Synovial Tissue Of RA Patients Research Articles

Upregulated miR-146b-3p predicted rheumatoid arthritis development and regulated TNF-α-induced excessive proliferation, motility, and inflammation in MH7A cells

BackgroundRheumatoid arthritis (RA) is a chronic immune system disease with a high disability rate threatening the living quality of patients. Identifying potential biomarkers for RA is of necessity to improve the prevention and management of RA.ObjectivesThis study focused on miR-146b-3p evaluating its clinical significance and revealing the underlying regulatory mechanisms.Materials and methodsA total of 107 RA patients were enrolled, and both serum and synovial tissues were collected. Another 78 osteoarthritis patients (OA, providing synovial tissues), and 72 healthy individuals (providing serum samples) were enrolled as the control group. The expression of miR-146b-3p was analyzed by PCR and analyzed with ROC and Pearson correlation analyses evaluating its significance in diagnosis and development prediction of RA patients. In vitro, MH7A cells were treated with TNF-α. The regulation of cell proliferation, motility, and inflammation by miR-146b-3p was assessed by CCK8, Transwell, and ELISA assays.ResultsSignificant upregulation of miR-146b-3p was observed in serum and synovial tissues of RA patients, which distinguished RA patients and were positively correlated with the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), anti-cyclic citrullinated peptide antibodies (anti-CCP), and rheumatoid factor (RF) of RA patients. TNF-α promoted the proliferation and motility of MH7A cells and induced significant inflammation in cells. Silencing miR-146b-3p alleviated the effect of TNF-α and negatively regulated the expression of HMGCR. The knockdown of HMGCR reversed the protective effect of miR-146b-3p silencing on TNF-α-stimulated MH7A cells.ConclusionsIncreased miR-146b-3p served as a biomarker for the diagnosis and severity of RA. Silencing miR-146b-3p could suppress TNF-α-induced excessive proliferation, motility, and inflammation via regulating HMGCR in MH7A cells.

SMAD2 inhibits pyroptosis of fibroblast-like synoviocytes and secretion of inflammatory factors via the TGF-β pathway in rheumatoid arthritis

ObjectiveRheumatoid arthritis (RA) is a chronic, progressive autoimmune disease. Over-activation of fibroblast-like synoviocytes is responsible for the hyperplasia of synovium and destruction of cartilage and bone and pyroptosis of FLS plays a key role in those pathological processes during RA. This study investigated the detailed mechanisms that SMAD2 regulates the pyroptosis of FLS and secretion of inflammatory factors in rheumatoid arthritis.MethodsWe collected synovial tissues of RA patients and FLS-RA and cultured FLS for detection of expression of SMAD2. ASC, NLRP3, cleaved-caspase-1, and GSDMD-N were detected by Western blot after overexpression of SMAD2. Besides, flow cytometry, electron microscope, ELISA, HE staining, and Safranin O staining were performed to further demonstrate that SMAD2 can affect the pyroptosis of FLS-RA.ResultsThe expression of SMAD2 was down-regulated in synovial tissues of RA patients and FLS-RA. Overexpression of SMAD2 can inhibit the expression of ASC, NLRP3, cleaved-caspase-1, and GSDMD-N. Flow cytometry and electron microscope further demonstrated that SMAD2 attenuated pyroptosis of FLS-RA. In addition, overexpression of SMAD2 also inhibited inflammatory factors such as IL-1β, IL-18, IL-6, and IL-8 secretion and release of LDH. Besides, overexpression of SMAD2 can reverse the decrease of p-SMAD2 and TGF-TGF-β induced by nigericin. In vivo experiments on CIA rats further demonstrated that overexpression of SMAD2 by local intra-articular injection of LV-SMAD2 can effectively alleviate joint redness, swelling, and destruction of cartilage and bones.ConclusionSMAD2 inhibited FLS-RA pyroptosis by down-regulating of NLRP3 inflammasomes (NLRP3, ASC, and caspase-1 complex) and eased the secretion of inflammatory factors via the TGF-β signaling pathway, thereby improving the symptom of RA. We hope that this study may provide a new research idea for RA and a potential target for the treatment of RA.

