Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease caused by inflammatory cells. Various inflammatory cells involved in RA include fibroblast-like synoviocytes, macrophages, CD4⁺T-lymphocytes, B lymphocytes, osteoclasts and chondrocytes. The close interaction between various inflammatory cells leads to imbalance of immune response and disorder of the expression of mRNA in inflammatory cells. It helps to drive production of pro-inflammatory cytokines and stimulate specific antigen-specific T- and B-lymphocytes to produce autoantibodies which is an important pathogenic factor for RA. Competing endogenous RNA (ceRNA) can regulate the expression of mRNA by competitively binding to miRNA. The related ceRNA network is a new regulatory mechanism for RNA interaction. It has been found to be involved in the regulation of abnormal biological processes such as proliferation, apoptosis, invasion and release of inflammatory factors of RA inflammatory cells. Understanding the ceRNA network in 6 kinds of RA common inflammatory cells provides a new idea for further elucidating the pathogenesis of RA, and provides a theoretical basis for the discovery of new biomarkers and effective therapeutic targets.
Humans ; Arthritis, Rheumatoid/genetics* ; MicroRNAs/metabolism* ; Synoviocytes/pathology* ; Cytokines/metabolism* ; RNA, Messenger/metabolism* ; Fibroblasts/pathology* ; Cell Proliferation

OBJECTIVE: To explore the effect of lenalidomide on human fibroblast-like synovial cells (HFLS) and the therapeutic efficacy on hemophilic arthropathy in hemophilia A mice model. METHODS: In vitro, to remodel the inflammatory environment of synovial tissue after hemorrhage, ferric citrate and recombinant TNF-α were added into the cell culture medium of HFLS. Cell Counting Kit-8 (CCK-8), Enzyme-linked immunosorbent assay (ELISA), Quantitative Real-time PCR (RT-qPCR) and flow cytometry were employed for detection of the effects of lenalidomide on the proliferation ability, pro-inflammatory cytokines release and apoptosis of HFLS cells. In vivo, hemophilia arthropathy was remodeled in hemophilia A mice by induction of hemarthrosis. A series of doses of lenalidomide (0.1, 0.3 and 1.0 g/kg) was administrated intra-articularly. Tissues of knee joints were collected on the 14th day after administration, and the protective effect of lenalidomide on arthritis in hemophilia A mice were evaluated by RT-qPCR and histological grading. RESULTS: In vitro, compared with the untreated control group, lenalidomide could significantly inhibit the proliferation of HFLS cells (P<0.05), and the effect was the most significant when the concentration was 0.01 μmol/L (P<0.001). Compared with the control group, lenalidomide could significantly inhibit the expression levels of TNF-α, IL-1β, IL-6 and IFN-γ in HFLS cells (P<0.05). The flow cytometry results showed that lenalidomide could enhance the apoptotis of HFLS cells (P<0.05). The results of RT-qPCR showed that lenalidomide could significantly reduce the mRNA expression levels of TNF-α, IL-1β, IL-6,MCP-1 and VEGF in the joint tissues (P<0.05). Histological results showed that compared with the injured group, lenalidomide could significantly reduce the pathological sequela after hemarthrosis induction, e.g. synovial thickening and neo-angiogenesis in the synovium. The protection displayed a dose-response pattern roughly. CONCLUSION In vitro, lenalidomide can inhibit the proliferation of HFLS cells, promote their apoptosis, and inhibit the expression of pro-inflammatory cytokines. In vivo, lenalidomide can significantly decrease the expression of pro-inflammatory cytokines in the joints of mice, and prevent the development of inflammation and neo-angiogenesis. The results provide a theoretical and experimental basis for the clinical application of lenalidomide in the treatment of hemophilic arthropathy.
Animals ; Arthritis ; Cytokines/metabolism* ; Hemarthrosis/pathology* ; Hemophilia A/genetics* ; Humans ; Interleukin-6 ; Lenalidomide ; Mice ; Neovascularization, Pathologic ; RNA, Messenger ; Sincalide ; Tumor Necrosis Factor-alpha ; Vascular Endothelial Growth Factor A

