Interleukin (IL)-36 is a family of cytokines that belongs to the larger IL-1 superfamily. IL-36 agonist/antagonist binds to the interleukin-36 receptor involving in physiological inflammation regulation and pathogenesis of many inflammatory diseases. In inflammatory joint diseases, the expression of IL-36 changes, and some studies have initially explored the role of IL-36 in these diseases. In psoriatic arthritis, IL-36 signal mediates plasma cell and fibroblast-like synoviocyte crosstalk presenting IL-36 agonist/antagonist imbalance. In rheumatoid arthritis, IL-36 agonists induce fibroblast-like synoviocyte to produce pro-inflammatory factors, while IL-36 antagonist deficiency leads to lesion progression. In osteoarthritis, IL-36 agonists induce chondrocytes to produce catabolic enzymes and pro-inflammatory factors. This article reviews the expression and function of IL-36 in different inflammatory joint diseases to provide a reference for revealing their pathogenic mechanisms and discovering therapeutic targets.
Humans ; Interleukins ; Arthritis, Rheumatoid ; Osteoarthritis/pathology* ; Arthritis, Psoriatic/metabolism* ; Cytokines

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

Accumulating evidences have documented that angiogenesis is closely linked to inflammation and regulators of angiogenesis play key roles in various inflammatory conditions. PlGF is an angiogenic protein belonging to the VEGF family and is upregulated mainly in pathologic conditions. Recently, PlGF was discovered having a proinflammatory role in inflammatory arthritis and its serum level drew attention not only as a useful surrogate biomarker but also a potential therapeutic target in atherosclerosis and various cancers. Particularly, PlGF has attractive clinical values because endogenous PlGF is redundant for vascular development and physiological vessel maintenance in healthy adults. However, there have been conflicting results about the efficacy of PlGF inhibition depending on the experimental and clinical settings. Further close investigations for resolving the puzzle of PlGF biology are required.
Animals ; Arthritis, Rheumatoid/*metabolism/pathology ; Atherosclerosis/*metabolism/pathology ; Biological Markers/metabolism ; Humans ; Inflammation/metabolism ; Neoplasms/*metabolism/pathology ; Neovascularization, Pathologic ; Pregnancy Proteins/*metabolism ; Signal Transduction

S100A8 and S100A9 are major leukocyte proteins, known as damage-associated molecular patterns, found at high concentrations in the synovial fluid of patients with rheumatoid arthritis (RA). A heterodimeric complex of S100A8/A9 is secreted by activated leukocytes and binds to Toll-like receptor 4, which mediates downstream signaling and promotes inflammation and autoimmunity. Serum and synovial fluid levels of S100A8/A9 are markedly higher in patients with RA than in patients with osteoarthritis or miscellaneous inflammatory arthritis. Serum levels of S100A8/A9 are significantly correlated with clinical and laboratory markers of inflammation, such as C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor, and the Disease Activity Score for 28 joints. Significant correlations have also been found between S100A8/A9 and radiographic and clinical assessments of joint damage, such as hand radiographs and the Rheumatoid Arthritis Articular Damage score. In addition, among known inflammatory markers, S100A8/A9 has the strongest correlation with total sum scores of ultrasonography assessment. Furthermore, baseline levels of S100A8/A9 are independently associated with progression of joint destruction in longitudinal studies and are responsive to change during conventional and biologic treatments. These findings suggest S100A8/A9 to be a valuable diagnostic and prognostic biomarker for RA.
Arthritis, Rheumatoid/*blood/pathology/radiography ; Arthrography ; Biological Markers/blood ; Calgranulin A/*blood ; Calgranulin B/*blood ; Humans ; Joints/pathology ; Synovial Fluid/metabolism

OBJECTIVETo investigate a method for quantitative differential diagnosis of damp-heat and cold-damp impeding syndrome of rheumatoid arthritis (RA) in Chinese medicine (CM).

METHODSLaboratory parameters were collected from 306 patients with RA. The clinical symptoms and laboratory parameters were compared between patients with these two syndromes (158 with RA of damp-heat impeding syndrome, and 148 with RA of cold-damp impeding syndrome), and a regression equation was established to facilitate discrimination of the two RA syndromes.

RESULTSThere were significant differences in disease activity score in 28 joints [DAS28 (4)], erythrocyte sedimentation rate (ESR), white blood cell count (WBC), C-reactive protein (CRP), platelet count (PLT), albumin (ALB) and globulin (GLB) between the two syndrome of RA (P<0.05). Logistic regression analysis showed that the parameters ESR, WBC, CRP, joint pyrexia, joint cold, thirst, sweating, aversion to wind and cold, and cold extremities were statistically useful to discriminate damp-heat from cold-damp impeding syndrome. The regression equation was as follows: P=1/{1+exp[-(3.0-0.021X (1)-0.196X (2)-0.163X (3)-1.559X (4)+1.504X (5)-0.927X (6)-1.039X (7)+1.070X (8)+1.330X (9))]}. The independent variables X (1)-X (9) were ESR, WBC, CRP, hot joint, cold joint, thirst, sweating, aversion to wind and cold, and cold limbs. A P value > 0.5 signified cold-damp impeding syndrome, and a P value < 0.5 signified damp-heat impeding syndrome. The accuracy was 90.2%.

