Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0010346 (Crohn's disease)
 21,615 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor-alpha, a proinflammatory cytokine, might have an important role(s) in initiating, modifying, and/or sustaining chronic inflammatory processes such as those that characterize Crohn's disease, an inflammatory bowel disease of unknown etiology. We used an immunogold ultrastructural morphometric approach to localize tumor necrosis factor-alpha in colonic Crohn's disease biopsies. Tumor necrosis factor-alpha was present in seven cell types (fibroblasts, eosinophils, mast cells, macrophages, colonic epithelial absorptive cells, Paneth cells, neutrophils). Tumor necrosis factor-alpha-containing subcellular organelles included lipid bodies (fibroblasts, eosinophils, macrophages, mast cells, colonic epithelial cells, neutrophils), secretory granules (eosinophils, Paneth cells), phagolysosomes (macrophages, colonic epithelial cells), and Golgi structures and vesicle membranes (neutrophils). A gradient of extracellular tumor necrosis factor-alpha immunoreactivity surrounded eosinophils, mast cells, and macrophages. P values of gold counts/microns2 were significant for all cells, organelles, and extracellular spaces measured, and all positive structures significantly exceeded the background labeling density/microns2. Specificity controls (normal rabbit serum, tumor necrosis factor-alpha-absorbed primary antibody) either failed to label these sites or gave markedly reduced specific tumor necrosis factor-alpha labeling, respectively. These findings represent the first ultrastructural localization of the subcellular sites of TNF-alpha in vivo in seven cell lineages in human colonic tissues.
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PMID:Ultrastructural immunogold localization of subcellular sites of TNF-alpha in colonic Crohn's disease. 766 84

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases of unknown etiology. However, there is circumstantial evidence that immune mechanisms play an important role in the pathogenesis of the intestinal lesion, and cytokines produced by lymphoid cells may be critical for the extraintestinal sequelae of the disease. In both Crohn's disease and ulcerative colitis, activation of macrophages seems to be a key feature. Increased production of the macrophage derived cytokines TNF-alpha, IL-1 and IL-6 have been reported in both diseases. Additionally in Crohn's disease, large numbers of activated T lymphocytes can be detected in the lamina propria and the T lymphocyte derived cytokines IL-2 and IFN-gamma are secreted by a higher number of lamina propria T lymphocytes in active Crohn's disease. However, this is not the case in ulcerative colitis. The increased number of activated T lymphocytes secreting IFN-gamma may be responsible for granuloma formation in Crohn's disease, as well as for MHC class II antigen expression on colonic epithelial cells. Lamina propria T lymphocytes seem to have lost their physiological unresponsiveness to several microbial antigens. All these observations suggest that Crohn's disease may be caused by hyperreaction of the local cellular immune system to numerous microbial and nutritional antigens normally present in the intestine. The factor inducing this immune dysregulation remains unknown. Cell-mediated immunity seems to be less important in ulcerative colitis, as activated T lymphocytes are only sparse within the inflamed mucosa, and the T lymphocyte derived cytokines IL-2 and IFN-gamma cannot be detected in the gut lesion or in the serum.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immune mechanisms in chronic inflammatory bowel disease. 810 3

The local release of inflammatory mediators are intricately linked with initiation and propagation of the inflammatory reaction in ulcerative colitis (UC) and Crohn's disease. We have used immunohistochemical staining of colonic biopsies to determine the cell of origin and the location of the cells which synthesize of TNF-alpha and IL-1 beta in patients with UC and Crohn's colitis. Patients were chosen from children aged 7-16 years, who had UC or Crohn's diagnosed following review of colonic biopsies taken during colonoscopy. The patients reviewed had not received treatment for inflammatory bowel disease. Paraffin embedded colonic biopsies were sectioned, deparaffinized, and stained with mouse monoclonal IgG antibodies directed against human recombinant TNF-alpha and IL-1 beta. The colonic lamina propria of all biopsies from patients with UC or Crohn's colitis was expanded with a mixed mononuclear, polymorphonuclear, lymphocytic, and plasmacytic infiltrate. Mononuclear cells distributed throughout the interstitium, stained prominently for both TNF-alpha and IL-1 beta. Plasmacytes, polymorphonuclear leukocytes, small lymphocytes, and foamy macrophages did not stain for either TNF-alpha or IL-1 beta. Transmigrating mononuclear cells in crypt epithelium also stained brightly for both TNF-alpha and IL-1 beta. Colonic epithelial cells did not stain for either TNF-alpha or IL-1 beta.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Tumor necrosis factor and IL-1 beta expression in pediatric patients with inflammatory bowel disease. 849 48

