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

Aberrant expression of the antioxidant enzyme glutathione peroxidase (GPx) could contribute to the etiology of rheumatoid arthritis (RA). However, previous enzyme activity studies examining this relationship were inconclusive. Indirect evidence for this relationship derives from the known efficacy of gold therapy in RA, since gold compounds specifically inhibit GPx. The hypothesis that variants of GPx are associated with RA was examined by two approaches: enzyme activity analysis and restriction fragment length polymorphism (RFLP) association analysis. No significant difference was found in whole blood GPx activity between 28 RA patients and 36 controls. GPx activity appeared to be independent of sex, race, or type of drug treatment. However, a statistically significant difference was found with respect to treatment responsiveness. RA patients classified as good responders to gold therapy, but who were no longer taking gold, had a significantly higher GPx activity compared to both the controls and good responders currently on gold therapy. Aberrantly high GPx activity could contribute to RA by generating excess oxidized glutathione, a potent collagenase activator. Gold therapy would reduce GPx activity to normal levels. The restriction enzyme Pvu II in conjunction with a GPx gene probe identified a useful RFLP (Al, 22 kbp; A2, 15 kbp) with allelic frequencies of A1 and A2 equal to 0.11 and 0.89, respectively, in the control population. No statistically significant association, however, could be demonstrated between this allelic variant of the GPx gene and RA.
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PMID:Role of glutathione peroxidase in rheumatoid arthritis: analysis of enzyme activity and DNA polymorphism. 134 42

Typical erosions of articular joint structures in rheumatoid arthritis and in the spontaneous destructive hind-limb arthropathy of autoimmune MRL-lpr/lpr (MRL/l) mice occur predominantly in areas contiguous with proliferating synovial lining cells, suggesting release of proteolytic enzymes from these cells. Synovial lining cells were isolated from arthritic MRL/l mice, and the spontaneous expression of the interstitial procollagenase and its potential transcriptional factors, egr-1 and c-fos, was examined in vitro. The data indicate that basal collagenase RNA expression was stronger in MRL/l cells than in virus-transformed cells. Moreover, elevated RNA levels of the c-fos gene could be detected in the collagenase-expressing synovial lining cells in vitro. In a related immunohistochemical study, collagenase was detected in situ in proliferating synovial lining cells as well as in chondrocytes of the first stage of pathological changes in the MRL/l mouse arthropathy.
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PMID:Expression of collagenase and potential transcriptional factors in the MRL/l mouse arthropathy. 137 11

Interleukin-1 (IL-1) has protean effects in the pathogenesis of rheumatoid arthritis (RA). These effects include production of prostaglandins and collagenase from rheumatoid fibroblasts as well as upregulation of adhesion molecule expression on these cells. IL-1 can activate monocytes and neutrophils, as well as promote the growth of fibroblasts and endothelial cells. Recently, a novel interleukin-1 receptor antagonist protein (IRAP) has been isolated, purified, cloned, and expressed, which may modulate the effects of IL-1. In this study, we present data demonstrating that macrophages isolated from human RA synovial tissues express both IL-1 and IRAP genes. In addition, RA synovial tissue macrophages and lining cells display IL-1 and IRAP antigenic expression by immunohistochemistry. In contrast, osteoarthritis synovial tissues, as compared to RA, have fewer IL-1 and IRAP-positive macrophages. Thus, the production of IL-1 balanced by IRAP may affect the joint destruction found in these diseases.
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PMID:Expression of interleukin-1 and interleukin-1 receptor antagonist by human rheumatoid synovial tissue macrophages. 139 21

In view of the important role of interstitial collagenase in the pathogenesis of rheumatoid arthritis (RA), we studied the expression of fibroblast-type collagenase in rheumatoid synovium and searched for its potential transcription factors, namely the oncoprotein c-fos and the early-growth-response gene-1 (egr-1), an inducible zinc-finger encoding gene. Elevated levels of RNA sequences complimentary to c-fos and egr-1 cDNA probes could be detected in cytoplasmic extracts of collagenase-expressing synovial fibroblast-like cells when compared to equivalent RNA amounts isolated from control fibroblasts. Utilizing immunocytochemistry, immunoreactivity for c-fos oncoprotein was found in 13 of 19 joint specimens obtained from patients with active RA. These oncoprotein data were positively correlated to the collagenase expression in the same specimens. Moreover, immunohistochemical analysis confirmed the localization of both oncoprotein c-fos and fibroblast-type collagenase within synovial fibroblast-like cells attached to bone erosions.
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PMID:Spontaneous expression of immediately-early response genes c-fos and egr-1 in collagenase-producing rheumatoid synovial fibroblasts. 141 Oct 83

