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

Estrogen appears to play a central role in the immune response and immune-mediated diseases. Estrogen receptors are expressed in a variety of immunocompetent cells, including CD4(+) and CD8(+) T cells and macrophages. Clinical observations indicate that some autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis, frequently remit during pregnancy but exacerbate, or have their onset during the postpartum period. Pharmacological levels of estrogen also appear to ameliorate certain autoimmune diseases. In addition, estrogen is known to suppress certain infectious diseases, as well as T cell-mediated responses toward oxazolone, keyhol lympet hemocyanin, Listeria soluble protein and purified protein derivatives. The immune basis for these phenomena is poorly understood. Based on a distinctive profile of cytokine production, data accumulated thus far have revealed modulatory effects for estrogen on the TH1-type and TH2-type cells, which represent two polarized forms of the effector specific immune response. Recent evidence indicates that estrogens inhibit the production of TH1 proinflammatory cytokines, such as IL-12, TNF-alpha and IFN-gamma, whereas they stimulate the production of TH2 anti-inflammatory cytokines, such as IL-10, IL-4, and TGF-beta. This can explain why estrogen suppresses and potentiates TH1- and TH2-mediated diseases, respectively. We hypothesize that exacerbation or suppression of inflammatory diseases by estrogen is mediated by skewing TH1-type to TH2-type response. This view represents a novel mechanism for the modulatory effect of estrogen on certain inflammatory diseases that can lead to beneficial or detrimental impacts depending on the type of immune involved. Such a concept is valuable when considering the application of combination therapies that include estrogen.
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PMID:Estrogen, a double-edged sword: modulation of TH1- and TH2-mediated inflammations by differential regulation of TH1/TH2 cytokine production. 1503 46

MRL/Mp mice bearing the Fas deletion mutant gene, lpr (MRL/lpr), spontaneously develop polyarthritis, sialoadenitis and dacryoadenitis, resembling rheumatoid arthritis (RA), and also corneal involvement such as keratopathy and scleritis, which is a major complication in RA patients. In this study, we found that the expression levels of IL-1beta and MMP-1 mRNAs in cornea were high in both MRL/lpr and MRL/Mp-+/+ strains of mice at an age younger than when they develop any inflammatory lesions. This was not true of other inbred strains, even those bearing the lpr gene, and also not of (NZB x NZW) F1 lupus mice. There was no significant difference in the expression of IL-1alpha and TGFbeta in cornea in these strains. Using crosses between MRL/lpr and C3H/HeJ-lpr/lpr (C3H/lpr) mice, at least the expression of IL-1beta was found to be under the control of the MRL genetic background, likely with a recessive mode of inheritance. Considering that IL-1beta in cornea was detected particularly in the epithelial layer, the high expression of IL-1beta in cornea is most likely involved in the genetic predisposition for corneal involvement and possibly also for arthritis in an MRL strain of mice.
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PMID:High expression of interleukin-1beta in the corneal epithelium of MRL/lpr mice is under the control of their genetic background. 1508 86

Pulmonary fibrosis is characterized by the accumulation of excessive connective tissue in the lungs. Its causes include chronic administration of some drugs for example bleomycin, cyclophosphamide, amiodarone, procainamide, penicillamine, gold and nitrofurantoin; exposure to certain environmental factors such as gases, asbestos and silica and bacterial or fungal infections. Some systemic diseases also predispose to the disease for example rheumatoid arthritis and systemic lupus erythematosus. The disease is associated with release of oxygen radicals and some mediators such as tumor necrosis factor-alpha TNF-alpha, transforming growth factor-beta TGF-beta, PDGF, IGF-I, ET-I and interleukins 1, 4, 8 and 13. The symptoms of the disease include dyspnea, non-productive cough, fever and damage to the lung cells. It is diagnosed with the aid of chest radiography, high resolution computed tomographic scanning and the result of pulmonary function tests. Drug-induced pulmonary fibrosis may involve release of free oxygen radicals and various cytokines for example IL-Ibeta and TNF-alpha via activation of nuclear transcription factor NF-beta as in the case of bleomycin and mitomycin or via release of TGF-beta as in case of tamoxifen or via inhibition of macrophages' and lymphocytes' phospholipases as in the case of amiodarone with the resultant accumulation of phospholipids and reduction of the immune system.
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PMID:Drug-induced pulmonary fibrosis. 1519 96

