Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003864 (arthritis)
69,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A chimeric Adenovirus-Simian Virus 40 (AdSV40) containing the large T antigen was used to transform rheumatoid synovial fibroblasts. A rheumatoid synovial fibroblast cell line was established by infection of primary rheumatoid arthritis (RA) synovial fibroblasts at Passage 10 with AdSV40 recombinants followed by selection in semisoft agarose cultures. The transformed cells grew anchor independent, exhibited continuous proliferation (> 65 passages) in monolayer culture, and formed multiple visible foci. The transformed synovial fibroblasts showed expression of the simian virus 40 large T antigen in the nucleus as determined by immunofluorescence staining. In addition, indirect immunofluorescence staining demonstrated that the transformed cells stained specifically with a fibroblast-specific antibody 1B10. Studies involving expression of metalloproteinases showed that collagenase and stromelysin were induced by phorbal 12-myristate 13-acetate (PMA), and such an induction was repressed by dexamethasone typical of primary RA fibroblasts. Levels of mRNAs for IL-1 beta, TNF-alpha, and c-jun were increased by PMA, and the mRNA transcripts of these genes were also repressed by addition of dexamethasone to the culture media. Our results indicate that transformed RA synovial fibroblasts display a similar gene expression pattern in response to PMA and dexamethasone as observed for untransformed primary RA synovial fibroblasts. These transformed rheumatoid arthritis synovial fibroblast cells provide an ideal cell culture model in which to test the efficacy of novel arthritis gene therapy reagents.
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PMID:Characterization of a SV40-transformed rheumatoid synovial fibroblast cell line which retains genotypic expression patterns: a model for evaluation of anti-arthritic agents. 902 33

Tumor necrosis factor-alpha is a potent cytokine, secreted primarily by activated monocytes and macrophages, that possesses a broad range of immunomodulating properties. Involvement of this cytokine has been validated in disease states such as arthritis and Crohn's disease and implicated in diverse neuroimmunological pathologies such as multiple sclerosis, Alzheimers and stroke. TNF-alpha is initially synthesized as a 26 kDa precursor molecule that is subsequently processed to the mature form by cleavage of the Ala76 Val77 bond. The 17 kDa carboxy-terminal protein is then secreted to function in a paracrine manner. The enzyme that processes precursor TNF-alpha has previously been identified as a microsomal metalloprotease called TNF-alpha converting enzyme (TACE). We have now purified and partially cloned the enzyme. TACE represents a novel target for therapeutic intervention in a variety of inflammatory and neuroimmunological diseases.
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PMID:Structural features and biochemical properties of TNF-alpha converting enzyme (TACE). 904 3

Anti-CD44 MoAb IM7 induced the loss of CD44 from mouse leucocytes thereby inhibiting leucocyte migration and joint inflammation in murine arthritis. Thus, targeting CD44 with MoAb may have potential for the treatment of patients with inflammatory joint diseases. Expression of CD44 by peripheral blood (PB) and synovial fluid (SF) leucocytes from rheumatoid arthritis (RA) patients was compared and the ability of IM7 to modulate this expression determined. RASF lymphocytes showed increased CD44 expression compared with those in PB indicative of an activated phenotype. As inflammatory SF did not up-regulate CD44 expression on PB lymphocytes, the increased CD44 expression by SF lymphocytes was a result of the selective homing of CD44(high) cells to the synovium rather than an effect of the synovial environment. RASF granulocytes showed reduced CD44 expression compared with those in PB, again indicative of an activated phenotype. However, this reduction could be induced on PB granulocytes following culture with inflammatory SF and was inhibited by anti-TNF-alpha MoAb, implying that soluble factors in inflammatory SF such as TNF-alpha induced granulocyte activation and CD44 loss. IM7 induced the loss of CD44 from lymphocytes (both from PB and SF) and granulocytes in vitro, but was subsequently re-expressed after 24 h culture in the absence of the MoAb. This loss of CD44 was blocked by serine- and metalloprotease inhibitors implying that IM7 induced the proteolytic cleavage of CD44 by a mechanism similar to that reported for the loss of CD44 from PMA-activated granulocytes. Furthermore, IM7-treated CD44(low) lymphocytes showed reduced adherence to both an endothelial cell line and RA synovial fibroblasts in vitro. The unique ability of IM7 to reduce CD44 expression by lymphocytes suggests that it could prevent lymphocyte extravasation and synovial infiltration in RA as previously reported in murine arthritis.
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PMID:CD44 expression by leucocytes in rheumatoid arthritis and modulation by specific antibody: implications for lymphocyte adhesion to endothelial cells and synoviocytes in vitro. 904 34

