Project description:Paneth cells of intestinal crypts contribute to host defense by producing antimicrobial peptides that are packaged as granules for secretion into the crypt lumen. Here, we provide evidence using light and electron microscopy that postsecretory Paneth cell granules undergo limited dissolution and accumulate within the intestinal crypts of cystic fibrosis (CF) mice. On the basis of this finding, we evaluated bacterial colonization and expression of two major constituents of Paneth cells, i.e., {alpha}-defensins (cryptdins) and lysozyme, in CF murine intestine. Paneth cell granules accumulated in intestinal crypt lumens in both untreated CF mice with impending intestinal obstruction and in CF mice treated with an osmotic laxative that prevented overt clinical symptoms and mucus accretion. Ultrastructure studies indicated little change in granule morphology within mucus casts, whereas granules in laxative-treated mice appear to undergo limited dissolution. Protein extracts from CF intestine had increased levels of processed cryptdins compared with those from wild-type (WT) littermates. Nonetheless, colonization with aerobic bacteria species was not diminished in the CF intestine and oral challenge with a cryptdin-sensitive enteric pathogen, Salmonella typhimurium, resulted in greater colonization of CF compared with WT intestine. Modest downregulation of cryptdin and lysozyme mRNA in CF intestine was shown by microarray analysis, real-time quantitative PCR, and Northern blot analysis. Based on these findings, we conclude that antimicrobial peptide activity in CF mouse intestine is compromised by inadequate dissolution of Paneth cell granules within the crypt lumens. Keywords: other
Project description:Paneth cells of intestinal crypts contribute to host defense by producing antimicrobial peptides that are packaged as granules for secretion into the crypt lumen. Here, we provide evidence using light and electron microscopy that postsecretory Paneth cell granules undergo limited dissolution and accumulate within the intestinal crypts of cystic fibrosis (CF) mice. On the basis of this finding, we evaluated bacterial colonization and expression of two major constituents of Paneth cells, i.e., {alpha}-defensins (cryptdins) and lysozyme, in CF murine intestine. Paneth cell granules accumulated in intestinal crypt lumens in both untreated CF mice with impending intestinal obstruction and in CF mice treated with an osmotic laxative that prevented overt clinical symptoms and mucus accretion. Ultrastructure studies indicated little change in granule morphology within mucus casts, whereas granules in laxative-treated mice appear to undergo limited dissolution. Protein extracts from CF intestine had increased levels of processed cryptdins compared with those from wild-type (WT) littermates. Nonetheless, colonization with aerobic bacteria species was not diminished in the CF intestine and oral challenge with a cryptdin-sensitive enteric pathogen, Salmonella typhimurium, resulted in greater colonization of CF compared with WT intestine. Modest downregulation of cryptdin and lysozyme mRNA in CF intestine was shown by microarray analysis, real-time quantitative PCR, and Northern blot analysis. Based on these findings, we conclude that antimicrobial peptide activity in CF mouse intestine is compromised by inadequate dissolution of Paneth cell granules within the crypt lumens. Total RNA was extracted from pooled small intestines of three WT and three CF mice using Tri-Reagent (Molecular Research Center, Cincinnati, OH), and poly(A) RNA was purified by using the MicroPoly(A) mRNA purification kit (Ambion, Austin, TX). The WT and CF poly(A) RNA samples were sent to IncyteGenomics (St. Louis, MO) where they were labeled with cyanine 3 (Cy3) and Cy5, respectively, and hybridized with the UniGEM1.31 array representing 9,570 known genes and expressed sequence tags.
Project description:Here, we performed single cell RNA sequencing (scRNA-seq) of 1 (one) human fetal lung tissue specimen (18.9 week) and 2 (two) human fetal intestine specimens (12.1 and 18.9 week) (total of 3 (three) independent biological specimens). The data set is composed of approximately 5,000 lung cells and 7,500 intestine cells. Lineages captured across both tissues include but are not limited to epithelium, stroma, immune, neurons and endothelium.
