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ID PMID Title PublicationDate abstract
8227967 Delayed-type skin allergic reaction in guinea pigs induced by anti-rheumatic compounds wit 1993 Aug Delayed-type skin allergic (DTA) reactions induced by various sulfhydryl compounds were investigated. Sulfhydryl compounds investigated were bucillamine and D-penicillamine: antirheumatic agents, SA981: an intramolecular cyclic disulfide of bucillamine, tiopronin: a hepatoprotective and potent antirheumatic agent and captopril: antihypertensive and potent antirheumatic agent. Guinea pigs were sensitized on day 1 by subcutaneous injection and day 7 by subcutaneous and intramuscular injection of emulsions of these compounds (3 mg/animal) with Freund's complete adjuvant. Two weeks after the second sensitization, 0.3 mg/animal of each compound was intradermally challenged and the 24 hr DTA reaction was evaluated. A large number of sulfhydril compounds showed positive in the DTA reactions and the intensity of these reactions had a good correlation with the frequency of the skin rashes referred to by the adverse effects in clinical reports of anti-rheumatic drugs. It is suggested that guinea pig DTA reaction may provide a good screening way to find new sulfhydryl or disulfide compounds with low incidence of skin rash. A novel sulfhydryl compound N-(2,2-dimethyl-3-mercaptopropionyl)-L-cysteine (SA3441) and its intramolecular cyclic disulfide (4R)-hexahydro-7,7-dimethyl-6-oxo-1,2,5-dithiazocine-4-carboxylic acid (SA3443), which show no DTA activity in guinea pigs, were found using the above-mentioned DTA reaction.
8607896 Regulation of adhesion molecule expression by human synovial microvascular endothelial cel 1996 Mar OBJECTIVE: To examine the in vitro expression of E-selectin, P-selectin, intercellular adhesion molecule 1 (ICAM-1), ICAM-2, vascular cell adhesion molecule 1 (VCAM-1), and platelet-endothelial cell adhesion molecule 1 (PECAM-1) by synovial microvascular endothelial cells (SMEC) in comparison with microvascular neonatal foreskin endothelial cells (FSE) and macrovas- cular human umbilical vein endothelial cells (HUVE). METHODS: Cultured endothelial cells were treated for 4 hours with medium alone or tumor necrosis factor alpha (TNF alpha). The expression of endothelial adhesion molecules was evaluated by flow cytometry, cell enzyme-linked immunosorbent assay, and Northern blot analysis. RESULTS: SMEC continuously expressed E-selectin under basal culture conditions, whereas FSE and HUVE did not. TNF alpha treatment of rheumatoid arthritis (RA) SMEC resulted in sustained peak expression of E- selectin for up to 24 hours, which subsequently declined but remained elevated even at 72 hours. In contrast, peak E-selectin expression in FSE and HUVE occurred between 4 hours and 16 hours after TNF alpha treatment and then declined to near basal levels by 24-48 hours. SMEC expressed significantly higher levels of ICAM-1 compared with HUVE under basal culture conditions. There was no difference between SMEC, FSE, and HUVE in the expression of P-selectin, VCAM-1, ICAM-2, or PECAM-1. Northern blot analysis demonstrated that the levels of E-selectin expression by TNF alpha stimulated endothelial cells correlated with their respective messenger RNA levels. CONCLUSION: Regulation of E-selectin and ICAM-1 expression in RA synovial endothelium is different from that in neonatal foreskin and human umbilical vein endothelium. The augmented expression of adhesion molecules in RA synovial endothelium may facilitate the recruitment of leukocytes to this site.
