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)

Fragments of bovine plasma fibronectin produced by cathepsin D digestion are reportedly mitogenic for hamster fibroblasts. Rheumatoid arthritis synovial fluid contains many fibronectin fragments, which may contribute to the proliferation of synovial cells. We have therefore investigated the potential of fibronectin fragments to stimulate proliferation of synovial fibroblast-like cells using human material. Affinity-purified human plasma and synovial fluid fibronectin was digested with cathepsin D at pH 3.5 for 0-18 h and proteolysis stopped with pepstatin. A variety of fragments were produced ranging from 50 to 200 kDa when analysed by SDS-PAGE. The proliferative activity of various test preparations was studied using quiescent human skin and synovial fibroblasts. Tests were applied for 24 h to 10(4) cells and DNA synthesis measured by tritiated thymidine incorporation. Both undigested and peptides of fibronectin consistently failed to stimulate DNA synthesis in fibroblasts at all concentrations tested, compared with a phosphate-buffered saline control. This was in marked contrast to human synovial fluid from either rheumatoid arthritis or osteoarthritis patients, which stimulated DNA synthesis in the same system (P less than 0.01). Therefore, our data do not confirm the findings of previous studies in which animal materials were used. We can find no evidence that fibronectin fragments play a role in stimulating synovial proliferation in inflammatory arthritis.
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PMID:Synovial fluid fibronectin fragments: no evidence for a mitogenic effect on fibroblasts. 207 72

We studied the effect of fibronectin (FN) on the course of chronic nephritis (induced by daily injections of ovalbumin) and on the clearance and catabolism of immune complexes in Wistar rats. Rats with chronic nephritis were treated with FN (2.5 mg/kg/48 hours) for 15 days after proteinuria was first detected. In rats with untreated nephritis, urinary protein levels increased from 40 +/- 22 mg/day (mean +/- SD) to 339 +/- 68 mg/day during the 15 days of the study (P less than 0.0005). This statistically significant increase was not observed in rats treated with FN (mean +/- SD 58 +/- 46 mg/day to 124 +/- 112 mg/day). Rats treated with FN showed a higher total serum protein level than did the untreated animals (mean +/- SD 6.4 +/- 0.3 gm/dl versus 5.1 +/- 0.5 gm/dl; P less than 0.0125), as well as a significant reduction in mesangial and glomerular basement membrane deposits. Untreated nephritic rats demonstrated delayed plasma clearance of 125I-labeled aggregated IgG (plasma half-life [T1/2] 3.03 +/- 0.6 minutes) and less catabolism of these aggregates at 30 minutes (mean +/- SD 15 +/- 1.7%) than did the normal rats (T1/2 1.5 +/- 0.2 minutes, 22 +/- 2.8%, respectively; P less than 0.0005). Both parameters were within normal limits in the FN-treated rats (T1/2 1.6 +/- 0.4 minutes, 22 +/- 6%, respectively). In vitro, FN induced a significant increase in aggregated IgG catabolism by Kupffer cells and peritoneal macrophages from normal rats. These results show that FN reduces the proteinuria and histologic lesions of chronic nephritis in rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Arthritis Rheum 1990 May
PMID:Beneficial effect of fibronectin administration on chronic nephritis in rats. 234 23

Synovial tissue from patients with rheumatoid arthritis was enzymatically dissociated, and single cell suspensions were fractionated into subpopulations by centrifugation on continuous Percoll gradients. Five fractions (F1-F5) with densities of 0.991-0.998 gm/ml, 0.998-1.042 gm/ml, 1.042-1.062 gm/ml, 1.062-1.082 gm/ml, and 1.082-1.180 gm/ml, respectively, were prepared. F3 consistently contained the highest number of macrophages, while F2 and F4 contained substantially fewer macrophages. Macrophages present in F2, F3, and F4 were enriched by differential adherence to fibronectin-coated collagen gels. These macrophage-enriched cell preparations were found to be Fc and C3 positive, esterase positive, and peroxidase negative, to stain positively with anti-HLA-DR, anti-Leu-M3, OKM1, and OKM5 monoclonal antibodies, and to show characteristic features of macrophages by electron microscopy. Macrophages from F3 consistently induced neovascularization in rat corneas, while equal numbers of macrophages from F2 and F4 did not. Fibroblastic synovial cells and cells that did not adhere to fibronectin-coated collagen gels did not induce neovascularization. Within the rheumatoid synovium, there appears to be a major subpopulation of macrophages capable of inducing neovascularization, a process vital to the development of the rheumatoid synovial pannus.
Arthritis Rheum 1986 Apr
PMID:Stimulation of neovascularization by human rheumatoid synovial tissue macrophages. 242 91

