Mucosa Of Ulcerative Colitis Patients Research Articles

Increased CD8+ intraepithelial lymphocyte infiltration and reduced surface area to volume ratio in the duodenum of patients with ulcerative colitis

Objective. Recent evidence suggests the involvement of the upper gastrointestinal tract in ulcerative colitis (UC). By conducting a prospective controlled study, we explored the immunological abnormalities in the duodenal mucosa of UC patients. Methods. Duodenal and colonic biopsies were collected from 24 corticosteroid-free UC patients and 21 controls. Colonization by Helicobacter pylori and positivity for anti-endomysial antibodies was an exclusion criteria. The severity of duodenal and colonic inflammation was determined by endoscopic and histologic scores. Morphometry was performed to measure the surface area to volume ratio (SV). Duodenal CD3+ and CD8+ intraepithelial lymphocytes (IELs) and lamina propria mononuclear cells (LPMCs) were detected by immunohistochemistry. Results. Fifteen UC patients and 14 controls were Helicobacter pylori and anti-endomysial antibody negative and were thus included in the study. Microscopic duodenitis was reported in 4 of the 15 UC patients (26.6%), and in none of the controls. A significantly higher number of CD3+ and CD8+ IELs and LPMCs was found in UC patients than in controls. A significant positive correlation between the percentage of both CD3+ and CD8+ IELs and disease activity was found in UC patients. SV was significantly reduced in UC patients compared to controls, and inversely correlated with the percentage of CD8+ IELs. Conclusions. The duodenum of UC patients is infiltrated by a higher number of CD8+ IELs which correlates with the degree of villous flattening and disease activity, but not with extent of the colonic lesions. Further studies are needed to clarify whether the duodenum is a target organ in UC.

W1213 Determination of 5-ASA and Its Derivatives in the Colonic Mucosa of Ulcerative Colitis Patients: A Surrogate Marker of Oxidative Damage?

W1213 Determination of 5-ASA and Its Derivatives in the Colonic Mucosa of Ulcerative Colitis Patients: A Surrogate Marker of Oxidative Damage?

Activation-Induced Cytidine Deaminase Links Between Inflammation and the Development of Colitis-Associated Colorectal Cancers

Activation-induced cytidine deaminase (AID) was originally identified as an inducer of somatic hypermutations in the immunoglobulin gene. We recently revealed that ectopic AID expression serves as a link between the cellular editing machinery and high mutation frequencies, leading to human cancer development. In the current study, we investigated whether AID might contribute to the development of colitis-associated colorectal cancers. The expression and regulation of AID in association with proinflammatory cytokine stimulation were investigated in cultured colonic cells. Genotoxic activity of AID in colonic cells was analyzed using retroviral system. Immunohistochemistry for AID was carried out on various human colonic tissues specimens. Tumor necrosis factor-alpha induced aberrant AID expression via IkappaB kinase-dependent nuclear factor (NF)-kappaB-signaling pathways in human colonic epithelial cells. Moreover, AID expression was also induced in response to the T helper cell 2-driven cytokines interleukin-4 and interleukin-13, which are activated in human inflammatory bowel disease. Aberrant activation of AID in colonic cells preferentially induced genetic mutations in the TP53 gene, whereas there were no nucleotide alterations of the APC gene. Immunohistochemistry revealed enhanced expression of endogenous AID protein not only in the inflamed colonic mucosa of ulcerative colitis patients but also in tumor lesions of colitis-associated colorectal cancers. Our findings indicate that proinflammatory cytokine-mediated aberrant expression of AID in colonic epithelial cells is a genotoxic factor linking inflammation, somatic mutations, and colorectal cancer development.