Project description:Chorioamnionitis (CA), resulting from intra-amniotic inflammation, is a frequent cause of preterm birth and exposes the immature intestine to bacterial toxins and/or inflammatory mediators before birth via fetal swallowing. This may affect intestinal immune development, interacting with the effects of enteral feeding and gut microbiota colonization just after birth. Using preterm pigs as model for preterm infants, we hypothesized that prenatal exposure to gram-negative endotoxin influences postnatal bacterial colonization and gut immune development. Pig fetuses were given intra-amniotic lipopolysaccharide (LPS) 3 d before preterm delivery by cesarean section, and were compared with litter-mate controls (CON) at birth and after 5 d of formula feeding and spontaneous bacterial colonization. Amniotic fluid was collected for analysis of leukocyte counts and cytokines, and the distal small intestine was analyzed for endotoxin level, morphology and immune cell counts. Intestinal gene expression and microbiota were analyzed by transcriptomics and metagenomics, respectively. At birth, LPS-exposed pigs showed higher intestinal endotoxin, neutrophil/macrophage density and shorter villi. About 1.0% of intestinal genes were affected at birth and DMBT1, a regulator of mucosal immune defense, was identified as the hub gene in the co-expression network. Genes related to innate immune response (TLR2, LBP, CD14, C3, SFTPD), neutrophil chemotaxis (C5AR1, CSF3R, CCL5) and antigen processing (MHC II, CD4) were also affected and expression levels correlated with intestinal neutrophil/macrophage density and amniotic fluid cytokine levels. On day 5, LPS and CON pigs showed similar necrotizing enterocolitis (NEC) lesions, endotoxin levels, morphology, immune cell counts, gene expressions and microbiota (except for difference in some low-abundant species). Our results show that CA markedly affects intestinal genes at preterm birth, including genes related to immune cell infiltration. However, a few days later, following the physiological adaptations to preterm birth, CA had limited effects on intestinal structure, function, gene expression, bacterial colonization and NEC sensitivity. We conclude that short-term, prenatal intra-amniotic inflammation is unlikely to exert marked effects on intestinal immune development in preterm neonates beyond the immediate neonatal period.
Project description:Immortal spheroids were generated from fetal mouse intestine using the culture system developed to culture organoids from adult intestinal epithelium. Spheroids are made of a monostratified polarized epithelium displaying a poorly differentiated intestinal phenotype. The proportion of spheroids generated from intestinal explants progressively decreases from fetal to postnatal period, with a corresponding increase in production of organoids. Spheroid cells show indefinite self-renewing properties but exhibit a transcriptome strikingly different from that of adult intestinal stem cells reminiscent of incompletely caudalized progenitors. The receptor Lgr4, but not Lgr5, is essential for their growth. Trop2/Tacstd2 and Cnx43/Gja1, two markers highly enriched in spheroids, are expressed throughout the E14 intestinal epithelium. Comparison of in utero and neonatal lineage tracing using Cnx43-CreER and Lgr5-CreERT2 mice identified spheroid-generating cells as developmental progenitors involved in generation of the prenatal intestinal epithelium. Ex vivo, spheroid cells have the potential to differentiate into organoids, thus qualifying them as a new type of intestinal stem-like cells. Two-channel microarray experiments were performed from spheroid/organoid pairs isolated each from a given embryo. Following initial seeding of small intestine from a given embryo/mouse (at E16, E18 or P0), spheroids and organoids were selectively picked up for each animal and replated for 3 passages to reach sample homogeneity. Hybridization was performed on the 4 independent pairs with dye-swap.
Project description:Our focus of this study is to determine the gene expression changes in E. coli colonizing the mouse intestine as compared to E. coli grown in minimal medium in vitro. We colonized CD-1 male mice with E. coli MG1655 StrR wild type and extracted the total RNA from mouse cecal mucus. We also extracted E. coli MG1655 StrR RNA from in vitro culture and sequenced and compared to determine the genes important for E. coli colonization of the mammalian intestine. Our results indicate that OmpC is important for E. coli to colonize the mouse intestine as it is upregulated as compared to in vitro culture. OmpF is not important; it is detrimental for E. coli colonization of the mouse intestine and is highly downregulated in the colonized E. coli
Project description:We have compared the transcriptional profiles from three epithelial cell types to find common and differentially expressed genes. Epithelial cells from small intestine and kidney from C57BL/6 mice were sorted and their transcriptional profiles compared. Cells were gated as viable, Epcam+ CD45- for kidney, and viable, Epcam+ CD45- MHCIIhigh for small intestine MHCIIhi and viable, Epcam int CD45- MHCII low for small intestine MHCIIlo.
Project description:Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Here, we report the analysis of the transcriptome of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes represents metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of main virulence associated genes or known human colonization factors. Here, we document regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vwbp, located on SaPIbov5). Colonization with isogenic-deletion strains (Î?vwbp and Î?scpA) did not alter the nasal S. aureus colonization compared to wild type. Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Number of the samples: 5 (timepoint 0 min, 30 min, 60 min, 90 min and 180 min) in 4 replicates. 4 control samples
Project description:Gut microbiome modulates the host immune development, yet the functional contribution of gut fungi remains elusive. We previously showed that mice colonized only with fungi displayed allergic features and fecal metabolite profiles similar to germ-free mice. To gain insights into the functional changes attributed to fungal colonization, we performed proteomic analyses of feces and small intestine of gnotobiotic mice colonized with either bacteria, fungi, or both. Comparison of fecal metaproteomic profiles between mouse groups yielded broad changes in the relative levels of bacterial, fungal and mouse proteins. Many of the detected fungal proteins have been previously reported as a part of extracellular vesicles and having immunomodulating properties. Changes in the levels of mouse proteins derived from the small intestine impacted essential cellular pathways, including lipid metabolism and apoptosis. The results show how fungal colonization impacts the host proteome and suggest an influence on the host final cellular phenotype.
Project description:The goals of this study were to investigate whether two anesthesia regimens, with and without N2O, and bacterial colonization influence respiratory complications after major abdominal surgery for cancer.