Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0003873 (rheumatoid arthritis)
 53,068 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Granulocyte-macrophage CSF (GM-CSF) is a potent stimulator of macrophages and neutrophils and is produced by rheumatoid arthritis (RA) synovium. We now report studies that identify some of the synovial cells and cytokines responsible for local GM-CSF production and gene expression in RA. GM-CSF was assayed by ELISA in supernatants from cultured RA fibroblast-like synoviocytes stimulated with various cytokines (IL-1 beta, TNF-alpha, macrophage-CSF, IFN-gamma, IL-6, and TGF-beta). Immunoreactive GM-CSF was detected in IL-1 beta and TNF-alpha-stimulated cultures, but not in cells cultured in medium or stimulated with any of the other cytokines. IL-1 and TNF-alpha had a synergistic effect on GM-CSF production. GM-CSF gene expression by fibroblast-like synoviocytes was analyzed by ribonuclease protection assay, Northern blot analysis, and in situ hybridization. Both IL-1 beta and TNF-alpha induced GM-CSF mRNA accumulation, with a maximum effect after 4 h of stimulation. We then studied GM-CSF production by macrophage-like synoviocytes (MLS) isolated from fresh synovial specimens by flow microfluorimetry. Fresh MLS spontaneously secreted the cytokine and exogenous IL-1 beta or TNF-alpha had no effect. After 1 wk in culture, additional stimulation with IL-1 beta or TNF-alpha was required for GM-CSF production. Finally, in situ hybridization performed on freshly isolated subpopulations of synovial cells, identified GM-CSF RNA transcripts in MLS.
 ...
PMID:Cytokines in chronic inflammatory arthritis. VI. Analysis of the synovial cells involved in granulocyte-macrophage colony-stimulating factor production and gene expression in rheumatoid arthritis and its regulation by IL-1 and tumor necrosis factor-alpha. 202 69

Serum triglyceride levels are significantly higher and serum high-density lipoprotein cholesterol levels are lower in patients with gout compared with healthy individuals. Whereas increased serum triglyceride levels exist intrinsically in gout, serum uric acid concentration correlates inversely with insulin sensitivity and positively with serum triglycerides. Interaction of monosodium urate crystals with granulocyte-macrophage colony-stimulating factor and with tumor necrosis factor-activated neutrophils favored the production of interleukin-1 over that of interleukin-1-Ra, resulting in a proinflammatory imbalance. Interaction of the crystals with iron or tyrosine kinase may modify their inflammatory response and can be an important modulating mechanism in gouty arthritis. E-selectin is a specific marker for synovial fluid soluble endothelial activity and is increased in the synovial fluid of patients with gouty arthritis, as well as in that of patients with other inflammatory arthritides. Similarly, E-selectin was found to be high in joints with monosodium urate crystal-induced synovitis. In addition, synovial fluid levels of interleukin-8 were found to be high in gout, rheumatoid arthritis, and osteoarthritis.
 ...
PMID:Gout, uric acid metabolism, and crystal-induced inflammation. 754 16

Rheumatoid synovitis is characterized by an infiltration of mononuclear cells and by the proliferation of synoviocytes. Monocytes and synoviocytes are major producers of cytokines, growth factors, and enzymes that contribute to the rheumatoid arthritis (RA) process. Since they are in close contact in vivo, we engaged in an in vitro study of the functional consequences of their interactions. Coculture of unstimulated elutriated normal blood monocytes over RA synoviocytes resulted in a synergistic increase of the production of IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), leukemia inhibitory factor (LIF), and IL-8, when compared with their respective production in culture alone. In contrast, cytokines such as IL-10, IL-1 beta, IL-1 alpha, and TNF-alpha could not be detected. The IL-6 production in coculture was further increased by the addition of IL-1 beta, GM-CSF, IFN-gamma, or TNF-alpha, but was inhibited by the addition of IL-10, IL-4, IL-13, or IL-1Ra, an effect reverted by the addition of IL-1 beta. Moreover, an inhibition was also observed with anti-CD14 mAb and newly raised mAbs directed against RA synoviocytes. Under reducing conditions, the mAb SY12 precipitated a 150-kDa surface membrane protein, identified as amino-peptidase N (CD13/AP-N). Collectively, these results indicate that 1) monocytes and synoviocytes interact with each other to produce proinflammatory cytokines, 2) pro- and antiinflammatory cytokines have opposite effects on IL-6 production, and 3) molecules such as IL-1, CD14, and CD13 are involved.
 ...
PMID:Contribution of IL-1, CD14, and CD13 in the increased IL-6 production induced by in vitro monocyte-synoviocyte interactions. 756 Oct 64