Omega-3 fatty acids exacerbate DSS-induced colitis through decreased adiponectin in colonic subepithelial myofibroblasts

Although the immunoregulatory effects of omega-3 fatty acid and adiponectin have been postulated, their role in intestinal inflammation is controversial. The aim of this study was to determine whether dietary fat intake influences activity of colonic inflammation through modulating this system. C57BL/6 mice received dextran sulfate sodium for induction of colitis. Mice were fed a control diet, omega-3 fat-rich diet, omega-6 fat-rich diet, or saturated fat-rich diet. Some mice were administered a peroxisome proliferator activated receptor-gamma; agonist, pioglitazone. Messenger RNA expression of adiponectin and its receptors were analyzed. Adiponectin expression in colonic mucosa of ulcerative colitis patients was also analyzed. The receptors for adiponectin were found to be ubiquitously expressed in epithelial cells, intraepithelial lymphocytes, lamina proprial mononuclear cells, and subepithelial myofibroblasts from colonic tissue, but adiponectin was only expressed in myofibroblasts. Induction of colitis significantly decreased the expression of adiponectin in colonic mucosa. The omega-3 fat diet group, but not the other fat diet groups, showed exacerbated colitis with a further decrease of adiponectin expression. Pioglitazone treatment ameliorated the level of decrease in adiponectin expression and improved colonic inflammation induced by the omega-3 fat-rich diet. In patients with ulcerative colitis, the expression level of adiponectin in colonic mucosa was also decreased compared with that in control mucosa. Adiponectin was found to be expressed in myofibroblasts. Adiponectin expression was significantly suppressed by induction of colitis, and aggravation of colitis after exposure to omega-3 fat may be due to a further decrease in the expression level of adiponectin.

T1219 Increased Expression of L-PGDS May Possibly Relate to Proinflammatory Roles in Colonic Mucosa of Ulcerative Colitis Patients

T1219 Increased Expression of L-PGDS May Possibly Relate to Proinflammatory Roles in Colonic Mucosa of Ulcerative Colitis Patients

Regulatory T cells in HIV infection: pathogenic or protective participants in the immune response?

Regulatory T cells in HIV infection: pathogenic or protective participants in the immune response?

Increased expression and activation of IL-12-induced Stat4 signaling in the mucosa of ulcerative colitis patients

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic inflammatory diseases with unsolved pathogenesis. Imbalanced Th1/Th2 may play a role in the sustained inflammation of IBD. In China, CD is rare but the incidence of UC has been rising steadily in the last two decades. We investigated the expression of IL-12 (p40) and IFN-γ, and the activational state of Stat4 signaling in mucosal tissues at the site of disease from 30 active UC patients in comparison with 30 healthy controls. RT-PCR analyses revealed increased mRNA expression of IL-12 (p40) but not IFN-γ in UC patients. Western blot analyses discovered, for the first time, increased levels of constitutive Stat4 in the cytoplasm and phosphorylated Stat4 in the nucleus of mucosal cells from UC patients. We conclude that a heightened, perhaps persistent, activational state of IL-12/Stat4, and/or IL-23/Stat4 signaling may be present in active Chinese UC patients, and possibly involved in chronic inflammation in UC.

Crucial pathophysiological role of CXCR2 in experimental ulcerative colitis in mice

Polymorphonuclear leukocyte infiltration and activation into colonic mucosa are believed to play a pivotal role in mediating tissue damage in human ulcerative colitis (UC). Ligands of human CXC chemokine receptor 1 and 2 (CXCR1/R2) are chemoattractants of PMN, and high levels were found in the mucosa of UC patients. To investigate the pathophysiological role played by CXCR2 in experimental UC, we induced chronic experimental colitis in WT and CXCR2(-/-) mice by two consecutive cycles of 4% dextran sulfate sodium administration in drinking water. In wild-type (WT) mice, the chronic relapsing of DSS-induced colitis was characterized by clinical signs and histopathological findings that closely resemble human disease. CXCR2(-/-) mice failed to show PMN infiltration into the mucosa and, consistently with a key role of PMN in mediating tissue damage in UC, showed limited signs of mucosal damage and reduced clinical symptoms. Our data demonstrate that CXCR2 plays a key pathophysiological role in experimental UC, suggesting that CXCR2 activation may represent a relevant pharmacological target for the design of novel pharmacological treatments in human UC.