7500028 Regulation of the balance of cytokine production and the signal transducer and activator o 1995 Dec 1 The balance between type 1 and 2 T helper cell cytokine production plays an important role in several animal models of autoimmunity, and skewed patterns of cytokine expression have been described in human inflammatory diseases. Many cytokines activate signal transducer and activation of transcription (STAT) transcription factors, which, in turn, activate transcription of inflammatory effector genes. We used mononuclear cell priming cultures and inflammatory synovial fluids (SFs) derived from arthritis patients to examine the regulation of cytokine production and STAT activity by an inflammatory synovial microenvironment. Exposure to SFs during priming resulted in an 81% inhibition of interferon (IFN)-gamma, but not interleukin (IL) 4, production by effector cells generated in priming cultures. SF suppression was mediated by IL-4 and IL-10 and inhibition of IL-12 expression, and it was reversed in a dominant fashion by exogenous IL-12. SFs blocked the sustained activity of transcription factor Stat1, but not Stat3, during the priming period, and Stat1 activity was differentially regulated by cytokines in parallel with their positive or negative regulation of IFN-gamma production. Active Stat3, but not Stat1, was detected in cells from inflamed joints. These results suggest a role for altered balance of Stat1 and Stat3 transcriptional activity in the regulation of T cell differentiation and in the pathogenesis of inflammatory synovitis.
7903132 [Circadian aspects of diclofenac gastroduodenopathy and the protective effect of roxatidin 1993 Sep The gastrointestinal side-effect profile of non-steroidal anti-inflammatory drugs should follow a circadian rhythm. In a randomized, parallel, double-blind study the gastric duodenal effects of 100 mg diclofenac retard daily in the presence and absence of 150 mg roxatidine was evaluated in 20 healthy volunteers undergoing upper GI-endoscopy. Drugs were taken over a period of 14 days either at 8 a.m. (n = 10) or at 8 p.m. (n = 10). Endoscopic controls were performed at entry and repeated after 14 days of treatment. A damaging score according to Lanza et al. was used. At entry both groups showed comparable mucosal damages: 8 a.m.-group: placebo 0.9 +/- 0.1 (+SEM), roxatidine 0.9 +/- 0.1; 8 p.m.-group: placebo 1.0 +/- 0.0, roxatidine 0.9 +/- 0.1. After 14 days of treatment the lesion score increased in the diclofenac retard/placebo-group in the 8 a.m.-group to 7.6 +/- 1.9 and in the 8 p.m.-group to 7.2 +/- 1.1. The corresponding values in the diclofenac/roxatidine-group were 2.1 +/- 0.9 (8 a.m.-group) and 1.4 +/- 0.4 (8 p.m.-group). This protection afforded by roxatidine was significant when compared with placebo (p < 0.05). Our data suggest that the gastrolesive effects of diclofenac retard are independent of the time of drug ingestion; in addition protection by roxatidine was also time-independent.
8083342 Epithelial neutrophil activating peptide-78: a novel chemotactic cytokine for neutrophils 1994 Sep We and others have shown that cells obtained from inflamed joints of rheumatoid arthritis (RA) patients produce interleukin-8, a potent chemotactic cytokine for neutrophils (PMNs). However, IL-8 accounted for only 40% of the chemotactic activity for PMNs found in these synovial fluids. Currently, we have examined the production of the novel PMN chemotactic cytokine, epithelial neutrophil activating peptide-78 (ENA-78), using peripheral blood, synovial fluid, and synovial tissue from 70 arthritic patients. RA ENA-78 levels were greater in RA synovial fluid (239 +/- 63 ng/ml) compared with synovial fluid from other forms of arthritis (130 +/- 118 ng/ml) or osteoarthritis (2.6 +/- 1.8 ng/ml) (P < 0.05). RA peripheral blood ENA-78 levels (70 +/- 26 ng/ml) were greater than normal peripheral blood levels (0.12 +/- 0.04 ng/ml) (P < 0.05). Anti-ENA-78 antibodies neutralized 42 +/- 9% (mean +/- SE) of the chemotactic activity for PMNs found in RA synovial fluids. Isolated RA synovial tissue fibroblasts in vitro constitutively produced significant levels of ENA-78, and this production was further augmented when stimulated with tumor necrosis factor-alpha (TNF-alpha). In addition RA and osteoarthritis synovial tissue fibroblasts as well as RA synovial tissue macrophages were found to constitutively produce ENA-78. RA synovial fluid mononuclear cells spontaneously produced ENA-78, which was augmented in the presence of lipopolysaccharide. Immunohistochemical localization of ENA-78 from the synovial tissue of patients with arthritis or normal subjects showed that the predominant cellular source of this chemokine was synovial lining cells, followed by macrophages, endothelial cells, and fibroblasts. Synovial tissue macrophages and fibroblasts were more ENA-78 immunopositive in RA than in normal synovial tissue (P < 0.05). These results, which are the first demonstration of ENA-78 in a human disease state, suggest that ENA-78 may play an important role in the recruitment of PMNs in the milieu of the inflamed joint of RA patients.
