Mucosa In Ulcerative Colitis Research Articles

Fibrosis Mediators in the Colonic Mucosa of Acute and Healed Ulcerative Colitis

OBJECTIVES:A healed intestinal mucosa is the aim of therapy in acute ulcerative colitis (UC). Disruption of mucosal wound healing may lead to severe complications including intestinal fibrosis. This study examined mucosal gene expression in the healing process of acute UC with a special focus on known mediators of fibrosis.METHODS:Endoscopic biopsies from patients with acute, moderate to severe UC were analyzed with a quantitative polymerase chain reaction array for 84 genes involved in fibrosis pathways. All patients were treated with infliximab (anti– tumor necrosis factor). Biopsies were taken before therapy and when disease remission was reached, defined as a Mayo score of ≤2, with an endoscopic subscore of 0 or 1. A healthy control group was included. Immunostaining of matrix metallopeptidase 9 and smooth muscle actin was performed.RESULTS:Mucosal biopsies from acute UC (n = 28), remission UC (n = 28), and healthy controls (n = 13) were analyzed. Fibrosis and extracellular matrix-associated genes were upregulated in the endoscopically healed UC mucosa vs controls, with collagen type III alpha 1 chain, actin alpha 2, lysyl oxidase, TIMP metallopeptidase inhibitor 3, and caveolin 1 uniquely showing no overlap with acute disease. Pro- and antifibrotic mediators (interleukin [IL]13 receptor subunit alpha 2, IL1B, IL10, tumor necrosis factor, snail family transcriptional repressor 1, and C-C motif chemokine ligand 2) were upregulated in both acute and healed UC compared with controls. An attenuated pattern of the canonical transforming growth factor beta (TGFB) pathway was observed in acute UC and to a lesser extent in the healed mucosa, except for TGFB2, which was enhanced.DISCUSSION:The endoscopically healed mucosa of UC showed a persisting dysregulation of fibrosis-associated mediators compared with controls, including extracellular matrix remodeling, profibrotic cytokines, and TGFB signaling pathways.

Difference in the clinical characteristic and prognosis of colitis-associated cancer and sporadic neoplasia in ulcerative colitis patients

BackgroundAlthough various studies have been conducted on colitis-associated cancer (CAC), few have assessed the differences in the clinical and endoscopic features, treatment, and prognosis of CAC and sporadic neoplasia (SN) in the inflamed mucosa of ulcerative colitis (UC) patients. AimsTo compare the characteristics of CAC and SN within the previously or currently inflamed mucosa. MethodsBetween 1997 and 2017, we retrospectively analyzed the endoscopic chart data of 348 colonic lesions from 266 UC patients. Non-dysplastic lesions and lesions located outside the inflamed mucosa were excluded. The diagnosis of CAC or SN was confirmed by conventional histopathological and immunohistochemical evaluation of p53 and Ki67. ResultsIn total, 74 patients with CAC (97 lesions) and 46 with SN (58) were enrolled. The proportions of patients with a younger age of onset of UC, with chronic persistent UC, and with severe inflamed mucosa were significantly higher in the CAC group. In the SN group, no flat lesions were found, whereas 26% of the lesions in the CAC group were flat. Sixteen patients died during a median follow-up of 6.1 years (interquartile range (IQR) 1.8–11.1)in the CAC group, whereas 1 patient died during a median follow-up 3.2 years(IQR 1.4–4.6) in the SN group. Mortality from colorectal cancer was significantly higher (P = 0.015) in the CAC group (12/68; 17.6%) than in the SN group (1/44; 2.3%). The 5-year survival rate was 100% in the SN group and 97% in the CAC group for lesions located in the mucosa or submucosa. ConclusionRecognizing differences in the characteristics of CAC and SN within the inflamed mucosa is critical to avoid unnecessary total colectomy in patients with SN.

259 – Increased Bacteriophage Abundance and Loss of Viralbacterial Interactions in the Mucosa of Ulcerative Colitis: Key to Pathogenesis?

259 – Increased Bacteriophage Abundance and Loss of Viralbacterial Interactions in the Mucosa of Ulcerative Colitis: Key to Pathogenesis?

Integrated analysis of circRNAs and mRNAs expression profile revealed the involvement of hsa_circ_0007919 in the pathogenesis of ulcerative colitis.

