Project description:Management of terminal ileal Crohn's disease (CD) is difficult due to fibrotic prognosis and failure to achieve mucosal healing. A limited number of synchronous analyses have been conducted on the transcriptome and microbiome in unpaired terminal ileum tissues. Therefore, our study focused on the transcriptome and mucosal microbiome in terminal ileal tissues of CD patients with the aim of determining the role of cross-talk between the microbiome and transcriptome in the pathogenesis of terminal ileal CD. Mucosa-attached microbial communities were significantly associated with segmental inflammation status. Interaction-related transcription factors (TFs) are the panel nodes for crosstalk between the gene patterns and microbiome for terminal ileal CD. The transcriptome and microbiome in terminal ileal CD can be different related to local inflammatory status, and specific differentially expressed genes (DEGs) may be targeted for mucosal healing. TFs connect gene patterns with the microbiome by reflecting environmental stimuli and signals from microbiota.
Project description:The widely varying therapeutic response of patients with inflammatory bowel disease (IBD) continues to raise questions regarding the unclarified heterogeneity of pathological mechanisms promoting disease progression. While biomarkers for the differentiation of Crohn's disease (CD) versus ulcerative colitis (UC) have been suggested, specific markers for a CD subclassification in ileal CD versus colonic CD are still rare. Since an altered signature of the tryptophan metabolism is associated with chronic inflammatory disease, we sought to characterize potential biomarkers by focusing on the downstream enzymes and metabolites of kynurenine metabolism. Using immunohistochemical stainings, we analyzed and compared the mucosal tryptophan immune metabolism in bioptic samples from patients with active inflammation due to UC or CD versus healthy controls. Localization-specific quantification of immune cell infiltration, tryptophan-metabolizing enzyme expression and mucosal tryptophan downstream metabolite levels was performed. We found generally increased immune cell infiltrates in the tissue of all patients with IBD. However, in patients with CD, significant differences were found between regulatory T cell and neutrophil granulocyte infiltration in the ileum compared with the colon. Furthermore, we observed decreased kynurenine levels as well as strong kynureninase (KYNU) expression specifically in patients with ileal CD. Correspondingly, significantly elevated levels of the kynurenine metabolite 3-hydroxyanthranilic acid were detected in the ileal CD samples. Highlighting the heterogeneity of the different phenotypes of CD, we identified KYNU as a potential mucosal biomarker allowing the localization-specific differentiation of ileal CD versus colonic CD.
Project description:Previous genome-wide expression studies have highlighted distinct gene expression patterns in inflammatory bowel disease (IBD) compared to control samples, but the interpretation of these studies has been limited by sample heterogeneity with respect to disease phenotype, disease activity, and anatomic sites. To further improve molecular classification of inflammatory bowel disease phenotypes we focused on a single anatomic site, the disease unaffected proximal ileal margin of resected ileum, and three phenotypes that were unlikely to overlap: ileal Crohn's disease (ileal CD), ulcerative colitis (UC), and control patients without IBD. Whole human genome (Agilent) expression profiling was conducted on two independent sets of disease-unaffected ileal samples collected from the proximal margin of resected ileum. Set 1 (47 ileal CD, 27 UC, and 25 Control non-IBD patients) was used as the training set and Set 2 was subsequently collected as an independent test set (10 ileal CD, 10 UC, and 10 control non-IBD patients). We compared the 17 gene signatures selected by four different feature-selection methods to distinguish ileal CD phenotype with non-CD phenotype. The four methods yielded different but overlapping solutions that were highly discriminating. All four of these methods selected FOLH1 as a common feature. This gene is an established biomarker for prostate cancer, but has not previously been associated with Crohn's disease. Immunohistochemical staining confirmed increased expression of FOLH1 in the ileal epithelium. These results provide evidence for convergent molecular abnormalities in the macroscopically disease unaffected proximal margin of resected ileum from ileal CD subjects.
