Genome wide impact of loss of mechanoluminal stimulation on neonatal intestine
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ABSTRACT: Purpose: Surgical treatment of congenital and neonatal intestinal diseases often requires resection of intestine and/or diverstion of luminal flow. Subsequent growth on enteral nutrition alone depends on adaptation of the remaining bowel. The role of mechanoluminal stimulation in driving intestinal adaptation and the effects of depriving the intestine of mechanoluminal stimulation are unknown. Methods: 5 pairs of intestine from neonatal surgical patients were obtained at ileostomy reversal. The proximal segment contiguous with enteral feeding was denoted “fed” and the distal segment without luminal flow was denoted “unfed". Following RNA extraction, these samples underwent deep sequencing. Results: Fed intestine had increased expression of genes involved in inflammation and immune regulation and steroid secretion. Unfed intestine had increased expression of genes involved in digestion and transport. Conclusion: Independent of external influences, the presence or absence of enteral mechanoluminal stimulation causes significant alterations in gene expression in intestine.
Project description:Recent studies indicated that obestatin may play a regulatory role in the development of gastrointestinal track in the early postnatal period. The project aimed to understand the effect of obestatin in the development of structure and function ot he small intestine in the early postnatal period. Results shown that enteral administration of obestatin to suckling rats significanlty effects on activity of brush border enzymes, morphometry of intestinal wall as well as small intestinal epithelial renewal. The effect of observed changes was dependent on the segment of intestine studied. Significant changes in the transcriptomic gene profile were founded both in the middle part of intestine and stomach
Project description:Purpose: The intestine's main function is to digest and absorb dietary nutrients, with help from the absorptive epithelium and underlying vasculature and lymphatic system, as well as the microbiome. The intestine also houses the largest immune cell population in the body, tasked with providing resistance to toxins and invading pathogens while maintaining tolerance to dietary and microbial antigens, either by local action or lymphatic trafficking to the gut-draining lymph nodes (gLNs) to mount adaptive responses. While previous studies revealed the drainage map to various gLNs along the murine gut, and described immunological differences between gLNs, the underlying cellular components and the functional consequences of gut segment-specific drainage have not been systematically addressed. We sought to understand how compartmentalized lymphatic drainage of the intestinal milieu contributes to immune responses towards luminal antigens. Results: Here we report that gLNs are immunologically unique according to the functional gut segment they drain. Stromal and dendritic cell gene signatures, as well as adaptive T cell polarization against the same luminal antigen, differed between gLNs along the intestine, the proximal small intestine–draining gLNs preferentially giving rise to tolerogenic and the distal gLNs to pro-inflammatory T cell responses. This compartmentalized dichotomy could be perturbed by duodenal infection, surgical removal of select distal gLNs, dysbiosis, or ectopic antigen delivery, impacting both lymphoid organ and tissue immune responses. Conclusions: Our findings reveal that the conflict between tolerogenic and inflammatory adaptive responses is in part resolved by discrete gLN drainage, and encourage gut segment-specific antigen targeting for therapeutic immune modulation.
Project description:Nutrition has a vital role in shaping the intestinal microbiome. The impact of nutrients and the consequences of enteral deprivation on the small intestinal mucosal microbiota, specifically in early life, has not been well described. Our aim was to study the impact of enteral deprivation on the small intestine mucosal microbiome and to search for factors that shape this interaction in early life. Host seem to be the most dominant factor in the structure of the early life mucosal microbial small intestine community. Under conditions of nutrient deprivation, there are specific changes in host proteomics. Further research is needed to better define and understand this host-microbe-nutrition interaction in the small intestine.
Project description:In many mammalian species, the intestinal epithelium is immature at birth. During the suckling to weaning transition, the intestine matures. This developmental transition is the result of a genetic program that is intrinsic to the gut and independent of luminal content, but its regulators have not been identified. We investigated the function of the transcriptional repressor Blimp-1 using mice with intestine-specific ablation of Blimp-1. Deletion of Blimp-1 results in growth retardation and excess neonatal mortality. Mutant mice lack all typical epithelial features of the suckling period and are born with features of adult-like intestine.