OBJECTIVE: Rheumatoid arthritis (RA) progression is associated with the balance of T-regulatory (Treg) and T-helper 17 (Th17) cells, while the role of microRNAs (miRs) in regulating Treg/Th17 cell balance has not been clarified. This study aimed to assess whether moxibustion could regulate Treg/Th17 cell balance by modulating the miR-221/suppressor of cytokine signaling 3 (SOCS3) axis in the RA mouse model. METHODS: A mouse model of collagen-induced arthritis (CIA) was established in male DBA/1J mice. Twenty-two days after CIA induction, the mice received daily treatment with moxibustion for 12 times. Pathological scores were assessed according to the levels of synovial hyperplasia. The expression levels of cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IL-17 and IL-10 were analyzed in serum by enzyme-linked immunosorbent assay. The cluster of differentiation 4 (CD4⁺) splenocytes was analyzed by fluorescence-activated cell sorting. The expression levels of RA-related miRs and target genes were subsequently detected, and the target of miR-221 was confirmed by the dual-luciferase reporter assay. RESULTS: It was revealed that moxibustion treatment decreased the pathological scores and downregulated the expression levels of IL-1β, IL-6, TNF-α, IFN-γ and IL-17, while upregulated the expression level of IL-10. The Treg/Th17 cell balance was regulated by moxibustion treatment. The expression level of miR-221 was suppressed by moxibustion treatment. Furthermore, SOCS3 was found as the direct target of miR-221, which mediated the function of moxibustion by regulating the Treg/Th17 cell balance. CONCLUSION Moxibustion therapy regulated the Treg/Th17 cell balance by modulating the miR-221/SOCS3 axis in the RA mouse model.
Animals ; Arthritis, Experimental/therapy* ; Arthritis, Rheumatoid/therapy* ; Cytokines ; Disease Models, Animal ; Interleukin-10 ; Interleukin-17 ; Interleukin-6 ; Male ; Mice ; Mice, Inbred DBA ; MicroRNAs/genetics* ; Moxibustion ; T-Lymphocytes, Regulatory ; Th17 Cells/pathology* ; Tumor Necrosis Factor-alpha

OBJECTIVETo observe the effect of norcantharidin (NCTD) on collagen-induced arthritis (CIA) rats.

METHODSSixty Sprague-Dawley(SD) rats were randomly divided into 6 groups (n=10): normal group, CIA model group(model group), NCTD low-dose group [1.35 mg/(kg•d)], NCTD middle-dose group [2.7 mg/(kg•d)], NCTD high-dose group [5.4 mg/(kg•d)] and methotrexate (MTX) group [1.8 mg/(kg/w)]. Anesthetized rats were sacrificed by luxation of cervical vertebra after 4 weeks of administration. The arthritis scores were evaluated twice a week. The pathological changes in the ankle joints of rats were observed by hematoxylin-eosin (H&E) staining. The serum levels of interleukin (IL) 1β, IL-6, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), IL-17 and transform growth factor (TGF) β were detected by enzyme linked immunosorbent assay (ELISA). The mRNA expression of retinoid-related orphan nuclear receptorγt (RORγt) and forkhead box P3 (Foxp3) in peripheral blood lymphocytes were confirmed by real-time polymerase chain reaction.

RESULTSMTX and high-dose NCTD not only decreased the arthritis scores but also alleviated the pathological changes in CIA rats' ankle joints compared with the model group (P<0.05 or P<0.01). All doses of NCTD significantly inhibited the serum levels of IL-6, IL-17 and TNF-α in CIA rats (P<0.05). Only middle- and high-dose of NCTD prominently decreased serum IL-1β and TGF-β levels of CIA rats (P<0.05). However, NCTD has no effect on vascular endothelial growth factor (VEGF) level in CIA rats. The Foxp3 mRNA expression in all NCTD groups were increased significantly than in the model group (P<0.05). The mRNA expression of RORγt in NCTD high-dose group was decreased apparently in comparison with the model group (P<0.05).

CONCLUSIONSNCTD showed therapeutic effect on CIA rats by inhibition of cytokines and regulation of Th17/Treg cells.

Animals ; Arthritis, Experimental ; blood ; drug therapy ; pathology ; Bridged Bicyclo Compounds, Heterocyclic ; pharmacology ; therapeutic use ; Cytokines ; blood ; Forkhead Transcription Factors ; metabolism ; Joints ; drug effects ; pathology ; Male ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley

Fibroblast-like synoviocytes (FLS) play a pivotal role in Rheumatoid arthritis (RA) pathogenesis through aggressive migration and invasion. Madecassoside (Madec), a triterpenoid saponin present in Centella asiatica herbs, has a potent anti-inflammatory effect. In the present study, Madec exerted an obvious therapeutic effect in reversing the histological lesions in adjuvant-induced arthritis (AIA) rats. To recognize the anti-rheumatoid potentials of Madec, we further investigated whether Madec interfered with FLS invasion and metalloproteinase (MMP) expression. In cultures of primary FLS isolated from the AIA rats, Madec (10 and 30 μmol·L) was proven to considerably inhibit migration and invasion of FLS induced by interleukin 1β (IL-1β), but exhibiting no obvious effect on cell proliferation. Madec repressed IL-1β-triggered FLS invasion by prohibiting the expression of MMP-13. Additionally, Madec suppressed MMP-13 transcription via inhibiting the MMP-13 promoter-binding activity of NF-κB. Our results further showed that Madec down-regulated the translocation and phosphorylation of NF-κB as demonstrated by Western blotting and immunofluorescence assays. In conclusion, our results suggest that Madec exerts anti-RA activity via inhibiting the NF-κB/MMP-13 pathway.
Animals ; Antirheumatic Agents ; chemistry ; pharmacology ; therapeutic use ; Arthritis, Experimental ; chemically induced ; drug therapy ; pathology ; Cell Movement ; drug effects ; Cell Nucleus ; metabolism ; Cells, Cultured ; Gene Expression Regulation, Enzymologic ; drug effects ; Interleukin-1beta ; pharmacology ; Matrix Metalloproteinase 13 ; genetics ; NF-kappa B ; genetics ; metabolism ; Phosphorylation ; drug effects ; Protein Transport ; drug effects ; Rats ; Signal Transduction ; drug effects ; Synoviocytes ; drug effects ; metabolism ; Transcriptional Activation ; drug effects ; Triterpenes ; chemistry ; pharmacology ; therapeutic use