Project description:Management of terminal ileal Crohn disease (CD) is difficult due to fibrotic prognosis and failure to achieve mucosal healing. A limited number of synchronous analyses have been conducted on the transcriptome and microbiome in unpaired terminal ileum tissues. Therefore, our study focused on the transcriptome and mucosal microbiome in terminal ileal tissues of patients with CD with the aim of determining the role of cross-talk between the microbiome and transcriptome in the pathogenesis of terminal ileal CD. Mucosa-attached microbial communities were significantly associated with segmental inflammation status. Interaction-related transcription factors (TFs) are the panel nodes for cross-talk between the gene patterns and microbiome for terminal ileal CD. The transcriptome and microbiome in terminal ileal CD can be differently related to the local inflammatory status, and specific differentially expressed genes may be targeted for mucosal healing. TFs connect gene patterns with the microbiome by reflecting environmental stimuli and signals from microbiota.
Project description:We have previously identified NOD2 genotype and inflammatory bowel diseases (IBD) phenotype, as associated with shifts in the ileal microbiome ("dysbiosis") in a patient cohort. Here we report an integrative analysis of an expanded number of Crohn's disease (CD) related genetic defects in innate immune function (NOD2, ATG16L1, IRGM, CARD9, XBP1, ORMDL3) and composition of the ileal microbiome by combining the initial patient cohort (Batch 1, 2005-2010, n = 165) with a second consecutive patient cohort (Batch 2, 2010-2012, n = 118). These combined patient cohorts were composed of three non-overlapping phenotypes: 1.) 106 ileal CD subjects undergoing initial ileocolic resection for diseased ileum, 2.) 88 IBD colitis subjects without ileal disease (predominantly ulcerative colitis but also Crohn's colitis and indeterminate colitis, and 3.) 89 non-IBD subjects. Significant differences (FDR < 0.05) in microbiota were observed between macroscopically disease unaffected and affected regions of resected ileum in ileal CD patients. Accordingly, analysis of the effects of genetic and clinical factors were restricted to disease unaffected regions of the ileum. Beta-diversity differed across the three disease categories by PERMANOVA (p < 0.001), whereas no significant differences in alpha diversity were noted. Using negative binomial models, we confirmed significant effects of IBD phenotype, C. difficile infection, and NOD2 genotype on ileal dysbiosis in the expanded analysis. The relative abundance of the Proteobacteria phylum was positively associated with ileal CD and colitis phenotypes, but negatively associated with NOD2R genotype. Additional associations with ORMDL3 and XBP1 were detected at the phylum/subphylum level. IBD medications, such as immunomodulators and anti-TNFα agents, may have a beneficial effect on reversing dysbiosis associated with the IBD phenotype. Exploratory analysis comparing microbial composition of the disease unaffected region of the resected ileum between 27 ileal CD patients who subsequently developed endoscopic recurrence within 6-12 months versus 34 patients who did not, suggested that microbial biomarkers in the resected specimen helped stratify patients with respect to risk of post-surgical recurrence.
Project description:ObjectivesMagnetic resonance enterography (MRE) interpretation of Crohn's disease (CD) is subjective and uses 2D analysis. We evaluated the feasibility of volumetric measurement of terminal ileal CD on MRE compared to endoscopy and sMARIA, and the responsiveness of volumetric changes to biologics.MethodsCD patients with MRE and contemporaneous CD endoscopic index of severity-scored ileocolonoscopy were included. A centreline was placed through the terminal ileum (TI) lumen defining the diseased bowel length on the T2-weighted non-fat saturated sequence, used by two radiologists to independently segment the bowel wall to measure volume (phase 1). In phase 2, we measured disease volume in patients treated with biologics, who had undergone pre- and post-treatment MRE, with treatment response classified via global physician assessment.ResultsPhase 1 comprised 30 patients (median age 29 (IQR 24, 34) years). Phase 2 included 12 patients (25 years (22, 38)). In phase 1, the mean of the radiologist-measured volumes was used for analysis. The median disease volume in those with endoscopically active CD was 20.9 cm3 (IQR 11.3, 44.0) compared to 5.7 cm3 (2.9, 9.8) with normal endoscopy. The mean difference in disease volume between the radiologists was 3.0 cm3 (limits of agreement -21.8, 15.9). The median disease volume of patients with active CD by sMARIA was 15.0 cm3 (8.7, 44.0) compared to 2.85 cm3 (2.6, 3.1) for those with inactive CD. Pre- and post-treatment median disease volumes were 28.5 cm3 (26.4, 31.2), 11 cm3 (4.8, 16.6), respectively in biological responders, vs 26.8 cm3 (12.3, 48.7), 40.1 cm3 (10, 56.7) in non-responders.ConclusionVolumetric measurement of terminal ileal CD by MRE is feasible, related to endoscopy and sMARIA activity, and responsive to biologics.Clinical relevance statementMeasuring the whole volume of diseased bowel on MRE in CD is feasible, related to how biologically active the disease is when assessed by endoscopy and by existing MRE activity scores, and is sensitive to treatment response.Key pointsMRE reporting for CD is subjective and uses 2D images rather than assessing the full disease volume. Volumetric measurement of CD relates to endoscopic activity and shows reduced disease volumes in treatment responders. This technique is an objective biomarker that can assess disease activity and treatment response, warranting validation.