The effects of various reactive oxygen species on latent human neutrophil and fibroblast-type interstitial collagenases were studied. Latent human neutrophil collagenases (proMMP-8) was efficiently activated by hypochlorous acid and hydrogen peroxide and less efficiently by the serine proteinases trypsin and chymotrypsin. Human plasmin and plasma kallikrein did not activate latent human neutrophil collagenase. The activation of latent human neutrophil collagenase by hypochlorous acid and hydrogen peroxide corresponded to the activation obtained with the other known non-proteolytic activators phenylmercuric chloride and gold thioglucose. The activation by hydrogen peroxide was inhibited by mannitol and desferoxamine, suggesting a localized Fenton-type reaction to be responsible for the generation of hydroxyl radical and/or hydroxyl radical-like reactive oxygen pathway of neutrophil procollagenase does not involve plasmin and plasma kallikrein, which are efficient proteolytic activators of latent fibroblast-type procollagenase (proMMP-1). Fibroblast procollagenase was also slightly activated by hypochlorous acid and gold thioglucose. Thus neutrophil procollagenase seems to prefer non-proteolytic means of activation and reactive oxygen species can be regarded as potent activators in vivo. Synovial-fluid neutrophils from rheumatoid arthritis patients were found to release collagenase in 30% active form when compared to same patients' peripheral blood neutrophils, which released collagenase in completely latent form. This may indicate that the triggering of neutrophil at the site of inflammation in vivo involves initial oxidative activation of collagenase upon the degranulation process.
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PMID:Reactive oxygen species as regulators of human neutrophil and fibroblast interstitial collagenases. 144 75

Interleukin 1 receptor antagonist (IL-1ra) has been found in glycosylated form in the urine of febrile patients or of children with rheumatoid arthritis, and in the supernatant of monocytes cultured in the presence of immune complexes. It blocks competitively the binding of IL-1 alpha and beta to their receptors. Produced amongst others by mononuclear cell lines and matured monocytes and alveolar macrophages, it prevents prostaglandin E2 and collagenase production by fibroblasts and synovial cells. In mice, IL-1ra improves survival after lethal endotoxemia. In this study, both natural and recombinant human IL-1ra (rhIL-1ra) were tested in an allogeneic T-cell reaction, and in mitogen- or antigen-induced lymphocyte proliferation. Neither the natural nor the rhIL-1ra blocked T-cell proliferation, but rhIL-1ra abolished the effect of exogenous IL-1 beta. This was not due to a loss of bioactivity of IL-1ra in culture, as the IL-1ra of the supernatant still completely inhibited 125I-IL-1 alpha binding to EL 4-6.1 cells and markedly reduced PGE2 production during antigen presentation. We conclude that IL-1ra alone, even at high concentrations, is not sufficient to block human T-cell proliferation in vitro.
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PMID:Natural and recombinant interleukin 1 receptor antagonist does not inhibit human T-cell proliferation induced by mitogens, soluble antigens or allogeneic determinants. 153 18

In vitro, rheumatoid arthritis (RA) synovial cells display several of the characteristics of neoplastic and virally transformed cells. The recent observation that synovial cell cultures, derived from collagenase digests of synovial membranes from RA patients, proliferate in serum-free medium suggests that these cells have the capacity to synthesize those factors essential for their growth. Direct immunocytochemical staining and Western analysis have identified transforming growth factor-beta (TGF-beta) band and basic fibroblast growth factor (FGF) in the cytoplasm of RA and normal synovial cells in long-term culture. Greater amounts of each growth factor were found in RA, as compared with normal synovial cell lysates. Western analysis identified a single TGF-beta band in RA and normal synovial cell lysates. Four bands were identified by Western analysis on RA synovial cell lysates probed with monoclonal antibodies recognizing bFGF, whereas only two bands (which co-migrated with human native recombinant bFGF) were identified in normal cell lysates probed with these antibodies. Gene expression analysis using PCR identified mRNA transcripts encoding TGF-beta 1 and FGF-2 (bFGF), but not TGF-beta 2 in all cell cultures studied. Taken together, these data indicate that cultured synovial cells co-express TGF-beta 1 and multiple isoforms of hFGF. These data further strengthen the concept that both polypeptide growth factors are involved in the regulation of synovial cell growth.
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PMID:Regulation of synovial cell growth by polypeptide growth factors. 156 59

