Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0009324 (ulcerative colitis)
17,300 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Curcumin (diferulolylmethane) demonstrates profound anti-inflammatory effects in intestinal epithelial cells (IEC) and in immune cells in vitro and exhibits a protective role in rodent models of chemically induced colitis, with its presumed primary mechanism of action via inhibition of NF-kappaB. Although it has been demonstrated effective in reducing relapse rate in ulcerative colitis patients, curcumin's effectiveness in Crohn's disease (CD) or in Th-1/Th-17 mediated immune models of CD has not been evaluated. Therefore, we investigated the effects of dietary curcumin (0.1-1%) on the development of colitis, immune activation, and in vivo NF-kappaB activity in germ-free IL-10(-/-) or IL-10(-/-);NF-kappaB(EGFP) mice colonized with specific pathogen-free microflora. Proximal and distal colon morphology showed a mild protective effect of curcumin only at 0.1%. Colonic IFN-gamma and IL-12/23p40 mRNA expression followed similar pattern ( approximately 50% inhibition at 0.1%). Secretion of IL-12/23p40 and IFN-gamma by colonic explants and mesenteric lymph node cells was elevated in IL-10(-/-) mice and was not decreased by dietary curcumin. Surprisingly, activation of NF-kappaB in IL-10(-/-) mice (phospho-NF-kappaBp65) or in IL-10(-/-);NF-kappaB(EGFP) mice (whole organ or confocal imaging) was not noticeably inhibited by curcumin. Furthermore, we demonstrate that IL-10 and curcumin act synergistically to downregulate NF-kappaB activity in IEC and IL-12/23p40 production by splenocytes and dendritic cells. In conclusion, curcumin demonstrates limited effectiveness on Th-1 mediated colitis in IL-10(-/-) mice, with moderately improved colonic morphology, but with no significant effect on pathogenic T cell responses and in situ NF-kappaB activity. In vitro studies suggest that the protective effects of curcumin are IL-10 dependent.
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PMID:Limited effects of dietary curcumin on Th-1 driven colitis in IL-10 deficient mice suggest an IL-10-dependent mechanism of protection. 1881 16

Ulcerative colitis (UC) and Crohn's disease (CD) are considered to be immunologically mediated disorders that share certain features with murine models of colitis. Whether any of these models are physiologically relevant to the human condition remains controversial. The hypothesis is that increased amounts of antibodies neutralizing transforming growth factor (TGF)-beta, interleukin (IL)-2 or IL-10 create a relative immunodeficient state in inflammatory bowel disease (IBD) that predisposes to disease. To evaluate this, serum samples from patients with UC or CD and from normal healthy individuals were studied by enzyme-linked immunosorbent assays. Antibodies recognizing TGF-beta were most prevalent in UC (P<0.01); anti-IL-10 antibodies were elevated in CD (P<0.05), while anti-IL-2 antibodies were the same for all three groups. Importantly, the percentage of IBD patients with at least one of the antibody levels greater than any control value was 30% for UC and 33% for CD. To verify the presence of these antibodies, immobilized TGF-beta was exposed to UC sera and the attached proteins identified by Western blot assay. The proteins proved to be exclusively immunoglobulin (Ig) G. To evaluate the neutralizing activity of these antibodies, cytokine-specific IgG from subjects in each group of patients was incubated with TGF-beta, IL-2 or IL-10 before addition to a bioassay with changes in viability determined by a colorimetric analysis. Antibodies from most individuals in all three groups neutralized the action of each cytokine. This study shows that about one-third of IBD patients may have a relative deficiency of TGF-beta, IL-2 or IL-10 due to an increase in neutralizing antibodies in their sera.
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PMID:Patients with inflammatory bowel disease may have a transforming growth factor-beta-, interleukin (IL)-2- or IL-10-deficient state induced by intrinsic neutralizing antibodies. 1907 30

