Project description:Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis
Project description:Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis Pigs from each treatment group (COLOS, n=4; FORM, n=6; and AF, n=7) were randomly selected for microarray analysis of frozen distal small intestine samples. The FORM group was further divided into formula-fed healthy pigs (F-HEA, n=3) and formula-fed NEC pigs (F-NEC, n=3) in order to compare sick versus healthy formula fed pigs. Equal amounts of total distal small intestinal RNA from all pigs were pooled to make the reference sample. Samples and reference pool were labelled with Oyster 550 and 650, respectively. The in-house spotted porcine oligonucleotide microarray version 4 (POM4) is a low density microarray consisting of 384 different oligonucleotide probes representing more than 200 different immune related genes.
Project description:Preterm infants are highly susceptible to late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) but specific biomarkers for diagnosis and effective treatment are lacking. Neutrophil extracellular traps (NETs) are related to sepsis in adults but not investigated in infant conditions. This is the first proteome study to document that circulating NETs are involved in neonatal LOS and NEC. cfDNA and NET proteins may provide new potential diagnostic markers for these diseases.
Project description:91 preterm infant gut metaproteomes measured in technical duplicate using an eleven salt pulse 2D-LC-MS/MS method. Samples represent 17 preterm infants over the first several weeks of life, of which 6 preterm infants eventually developed necrotizing enterocolitis.
Project description:Necrotizing enterocolitis (NEC) is the most frequent life-threatening gastrointestinal disease experienced by premature infant occuring in neonatal intensive care units. NEC is associated with severe intestinal inflammation, intestinal perforation leading to mortality. The challenge for neonatologists is to detect early clinical manifestations of NEC. Therefore, one of the strategies to prevent or treat NEC would be to develop an early diagnostic tool allowing identification of preterm infants either at risk of developing NEC or at the onset of the disease. Illumina’s deep sequencing technology (RNA-seq) was used to establish the gene expression profile between resected ileal healthy preterm (control, n=5) and NEC diagnosed preterm infant (NEC, n=9) and analyzed by IPA Core analysis system. IPA analysis indicated that the most significant functional pathways overrepresented in NEC neonates were associated with innate immune functions, such as altered T and B cell signaling, B cell development, and the role of pattern recognition receptors in recognition of bacteria and viruses. Among genes that were strongly modulated in NEC neonates, we observed a high degree of similarity with those linked to the development of IBD. By comparing gene expression patterns between NEC and Crohn’s disease, we identified several new potential protein targets for helping to predict and/or diagnose NEC in preterm infant. Gene expression profile revealed an uncontrolled innate immune response in the intestine of NEC neonates. Moreover, comparative analysis between NEC and Crohn’s disease evidenced high degree of similarity between these two inflammatory diseases and allowed us to identify several new potential NEC biomarkers.
Project description:Bacillus Calmette–Guérin (BCG) vaccination immediately after birth provides overall protection against immune disorders in healthy infants. However, for vulnerable infants such as preterm or low birth weights, delayed BCG vaccination is usually recommended. The mechanism underlying this clinical application remains obscure. Here we reported that BCG vaccination abrogated the transitory appearance of immunosuppressive myeloid cells in neonatal mice, that is myeloid-derived suppressor cells (MDSCs) represented as the important immunoprotection against inflammatory diseases in early life. A combination of single-cell transcriptome, metabolite profiling, and functional analysis revealed that the upregulation of mTOR/HIF1a signaling and the enhanced glycolysis explained the underlying mechanism. Consequently, BCG vaccination significantly exacerbated the severity of necrotizing enterocolitis (NEC), a common clinical emergency primarily affecting preterm or low birth weight infants. Adoptive transfer of MDSCs or pharmalogical inhibition of glycolysis or mTOR signaling efficiently relieved the severity of NEC upon BCG vaccination. These observations suggest that BCG may diminish the protective mechanism of myeloid cells and enhances the susceptibility of NEC in vulnerable neonates.