Project description:Necrotizing enterocolitis (NEC) is an acute and life-threatening gastrointestinal disorder afflicting preterm infants, which is currently unpreventable. Fecal microbiota transplantation (FMT) is a promising preventative therapy, but potential bacterial infection raise concern. Removal of bacteria from donor feces may reduce this risk while maintaining the NEC-preventive effects. We aimed to assess preclinical efficacy and safety of bacteria-free fecal filtrate transfer (FFT). Using fecal material from healthy suckling piglets, we administered FMT rectally, or cognate FFT either rectally or oro-gastrically to formula-fed preterm, cesarean-delivered piglets as a model for preterm infants, We compared gut pathology and related safety parameters with saline controls, and analyzed ileal mucosal transcriptome to gauge the host e response to FMT and FFT treatments relative to control. Results showed that oro-gastric FFT prevented NEC, whereas FMT did not perform better than control. Moreover, FFT but not FMT reduced intestinal permeability, whereas FMT animals had reduced body weight increase and intestinal growth. Global gene expression of host mucosa responded to FMT but not FFT with increased and decreased bacterial and viral defense mechanisms, respectively. In conclusion, as preterm infants are extremely vulnerable to enteric bacterial infections, rational NEC-preventive strategies need incontestable safety profiles. Here we show in a clinically relevant animal model that FFT, as opposed to FMT, efficiently prevents NEC without any recognizable side effects. If translatable to preterm infants, this could lead to a change of practice and in turn a reduction in NEC burden.
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: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.
Project description:We procured PBMCs whole blood from five HC preterm infants and five preterm infants with BPD. PBMCs were extracted using a density gradient centrifugation method. Initially, 10ml of peripheral blood was mixed with an equal volume of physiological saline, then carefully layered onto Ficoll solution (T10124, from Shangbao Biotech Co., Ltd., Shanghai). After centrifugation at 2,000 rpm for 20 minutes, the cells stratified due to differences in density, with PBMCs positioned between the red blood cells and plasma. Subsequently, the intermediate layer containing PBMCs was gently collected, washed several times with physiological saline to remove residual medium and red blood cells, and finally, PBMCs were isolated and collected through centrifugation.
Project description:Necrotizing enterocolitis (NEC), a severe gut disorder in preterm infants, is difficult to predict due to poor specificity and sensitivity of clinical signs and biomarkers. Using preterm piglets as a model, we hypothesized that early development of NEC affects blood gene expression, potentially related to early systemic immune responses. In this animal model, variable severity of gut NEC lesions were detected in 5d-old piglets with limited clinical signs. NEC (n=20) and control piglets (CON, n=19) were analyzed for whole blood transcriptome, revealing 344 differentially expressed genes (DEGs) between NEC and CON piglets. Co-expression network analyses and qPCR suggested AOAH, FKBP5, PAK2 as three NEC-specific genes associated with severe gut lesions. These results suggest that whole blood gene expressions are affected in preterm piglets when clinical symptoms of NEC are minimal. Blood transcriptome may be a novel tool to identify early biomarkers of NEC.
Project description:Most hospitalized preterm infants receive antibiotics (AB) in the first days of life to treat or prevent systemic infections. Short-term, early AB treatment may also prevent against the microbiota-dependent serious gut disorder, necrotising enterocolitis (NEC). However, it remains a challenge to predict or early detection of NEC in the first weeks of life and few diagnostic markers exist. Using preterm piglets as models for infants, we hypothesised that proteomic profiling could be used to identify new early plasma biomarkers of NEC with or without prior AB treatment. Preterm newborn pigs were treated with saline (CON) or antibiotics (ampicillin, gentamicin, and metronidazole), given enterally (ENT) or parenterally (PAR), and fed formula for four days to induce NEC. The gut was collected for scoring of NEC lesions and blood was collected for haematology and plasma proteomics
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:We conducted a prospective cohort study with independent Discovery and Validation cohorts, to formulate predictive biomarkers for Bronchopulmonary Dysplasia in extremely preterm infants. Tracheal aspirate samples were collected at birth from extremely preterm infants. Exosomes were extracted from tracheal aspirates and total RNA was extracted from these exosomes from individual samples. miRNA profiling for all ~ 800 miRNAs was conducted on each sample by nanostring platform. This study found that a distinct airway exosomal miRNA sigrature at birth (decreased miR 876-3p) predicts future development of severe Bronchopulmonary Dysplasia in extremely preterm infants.
Project description:Preterm infants are highly susceptible to sustained lung inflammation, which may be triggered by exposure to multiple environmental cues such as supplemental oxygen (O2) and infections. The underlying mechanisms are still poorly understood. The hypothesis of this study is that dysregulated macrophage activation is a key feature leading to inflammation-mediated development of bronchopulmonary dysplasia (BPD) in preterm infants.
Cord blood samples of preterm infants (n=14) and term infants (n=19) as well as peripheral blood from healthy adults (n=17) were collected. Age-dependent differences in immune responses of monocyte-derived Mä from preterm infants were characterized and compared to term infants and adults after lipopolysaccharide (LPS) exposure.