7994911 Perforin expression by thyroid-infiltrating T cells in autoimmune thyroid disease. 1994 Dec Infiltration of the thyroid gland by lymphocytes is a hall-mark of autoimmune thyroid disease; it is particularly evident in Hashimoto's thyroiditis but is also seen in most patients with Graves' disease. Infiltrating cells are comprised primarily of T lymphocytes, of which only a minority appears to be activated. Their precise pathogenic role is largely unknown. Since perforin has been a marker for functionally activated cytotoxic T cells in situ we elected to assess the presence of perforin-containing cells in thyroid-infiltrating lymphocytes and establish their phenotype. Cells were isolated from seven subtotal thyroidectomy specimens, five from patients with Graves' disease and two with Hashimoto's thyroiditis. The novel findings were as follows: CD4+ perforin-containing T cells occurred only in Hashimoto's glands, suggesting a class II-restricted component of cytotoxicity; in Graves' disease, and to a lesser extent in Hashimoto's, perforin-expressing cells were primarily T cell receptor alpha beta- CD4-CD8- (double negative); double negative perforin-containing cells in peripheral blood of normal individuals were largely gamma delta + T cells. In Hashimoto's samples, the predominant population of T cells expressing perforin was CD8+. By comparison, in studies of the synovial fluid of knee joints from patients with rheumatoid arthritis only a minor population of the perforin-containing cells was double-negative. The data suggest significant differences in cytotoxic autoimmune mechanisms between the two autoimmune thyroid diseases. Functional characterization of double-negative T cells is necessary to define their role in autoimmunity.
1445455 Serum anti-SS-B/La and IgA rheumatoid factor are markers of salivary gland disease activit 1992 Nov OBJECTIVE: To identify serologic markers of salivary gland disease activity in 43 patients with primary Sjögren's syndrome. METHODS: Comparison of salivary gland biopsies (focus scores) and flow rates with serum concentrations of IgA and IgM rheumatoid factor (RF), total serum IgG, serum anti-SS-B/La antibodies, and the erythrocyte sedimentation rate. RESULTS: Serum anti-SS-B/La antibody levels correlated with focus scores (rs = 0.477, P < 0.0025). Serum IgA-RF concentrations correlated inversely with stimulated parotid gland salivary flow rates (rs = -0.394, P < 0.01). CONCLUSION: Measuring serum levels of anti-SS-B/La and IgA-RF would be useful when monitoring salivary responses in therapeutic trials, especially in patients with minimal salivary function.
7686833 T-cell receptor peptide therapy in EAE and MS. 1993 Mar Synthetic peptides corresponding to germline TCR V beta 8.2 sequences overexpressed by Lewis rat encephalitogenic T cells are effective in the prevention and treatment of autoimmune encephalomyelitis (EAE). In evaluating optimal conditions for identifying disease-relevant target V beta genes, we found that the biased expression of V beta 8.2 was most pronounced in the CNS among activated, IL-2 responsive T cells, but was weakly reflected in the cerebrospinal fluid. Evaluation of basic protein reactive T cells from patients with multiple sclerosis revealed biased expression of V beta 5.2 and to a lesser degree, V beta 6.1. Treatment of 11 MS patients with synthetic TCR V beta 5.2 and V beta 6.1 CDR2 peptides boosted the frequency of anti-TCR reactive T cells in a majority of patients, without compromising recall immunity or causing side effects. TCR peptides may be useful in the treatment of human autoimmune diseases, providing that disease-relevant V genes can be identified.
