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)

The intestinal epithelial cell population is comprised of a dynamic continuum, ranging from undifferentiated, actively proliferating crypt cells, to mature absorptive villus enterocytes, lacking mitotic capacity. Under normal conditions, the constant loss of differentiated villus tip cells via apoptosis leads to a complete renewal of the epithelial cell population every few days. The physiological factors regulating enterocyte proliferation, maturation and apoptosis in health, as well as those that modulate these events in disease states remain largely unknown. It has been demonstrated in vitro that immature crypt cell proliferation is stimulated by factors such as TGF alpha and TNF alpha, whereas TFG beta and IFN gamma inhibit mitotic activity. Further studies showed that intestinal epithelial cells are able to produce and secrete several cytokines such as IL6, IL8, TNF alpha, TGF alpha and TGF beta, indicating the potential for autocrine and paracrine responses. A variety of immune mediated bowel disorders, including celiac disease, Crohn's disease and ulcerative colitis, are characterized by accelerated epithelial cell turnover and apoptosis, leading to altered crypt/villus morphology. There is increasing evidence that these changes, and the accompanying functional alterations of the bowel epithelium, are mediated by the cytokines released from infiltrating inflammatory cells, as well as from enterocytes themselves in an autocrine fashion.
 ...
PMID:Cytokine--intestinal epithelial cell interactions: implications for immune mediated bowel disorders. 955 84

Interleukin-8 (IL-8) is a peptide which induces not only chemotaxis of neutrophils but also the release of reactive oxygen metabolites from the neutrophils. There are few reports which clarify the relationships between IL-8 and mucosal infiltration of neutrophils or reactive oxygen metabolites produced by neutrophils in the colonic mucosa of ulcerative colitis (UC). Biopsy specimens of colonic mucosa obtained from 26 patients with active UC and 21 patients with inactive UC were studied in order to clarify the relationships among the inflammation factors in UC. Levels of IL-8 and myeloperoxidase in organ culture media of the biopsy specimens from active UC (measured by ELISA and EIA) were significantly higher than those from inactive UC and controls. Reactive oxygen metabolites of biopsy specimens in active UC (measured by luminol-dependent chemiluminescence) were also markedly increased compared to those in inactive UC and controls. The levels of IL-8 were closely correlated to luminol-dependent chemiluminescence or myeloperoxidase levels. However, the levels of IL-8 and myeloperoxidase did not correlate with the grades of activity on colonoendoscopic findings. These findings suggest that IL-8 may play a role in the pathophysiology of UC but it does not define the endoscopic activity grades of UC.
 ...
PMID:Correlations between interleukin-8, and myeloperoxidase or luminol-dependent chemiluminescence in inflamed mucosa of ulcerative colitis. 961 52

Inflammatory bowel disease (IBD) denotes chronic inflammatory disorders of gastrointestinal tract of unknown etiology that comprises 2 major groups: ulcerative colitis (UC) and Crohn's disease (CD). Disregulation of the intestinal immune system both at humoral and cellular level constitutes an important element in the multifactorial pathogenesis of IBD. The expression of pro-inflammatory cytokines, most notably IL-1, IL-6, TNF-alpha and chemokines (IL-8, ENA-78, MCP-1, RANTES) in intestinal mucosa from IBD patients is markedly enhanced, however, it is not always accompanied by increases in cytokines' serum levels. In IBD also significant changes occur in the tissue expression of immunoregulatory cytokines: increased levels of IL-2 mRNA and IFN-gamma mRNA, and decreased expression of IL-4 were found in affected intestinal mucosa. Chronic intestinal lesions of patients with Crohn's disease are associated with a Th1 type cytokine profile. The clinical effectiveness of anti-TNF-alpha antibodies and of IL-10 has been demonstrated in steroid-refractory Crohn's disease patients. The data demonstrating the role of cytokines in the pathogenesis of IBD should be carefully analyzed because of limitations imposed by the patient- and sample-related parameters. Further investigations will clarify the significance of the impairments in cytokine network for the initiation and progression of the IBD.
 ...
PMID:Cytokines in inflammatory bowel disease. 970 46

Expression of DAF (CD55) is enhanced on colonic epithelial cells of patients with ulcerative colitis (UC), and stool DAF concentrations are increased in patients with active disease. Cytokines are known to modulate DAF expression in various human cells, and lesions of UC reveal altered profiles of cytokine production. In this study, we evaluate the effects of various cytokines, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, and interferon-gamma (IFN-gamma), on the synthesis and kinetics of DAF protein in HT-29 human intestinal epithelial cells. Using flow cytometry and an ELISA, we found that HT-29 cells constitutively express DAF on the cell surface and spontaneously release DAF into the culture supernatant under standard culture conditions. When the culture supernatant was centrifuged at 100000g, nearly a half of DAF was precipitated, indicating that one half of the released DAF was present as a membrane-bound form and the other half as a soluble form. Analysis of the culture supernatant of biotin surface-labelled HT-29 cells suggested that the soluble form DAF was derived by secretion from within the cell or by cleavage from the cell surface. Among the cytokines, IL-4 markedly, and IL-1beta moderately, enhanced the expression and the release of DAF. Actinomycin D, cycloheximide, and brefeldin A inhibited the increase in DAF release induced by IL-4 and IL-1beta stimulation. These results suggest that DAF is released from intestinal epithelial cells in response to cytokine stimulation and that IL-4 and IL-1beta are possible cytokines involved in DAF release into the colonic lumen of patients with UC.
 ...
PMID:Cytokine-stimulated release of decay-accelerating factor (DAF;CD55) from HT-29 human intestinal epithelial cells. 973 66