Circ_0002984 promotes proliferation, migration and inflammatory cytokine secretion and inhibits apoptosis of rheumatoid arthritis fibroblast-like synoviocytes by inducing PCSK6 through miR-543

BackgroundRheumatoid arthritis (RA) is inflammatory arthritic disease, and circular RNA is involved in RA development. The aim of the present work is to analyze the role of circ_0002984 in the process of RA fibroblast-like synoviocytes (RAFLSs) and the underlying mechanism.MethodsCirc_0002984, miR-543, and proprotein convertase subtilisin/kexin type 6 (PCSK6) expression levels were analyzed by quantitative real-time polymerase chain reaction or western blotting. Cell proliferation, migration, inflammatory response, and apoptosis were investigated through 5-Ethynyl-2′-deoxyuridine assay, wound-healing assay, enzyme-linked immunosorbent assay, and flow cytometry analysis. Dual-luciferase reporter assay and RNA immunoprecipitation assay were performed to assess the binding relationship.ResultsCirc_0002984 and PCSK6 expression were increased, while miR-543 expression was decreased in the synovial tissues of RA patients and RAFLSs. Circ_0002984 introduction facilitated RAFLS cell proliferation, migration and inflammatory response and repressed apoptosis, but circ_0002984 knockdown had an opposite role. Circ_0002984 targeted miR-543, and PCSK6 was targeted by miR-543. MiR-543 downregulation or PCSK6 overexpression restored the effects of circ_0002984 interference on RAFLS phenotypes.ConclusionCirc_0002984 promoted RAFLS proliferation, migration and inflammatory cytokine secretion and inhibited apoptosis by binding to miR-543 to induce PCSK6 production, providing a potential target for RA therapy.

HIF-1α dependent RhoA as a novel therapeutic target to regulate rheumatoid arthritis fibroblast-like synoviocytes migration in vitro and in vivo.

The purpose of this work is to investigate how the Rho family of GTPases A (RhoA) mediates the pathogenesis of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). The expression of RhoA in the synovial tissues of RA and Healthy people (Control) was detected using immunohistochemistry methods. The expression of RhoA and hypoxia-inducible factor-1α (HIF-1α) is inhibited by small interfering RNAs (siRNAs). The inhibition effect on RA-FLS migration was further investigated. The protein expression level of HIF-1α, RhoA, focal adhesion kinase (FAK), and myosin light chain (MLC) was also analysed using western blotting (WB). DBA1 mice were immunised with the mixture of bovine type II collagen and Freund's adjuvant to establish collagen induced arthritis (CIA) mouse model. Lip-siRhoA is administered through joint injection every two days. Micro-computed tomography (micro-CT) was used to detect mouse ankle joint destruction and evaluate the bone loss of the periarticular side. Destruction of the ankle articular cartilage was tested by histology. Expressions of P-RhoA, P-FAK and P-MLC in the ankle joint was detected by immunohistochemistry assay. The expression level of RhoA in the synovial tissues of RA patients was significantly higher than that in control group. Hypoxia was able to up-regulate the expression of RhoA. Whereas, HIF-1α siRNA (siHIF-1α) could down-regulate the expression of RhoA. Additionally, both of siHIF-1α and RhoA siRNA (siRhoA) delivered by liposome (Lip-siHIF-1α and Lip-siRhoA) were found to suppress FAK and MLC phosphorylation in vitro. In CIA mouse model, Lip-siRhoA was demonstrated to ameliorate the destruction of ankle joint and reduce the severity of ankle joint cartilage damage by micro-CT and histological staining, respectively. Therefore, inhibition of FLS cell migration can protect articular bone from destruction. Furthermore, the expression of P-RhoA, P-FAK and P-MLC was evaluated and found to be down-regulated by Lip-siRhoA in vivo. The results demonstrated that under hypoxic environment, HIF-1α dependent RhoA pathway played an important role on cytoskeleton remodelling and RA-FLS migration. Through down-regulating RhoA expression, it could effectively treat RA in vitro and in vivo. Our study provides new evidence for the potential clinical application of RhoA as a candidate for the treatment of RA.

HOXA5 is a key regulator of class 3 semaphorins expression in the synovium of rheumatoid arthritis patients.