8832978 Antioxidants inhibit tumor necrosis factor-alpha mediated stimulation of interleukin-8, mo 1996 Mar OBJECTIVE: To study whether the induction of mRNA for interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and collagenase by tumor necrosis factor-alpha (TNF-alpha) is suppressed by antioxidants in human synovial cells. TNF-alpha has been shown to exert some of its effects by stimulating production of reactive oxygen intermediates in some cell lines other than synovial cells. METHODS: Amounts of mRNA for IL-8, MCP-1, and collagenase were determined by Northern blot analysis. Electrophoretic mobility shift assays were performed for the detection of a transcription factor, nuclear factor-kappa B(NF-kappa B). The concentration of IL-8 in the medium was determined by ELISA. RESULTS: TNF-alpha increased the expression of IL-8, MCP-1, and collagenase mRNA in human synovial cells. NF-KB known to induce IL-8 gene transcription was also increased in nuclear extracts from the synovial cells treated with TNF-alpha. Prior addition of antioxidant, N-acetyl-L-cysteine (NAC) or 2-oxothiazolidine-4-carboxylate (OTC), suppressed TNF-alpha stimulated expressions of IL-8, MCP-1, and collagenase mRNA in a dose dependent manner. Treatment with NAC also suppressed TNF-alpha induced increase in NF-kappa B. The changes of IL-8 in the medium reflected the mRNA levels. Hydrogen peroxide (H2O2) induced the expression of mRNA for the cytokines but not collagenase mRNA, and NAC suppressed the effect of H2O2. CONCLUSION: Our data suggest that TNF-alpha induces expression of proinflammatory cytokines such as IL-8 and MCP-1 through generation of reactive oxygen intermediates and subsequent activation of NF-kappa B in human synovial cells, and the antioxidants may inhibit, at least in part, the activation of NF-kappa B by TNF-alpha. These results indicate that antioxidants such as NAC may be useful in treating rheumatoid arthritis.
8936587 Inhibition of eicosanoid release from synovial organ culture by incubation with tepoxalin 1996 Oct The pharmacological profile of a novel dual inhibitor, tepoxalin and of its carboxylic acid metabolite on cyclooxygenase and lipoxygenase pathways was evaluated by in vitro incubation with synovial tissue. Tissue specimens obtained at surgery in rheumatoid arthritis (RA, n = 10) or osteoarthritis (OA, n = 11) patients were incubated. Tepoxalin (10(-7), 10(-6), 10(-5) M) decreased eicosanoid release calculated in % of tyrode control for OA: LTC4 to 71-33%, 6-keto-PGF1a to 37-20%, PGE2 to 29-6%. For RA: LTC4 to 56-22%, 6-keto-PGF1a to 43-22%, PGE2 to 57-32%. Similarly, its metabolite (10(-7), 10(-5)M) decreased release in OA: LTC4 to 99 and 60%, PGE2 to 42 and 20%, 6-keto-PGF1a to 54 and 25%. In RA:LTC4 to 81 and 45%, PGE2 to 61 and 30%, 6-keto-PGF1a to 46 and 18%. Significance (P < 0.05) was achieved for all but 1 group (LTC4 metabolite at 10(-7)M vs tyrode). In summary a marked and dose dependent decrease of LT and PG release was obtained when incubating the dual inhibitor tepoxalin and its active carboxylic acid metabolite with synovial tissue at doses expected to be reached in the joint during therapy.
