Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0003873 (rheumatoid arthritis)
 53,068 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mast cells have been implicated in a number of diseases involving chronic inflammation including asthma, rheumatoid arthritis, and inflammatory bowel diseases. They are a potent source of several cytokines, including IL-6 and TNF-alpha. Freshly isolated rat peritoneal mast cells will produce IL-6 in response to anti-IgE, LPS, PGE1, or PGE2; however, the mechanisms by which such cytokine production is regulated are poorly understood. IL-10 is recognized as an important immunoregulatory cytokine with effects on T cell development and the production of inflammatory cytokines. IL-10 has previously been described to enhance mast cell development in the context of IL-3 and IL-4. In the current study, we have examined the ability of IL-10 to modulate rat peritoneal mast cell IL-6 and TNF-alpha production in response to a variety of stimuli. We have observed that recombinant murine IL-10 can inhibit the production of both IL-6 and TNF-alpha by mast cells without altering the degree of histamine release in response to anti-IgE. Concentrations of IL-10 as low as 0.2 ng/ml were sufficient to inhibit IL-6 production by LPS- or anti-IgE-activated cells significantly. IL-10 also inhibited PGE1- and PGE2-induced IL-6 production. The relative potency of IL-10 as an inhibitor of mast cell IL-6 production was highly dependent upon the stimulus used, with a 10-fold difference in the IC50 for LPS- or anti-IgE-activated cells (0.21 ng/ml) and cells activated with a combination of LPS and PGE2 (2.29 ng/ml). This suggests that prostanoids may limit the ability of IL-10 to modulate mast cell IL-6 production in the context of inflammation. These data have important implications for the regulation of mast cell IL-6 in inflammatory diseases involving prostanoid production and the effects of treatment with cyclooxygenase inhibitors. Our results also demonstrate a dual role for IL-10 on mast cells as a growth factor and inhibitor of cytokine production.
 ...
PMID:Interleukin (IL)-10 inhibits long-term IL-6 production but not preformed mediator release from rat peritoneal mast cells. 861 37

The primary thrombocytosis (thrombocythemia) associated with myeloproliferative disorders is believed to be due to autonomous platelet production. Secondary or reactive thrombocytosis can be observed in a number of clinical circumstances, and may be related to persistent overproduction of some thrombocytopoietic factors acting on megakaryocytes. Several cytokines, including IL-6, IL-1 and IL-4 have been shown to act alone or in concert, to affect various cellular stages of megakaryocytopoiesis in humans. The aim of this study is to assess the serum concentrations of these cytokines in myeloproliferative disorders (MPD) with thrombocythemia and in rheumatoid arthritis (RA) with marked reactive thrombocytosis. Twenty-two patients (14 men, 8 women) with MPD and thrombocythemia (platelet counts > 500 x 10(9)/1; range 507-996 x 10(9)/1), 33 RA patients (28 women, 5 men) with marked thrombocytosis (platelet counts > 500 x 10(9)/1; range 500-745 x 10(9)/ 1), 27 RA patients (24 women, 3 men) with normal platelet counts (range 168-399 x 10(9)/1) and 15 healthy volunteers (8 women, 7 men) with normal platelet counts (range 161-385 x 10(9)/1) enrolled in the study. Serum IL-1 alpha, IL-1 beta, IL-4 and IL-6 concentrations were measured in these four groups. Of the 22 patients with MPD, 10 had chronic myelogenous leukemia, 5 had polycythemia vera, 6 had essential thrombocytosis and 1 had osteomyelofibrosis. Serum interleukin concentrations in patients with MPD and thrombocythemia were either suppressed or similar to those of normal subjects, whereas IL-6, IL-1 beta and IL-4 levels were increased in RA patients with reactive thrombocytosis. We conclude that thrombocythemia associated with MPD is an autonomous phenomenon, and is not regulated by cytokines which affect megakaryocytopoiesis.
 ...
PMID:Megakaryocyte-related interleukins in reactive thrombocytosis versus autonomous thrombocythemia. 863 38

