Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Interleukin-1 beta is believed to contribute to the pathophysiology of rheumatoid arthritis by activating collagenase gene expression. We have used a cell culture model of rabbit synovial fibroblasts to examine the molecular mechanisms of IL-1 beta-mediated collagenase gene expression. Stimulation of rabbit synovial fibroblasts with 10 ng/ml recombinant human IL-1 beta resulted in a 20-fold increase in collagenase mRNA by 12 h. Transient transfection studies using collagenase promoter-CAT constructs demonstrated that proximal sequences responded poorly to IL-1 beta, possibly due to insufficient activation of AP-1 by this cytokine. More distal sequences were required for IL-1 beta responsiveness, with a 4700 bp construct showing approximately 5-fold induction above control. To examine post-transcriptional mechanisms, transcript from a human collagenase cDNA was constitutively produced by the simian virus 40 early promoter. IL-1 beta stabilized the constitutively expressed human transcript. Furthermore, mutation of the ATTTA motifs in the 3' untranslated region of the human gene also stabilized the transcript. Finally, the rabbit collagenase 3' untranslated region destabilized a constitutively transcribed chloramphenicol acetyltransferase transcript. These data indicate that in addition to activating transcription, IL-1 beta increases collagenase transcript stability by reversing the destabilizing effects of sequences in the 3' untranslated region.
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PMID:Regulation of collagenase gene expression by IL-1 beta requires transcriptional and post-transcriptional mechanisms. 798 35

Stromelysin-1 (MMP-3) is an important member of the matrix metalloproteinase family. In joint-degrading diseases like arthritis, elevated levels of MMP-3 protein are detected in synovial fluid using immunological methods. However, these methods do not discriminate between active and inactive enzyme. In the present study, a specific stromelysin activity assay was developed using the selective fluorogenic substrate TNO003 (Dabcyl-Gaba-Arg-Pro-Lys-Pro-Val-Glu / Nva-Trp-Arg-Glu-(EDANS)-Ala-Lys-NH2, / =cleavage site). For its use in biological media, cleavage of TNO003 by enzymes other than stromelysin was effectively blocked by a proteinase inhibitor cocktail. Spiking of MMP-3 to synovial fluid resulted in an MMP-3 concentration-dependent linear increase in activity. The measured MMP-3 activity was not affected by the addition of MMP-13, even in a 5-fold excess over MMP-3. Synovial fluid from rheumatoid arthritis patients demonstrated 100-fold higher levels of active stromelysin than control synovial fluids.
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PMID:Highly increased levels of active stromelysin in rheumatoid synovial fluid determined by a selective fluorogenic assay. 942 33

The degradation of fibrillar type II collagen is a major feature of cartilage destruction in rheumatoid arthritis (RA). Since collagenase 3 is produced by chondrocytes and preferentially degrades type II cartilage collagen, it seemed likely that this enzyme would have a prominent role in the destruction of rheumatoid joints. Using immunolocalization techniques, we have examined and compared the production and distributions of collagenase 1 and collagenase 3 in cells and tissues derived from rheumatoid knee arthroplasties. Primary cultures of chondrocytes stimulated with interleukin-1 beta showed that most of the cells produced collagenase 1, whereas only a minority (approximately 5-10%) produced collagenase 3; a few chondrocytes demonstrated the co-ordinate production of both enzymes. Primary cultures of rheumatoid synoviocytes produced collagenase 1, but not collagenase 3. Both enzymes were demonstrated in the rheumatoid lesion. Collagenase 1 was more commonly observed in both synovium and cartilage (22 of the 28 specimens), was especially prominent at cartilage erosion sites, and most of the positive specimens demonstrated extracellular enzyme. By contrast, collagenase 3 was observed less frequently (7/28 specimens) and was produced by relatively few chondrocytes and synovial cells, this usually being much less than that observed for chondrocytes of osteoarthritic cartilage. These observations suggest different regulatory mechanisms for the production of collagenases 1 and 3 in the rheumatoid lesion, and demonstrate that the distribution and production of collagenase 1 are far more prevalent than those for collagenase 3.
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PMID:Comparative immunolocalization studies of collagenase 1 and collagenase 3 production in the rheumatoid lesion, and by human chondrocytes and synoviocytes in vitro. 948 53