8101016 Rheumatoid inflammatory T-cell clones express mostly Th1 but also Th2 and mixed (Th0-like) 1993 Jul This study was performed in order to characterize whether T cells from rheumatoid synovial inflammation belong to the Th1- or Th2-like functional subsets. Cytokine production was studied in 26 CD4+ alpha beta+ and 2 CD8+ alpha beta T-cell clones from the synovial fluid, the synovial membrane and peripheral blood of 5 patients. Fifteen of the CD4+ clones were raised against various mycobacterial antigens and 11 CD4+ clones and 2 CD8+ clones were raised unspecifically using PHA and/or IL-2. The specificities of these clones are not known. In the mycobacterial antigen-specific group, all CD4+ alpha beta T-cell clones produced IFN-gamma at high levels, while the production of IL-4 was generally absent or low (< 1 ng/ml), consistent with a Th1-like profile. Some of these clones, however, also produced various amounts of IL-10 which has been regarded as a Th2 product but can be produced also in lower amounts by Th1 cells. One HSP-65-specific clone produced levels of IL-4 and IL-10 in the same order as that of IFN-gamma, thus appearing to be Th0-like. Among the 11 unspecific CD4+ clones, 7 showed a Th1-like pattern but with lower levels of IFN-gamma than the antigen-specific clones. However, three clones did not produce any IFN-gamma activity but produced IL-4 and one of them also produced distinct amounts of IL-10, compatible with a Th2-like pattern. In addition, one of the clones also showed an almost equally strong IFN-gamma and IL-4 production, thus most likely representing a Th0-like clone.
1565623 Human autoantibodies reactive with synthetic autoantigens from T-cell receptor beta chain. 1992 Apr 15 We used mapping with synthetic overlapping peptides in combination with molecular modeling to analyze the IgG antibodies that humans naturally produce against human T-cell receptor beta chains and to localize the recognized peptide autoantigens in the three-dimensional structure of the molecule. Healthy individuals produce low levels of antibodies against T-cell receptor peptides, and these can be increased in autoimmune diseases. We characterized the reactivities in detail because IgG molecules reactive with self peptides occur in preparations of intravenous immunoglobulin and can be isolated by immunoaffinity chromatography. Natural IgG antibodies were directed against three major peptides. One corresponds to the first complementarity-determining region of the variable region. A second corresponds to the third framework of the variable region. The third is located in the constant region and is predicted to be a loop that extends out of the beta-barrel structure. This peptide is one that would give a characteristic structural distinction between the beta-chain constant region and the constant regions of immunoglobulin light chains to which beta chains are homologous. The capacity to bind these peptides is found in small fractions of normal polyclonal IgG, which contains both kappa chains and lambda chains. The activity is antibody-like in being confined to the Fab fragment and in its capacity to discriminate among homologous synthetic peptides corresponding to distinct beta-chain variable-region genes. We propose that a recognition and regulatory process naturally occurs that parallels the immune network for the regulation of the production of antibodies.
7545920 Human rheumatoid factors with restrictive specificity for rabbit immunoglobulin G: auto- a 1994 May 1 To determine the molecular and functional properties of human rheumatoid factors (RF), we established stable hybridomas and Epstein-Barr virus-transformed B cell lines from the synovial fluid or peripheral blood of three patients with rheumatoid arthritis and one patient with systemic lupus erythematosus. 17 cell lines were obtained that produced high-titer immunoglobulin M (IgM) RF that reacted exclusively with rabbit but not human IgG or IgG of other mammalian species. Certain anti-rabbit IgG RF also had specificity for other mammalian antigens (Ag), including cytoskeletal proteins and intracellular proteins found in HeLa cells, as well as for Ag present in an extract prepared from the cell wall of group A streptococci. 13 of the 17 RF contained lambda-type light (L) chains, of which 12 were classified serologically as members of the lambda-L chain variable region (V lambda) subgroup, designated V lambda III. The heavy chain V region (VH) and V lambda sequences of nine of these IgM lambda RF were determined at the cDNA level. Five VH genes in three VH families were used by these antibodies (Ab), including VH1 (dp21/1-4b and dp10 [51p1]/hv1051), VH3 (dp38/3-15 and dp77/13-21), and VH4 (dp70/4-4b). The deduced V gene-encoded amino acid sequences of the lambda chains of these IgM lambda RF confirmed their serological classification as lambda III, and they were further classified as members of the relatively uncommon V lambda III subgroup, designated V lambda IIIb. Based on cDNA analyses, nine were the product of three different V lambda III b germline genes. Two such genes, designated hsiggll150 and hsiggll295, were cloned and sequenced from genomic DNA. Unique combinations of these VH and V lambda III b genes could be related to distinctive patterns of reactivity among the IgM lambda RF. Although the VH and V lambda regions of these Abs were expressed primarily as germline-encoded sequences, four of nine multireactive Abs had extensive V region mutation, indicative of an Ag-driven process. The finding that lambda IIIb L chains are preferentially found among anti-rabbit IgG RF, and that some of these Ab have specificity for other protein, cellular, and bacterial Ag, provides new insight into the pathogenesis of RA and related diseases.