Interstitial pulmonary fibrosis is a common manifestation of systemic sclerosis (SSc) and is a pathologic feature shared by a variety of other diseases. In these other disease processes, the glycoprotein fibronectin (FN) has been shown to be released by the alveolar macrophage, and is thus implicated in the development of fibrosis. We therefore studied the release of FN by alveolar macrophages obtained by bronchoalveolar lavage of 17 patients with SSc and 14 controls. We found that SSc alveolar macrophages released significantly more FN than did those of controls. Furthermore, the level of FN correlated positively with the level of inflammation determined by cellular analysis of lavage fluid and negatively with carbon monoxide diffusing capacity. FN may therefore play a role in the development of lung fibrosis in SSc and may be a marker of alveolitis.
Arthritis Rheum 1989 May
PMID:Spontaneous production of fibronectin by alveolar macrophages in patients with scleroderma. 271 31

Tissue deposits of basic calcium phosphate (BCP) crystals are associated with various clinical manifestations of inflammation. We addressed the possibility that native proteins modify the ability of hydroxyapatite (HA) crystals to stimulate human inflammatory cells. Neutrophil superoxide release and chemiluminescence in response to HA crystals (0.3-4.0 mg/ml) were blunted by serum and plasma. Inhibitory activity was progressively removed from serum by sequential adsorption with HA crystals, suggesting that the inhibitors were crystal-bound proteins. Thus, we characterized HA crystal-bound plasma proteins by O'Farrell gels: Fibronectin, transferrin, albumin, alpha 2-HS glycoprotein (AHSG), alpha 1-proteinase inhibitor, alpha 1-acid glycoprotein, Gc globulin, haptoglobin, and high density lipoprotein apolipoproteins were major bound species. Of these, AHSG was the most active inhibitor of HA-induced neutrophil superoxide release, and this glycoprotein partially (60%) restored inhibitory activity to HA-adsorbed serum. AHSG also bound in vitro to the related BCP crystal, octacalcium phosphate, but only minimally to calcium pyrophosphate dihydrate crystals and monosodium urate crystals. Suppressive effects on neutrophil stimulation exhibited by AHSG were also specific for BCP crystals. AHSG was present in noninflammatory synovial fluids bound to synthetic HA crystals in vitro, and AHSG could be detected on native synovial fluid HA crystals. We conclude that the binding of AHSG may modulate the inflammatory potential of BCP crystals.
Arthritis Rheum 1988 Sep
PMID:Serum and plasma inhibit neutrophil stimulation by hydroxyapatite crystals. Evidence that serum alpha 2-HS glycoprotein is a potent and specific crystal-bound inhibitor. 284 96

A mutant fibronectin gene was identified in skin fibroblasts obtained from sclerotic lesions of 7 patients with progressive systemic sclerosis. We found 2 point mutations adjacent to the cell-attachment tetrapeptide DNA sequence in the cell-binding domain of the fibronectin gene. This observation suggests that the mutant fibronectin is related to an integral component of sclerotic pathogenesis through abnormal cellular interactions.
Arthritis Rheum 1989 Mar
PMID:Mutant fibronectin gene in skin fibroblasts of sclerotic lesions from patients with progressive systemic sclerosis. 226 Oct 10

The purpose of the paper was to determine whether two clinically active antirheumatic compounds, cyclosporin-A (CS-A) and methotrexate (MTX) were efficacious in the treatment of adjuvant arthritis (AA) in rats, as measured by reduction of paw inflammation, lymphocyte activating factor (LAF) activity and the acute phase response. Parameters of the acute phase response consisted of plasma fibronectin (Fn), C-reactive protein (CRP), albumin and iron. Rats injected with Freund's complete adjuvant on day 1, developed systemic arthritis, which was quantitated by measuring non-injected paw swelling on day 17. When compared to normal animals, AA rats had significantly (P less than or equal to 0.01) increased: (1) splenic LAF activity (100% increase), (2) plasma Fn (58%), and (3) CRP (122%), as well as abnormally reduced levels of: (1) plasma albumin (53% reduction), and (2) iron (54%). Orally dosing AA rats from days 3 to 17 with the immunoregulatory drugs, CS-A (3 and 5 mg/kg) or MTX (0.5 and 1 mg/kg), significantly (P less than or equal to 0.01) reduced paw inflammation (100% reduction), increased final body wt 40-50 g over arthritic controls and decreased LAF activity from splenic leukocytes. The acute phase response, often associated with a high degree of LAF activity, was significantly (P less than or equal to 0.01) decreased by dosing with CS-A (3 and 5 mg/kg) and MTX (0.5 and 1 mg/kg). The inhibition of the acute phase response was measured by reduction of high plasma Fn levels (42-79% decrease) and CRP levels (57-100% decrease) as well as elevation of subnormal levels of plasma albumin (57-101% increase) and iron (40-114% increase). Dosing with the nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin (50 and 100 mg/kg) or phenylbutazone (10 and 30 mg/kg), significantly inhibited paw inflammation (29-85%), but did not decrease the high rate of splenic LAF activity, nor did aspirin (55, 100 and 200 mg/kg) or phenylbutazone (1, 10 and 30 mg/kg) alter the acute phase response in AA rats, as measured by levels of plasma Fn, CRP, albumin and iron. Since CS-A and MTX have been reported to be effective in the treatment of RA, their activity in the LAF, Fn, CRP, albumin and iron assays of the AA rat suggests that these immunological and serological parameters may be useful in identifying potential antirheumatic drugs and distinguishing them from standard NSAIDs.
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PMID:Alteration of interleukin-1 production and the acute phase response following medication of adjuvant arthritic rats with cyclosporin-A or methotrexate. 314 80