Ulcerative colitis (UC) is characterized by chronic inflammation in the colon and epigenetic factors underlying the occurrence. Circular RNAs (circRNAs) have been under intensive focus due to the circular construct and gene-regulating functions. However, the changes and roles of circRNAs in UC remain unknown. Microarrays were used to detect the differentially expressed genes, and quantitative real-time PCR was used to identify the changes in UC. In silico analyses were performed to predict the functions of circRNAs and mRNAs. In vitro, epithelial cell lines were stimulated by pro-inflammation effectors to test the alterations in circRNAs. CircRNAs-microRNAs-mRNAs network clarified the potential mechanisms underlying circRNAs in UC. The binding site between hsa_circ_0007919 and miR-138 or let-7a was verified using dual-luciferase assay. A total of 264 significantly dysregulated circRNAs and 1869 differentially expressed mRNAs in inflamed mucosa were compared with the non-inflamed mucosa in UC. Hsa_circ_0004662 and hsa_circ_0007919 were altered largely in UC tissues. Hsa_circ_0007919 was reduced persistently after inflammatory treatments, and it was relevant to Mayo endoscopic subscores and the expression of tight junction molecules. Finally, hsa_circ_0007919 could harbor miR-138, and let-7a to regulate the targeted mRNAs EPC1 and VIPR1. Several circRNAs were differentially expressed in UC. Hsa_circ_0007919 is related to clinical characteristics and epithelial integrity by binding to hsa-let-7a, hsa-miR-138 to regulate the target genes. CircRNAs, especially hsa_circ_0007919, are associated with the pathogenesis and development of UC, with potential diagnostic and therapeutic implications.

Loss of RUNX3 Immunoreactivity in Non-Neoplastic Rectal Mucosa May Predict the Occurrence of Ulcerative Colitis-Associated Colorectal Cancer

Background/Aims: Runt-related transcription factor (RUNX) 3 is a tumor suppressor whose expression is reduced in non-neoplastic rectal mucosa of patients with ulcerative colitis (UC) with coexisting colitis-associated cancer (CAC). We aimed to evaluate RUNX3 utility as a predictive marker for CAC using immunohistochemistry (IHC) for non-neoplastic UC mucosa. Methods: We retrospectively compared the RUNX3 expression detected by IHC between non-neoplastic rectal biopsy specimens from 20 cases with invasive cancer (CAC group) and 20 cases selected from 138 patients without CAC (non-CAC group) that were treated during the same period (2006–2017) and were matched for sex, duration, extension, and age. We validated the results using tissue microarrays (TMA) of 44 operated cases with CAC. The RUNX3 expression level was determined by calculating the percentage of RUNX3-positive-cells. Results: The RUNX3 expression was lower in the CAC than that in the non-CAC group (35.6 vs. 70.7%, p = 0.03). For a cutoff value of 58%, the sensitivity and specificity for predicting CAC were 75.0 and 70.0% respectively. The immunostaining results for the TMA showed the same trend; 74% of cases with CAC were negative for the RUNX3 expression. Conclusion: RUNX3 immunostaining of non-neoplastic mucosa is useful for identifying UC patients at a high risk of developing CAC.

Soluble human Suppression of Tumorigenicity 2 is associated with endoscopic activity in patients with moderate-to-severe ulcerative colitis treated with golimumab.

