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)

The distribution and amount of fibronectin in both involved and uninvolved skin from scleroderma patients and controls were compared by indirect immunofluorescence. A marked increase in fibronectin was found in the deep dermis of involved scleroderma skin, while the subepidermal papillary regions of all specimens revealed little variation in fibronectin content. The districution of the accumulated fibronectin appeared to parallel that of the accumulated collagen in the involved reticular dermis.
Arthritis Rheum 1979 Sep
PMID:Increase in fibronectin in the deep dermis of involved skin in progressive systemic sclerosis. 38 87

Fibronectin is an adhesive multifunctional glycoprotein found in the extracellular matrix of most types of cells and that exerts growth factor, differentiative and chemotactic activities toward many types of cells, including those cells found in knee joint tissue. Since fibronectin levels in the synovial fluid (SF) and on the cartilage surface of patients with osteoarthritis (OA) have been shown to be greatly increased over normal levels and since protease levels are also enhanced in diseased cartilage, we have investigated the presence of fibronectin fragments in the SF of patients with OA. We report that concentrations of at least 1 microM of 100 to 200 kDa fragments were found in all OA fluids examined. Since we have recently shown that fibronectin fragments can cause cartilage to release metalloproteinases, resulting in severe proteoglycan depletion, and others have shown that fragments also enhance metalloproteinase expression in synovial fibroblasts, the presence of these fragments suggests pathologic consequences in arthritis.
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PMID:Fibronectin fragments in osteoarthritic synovial fluid. 143 14

To determine the effect of extracellular matrix proteins on synoviocyte phenotype, a serum-free, defined-medium culture system was established. Rheumatoid synoviocytes maintained on type I collagen appeared monolayered, whereas cells maintained on fibronectin showed focus formation. Focus formation was abrogated by maintaining cells in the presence of antifibronectin. Focus formation was associated with a fibronectin-rich extracellular matrix, whereas monolayer morphology was associated with matrices containing a greater proportion of collagen. The abundant amount of fibronectin present in the synovial microenvironment may be partially responsible for the transformationlike phenotype displayed by rheumatoid synoviocytes.
Semin Arthritis Rheum 1992 Jun
PMID:Fibronectin mediates anchorage-dependent focus formation in cultured human synoviocytes. 162 84

We investigated the binding of highly purified soluble human C-reactive protein (CRP) to human neutrophils. Binding of CRP to neutrophils was rapid (50% of maximal binding occurred within 15 seconds), and complete within 5 minutes. Binding was inhibitable by excess unlabeled CRP, and nonspecific binding in the presence of a 200-fold excess of unlabeled CRP was 10% of total binding. Binding was not affected by other proteins, including albumin, fibronectin, rabbit IgG, or normal human plasma. Maximal binding required both calcium (0.5 mM) and magnesium (0.24 mM) ions. Calcium phosphorylcholine (10 micrograms/ml) or sodium citrate (10 micrograms/ml) completely dissociated bound CRP. Binding was saturable and most consistent with a 2-site model, demonstrating both a high-affinity receptor (1.4 x 10(4) sites/cell; Kd 3.7 x 10(-10) M) and a low-affinity receptor (4.2 x 10(5) sites/cell; Kd 2.5 x 10(-8) M). CRP at concentrations of 50 micrograms/ml inhibited the neutrophil superoxide production induced by phorbol ester. At concentrations of 100 micrograms/ml or greater, CRP also inhibited superoxide production in a cell-free xanthine oxidase-acetaldehyde system. These data suggest that CRP can down-regulate neutrophil oxidative capacity through interaction with receptors on neutrophils as well as by direct antioxidant activity.
Arthritis Rheum 1991 Aug
PMID:Binding of C-reactive protein to human neutrophils. Inhibition of respiratory burst activity. 165 Feb 22

A cofactor that selectively opsonizes particulate activators of the human alternative complement pathway and enhances their phagocytosis by human monocytes was identified in synovial fluids of patients with rheumatoid arthritis. The active material was present in fluids treated with protease inhibitors, was heat stable, and was unaffected by incubation with hyaluronidase. Chromatographic isolation of synovial fluid fibronectin by gelatin affinity and by immunoaffinity on antifibronectin monoclonal antibody BD4 yielded similar quantities of protein for each of 3 fluids. Synovial fluid proteins with the BD4 fibronectin epitope accounted for essentially all of the phagocytosis-enhancing activity and expressed this activity by opsonizing target activators. Additional chromatographic analyses of synovial fluid fibronectin with the BD4 epitope were carried out using Sepharose-bearing gelatin and 4 additional antifibronectin monoclonal antibodies. The opsonic materials were characterized as having 2 distinct fibronectin epitopes, which always mapped from the cell adhesive domain to the carboxyl-terminus of plasma fibronectin, but only rarely contained the gelatin binding domain.
Arthritis Rheum 1991 Jun
PMID:Identification and characterization of opsonic fibronectin in synovial fluids of patients with active rheumatoid arthritis. 171 22