In 153 patients with IBD, 64 with Crohn's disease (CD), and 89 with ulcerative colitis (UC), as well as in 54 healthy controls (HC), the frequencies of four known di-allelic polymorphisms in the genes for TNF-alpha and lymphotoxin alpha (LTalpha) were investigated. In the Dutch population, the alleles of these four polymorphisms are present in only five combinations, called TNF haplotypes: TNF-C, -E, -H, -I, -P. Furthermore, the relation with the presence of perinuclear anti-neutrophil cytoplasmic autoantibodies (P-ANCA) was studied. A small, but statistically significant, association between the polymorphism at position -308 in the promoter region of the TNF-alpha gene and UC was found. The frequency of the uncommon TNF-alpha -308 allele 2 was found to be decreased in patients with UC compared with HC (allele frequency of allele 2 in UC patients 0-15 versus 0.25 in HC, P=0.044). No significant differences in distribution of the TNF haplotypes were found between IBD patients and HC, although there was a tendency towards a higher frequency of the TNF-C haplotype in UC patients compared with controls (haplotype frequency 22% versus 13%; P=0.19). No statistically significant differences in distribution of the TNF haplotypes were observed between P-ANCA-positive and P-ANCA-negative UC patients. The strength of the associations indicates that TNF genes are not markers for the predisposition to suffer from IBD. They may, however, be markers of subsets of patients with UC and CD.
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PMID:Distribution of four polymorphisms in the tumour necrosis factor (TNF) genes in patients with inflammatory bowel disease (IBD). 860 36

Activated lamina propria T cells responding to luminal Ags are thought to be important in celiac disease and Crohn's disease, and T cells responding to foreign MHC products are also important in intestinal graft-vs-host disease and intestinal transplant rejection. However, the mechanism(s) by which T cells mediate damage in the gut is not known. We have previously shown that activation of lamina propria T cells by PWM in explant cultures of second trimester human small intestine produces severe tissue injury, with epithelial cell shedding and loss of villi. In this study, we have investigated the role of matrix metalloproteinases in this system. Organ culture supernatants of explants stimulated with PWM showed a 3-fold increase in the concentration of interstitial collagenase and a 10-fold increase in stromelysin-1 compared with control explant culture supernatants. Tissue inhibitors of metalloproteinase-1 and -2 concentrations were unchanged. Increased metalloproteinase enzymatic activity was detected by gelatin and casein zymography. Western blotting revealed the active forms of interstitial collagenase and stromelysin-1 in PWM-stimulated culture supernatants. Up-regulation of mRNA for interstitial collagenase, stromelysin-1, and gelatinase-B was also seen. Nanomolar amounts of recombinant stromelysin-1 added directly to explants produced rapid severe tissue injury. PWM-induced mucosal injury was inhibited by a synthetic peptidomimetic inhibitor of matrix metalloproteinases. Mesenchymal cells isolated from the mucosa of human fetal small intestine produced increased amounts of interstitial collagenase, gelatinase A, and stromelysin-1 when stimulated with IL-1beta or TNF-alpha. These results suggest that T cell activation in the lamina propria results in increased production of matrix metalloproteinases, which by degrading the lamina propria matrix represent a major pathway by which T cells cause injury in the gut.
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PMID:A major role for matrix metalloproteinases in T cell injury in the gut. 902 93

Tumor necrosis factor-alpha is a potent cytokine, secreted primarily by activated monocytes and macrophages, that possesses a broad range of immunomodulating properties. Involvement of this cytokine has been validated in disease states such as arthritis and Crohn's disease and implicated in diverse neuroimmunological pathologies such as multiple sclerosis, Alzheimers and stroke. TNF-alpha is initially synthesized as a 26 kDa precursor molecule that is subsequently processed to the mature form by cleavage of the Ala76 Val77 bond. The 17 kDa carboxy-terminal protein is then secreted to function in a paracrine manner. The enzyme that processes precursor TNF-alpha has previously been identified as a microsomal metalloprotease called TNF-alpha converting enzyme (TACE). We have now purified and partially cloned the enzyme. TACE represents a novel target for therapeutic intervention in a variety of inflammatory and neuroimmunological diseases.
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PMID:Structural features and biochemical properties of TNF-alpha converting enzyme (TACE). 904 3