Class 3 semaphorins are reduced in the synovial tissue of RA patients and these proteins are involved in the pathogenesis of the disease. The aim of this study was to identify the transcription factors involved in the expression of class 3 semaphorins in the synovium of RA patients. Protein and mRNA expression in synovial tissue from RA and individuals at risk (IAR) patients, human umbilical vein endothelial cells (HUVEC) and RA fibroblast-like synoviocytes (FLS) was determined by ELISA, immunoblotting and quantitative PCR. TCF-3, EBF-1 and HOXA5 expression was knocked down using siRNA. Cell viability, migration and invasion were determined using MTT, calcein, wound closure and invasion assays, respectively. mRNA expression of all class 3 semaphorins was significantly lower in the synovium of RA compared with IAR patients. In silico analysis suggested TCF-3, EBF-1 and HOXA5 as transcription factors involved in the expression of these semaphorins. TCF-3, EBF-1 and HOXA5 silencing significantly reduced the expression of several class 3 semaphorin members in FLS and HUVEC. Importantly, HOXA5 expression was significantly reduced in the synovium of RA compared with IAR patients and was negatively correlated with clinical disease parameters. Additionally, TNF-α down-regulated the HOXA5 expression in FLS and HUVEC. Finally, HOXA5 silencing enhanced the migratory and invasive capacities of FLS and the viability of HUVEC. HOXA5 expression is reduced during the progression of RA and could be a novel therapeutic strategy for modulating the hyperplasia of the synovium, through the regulation of class 3 semaphorins expression.

The Role of Histone Deacetylase and Histone Deacetylase Inhibitors in Rheumatoid Arthritis

Rheumatoid Arthritis or RA disease is a chronic inflammatory and systemic disease associated with broad synovitis resulting in erosion of the articular cartilage and marginal bone causing joint damage. RA is an autoimmune disease with the discovery of an autoantibody, namely rheumatoid factor. The relevant antibody is anti-citrullinated protein (ACPA) antibody. Citullination on the introduction of several proteins such as fibrin, vimentin, fibronectin, collagen type II, which is expressed in the synovial membrane during inflammation by ACPA. In a recent study increased HDAC activity in the synovial tissue of RA patients has increased. Histone deacetylase or abbreviated as HDAC is an enzyme that is important in regulating gene transcription by altering the acetylation of histone proteins which results in an important regulation of repression in the implementation of inflammation. HDAC enzyme inhibitor (HDACi) is an HDAC enzyme inhibitor that can provide benefits for the treatment of various diseases including malignancy and inflammation. In inflammatory disease HDACi overcomes inflammatory cytokines such as TNF-α, IL-6 and IL-1β. One of the HDAC classes is HDAC1 which is highly expressed in the synovial fibroblasts of RA patients. HDACi can burden swollen joints, reduce mononuclear cell infiltration, request pannus orders, inhibit bone and cartilage damage.

Notch‐1 and Notch‐3 Mediate Hypoxia‐Induced Activation of Synovial Fibroblasts in Rheumatoid Arthritis

To fully understand the molecular mechanism of hypoxia-induced rheumatoid arthritis synovial fibroblast cell (RASFC) activation via Notch-1 and Notch-3 signalling, and to evaluate its potential as a therapeutic target. Notch-1 and Notch-3 intracellular domain (N1ICD), Notch-3 intracellular domain (N3ICD), and hypoxia-inducible factor-1α (HIF-1α) were detected in RA synovial tissues via immunohistology. RASFC were cultured under hypoxic and normoxic conditions with or without small interfering RNAs, and N1ICD and N3ICD were overexpressed under normoxic conditions. Collagen-induced arthritis (CIA) rats were administered with LY411575 (inhibition of N1ICD and N3ICD) for 15 and 28 days, and its therapeutic efficacy was assessed by histology, radilology and inflammatory cytokine detection. In the study, we found that N1ICD, N3ICD and HIF-1α were abundantly expressed in RA patient synovial tissues. Meanwhile, HIF-1α was found to directly regulate the expression of Notch-1 and Notch-3 genes under hypoxic conditions. Moreover, hypoxia induced N1ICD and N3ICD expression in RASFC was blocked by HIF-1α small interfering RNA (siHIF-1α).Notch-1 small interfering RNA (siNotch-1) and Notch-3 small interfering RNA (siNotch-3) inhibited hypoxia-induced RASFC invasion and angiogenesis in vitro, whereas N1ICD and N3ICD overexpression promoted these processes. In addition, it was revealed that Notch-1 regulates RASFC migration and epithelial-mesenchymal transition (EMT) under hypoxia, whereas Notch-3 regulates anti-apoptosis and autophagy. Further, in vivo studies showed that N1ICD and N3ICD inhibitor LY411575 had a therapeutic effect on CIA rats. Collectively, this study has identified a functional link between HIF-1α, Notch-1, and Notch-3 signalling in regulating RASFC activation and rheumatoid arthritis.