Background:Suppressor of Tumorigenicity 2 (ST2) is an IL33 receptor detected in the mucosa and serum of ulcerative colitis (UC) patients. We evaluated soluble ST2 (sST2) as a surrogate biomarker of disease outcome and therapeutic response, in moderate-to-severe UC patients treated with golimumab.Methods:We conducted an open-label single-arm multicentre prospective study. At screening/baseline, week 6 (W6) and week 16 (W16), clinical and endoscopic activity (total Mayo score), histologic activity (Geboes index) and biomarkers were evaluated.Results:From 38 patients, 34 (89.5%) completed W6 and 29 (76.3%) completed W16. Mean age (±SD) was 34.6 ± 12.6 years; 55.9% were female. At W16, 62.1% achieved clinical response. Patients with endoscopic activity at W6 (n = 20) had higher baseline sST2 (median, 24.5 versus 18.7 ng/ml, p = 0.026) and no decrease from baseline (median change, 0.8 versus −2.7, p = 0.029). At W6, sST2 levels correlated with endoscopic activity (rs = 0.45, p = 0.007) but not with histological activity (rs = 0.25, p = 0.151). The best cut-offs for endoscopic activity were sST2 = 16.9 ng/ml (sensitivity = 85%; specificity = 71%) and faecal calprotectin (FC) = 353 μg/g (sensitivity = 90%, specificity = 67%). Patients with histological activity at W6 (n = 27) had higher baseline ST2 levels (median, 23.0 versus 13.7 ng/ml, p = 0.035). sST2 did not correlate with FC or serum C-reactive protein. FC levels correlated with histological activity and baseline FC were higher when Geboes ⩾3.1 at W6.Conclusions:sST2 may be a surrogate biomarker of UC activity and therapeutic response as it correlates with endoscopic and clinical activity at W6 of golimumab treatment, and subjects with endoscopic and histological activity at W6 had higher baseline ST2 levels.

Difference in Pathomechanism Between Crohn's Disease and Ulcerative Colitis Revealed by Colon Transcriptome.

We aim to identify the differences in colonic mucosal transcriptome between Crohn's disease (CD) and ulcerative colitis (UC) for a better understanding of the molecular pathology. Differentially expressed genes (DEG) in the colonic mucosa of CD and UC were identified with a global gene expression microarray dataset generated from the colon biopsies of CD and UC patients and normal controls. The DEGs were then processed to identify altered pathways and modularized DEGs and pathways. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis with an independent cohort of samples was performed to validate the microarray data. At the pathway level, virus infection and autoimmune pathways were upregulated in CD but not in UC when compared with controls. Some of the relevant DEGs (such as TAP1 and TAP2) were elevated in both CD and UC, with CD exhibiting more pronounced elevations. Gene expression levels in viral infection pathways were correlated with those of autoimmune pathways. In contrast, pattern recognition-mediated innate immune pathways (TLR4 and TLR2) were significantly elevated in UC but not in CD. Similar results were observed with an independent cohort by qRT-PCR. Our data support the hypothesis that viral infection induced autoimmunity may represent a pathomechanism for IBD, especially CD. However, pattern recognition-mediated innate immunity targeting microbiome may play a more important role in UC compared with CD. Our findings identified different intervention targets for CD and UC, which may lead to more effective treatments for IBD patients.

Mucosal adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG in the human colonic mucosa: A proof-of-concept study.

AIMTo investigate the adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG (LGG) in the colonic mucosa of healthy and ulcerative colitis (UC) patients, both in vivo and ex vivo in an organ culture model.METHODSFor the ex vivo experiment, a total of 98 patients (68 UC patients and 30 normal subjects) were included. Endoscopic biopsies were collected and incubated with and without LGG or LGG-conditioned media to evaluate the mucosal adhesion and anti-inflammatory effects [reduction of tumor necrosis factor alpha (TNFα) and interleukin (IL)-17 expression] of the bacteria, and extraction of DNA and RNA for quantification by real-time (RT)-PCR occurred after the incubation. A dose-response study was performed by incubating biopsies at “regular”, double and 5 times higher doses of LGG. For the in vivo experiment, a total of 42 patients (20 UC patients and 22 normal controls) were included. Biopsies were taken from the colons of normal subjects who consumed a commercial formulation of LGG for 7 d prior to the colonoscopy, and the adhesion of the bacteria to the colonic mucosa was evaluated by RT-PCR and compared with that of control biopsies from patients who did not consume the formulation. LGG adhesion and TNFα and IL-17 expression were compared between UC patients who consumed a regular or double dose of LGG supplementation prior to colonoscopy.RESULTSIn the ex vivo experiment, LGG showed consistent adhesion to the distal and proximal colon in normal subjects and UC patients, with a trend towards higher concentrations in the distal colon, and in UC patients, adhesion was similar in biopsies with active and quiescent inflammation. In addition, bioptic samples from UC patients incubated with LGG conditioned media (CM) showed reduced expression of TNFα and IL-17 compared with the corresponding expression in controls (P < 0.05). Incubation with a double dose of LGG increased mucosal adhesion and the anti-inflammatory effects (P < 0.05). In the in vivo experiment, LGG was detectable only in the colon of patients who consumed the LGG formulation, and bowel cleansing did not affect LGG adhesion. UC patients who consumed the double LGG dose had increased mucosal concentrations of the bacteria and reduced TNFα and IL-17 expression compared with patients who consumed the regular dose (48% and 40% reduction, respectively, P < 0.05).CONCLUSIONIn an ex vivo organ culture model, LGG showed consistent adhesion and anti-inflammatory effects. Colonization by LGG after consumption for a week was demonstrated in vivo in the human colon. Increasing the administered dose increased the adhesion and effectiveness of the bacteria. For the first time, we demonstrated that LGG effectively adheres to the colonic mucosa and exerts anti-inflammatory effects, both ex vivo and in vivo.