Decreased systemic immune responsiveness to a specific antigen following exposure to that antigen by the enteric route is termed 'oral tolerance.' Oral tolerance is revealed when attempts are made to parenterally immunize the host to the same antigen that was previously administered orally or intragastrically. A similar phenomenon is also seen following antigen exposure via the nasal mucosa and a related phenomenon is seen following antigen exposure in the upper respiratory tract. There has been a marked renewal of interest in the mechanisms that underlie oral tolerance because of its potential role for preventing and treating autoimmune and inflammatory diseases and IgE-mediated allergic disorders. The specific factors that determine whether or not the host develops mucosal tolerance to an antigen administered by the mucosal route are also of substantial importance for those involved in mucosal vaccine development. Furthermore, putative abnormalities in the ability of the host to develop mucosal tolerance may play a pathogenetic role in certain autoimmune and allergic diseases and disorders. Several well-defined immunological mechanisms mediate oral tolerance. These include the induction, following mucosal antigen exposure, of regulatory populations of T-cells that can down-regulate specific immune responses (e.g. DTH) via the production of specific cytokines (e.g. TGF-beta 1, IL-10 and IL-4). In addition, clonal anergy, clonal deletion and antibody-mediated suppression can be shown to play a role in the induction and maintenance of mucosal tolerance in several experimental systems. In animal studies, the onset of collagen-induced, adjuvant-induced, antigen-induced and pristane-induced arthritis has been delayed and the severity of ongoing disease diminished following feeding collagen type II. Mucosal tolerance has been clearly demonstrated in humans and clinical studies have been undertaken to treat rheumatoid arthritis using a similar approach. Results of initial clinical studies in rheumatoid arthritis indicated a modest improvement and further studies are ongoing in this and other autoimmune diseases (e.g. multiple sclerosis, autoimmune uveitis and insulin-dependent diabetes). This approach, if successful, could offer a new and novel therapeutic modality for preventing autoimmune and allergic disorders, and modulating ongoing disease.
 ...
PMID:Oral tolerance: mechanisms and possible role in inflammatory joint diseases. 867 48

A variable region gene of the T-cell receptor, V beta 8.2, is rearranged, and its product is expressed on pathogenic T cells that induce experimental autoimmune encephalomyelitis (EAE) in H-2u mice after immunization with myelin basic protein (MBP). Vaccination of these mice with naked DNA encoding V beta 8.2 protected mice from EAE. Analysis of T cells reacting to the pathogenic portion of the MBP molecule indicated that in the vaccinated mice there was a reduction in the Th1 cytokines interleukin-2 (IL-2) and interferon-gama. In parallel, there was an elevation in the production of IL-4, a Th2 cytokine associated with suppression of disease. A novel feature of DNA immunization for autoimmune disease, reversal of the autoimmune response from Th1 to Th2, may make this approach attractive for treatment of Th1-mediated diseases like multiple sclerosis, juvenile diabetes and rheumatoid arthritis.
 ...
PMID:Suppressive vaccination with DNA encoding a variable region gene of the T-cell receptor prevents autoimmune encephalomyelitis and activates Th2 immunity. 870 50

Nitric oxide (NO) is a critical mediator of a variety of biological functions. A range of micro-organisms, including viruses, bacteria, protozoa and helminths, is sensitive to NO produced by macrophages activated with gamma-interferon (IFN-gamma) and lipopolysaccharide. In contrast, NO is involved in a number of important immunopathologies, including diabetes, graft-vs-host reaction, rheumatoid arthritis, systemic lupus erythematosus, experimental autoimmune encephalomyelitis and multiple sclerosis. Thus, it is crucial that the synthesis of NO is under tight regulation. This is achieved, in part, through the opposing cytokines produced by T helper 1 (Th1) and Th2 cells. Th1 cells produce IFN-gamma, which is the most powerful inducer of inducible NO synthase (iNOS). In contrast, interleukin 4 is produced by Th2 cells and inhibits the induction of iNOS at the level of transcription. Furthermore, NO is also produced by Th1 cells, whose proliferation can be inhibited by high concentrations of NO. Thus, apart from being a mediator of Th1/Th2 interaction, NO may also be an important self-regulatory molecule that prevents the over-expansion of Th1 cells which are implicated in a range of severe immunopathologies.
 ...
PMID:Nitric oxide in infectious and autoimmune diseases. 872 41

Immunofluorescence analysis of CD27 expression by CD4 lymphocytes from the peripheral blood of healthy humans or rheumatoid arthritis (RA) patients and from the synovial fluid (SF) of RA patients was carried out, along with the estimation of cytokine gene [interleukin (IL) 2, IL-3, IL-4, IL-5, IL-6, IL-6R, IL-10 and interferon-gamma (IFN-gamma)] expression in these lymphocyte subsets by RT-PCR. Although no differences in CD27-positive and -negative peripheral blood CD4 cell subset distribution were revealed, marked differences in IL-3, IL-4, IL-5 and IFN-gamma mRNA expression were detected between these lymphocyte subsets and between control and disease states. These results showed that phenotyping of different cell subsets in disease cannot provide adequate information about lymphocyte functional status. To estimate differences in cytokine gene expression, CD4 lymphocytes from the peripheral blood and SF of RA patients were compared. In both cases, mRNAs for IL-2, IL-4, IL-10 and IFN-gamma were detected, but CD4 cells from SF failed to express detectable levels of IL-5 mRNA despite our findings of a CD27-cell accumulation within the synovial population of CD4 lymphocytes. These are the first data to demonstrate that expression of the IL-5 gene in RA SF CD27- lymphocytes is down-regulated and that IL-5 disregulation in RA cannot be ruled out.
 ...
PMID:Differential expression of cytokine genes in CD27-positive and -negative CD4 lymphocyte subsets from healthy humans and rheumatoid arthritis patients. 877 53