Cartilage, bone and the interstitial stroma, composed largely of the interstitial collagens, types I, II and III, are remodelled by three members of the metalloproteinase (MMP) family, collagenase-1 (MMP-1), collagenase-2 (MMP-8) and collagenase-3 (MMP-13). MMP-1 and MMP-13 may contribute directly to disease progression, since they are induced in patients with rheumatoid arthritis and osteoarthritis. The study of MMP-1 and MMP-13 gene regulation in models of arthritic disease has been problematic because mice and rats, which are typically used, only possess a homologue of MMP-13. Here we show that in contrast with mice and rats, rabbits possess distinct genes homologous to human MMP-1 and MMP-13. Furthermore, rabbit MMP-13 is expressed simultaneously with MMP-1 in chondrocytes and synovial fibroblasts in response to the cytokines interleukin-1 and tumour necrosis factor-alpha, or the phorbol ester PMA. The time course of MMP-13 induction is more rapid and transient than that of MMP-1, suggesting that distinct mechanisms regulate the expression of these two collagenases. We have cloned the rabbit MMP-13 gene from synovial fibroblasts and demonstrated that the rabbit gene shares greater homology with human MMP-13 than does the mouse interstitial collagenase. Together with the fact that mice and rats do not possess a homologue to human MMP-1, our data suggest that the rabbit provides an appropriate model for studying the roles of interstitial collagenases in connective-tissue diseases, such as rheumatoid arthritis and osteoarthritis.
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PMID:Cloning of the gene for interstitial collagenase-3 (matrix metalloproteinase-13) from rabbit synovial fibroblasts: differential expression with collagenase-1 (matrix metalloproteinase-1). 951 98

The pseudojoint cavity formed in patients undergoing total hip arthroplasty (THA) is later remodeled to synovial membrane-like tissue, which produces pseudosynovial fluid. This pseudosynovium also is an important source of matrix metalloproteinases (MMPs). As it is widely speculated that synovial fluid MMPs may contribute to local tissue degradation in rheumatoid arthritis (RA) and osteoarthritis (OA), we hypothesize that locally produced MMPs are found in the pseudosynovial fluid, via which they have access to the implant-host interface, and that if they retain their proteolytic potential, they might contribute to aseptic loosening. Enzyme-linked immunosorbent assay (ELISA), immunoblotting, and zymography were used to analyze MMPs and tissue inhibitors of metalloproteinases (TIMPs) in synovial fluid in aseptic loosening, which was compared to RA and OA. Pseudosynovial THA fluid was characterized using low levels of MMP-1 but moderate levels of MMP-13 and MT1-MMP (MMP-14). Due to the lack of an appropriate assay, MMP-13 and MT1-MMP were not similarly assessed, but the immunoblotting indicated that they were in the 56 kD intermediate proteolytically processed forms. The MMP-9 level was intermediate between RA and OA. MMP-2 was on a significant level, but there were no differences among study groups. The THA group also was characterized using relatively high levels of TIMP-1 and TIMP-2. Accordingly, MMP-9 and MMP-2 were found to occur in the 92 kD and 72 kD proenzyme form, respectively, with full activity retained in all study groups. The data suggest that proMMP-2-TIMP-2 and proMMP-9-TIMP-1 complexes are formed in the pseudosynovial fluid due to the excess of TIMPs over MMPs in aseptic loosening of THA. TIMP-complexed MMPs are resistant to MMP-mediated proteolytic activation, which may explain their latency and proenzyme zymogen form. Thus, formation of stabilizing proMMP-TIMP complexes enable transportation of proMMPs far from their original site of production. Due to motion-associated cyclic changes of the intra-articular pressure, fluid-phase MMPs stabilized by TIMPs might be absorbed to implant surfaces and interface tissues and help to dissect the implant/cement-to-bone interface in situ. Consequently, they may contribute to local proteolytic/tissue destructive events and aseptic loosening.
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PMID:Matrix metalloproteinases and tissue inhibitors of metalloproteinases in joint fluid of the patients with loose artificial hip joints. 1039 73