8398197 Human autoantibodies to a synthetic putative T cell receptor beta-chain regulatory idiotyp 1993 We used synthetic peptides to analyze the human natural antibody response to V beta determinants. A major determinant recognized by IgM and IgG autoantibodies of clinically healthy individuals as well as those suffering from rheumatoid arthritis (RA) was a peptide corresponding to the first complementarity-determining region (CDR1). The natural IgM response of RA patients to this synthetic autoepitope was significantly elevated relative to that shown by healthy individuals. The levels of IgM reactivity to determinants corresponding to this region decreased with increasing age. By contrast, IgG autoantibodies to certain V beta CDR1 peptides increased markedly with age. In order to determine whether the CDR1 V beta determinant might be involved in immunization, we immunized rabbits with a human peptide that is greater than 80% identical to the homologous sequence derived from a rabbit V beta gene. As a control, the rabbits were immunized with a peptide of equal length derived from the N-terminus of the human V beta chain. Like humans, rabbits tended to have high levels of autoantibodies to the CDR1 peptide but not to the N-terminal segment. Following immunization, the rabbits produced strong IgG responses to the N-terminal peptide. By contrast, immunization with the CDR1 peptide resulted in levels of IgG antibody less than or equal to the natural activity in unimmunized rabbits. These studies indicate that the CDR1 region of Tcr V beta is a widely recognized autoantigenic portion of the Tcr that most probably functions as a regulatory epitope in man and other species.
7586741 Macrophage inflammatory protein-1 beta: a C-C chemokine in osteoarthritis. 1995 Dec The aim of this study was to determine whether the cytokine macrophage inflammatory protein-1 beta (MIP-1 beta) is present and functionally active in the arthritic joint. We used immunoassays and bioassays to assess the presence and function of MIP-1 beta using samples obtained from 62 arthritic patients. MIP-1 beta levels were increased in synovial fluids (SFs) from patients with osteoarthritis (OA) (18.0 +/- 8.9 ng/ml) (SD) compared to patients with rheumatoid arthritis (RA) 6.1 +/- 2.9 ng/ml) or other forms of arthritis (10.4 +/- 7.0 ng/ml) (P < 0.05). Levels of OA SF MIP-1 beta were significantly greater than OA or normal serum levels of MIP-1 beta. Anti-MIP-1 beta neutralized 28% of the chemotactic activity for monocytes found in OA SFs. Isolated OA synovial tissue fibroblasts did not constitutively produce MIP-1 beta but could be induced to express this chemokine upon exposure to tumor necrosis factor-alpha, interleukin-1 beta, or lipopolysaccharide. Synovial tissue immunohistochemical staining revealed that the main immunopositive cells in OA were the lining cells as well as vascular smooth muscle and endothelial cells. A minority of macrophages were immunopositive as well. In this study, we identify MIP-1 beta as a unique cytokine increased in OA compared to RA SF. We conclude that MIP-1 beta may play a role in the ingress of monocytes into the OA joint.