We examined the effects of low doses methotrexate (MTX) and indomethacin (IND) on bone mass and turnover in normal male Sprague-Dawley rats and those with adjuvant-induced arthritis. Normal and the adjuvant (heat-killed mycobacterium)-injected rats, 6 weeks of age, were given MTX at daily doses of 0.05, 0.1, or 0.2 mg/kg body weight (BW) or IND at a daily dose of 1.0 mg/kg BW. Rats were killed at the start, or at 14 and 28 days. In normal rats, the administration of these agents did not change the lumbar and femoral BMD values, nor did the serum osteocalcin or urinary deoxypyridinoline (D-Pyr) levels. Lumbar trabecular osteoclast number (Oc.N/BS) and osteoclast surface (Oc.S/BS) were decreased in the rats given IND. In the arthritic rats, the administration of MTX did not prevent an early increase of paw edema in the adjuvant-injected limb, but late inflammatory edema was alleviated in the non-injected limb. However, MTX administration at a dose of 0.1-0.2 mg/kg BW maintained an age-dependent increase in the lumbar and femoral BMD values. While serum osteocalcin levels were decreased and urinary D-Pyr values were increased in the arthritic control rats, these bone markers remained at the levels of the normal rats. Decreases in mineral apposition rate (MAR) and bone formation rate (BFR/BS) and increases in the trabecular Oc.N/BS and Oc.S/BS values were prevented by MTX. While IND almost completely prevented inflammatory paw edema, it did not improve the parameters of bone formation. An increase in osteoclasts was prevented and the osteopenia in the lumbar and the femoral bone was only partially prevented by IND. These data suggest that MTX improves bone mass and turnover in the arthritic rat, in which several cytokines that affect bone cells are involved. An increase in bone resorption may be due to prostaglandins, but bone formation defect was suggested to be due to other cytokines such as IL-1, IL-6, and TNF-alpha in this model.
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PMID:Methotrexate maintains bone mass by preventing both a decrease in bone formation and an increase in bone resorption in adjuvant-induced arthritic rats. 914 43

The objective was to evaluate tumour necrosis factor (TNF) status in patients with systemic juvenile chronic arthritis (s-JCA). Plasma levels of TNF-alpha, and serum levels of soluble TNF receptor 1 and 2 (sTNFR1 and sTNFR2) were measured using specific immunoassays in 20 patients with s-JCA, 10 with polyarticular JCA and 15 with pauciarticular JCA, and in 20 controls comparable for age. In patients with active s-JCA, circulating levels of TNF-alpha, sTNFR1 and sTNFR2 were significantly (P < 0.001) higher than those of controls. The levels of sTNFR1 and sTNFR2, but not those of TNF-alpha, were associated with the persistence and severity of systemic symptoms and were significantly correlated with prolongation of partial thromboplastin time and decrease in prothrombin activity. In two patients evaluated during a s-JCA-associated macrophage activation syndrome, a marked increase in sTNFR1 and sTNFR2 was found. Our results suggest that in s-JCA, TNF is involved in systemic manifestations, in the subclinical coagulation abnormalities, and in the development of the macrophage activation syndrome.
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PMID:Soluble tumour necrosis factor receptor levels reflect coagulation abnormalities in systemic juvenile chronic arthritis. 918 61

In several animal models of rheumatoid arthritis (RA), T cell responses to self 60-kD heat-shock protein 60 (hsp60) protect against the induction of arthritis. The nature of this suppressive T cell activity induced by self hsp60 is not clear. In the present study, T cell responses to human (self) hsp60 in RA in terms of type 1 (T1) and type 2 (T2) T cell activity were assessed. The results show that human and not bacterial hsp60-reactive synovial fluid (SF) T cells of patients with RA proliferate in the presence of the T2 cell growth factor IL-4. SF T cells stimulated with human hsp60 produced significantly lower amounts of IFN-gamma and higher amounts of IL-4 than SF T cells stimulated with bacterial hsp60 (P </= 0.002 and 0.05, respectively), and consequently a lower T1/T2 cell cytokine ratio was observed for human versus bacterial hsp60 (P </= 0.004). Additionally, human and not mycobacterial hsp60-specific T cell lines suppressed TNF-alpha production. Together, our results suggest that human hsp60, as overexpressed in inflamed synovium of patients with RA, can contribute to suppression of arthritis by the stimulation of regulatory suppressive T cell activity.
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PMID:Stimulation of suppressive T cell responses by human but not bacterial 60-kD heat-shock protein in synovial fluid of patients with rheumatoid arthritis. 921 24

The pro-inflammatory cytokines IL-1 and TNF-alpha are primary mediators of the acute phase response, the complex reaction of the mammalian organism to infection and injury. Among the genes activated by TNF-alpha and IL-1 in a variety of cells is TNF-stimulated gene 6 (TSG-6). The TSG-6 cDNA encodes a secreted 35 kDa glycoprotein which is abundant in synovial fluids of patients with various forms of arthritis and detectable in serum of patients with different inflammatory or autoimmune disorders. TSG-6 protein consists of two structural domains: a hyaluronan-binding link module, the characteristic domain of the hyaladherin family of proteins, and a C-terminal CUB domain, present in a variety of diverse proteins. TSG-6 forms a stable complex with components of the plasma protein inter-alpha-inhibitor (I[alpha]I), a Kunitz-type serine protease inhibitor. TSG-6 and I(alpha)I synergize to inhibit plasmin, a serine protease involved in the activation of matrix metalloproteinases which are part of the proteolytic cascade associated with inflammation. Recombinant human TSG-6 protein exerts a potent anti-inflammatory effect in a murine model of acute inflammation. Modulation of the proteolytic network associated with inflammatory processes may be a mechanism whereby TSG-6, in cooperation with I(alpha)I, inhibits inflammation. Activation of the TSG-6 gene by pro-inflammatory cytokines, presence of TSG-6 protein in inflammatory lesions and its anti-inflammatory effect suggest a role for TSG-6 in a negative feed-back control of the inflammatory response.
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PMID:TSG-6: an IL-1/TNF-inducible protein with anti-inflammatory activity. 924 9