A relative high secretion level of IL-10 and a low secretion of TNF-alpha has been described in the synovial fluid and peripheral blood of patients with reactive arthritis (ReA), possibly contributing to the persistence of bacteria. The role of TGF-beta is less clear. We investigated these cytokines in the synovial membrane of patients with ReA and rheumatoid arthritis (RA) and tried to identify their cellular source. We used sections from the synovial membrane of 4 ReA and 4 RA patients which were double stained with immunofluorescence antibodies against cell surface markers for T cells (CD3), macrophages (CD68) and B cells (CD20) in combination with antibodies against intracellular cytokines TNF-alpha, IFN-gamma, TGF-beta, IL-4 and IL-10, and quantified these using a fluorescence microscope. A lower number of TNF-alpha-secreting cells were found in ReA compared to RA: CD3+: 1.78 +/- 0.54% versus 5.02% +/- 0.47% (p = 0.034). CD68+: 2.86 +/- 0.52 versus 5.37 +/- 0.53% (p = 0.034), CD20+ : 3.02 +/- 0.42% versus 3.58 +/- 0.48% (p > 0.05). A higher number of IL-10 positive cells were found in ReA compared to RA: CD3+: 3.27 +/- 1.5% versus 1.13 +/- 0.50% (p = 0.034), CD68+ 1.23 +/- 0.75% versus 0.83 +/- 0.35% (p > 0.05), CD20+: 3.70 +/- 1.6% versus 1.6 +/- 1.1% (p > 0.05). A difference between ReA and RA was also found for TGF-beta+ T cells: CD3+ 7.86 + 1.5% versus 1.78 + 0.35% (p = 0.032); CD20+: 7.91 + 2.1% versus 2.1 + 2.8% (p > 0.05), CD68+: 7.81% + 1.24% versus 2.12 + 0.28% (p = 0.032). In conclusion, we saw a different cytokine secretion pattern in the synovial membrane of ReA and RA. For T cells in ReA we found a cytokine secretion profile typical for T regulatory cells 1 (Tr1), with an elevated level of IL-10- and TGF-beta-secreting cells. Whether this is due to a more general difference in TNF-alpha, IL-10 or TGF-beta production which is genetically determined or regulated by T cells remains to be determined.
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PMID:An elevated level of IL-10- and TGFbeta-secreting T cells, B cells and macrophages in the synovial membrane of patients with reactive arthritis compared to rheumatoid arthritis. 1545 15

Angiogenesis plays a pivotal role in the aggressive proliferation of synovial cells in rheumatoid arthritis. We have previously reported the overexpression of inhibitor of DNA binding/differentiation (Id) in the endothelial cells within the synovial tissues of rheumatoid arthritis. In this study, we investigated the role of Id in inflammation and angiogenesis in an in vitro model using HUVECs. Vascular endothelial growth factor (VEGF) and TGFbeta induced the expression of Id1 and Id3 in HUVECs. Forced expression of Id induced proliferative activity in HUVECs accompanied by down-regulation of p16INK4a. Overexpression of Id enhanced expression of ICAM-1 and E-selectin, and induced angiogenic processes such as transmigration, matrix metalloproteinase-2 and -9 expression, and tube formation. In contrast, knockdown of Id1 and Id3 with RNA interference abolished proliferation, activation, and angiogenic processes of HUVECs induced by VEGF. These results indicated that Id plays a crucial role in VEGF-induced signals of endothelial cells by causing activation and potentiation of angiogenic processes. Based on these findings, it was proposed that inhibition of expression and/or function of Id1 and Id3 may potentially be of therapeutic value for conditions associated with pathological angiogenesis.
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PMID:Crucial role of inhibitor of DNA binding/differentiation in the vascular endothelial growth factor-induced activation and angiogenic processes of human endothelial cells. 1549 33

Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis in rheumatoid synoviocytes. In the present study, whether DFU, a tetrasubstituted furanone initially identified as a selective inhibitor of cyclooxygenase (COX)-2, interferes with transforming growth factor (TGF)-beta-mediated induction of VEGF was determined. Fibroblast-like synoviocytes (FLS) isolated from the synovial tissue of patients with rheumatoid arthritis were stimulated with TGF-beta in the presence or absence of DFU, followed by RT-PCR and ELISA assays to quantify the level of VEGF transcript and its product, respectively. DFU was found to elicit diverse activities on FLS, including inhibition of COX-2 and VEGF expression as well as COX-2 activity. The inhibition of TGF-beta-induced VEGF production by DFU was dose-dependent and abolished by exogenous prostaglandin E2. DFU was more potent than indomethacin to inhibit the VEGF production. These results suggest an in vivo potential for DFU to regulate both processes of inflammation and angiogenesis which collaboratively play important roles in the progression and perpetuation of rheumatoid arthritis.
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PMID:New cyclooxygenase-2 inhibitor DFU regulates vascular endothelial growth factor expression in rheumatoid synoviocytes. 1558 26

Mucosal administration of an autoantigen has been shown to be a powerful way of inducing tolerance in both animal and human arthritis clinical trials. Bovine or chicken type II collagen has been administered orally to rheumatoid arthritis patients, resulting in some, although in many cases rather limited, clinical improvement. Animal studies have revealed that the mechanisms that underlie induction of mucosal tolerance include clonal deletion, suppression of the proinflammatory Th1 cells, and the induction of regulatory T cells. These cells, defined as a persistently CD25-expressing subset of CD4(+) cells, are frequently anergic, may produce anti-inflammatory cytokines such as IL-10 and TGF-beta, and are likely to be agents of bystander suppression. A key feature that may affect the induction of these cells and other suppressive mechanisms is the dose of antigen administered. The results from human clinical trials suggest a daily dose of significantly less than 1 mg is optimal. Similarly data from collagen-induced arthritis studies reveal an optimal dose above and below which there is little or no immune suppression. Indeed, the incorrect dose can prime the immune response and aggravate disease. The timing and frequency of administration is also vital to the level of immune tolerance induced and the control of the pathological process. This and other findings derived from animal studies are discussed here in relation to the results from human clinical trials.
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PMID:Constraints on the efficacy of mucosal tolerance in treatment of human and animal arthritic diseases. 1568 63

Oral tolerance was first detailed almost 100 years ago, and since then, it has been shown repeatedly that feeding a wide variety of nonpathogenic antigens can inhibit subsequent systemic immune responses. All systemic immune responses are susceptible, but the degree and scope of the suppression depends on the nature and dose of the fed antigen. Oral tolerance has been described in most mammals, including humans, and it may be the homeostatic mechanism that prevents hypersensitivity to food antigens, as is found in celiac disease. A similar process may prevent the aberrant immune responses to commensal bacteria that occur in inflammatory bowel disease. The ability of oral tolerance to modulate experimental models of autoimmune and inflammatory disease has led to clinical trials in such diseases as rheumatoid arthritis, multiple sclerosis, and type I diabetes, with only variable success. Despite intense research, the exact mechanisms responsible for the systemic tolerance and the reasons why tolerance is the default response to many fed antigens remain controversial. Early studies suggested that CD8(+) "suppressor" T cells were important, but it is now accepted that it may involve either anergy/deletion of CD4(+) T cells, or the induction of regulatory CD4(+) T cells that produce IL-10 and/or TGFbeta. There may also be a role for CD4(+) CD25(+) T(reg), but how and when all these different mechanisms operate is still unclear. The ability of fed antigens to induce tolerance probably reflects their uptake by "quiescent" antigen-presenting cells in the intestine, with presentation to specific CD4(+) T cells in the absence of costimulation, or with the involvement of inhibitory costimulatory molecules. Dendritic cells in the Peyer's patches or mucosal lamina propria are the most likely APCs involved, but it remains to be determined exactly where these interactions occur and what the precise nature of the relevant dendritic cells is.
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PMID:Oral tolerance: overview and historical perspectives. 1580 29