8607887 Interleukin-10 functions as an antiinflammatory cytokine in rheumatoid synovium. 1996 Mar OBJECTIVE: Interleukin-10 (IL-10) is an antiinflammatory cytokine that has been shown to play a role in rheumatoid arthritis (RA). We therefore investigated the effects of IL-10 on the function and phenotype of synovial fluid mononuclear cells (SFMC) derived from patients with RA. In addition, we studied the production of IL-10 in rheumatoid joints, and the role of endogenous IL-10 in the regulation of SFMC function. METHODS: The presence of IL-10 in rheumatoid joints was studied using IL-10-specific enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase- polymerase chain reaction (RT-PCR) techniques. The effects of recombinant human IL-10 or neutralizing anti-IL-10 monoclonal antibodies (MAbs) on both cytokine production and phenotype of SFMC were evaluated using cytokine-specific ELISAs and flow cytometry. The effect of IL-10 on proliferation of SFMC was determined by incorporation of tritiated thymidine. RESULTS: IL-10 was detected by ELISA in 22 of 23 SF samples, and was spontaneously produced by cultured SFMC. IL-10 messenger RNA was detectable in all 8 SFMC samples, as determined by RT-PCR. Neutralization of endogenously produced IL-10 by anti- IL-10 MAbs resulted in increased production of IL-1 beta, tumor necrosis factor alpha (TNF alpha), and granulocyte- macrophage colony-stimulating factor (GM-CSF) by SFMC, and in enhanced proliferation of SFMC. In particular, the production of TNFalpha was dramatically increased by anti-IL-10 MAbs. Moreover, the expression of HLA-DR molecules by SF macrophages was increased, and the expression of CD16 was decreased by anti-IL-10 MAbs. In contrast, addition of recombinant IL-10 significantly decreased the production of IL-1 beta, TNF alpha, and GM-CSF by SFMC, and decreased spontaneous and IL-2-induced proliferation of SFMC. Finally, IL-10 decreased HLA-DR expression and increased the expression of the Fc gamma receptors, CD16 and CD64, by SF macrophages. CONCLUSION: These data indicate that endogenously produced IL-10 functions as an immunoregulatory molecule in rheumatoid synovium. Importantly, exogenous IL-10 has potent antiinflammatory effects on SFMC, suggesting that IL-10 may be useful in the treatment of patients with RA.
1480018 Expression of stromelysin and stromelysin-2 in rabbit and human fibroblasts. 1992 Stromelysin and stromelysin 2, closely related members of the metalloproteinase gene family degrade many non-collagenous components of the extracellular matrix and may play a role in the activation of latent procollagenase. Because we use monolayer cultures of rabbit and human fibroblasts as model systems to study these enzymes, we compared their expression in fibroblasts from both species. Rabbit stromelysin purified from fibroblast culture medium often appears as a protein doublet, while human stromelysin is a single protein band. Hybrid selection with a cDNA clone for rabbit stromelysin and in vitro translation of mRNA from rabbit fibroblasts stimulated with phorbol myristate acetate (PMA) reveals two translation products, Mr54 and 56KD, as measured by SDS polyacrylamide gel electrophoresis. In vitro transcription and translation of a 1.8 kb cDNA for rabbit stromelysin gives a single protein product, preprostromelysin, MR 56KD. We do not yet know whether the rabbit doublet represents two distinct gene products or whether it results from posttranscriptional/posttranslational processing of a single transcript or protein. To study human stromelysin, we cloned a cDNA from a rheumatoid synovial cell cDNA library and we used it to isolate genes for stromelysin and a related gene, stromelysin-2. Both genes are contained on approximately 14 kilobase pairs of DNA. With an exon containing fragment of the human stromelysin-2 genomic clone as a specific probe in Northern blot analysis, we demonstrate the differential expression of stromelysin and stromelysin 2 in rheumatoid synovial cells, human foreskin fibroblasts, and rabbit synovial fibroblasts. Chimeric constructs containing 302 bp of the human stromelysin promoter DNA linked to the bacterial gene chloramphenicol acetyl transferase (CAT) can be induced by PMA, epidermal growth factor (EGF) and interleukin-1 beta (IL-1 beta). Since the genes for stromelysin and stromelysin 2 are so conserved and since mechanisms regulating their expression appear to be distinctive, identification of these mechanisms in both rabbits and humans will increase our understanding of the relative role of these enzymes in normal and disease processes.