Importance of TLR9-IL23-IL17 axis in inflammatory bowel disease development: Gene expression profiling study

Background and aimsMucosal gene expression have not been fully enlightened in inflammatory bowel disease (IBD). Aim of this study was to define IL23A, IL17A, IL17F and TLR9 expression in different IBD phenotypes. MethodsEvaluation of mRNA levels was performed in paired non-inflamed and inflamed mucosal biopsies of newly diagnosed 50 Crohn's disease (CD) and 54 ulcerative colitis (UC) patients by quantitative real-time PCR analysis. ResultsIL17A and IL17F expression levels were significantly increased in inflamed IBD mucosa. Inflamed CD ileal and UC mucosa showed increased IL23A, while only inflamed CD ileal samples showed increased TLR9 mRNA level. Correlation between analysed mRNAs levels and endoscopic and clinical disease activity were found in UC, but only with clinical activity in CD. ConclusionBoth CD and UC presented expression of Th17-associated genes. Nevertheless, expression profiles between different disease forms varies which should be taken into account for future research and therapeutics strategies.

Colonic Inhibition of Phosphatase and Tensin Homolog Increases Colitogenic Bacteria, Causing Development of Colitis in Il10-/- Mice.

Phosphatase and tensin homolog (Pten) is capable of mediating microbe-induced immune responses in the gut. Thus, Pten deficiency in the intestine accelerates colitis development in Il10-/- mice. As some ambient pollutants inhibit Pten function and exposure to ambient pollutants may increase inflammatory bowel disease (IBD) incidence, it is of interest to examine how Pten inhibition could affect colitis development in genetically susceptible hosts. With human colonic mucosa biopsies from pediatric ulcerative colitis and non-IBD control subjects, we assessed the mRNA levels of the PTEN gene and the gene involved in IL10 responses. The data from the human tissues were corroborated by treating Il10-/-, Il10rb-/-, and wild-type C57BL/6 mice with Pten-specific inhibitor VO-OHpic. We evaluated the severity of mouse colitis by investigating the tissue histology and cytokine production. The gut microbiome was investigated by analyzing the 16S ribosomal RNA gene sequence with mouse fecal samples. PTEN and IL10RB mRNA levels were reduced in the human colonic mucosa of pediatric ulcerative colitis compared with non-IBD subjects. Intracolonic treatment of the Pten inhibitor induced colitis in Il10-/- mice, characterized by reduced body weight, marked colonic damage, and increased production of inflammatory cytokines, whereas Il10rb-/- and wild-type C57BL/6 mice treated with the inhibitor did not develop colitis. Pten inhibitor treatment changed the fecal microbiome, with increased abundance of colitogenic bacteria Bacteroides and Akkermansia in Il10-/- mice. Loss of Pten function increases the levels of colitogenic bacteria in the gut, thereby inducing deleterious colitis in an Il10-deficient condition.

Identification and analysis of key genes associated with ulcerative colitis based on DNA microarray data.