Should ileal pouch–anal anastomosis include mucosectomy?

Debate exists as to the benefits of performing mucosectomy as part of pouch surgery for ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Whilst mucosectomy results in a more complete removal of diseased mucosa, this benefit may be at the price of poorer function. We examined these issues. Using Medline, Embase, Ovid and Cochrane database searches papers were identified relating to the outcome following pouch surgery with and without mucosectomy. Potential reasons for functional problems were investigated, as were rates of 'cuffitis', dysplasia, polyposis and cancer in the ileal pouch and anal canal. The available evidence suggests that performing a mucosectomy leads to a worse functional outcome. Meta-analysis suggested that nighttime seepage of stool and resting and squeeze pressure were worse after mucosectomy. The most likely reason for functional impairment following pouch surgery was the degree of anal manipulation. Mucosectomy does seem to confer benefit in terms of disease control but this benefit does not reach statistical significance. Stapled anastomosis avoiding mucosectomy is the approach of choice for ileal pouch anal anastomosis because this leads to superior functional outcome. Performing mucosectomy results in some clinical benefits in terms of lower rates of inflammation and dysplasia in the retained mucosa in UC patients and lower rates of cuff polyposis in FAP patients. However, on the basis of available evidence mucosectomy is only indicated in those cases where the patient is at a high risk of disease in the retained rectal cuff.

Study of Expression Patterns and Levels of Neurotrophins and Neurotrophin Receptors in Ulcerative Colitis

Neurotrophins may be involved in ulcerative colitis (UC). Yet, it is unclear whether if their effects should be blocked. In this study, the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and their receptors were examined by immunohistochemistry, ELISA, and RT-PCR. BDNF immunoreaction was detected in nerve structures in particular, and NGF immunoreaction was detected in lamina propria cells. Cellular NGF immunoreaction was generally observed to be higher in the mucosa of UC patients than in the controls. In addition, UC patients demonstrated significantly higher p75 immunoreaction (P = 0.010) in lamina propria cells. The controls expressed significantly higher BDNF immunoreaction in the nerve structures than did UC patients (P = 0.000). However, the UC group showed marked interindividual variation in expression of neurotrophins and neurotrophin receptors. This included variation at the mRNA level for NGF. Differences with the controls were most pronounced in UC specimens demonstrating great infiltration of inflammatory cells and marked tissue derangement. Corticosteroid treatment seemed to affect neurotrophin production in lamina propria cells but not in nerve structures. These observations demonstrate that up-regulation and down-regulation of neurotrophins occur in different structural components in response to the disease process. Massive inflammation seemed to be correlated with decreased neurotrophin immunoreaction in nerve structures, but there was a tendency toward increased neurotrophin production in lamina propria cells. Our study shows that UC patients are not a uniform group in their expression of neurotrophins, a fact that should be considered when discussing therapeutic interventions.

Apoptosis resistance in ulcerative colitis: High expression of decoy receptors by lamina propria T cells

Intestinal mucosa is constantly exposed to normal environmental antigens. A significant number of intestinal mucosal T cells are being deleted through apoptosis. In contrast, T cells from inflamed mucosa of ulcerative colitis patients did not undergo apoptosis. In this study, we determined whether the apoptosis of normal mucosal T cells was induced by antigen receptor stimulation and further determined pathways that mediated the apoptosis. Freshly isolated lamina propria T cells were stimulated with CD3 mAb and apoptosis was determined by Annexin V staining. Normal mucosal T cells underwent apoptosis upon CD3 mAb stimulation whereas the T cells from inflamed mucosa did not. The apoptosis in normal T cells was blocked by TRAIL-R1:Fc and an inhibiting CD95 antibody. Interestingly, decoy receptor (DcR)1, DcR2, and DcR3 that compete with death receptor (DR)4/5 and CD95 were highly expressed by the T cells from inflamed mucosa, but much lower by T cells from normal mucosa. Our data suggest that normal mucosal T cells are constantly deleted in response to environmental antigens mediated through DR4/5 and CD95 pathways and mucosal T cells from ulcerative colitis resist to undergoing apoptosis due to highly expression of DcR1, DcR2, and DcR3.