Immunization of BALB/c mice with human cartilage proteoglycan (aggrecan) produces a progressive polyarthritis, similar in many aspects to human rheumatoid arthritis, and autoreactive T cells are necessary for initiation of the disease. To study the immunopathological mechanisms operating in the synovium of arthritic mice, we isolated a proteoglycan (PG)-specific arthritogenic T-cell hybridoma, 5/4E8, and examined the presentation of PG to this T-cell hybridoma by mouse synovial cells and chondrocytes. Both cell types expressed very low levels of major histocompatibility complex (MHC) class II following isolation and culture and were unable to present PG to the hybridoma. However, following stimulation with interferon-gamma (IFN-gamma), both synovial cells and chondrocytes showed a marked increase in MHC class II expression and consequently were able to present PG very effectively. The PG-specific responses of the hybridoma were abrogated by an anti-Ia monoclonal antibody. Granulocyte-macrophage colony-stimulating factor (GM-CSF), one of the most abundant cytokines in the rheumatoid synovium, had no effect on the antigen-presenting capacity of synovial cells and chondrocytes, either on its own or together with IFN gamma.
 ...
PMID:Interferon-gamma but not granulocyte/macrophage colony-stimulating factor augments proteoglycan presentation by synovial cells and chondrocytes to an autopathogenic T cell hybridoma. 762 93

The effects of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) on DNA synthesis of rabbit synovial cells were studied. IL-1 beta 1000-10,000 U.ml-1, IL-6 10-1000 U.ml-1, TNF alpha 0.5-50 U.ml-1 and GM-CSF 1-100 ng.ml-1 concentration-dependently stimulated DNA synthesis in rabbit synovial cells in culture. Leflunomide (LFM) and its metabolite A77 1726 elicited an inhibitory effect on such cytokine-induced DNA synthesis of synovial cells. These results suggested that IL-1 beta, IL-6, TNF alpha and GM-CSF play a key role in the pathogenesis of rheumatoid arthritis. Inhibition of cytokine-induced proliferation of synovial cells by LFM may partially explain its antirheumatic activity.
 ...
PMID:Leflunomide inhibits cytokine-induced DNA synthesis of rabbit synovial cells in culture. 797 75

Bloodstream neutrophils do not express mRNA for interleukin-1 beta (IL-1 beta), but transcripts for this cytokine are rapidly induced following exposure to recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) in vitro. Levels of IL-1 beta mRNA reach maximal values 1 h after exposure to rGM-CSF and then decline to near basal levels by 4 h. Similarly, rGM-CSF treatment of blood neutrophils in vitro induced increases in levels of mRNA for IL-6 and tumour necrosis factor-alpha (TNF-alpha). RNA extracted from neutrophils isolated from the synovial fluid of patients with rheumatoid arthritis expressed low, but significant levels of IL-1 beta mRNA that were between 0.5 and 3% of the levels that could be maximally induced by rGM-CSF treatment of blood neutrophils. However, transcripts for TNF-alpha and IL-6 were not detected in these synovial fluid neutrophils. mRNA for transforming growth factor-beta (TGF-beta) was constitutively expressed in blood and synovial fluid neutrophils and transcripts for this cytokine were not altered by rGM-CSF exposure. Because of the transient nature of IL-1 beta expression by activated neutrophils, we propose that the low levels of expression of mRNA for this cytokine in the synovial fluid neutrophils represents expression by a small, perhaps newly-recruited and activated, sub-population of cells. IL-1 beta expression by this sub-population may thus contribute to the pathogenesis of rheumatoid disease.
 ...
PMID:Cytokine expression by inflammatory neutrophils. 800 60

Macrophage-like synoviocytes originate in the bone marrow, like other mononuclear phagocytes, and are constantly replaced via the circulation. In rheumatoid synovium sections, 80-100% of the synovial lining cells are macrophage-like cells functioning as antigen processing- and antigen-presenting cells to T lymphocytes. Monocyte and lymphocyte traffic into the rheumatoid arthritis (RA) synovium is mediated by adhesion molecules such as endothelial-leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecules-1 and -2 (ICAM-1 and ICAM-2), as well as monocyte chemotactic protein 1 (MCP-1) and beta 2 integrins (CD11 a,b,c/CD18). Macrophage-like cells in the RA synovium are highly activated based on their morphology, surface class II HLA antigen expression, and synthesis of cytokines such as interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage CSF, and transforming growth-factor beta (TGF-beta). Evidence for type 1 (higher affinity) and type 2 (lower affinity) androgen (ARs) and estrogen receptors (ERs) on macrophage-like synoviocytes in either male or female synovial samples from both RA patients and controls has been reported. In particular, ERs have also been found on CD8+CD29+ CD45R0+ T lymphocytes (memory), infiltrating rheumatoid synovial tissues. Sex hormones have been found to influence macrophage activity in experimental and clinical conditions such as RA. Generally estrogens have immunostimulatory effects, whereas androgens are immuno-suppressive.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Macrophages, synovial tissue and rheumatoid arthritis. 839 94