This study aimed to identify genes that may play a role in development of ulcerative colitis (UC) and gain insight into its pathogenesis.Gene expression profiling data, including samples collected from 13 early-stage UC (EUC), 8 advanced-stage UC (AUC), and 5 control subjects, were downloaded from the Gene Expression Omnibus database under the accession number of GSE9452. Differentially expressed genes (DEGs) were identified in EUC and AUC compared with controls. DEGs for EUC and AUC, as well as AUC-specific DEGs were subjected to pathway enrichment analysis. Random Walk with Restart (RWR) was used to identify DEGs that are critical in UC based on a protein-to-protein interaction (PPI) network and the inflammatory bowel disease (IBD) pathway downloaded from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. IL17 and transforming growth factor beta TGF-β) expression levels in colonic tissue from patients with UC and normal colonic mucosa from healthy adults were analyzed by immunohistochemistry (IHC).A total of 3511 and 911 DEGs were identified in AUC and EUC, respectively. The overlapping DEGs and the AUC-specific DEGs were both enriched in pathways related to immunity, such as antigen processing and presentation. AUC-specific DEGs were related to cell migration, such as ECM-receptor interaction. Following DEG prioritization, TLR4 and STAT1 were linked with EUC, AUC, and CD. The upregulated gene TGFB increased the number of Th17 cells, as verified by IHC. Furthermore, PIK3R1, CREBBP, and STAT1 were part of high-degree nodes in the PPI sub-network.The upregulated gene TGFB may regulate IL17 expression in UC. PIK3R1 may participate in immunity and CREBBP may interact with STAT1 in the development and progression of UC.

A Novel Topical PPARγ Agonist Induces PPARγ Activity in Ulcerative Colitis Mucosa and Prevents and Reverses Inflammation in Induced Colitis Models

Peroxisome proliferator-activated receptor-gamma (PPARγ) exerts anti-inflammatory effects and is therefore a potential target in ulcerative colitis (UC). A novel PPARγ agonist (AS002) developed for local action was evaluated ex vivo in biopsies from UC patients and in vivo in mice with low-grade dextran sodium sulfate (DSS)- and trinitrobenzene sulfonic acid (TNBS)-induced colitis. Colonic biopsies from UC patients (n = 18) and healthy controls (n = 6) were incubated with AS002 or rosiglitazone (positive control) to measure mRNA expression of the PPARγ-responsive gene ADIPOPHILIN and protein levels of UC-related cytokines (enzyme-linked immunosorbent assay). AS002 absorption was determined in the colonic mucosa of UC patients. DSS-colitis mice received PPARγ agonists or vehicle daily by intrarectal administration starting 2 days before induction of colitis (preventive) or from days 3 to 8 (curative). Myeloperoxidase (MPO) and cytokine levels in colonic mucosa were determined. In addition, AS002 effects were studied in TNBS colitis. AS002 displayed an absorption pattern of a lipophilic drug totally metabolized in the mucosa. AS002 and rosiglitazone increased ADIPOPHILIN mRNA expression (3-fold) and decreased TNF-α, IL-1β, and IL-13 levels in human UC biopsies. In DSS, in both preventive and curative treatment and in TNBS colitis, AS002 protected against macroscopic and histological damage and lowered MPO and TNF-α, IL-1β, and IL-13 levels. AS002 triggers anti-inflammatory PPARγ activity in the human colonic mucosa of UC patients and prevents and reverses colitis in mice. Our data suggest that AS002 has potential for topical maintenance treatment of UC, which warrants further studies in vivo in patients.

MicroRNA-31 and MicroRNA-155 Are Overexpressed in Ulcerative Colitis and Regulate IL-13 Signaling by Targeting Interleukin 13 Receptor α-1.

Interleukin-13 (IL-13) is an important Type 2 T helper (Th2) cytokine, controlling biological functions in epithelium and has been linked to asthma, atopic dermatitis and ulcerative colitis (UC). Interleukin-13 signals through IL-13 receptor α-1 (IL13RA1 (gene) and IL13Rα1 (protein)), a receptor that can be regulated by microRNAs (miRs). MicroRNAs are small non-coding single-stranded RNAs with a role in several pathologies. However, their relevance in the pathophysiology of UC, a chronic inflammatory condition of the colonic mucosa, is poorly characterised. Here, we determined the expression of IL13Rα1 in UC, its potential regulation by miRs and the subsequent effect on IL-13 signalling. Inflamed mucosa of UC patients showed decreased mRNA and protein expression of IL13RA1 when compared to healthy controls. We show that miR-31 and miR-155 are upregulated in inflamed UC mucosa and that both directly target the 3′ untranslated region of IL13RA1 mRNA. Transfection of miR-31 and miR-155 mimics reduced the expression of IL13RA1 mRNA and protein, and blocked IL-13-dependent phosphorylation of signal transducer and activator of transcription 6 (STAT6) in HT-29 cells, a gut epithelium cell line. Interleukin-13 activation of suppressor of cytokine signaling 1 (SOCS1) and eotaxin-3 (CCL26) expression was also diminished. MicroRNA-31/microRNA-155 mimics also downregulated IL13RA1 in ex vivo human inflamed UC biopsies. We propose that miR-31 and miR-155 have an important role in limiting IL-13 signalling in UC disease.