Differential expression of toll-like receptor 3 and 5 in ileal pouch mucosa of ulcerative colitis patients

The pathogenesis of pouchitis, major complication after restorative proctocolectomy, and ileal J pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC) is still unclear. Changes in intraluminal bacterial colonization and correlated changes of pouch mucosa are thought to play an important role. Toll-like receptors (TLRs) as part of the innate immune system are capable of recognizing bacterial antigens. Their activation can lead to secretion of proinflammatory mediators. In this study, TLR2, 3, 4, and 5 expression profiles in the pouch mucosa of patients with UC and IPAA were analyzed and correlated with pouchitis. Clinical symptoms, endoscopy, and histology were assessed in 35 patients using the Heidelberg Pouchitis Activity Score to classify patients as either having pouchitis or not. TLR mRNA expression in normal ileal mucosa and pouch mucosa was investigated by performing semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The results of RT-PCR were associated with the pouchitis score. In the analysis of all patients, TLR3 expression was decreased significantly whereas TLR5 expression was increased significantly in pouch mucosa compared to normal ileal mucosa (p-values 0.0076 and 0.016, respectively). A more detailed analysis upon dividing the patients into patients with and without pouchitis showed decreased TLR3 expression in the pouch mucosa only of patients without pouchitis (p-value=0.0067). TLR5 expression was increased in the pouch mucosa only of patients with pouchitis (p-value=0.023). No differences in TLR2 and 4 expression were found in either group. Differential expression of TLR3 and 5 suggests bacterial involvement in the pathogenesis of pouchitis in patients with UC.

The Expression Patterns of Toll-Like Receptors in the Ileal Pouch Mucosa of Postoperative Ulcerative Colitis Patients

The aim of this study was to evaluate the expression pattern of Toll-like receptors (TLRs) in the pouch mucosa of ulcerative colitis patients in comparison with that in the ileum mucosa of noninflammatory bowel disease patients. Pouch mucosal biopsy specimens were collected from postoperative patients who had undergone surgery for ulcerative colitis. Normal ileum specimens were collected from colon cancer patients. The specimens were assessed by immunofluorescence histochemistry using TLR2, TLR3, TLR4, and TLR5 polyclonal antibodies. The normal ileal mucosa constitutively expressed TLR3 and TLR5, whereas TLR2 and TLR4 were barely detectable. In the mucosa of active pouchitis, TLR2 and TLR4 was strongly upregulated, and TLR4 was upregulated even in a noninflamed pouch. No TLR3 or TLR5 expression was detectable. These data suggest that pouchitis may be associated with distinctive changes in selective TLR expression in the pouch mucosa, and that TLR4 alterations in the innate response system may contribute to the pathogenesis of these disorders in particular.

Infliximab Results in Reduction of Inflammation and Inflammatory Markers in the Mucosa of Ulcerative Colitis Patients

Infliximab Results in Reduction of Inflammation and Inflammatory Markers in the Mucosa of Ulcerative Colitis Patients

A high degree of aneuploidy, loss of p53 gene, and low soluble p53 protein serum levels are detected in ulcerative colitis patients.