Particular interleukins, namely interleukin (IL)-6, IL-4 and IL-1, with pro-inflammatory mediator activities have also been shown to be involved in the regulation of megakaryocytopoiesis. As rheumatoid arthritis (RA) is not uncommonly associated with reactive thrombocytosis, we investigated serum IL-1 alpha, IL-1 beta, IL-4 and IL-6 concentrations in RA patients with marked thrombocytosis, and compared them to the levels in RA patients with normal platelet counts and healthy volunteers. IL-1 beta. IL-4 and IL-6 concentrations were found to be correlated with the disease activity in both groups of RA patients, with higher serum levels of each cytokine in the thrombocythaemic group. Significant positive correlations of IL-1 beta and IL-4 with the platelet counts were documented only in patients with thrombocytosis. According to our results. IL-6 and IL-1 beta were found to be good indicators of disease activity in RA, while IL-1 beta and IL-4 seemed to be related more with the process of reactive thrombocytosis secondary to rheumatoid inflammation.
 ...
PMID:Cytokines affecting megakaryocytopoiesis in rheumatoid arthritis with thrombocytosis. 878 15

A subset of patients with rheumatoid arthritis occasionally develops skin reactions and glomerulonephritis and exhibits an increase in serum IgE concentration when treated with gold salts. Brown-Norway (BN) rats injected with aurothiopropanolsulfonate (ATPS) also manifest an autoimmune glomerulonephritis and increased serum IgE concentration, whereas Lewis (LEW) rats are resistant to complications. Here, we show linkage between responses to ATPS in a (BN x LEW) F2 cohort and the major histocompatibility complex (RT1) on rat chromosome 20 and between markers in the region of IL4 and other candidate genes on rat chromosome 10. Recently, human serum IgE concentration has been reported to be linked to the IL-4 region. Taken together, these findings raise the possibility that homologous genes could be implicated in ATPS manifestations in the rat and in the regulation of IgE levels in the human.
 ...
PMID:Serum IgE concentration and other immune manifestations of treatment with gold salts are linked to the MHC and IL4 regions in the rat. 880 87

Articular chondrocytes from nine arthritic patients, five infants, and Balb/c neonatal mice were analyzed for the presence of various cytokine mRNAs by a reverse transcriptase polymerase chain reaction (RT-PCR). Four cytokine mRNAs, interleukin (IL)-6, IL-8, IL-11, and macrophage colony stimulating factor (M-CSF), were detected in all human chondrocytes, regardless of source. IL-10, IL-12p35, and tumor necrosis factor alpha (TNF-alpha) transcripts were found in at least 12 of the 14 human samples. IL-13, granulocyte colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF), and TNF-beta mRNAs were found more predominantly in infant samples and in samples from patients with rheumatoid arthritis (RA) compared with samples from patients with osteoarthritis (OA). Another group of cytokine mRNAs, IL-1 (alpha, beta), IL-4, IL-5, and IL-7, were only weakly expressed in some human samples. The cytokine transcripts that were not found were IL-2, IL3, and interferon gamma (IFN-gamma). Because of the large array of cytokine transcripts detected, human chondrocyte preparations were further purified by reacting them with a monoclonal antibody specific to chondrocyte differentiation antigen and subjecting them to fluorescent-activated cell sorting. A similar array of cytokines was found between the sorted and unsorted chondrocytes, although TNF-alpha, G-CSF and GM-CSF transcripts appeared to be upregulated during the sorting process. Human chondrocytes that dedifferentiated into fibroblasts (a 40-day and a 77-day culture) no longer expressed mRNAs for IL-1, G-CSF, GM-CSF, and TNF-alpha, but all other cytokine mRNAs remained detectable. Although certain phenotypic characteristics were lost, including reactivity to chondrocyte-specific monoclonal antibodies and morphological features, chondrocytes in long-term culture still expressed cytokine mRNAs. As expected, more consistent results were obtained when seven preparations of chondrocytes from neonatal Balb/c mice were examined using available cytokine primers. They contained IL-1, IL-5, IL-6, IL-7, IL-12, GM-CSF, M-CSF, transforming growth factor beta (TGF-beta), TNF-alpha, and TNF-beta mRNAs but lacked IL-2, IL-3, IL-4, IL-10, and IFN-gamma mRNAs. Future experiments to define conditions by which these cytokine protein products are expressed are needed to help assess their roles in chondrocyte biology and in disease states.
 ...
PMID:Cytokine mRNA repertoire of articular chondrocytes from arthritic patients, infants, and neonatal mice. 885 28

Rheumatoid arthritis is characterized by a mononuclear infiltrate in the synovial tissue of the affected joints, considerable thickening of the synovial lining layer and concomitant destruction of cartilage and bone. Macrophages probably play a central role and the contribution of the synovial lining macrophages is addressed in studies in experimental murine arthritis models. Emphasis is given to the involvement in arthritis expression and cartilage destruction. The role of TNF-alpha and IL-1, and the modulatory cytokines IL-4/ IL-10 is briefly discussed.
 ...
PMID:The role of macrophages in chronic arthritis. 893 61


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>