Stickler syndrome is a genetically heterogeneous disorder that affects the ocular, auditory, and musculoskeletal systems. Ocular-only variant of Stickler syndrome type 1 (OSTL1) is characterized by high risk of retinal detachment without systemic involvement and is caused by alternatively spliced exon 2 mutation of COL2A1. We report the cases of two Korean families with OSTL1 carrying likely pathogenic variants of COL2A1. All patients presented with membranous vitreous anomaly, peripheral retinal degeneration, and/or rhegmatogenous retinal detachment, but no systemic manifestations. By genetic analysis, two likely pathogenic non-exon 2 variants, c.2678dupC (p.Ala895Serfs*49) and c.3327+ 1G>C, were identified in COL2A1. Our results demonstrate that COL2A1 defects in OSTL1 are not confined to mutations in exon 2. Together with molecular data, ophthalmologists should consider genetic diagnosis of Stickler syndrome in patients with vitreous anomaly to prevent blindness from retinal detachment. To our knowledge, this is the first report of genetically confirmed OSTL1 in Korea.
Adult ; Arthritis/*genetics/pathology ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; Collagen Type II/*genetics ; Connective Tissue Diseases/*genetics/pathology ; DNA Mutational Analysis ; Exons ; Female ; Hearing Loss, Sensorineural/*genetics/pathology ; Humans ; Male ; Middle Aged ; Republic of Korea ; Retinal Detachment/*genetics/pathology ; Visual Acuity

The object of this review is to help readers to understand meta-analysis of genetic association study. Genetic association studies are a powerful approach to identify susceptibility genes for common diseases. However, the results of these studies are not consistently reproducible. In order to overcome the limitations of individual studies, larger sample sizes or meta-analysis is required. Meta-analysis is a statistical tool for combining results of different studies on the same topic, thus increasing statistical strength and precision. Meta-analysis of genetic association studies combines the results from independent studies, explores the sources of heterogeneity, and identifies subgroups associated with the factor of interest. Meta-analysis of genetic association studies is an effective tool for garnering a greater understanding of complex diseases and potentially provides new insights into gene-disease associations.
Arthritis, Rheumatoid/genetics/pathology ; Databases, Factual ; *Genetic Association Studies ; Genotype ; Humans ; Polymorphism, Single Nucleotide ; Receptors, Immunologic/genetics

Eupatilin is the main active component of DA-9601, an extract from Artemisia. Recently, eupatilin was reported to have anti-inflammatory properties. We investigated the anti-arthritic effect of eupatilin in a murine arthritis model and human rheumatoid synoviocytes. DA-9601 was injected into collagen-induced arthritis (CIA) mice. Arthritis score was regularly evaluated. Mouse monocytes were differentiated into osteoclasts when eupatilin was added simultaneously. Osteoclasts were stained with tartrate-resistant acid phosphatase and then manually counted. Rheumatoid synoviocytes were stimulated with TNF-alpha and then treated with eupatilin, and the levels of IL-6 and IL-1beta mRNA expression in synoviocytes were measured by RT-PCR. Intraperitoneal injection of DA-9601 reduced arthritis scores in CIA mice. TNF-alpha treatment of synoviocytes increased the expression of IL-6 and IL-1beta mRNAs, which was inhibited by eupatilin. Eupatilin decreased the number of osteoclasts in a concentration dependent manner. These findings, showing that eupatilin and DA-9601 inhibited the expression of inflammatory cytokines and the differentiation of osteoclasts, suggest that eupatilin and DA-9601 is a candidate anti-inflammatory agent.
Animals ; Anti-Inflammatory Agents/pharmacology/*therapeutic use ; Arthritis, Experimental/chemically induced/*drug therapy ; Arthritis, Rheumatoid/drug therapy/pathology ; Cell Differentiation/*drug effects ; Cells, Cultured ; Collagen Type II ; Cytokines/biosynthesis ; Disease Models, Animal ; Drugs, Chinese Herbal/therapeutic use ; Female ; Flavonoids/pharmacology/*therapeutic use ; Humans ; Inflammation/drug therapy/immunology ; Interleukin-1beta/genetics/metabolism ; Interleukin-6/genetics/metabolism ; Lymph Nodes/cytology ; Mice ; Mice, Inbred DBA ; Monocytes/cytology ; Osteoclasts/*cytology ; Plant Extracts/pharmacology ; RNA, Messenger/biosynthesis ; Synovial Membrane/cytology ; T-Lymphocytes, Regulatory/cytology/immunology ; Tumor Necrosis Factor-alpha/pharmacology