Multiple mechanisms of tolerance are induced by oral antigen. Low doses favor active suppression, whereas higher doses favor clonal anergy/deletion. Oral antigen induces T-helper 2 [interleukin (IL)-4/IL-10] and Th3 [transforming growth factor (TGF)-beta] T cells plus CD4+CD25+ regulatory cells and latency-associated peptide+ T cells. Induction of oral tolerance is enhanced by IL-4, IL-10, anti-IL-12, TGF-beta, cholera toxin B subunit, Flt-3 ligand, and anti-CD40 ligand. Oral (and nasal) antigen administration suppresses animal models of autoimmune diseases including experimental autoimmune encephalitis, uveitis, thyroiditis, myasthenia, arthritis, and diabetes in the non-obese diabetic (NOD) mouse, plus non-autoimmune diseases such as asthma, atherosclerosis, graft rejection, allergy, colitis, stroke, and models of Alzheimer's disease. Oral tolerance has been tested in human autoimmune diseases including multiple sclerosis (MS), arthritis, uveitis, and diabetes and in allergy, contact sensitivity to dinitrochlorobenzene (DNCB), and nickel allergy. Although positive results have been observed in phase II trials, no effect was observed in phase III trials of CII in rheumatoid arthritis or oral myelin and glatiramer acetate (GA) in MS. Large placebo effects were observed, and new trials of oral GA are underway. Oral insulin has recently been shown to delay onset of diabetes in at-risk populations, and confirmatory trials of oral insulin are being planned. Mucosal tolerance is an attractive approach for treatment of autoimmune and inflammatory diseases because of lack of toxicity, ease of administration over time, and antigen-specific mechanisms of action. The successful application of oral tolerance for the treatment of human diseases will depend on dose, developing immune markers to assess immunologic effects, route (nasal versus oral), formulation, mucosal adjuvants, combination therapy, and early therapy.
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PMID:Oral tolerance. 1604 53

Rheumatoid arthritis (RA) is a connective tissue disease characterized by destruction of the joint cartilage and subsequently of the underlying bone. Cartilage destruction is due to proteolysis by enzymes called metalloproteinases (MMPs), whose production and expression are regulated by numerous local mediators such as cytokines, growth factors, prostaglandins, oxygen species, and neuropeptides. MMP activation is largely due to a stimulatory effect of cytokines including IL-1beta and TNFalpha. When these cytokines bind to their membrane receptor, they set off signaling cascades, with activation of TGFbeta-activating kinase (TAK-1), of NF-kappaB by Ikappa-B kinase, of mitogen-activated protein kinases (MAP kinases), and finally of activator protein-1 (AP-1). Tissue inhibitors of MMPs (TIMPs) specifically inhibit MMPs. The interrelations between joint inflammation and joint destruction remain poorly understood. Experimental data suggest that IL-1 may be involved chiefly in joint destruction and TNF in joint inflammation. However, TNF antagonists are potent inhibitors of joint destruction in clinical practice. These results suggest that the mediators function as a network and that inhibition of a single mediator can affect the entire web. Insights gained into the innermost mechanisms of cartilage breakdown in patients with RA have led to major therapeutic breakthroughs. Thus, TNF antagonists have proved highly effective in RA. Future progress will no doubt stem from new knowledge about the extracellular mediators and intracellular signaling pathways that lead to the production and activation of enzymes responsible for cartilage degradation.
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PMID:Cartilage breakdown in rheumatoid arthritis. 1608 81


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