Project description:Monocytes are circulating short-lived macrophage precursors that are recruited on demand from the blood to sites of inflammation and challenge. In steady state, classical monocytes give rise to vasculature-resident cells that patrol the luminal side of the endothelium. In addition, classical monocytes feed macrophage compartments of selected organs, including barrier tissues, such as the skin and intestine, as well as the heart. Monocyte differentiation under conditions of inflammation has been studied in considerable detail. In contrast, monocyte differentiation under non-inflammatory conditions remains less well understood. Here we took advantage of a combination of cell ablation and precursor engraftment to investigate the generation of gut macrophages from monocytes. Collectively, we identify factors associated with the gradual adaptation of monocytes to tissue residency. Moreover, comparison of monocyte differentiation into the colon and ileum-resident macrophages revealed the graduated acquisition of gut segment-specific gene expression signatures.
Project description:In many mammalian species, the intestinal epithelium is immature at birth. During the suckling to weaning transition, the intestine matures. This developmental transition is the result of a genetic program that is intrinsic to the gut and independent of luminal content, but its regulators have not been identified. We investigated the function of the transcriptional repressor Blimp-1 using mice with intestine-specific ablation of Blimp-1. Deletion of Blimp-1 results in growth retardation and excess neonatal mortality. Mutant mice lack all typical epithelial features of the suckling period and are born with features of adult-like intestine. To assess the function of the gene Prdm1 (Blimp) on postnatal day 7 intestinal epithelium, VillinCre-Blimpflox and control (VillinCre-Blimpwt or Cre-Blimpflox) mice were generated. Mice were sacrificed at day 7 postnatal, and pieces of whole mid-intestine were taken for analysis.
Project description:The small intestinal epithelium is composed of several defined epithelial cell lineages, which in turn exhibit marked transcriptional and functional diversity along the crypt-villus and proximal-to-distal length of the intestinal tract. While epithelial cell type and functional heterogeneity have been characterized in the adult intestinal epithelium, the temporal and spatial changes during the postanatal period, which accompany the transition from placental energy supply to enteral feeding and facilitate the establishment of the enteric microbiota and postnatal immune maturation, have not been systematically investigated. Here, we analyzed the small intestinal epithelium of 1-, 5-, 10- and 25-day-old SPF mice by single cell RNA-Seq and used differential gene expression and pathway analysis to identify age-specific expression patterns. In addition, the influence of enteric infection on the neonatal epithelium was investigated. We identify gene clusters temporally expressed in the neonatal intestine and correlate their expression with the functional changes during postnatal tissue maturation and the neonate to adult transition.
Project description:The small intestine is the primary organ for nutrient sensing and absorption, in order to more comprehensively reveal the nutrient sensing and response of intestinal cells, we used ATAC sequencing to reveal the effects of enteral and serosal nutrients on the intestinal tract in a bidirectional nutrient supply mode.
Project description:Caesarean-delivered preterm pigs were fed 3 d of parenteral nutrition followed by 2 d of enteral formula feeding. Antibiotics (n=11) or control saline (n=13) were given twice daily from birth to tissue collection at d 5. NEC-lesions and intestinal structure, function, microbiology and immunity markers were recorded. We used Affymetrix microarrays to investigate gene expression in intestinal tissues of preterm piglets treated with antibiotics or control saline. Twenty-four preterm piglets were delivered by caesarean section on day 105 of gestation from two healthy sows. All piglets were initially provided with parenteral nutrition via a vascular catheter, combined with small amounts of minimal enteral nutrition. On day three, all parenteral nutrition was stopped and total enteral nutrition was given through an oro-gastric feeding tube. Piglets were allocated into controls ( n=13) and an intervention group receiving oral and systemic broad-spectrum antibiotics ( n=11). To assure high systemic and intra luminal MIC values antibiotics were given both orally and intramuscularly. All antibiotics were given directly after feeding with an oral bolus and control pigs were given corresponding amounts of saline. On day five, all piglets were euthanized, and small intestinal tissue collected.