8874384 Interleukin-4, transforming growth factor beta 1, and dexamethasone inhibit superantigen-i 1996 Oct Signalling via MHC class II in human fibroblast-like synoviocytes selectively induces interstitial collagenase gene expression over its natural inhibitor, the tissue inhibitor of metalloproteinase (TIMP), through a prostaglandin E2 (PGE2)-dependent pathway involving cyclooxygenase-2 (COX-2) and cytosolic phospholipase A2 (cPLA2). In the present study, we investigated the effect of three different agents the T-cell-derived cytokine IL-4, transforming growth factor beta 1 (TGF-beta 1), and dexamethasone (DXS) on this response. Our results indicate that treatment of superantigen-stimulated synoviocytes with DXS or IL-4 inhibited collagenase gene expression without affecting TIMP gene expression. In contrast, treatment of superantigen-stimulated synoviocytes with TGF-beta 1 resulted in an inhibition of collagenase induction and an increase in TIMP gene expression. IL-4, TGF-beta 1, and DXS abolished PGE2 production and the expression of COX-2 and cPLA2 but failed to affect the constitutive expression of COX-1 and secreted PLA2. Moreover, all agents abolished protein production and phosphorylation of COX-2 and cPLA2, respectively. The inhibitory effect of the three agents on collagenase gene expression was partially reversed by exogenous PGE2, which confirms that major histocompatibility complex class II-induced collagenase gene expression is regulated through a PGE2-mediated pathway. These data highlight a mode of action of a classical anti-inflammatory agent (DXS) and of two cytokines with recognized anti-inflammatory characters (IL-4 and TGF-beta 1) on a major histocompatibility complex class II-induced response and support the involvement of COX-2 and cPLA2 in major histocompatibility complex class II-induced interstitial collagenase production in human fibroblast-like synoviocytes.
8419336 Melanoma growth-stimulatory activity/GRO decreases collagen expression by human fibroblast 1993 Jan 15 Melanoma growth-stimulatory activity (MGSA)/GRO is well characterized as a potent neutrophil chemoattractant. In the present study, we have demonstrated that MGSA induced a dose-dependent decrease in the expression of interstitial collagens by rheumatoid synovial fibroblasts. The decrease was observed over a dose range of 0.6-6.0 nM MGSA. This effect was specific, as MGSA had no demonstrable effect on the expression of collagen-degrading metalloproteinases, nor did it affect the collagenase inhibitor, tissue inhibitor of metalloproteinases. It also had no effect on the proliferation rate of these fibroblasts, unlike its mitogenic effect on melanoma cells. The ability to inhibit collagen expression was also demonstrated by another member of the C-X-C branch of the platelet factor 4 superfamily, interleukin-8 (IL-8), but not by RANTES, MIP-1 alpha, or MIP-1 beta, which belong to the C-C branch. Steady-state levels of expression of MGSA and IL-8 transcripts in normal adult tissues were dissimilar, suggesting that expression may be an important level at which the activity of these cytokines is regulated. Direct binding experiments with 125I-MGSA on synovial fibroblasts have allowed us to identify an MGSA receptor with a KD of 10.1 nM and approximately 75,000 binding sites/fibroblast. 125I-MGSA binding was specific and could not be displaced by unlabeled IL-8. These results suggest that MGSA, as well as IL-8, may play a role other than that of neutrophil chemo-attractant and more specifically, may be important in the regulation of collagen turnover.
8091157 Multiple cause-of-death data as a tool for detecting artificial trends in the underlying c 1994 Jun The aims of the study were: (i) to identify trends in the underlying cause-of-death statistics that are due to changes in the coders' selection and coding of causes, and (ii) to identify changes in the coders' documented registration principles that can explain the observed trends in the statistics. 31 Basic Tabulation List categories from the Swedish national cause-of-death register for 1970-1988 were studied. The coders' tendency to register a condition as the underlying cause of death (the underlying cause ratio) was estimated by dividing the occurrence of the condition as underlying cause (the underlying cause rate) with the total registration of the condition (the multiple cause rate). When the development of the underlying cause rate series followed more closely the underlying cause ratio series than the multiple cause rate series, and a corresponding change in the registration rules could be found, the underlying cause rate trend was concluded to be due to changes in the coders' tendency to register the condition. For thirteen categories (fourteen trends), the trends could be explained by changes in the coders' interpretation practice: five upward, four insignificant, and five downward trends. In addition, for three categories the trends could be explained by new explicit ICD-9 rules.