The extracellular matrix (ECM) of articular cartilage is subject to a steady remodelling process. The collagenous components of the ECM are characterized by a very low rate of metabolism, whereas the proteoglycans exhibit an active turnover. The main proteolytic enzymes degrading the ECM components are collagenase, gelatinase and stromelysin. These enzymes undergo under pathological circumstances a remarkable enhancement of synthesis and activity. Although each of these enzymes appears to degrade one ECM component specifically, there is evidence for synergistic effects of most of them. Gelatinase acts synergistically with collagenase in degrading insoluble interstitial collagens and stromelysin activates collagenase. Thus a cascade mechanism may exist in which the cartilage-ECM is completely degraded. Yet, it is not crucial which part of the ECM (collagens or proteoglycans) is primarily degraded. The integrity of the ECM rather depends on the balance between anabolic and catabolic processes, the upset of which results in damage of the articular cartilage. Cartilage destruction in rheumatoid arthritis and osteoarthritis is considered to be a result of this imbalance in favour of the catabolic processes. This would lead to a decrease in proteoglycans which causes fibronectin deposition in the cartilage ECM. Due to chemotaxic effects of fibronectin on fibroblasts, the enrichment of this glycoprotein in the ECM gives rise to cartilage fibrosis and early degeneration.
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PMID:[Proteolytic enzymes and the destruction of articular cartilage in arthritis and chronic polyarthritis]. 164 88

Tetracyclines have long been considered useful adjuncts in peridontal therapy based on their antimicrobial efficacy against putative periodontopathogens. However, recently these drugs were found to inhibit mammalian collagenases and several other matrix metalloproteinases (MMPs) by a mechanism independent of their antimicrobial activity. Evidence is presented that this property may be therapeutically useful in retarding pathologic connective tissue breakdown, including bone resorption. The experiments leading to this discovery are described and possible mechanisms are addressed, including the specificity of tetracyclines' anti-collagenase activity, the role of the drugs' metal ion (Zn2+, Ca2+)-binding capacity, and the site on the tetracycline molecule responsible for this nonantimicrobial property. Of extreme interest, the tetracycline molecule has been chemically modified in multiple ways, generating a new family of compounds called CMTs (chemically modified tetracyclines) that lack antimicrobial but still retain anti-collagenase activity. The first of these CMTs, 4-de-di-methylaminotetracycline, was found not to produce a major side-effect of antimicrobial tetracycline therapy--its administration to experimental animals did not result in the emergence of tetracycline-resistant microorganisms in the oral flora and gut. Numerous examples of the clinical potential of this non-antimicrobial property of tetracyclines in the treatment of periodontal and several medical diseases (e.g., sterile corneal ulcers, rheumatoid arthritis, skin bullous lesions, tumor-induced angiogenesis and metastasis) are discussed.
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PMID:Tetracyclines inhibit connective tissue breakdown: new therapeutic implications for an old family of drugs. 165 39

Degradation of cartilage in rheumatoid arthritis (RA) may be in part due to release of collagenase from specific granules of polymorphonuclear neutrophil leukocytes (PMNs) during degranulation. We decided to study, not synovial fluid (SF) collagenase, but PMN collagenase reserves. PMN were isolated from parallel SF and peripheral blood (PB) samples obtained from 7-arthritis patients. PMNs were stimulated in vitro by tetradecanoyl-phorbol-13-acetate (TPA). Collagenase activity in the supernatant without and with phenylmercuric chloride activation was studied. Compared to PB PMNs, there was no consistent decrease in the total collagenase reserves in the inflammatory SF PMNs. This suggests that the release of collagenase in the inflammatory synovial fluid does not deplete SF PMNs of the collagenase synthesized at the myelocyte stage. The role of PMN collagenase in pathogenesis of cartilage destruction would then seem to be more dependent on local release and autoactivation at cartilage surface by adherent PMNs and not excessive collagenase release from free floating SF PMNs at single cell level. Furthermore, under the experimental conditions used the proportion of collagenase released in active form was higher in SF PMN specimens than in PB PMN specimens (p less than 0.01). The predominant collagenous component of adult cartilage, native type II collagen, was degraded by PMN collagenase as fast as native type I collagen. These findings suggest an important role for this enzyme in destruction of the free cartilage surface in RA.
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PMID:Collagenase reserves in polymorphonuclear neutrophil leukocytes from synovial fluid and peripheral blood of patients with rheumatoid arthritis. 165 76


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