Treatment of perianal inflammatory lesions in Crohn's disease (CD) is unsatisfactory and novel treatment modalities are pursued. We have recently reported a good clinical effect of hyperbaric oxygen (HBO) treatment in perianal CD. In the present study, seven patients with perianal CD were subjected to daily sessions of HBO in a multiplace hyperbaric chamber. Each patient received a total of 20 sessions during a time period of 1 month, and IL-1, IL-6, and TNF-alpha measurements were done several times during the initial sessions and after completing therapy. Pretreatment cytokine levels were elevated in patients compared to age-matched 10 normal controls. During the first 7 days of treatment, IL-1, IL-6, and TNF-alpha levels in supernatants of LPS-stimulated monocytes derived from patients' peripheral blood were decreased compared to pretreatment levels. Parallel measurements of serum IL-1 levels revealed an initial elevation and thereafter decreased levels, which remained low throughout the first week of HBO treatment. After completion of therapy, cytokine levels increased to pretreatment values. We conclude that alterations in secretion of IL-1, IL-6, and TNF-alpha may be related to the good clinical effect of HBO treatment in CD patients with perianal disease.
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PMID:Modification of in vivo and in vitro TNF-alpha, IL-1, and IL-6 secretion by circulating monocytes during hyperbaric oxygen treatment in patients with perianal Crohn's disease. 908 91

Inflammatory mediator release is one of the body's responses to tissue injury and inflammation. These mediators, such as interleukin-1 beta (I1-1 beta), tumor necrosis factor (TNF-alpha), and products of arachidonic acid metabolism, are themselves proinflammatory. Purified human monocytes stimulated in vitro with E. coli-derived lipopolysaccharide (LPS) will release these key cytokines along with various other eicosanoid mediators. Monocytes incubated with LPS and the prostaglandin E-1 analog, misoprostol, released significantly lower levels of cytokines compared to monocytes incubated with LPS alone. Eicosanoid release was also affected by misoprostol. SC-46275, a more potent mucosal protective PGE1 analog, also altered the release of cytokines and eicosanoids from human monocytes. However SC-46275 inhibited I1-1 beta release with an IC50 value of 9 microM compared to 75 microM for misoprostol. SC-46275 and misoprostol both inhibited TNF-alpha release. These data suggest there is a potential immunomodulatory role for prostaglandin analogs in the therapeutic treatment of inflammatory diseases such as ulcerative colitis, Crohn's disease, and autoimmune inflammatory diseases of the central nervous system.
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PMID:The prostaglandin analogs, misoprostol and SC-46275, potently inhibit cytokine release from activated human monocytes. 913 3

TNF-alpha is a proinflammatory cytokine involved in many inflammatory conditions such as Crohn's disease, rheumatoid arthritis, cachexia, AIDS, and multiple sclerosis (MS). TNF-alpha is produced mainly by cells of the macrophage lineage, which includes microglia in the central nervous system. Here, we describe a mechanism through which TNF-alpha is generated by microglia. We show that activated human T lymphocytes induce the microglial production of TNF-alpha, and that is attenuated by a functional blocking antibody to CD49d, the alpha chain of the VLA-4 integrin on T cells. We also report that interferonbeta-1b (IFNbeta-1b), a drug that alleviates symptoms in MS, downregulates the expression of CD49d and reduces TNF-alpha production, mechanisms which can help account for its efficacy in MS.
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PMID:Microglial production of TNF-alpha is induced by activated T lymphocytes. Involvement of VLA-4 and inhibition by interferonbeta-1b. 923 8

Antibodies to tumor necrosis factor (TNF)-alpha have been recently proposed as effective treatment for patients with Crohn's disease. Here, we analyze the functional role of TNF-alpha in a mouse model of chronic intestinal inflammation induced by the hapten reagent 2,4,6,-trinitrobenzene sulfonic acid (TNBS) that mimics some characteristics of Crohn's disease in humans. Macrophage-enriched lamina propria (LP) mononuclear cells from mice with TNBS-induced colitis produced 10-30-fold higher levels of TNF-alpha mRNA and protein than cells from control mice. When mice with chronic colitis were treated by intraperitoneal injection of antibodies to TNF-alpha, an improvement of both the clinical and histopathologic signs of disease was found. Isolated macrophage-enriched LP cells from anti-TNF-alpha-treated mice produced strikingly less pro-inflammatory cytokines such as interleukin (IL)-1 and IL-6 in cell culture. The predominant role of TNF-alpha in the mouse TNBS-induced colitis model was further underlined by the finding that striking colonic inflammation and lethal pancolitis was induced in TNF-alpha-transgenic mice upon TNBS treatment. Conversely, no significant TNBS-induced colitis could be induced in mice in which the TNF-alpha gene had been inactivated by homologous recombination. Complementation of TNF-alpha function in TNF-/- mice by the expression of a mouse TNF-alpha transgene was sufficient to reverse this effect. Taken together, the data provide direct evidence for a predominant role of TNF-alpha in a mouse model of chronic intestinal inflammation and encourage further clinical trials with antibodies to TNF-alpha for the treatment of patients with Crohn's disease.
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PMID:Predominant pathogenic role of tumor necrosis factor in experimental colitis in mice. 924 86


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