To elucidate the possible role of proinflammatory cytokines in inflammatory bowel disease, the expression and localization of interleukin (IL) -6 and IL-8 mRNAs were examined in colonic biopsy specimens obtained from 10 patients with active ulcerative colitis (UC), 5 with inactive UC, 6 with Crohn's disease (CD), and 5 normal controls. In situ hybridization with digoxigenin-labeled probes and immunohistochemistry for both cytokines were performed. The IL-6 mRNA expression was enhanced in the inflamed mucosa in 4 of 6 CD patients, while that of UC patients stayed at baseline. In contrast, IL-8 mRNA expression was apparently augmented (P = 0.044) in 7 of 10 active UC and 3 of 6 CD patients (NS). The cell count positive for IL-8 mRNA per unit area was definitely increased in moderate/severe UC when compared to mild UC (53.1 +/- 14.4/mm2 vs 9.0 +/- 5.1/mm2, P = 0.028) according to the degree of inflammation. IL-6 mRNA positive cells in CD were preferentially located in deeper lamina propria than IL-8 mRNA positive cells in UC. Interestingly, IL-8 mRNA was expressed in the mucosal epithelial cells in one UC patient. The patients treated by corticosteroids tended to show suppressed expression of each mRNA, except one patient with intractable UC. Our data suggest enhanced expression of mucosal IL-6 mRNA in CD and of IL-8 mRNA in UC by infiltrating mononuclear cells, indicating the distinct participation of each cytokine in the pathogenesis of UC and CD. Moreover, intestinal epithelial cells in UC occasionally exhibit IL-8 mRNA.
 ...
PMID:Mucosal expression of interleukin-6 and interleukin-8 messenger RNA in ulcerative colitis and in Crohn's disease. 975 75

The pleiotropic cytokine leukemia inhibitory factor (LIF) possesses proinflammatory properties in common with tumor necrosis factor (TNF-alpha), interleukine (IL) -1 and -6, such as the induction of acute phase protein synthesis. LIF may have chemotactic activity through the induction of IL-8 production. LIF is produced by normal and tumoral cells and appears to facilitate in vivo rat colon carcinoma cells growth. Inflammatory bowel diseases, ulcerative colitis (UC) in particular, are histologically characterized by the infiltration of the colonic mucosa with activated neutrophils, macrophages and lymphocytes. Cytokines with their inflammatory as well as their regulatory activities may play a role in the perpetuation and possibly the initiation of inflammation in this disease and its local and/or systemic complications. Moreover, colorectal cancer is a late well identified complication in patients with long standing inflammatory bowel disease, UC in particular. Taken together, these results suggest that LIF could be involved in tumorigenic and/or metastatic processes of colorectal cells in UC patients. The aims of the present study was to quantify and to compare the colonic and systemic productions of LIF in UC patients. We showed for the first time in patients with UC, a high local production of LIF well correlated with IL-8 production. We also analyzed the effect of LIF on a human colon carcinoma cell line HT29. We demonstrated that LIF stimulated HT29 cell growth in a dose dependent-manner. These results suggest that LIF may play a critical role in the susceptibility of colonic host cells to tumor growth in patients with UC.
 ...
PMID:Leukemia inhibitory factor involvement in human ulcerative colitis and its potential role in malignant course. 988 4

Proinflammatory cytokines are believed to be involved in the pathogenesis of ulcerative colitis (UC). The aim of this study was to clarify the profiles of proinflammatory cytokine production in patients with UC in terms of disease intractability, endoscopic findings, and host response to lipopolysaccharide (LPS) stimulation. Colonic mucosal tissues were obtained from patients with active UC (n = 15, including 4 patients with intractable disease) and inactive UC (n = 7), non-inflammatory bowel disease (IBD) colitis (n = 11), and controls (n = 20). Organ culture was performed, and the amounts of four cytokines (described below) in the culture media were determined by enzyme-linked immunosorbent assay (ELISA). LPS stimulation enhanced interleukin (IL)-1beta, IL-8, and IL-6 production in colonic specimens from all groups, but enhanced tumor necrosis factor (TNF)-alpha production only in active UC specimens. Levels of IL-6, IL-8, and TNF-alpha were significantly higher in active UC than in non-IBD colitis, and the production of all three of these cytokines was correlated to the endoscopic grade of inflammation. The production of these cytokines was also significantly higher in patients with intractable disease receiving corticosteroids than in patients with non-intractable disease receiving corticosteroids. These results suggest that enhanced production of mucosal proinflammatory cytokines may be implicated in the pathogenesis of UC.
 ...
PMID:Mucosal proinflammatory cytokine production correlates with endoscopic activity of ulcerative colitis. 1020 29

