Project description:Transcriptional profiling of mouse jejunal epithelia comparing Tcrbd-/-, DAOwt/wt mouse and Tcrbd-/-, DAOG181R/G181R Intestinal microbiota produce D-amino acids, which are bacteria-specific metabolites, for regulation of bacterial cell wall integrity. Host intestine releases D-amino acid oxidase (DAO) to degrade bacterial D-amino acids, which shapes gut microbial community. However, it is not clarified whether bacterial D-amino acids affect host s immunity. In the present study, we compared mRNA expression in ileal epithelial tissue of DAO null mice with that of control mice in the absence of both T cell receptor beta and delta (Tcrb/d). Transcriptome analysis revealed up-regulation of inflammatory cytokines such as TNFa, IL1b, and IFNg in the epithelial tissue. Up-regulation of such cytokines could promote survival of na ve B cells and increase IgA-producing plasma cells, which in turn results in enhancement of IgA production. These results indicate that DAO controls intestinal immune responses through regulation of na ve B cells and differentiation of mature B cells.
Project description:In the current study, five late gestation multiparous ewes were restricted to a 30% feeding level to create a model of malnutrition, while five other ewes were fed normally as controls. All ewes were sacrificed and jejunal and ileal samples were collected for transcriptome sequencing to study metabolic changes.
Project description:The purpose of this study was to investigate the relative mRNA expression related to hormone, antioxidant capacity and immune responses in jejunal and ileal mucosa of healthy and postnatal growth retardation pigs. At 42 d of age, after overnight fasting, six postnatal growth retardation pigs and six healthy pigs were pair-matched by litter were selected for sampling. Samples of the jejunal and ileal mucosa were scraped and immediately snap-frozen in liquid nitrogen and stored at −80°C for RNA extraction. We used Roche LightCycler ® 480 Instrument PCR assay panel to quantitate gene expression of hormone, antioxidant capacity and immune responses relevant genes from jejunal and ileal mucosa.
Project description:Based on genetic risk factors and natural history, Crohn’s disease (CD) can be separated in two entities, an ileal and a colonic disease. Protein based-approaches are needed to elucidate whether such subphenotypes are related to distinct pathophysiological processes. In this work, we compared the proteome of ulcer edge to the one of paired control tissue in ileum and colon of CD patients. We revealed that ileal and colonic ulcer edge can be distinguished by a differential distribution of epithelial–mesenchymal transition proteins, neutrophil degranulation proteins and ribosomal proteins. In ileal and colonic ulcer edge, we found a quasi-systematic increase of the proteins implicated in the pathway of protein processing in endoplasmic reticulum and a quasi-systematic decrease of mitochondrial proteins. Our study provides for the first time protein-based evidences showing partly distinct pathophysiological processes associated to ileal and colonic ulcer edge in CD. This could constitute a first step toward the development of gut segment-specific diagnostic markers and therapeutics.
Project description:Crohn’s disease arises through host-environment interaction, with abnormal gene expression resulting from disturbed pathway activation or response to bacteria. Single cell RNA-sequencing of ileal tissue from 2 paediatric Crohn’s disease patients was performed, identifying populations of CD8+ effector memory T cells (CD8+ Tem), memory B-cells, monocytes, epithelial cells and plasma cells within the ileal tissue. Specialised epithelial cells driving differential expression of S100A8 and S100A9 and associated with defence to bacterium were identified, as well as IL17-signalling associated pathways in monocyte and epithelial cell populations.
Project description:GATA4 is expressed in the proximal 85% of small intestine where it promotes a proximal intestinal ('jejunal') identity while repressing a distal intestinal ('ileal') identity, but its molecular mechanisms are unclear. Here, we tested the hypothesis that GATA4 promotes a jejunal versus ileal identity in mouse intestine by directly activating and repressing specific subsets of absorptive enterocyte genes by modulating the acetylation of histone H3, lysine 27 (H3K27), a mark of active chromatin, at sites of GATA4 occupancy. Global analysis of mouse jejunal epithelium showed a statistically significant association of GATA4 occupancy with GATA4-regulated genes. Occupancy was equally distributed between down- and up-regulated targets, and occupancy sites showed a dichotomy of unique motif over-representation at down- versus up-regulated genes. H3K27ac enrichment at GATA4-binding loci that mapped to down-regulated genes (activation targets) was elevated, changed little upon conditional Gata4 deletion, and was similar to control ileum, whereas H3K27ac enrichment at GATA4-binding loci that mapped to up-regulated genes (repression targets) was depleted, increased upon conditional Gata4 deletion, and approached H3K27ac enrichment in wild-type control ileum. These data support the hypothesis that GATA4 both activates and represses intestinal genes, and show that GATA4 represses an ileal program of gene expression in the proximal small intestine by inhibiting the acetylation of H3K27. 2 samples were analyzed (1 ChIPseq, 1 input sample), control was done by confirming ChIP-qPCR on specific targets
Project description:<p>Although nonstarch polysaccharides often have growth-promoting effects in animals, little is known about how polysaccharides act when administered as feed additives. Here, we demonstrate that Amomum longiligulare polysaccharide 1 (ALP1) improves the growth performance of piglets by promoting the proliferation of jejunal epithelial cells. ALP1 can be absorbed by jejunal epithelial cells via endocytosis and increases the ratio of cells in the S and G2/M phases by increasing the expression of CDK4 and Cyclin E, which increases the number of proliferating cells. The gut microbiota is an important regulatory target of polysaccharides. ALP1 supplementation can increase the abundance of Lactobacillus in the jejuna of piglets, resulting in a high abundance of 11Z-eicosenoic acid (EA). In addition, EA increases the villus length in the jejunum by promoting cell proliferation. Our findings indicate that oral ALP1 supplementation promotes growth by direct (acting on jejunal epithelial cells) and indirect (acting on jejunal microbiota) mechanisms.</p>