Project description:Preterm infants are susceptible to neonatal inflammatory/infective diseases requiring drug therapy. The present study hypothesized that mRNA expression in the blood may be modulated by signaling pathways during treatment. The current study aimed to explore changes in global gene expression in the blood from preterm infants with the objective of identifying patterns or pathways of potential relevance to drug therapy. The infants involved were selected based on maternal criteria indicating increased risk for therapeutic intervention. Global mRNA expression was measured in 107 longitudinal whole blood samples using Affymetrix Human Genome U133 Plus 2.0 arrays; samples were obtained from 20 preterm infants. Unsupervised clustering revealed a distinct homogeneous gene expression pattern in 13 samples derived from seven infants undergoing continuous oxygen therapy. At these sampling times, all but one of the seven infants exhibited severe drops in peripheral capillary saturation levels below 60%. The infants were reoxygenated with 100% inspired oxygen concentration. The other samples (n=94) represented the infants from the cohort at time points when they did not undergo continuous oxygen therapy. Comparing these two sets of samples identified a distinct gene expression pattern of 5,986 significantly differentially expressed genes, of which 5,167 genes exhibited reduced expression levels during transient hypoxia. This expression pattern was reversed when the infants became stable, i.e., when they were not continuously oxygenated and had no events of hypoxia. To identify signaling pathways involved in gene regulation, the Database for Annotation, Visualization and Integrated Discovery online tool was used. Mitogen activated protein kinases, which are normally induced by oxidative stress, exhibited reduced gene expression during hypoxia. In addition, nuclear factor erythroid 2 related factor 2 antioxidant response element target genes involved in oxidative stress protection were also expressed at lower levels, suggesting reduced transcription of this pathway. The findings of the present study suggest that oxidative stress dependent signaling is reduced during hypoxia. Understanding the molecular response in preterm infants during continuous oxygenation may aid in refining therapeutic strategies for oxygen therapy.
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.
Project description:It is unclear why preterm birth increases risk of cardiovascular disease later in life. Studies in mice indicate excess oxygen used to treat preterm infants causes pulmonary hypertension, cardiac failure, and shortens lifespan. We previously reported neonatal hyperoxia causes pulmonary hypertension in aged mice as defined pathologically by pulmonary capillary rarefaction, dilation of pulmonary arterioles and veins, right ventricular hypertrophy, and reduced lifespan. Here, affymetrix gene arrays were used to identify early transcriptional changes in lungs of young adult mice exposed to room air or 100% oxygen between postnatal days 0-4.
Project description:It is unclear why preterm birth increases risk of cardiovascular disease later in life. Studies in mice indicate excess oxygen typically used to treat preterm infants causes pulmonary hypertension, cardiac failure, and shortens lifespan. We previously reported neonatal hyperoxia causes pulmonary hypertension in aged mice as defined pathologically by pulmonary capillary rarefaction, dilation of pulmonary arterioles and veins, right ventricular hypertrophy, and reduced lifespan. These changes were preceded by a pronounced growth inhibition of cardiomyocytes lining the pulmonary vein and extending into the left atria, resulting in diastolic heart failure as the mice aged. To identify transcriptional changes by which hyperoxia suppresses proliferation of these cardiomyocytes, newborn mice were exposed to room air or 100% oxygen between birth and postnatal day 4. RNA was then isolated from atria of 3 room air and 4 hyperoxia-exposed mice and used to probe Affymetrix mouse array 430 versus 2.0
Project description:Mesenchymal stem cells (MSCs) hold great therapeutic potential in morbidities associated with preterm birth. However, the molecular expressions of hMSCs in preterm birth infants have not been systematically evaluated. In this study, we presented the dual-omics analyses of umbilical cord (UC) derived hMSCs to identify the dysregulated cellular functions. Materials and methods: The UC-MSCs were collected from 10 full-term and 8 preterm birth infants for transcriptomics and proteomics analyses by using microarray and iTRAQ-based proteome profiling. The integrative analysis of dual-omics data discovered 5,615 commonly identified genes/proteins of which 29 genes/proteins showed consistent up- or down-regulation in preterm birth. The Gene Ontology analysis revealed that the biological processes of mitochondrial translation and cellular response to oxidative stress were mainly enriched in 290 differential expression proteins (DEPs) while the 421 differential expression genes (DEGs) were majorly involved in secondary alcohol metabolic process, cellular response to stress, and mitotic cell cycle in preterm birth. Besides, we identified a 13-protein module involving CUL2 and CUL3, which plays an important role in cullin-RING-based ubiquitin ligase complex, as potential mechanism for preterm birth. The dual-omics data not only provided new insights to the molecular mechanism but also to identify panel of candidate markers associated with preterm birth.
Project description:This study measured the cytokine, cellular and transcriptomic response to RSV and compared these between preterm and term infants CBMC responses
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:Analysis of influenza A and respiratory synctial virus infections in cultured nasal epithelial cells at the air-liquid interface (ALI) of adult, term, and preterm infants.