Leukocytapheresis (LCAP) with a leukocyte removal filter column was administered for 45 patients with ulcerative colitis (UC). We evaluated changes in the leukocyte count and the differential percentages during LCAP. Cytokine production was assessed from each patient's peripheral mononuclear cells or monocytes. Flow cytometry was performed to assess the removal rates of activated cells and adhesion molecule positive cells by LCAP. Clinical improvement was recognized in 35 of 45 patients during intensive LCAP therapy, and it continued throughout maintenance therapy in 32 patients (71.1%). The leukocyte count was decreased to about 40% during the first 30 min, but it increased to approximately 170% at 20 min after the completion of LCAP. The concentration of tumor necrosis factor (TNF)alpha before LCAP in the effective group was higher than it was in either the ineffective group or the control group. Its level decreased to near normal range after LCAP. In the effective group, the concentrations of interleukin (IL)-1beta, IL-2, interferon (IFN)gamma, and IL-8 were near the normal upper limits before LCAP; however, they had decreased after LCAP. The concentration of IL-4 increased after LCAP. In the ineffective group, in contrast, the concentrations had been at or near normal before the initial LCAP treatment. Flow cytometry study revealed that LCAP could remove the activated cells and adhesion molecule positive cells more effectively. The clinical improvement and the changes observed before and after LCAP therapy suggest that LCAP is able to intervene in the causal mechanism(s) of UC.
 ...
PMID:Leukocytapheresis with leukocyte removal filter as new therapy for ulcerative colitis. 1022 39

Anecdotal reports suggest that smoking may be beneficial for patients with inflammatory bowel disease (IBD) as nicotine may act through inflammatory mediators within the colonic mucosa. Furthermore, there is increasing evidence that cytokines play a pathologic role in IBD. Our aim was to determine the effects of cigarette smoking on cytokine levels in the colonic mucosa of patients with and without IBD. Mucosal biopsies were obtained from 10 patients with Crohn's disease (CD), 10 with ulcerative colitis (UC), and 10 healthy controls. Five of 10 patients in each of the three groups were smokers and five were nonsmokers. Concentrations of interleukin (IL)-1beta, IL-2, IL-6, and IL-8 were determined using enzyme-linked immunosorbent assay (ELISA). Cytokine levels of smokers were compared with nonsmokers in each group and with controls. Results were analyzed using the Mann-Whitney test; significance was set at p<0.05. The concentration of IL-8 was significantly higher in healthy controls who smoke compared with nonsmokers and significantly reduced in smokers with CD compared with nonsmokers with CD. Moreover, concentrations of IL-1beta and IL-8 were significantly reduced in smokers with UC compared with nonsmokers with UC. Smokers had significantly elevated levels of IL-8 in the colonic mucosa. Smokers with IBD had a significant reduction in cytokine levels; specifically, IL-1beta and IL-8 for patients with UC and IL-8 for patients with CD. Further studies are warranted to determine if this reduction in cytokine levels is histologically and clinically significant.
 ...
PMID:The influence of cigarette smoking on cytokine levels in patients with inflammatory bowel disease. 1033 74

Our goal was to determine the effect of transdermal nicotine on cytokine and mucin gene transcription in ulcerative colitis (UC). Sixty-four nonsmoking patients with active UC were randomly assigned to transdermal nicotine (maximum dose 22 mg/day) or placebo for 4 weeks. Clinical assessment and colonic mucosal biopsies were obtained at entry and after 4 weeks. Inflammatory and immunoregulatory cytokines were assessed by qualitative reverse transcriptase-polymerase chain reaction (RT-PCR). Based on this initial screen. IL-8 mRNA levels were measured by RT-competitive PCR. MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, and MUC6 mRNA concentrations were measured by quantitative dot blot analysis. Cytokine mRNA expression, except for IL-8, was similar in all patients. IL-8 mRNA levels were significantly decreased in the colonic mucosa of nicotine-treated patients who improved (p = 0.04). IL-8 mRNA values were similar before and after treatment in nonresponding nicotine-treated patients and in all placebo-treated patients. Mucin gene expression was similar in all patient groups. Beneficial effects of transdermal nicotine in active UC may result from decrease of IL-8 expression at the transcriptional level. Transdermal nicotine has no effect on mucin gene transcription.
 ...
PMID:Transdermal nicotine decreases mucosal IL-8 expression but has no effect on mucin gene expression in ulcerative colitis. 1045 73


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