CONCLUSIONThe regression equation may be useful for discriminating damp-heat from cold-damp impeding syndrome of RA.

Arthritis, Rheumatoid ; pathology ; therapy ; Cytokines ; metabolism ; Demography ; Female ; Hot Temperature ; Humans ; Logistic Models ; Male ; Medicine, Chinese Traditional ; Middle Aged ; Syndrome

OBJECTIVE: To investigate the therapeutic mechanism of emodin in the treatment of rheumatoid arthritis (RA) using a network pharmacology-based method and validate this mechanism in a fibroblast-like synovial cell line. METHODS: The PubChem, Targetnet, SwissTargetPrediction, Genecards, OMIM, and DisGeNET databases were searched to obtain emodin targets and RA-related genes. A protein-protein interaction (PPI) network was constructed, and GO and KEGG pathway enrichment analyses were carried out to analyze the intersection genes. AutoDock4.2.6 software was used to simulate molecular docking between emodin and its candidate targets. In a cultured fibroblast-like synovial cell line (MH7A), the effects of different concentrations of emodin on proliferation of tumor necrosis factor-α (TNF-α)-induced cells were investigated using CCK-8 assay, cell scratch experiment and flow cytometry; the changes in the expressions of nuclear factor-κB (NF-κB) pathway proteins were detected using Western blotting, and the mRNA expressions of the hub genes were examined with RT-qPCR. RESULTS: We identified 32 intersection genes of emodin and RA, and the key targets including CAPS3, ESR1, and MAPK14 involved mainly the NF-κB signaling pathway. Cell scratch experiment and flow cytometry demonstrated a strong inhibitory effect of emodin on MH7A cell proliferation. Treatment with TNF-α significantly increased the cellular expressions of the NF-κB pathway proteins, which were obviously lowered by treatment with 80 μmol/L emodin. The results of RT-qPCR showed that TNF-α treatment obviously up-regulated the expressions of the hub genes COX2 and P38MAPK, and emodin treatment significantly down-regulated the expressions of MAPK and PTGS2 and up-regulated the expression of CASP3. CONCLUSION The therapeutic effect of emodin on RA is mediated mainly through regulation of cell proliferation, apoptosis, and the NF-κB pathway.
Arthritis, Rheumatoid/pathology* ; Emodin/pharmacology* ; Humans ; Molecular Docking Simulation ; NF-kappa B/metabolism* ; Network Pharmacology ; Tumor Necrosis Factor-alpha/pharmacology*

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. It is known that aucubin (AU) exerts anti-inflammatory activity, but its effects and mechanisms in RA are unclear. This study investigated the anti-inflammatory effects and mechanisms of AU in vivo and in vitro. Human fibroblast-like synoviocyte cells from patients with RA (HFLS-RA), RAW264.7 cells, and MC3T3-E1 cells were used to evaluate the effects of AU on migration, invasion, apoptosis, osteoclast differentiation and production. Immunofluorescence was used to observe nuclear translocation of nuclear factor (NF)-κB, the double luciferase reporter gene method was used to observe NF-κB-p65 activity in AU-treated MC3T3-E1 cells. RT-qPCR was used to measure expression of bone metabolism and inflammation-related genes, and western blot was used to measure bone metabolism and NF-κB protein expression levels. Collagen-induced arthritis (CIA) rat model was used for pharmacodynamics study. Arthritis indexes were measured in the ankle and knee, histological staining and Micro-computed tomography were performed on the ankle joints. Also, inflammatory factor gene expression and the levels of NF-κB-related proteins were detected as in vitro. AU effectively inhibited HFLS-RA cell migration and invasion, promoted apoptosis, and inhibited RAW264.7 cell differentiation into osteoclasts, as well as inhibited NF-κB-p65 activity in MC3T3-E1 cells. Notably, AU significantly reduced the gene expression levels of three cell-related inflammatory factors and bone metabolism factors, effectively inhibited the expression of p-Iκκα β, p-IκBα, and p-p65 proteins. In vivo, AU relieved joint inflammation, reduced related inflammatory factors, and inhibited NF-κB signaling. It could be used to treat RA-related synovial inflammation and bone destruction through the NF-κB pathway.
Animals ; Anti-Inflammatory Agents/therapeutic use* ; Arthritis, Experimental ; Arthritis, Rheumatoid/drug therapy* ; Cells, Cultured ; Humans ; Inflammation/pathology* ; Iridoid Glucosides ; NF-kappa B/metabolism* ; Rats ; X-Ray Microtomography

OBJECTIVETo observe the expression of peripheral blood CD4+ T lymphocyte apoptosis gene in rheumatoid arthritis (RA) patients with cold dampness type (CDT), and to explore its correlation with clinical indicators of RA.

