Project description:Background: Restitution of the surface epithelium is a critical healing process early after ischaemic injury of the gut mucosa. Repeated episodes of intestinal ischaemia occur in many critically ill patients. This study evaluates the resistance of postischaemic restituted intestinal mucosa to a further ischaemic insult. Methods: The superior mesenteric artery (SMA) in pigs was cross-clamped for 1 hour, reperfused for 4 hours, cross-clamped once again for 1 hour, and finally reperfused for 3 hours. Intestinal injury was evaluated with morphometry. Intestinal permeability (from blood to lumen was assessed by transport of fluorescein isothiocyanate dextran (FD-4). Microarray and QRT-PCR analysis were performed.
Project description:The goal of the present study was to determine whether loss of the insulin receptor alters the molecular landscape of the intestinal mucosa, using intestinal-epithelial insulin receptor knockout (IE-irKO) mice and both genetic (IRfl/fl and Villin-cre) controls. Quantitative proteomic analysis by Liquid Chromatography Mass Spectrometry (LC-MS) was deployed on jejunal and colonic mucosa from mice fed a chow- or Western diet (WD). Jejunal mucosa from IE-irKO mice demonstrated alterations in all intestinal cell linages, Paneth, goblet, absorptive and enteroendocrine cells, whereas only goblet and absorptive cells were affected in the colon. There was also a significant effect of the WD on the gut proteome. A significant reduction was detected in Paneth cell proteins with anti-microbial activity, including lysozyme C-1, angiogenin-4, cryptdin-related sequence1C-3 and -2, a-defensin 17 and intelectin-1a. The key protein expressed by goblet cells, mucin-2, was also reduced in the IE-irKO mice. Proteins involved in lipid metabolism, including aldose reductase-related protein 1, 15-hydroxyprostaglandin dehydrogenase [NAD(+)], apolipoprotein A-II and pyruvate dehydrogenase kinase isozyme 4, were increased in the mucosa of WD-fed IE-irKO mice as compared to controls. In contrast, expression of the nutrient-responsive gut hormones, glucose-dependent insulinotropic polypeptide and neurotensin, was reduced in the jejunal mucosa of IE-irKO mice, and there was a reduction in proteins of the P-type ATPases and the solute carrier-transporter family in the colon of WD-fed IE-irKO mice. In conclusion, IE-irKO mice display a distinct molecular phenotype, suggesting a biological role of insulin and its receptor in determining differentiated cell-specificity in the intestinal epithelium.
Project description:Intestinal microbiota colonization is important for intestinal development and health of preterm infants, especially those with extremely low birth weight. Recent studies indicated for a dynamic crosstalk between that gut microbiota and DNA methylome of host intestinal cells. Thereby, we sought to determine the epigenomic and metagenomic consequences of suppression of microbiota colonization in the intestine of preterm neonates to gain insights into biological pathways that shape the interface between the gut microbiota and the preterm intestinal cells. We examined 14 preterm piglets by comparing the conventional preterm neonates with those ones treated with oral antibiotics for genome wide DNA methylation and 16S rDNA microbiome. Our results demonstrated an extensive genome-wide DNA methylation changes in response to the suppression of intestinal microbe colonization, especially genes involved in neonatal immune response signaling and glycol-metabolism pathways were identified. Our study highlights several key genes that might predispose preterm neonates to NEC risk due to their key roles involved in the immune-metabolic networks. Our study not only provided rich omic-data to interpret molecular program in relation with microbiota-associated methylome-proteome network changes, but also confer clinical usage of key gene markers for potential early diagnostics of NEC of preterm neonates.
Project description:To characterize the effect of microbiota on global gene expression in the distal small intestine during postnatal gut development we employed mouse models with experimental colonization by intestinal microbiota. Using microarray analysis to assess global gene expression in ileal mucosa at the critical stage of intestinal development /maturation associated with weaning, and asking how expression is affected by microbial colonization In the study presented here, preweaned and postweaned GF, SPF mouse small intestinal total RNAs were used. Also, 3-week-old gnotobiotic mouse as well as GF mouse small intestinal RNAs were used.
Project description:To characterize the effect of microbiota on global gene expression in the distal small intestine during postnatal gut development we employed mouse models with experimental colonization by intestinal microbiota. Using microarray analysis to assess global gene expression in ileal mucosa at the critical stage of intestinal development /maturation associated with weaning, and asking how expression is affected by microbial colonization