Elevated MMP activities are implicated in tissue degradation in, e.g., arthritis and cancer. The present study was designed to measure MMP enzyme activity in plasma. Free active MMP is unlikely to be present in plasma: upon entering the circulation, active MMP is expected to be captured by the proteinase inhibitor alpha 2-macroglobulin (alpha 2M). Reconstituted MMP-13/alpha 2M complex was unable to degrade collagen (MW 300,000) in contrast to the low-molecular-weight fluorogenic substrate (MW < 1500). Limited access of high-MW substrates to the active site of MMPs captured by alpha 2M presents the most likely explanation. Consistently, the high-MW inhibitor TIMP (MW approximately 28,000) was unable to inhibit MMP/alpha 2M enzyme activity, whereas the low-MW inhibitor BB94 (MW approximately 500) effectively suppressed enzyme activity. By using fluorogenic substrates with Dabcyl/Fluorescein as quencher/fluorophore combin-ation, sensitive MMP-activity assays in plasma were achieved. Spiking of active MMP-13 and MMP-13/alpha 2M complex, and inhibitor studies with TIMP-1 and BB94, indicated that active MMPs are efficiently captured by alpha 2M in plasma. MMP activity was even detected in control plasma, and was significantly increased in plasma from rheumatoid arthritis patients.
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PMID:Fluorogenic MMP activity assay for plasma including MMPs complexed to alpha 2-macroglobulin. 1041 27

The assay for the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) has been shown to reflect increased type I collagen degradation in such pathological conditions as bone metastases and rheumatoid arthritis, but to be rather insensitive to the changes in physiological bone collagen turnover (e.g., induced by estrogen or bisphosphonate treatment). To determine the reasons for this discrepancy we localized the antigenic determinant recognized by the ICTP assay and studied the effects of two major osteoclastic proteinases, cathepsin K (EC 3.4.22.38) and matrix metalloproteinase-9 (MMP-9; gelatinase B; EC 3.4.24.35), on immunoreactivity. The antigenic determinant was shown to reside within the hydrophobic phenylalanine-rich regions of the carboxyterminal telopeptides of the two alpha1 chains of human type I collagen, situated between the triple helical domain and the lysine-derived trivalent cross-link. This conclusion was based on differences between the amino acid sequences and cross reactivities of the corresponding human and bovine antigens before and after proteolytic treatments with chymotrypsin. A trivalent cross-link is necessary for providing such a structure, because the divalently cross-linked and monomeric natural and synthetic peptides from the same region, but containing only one phenylalanine-rich sequence, showed poor immunoreaction. Recombinant human cathepsin K cleaved the trivalently cross-linked ICTP structure at two sites between the phenylalanine-rich region and the cross-link, destroying the reactivity with ICTP antibodies. On the contrary, the treatment of isolated ICTP by the matrix metalloproteinases MMP-9 (gelatinase B), MMP-1 (collagenase 1), or MMP-13 (collagenase 3) had no effect on the immunoreaction. Our results indicate that the increased circulating concentrations of ICTP found in several clinical situations are most likely produced by matrix metalloproteinases, whereas cathepsin K-mediated, osteoclastic bone resorption destroys ICTP antigenicity.
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PMID:Immunochemical characterization of assay for carboxyterminal telopeptide of human type I collagen: loss of antigenicity by treatment with cathepsin K. 1071 80

Oncostatin M (OSM), a member of the IL-6 superfamily of cytokines, is elevated in patients with rheumatoid arthritis and, in synergy with IL-1, promotes cartilage degeneration by matrix metalloproteinases (MMPs). We have previously shown that OSM induces MMP and tissue inhibitor of metalloproteinase-3 (TIMP-3) gene expression in chondrocytes by protein tyrosine kinase-dependent mechanisms. In the present study, we investigated signaling pathways regulating the induction of MMP and TIMP-3 genes by OSM. We demonstrate that OSM rapidly stimulated phosphorylation of Janus kinase (JAK) 1, JAK2, JAK3, and STAT1 as well as extracellular signal-regulated kinase (ERK) 1/2, p38, and c-Jun N-terminal kinase 1/2 mitogen-activated protein kinases in primary bovine and human chondrocytes. A JAK3-specific inhibitor blocked OSM-stimulated STAT1 tyrosine phosphorylation, DNA-binding activity of STAT1 as well as collagenase-1 (MMP-1), stromelysin-1 (MMP-3), collagenase-3 (MMP-13), and TIMP-3 RNA expression. In contrast, a JAK2-specific inhibitor, AG490, had no impact on these events. OSM-induced ERK1/2 activation was also not affected by these inhibitors. Similarly, curcumin (diferuloylmethane), an anti-inflammatory agent, suppressed OSM-stimulated STAT1 phosphorylation, DNA-binding activity of STAT1, and c-Jun N-terminal kinase activation without affecting JAK1, JAK2, JAK3, ERK1/2, and p38 phosphorylation. Curcumin also inhibited OSM-induced MMP-1, MMP-3, MMP-13, and TIMP-3 gene expression. Thus, OSM induces MMP and TIMP-3 genes in chondrocytes by activating JAK/STAT and mitogen-activated protein kinase signaling cascades, and interference with these pathways may be a useful approach to block the catabolic actions of OSM.
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PMID:Oncostatin M-induced matrix metalloproteinase and tissue inhibitor of metalloproteinase-3 genes expression in chondrocytes requires Janus kinase/STAT signaling pathway. 1120 8