Blocking Jak/STAT signalling using tofacitinib inhibits angiogenesis in experimental arthritis

ObjectiveDuring rheumatoid arthritis (RA), the angiogenic processes, occurring with pannus-formation, may be a therapeutic target. JAK/STAT-pathway may play a role and the aim of this work was to investigate the inhibiting role of a JAK-inhibitor, tofacitinib, on the angiogenic mechanisms occurring during RA.MethodsAfter ethical approval, JAK-1, JAK-3, STAT-1, STAT-3 and VEGF expression was evaluated on RA-synovial-tissues. In vitro, endothelial cells (ECs), stimulated with 20 ng/ml of VEGF and/or 1 μM of tofacitinib, were assessed for tube formation, migration and proliferation, by Matrigel, Boyden chamber assay and ki67 gene-expression. In vivo, 32 mice received collagen (collagen-induced arthritis (CIA)) and 32 mice PBS (control). At day 19, CIA and controls mice were divided: 16 mice receiving vehicle and 16 mice receiving tofacitinib. At day 35, the arthritis score, the thickness of paw joints and the serum levels of VEGF and Ang-2 were evaluated.ResultsThe expression of JAK-1, JAK-3, STAT-1, STAT-3 and VEGF in synovial tissue of RA-patients were significantly higher than healthy controls. In vitro, tofacitinib inhibited the ECs ability to form vessels, to proliferate and to migrate. In vivo, administration of tofacitinib prevented the increase of the arthritis score, the paw thickness, the synovial vessels and VEGF and Ang-2 serum-accumulation, when compared to CIA without tofacitinib.ConclusionsWe explored the anti-angiogenic role of tofacitinib, reporting its ability to inhibit in vitro the angiogenic mechanisms of ECs and in vivo the formation of new synovial vessels, occurring in CIA model. These findings suggest that the therapeutic effect of tofacitinib during RA may be also related to its anti-angiogenic activity.

The effects of miR-26b-5p on fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) via targeting EZH2

ObjectiveTo study the possible effects of miR-26b-5p on fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) through targeting enhancer of zeste homolog 2 (EZH2). MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-26b-5p and EZH2 expressions in synovial tissues of RA patients and healthy controls. Dual luciferase reporter assay was adopted to verify the targeting relationship between miR-26b-5p and EZH2. RA-FLS was divided into Blank, mimics NC, mimics, NC siRNA, EZH2 siRNA and inhibitors + EZH2 siRNA groups, followed by the assessment of proliferation, apoptosis, migration and invasion. The expression of genes and proteins in RA-FLS was tested by qRT-PCR and western blotting, respectively. ResultsMiR-26b-5p expression was lower, while EZH2 expression was higher in synovial tissue of RA patients than healthy controls; and miR-26b-5p was negatively correlated with the EZH2 in synovial tissue of RA patients, which were both related with disease activities. MiR-26b-5p can target EZH2 in RA-FLS. In vitro, miR-26b-5p mimics down-regulated EZH2 expression in RA-FLS. Compared with EZH2 siRNA group, the miR-26b-5p expression in inhibitors + EZH2 siRNA group was reduced, but EZH2 expression was increased. EZH2 siRNA inhibited the proliferation, invasion and migration of RA-FLS, promoted cell apoptosis, and inhibited the expression of TNF-α, IL-1β, IL-6, IL-17, MMP-2, MMP-9, which were reversed by miR-26b-5p inhibitor. ConclusionMiR-26b-5p may affect the biological characteristics of RA-FLS via targeting EZH2, including proliferation, apoptosis, invasion and migration, as well as the secretion of cytokines, thus playing a potential therapeutic role in RA.