Tumor necrosis factor (TNF) induces the production of two forms of soluble receptor (p55 and p75) that are present in human serum at concentrations that increase greatly in inflammatory rheumatic disease, as well as varying among healthy individuals. The purpose of this study was to evaluate the usefulness of soluble TNF receptors in distinguishing different forms of arthritis. Serum from patients with gout, rheumatoid arthritis, and osteoarthritis, and normal control subjects was analyzed for p55, p75, and TNF-alpha by enzyme-linked immunosorbent assay. Patients with gout had the highest level of soluble TNF receptor p55, while there was no significant difference in the level of this receptor between rheumatoid arthritis patients and controls. Both rheumatoid arthritis and gout patients had higher soluble TNF receptor p75 levels than osteoarthritis patients and control subjects, but there was no difference in the p75 level between rheumatoid arthritis and gout patients. Osteoarthritis patients had higher levels of p55 and lower levels of p75 than control subjects. The level of TNF-alpha in rheumatoid arthritis patients was higher than in osteoarthritis patients, gout patients, and control subjects. Determination of soluble TNF receptor levels, especially p55, might enable differentiation of rheumatoid arthritis from osteoarthritis and gout. The level of p75 cannot be utilized to differentiate rheumatoid arthritis and gout, in contrast to the results of previous investigations.
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PMID:Soluble tumor necrosis factor receptor in serum of patients with arthritis. 929 Feb 65

Arthritis spontaneously develops in mice expressing a human TNF-alpha transgene modified with the 3' untranslated region of beta-globin. We have backcrossed these mice onto the arthritis-susceptible DBA/1 background and found an acceleration of the onset of arthritis with successive generations of interbreeding. Bioactive TNF-alpha in primary synovial membrane cell cultures was significantly higher in the DBA/1 transgenic mice than in transgenic mice on the original background. Elevated levels of human TNF-alpha were accompanied by increases in synovial cell expression of murine IL-1beta and IL-6, but murine granulocyte-macrophage CSF, IFN-gamma, and IL-4 could not be detected. Interestingly, the anti-inflammatory cytokine IL-10 could be detected, but levels were not modulated by expression of the transgene. Analysis of the synovial membrane cell composition revealed that >50% of synovial cells were CD45-negative cells, presumably fibroblasts and endothelial cells, and the majority of CD45-expressing cells were neutrophils. Peritoneal macrophages and lymphocytes from the spleen, bone marrow, and lymph nodes required LPS stimulation to produce human TNF-alpha, indicating that, when activated, cells of these lineages were capable of expressing the transgene; however, few were found in synovial tissues. In contrast, fibroblasts derived from synovial tissue spontaneously released human TNF-alpha, and using immunohistochemical techniques, this cytokine was localized to fibroblast-like cells and chondrocytes. We propose that arthritis in DBA/1 human TNF-alpha transgenic mice is driven in part through the spontaneous expression of transgene by connective tissue cells, and there is little evidence of the participation of lymphocytes in this model.
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PMID:DBA/1 mice expressing the human TNF-alpha transgene develop a severe, erosive arthritis: characterization of the cytokine cascade and cellular composition. 930 Jul 10

To investigate the pathophysiologic effects of chronically elevated intra-articular levels of IL-1 beta, we used an ex vivo gene transfer method to deliver and express human IL-1 beta (hIL-1 beta) in the knee joints of rabbits. Expression of hIL-1 beta resulted in a severe, highly aggressive form of arthritis analogous to chronic rheumatoid arthritis in humans. Intra-articular manifestations included intense inflammation, leukocytosis, synovial hypertrophy and hyperplasia, and highly aggressive pannus formation with erosion of the articular cartilage and periarticular bone. Systemic effects were also observed, including diarrhea, fever, weight loss, and an increased erythrocyte sedimentation rate. In addition, the hIL-1 beta was found to induce elevated levels of both rabbit IL-1 beta and TNF-alpha in synovial fluid. Following the loss of hIL-1 beta transgene expression between 14 and 28 days post-transplantation, many of these changes began to normalize. These results suggest that chronically elevated intra-articular levels of IL-1 beta alone are sufficient to produce virtually all the pathologies found in rheumatoid arthritis, and furthermore, demonstrate that gene transfer can be used to investigate the roles of specific gene products in the pathogenesis of arthritis.
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PMID:Constitutive intra-articular expression of human IL-1 beta following gene transfer to rabbit synovium produces all major pathologies of human rheumatoid arthritis. 931 60


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