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:Preterm birth is often predisposed by chorioamnionitis (CA) and CA affects the fetal gut and lungs via intra-amniotic (IA) inflammation, thus accentuating the proinflammatory effects of preterm birth. It is not known if IA inflammation also affects other perfusion-sensitive organs (e.g., kidneys) before and after preterm birth. Using preterm pigs as model for preterm infants, we hypothesized that CA induces fetal and neonatal renal dysfunctions that can intially be detected via plasma proteome, partly explaining the frequent renal dysfunction in preterm infants. Fetal pigs (88% gestation) were given an IA dose of lipopolysaccharide (LPS, 1 mg/kg, n=28), delivered preterm by cesarean section three days later, and compared with controls (CON, n=26) at birth and postnatal day five. Plasma proteome and protein markers of inflammatory pathways were evaluated.
Project description:We hypothesized that the immature pig intestine would be highly sensitive to gene methylation changes in the immediate prenatal and neonatal periods. We performed a Reduced Representation Bisulfite Sequencing (RRBS) to assess the DNA methylation differences occurring during the last 10 days prenatally (PN, 0d-term vs. 0d-preterm), neonatally after 4 days (NN, 4d-preterm vs. 0d-preterm) and after NEC development (4d-preterm-NEC vs. 4d-preterm) in pigs (each group n=2-3). Differentially methylated gene regions (DMRs) between the groups were identified, subjected to KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and selected genes were chosen for further validation of gene expression levels by RT-PCR (n= 6 for each group). Consistent with the need to increase expression of many intestinal genes in the perinatal period, methylation levels of most genes decreased during the prenatal and neonatal periods. We identified four intestinal genes (CYP2W1, GPR146, TOP1MT, CEND1), related to intestinal metabolism, that were significantly hyper-methylated in their promoter CGIs, and transcriptionally down-regulated in the 4 d-old preterm pigs. This down-regulation of intestinal metabolism may predispose to intestinal dysfunction and NEC. The first enteral feeds and bacterial colonization are critical factors for NEC sensitivity and it remains to be investigated whether these factors affect intestinal gene methylation and thereby predispose to, or prevent from, disease more long term.
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.
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.
Project description:Obese and lean pig breeds showed obvious phenotypic variations and physiological differences in skeletal muscle growth. Prenatal muscle development programs postnatal performance. In this study we initially conducted full transcriptional profiling of prenatal skeletal muscle from Tongcheng pigs (obese) and Landrace pigs (lean) at 33, 65 and 90 days post coitus (dpc), using long serial analysis of gene expression (LongSAGE). We subsequently sequenced 317,115 LongSAGE tags and identified 1400 and 1201 differentially expressed transcripts that showed eight expression patterns for Tongcheng and Landrace, respectively. These two breeds had more significant differences in their gene expression profiles at 65 than that at 33 and 90 dpc. We also identified 532, 653 and 459 transcripts that were differentially expressed at 33, 65 and 90 dpc between the two breeds, respectively. The cellular function of the differentially expressed transcripts that matched annotated genes revealed that each stage had a uniquely altered profile between the two breeds in various functional categories including muscle fiber constitute and contraction, apoptosis, protein synthesis, and signalling transduction. Our results suggest that skeletal muscle development potentially has a greater lag in its growth rate at 33-65 dpc in Tongcheng pigs when compared with their Landrace counterparts. Our analyses therefore not only will provide valuable resources in the further identification of candidate genes for meat production traits, but also assist in the elucidation of the development of prenatal skeletal muscle in pigs and other vertebrates. Keywords: comparative transcriptome analysis
Project description:In this study, we tested if miRNAs are altered in amygdala and ventral striatum as a consequence of prenatal ethanol exposure and/or social enrichment. miRNA samples from 72 male and female adolescent rats were analyzed by RNA-Seq analysis and Affymetrix miRNA arrays. Several miRNAs showed significant changes due to prenatal ethanol exposure or social enrichment in one or both brain regions. Some of the miRNA changes caused by ethanol were reversed by social enrichment. The top predicted gene targets of these miRNAs were mapped and subjected to pathway enrichment analysis. We also directly examined the evidence for modulation of target mRNAs in whole transcriptome microarray data from the same rats. Among the pathways most strongly affected were p53, CREB, Glutamate and GABA signaling. Together, our data suggest a number of novel epigenetic mechanisms for social enrichment to reverse the effects of ethanol exposure. A total of 48 samples were analyzed by small RNA-Sequencing using RNA purified from 2 brain regions (amygdala and ventral striatum) of postnatal day 42 Long Evans rats. 3 replicate sequencing runs were performed for each gender within 4 different treatment groups (prenatal ethanol or prenatal saline exposed; postnatal socially-enriched or non-enriched environment)
Project description:In this study, we tested if miRNAs are altered in amygdala and ventral striatum as a consequence of prenatal ethanol exposure and/or social enrichment. miRNA samples from 72 male and female adolescent rats were analyzed by RNA-Seq analysis and Affymetrix miRNA arrays. Several miRNAs showed significant changes due to prenatal ethanol exposure or social enrichment in one or both brain regions. Some of the miRNA changes caused by ethanol were reversed by social enrichment. The top predicted gene targets of these miRNAs were mapped and subjected to pathway enrichment analysis. We also directly examined the evidence for modulation of target mRNAs in whole transcriptome microarray data from the same rats. Among the pathways most strongly affected were p53, CREB, Glutamate and GABA signaling. Together, our data suggest a number of novel epigenetic mechanisms for social enrichment to reverse the effects of ethanol exposure. A total of 48 Rat ST Gene 1.0 GeneChips and 48 miRNA 2.0 GeneChips were run on RNA purified from 2 brain regions (amygdala and ventral striatum) of postnatal day 42 Long Evans rats. 3 replicate arrays were run for each gender within 4 different treatment groups (prenatal ethanol or prenatal saline exposed; postnatal socially-enriched or non-enriched environment)