The causes for the increased risk of colorectal cancer associated with ulcerative colitis have not been fully defined. Colonic tissue of ulcerative colitis patients was examined for changes in chromosome-17-centromere copy number, loss of the p53 gene, and alterations in serum levels of the 53-kDa protein. This study was performed under the assumption that these molecular events correlate with ulcerative colitis status and duration. Ulcerative colitis patients (n = 42) and healthy controls (n = 37) participated in the study. All participants were histopathologically and medically diagnosed. The stage of ulcerative colitis patients was stratified according to increasing risk factors for the development of colorectal cancer: left-sided colitis, pancolitis, sclerosing cholangitis, and dysplasia-associated lesions or masses. Changes in centromere number of chromosome 17 alone or in association with changes in copy number of the p53 gene were analyzed in colon tissue biopsies by fluorescence in situ hybridization. Serum p53 level was determined in blood samples by immunoprecipitation followed by separation using high-pressure liquid chromatography. Changes in chromosome 17 and p53 copy number and lower levels of serum p53 protein in ulcerative colitis patients directly correlated with colorectal cancer risk factors. All values significantly differed from controls. Significant direct correlations were obtained for ulcerative colitis disease duration, levels of p53 in the serum, and extent of aneuploidy. We demonstrate that in the colonic mucosa of ulcerative colitis patients, high levels of genomic instability, changes in p53 gene copy number, and lower levels of p53 in the serum directly correlate with the extent of disease duration and increased risk factors for colorectal cancer. Any of the measurements described herein can provide an acceptable prognostic tool in the assessment of colorectal cancer risk in ulcerative colitis patients.

Expression of Th1/Th2 cytokines in intestinal mucosa of ulcerative colitis

AIM: To investigate the effects of the expression of Th1/ Th2 cytokines in intestinal mucosa with ulcerative colitis. METHODS: Thirty patients (24 males, 6 females, age 18-79 years) with severe ulcerative colitis (UC) were examined by colonoscope, the diagnosis was confirmed by histological method. Bacterial infection was excluded through consecutive stool cultures twice. And ameba, schistosomiasis, gastroenterological cancer and endocrine diseases were also excluded. Ulcerative colitis was found in omni-colon (n =15) , sigmoid (n =9), rectum (n =6), respectively. Its clinical categories included relapse (n =20), persistent (n =7) and initial (n =3). They were treated by Sulphasalazine (SASP) and glucocorticoid after histological diagnosis. Eight weeks later, they were re-examined by colonoscope. The expression of cytokines in the intestinal mucosa of UC patients were detected by a semi-quantitative assay, reverse transcriptionpolymerase chain reaction(RT-PCR) before and after treatment respectively.

Is routine pouch surveillance for dysplasia indicated for ileoanal pouches?

Isolated accounts of neoplastic pouch transformation suggest the need to perform routine ileoanal pouch surveillance with biopsy. These reports imply a model of dysplasia to cancer transformation of the pouch mucosa. More recent reports studying "high risk" ulcerative colitis patients concluded that the development of pouch dysplasia is indeed a rare event. This study was designed to evaluate our institutional incidence of dysplasia in ileoanal pouch during long-term follow-up. A prospective database of all patients undergoing ileoanal pouch construction (n = 767) was queried for all patients undergoing pouch biopsy between 1983 and 2001. All patients with ulcerative colitis who underwent pouch biopsy were included. This excluded patients with Crohn's disease, indeterminate colitis, and familial adenomatous polyposis. Pathology reports were reviewed for histologic evidence of inflammation, atypia, metaplasia, dysplasia, or cancer. Patient age at biopsy, pouch age at time of biopsy, and pathology were analyzed. The ileoanal pouches of 160 patients were surveyed with biopsies a total of 222 times. The average length of follow-up from pouch construction to time of surveillance and biopsy was 8.4 +/- 4.6 years. There were 83 patients (52 percent) whose pouches were older than 10 years (mean, 12.7 +/- 2) at time of surveillance. With over 1,800 pouch-years of surveillance, only 1 patient had focal, low-grade dysplasia in the pouch. This patient demonstrated no evidence of dysplasia on further surveillance. Even with long-term follow-up of ileoanal pouch patients, there is little evidence to support routine biopsy of the ileal mucosa in ulcerative colitis patients.