Effect of MiR-21 on Regulating the Proliferation of Synovial Fibroblasts in Rheumatoid Arthritis

Background: This study investigated whether miR-21 regulates the expression of STAT3 and affects FLS cells. Methods: MiR-21 and STAT3 mRNA level was assessed by qRT-PCR and STAT3 and p-STAT3 level was evaluated by Western blot. Spearman correlation was used to analyze the relationship between miR-21 and STAT3 mRNA expression in synovial tissue of RA patients. FLS cells were treated with IL-17A, and the cells without treatment was included as the control group. Under IL-17A treatment, FLS cells were divided into 2 groups: miR-NC group and miR-21 mimic group. MiR-21, STAT3, p-STAT3 expression were detected and compared. EdU staining was used to detect cell proliferation and flow cytometry was used to measure cell apoptosis. Results: There was a target relationship of miR-21 with STAT3 mRNA. IL-17A treatment significantly downregulated miR-21 in FLS cells, upregulated STAT3 and p-STAT3 and enhanced cell proliferation. Transfection of miR21 mimic significantly downregulated STAT3 and p-STAT3 in FLS cells, reduced cell proliferation and increased cell apoptosis. Conclusion: MiR-21 overexpression down-regulates STAT3, inhibits FLS cell proliferation and promotes apoptosis, indicating that it might be a therapeutic target for treating RA.

MicroRNA-421 promotes inflammatory response of fibroblast-like synoviocytes in rheumatoid arthritis by targeting SPRY1.

The aim of this study was to investigate whether microRNA-421 could participate in the proliferative, migratory and inflammatory changes of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis by targeting SPRY1. The expressions of microRNA-421 and SPRY1 in synovial tissues and FLS were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot, respectively. The binding condition between microRNA-421 and SPRY1 was verified by the Dual-Luciferase reporter gene assay. MicroRNA-421 mimics and inhibitor were constructed and transfected. The levels of extracellular interleukin-1 (IL-1), IL-6, and COX2 in FLS after microRNA-421 mimics or inhibitor transfection were detected by enzyme-linked immunosorbent assay (ELISA). The regulatory effect of microRNA-421 on the proliferation and migration of FLS was detected using cell counting kit-8 (CCK-8) and transwell assay, respectively. Furthermore, collagen-induced RA mouse model was constructed to confirm the specific effect of microRNA-421 on regulating RA development. MicroRNA-421 was highly expressed in the synovial tissues of RA patients. SPRY1 expression in FLS was negatively regulated by microRNA-421. Moreover, the overexpression of microRNA-421 significantly promoted proliferative, invasive potentials and inflammatory response of FLS. In vivo, RA mouse model indicated that downregulated microRNA-421 and upregulated SPRY1 were observed in mice injected with cortisone and microRNA-421 inhibitor when compared with those of controls. MicroRNA-421 promotes the inflammatory response of fibroblast-like synoviocytes in rheumatoid arthritis by downregulating the SPRY1 expression.

MiR-138 activates NF-κB signaling and PGRN to promote rheumatoid arthritis via regulating HDAC4

BackgroundRheumatoid arthritis (RA) is a common immune-related disease worldwide, which is characterized by impaired fibroblast-like synoviocytes (FLS) proliferation and increased release of inflammatory cytokines. Unfortunately, the detailed mechanism by which miR-138-modulated rheumatoid arthritis has not been fully understood. MethodsRT-qPCR was used to examined mRNA level of various genes and western blot was utilized to probe protein level of acetylated H3, p-p62 and IκBα. For cytokines detection, we used ELISA method to measure the extracellular level of these cytokines. Bioinformatic tool and dual-luciferase reporter assay were employed to predict and confirm the downstream target of miR-138. ResultsmiR-138 was upregulated in serum and synovial tissues of RA patients. Moreover, Increased miR-138 was observed in LPS-treated FLS cells. HDAC4 was shown as the direct target of miR-138 and could be negatively regulated by miR-138. miR-138 and HDAC4 were involved in RA-related inflammatory cytokines release of FLS cells. Next, we revealed NF-κB and PGRN were significantly modulated by HDAC4 and miR-138 in an acetylation-dependent manner. More importantly, IκBα depletion and PGRN overexpression had the ability to rescue miR-138 inhibitor-attenuated inflammatory cytokines release of FLS cells. ConclusionHere, we reveal miR-138 regulates RA-related inflammatory cytokines in rheumatoid arthritis through HDAC4/PGRN or HDAC4/NF-κB. Our findings uncover a new molecular mechanism implicated in rheumatoid arthritis, which may accelerate development of therapeutical strategy by targeting this mechanism.

