our systems approach to rheumatoid synovitis provides a basis for identifying novel regulators responsible for pathological features of RA-FLS and RA-SM, demonstrating how a certain type of cells acquires functional redundancy under chronic inflammatory conditions.
2014-01-09 | GSE49604 | GEO
Project description:small RNA suquencing in RA-FLS
Project description:Fibroblast-like synoviocyte (FLS) constitutes a major cell subset of rheumatoid arthritis (RA) joint. Dysregulation of microRNAs (miRNAs) contributes to FLS activation in the context of chronic inflammation. However, functional association of the miRNAs-targets relationships characterizing FLS phenotypes in RA has not been fully elucidated yet. Thus, we uncovered the novel miRNA-target interactions characterizing pathologic phenotypes of RA-FLS. We performed microarray analyses of miRNA in RA- and osteoarthritis (OA) FLS with or without interleukin-1β (IL-1β) stimulation. The miRNA-target prediction and network model-ing were performed using TargetScan and Cytoscape. Identified miRNA-target relationships and their cellular functions were validated in vitro.
Project description:Objectives: TNF-induced activation of fibroblast-like synoviocytes (FLS) is a critical determinant for synovial inflammation and joint destruction in rheumatoid arthritis (RA). The detrimental role of TNF-receptor 1 (TNFR1) has thoroughly been characterized. The contributions of TNFR2, however, are largely unknown. This study was performed to delineate the role of TNFR2 in human FLS activation. Methods: TNFR2 expression in synovial tissue samples was determined by immunohistochemistry. Expression of TNFR2 was silenced using RNAi or CRISPR/Cas9 technologies. Global transcriptional changes were determined by RNA-seq. QPCR, ELISA and immunoblotting were used to validate RNA-seq results and to uncover pathways operating downstream of TNFR2 in FLS. Results. TNFR2 expression was increased in RA when compared to OA synovial tissues. In particular, RA-FLS demonstrated higher levels of TNFR2 when compared to OA-FLS. TNFR2 expression in RA-FLS correlated with RA disease activity, synovial T- and B-cell infiltration. TNF and IL1 were identified as inflammatory mediators that upregulate TNFR2 in RA-FLS. Silencing of TNFR2 in RA-FLS markedly diminished the TNF-induced expression of inflammatory cytokines and chemokines, including CXCR3-binding chemokines and the B-cell activating factor TNFSF13B. Immunobiochemical analyses revealed that TNFR2-mediated expression of inflammatory mediators critically depends on STAT1. Conclusion: Our results define a critical role for TNFR2 in FLS-driven inflammation and unfold its participation in the unresolved course of synovial inflammation in RA.