METHODSSixteen RA patients with CDT (as the RA group) and 16 healthy subjects (as the normal control group) were recruited. CD4 T cell apoptosis rate was detected in the RA group and the normal control group using FCM. mRNA expressions of fas, fasL, caspase-3, caspase-8, bcl-2, and bax were detected using RT-PCR. Correlations between the expression of apoptosis gene and clinical activity indicators of RA (ESR, CRP, RF, CCP, integrals for Chinese medial symptoms, morning stiffness time, joint tenderness number, joint swelling number, DAS28-3) were analyzed.

RESULTSThe apoptosis rate of CD4+ T was significantly lower in the RA group than in the control group [(2. 6 +/- 0.9) % vs. (7.7 +/- 1.3) %, P < 0.01]. mRNA expression levels of fas, fasL, caspase-8, caspase-3, and bax mRNA of CD4+ T significantly decreased, but bcl-2 mRNA expression increased in the RA group (P < 0.01). The apoptosis rate of CD4+ T was negatively correlated with ESR (P < 0.05). The mRNA expression of caspase-8 was negatively correlated with joint swelling number (P < 0.05). The mRNA expression of bcl-2 was negatively correlated with integrals for Chinese medial-symptoms and joint function classification (P < 0.01, P < 0.05).

CONCLUSIONApoptosis obstacle exists in peripheral blood CD4 +T lymphocyte of RA patients, and is closely related to disease activity.

Apoptosis ; Arthritis, Rheumatoid ; diagnosis ; metabolism ; pathology ; CD4-Positive T-Lymphocytes ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Fas Ligand Protein ; Humans ; RNA, Messenger

OBJECTIVES: To analyze arthritic manifestations in Behcet disease, which is one of the most common manifestations of Behcet disease. METHODS: Among the patients who visited the Rheumatology Division, Keimyung University Dongsan Medical Center, Taegu, Korea from March 1997 to February 1998, 35 patients, with more than 3 months follow-up, were compatible for the diagnosis of Behcet disease according to the Shimizu criteria, after exclusion of uncertain or possible Behcet cases. The presence of various manifestations was evaluated. Regarding the joint manifestations, the involved joint, signs and the pattern of the articular symptoms were examined. Basic laboratory tests, HLA studies and simple radiologic studies were done. RESULTS: All 35 patients had evident, recurrent, painful oral ulcers by the study definition. Genital ulcers were found in 29%, skin lesions in 77%, uveitis in 9%, gastrointestinal ulcerations in 6% and vascular manifestations in 6%. Joint manifestations appeared in 97%. Knee(91%), proximal interphalangeal (53%) and metacarpophalangeal joints(21%) were the main sites. Tenderness was prominent in 91% and swelling in 44%. Polyarticular presentation was found in 47%. In most cases (76.4%), the articular symptom was short-lasting. C-reactive protein was likely to be positive in active Behcet disease. HLA B51 was positive in 46%. CONCLUSIONS: In Behcet disease, various manifestations can be found. The arthritic manifestation seems quite common. It may present as seronegative rheumatoid arthritis. Otherwise, it may present as palindromic rheumatism.
Adult ; Arthritis, Rheumatoid/diagnosis* ; Arthritis, Rheumatoid/blood ; Behcet's Syndrome/diagnosis* ; Behcet's Syndrome/blood ; C-Reactive Protein/metabolism ; Comparative Study ; Diagnosis, Differential ; Female ; Human ; Joints/pathology ; Male ; Middle Age ; Rheumatic Diseases/diagnosis* ; Rheumatic Diseases/blood

The aim of this study was to investigate the expression and localization of cyclooxygenase-1 and -2 (COX-1 and COX-2) in synovial tissues from patients with rheumatoid arthritis (RA). Synovial tissues from 9 patients with RA and 5 patients with osteoarthritis (OA) were examined for COX-1 and COX-2 expressions by immunohistochemical staining using 2 polydonal COX-1 and COX-2 antibodies. In RA synovia, synovial lining cells showed intense immunostaining for COX-1, whereas slight to moderate staining was observed in inflammatory cells, stromal fibroblast-like cells and vascular endothelial cells. There was no significant difference in COX-1 expression between RA and OA synovia. The localization of COX-2 expression dearly differed from that of COX-1 expression, being most intense in inflammatory cells. However, there was no difference in COX-1 and COX-2 expressions between RA and OA synovial tissues. Our observations support that inflammatory mechanisms modulated by COX-1 and COX-2 in chronic RA synovium might be similar to those in chronic OA synovium.
Adult ; Aged ; Arthritis, Rheumatoid/pathology ; Arthritis, Rheumatoid/enzymology* ; Cell Division ; Female ; Fibrin/metabolism ; Human ; Isoenzymes/metabolism ; Isoenzymes/biosynthesis* ; Male ; Middle Age ; Neutrophil Infiltration ; Osteoarthritis/enzymology ; Prostaglandin-Endoperoxide Synthase/metabolism ; Prostaglandin-Endoperoxide Synthase/biosynthesis* ; Stromal Cells/pathology ; Stromal Cells/enzymology ; Synovial Membrane/pathology ; Synovial Membrane/enzymology*