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:Intra-amniotic infection, the invasion of microbes into the amniotic cavity resulting in an inflammatory process, is a clinical condition that can lead to adverse pregnancy outcomes for the mother and fetus as well as severe long-term neonatal morbidities. Despite much research focused on the consequences of intra-amniotic infection, there is still little knowledge about the functional roles of innate immune cells that respond to invading microbes. In the current study, we performed RNA sequencing of sorted neutrophils and monocytes/macrophages from amniotic fluid from women with intra-amniotic infection to determine the transcriptomic differences between these innate immune cells. Further, we sought to identify specific transcriptomic pathways that were significantly altered by the maternal or fetal origin of amniotic fluid neutrophils and monocytes, the presence of a severe fetal inflammatory response, and pregnancy outcome (i.e. preterm or term delivery). We showed that significant transcriptomic differences exist between amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection that are indicative of the distinct roles these cells play. We also found that amniotic fluid monocytes/macrophages of fetal origin display impaired ability to clear out microbes invading the amniotic cavity compared to those of maternal origin. Notably, we demonstrate that the transcriptomic changes in amniotic fluid monocytes/macrophages are heavily associated with the severity of the fetal inflammatory response, suggesting that the trafficking of fetal neutrophils throughout the umbilical cord is partially modulated by monocytes/macrophages in the amniotic cavity. Finally, we show that amniotic fluid neutrophils and monocytes/macrophages from preterm deliveries display enhanced transcriptomic activity compared to those from term deliveries, highlighting the protective role of these innate immune cells in this vulnerable period. Collectively, these findings demonstrate the underlying complexity of local innate immune responses in women with intra-amniotic infection, and provide new insights into the functions of amniotic fluid neutrophils and monocytes in the amniotic cavity.
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:Uterine stretch is thought to induce preterm labor in women with twin and higher order pregnancies, but the pathophysiology remains unclear. We investigated the pathogenesis of stretch-induced preterm birth for the first time in a pregnant nonhuman primate model. Eleven chronically catheterized pregnant monkeys (Macaca nemestrina) at 118-125 days gestation (term=172 days) received either: 1) inflation of intra-amniotic balloons (N=6) or 2) saline inoculation (N=5). Cesarean section and fetal necropsy was performed due to preterm labor or to collect tissues, except in one case where the animal delivered spontaneously, reducing samples for microarray analysis to ten (five stretch and five control animals). Amniotic fluid and maternal plasma were analyzed for multiple cytokines and prostaglandins using Luminex, enzyme-linked immunosorbent assay and Analysis of Covariance. Ribonucleic acid was extracted from the myometrium in the lower uterus at Cesarean section and analyzed by microarray and quantitative reverse transcriptase polymerase chain reaction.
Project description:The objective of this study was to identify the tissue expression patterns and biological pathways enriched in term amniotic fluid cell-free fetal RNA by comparing functional genomic analyses of term and second-trimester amniotic fluid supernatants. There were 2,871 significantly differentially regulated genes. In term amniotic fluid, tissue expression analysis showed enrichment of salivary gland, tracheal, and renal transcripts as compared with brain and embryonic neural cells in the second trimester. Functional analysis of genes upregulated at term revealed pathways that were highly specific for postnatal adaptation such as immune function, digestion, respiration, carbohydrate metabolism, and adipogenesis. Inflammation and prostaglandin synthesis, two key processes involved in normal labor, were also activated in term amniotic fluid.
Project description:The objective of this study was to identify the tissue expression patterns and biological pathways enriched in term amniotic fluid cell-free fetal RNA by comparing functional genomic analyses of term and second-trimester amniotic fluid supernatants. There were 2,871 significantly differentially regulated genes. In term amniotic fluid, tissue expression analysis showed enrichment of salivary gland, tracheal, and renal transcripts as compared with brain and embryonic neural cells in the second trimester. Functional analysis of genes upregulated at term revealed pathways that were highly specific for postnatal adaptation such as immune function, digestion, respiration, carbohydrate metabolism, and adipogenesis. Inflammation and prostaglandin synthesis, two key processes involved in normal labor, were also activated in term amniotic fluid. This was a prospective whole genome microarray study comparing eight amniotic fluid samples collected from eight women at term who underwent prelabor cesarean delivery and eight second-trimester amniotic fluid samples from routine amniocenteses. A functional annotation tool was used to compare tissue expression patterns in term and second-trimester samples. Pathways analysis software identified physiologic systems, molecular and cellular functions, and upstream regulators that were significantly overrepresented in term amniotic fluid.
Project description:The goal of the experiment was to uncover novel TTTS biomarkers using microarray gene expression analysis of cell free fetal RNA from the amniotic fluid of TTTS-affected and non-affected pregnant women.
Project description:Transcriptomic profiling is a crucial tool for understanding growth, development, behavior and predisposition to diseases and the development of health biomarkers. Here, we demonstrate the feasibility of transcriptomic assessment of cell-free fetal RNA in vervet monkey amniotic fluid supernatant (AFS).
Project description:Objective: Amniotic fluid (AF) is a proximal fluid to the fetus containing higher amounts of cell-free fetal RNA/DNA than maternal serum, thereby making it a promising source for novel biomarker discovery of fetal development and maturation. Our aim was to compare AF transcriptomic profiles at different time points in pregnancy to demonstrate unique genetic signatures that would serve as potential biomarkers indicative of fetal maturation. Methods: We isolated AF RNA from 16 women at different time points in pregnancy: 4 from 18-24 weeks, 6 from 34-36 weeks, and 6 from at 39-40 weeks. RNA-sequencing was performed on cell-free RNA. Gene expression and splicing analyses were performed in conjunction with cell-type and pathway inference. Results: Sample-level analysis at different time points in pregnancy yielded a strong correlation with cell types found in the intrauterine environment and fetal respiratory, digestive and external barrier tissues of the fetus, using high-confidence cellular molecular markers. While some genes and splice variants were present throughout pregnancy, an abundant number of transcripts were uniquely expressed at different time points in pregnancy and associated with distinct fetal co-morbidities (respiratory distress and gavage feeding), indicating fetal immaturity. Conclusions: The AF transcriptome exhibits unique cell- and organ-selective expression patterns at different time points in pregnancy that can potentially identify fetal organ maturity and predict neonatal morbidity. Developing novel biomarkers indicative of the maturation of multiple organ systems can improve upon our current methods of fetal maturity testing which focus solely on the lung, and better inform obstetrical decisions regarding delivery timing.