A large body of clinical experience on the adverse consequences of cytokine administration has accumulated since the last decade. Side-effects reported after the therapeutic use of cytokines has provided evidence that activation of the immune response may sometimes have deleterious consequences. Several effects appeared as a direct consequence of the immune activation induced by cytokines, e.g. flu-like reactions, vascular leak syndrome. Cytokine-induced exacerbation of underlying diseases or immune dysregulation were other complications of growing concern. Interferon-alpha (IFN-alpha) treatment has now been clearly linked with the exacerbation or the occurrence of several types of autoantibodies or autoimmune diseases (thyroiditis, systemic lupus erythematosus, hematologic disorders, insulin-dependent diabetes mellitus) or diseases involving altered cell-mediated immune functions (inflammatory dermatologic diseases, nephritis, pneumonitis, colitis). By contrast immunological side-effects of IFN-beta and IFN-gamma have been seldom reported. However, the extent of clinical experience with both of these cytokines is still very limited. Interleukin-2 (IL-2) has also been implicated in various conditions that may involve immunopathological processes (thyroid disorders, rheumatoid arthritis, dermatological diseases, interstitial nephritis). Growth factors have been more specifically linked with the development or the exacerbation of dermatological inflammatory diseases through neutrophils, monocytes/macrophages or eosinophils activation (e.g. cutaneous vasculitis and generalized cutaneous eruption, Sweet's syndrome, bullous eruption, psoriasis). Exacerbation of autoimmune thyroiditis was described with granulocyte-macrophage colony-stimulating factor (GM-CSF) only. The immunogenicity of cytokines is also of great relevance and the occurrence of antibodies binding IFN-alpha and IFN-beta, IL2 and GM-CSF have been reported. While the clinical significance of non-neutralizing antibodies is not clearly established, an absence of response or reversal of clinical efficacy has been described in patients developing neutralizing antibodies. Finally, several isolated reports have recently suggested that IFN-alpha treatment may be associated with several immunosuppressive effects while IL-2 is clinically associated with an increased incidence of infectious complications.
 ...
PMID:Immune-mediated side-effects of cytokines in humans. 863 83

This study was undertaken to investigate the immunomodulatory effect of clarithromycin against synovial fibroblast-like cells (synoviocytes). Synovial tissue obtained from rheumatoid arthritis (RA) or osteoarthritis (OA) patients was enzymatically digested to separate synoviocytes. The synoviocytes were cultured with or without cytokines in the presence of various concentrations of clarithromycin. The expression of costimulatory molecules was examined on the surface of the synoviocytes, using specific MoAbs and flow cytometry. The production of cytokines by synoviocytes was also measured using an immunoenzymatic assay. Finally, autologous T cells were stimulated by interferon-gamma (IFN-gamma)-treated synoviocytes in response to purified protein derivative (PPD). In some experiments, MoAbs specific for costimulatory molecules or clarithromycin were added and 3H-thymidine incorporation was counted. Intercellular adhesion molecule-1 (ICAM-1), LFA-3 and vascular cell adhesion molecule-1 (VCAM-1) were detected on the surface of both RA and OA synoviocytes. However, ICAM-2, B7-1 and B7-2 were not detected, and cytokines failed to induce these molecules. Both spontaneous and up-regulated expression of ICAM-1, LFA-3 and VCAM-1 by IFN-gamma, IL-1beta or 12-o-tetradecanoyl phorbol 13-acetate (TPA) were markedly suppressed by clarithromycin in a dose-dependent manner at concentrations between 0.1 and 10 microg/ml. The production of IL-1beta, IL-6, IL-8, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) but not IL-1alpha and tumour necrosis factor-alpha (TNF-alpha) by synoviocytes was detected. Clarithromycin significantly suppressed the production of these cytokines, but did not enhance IL-10 production. Finally, autologous T cells were stimulated by IFN-gamma-treated synoviocytes in response to PPD. As clarithromycin suppressed HLA-DR and costimulatory molecule expression was enhanced by IFN-gamma, autologous T cell proliferation was markedly inhibited by clarithromycin. Clarithromycin has a considerable immunosuppressive effect on synoviocytes by inhibiting costimulatory molecule expression, cytokine production and antigen-specific T cell proliferation induced by synoviocytes.
 ...
PMID:Inhibitory effect of clarithromycin on costimulatory molecule expression and cytokine production by synovial fibroblast-like cells. 909 36

Interleukin 1-beta (IL-1 beta), IL-2, IL-4, IL-5, IL-6, IL-8, tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-beta (TGF-beta) and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression was determined in knee synovium of 16 patients with rheumatoid arthritis (RA) and 16 patients with seronegative spondyloarthropathies (SSP), by using polymerase chain reaction (PCR) amplification. The pattern of cytokines observed in RA synovium is of the macrophage-fibroblast type, with the highest expression of IL-1 beta and TGF-beta. GM-CSF and IL-2 bands were visualized in a minority of patients. Neither IL-4 nor IL-5 could be detected. No significant differences were observed in the cytokine profile between patients with early (< 12 months) and more advanced disease. No differences were observed according to gender, age, rheumatoid factor status and the duration of knee synovitis. The pattern of cytokines in the synovium of SSP patients is similar to that observed in RA patients and does not change in relation to disease duration. IL-2 was the only T-cell cytokine observed. These data provide evidence that the macrophage-fibroblast cells have an important role in early and more advanced rheumatoid synovitis, and show that this is also true for SSP peripheral synovitis.
 ...
PMID:Comparative cytokine gene expression in synovial tissue of early rheumatoid arthritis and seronegative spondyloarthropathies. 911 72


<< Previous 1 2 3 4 5 6 7 8 9 Next >>