Ileal pouch of ulcerative colitis and familial adenomatous polyposis patients exhibit modulation of autophagy markers

Total retocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgery of choice for patients with ulcerative colitis (UC) that are refractory to clinical treatment. Pouchitis is one of the most common complications after this procedure. Defects in autophagy have been reported in inflammatory bowel diseases. However, there are no studies on the IP. Therefore, we studied markers for autophagy in the IP mucosa of UC and FAP patients comparing them to controls with a normal distal ileum. Sixteen patients with IP in “J” shape, asymptomatic and with endoscopically normal IP were evaluated. The control group consisted of eight patients with normal colonoscopy. There was a significant decrease in the transcriptional levels of ATG5, MAP1LC3A and BAX in the FAP group. There was also a decrease in the protein level of Beclin-1 in the UC and FAP compared to the control group. Although the LC3II levels by immunoblot were higher in the UC group, LC3/p62 co-localization were lower in the immunofluorescence analysis in the UC and FAP compared to the control group. Corroborating these results, there was an increase of p62 by immunoblot in the UC group. These findings indicated a modulation of macroautophagy markers in the IP, which may explain the mucosa inflammation predisposition.

Ileal Pouch of Ulcerative Colitis Patients Exhibit Impaired Autophagy

BACKGROUND: Total rectocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgery of choice for patients with ulcerative colitis (UC) that are refractory to clinical treatment and for familial adenomatous polyposis (FAP) with many rectal polyps. The main complication after this procedure is the pouch inflammation (pouchitis) that can affect up to 45 percent of patients who are submitted to IPAA for UC, and only five percent of the FAP patients who undergo the same procedure. Previous studies have shown increased pro-inflammatory cytokines in the ileal pouch (IP) mucosa of UC patients, even in the absence of clinical, endoscopic and histological inflammation. Autophagy is an evolutionarily conserved catabolic pathway that consists of selective degradation of cellular components and a homeostatic mechanism that protects cells exposed to stress situations (toxins, starvation), and defects in this pathway have been reported in inflammatory bowel diseases. However, there are no studies on the IP. Therefore, we studied markers for autophagy in the IP mucosa of UC and FAP patients comparing them to controls with a normal distal ileum. METHODS: Sixteen patients with IP in "J" shape, asymptomatic and with endoscopically normal mucosa were evaluated. The control group consisted of eight patients with normal colonoscopy. Gene expression was analyzed by qPCR and protein levels by immunoblotting and immunofluorescence. This study was approved by the Ethics Committee of the University of Campinas and was performed in accordance with the Declaration of Helsinki. All results were reported as means ± SEM. Data were analyzed by non-parametric Test, comparing all groups. The level of significance was set at P<0.05. RESULTS: There was a significant decrease in the transcriptional levels of ATG5, MAP1LC3A and BAX in the FAP group (P<0.05). There was also a decrease in the protein level of Beclin-1 in the UC and FAP compared to the control group (P<0.05). Although the LC3II levels by immunoblot were higher in the UC group, total LC3 and LC3/p62 co-localization were lower in the immunofluorescence analysis in the UC and FAP compared to the control group (P<0.05). Corroborating to these results, there was an increase of p62 by immunoblot in the UC group, compared to controls (P<0.05). CONCLUSION(S): These results indicate impaired macroautophagy mechanism in the IP. In FAP, decreased autophagy may be related to impaired apoptosis, otherwise in UC, may be mainly due to increased Toll-Like Receptors (TLR) activation. These findings may explain the inflammation predisposition, mainly in the IP mucosa of UC patients. Acknowledgments: We thank FAPESP (São Paulo Research Foundation) for financial support. Negreiros LMV (co-author) received scholarship from FAPESP. We are grateful to Prof. Tristan Torriani for English grammar revision. We thank Francesca Ramos and José Diego Botezelli for technical assistance and the staff of the Life Sciences Core Facility (LaCTAD) from State University of Campinas (UNICAMP), for the Cell Biology analysis.