Rheumatoid arthritis (RA) and osteoarthritis (OA), two common types of arthritis, affect the joints mainly by targeting the synovium and cartilage. Increasing evidence indicates that a significant network connects synovitis and cartilage destruction during the progression of arthritis. We recently demonstrated that hypoxia-inducible factor (HIF)-2alpha causes RA and OA by regulating the expression of catabolic factors in fibroblast-like synoviocytes (FLS) or chondrocytes. To address the reciprocal influences of HIF-2alpha on FLS and chondrocytes, we applied an in vitro co-culture system using a transwell apparatus. When co-cultured with HIF-2alpha-overexpressing chondrocytes, FLS exhibited increased expression of matrix metalloproteinases and inflammatory mediators, similar to the effects induced by tumor-necrosis factor (TNF)-alpha treatment of FLS. Moreover, chondrocytes co-cultured with HIF-2alpha-overexpressing FLS exhibited upregulation of Mmp3 and Mmp13, which is similar to the effects induced by interleukin (IL)-6 treatment of chondrocytes. We confirmed these differential HIF-2alpha-induced effects via distinct secretory mediators using Il6-knockout cells and a TNF-alpha-blocking antibody. The FLS-co-culture-induced gene expression changes in chondrocytes were significantly abrogated by IL-6 deficiency, whereas TNF-alpha neutralization blocked the alterations in gene expression associated with co-culture of FLS with chondrocytes. Our results further suggested that the observed changes might reflect the HIF-2alpha-induced upregulation of specific receptors for TNF-alpha (in FLS) and IL-6 (in chondrocytes). This study broadens our understanding of the possible regulatory mechanisms underlying the crosstalk between the synovium and cartilage in the presence of HIF-2alpha, and may suggest potential new anti-arthritis therapies.
Animals ; Arthritis/genetics/*immunology/pathology ; Arthritis, Rheumatoid/genetics/immunology/pathology ; Basic Helix-Loop-Helix Transcription Factors/genetics/*immunology ; Cells, Cultured ; Chondrocytes/immunology/metabolism/*pathology ; Coculture Techniques ; Fibroblasts/immunology/metabolism/*pathology ; Gene Expression Regulation ; Interleukin-6/genetics/*immunology ; Male ; Mice ; Mice, Inbred C57BL ; Osteoarthritis/genetics/immunology/pathology ; Synovial Membrane/immunology/metabolism/*pathology ; Tumor Necrosis Factor-alpha/genetics/*immunology ; Up-Regulation

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by abnormal proliferation of synoviocytes, leukocyte infiltration, and angiogenesis. The endoplasmic reticulum (ER) is the site of biosynthesis for all secreted and membrane proteins. The accumulation of unfolded proteins in the ER leads to a condition known as ER stress. Failure of the ER's adaptive capacity results in abnormal activation of the unfolded protein response. Recently, we have demonstrated that ER stress-associated gene signatures are highly expressed in RA synovium and synovial cells. Mice with Grp78 haploinsufficiency exhibit the suppression of experimentally induced arthritis, suggesting that the ER chaperone GRP78 is crucial for RA pathogenesis. Moreover, increasing evidence has suggested that GRP78 participates in antibody generation, T cell proliferation, and pro-inflammatory cytokine production, and is therefore one of the potential therapeutic targets for RA. In this review, we discuss the putative, pathophysiological roles of ER stress and GRP78 in RA pathogenesis.
Animals ; Arthritis, Rheumatoid/genetics/*pathology ; Autoantibodies/immunology ; Cell Proliferation ; Cytokines/biosynthesis/immunology ; Endoplasmic Reticulum/immunology/pathology ; Endoplasmic Reticulum Stress/*immunology ; Haploinsufficiency/genetics ; Heat-Shock Proteins/*genetics/*immunology ; Humans ; Lymphocyte Activation ; Mice ; Neovascularization, Pathologic/genetics ; Protein Folding ; Synovial Membrane/cytology ; T-Lymphocytes/immunology ; Unfolded Protein Response/*immunology