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:Nutrition consistently affects microbe-host interactions in the gastrointestinal tract. This study aimed to unravel how undernutrition reshapes the microbial composition and the homeostasis of epithelium in the jejunum and ileum. Sixteen late-gestation Hu-sheep were randomly assigned to the control group (n = 8, 100% ad libitum feeding levels) or the undernutrition group (n = 8, which received 30% ad libitum feeding levels). After 15-d treatment, all ewes were slaughtered, and jejunal and ileal digesta and epithelium samples were collected for 16S rRNA gene sequencing and transcriptome sequencing, respectively. Results indicated that undernutrition decreased the jejunal and ileal tissue weights (P = 0.005 and P = 0.022) and the levels of volatile fatty acids (P = 0.019 and P = 0.007) and microbial protein levels (P = 0.019 and P = 0.031) in jejunal and ileal digesta. The relative abundance of acetate producing microbiota, including Clostridia UCG-014 norank, Ruminococcus, [Ruminococcus] gauvreauii, and Lachnospiraceae _Blautia, were significantly reduced (P < 0.05) in the jejunum and ileum. Undernutrition up-regulated (P < 0.05) the expression of genes involved in amino acid synthesis and fatty acid oxidation, but down-regulated (P < 0.05) the expression of genes associated with amino acid degradation, fatty acid synthesis, and extracellular structures in jejunal and ileal epithelium. In the jejunal epithelium, genes associated with extracellular matrix-receptor interactions, cell growth, and immune response were down-regulated (P < 0.05) upon undernutrition. Taken together, undernutrition changed the microbial community in the jejunum and ileum, which altered the fermentation mode and the production of volatile fatty acids and microbial protein. These affected the energy and protein system in the epithelium and reprogrammed substance metabolism and extracellular structures, which probably further influenced cell growth and immune response. These insights provide a foundation for completely clarifying the crosstalk between small intestinal microbiota and the host.
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:Eating habits are closely related to the body's nutrient absorption and metabolic homeostasis. In order to better reveal the changes of intestinal epithelial cells under different dietary patterns, we examined the changes of gene expression profiles in jejunal epithelial cells of mice after 10 days of breakfast skipping feeding pattern by RNA sequencing.
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.