Gut-associated Lymphoid Tissue (GALT) Carcinoma in Ulcerative Colitis.

In ulcerative colitis (UC), the majority of colorectal carcinomas (CRC) arise in the vast colorectal mucosal domain built with mucus-producing goblet cells and columnar cells. Conversely, CRC in UC rarely evolve in the tiny, spotty gut-associated lymphoid tissue (GALT) mucosal domain. Here we review the four reported cases of colonic carcinoma developing in GALT mucosa in UC, searching for possible precursor lesions connected with the evolution of these tumours. The clinical history, age, gender, endoscopic descriptions, and the pathology (localization, gross and histological descriptions of the luminal surface) of the four UC-GALT carcinomas reported in the literature were reviewed. The luminal surface in three out of the four carcinomas revealed conventional (tubular/villous) adenomas or high-grade dysplasia. All four UC-GALT-carcinomas were detected at an early stage (T1N0). GALT carcinomas do occur, albeit infrequently, in patients with UC. The finding that three out of the four GALT carcinomas on record were covered by conventional adenomas or by high-grade dysplasia strongly suggests that non-invasive conventional neoplasias might often precede GALT carcinomas in UC.

Expression of microRNA-155 in inflammatory bowel disease and its clinical significance

Objective: To explore the expression of microRNA-155 in colonic mucosa and peripheral blood in patients with inflammatory bowel disease(IBD), and to examine the clinical value and significance of microRNA-155 in the diagnosis of IBD. Methods: Quatitative reverse-transcription PCR was performed to detect the expression of microRNA-155 in 20 patients with Crohn disease(CD), 21 patients with ulcerative colitis (UC), 18 patients with IBD type unclassified(IBDU), 25 healthy people(control group), 12 patients with infection colitis and 19 patients with ischemia colitis.Receiver operating characteristic (ROC) curve was performed to analyze the clincal value of microRNA-155 in diagnosis of IBD. Results: The expression of microRNA-155 in colonic mucosa in CD, UC and IBDU group was significantly higher than that in control group(P<0.05). MicroRNA-155 expression was also significantly higher in UC group in comparison to CD group (35.4±3.0 vs 18.6±5.9, P<0.01), IBDU group in comparison to CD group (23.0±3.7 vs 18.6±5.9, P<0.05) and UC group in comparison to IBDU group (35.4±3.0 vs 23.0±3.7, P<0.01). The plasma level of microRNA-155 in UC group (55.6±2.5) and IBDU group (48.1±6.2) was significantly higher than that in control group(P<0.05), while no significant difference in CD group was observed when compared with control group(P>0.05). ROC curve shows an AUC of 0.83 and 95%CI of 0.679-0.986 of microRNA-155 expression in colonic mucosa.The sensitivity and specificity of microRNA-155 expression in colonic mucosa in diagnosis of IBD was 68.4% and 78.6%, respectively. Conclusions: MicroRNA-155 showed high expression in colonic mucosa and peripheral blood in patients with IBD.MicroRNA-155 shows promise as a biomarker in diagnosis of IBD.Furthermore, the aberrant expression indicates that microRNA-155 may be involved in pathogenesis and progression of IBD.

Dysplasia can be a pain in the gut

In the gastrointestinal tract, the term 'dysplasia' is used to refer to non-invasive neoplastic epithelium. Although we recognise adenomas of the gut as dysplastic, we don't use the term 'dysplasia' in reporting them. The use of the term 'dysplasia' for pre-invasive epithelium gradually came to replace other terms in studies attempting to identify epithelial changes that were cancer precursors in surveillance biopsies of patients with chronic colitides. The two-tier system of classification, dividing dysplasias into low-grade or high-grade lesions is conceptually straightforward; however, difficulties exist in the distinction of regenerative epithelium from low-grade dysplasia, of low-grade from high-grade dysplasia, and in identifying superficially invasive carcinoma in a dysplastic mucosa. The category 'indefinite for dysplasia' is an honest recognition of the difficulties in distinguishing reactive or regenerative epithelium from low-grade dysplasia, since these epithelia share many cytological features. In surveillance biopsies in ulcerative colitis and Barrett's mucosa, for each epithelial category from non-dysplastic through indefinite, low-grade and high-grade dysplasia, there are specific management recommendations that vary from no change in surveillance to increased surveillance to definitive therapy that is often a major resection. The recommendation for referral of high-grade dysplasias to consultants reflects the concern pathologists have about making such clinically significant diagnoses with limited experience. Pathologists should use the accepted terminology, share cases to expand their experience, and seek consultation in selected cases. This paper follows the evolution of the dysplasia concept, details the difficult areas of diagnosis, and discusses the importance of interaction between clinicians and pathologists in dealing with dysplasias.