Project description:Crohn's disease is a lifelong disease characterized by chronic inflammation of the gastrointestinal tract. Defining the cellular and transcriptional composition of the mucosa at different stages of disease progression is needed for personalized therapy in Crohn's. Ileal biopsies were obtained from (1) control subjects (n = 6), (2) treatment-naïve patients (n = 7), and (3) established (n = 14) Crohn's patients along with remission (n = 3) and refractory (n = 11) treatment groups. The biopsies processed using 10x Genomics single cell 5' yielded 139 906 cells. Gene expression count matrices of all samples were analyzed by reciprocal principal component integration, followed by clustering analysis. Manual annotations of the clusters were performed using canonical gene markers. Cell type proportions, differential expression analysis, and gene ontology enrichment were carried out for each cell type. We identified 3 cellular compartments with 9 epithelial, 1 stromal, and 5 immune cell subtypes. We observed differences in the cellular composition between control, treatment-naïve, and established groups, with the significant changes in the epithelial subtypes of the treatment-naïve patients, including microfold, tuft, goblet, enterocyte,s and BEST4+ cells. Surprisingly, fewer changes in the composition of the immune compartment were observed; however, gene expression in the epithelial and immune compartment was different between Crohn's phenotypes, indicating changes in cellular activity. Our study identified cellular and transcriptional signatures associated with treatment-naïve Crohn's disease that collectively point to dysfunction of the intestinal barrier with an increase in inflammatory cellular activity. Our analysis also highlights the heterogeneity among patients within the same disease phenotype, shining a new light on personalized treatment responses and strategies.
Project description:Gut bacteriome dysbiosis is known to be implicated in the pathogenesis of inflammatory bowel disease (IBD). Crohn's disease (CD) is an IBD subtype with extensive mucosal inflammation, yet the mucosal virome, an empirical modulator of the bacteriome and mucosal immunity, remains largely unclear regarding its composition and role. Here, we exploited trans-cohort CD patients and healthy individuals to compositionally and functionally investigate the small bowel (terminal ileum) virome and bacteriome. The CD ileal virome was characterised by an under-representation of both lytic and temperate bacteriophages (especially those targeting bacterial pathogens), particularly in patients with flare-up. Meanwhile, the virome-bacteriome ecology in CD ileal mucosa was featured by a lack of Bifidobacterium- and Lachnospiraceae-led mutualistic interactions between bacteria and bacteriophages; surprisingly it was more pronounced in CD remission than flare-up, underlining the refractory and recurrent nature of mucosal inflammation in CD. Lastly, we substantiated that ileal virions from CD patients causally exacerbated intestinal inflammation in IBD mouse models, by reshaping a gut virome-bacteriome ecology preceding intestinal inflammation (microbial trigger) and augmenting microbial sensing/defence pathways in the intestine cells (host response). Altogether, our results highlight the significance of mucosal virome in CD pathogenesis and importance of mucosal virome restoration in CD therapeutics.
Project description:We report the global pattern of ileal gene expression in a cohort of 310 treatment-naïve pediatric Crohn Disease patients and controls. We focus on genes with consistent altered expression in the ileum of younger (Paris age A1a) vs older (Paris age A1b) patients.