Twenty-six patients receiving long-term oral methotrexate (MTX) therapy for rheumatoid arthritis (24 patients) or psoriasis (2 patients) were prospectively evaluated for alterations in liver morphology by light microscopy, electron microscopy, and immunofluorescence microscopy. Although only 4 MTX-treated patients had light microscopic evidence of mild fibrosis, all had evidence of collagen deposition in the space of Disse near Ito cells and changes in hepatocyte lysosomes on electron microscopy. These findings were absent from control livers. Fibrinogen, fibronectin, and type IV collagen were identified by immunofluorescence in both MTX-treated patients and controls. We conclude that long-term MTX therapy for rheumatoid arthritis is associated with alterations in hepatic ultrastructure, including collagen deposition in the space of Disse and changes in hepatocyte lysosomes.
Arthritis Rheum 1988 Dec
PMID:Hepatic ultrastructure after methotrexate therapy for rheumatoid arthritis. 319 65

Supernatants from the P388D1 murine macrophage cell line as well as commercially prepared human interleukin-1 (IL-1) stimulated primary rabbit articular chondrocytes to produce collagen- and proteoglycan-degrading proteases. The P388D1-derived factor had a molecular weight of 16,000-20,000 and a pI of 4.5-5.0, and was sensitive to phenylglyoxal treatment. Human IL-1 and the P388D1 supernatants enhanced glycosaminoglycan (GAG) release from bovine nasal cartilage explants. The proteoglycan- and collagen-degrading proteases required Ca2+ for activity. Latent proteoglycanase and collagenase had molecular weights of 44,000-56,500 and 34,000-44,000, respectively. The activated proteases had molecular weights of 30,000-40,000 and 22,000-36,000, respectively. Heparin-Sepharose affinity chromatography yielded two latent proteoglycanase-degrading protease activities and a collagen-degrading peak. The two proteoglycanase peaks also degraded fibronectin, laminin, gelatin, and azocoll but not type I collagen. The collagenase peak also degraded proteoglycan, gelatin, fibronectin, laminin, and azocoll. The activity of the proteoglycan- and collagen-degrading peaks was inhibited by phenanthroline and alpha 2-macroglobulin but not by phenylmethylsulfonylfluoride (PMSF), tosyllysylchloromethylketone (TLCK), pepstatin, or alpha 1-antitrypsin. The control of factors which augment protease production may offer a novel therapeutic approach to arthritis.
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PMID:Interleukin-1 stimulates the secretion of proteoglycan- and collagen-degrading proteases by rabbit articular chondrocytes. 353 22

Binding of biotin-labelled native and denatured collagen type II and of aggregated IgG to frozen sections of synovial tissue from patients with rheumatoid arthritis (RA) or juvenile chronic arthritis (JCA) was investigated with the help of an avidin-biotin-peroxidase (ABC) technique. A large number of lymphocyte-like and plasma cell-like cells within the investigated biopsies aggregated IgG, and can be assumed to produce rheumatoid factors. In five out of six cases a smaller number of lymphocyte-like and plasma cell-like cells bound native collagen type II. Denatured collagen type II bound mainly to cells within the synovial lining and to endothelial cells within the inflamed synovial tissues. Binding of denatured but not of native collagen II was abolished by preincubation with rabbit antibodies towards human fibronectin. It is suggested that the method described here, using biotinylated antigens, may be of value for the study of local antibody production via investigations on frozen tissue sections, and that local antibody production against native collagen type II occurs within the inflamed synovial tissues at least in some cases of rheumatoid arthritis and juvenile chronic arthritis.
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PMID:Binding of collagen type II to rheumatoid synovial cells. 379 24


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