Peroxiredoxin 1 expression in active ulcerative colitis mucosa identified by proteome analysis and involvement of thioredoxin based on immunohistochemistry.

Ulcerative colitis (UC) is a chronic, relapsing, inflammatory bowel disease, and patients with long-standing UC are at high risk of developing colorectal cancer as a typical case of the organ-specific chronic inflammation-carcinoma sequence. Interactions between epithelial and stromal cells and alterations in a variety of stromal microenvironments have been demonstrated to have important roles in the carcinogenesis of UC-associated carcinoma. Therefore, the identification of proteins in the inflammatory microenvironment is important not only in the epithelium, however also in the stroma of UC inflammatory foci. To identify proteins associated with UC-associated carcinoma, the present study used proteomic analysis with two-dimensional electrophoresis and mass spectrometry. Differentially expressed proteins were assessed between active and inactive UC biopsy specimens. Results were verified by immunohistochemistry. Peroxiredoxin 1 (PRDX1) was among the proteins identified to have increased expression in active compared with inactive UC. Immunohistochemical analysis indicated that the expression of both PRDX1 and thioredoxin (TRX) increased with increasing inflammation grade in epithelial cells in UC mucosal crypts. PRDX1-positive stromal cells in the lower half of the lamina propria increased along with colitis severity. Furthermore, the expression of both PRDX1 and TRX proteins was increased in UC-associated neoplastic lesions compared with normal mucosa. A stepwise increase in PRDX1 expression was clear with increasing tumor progression in UC-associated tumorigenesis. Since PRDX1 and TRX overexpression was a unique characteristic of UC activity and UC-associated neoplastic lesions, PRDX1 and TRX expression may reflect oxidative stress along with the severity of colitis activity and UC-associated tumorigenesis in patients with UC.

Expression and Clinical Significance of Elafin in Inflammatory Bowel Disease.

The expression of elafin in inflammatory bowel disease (IBD) is controversial. Here, we detected the expression of elafin in the peripheral blood and colonic mucosa of patient with IBD and then explored its role and value in assessing the activity and severity of IBD. Sixty-eight patients with IBD were selected as an experimental group. The control group included 38 healthy individuals. The expression of elafin mRNA in peripheral blood leukocytes and in serum was detected by qRT-PCR and enzyme-linked immunosorbent assay, respectively. The inflamed and noninflamed tissues were collected by colonoscopy. The expression of elafin in the intestinal mucosa was determined by immunohistochemistry staining and qRT-PCR. The expression of elafin between groups and among each stage of IBD was compared. The correlations of elafin expression with erythrocyte sedimentation rate and C-reactive protein were determined by Spearman's correlation analysis and with clinical disease activity indices (Best Crohn's Disease Activity Index and modified Mayo scores) by Pearson's correlation analysis. Elafin mRNA levels decreased significantly in active ulcerative colitis (UC) but increased in remission UC. However, in Crohn's disease (CD), we did not detect the aforementioned significant differences. Although serum IL-8 levels increased, serum elafin concentrations decreased both in UC and in CD, but the differences among stages were not significant. The expression of elafin in the inflamed colonic mucosa in both CD and UC was lower than that in the normal mucosa in controls and lower than that in the noninflamed mucosa in IBD. Moreover, the relative expression of elafin mRNA in peripheral blood leukocytes in UC was negatively correlated with erythrocyte sedimentation rate, C-reactive protein, and modified Mayo scores, and in CD, it was negatively correlated with Best Crohn's Disease Activity Index scores. Elafin decreased in active patients with IBD and was negatively correlated with disease activity, suggesting that elafin may play a protective role and could be used as an index to evaluate disease activity in IBD.