In an effort to elucidate the role of mechanical stimuli in rheumatoid arthritis, we determined mRNA levels of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2, and three transcription factors (c-fos, ets-1, and ets-2) under two mechanical shearing conditions as well as simulated unloading. Human synovial cell cultures (MH7A and RA99-01), derived from rheumatoid arthritis patients, were grown for 1 h under mechanical stimuli and the transcript level was assayed by the reverse transcription-polymerase-chain reaction procedure. First, gentle shearing, estimated at approximately 1 dyn/cm(2), induced a consistent decrease in mRNA level of MMP-1, MMP-3, MMP-13, and ets-1 and an increase in the transcript level of TIMP-1, TIMP-2, c-fos, and ets-2. Second, intermediate shearing, estimated at approximately 6 dyn/cm(2), elevated the mRNA level of all MMPs, TIMPs, and the three transcription factors. Third, minimum mRNA level of c-fos, ets-1, and ets-2 was achieved under control conditions at rest, gentle shearing, and simulated unloading, respectively. These in vitro results support a stimulus-dependent transcriptional regulation of MMPs, TIMPs, and transcription factors in cell cultures, suggesting a potential role of shear stress in tissue degradation and prevention in rheumatic joints.
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PMID:Messenger-RNA expression of matrix metalloproteinases, tissue inhibitors of metalloproteinases, and transcription factors in rheumatic synovial cells under mechanical stimuli. 1124 61

The major pathologic manifestations of rheumatoid arthritis (RA) and osteoarthritis (OA) are joint inflammation and articular cartilage resorption by proinflammatory cytokine-stimulated matrix metalloproteinases (MMPs) and aggrecanases. The Chinese herbal remedy Tripterygium wilfordii Hook F (TWHF) is effective for treatment of various types of arthritis. However, mechanisms and targets of its actions are poorly understood. Anti-inflammatory activities of the extracts of this plant were previously attributed to inhibition of cyclooxygenase-2 mRNA and prostaglandin E(2) synthesis. Here, we show that in primary human femoral head osteoarthritic and normal bovine chondrocytes, TWHF partially or completely inhibited mRNA and protein expression of tumor necrosis factor-alpha, interleukin (IL)-1, and IL-17-inducible MMP-3 and MMP-13. This agent also inhibited cytokine-stimulated MMP-3 protein expression in human synovial fibroblasts. A dose range of 2.5 to 10 ng/ml of TWHF was effectively inhibitory for IL-1. Pretreatment for 30 min or 1 h (but not 2-10 h) after IL-1 treatment with TWHF inhibited MMP-3 RNA induction. The inhibitory doses had no adverse effect on the viability of chondrocytes. Mechanistic studies revealed no impact on the activation of extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase mitogen-activated protein kinases. Instead, TWHF partially inhibited DNA binding capacity of cytokine-stimulated activating protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) transcription factors. Therefore, besides its anti-inflammatory activity, this agent may also be effective in blocking cartilage matrix resorption by MMPs by impairing AP-1 and NF-kappaB binding activities. Thus, TWHF extract contains novel inhibitors of MMP expression that may be of therapeutic potential in arthritis and other conditions associated with increased MMPs.
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PMID:Tripterygium wilfordii Hook F extract suppresses proinflammatory cytokine-induced expression of matrix metalloproteinase genes in articular chondrocytes by inhibiting activating protein-1 and nuclear factor-kappaB activities. 1130 4


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