Multiple genetic studies in humans indicate a role for solute carrier family 11a member 1 [SLC11A1; formerly natural resistance-associated macrophage protein 1 (NRAMP1)] in autoimmune disease susceptibility, including ulcerative colitis. Murine Slc11a1 has many pleiotropic effects on macrophage activation and proinflammatory responses. To determine which of these are important in ulcerative colitis, we established a phenotype for oral dextran sulfate sodium (DSS)-induced acute colitis in congenic Slc11a1 wild-type (wt) and mutant (mt) mice on a B10 background. For over 7 days of treatment with 2% DSS in the drinking water, Slc11a1 wt mice showed enhanced acute ulcerative colitis, as demonstrated by significantly greater body weight loss and reduction in colon length, as well as a marked increase in monocyte/macrophage inflammatory infiltrates and histopathology changes in the colon. This was accompanied by a clear, inverse relationship between IFN-gamma and IL-10 responses in Slc11a1 wt compared with mt mice, resulting in a significantly higher ratio of IFN-gamma:IL-10 in wt compared with mt mice in lymph node and splenic T cells. RNase protection assays confirmed the presence of significantly higher IFN-gamma at the RNA level in the colons of wt compared with mt mice at Day 7 of treatment. Interestingly this was accompanied by significantly enhanced RNA levels for the acute-phase protein IL-6, which is known to inhibit the generation of forkhead box P3+ regulatory T cells and help to drive the differentiation of Th17 from naive T cells and not by differences in RNA for IL-12p35 or IL-12p40 molecules that dimerize to form the Th1-inducing cytokine IL-12.
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PMID:Influence of Slc11a1 (formerly Nramp1) on DSS-induced colitis in mice. 1911 31

Infliximab, a chimeric monoclonal antibody against TNF-alpha, is efficacious in Crohn's disease (CD) and rheumatoid arthritis (RA). Its main mechanism of action is thought to be the induction of apoptosis. The present study evaluates in detail the effects of infliximab on the TNF-alpha system using peripheral blood monocytes and T cells as well as lamina propria lymphocytes from normal individuals and patients with CD, ulcerative colitis, and RA. Lymphocytes were studied in the resting state in the absence of strong stimuli that may obscure subtle findings. Infliximab did not change the numbers of viable cells. Rather, it caused monocytes to increase their release of soluble TNFR2, which serves to neutralize TNF-alpha, potentiating the action of infliximab. It reduced TNFR2 expression, thereby decreasing TNF-alpha responsiveness. These changes were due to upregulated production of TNFR2 rather than increased shedding. Infliximab did not cause rebound production of TNF-alpha transcripts that would counteract its effects. It specifically enhanced production of IL-10 but not proinflammatory cytokines secreted by leukocytes, thereby promoting an anti-inflammatory microenvironment. In addition, infliximab caused a rise in c-Jun amino-terminal kinase phosphorylation by monocytes. Thus infliximab manipulates the TNF-alpha system to promote its anti-TNF-alpha effects.
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PMID:Infliximab and the TNF-alpha system. 1913 78

Nitric oxide (NO) derived from the inducible NO synthase (iNOS) is an important and complex mediator of inflammation in the intestine. Wnt-inducible secreted protein (WISP)-1 (CCN4), a member of the connective tissue growth factor family, is involved in tissue repair. We sought to determine the relationship between iNOS and WISP-1 in colitis. By analyzing human colonic biopsy samples, we showed that the expression of mRNA for both iNOS and WISP-1 was significantly higher in ulcerative colitis samples compared with control tissue. The upregulation of WISP-1 was positively correlated with iNOS expression in two models of colitis, induced by intrarectal trinitrobenzenesulfonic acid (TNBS) or occurring spontaneously in IL-10 deficient mice. Loss of iNOS, studied using iNOS(-/-) mice in both TNBS-induced and IL-10(-/-) colitis models, significantly attenuated the colitis-related WISP-1 increase. In human colonic epithelial cell lines, the NO donor, DETA-NONOate, elevated WISP-1 mRNA and protein expression through a beta-catenin and CREB-dependent, but Wnt-1-independent, pathway. In addition, NO-induced WISP-1 directly induced secretion of soluble collagen in colonic fibroblast cells. NO increases WISP-1 expression both in vitro and in vivo, suggesting a new role for iNOS and NO in colitis.
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PMID:Nitric oxide increases Wnt-induced secreted protein-1 (WISP-1/CCN4) expression and function in colitis. 1923 44

