Core Ileal Transcriptome in Pediatric Crohn Disease
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ABSTRACT: We report the global pattern of ileal gene expression in a cohort of 359 treatment-naïve pediatric Crohn Disease, Ulcerative Colitis patients and controls. We focus on genes with consistent altered expression in inflamed and unaffected ileum of CD [ileal-involved CD (iCD) and non-invloved ileal CD (cCD)], but not in the ileum of ulcerative colitis or control.
Project description:The aim of this study is to identify early pathogenic changes in ileal gene expression that precede the development of macroscopic disease in inflammatory bowel diseases (IBDs). We focused on two IBD phenotypes that were unlikely to overlap: 1) ileal Crohn’s disease (CD) patients undergoing initial ileocolic resection of diseased ileum; and 2) ulcerative colitis (UC) patients undergoing total colectomy. The Control patients were those patients without IBD undergoing initial right hemicolectomy or total colectomy. In order to identify early pathogenic changes in the human ileum in inflammatory bowel diseases, we analyzed 99 two-color whole human genome expression profiles (Agilent 4410A) of a test human ileal cRNA probe vs. a common reference human ileal RNA from a Control patient (N17). A minimum of four biopsies were taken from the macroscopically disease-unaffected proximal ileal margin of freshly resected specimens from 47 ileal Crohn's disease patients undergoing initial ileocolic resection, 27 ulcerative colitis patients undergoing total colectomy and 25 Control patients undergoing either right hemicolectomy or total colectomy. The test and common reference probes were synthesized using the Agilent Low Input Linear Amplification Kit. Hybridization was carried out in DNA hybridization chambers, washed and scanned on an Axon GenePix 4000B scanner. The preprocessing, filtering and normalization of the array data was carried out using the R package LIMMA.
Project description:We previously showed that abnormal morphology phenotype of ileal Paneth cells (Paneth cell phenotype [PCP]; as a surrogate for PC function) correlate with genetics, microbiota compositions, and aggressive outcome in Crohn’s disease (CD) patients. Given the shared genetics and clinical features between CD and ulcerative colitis (UC), we hypothesized that abnormal PCP also negatively modulates UC outcomes. As PCs has the highest density in the ileum, we further hypothesized that abnormal PCP from the terminal ileum could increase the risk of development of pouch complications after UC total colectomy and ileal pouch anal anastomosis (IPAA).
Project description:Samples for microarray analysis were derived from terminal ileum and colonic tissues from probands with Crohn´s disease and Ulcerative Colitis and control patients, respectively. IBD tissue biopsies from non-inflamed regions 10 cm distant from pathological areas were selected. To minimize inter-individual differences in gene expression and to enrich for IBD-specific transcriptional events, 2.5 µg of total RNA from terminal ileum and colon transversum from four individuals of each patient and control group were used for pooling. Keywords = IBD Keywords = Crohn´s disease Keywords = Ulcerative Colitis Keywords: other
Project description:The aim of this study is to identify early pathogenic changes in ileal gene expression that precede the development of macroscopic disease in inflammatory bowel diseases (IBDs). We focused on two IBD phenotypes that were unlikely to overlap: 1) ileal Crohn’s disease (CD) patients undergoing initial ileocolic resection of diseased ileum; and 2) ulcerative colitis (UC) patients undergoing total colectomy. The Control patients were those patients without IBD undergoing initial right hemicolectomy or total colectomy.
Project description:<p>This study involved evaluation of the tissue associated microbiome of the ileal pouch following surgery for ulcerative colitis (UC) or familial adenomatous polyposis (FAP). Individuals were recruited, with biopsies taken from the ileal pouch and the pre-pouch ileum, microbial DNA was extracted and sequenced using 454 pyrosequencing. Total bacterial community structure and abundance were evaluated to determine which changes were characteristic of inflammatory phenotypes including pouchitis (inflammation of the ileal pouch) and a Crohn's disease-like phenotype.</p>
Project description:Objective: Long non-coding RNAs (lncRNA) regulate gene transcription and diverse cellular functions. We previously defined a novel core inflammatory and metabolic ileal gene signature in treatment naïve pediatric Crohn Disease (CD), however, genome-wide characterization of lncRNA expression was lacking. We now extend our analyses to define a more comprehensive view that includes lncRNA. Design: Using RNAseq, we performed a systematic profiling of lncRNAs and protein-coding genes expression in 177 ileal biopsies. Co-expression analysis was used to identify functions and tissue-specific expression. RT-PCR was used to test lncRNAs regulation by IL-1β in Caco-2 enterocytes model. Results: We characterize a widespread dysregulation of 459 lncRNA in the ileum of treatment naïve pediatric CD patients. Unsupervised and supervised classifications using the 459 lncRNA showed comparable patients’ grouping as the 2160 dysregulated protein-coding genes, linking lncRNA to CD pathogenesis. Co-expression and functional annotation enrichment analyses across several tissues and cell types showed that the up-regulated LINC01272 is associated with a myeloid pro-inflammatory signature while the down-regulated HNF4A-AS1 exhibits association with an epithelial metabolic signature. We further validated expression and regulation of prioritized lncRNA upon IL-1β exposure in differentiated Caco-2 cells. Finally, we identified significant correlations between LINC01272 and HNF4A-AS1 expression and more severe mucosal injury. Conclusion: We define differentially expressed lncRNA in the ileum of treatment naive pediatric CD. We show lncRNA utility to correctly classify disease or healthy states and demonstrate their regulation in response to an inflammatory signal. These lncRNA, after mechanistic exploration, may serve as potential new targets for RNA-based interventions.
Project description:Long non-coding RNA (lncRNA) mechanisms in gut inflammation are poorly understood. Tissue-specificity of lncRNAs linked to patient outcomes may direct interventions with fewer off-target effects. Using 693 mucosal samples, we prioritize lncRNAs linked with ulcerative colitis (UC) course and define an atlas of lncRNAs expressed along the gastrointestinal tract dysregulated in celiac duodenum, Crohn Disease ileum, and UC rectum using independent test and validation cohorts.
Project description:Identification of significant regulated genes of the ileal epithelium in patients suffering from Crohn disease (normal vs. activ and non activ CD).
Project description:We report ileum gene expression of 37 controls and 158 patients with either Crohn's disease (n=112), ulcerative colitis (n=44), unclassifed IBD (1), or IBS (1). We contrast gene expression in African American (n=104) versus white (n=25) CD and UC patients.
Project description:Samples for microarray analysis were derived from terminal ileum and colonic tissues from probands with Crohn´s disease and Ulcerative Colitis and control patients, respectively. IBD tissue biopsies from non-inflamed regions 10 cm distant from pathological areas were selected. To minimize inter-individual differences in gene expression and to enrich for IBD-specific transcriptional events, 2.5 µg of total RNA from terminal ileum and colon transversum from four individuals of each patient and control group were used for pooling. Gene expression profiles were determined using Affymetrix HG-U133B Gene Chips. Keywords: ordered