The review presents literature data on studies into fibronectin in rheumatic diseases of immunocomplex genesis, its contribution to the development of abnormalities in the immune system and to hemostatic processes in the diseases. The role of fibronectin in the clearance of immune complexes, disturbed metabolism products of connective tissue, fibrin, and its monomers, cell membrane receptor proteins is emphasized. Extracorporeal heparin precipitation by using fibronectin is ascertained to be promising in removing plasma proteins in rheumatic immunocomplex diseases. A possible involvement of fibronectin in the fixation of immune complexes and DNA on the basal membranes, followed by immunocomplex inflammation, in the fibrin-induced R protein retention in the body, suppression of local immunity reactions, and development of joint ankylosis in rheumatic arthritis.
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PMID:[Fibronectin and immune complexes in rheumatic diseases]. 183 Sep 93

A quantitative spectrophotometrical method was used to study the adhesive phenotype of lymphocytes from regional lymph nodes of rats with early stage adjuvant-induced arthritis (AA), pretreated or not with cyclophosphamide (CY). The results showed that adhesion of lymphocytes from AA-sensitized lymph nodes to gelatin and collagens (type I, II, III and IV) was enhanced, especially to collagen type II. However, adhesion to fibronectin and to fibrinogen did not differ from adhesion in nontreated rats. Application of CY was found to aggravate AA development and influence the lymphocytes' adhesiveness. Adhesion was inhibited in all cases except to fibrinogen, where it was augmented, compared to the adhesion in both AA and control groups. Relationships between the lymphocyte adhesive phenotype and the expression of histological changes suggest that lymphocyte-matrix interactions could play an important role in the pathogenesis of AA development and the mechanism of CY action.
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PMID:Changes in the adhesive phenotype of regional lymphocytes in rats with adjuvant arthritis: alteration by cyclophosphamide. 187 75

Autoimmune MRL-lpr mice develop a spontaneous arthritis displaying similar articular and extra-articular features to rheumatoid arthritis in humans. In this study we used an ELISA assay to evaluate the serological responses of MRL-lpr mice to select extracellular matrix proteins associated with the joint. Significant levels of antibodies to collagens types I, II, III, IV, and V were demonstrated starting between 17 and 20 weeks of age. Moreover, the sera contained a strong reactivity to fibronectin. Responses to proteoglycans and laminin were weaker but still detectable. Specificity studies on pooled sera from MRL-lpr mice suggest that the autoantibodies produced are highly cross-reactive. The results indicate that the MRL-lpr mouse strain exhibits similar anti-extracellular matrix antibody profiles to those seen in varying frequencies in the sera and synovial fluid of patients with rheumatoid arthritis.
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PMID:Antibodies to extracellular matrix proteins in the sera of MRL-lpr mice. 200 42

Recently, a mutant fibronectin gene was identified in skin fibroblasts obtained from sclerotic lesions of 7 Japanese patients with systemic sclerosis (SSc). Two point mutations were found adjacent to the cell-attachment tetrapeptide DNA sequence in exon 7 of the fibronectin gene. In the present study, we investigated whether these point mutations are present in the fibronectin gene of Dutch patients with SSc. We were unable to demonstrate the point mutations in the Dutch SSc patients studied.
Arthritis Rheum 1991 Apr
PMID:The mutations in the fibronectin gene described in Japanese patients with systemic sclerosis are not present in Dutch patients. 201 28

Alterations in the synovial extracellular matrix (ECM) in chronic inflammatory arthritis may affect synoviocyte adhesion and may be important in the regulation of pannus growth and invasion. Immunohistochemical examination of synovium has revealed enhanced deposition of fibronectin and collagen in interstitial areas consistent with expansion of the ECM in inflammatory arthritis. In order to functionally characterize the ECM of synovium, synovial extracellular matrix was purified from pannus removed at joint replacement surgery. A prominent 140 Kd 6M guanidine extractable component was found to mediate synoviocyte adhesion in a cell-blotting assay. This 140 Kd component was identified as a form of type VI collagen. Type VI collagen appears to be a significant component of synovial ECM.
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PMID:Synovial extracellular matrix: partial characterization of matrix components and identification of type VI collagen molecular forms. 205 68


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