Crohn's disease (CD) is associated with a higher type-1-helper T cell (Th1) cytokine expression, whereas ulcerative colitis (UC) appears to express a modified Th2 response. In addition to its classic role in calcium homeostasis, calcitriol, the hormonal active form of vitamin D, exerts immunoregulatory effects such as modulation of Th1/Th2 cytokines. Therefore, calcitriol administration could modify immune dysfunction in CD and UC. Nine patients with UC (M/F: 5/4; mean age 47 years, remission(R)/active(A) disease: 7/2), 8 patients with CD (M/F: 2/6; mean age 36, R/A 5/3) and 6 healthy controls (HC) (M/F: 3/3, mean age 4) were enrolled. Peripheral blood was collected after a drug-washout of 15 days and peripheral blood mononuclear cells were stimulated with mitogens alone or in the presence of physiological concentrations of calcitriol (100 pg/ml). Type 1 (IL-2, TNF-alpha, IFN-gamma) and type 2 (IL-10) cytokine production was assayed on supernatants by ELISA. Compared to HC, TNF-alpha production was significantly higher both in UC (p=0.0002) and CD (p=0.0001) patients, at baseline and after incubation with calcitriol (UC p=0.0003, CD p=0.0009). The effects of calcitriol incubation were: 1) reduced IFN-gamma (p=0.024) and increased IL-10 (p=0.06) production in UC patients; 2) reduced TNF-alpha production in CD (p=0.032); 3) no significant effects in HC. Calcitriol increased, albeit not significantly, IL-10 production in UC compared to CD patients (p=0.09). These results suggest an important modulatory role of vitamin D in the Th1/Th2 immune response. The observation that the effect of this modulation was different in CD compared to UC patients provides an interesting area of research into the pathogenesis and treatment of these inflammatory conditions.
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PMID:Immunomodulatory effects of 1,25-dihydroxyvitamin D3 on TH1/TH2 cytokines in inflammatory bowel disease: an in vitro study. 1930 53

Ulcerative colitis (UC), Crohn's disease (CD) and indeterminate colitis are defined as inflammatory bowel diseases (IBD). Those diseases involve disorders of numerous immunological mechanisms associated with cellular and humoral immune response. In CD cellular response is considered to be of crucial importance, and dominant cytokines include: tumor necrosis factor alpha (TNF-alpha), interferon gamma (INF-gamma) and interleukins 1beta (IL-1beta), IL-2, IL-6, IL-8, IL-12. In UC, increased expression of Th2 (responsible for humoral response) is observed. It is connected with increased production of interleukins: 4 (IL-4), IL-5, IL-6, IL-10 and TNF-alpha. Lack of balance between pro-inflammatory and anti-inflammatory cytokines is of vital importance in pathogenesis of IBD. Conventional therapy of CD and UC quite commonly fails to bring satisfactory results, therefore an interest in new therapeutic options, that is, biological therapy, gene therapy, hematopoietic stem cell transplantation, and leucapheresis, has aroused recently. Biological therapy is focused on different stages of the inflammatory process. The fundamentals of biological strategy involve neutralization of pro-inflammatory cytokines, use of anti-inflammatory cytokines and inhibition of neutrophil adhesion. Biological therapy is a promising option because it enables to withdraw corticosteroids and immunosuppressive agents or to reduce their dose. Moreover, it shortens the hospital stay, allows to avoid surgical procedures, extends the remission period and improves patients' quality of life. Currently, 2 agents, infliximab and adalimumab, are registered for the biological therapy of CD in Poland.
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PMID:Biological therapy of inflammatory bowel disease. 1934 Nov 84

Interleukin 2 (IL-2)- and IL-10-knockout mice develop spontaneous colitis under conventional but not germ-free conditions, suggesting that commensal bacteria play an important role in the pathogenesis of colitis. However, interactions between commensal bacteria and colonic epithelial cells have not been fully investigated. We therefore assessed the ability of various commensal bacteria and probiotics to adhere to and invade colonic epithelial cells. Effects of the bacteria on production of proinflammatory cytokines were also measured. Commensal bacteria, including mucosal organisms isolated from ulcerative colitis (UC) patients, such as Fusobacterium varium, reported as a possible pathogen in UC, Bacteroides vulgatus, Escherichia coli and Clostridium clostridioforme, as well as their type strains and probiotics, were assessed for their ability to adhere to and invade colonic epithelial cells using two cell lines, SW-480 and HT-29. Our experiments employed co-incubation, a combination of scanning and transmission electron microscopy and recovery of bacteria from infected-cell lysates. F. varium and several other commensal bacteria, but not probiotics, adhered to colonic epithelial cells and invaded their cytoplasm. ELISA and real-time PCR revealed that the host cells, particularly those invaded by F. varium, showed significant increases in IL-8 and TNF-alpha concentrations in supernatants, with elevation of IL-8, TNF-alpha, MCP-1 and IL-6 mRNAs. Furthermore, IL-8 and TNF-alpha expression and nuclear phosphorylated NF-kappaB p65 expression could be immunohistochemically confirmed in inflamed epithelium with cryptitis or crypt abscess in UC patients. Certain commensal bacteria can invade colonic epithelial cells, activating early intracellular signalling systems to trigger host inflammatory reactions.
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PMID:Commensal bacteria can enter colonic epithelial cells and induce proinflammatory cytokine secretion: a possible pathogenic mechanism of ulcerative colitis. 1936 13