Promotion of macrophage activation by Tie2 in the context of the inflamed synovia of rheumatoid arthritis and psoriatic arthritis patients.

ObjectiveTo examine the role of Tie2 signalling in macrophage activation within the context of the inflammatory synovial microenvironment present in patients with RA and PsA.MethodsClinical responses and macrophage function were examined in wild-type and Tie2-overexpressing (Tie2-TG) mice in the K/BxN serum transfer model of arthritis. Macrophages derived from peripheral blood monocytes from healthy donors, RA and PsA patients, and RA and PsA synovial tissue explants were stimulated with TNF (10 ng/ml), angiopoietin (Ang)-1 or Ang-2 (200 ng/ml), or incubated with an anti-Ang2 neutralizing antibody. mRNA and protein expression of inflammatory mediators was analysed by quantitative PCR, ELISA and Luminex.ResultsTie2-TG mice displayed more clinically severe arthritis than wild-type mice, accompanied by enhanced joint expression of IL6, IL12B, NOS2, CCL2 and CXCL10, and activation of bone marrow-derived macrophages in response to Ang-2 stimulation. Ang-1 and Ang-2 significantly enhanced TNF-induced expression of pro-inflammatory cytokines and chemokines in macrophages from healthy donors differentiated with RA and PsA SF and peripheral blood-derived macrophages from RA and PsA patients. Both Ang-1 and Ang-2 induced the production of IL-6, IL-12p40, IL-8 and CCL-3 in synovial tissue explants of RA and PsA patients, and Ang-2 neutralization suppressed the production of IL-6 and IL-8 in the synovial tissue of RA patients.ConclusionTie2 signalling enhances TNF-dependent activation of macrophages within the context of ongoing synovial inflammation in RA and PsA, and neutralization of Tie2 ligands might be a promising therapeutic target in the treatment of these diseases.

Astrocyte elevated gene-1 promotes inflammation and invasion of fibroblast-like synoviocytes in rheumatoid arthritis.

Astrocyte elevated gene-1 (AEG-1) was initially induced by HIV-1 infection and involved in tumor progression, migration and invasion as a nuclear factor-κB (NF-κB)-dependent gene. The present study we intended to investigate the protein expression of AEG-1 significantly associated with rheumatoid arthritis. Western blot analysis and immunohistochemistry demonstrated that AEG-1 was upregulated in synovial tissue of RA patients compared with the controls. Double immunofluorescent staining suggested that AEG-1 was expressed in fibroblast-like synoviocytes (FLS) of RA patients. Furthermore, the expression of AEG-1 in FLS was increased in time-dependent manner by TNF-α stimulation. Upon TNF-α-treated FLS, AEG-1 transferred from the cytoplasm to nucleus where it interacted with the p65 subunit of NF-κB, as examined by immunoprecipitation and immunofluorescent staining assay. Moreover, the inhibition of AEG-1 by RNA interference significantly suppressed TNF-α-induced IL-6 and MMP-3 expression, leading to attenuation of FLS migration and invasion and markedly decreased the phosphorylation of P65 and IκBα, as well as AKT in FLS. Collectively, Our findings provided evidence that AEG-1 contributed to the production of inflammatory cytokines, migration and invasion of RA FLS, and underscored the importance of AEG-1 in the inflammation process of RA.

Identification of dysregulated genes in rheumatoid arthritis based on bioinformatics analysis.

BackgroundRheumatoid arthritis (RA) is a chronic auto-inflammatory disorder of joints. The present study aimed to identify the key genes in RA for better understanding the underlying mechanisms of RA.MethodsThe integrated analysis of expression profiling was conducted to identify differentially expressed genes (DEGs) in RA. Moreover, functional annotation, protein–protein interaction (PPI) network and transcription factor (TF) regulatory network construction were applied for exploring the potential biological roles of DEGs in RA. In addition, the expression level of identified candidate DEGs was preliminarily detected in peripheral blood cells of RA patients in the GSE17755 dataset. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to validate the expression levels of identified DEGs in RA.ResultsA total of 378 DEGs, including 202 up- and 176 down-regulated genes, were identified in synovial tissues of RA patients compared with healthy controls. DEGs were significantly enriched in axon guidance, RNA transport and MAPK signaling pathway. RBFOX2, LCK and SERBP1 were the hub proteins in the PPI network. In the TF-target gene network, RBFOX2, POU6F1, WIPF1 and PFKFB3 had the high connectivity with TFs. The expression status of 11 candidate DEGs was detected in GSE17755, the expression levels of MAT2A and NSA2 were significantly down-regulated and CD47 had the up-regulated tendency in peripheral blood cells of patients with RA compared with healthy individuals. qRT-PCR results of MAT2A, NSA2, CD47 were compatible with our bioinformatics analyses.DiscussionOur study might provide valuable information for exploring the pathogenesis mechanism of RA and identifying the potential biomarkers for RA diagnosis.