Early changes of ileoanal pouch mucosa in patients with ulcerative colitis

Following closure of the protective ileostomy the mucosa of ileoanal pouches undergoes characteristic changes, which are thought to be caused by the new luminal environment Conventional histopathology and immunohistochemical markers were compared in serial pouch biopsies from patients with ulcerative colitis (UC) in the early period of function. Biopsy specimens were obtained from nine patients during ileostomy closure, 24 h after the first bowel action, then 6 days, 6 weeks and 3 months postoperatively. Cryostat sections were stained with haematoxylin and eosin (H&E) for assessment of mucosal inflammation and morphometry, and for lymphocyte subtypes (CD3, CD4, CD8), macrophages (CD68), common leucocyte antigen (CD45), and HLA-DR, using a three-stage immunoperoxidase reaction. Within 5 days of pouch function the index for mucosal atrophy (villous height/total mucosal thickness ratio) decreased significantly from a median (range) of 0.66 (0.39-0.69) to 0.52 (0.37-0.61)(P = 0.02). Intraepithelial lymphocyte counts diminished from 10.1 (5.6-21.1) to 7.0 (2.2-8.2)(P = 0.007) per 100 epithelial cells and remained so. In the lamina propria, apart from a transient increase in CD3 positive cells at 5 days (from 92.7 (58-165) to 100.5 (57-234) per unit area; P = 0.038), no significant changes were observed. H&E grading and HLA-DR expression remained unchanged. While there was no significant change in mucosal morphology and mucosal leucocyte subpopulations after 24 h of pouch function, the ileal pouch mucosa in UC patients had responded significantly within 5 days. Further studies into cell function and signalling are required.

Telomere shortening in the colonic mucosa of patients with ulcerative colitis.

Telomere length in human somatic cells gradually decreases with the number of cell divisions and is regarded as a marker of somatic cell turnover. Mucosal cells of the affected colon show rapid turnover in individuals with active ulcerative colitis (UC). Telomere length was determined by Southern blot analysis of terminal restriction fragments (TRFs) from the colonic mucosa of 17 patients with UC in remission, two of whom showed dysplasia, and 17 control subjects without colitis. For each individual, mean TRF length was compared between rectal mucosa and unaffected cecal mucosa. The mean TRF length of the rectal mucosa was significantly less than that of cecal mucosa in UC patients (7.87 +/- 0.36kb versus 8.77 +/- 0.21 kb; P = 0.0015, Wilcoxon signed rank test), whereas no significant difference was detected in the control subjects. The extent of telomere shortening was 10.6 +/- 3.35% in UC patients, compared with 0.8 +/- 0.64% in noncolitis controls (P = 0.0024, Mann-Whitney U-test). Four UC patients, two of whom had dysplasia, showed telomere shortening of more than 20% in the rectal mucosa. These observations suggest that telomere shortening in the colonic mucosa of individuals with UC may represent the history of mucosal inflammation during disease of long duration, and that it may contribute to aneuploidy in UC.

Activated CD4+ and CDS+ Cells in the Colonic Mucosa of Ulcerative Colitis Patients: Their Relationship to HLA-DR Antigen Expression on the Colonic Epithelium and Serum Soluble CD25 Levels

This study was performed to clarify the relationship between activated (HLA-DR-expressing) CD4+ and CD8+ cells in the colonic lamina propria of ulcerative colitis and other immunological factors, i.e., epithelial DR expression, serum soluble CD25 levels, and colonic mucosal CD25+ cells. The frequency of epithelial DR expression was positively correlated with the numbers of CD4+ and CD8+ cells. The percentages activated CD4+/CD4+ cells were higher in mucosae with DR- epithelium than in mucosae with DR+ epithelium. The serum soluble CD25 levels were increased in ulcerative colitis, and there was an inverse correlation between these levels and the relative number of activated CD4+ cells in untreated active disease. These results suggest that interactions among mucosal CD4+ cells, colonic epithelium, and serum soluble CD25 might play an important role in the pathogenesis of ulcerative colitis.