IL-24 is a member of the IL-10 family of cytokines. In this study, we investigated IL-24 expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for IL-24 expression in human colonic subepithelial myofibroblasts (SEMFs). IL-24 expression in the IBD mucosa was evaluated by immunohistochemical methods. IL-24 mRNA and protein expression was determined by real-time PCR and ELISA, respectively. AP-1 and C/EBP DNA-binding activity and IL-24 promoter activity were assessed by EMSA analysis and a reporter gene assay, respectively. IL-24 mRNA expression was significantly elevated in active lesions from patients who have ulcerative colitis and Crohn's disease. Colonic SEMFs were identified as a major source of IL-24 in the mucosa. IL-1beta, but not IL-17A, TNF-alpha, or IFN-gamma, significantly enhanced IL-24 mRNA and protein expression in isolated colonic SEMFs. The IL-1beta-induced IL-24 mRNA expression was mediated by the activation of the transcription factors, AP-1 and C/EBP-beta. Induction of IL-24 mRNA stabilization was also involved in the effects of IL-1beta. IL-24 induced JAK1/STAT-3 phosphorylation and SOCS3 expression in HT-29 colonic epithelial cells. IL-24 did not modulate the proliferation of HT-29 cells, but significantly increased the mRNA expression of membrane-bound mucins (MUC1, MUC3, and MUC4). IL-24 derived from colonic SEMFs acts on colonic epithelial cells to elicit JAK1/STAT-3 activation and the expression of SOCS3 and mucins, supporting their suppressive effects on mucosal inflammation in IBD.
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PMID:Expression of IL-24, an activator of the JAK1/STAT3/SOCS3 cascade, is enhanced in inflammatory bowel disease. 1953 21

Treatment failure occurs in up to 30% of patients treated with steroids for inflammatory diseases. The aim of this study was to explore the potential role of 21 cytokines in steroid-resistant inflammatory disease and to develop methods to restore steroid sensitivity through cytokine manipulation. The dexamethasone inhibition of lymphocyte proliferation assay correlates with the outcome of steroid therapy in ulcerative colitis (UC) and other inflammatory diseases. Using this assay, PBMC production of 21 cytokines, assayed by cytokine bead array, was correlated with percentage of suppression of proliferation by 10(-6) M dexamethasone (Imax) in 26 healthy volunteers. Effects of the addition of exogenous cytokines to induce steroid resistance in PBMCs from healthy volunteers and cytokine blockade to improve steroid sensitivity in PBMCs from patients with steroid-resistant UC were then explored. Production of IL-1alpha, IL-10, IL-17, IFN-gamma, G-CSF, GM-CSF, TNF-alpha, and IFN-inducible protein 10 (IP-10) correlated significantly with in vitro steroid sensitivity; however, only IL-2 and TNF-alpha reduced steroid sensitivity when added exogenously. Addition of IL-10 enhanced steroid suppression. Immunoneutralization or receptor blockade of IL-2, but not TNF-alpha, IFN-gamma, IL-4, IL-17, or IP-10 increased steroid sensitivity in cells from steroid-resistant UC patients. Neutralization of IL-10 reduced steroid sensitivity. Of the large panel of cytokines studied, IL-2 appears to have the greatest antagonistic effect on the antiproliferative effect of steroids. These data suggest that IL-2 inhibition in vivo may improve the response to steroids in steroid-resistant individuals.
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PMID:The effects of cytokines on suppression of lymphocyte proliferation by dexamethasone. 1954 27


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