Project description:Necrotizing Enterocolitis (NEC) is an inflammation causing injury to the bowel in newborns. This project uses a rodent model that mimics the intestinal pathological changes seen in NEC to study the effect of formula feeding and hypoxia on NEC development
Project description:Necrotizing Enterocolitis (NEC) is an inflammation causing injury to the bowel in newborns. This project uses a rodent model that mimics the intestinal pathological changes seen in NEC to study the effect of formula feeding and hypoxia on NEC development Keywords: time series, diet, hypoxia
Project description:Major risk factors for necrotizing enterocolitis (NEC) are formula feeding and prematurity, however, their pathogenic mechanisms are unknown. We found that insufficient arginine/nitric oxide synthesis limits blood flow in the intestinal microvasculature, leading to hypoxia, mucosa damage and NEC in the premature intestine after formula feeding. Formula feeding led to increased intestinal hypoxia in pups at postnatal day 1(P1) and P5, but not in more mature pups at P9. Accordingly, blood flow in the intestinal microvasculature increased after formula feeding only in P9 pups. mRNA profiling revealed that regulators of arginine/nitric oxide synthesis are at higher levels in endothelial cells of the intestine of P9 than P1 pups. Importantly, arginine supplementation increased intestinal microvasculature blood flow, and prevented NEC, whereas an arginine antagonist exacerbated NEC. Our results suggest that balancing intestinal oxygen demand and supply in the premature intestine by modulating arginine/nitric oxide could be used to prevent NEC.
Project description:Necrotizing enterocolitis (NEC), a serious gastrointestinal disease that afflicts 5-10% of preterm infants, often progresses rapidly from mild food intolerance into extensive haemorrhage, inflammation and necrosis. Events leading to NEC have remained poorly defined. Similar disease characteristics are observed in preterm pigs 24-48 h after feeding formula. Using this model, we aimed to characterize the temporal development of NEC, and describe the functional and immunological response of the preterm intestine preceding NEC. Keywords: time course
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:Necrotizing enterocolitis (NEC), a serious gastrointestinal disease that afflicts 5-10% of preterm infants, often progresses rapidly from mild food intolerance into extensive haemorrhage, inflammation and necrosis. Events leading to NEC have remained poorly defined. Similar disease characteristics are observed in preterm pigs 24-48 h after feeding formula. Using this model, we aimed to characterize the temporal development of NEC, and describe the functional and immunological response of the preterm intestine preceding NEC. Keywords: time course Pigs from treatment groups TPN (n=5), and 8 h (n=5) and 24 h (n=5-6) FORM and COLOS were randomly selected for microarray analysis. Equal amounts of total distal small intestinal RNA from all pigs was 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 and eight different array control oligonucleotides (ArrayControl; Ambion, Nærum, Denmark). The immunologically relevant 60-70mer oligonucleotide probes represent interferons and interleukins (and receptors), chemokines (and receptors), acute phase proteins, apoptosis-related factors and sequences with relevance to Toll-like receptors and their intracellular signalling pathways.
Project description:The devastation caused by necrotizing enterocolitis (NEC) has only continued to claim the lives of infants despite advances in neonatal medicine. To address the acute, and often severe, intestinal epithelial damage caused by NEC, therapeutics are needed that directly target epithelial recovery and cellular regeneration processes. Amniotic fluid and its derivatives have shown therapeutic benefit for NEC though these elements remain difficult to obtain. We therefore investigated the capacity of a decellularized human placental extract (HPE) comparable to amniotic fluid for its ability to prevent against and enhance recovery from NEC using in vitro and in vivo models. Healing responses of hypoxia or scratch-wound injured primary neonatal porcine ileal epithelial cells following HPE application were analyzed. In vivo, NEC was induced in neonatal piglets through a combination of preterm delivery and formula feeding. Treated piglets received enteral HPE while control were nil per os prior to formula initiation. In vitro, HPE treatment accelerated scratch closure and increased proliferating cell number, without enhanced tight junction recovery following hypoxia. In vivo, HPE treatment increased weight gain, decreased macroscopic and histological damage, and increased ileal crypt epithelial cell proliferation. Transcriptomic analysis of monolayer cultures treated with HPE was undertaken after observation of similar effects in both in vitro and in vivo platforms. Increases in shared gene pathways associated with epithelial wound healing, proliferation, and migration were identified including members of the Wnt family. In sum, these findings suggest that HPE can enhance the reparative capacity of neonatal epithelium in the context of NEC.
Project description:Neonatal necrotizing enterocolitis (NEC) is a deadly and unpredictable gastrointestinal disease, for which no biomarkers exist. We aimed to describe the methylation patterns in stool and colon from infants with NEC.
Project description:Necrotizing enterocolitis (NEC) is the most common and lethal gastrointestinal disease affecting preterm infants. NEC develops suddenly and is characterized by gut barrier destruction, an inflammatory response, intestinal necrosis and multi-system organ failure. There is currently no method for early NEC detection, and the pathogenesis of NEC remains unclear.