Effect of 10-hydroxycamptotbecine on the expression of VEGF in rheumatoid arthritis synovial fibroblasts

To study the effect of 10-Hydroxycamptotbecine (10-HCPT) on the expression of vascular endothelial growth factor (VEGF) in rheumatoid arthritis synovial fibroblasts (RASFs). RASFs were isolated form synovial tissue of RA patients and cultured in vitro. 10-HCPT (3.0×10(-6) mol/L, 3.0×10(-5) mol/L) and Methotrexate (MTX) (2.0×10(-6) mol/L, 2.0×10(-5) mol/L) with different concentrations were used to treat RASFs for 48 hours, and RASFs without 10-HCPT and MTX treatment were served as the control group. The level of VEGF in the supernatant of RASFs culture was measured by enzyme linked immunosorbent assay (ELISA). Compared with control group, high and low dose 10-HCPT groups showed significant values on the effect of inhibiting the expression of VEGF in RASFs. Compared with low-dose MTX group, both high and low dose 10-HCPT groups showed significant difference (P<0.05); compared with high-dose MTX group, the high-dose 10-HCPT group had significant difference (P<0.05). Compared with MTX, 10-HCPT showed significant effect on inhibiting the expression of VEGF in RASFs.

OP0224 Th17 Cells and TFH Cells and their Cytokine Products Are Enriched in the Synovium of Rheumatoid Arthritis Patients and Correlate with Disease Activity

BackgroundRheumatoid arthritis (RA) and osteoarthritis (OA) patients are affected by joint degradation caused by autoimmune pathology and cartilage loss, respectively. The balance between effector and regulatory T cell subsets that...

The arginine deminase PAD2 is activated by ATP-induced P2X7R signaling in mast cells and modulates the disease course in an inflammatory arthritis model (BA3P.208)

Abstract Rheumatoid arthritis is a chronic, systemic inflammatory disease. Citrulline-containing proteins are generated through posttranslational modification of arginine residues in a reaction catalyzed by the Ca2+-dependent peptidyl arginine deiminases or PAD enzymes. Plasma and synovial biopsy specimens from RA patients contain high levels of citrullinated proteins. PAD2 is highly expressed in synovial tissue of RA patients, in close association with citrullinated protein deposits, and its expression correlates with inflammation intensity. The process by which PAD2 is activated and contributes to protein citrullination during RA is unknown. We have identified mast cells as a major source of the PAD2 enzyme. Activation of the P2X7 purinergic receptor by the inflammatory “danger” signal ATP induces PAD2 activity and robust protein citrullination in mast cells. P2X7-mediated activation of PAD2 is sensitive to p38 MAPK and protein kinase C inhibitors, and PAD2 regulates the expression of the TNFR2, Adamts-9, and Rab6b transcripts in mast cells. The PAD2 enzyme and its citrullinated substrate proteins are released from mast cells on activation with ATP. Importantly, mast cells have been shown to play a key role in the development of RA. Our results suggest that P2X7 activation of mast cells may play a role in inflammation by providing PAD2 and PAD2 substrates access to the extracellular space.

Expression of FcRL4 defines a pro-inflammatory, RANKL-producing B cell subset in rheumatoid arthritis

ObjectivesThe success of B cell targeting therapies has highlighted the importance of B cells in rheumatoid arthritis pathogenesis. We have previously shown that B cells in the RA synovium are...

SAT0064 The expression of HDAC6 is reduced in rheumatoid arthritis synovial fibroblasts

BackgroundSince rheumatoid synovial cells produce large amounts of various cytokines and proteases, up to 30% of all newly synthesized proteins are unfolded, leading to a cellular stress condition. Histone-deacetylase (HDAC)...