Project description:“Dysbiosis" of the maternal gut microbiome, in response to environmental challenges such as infection, altered diet and stress during pregnancy, has been increasingly associated with abnormalities in offspring brain function and behavior. However, whether the maternal gut microbiome regulates neurodevelopment in the absence of environmental challenge remains unclear. In addition, whether the maternal microbiome exerts such influences during critical periods of embryonic brain development is poorly understood. Here we investigate how depletion, and selective reconstitution, of the maternal gut microbiome influences fetal neurodevelopment in mice. Embryos from antibiotic-treated and germ-free dams exhibit widespread transcriptomic alterations in the fetal brain relative to conventionally-colonized controls, with reduced expression of several genes involved in axonogenesis. In addition, embryos from microbiome-depleted mothers exhibit deficient thalamocortical axons and impaired thalamic axon outgrowth in response to cell-extrinsic guidance cues and growth factors. Consistent with the importance of fetal thalamocortical axonogenesis for shaping neural circuits for sensory processing, restricted depletion of the maternal microbiome from pre-conception through mid-gestation yields offspring that exhibit tactile hyposensitivity in select sensorimotor behavioral tasks. Gnotobiotic colonization of antibiotic-treated dams with a limited consortium of spore-forming bacteria indigenous to the gut microbiome prevents abnormalities in fetal brain gene expression, fetal thalamocortical axonogenesis and adult tactile sensory behavior associated with maternal microbiome depletion. Metabolomic profiling reveals that the maternal microbiota regulates levels of numerous small molecules in the maternal serum as well as the brains of fetal offspring. Select microbiota-dependent metabolites – trimethylamine N-oxide, 5-aminovalerate, imidazole propionate, and hippurate – sufficiently promote axon outgrowth from fetal thalamic explants. Moreover, maternal supplementation with the metabolites during early gestation abrogates deficiencies in fetal thalamocortical axons and prevents abnormalities in tactile sensory behavior in offspring from microbiome-depleted dams. Altogether, these findings reveal that the maternal gut microbiome promotes fetal thalamocortical axonogenesis and select tactile sensory behaviors in mice, likely by signaling of microbially modulated metabolites to neurons in the developing brain.
Project description:Both the fetus and the mother who are involved in maternal anti-fetal rejection during pregnancy show distinct alterations in the peripheral blood transcriptome Total RNA isolated from umbilical cord blood and maternal blood was compared between cases without (Normal) and with maternal anti-fetal rejection (FIRS2) using whole genome DASL assay.
Project description:We analyzed the small RNA composition of mouse placenta/decidua to determine whether there are specific differences in small RNAs during fetal development and in response to maternal immune activation.
Project description:<p>Myostatin (gene symbol: Mstn) is an autocrine and paracrine inhibitor of muscle growth. Pregnant mice with genetically reduced levels of myostatin give birth to offspring with greater adult muscle mass and bone biomechanical strength. However, maternal myostatin is not detectable in fetal circulations. Fetal growth is dependent on the maternal environment, and the provisioning of nutrients and growth factors by the placenta. Thus, this study examined the effect of reduced maternal myostatin on maternal and fetal serum metabolomes, as well as the placental metabolome. Fetal and maternal serum metabolomes were highly distinct, which is consistent with the role of the placenta in creating a specific fetal nutrient environment. There was no effect from myostatin on maternal glucose tolerance or fasting insulin. In comparisons between pregnant control and Mstn+/− mice, there were more significantly different metabolite concentrations in fetal serum, at 50, than in the mother’s serum at 33, confirming the effect of maternal myostatin reduction on the fetal metabolic milieu. Polyamines, lysophospholipids, fatty acid oxidation, and vitamin C, in fetal serum, were all affected by maternal myostatin reduction.</p>
Project description:Both the fetus and the mother who are involved in maternal anti-fetal rejection during pregnancy show distinct alterations in the peripheral blood transcriptome
Project description:During pregnancy, cells from each fetus travel into the maternal circulation and organs, resulting in the development of microchimerism. Identification of the cell types in this microchimeric population would permit better understanding of possible mechanisms by which they affect maternal health. However, comprehensive analysis of fetal cells has been hampered by their rarity. In this study, we sought to overcome this obstacle by combining flow cytometry with multidimensional gene expression microarray analysis of fetal cells isolated from the murine maternal lung during late pregnancy. Fetal cells were collected from the lungs of pregnant female mice. cDNA was amplified and hybridized to gene expression microarrays. The resulting fetal cell core transcriptome was interrogated using multiple methods including Ingenuity Pathway Analysis, the BioGPS gene expression database, principal component analysis, the Eurexpress gene expression atlas and primary literature. Here we report that small numbers of fetal cells can be flow sorted from the maternal lung, facilitating discovery-driven gene expression analysis. We additionally show that gene expression data can provide functional information about the fetal cells. Our results suggest that fetal cells in the murine maternal lung are a mixed population, consisting of trophoblasts, mesenchymal stem cells and cells of the immune system. The detection of trophoblasts and immune cells in the maternal lung may facilitate future mechanistic studies related to the development of immune tolerance and pregnancy-related complications, such as preeclampsia. Furthermore, the presence and persistence of mesenchymal stem cells in maternal organs may have implications for long-term postpartum maternal health. Comprehensive gene expression microarray analysis of fetal cells isolated from the pregnant murine maternal lung. Seven individual replicates were performed.
Project description:Activation of the maternal immune system during pregnancy affects fetal development, which can increase in postnatal susceptibility to a range of diseases, including cardiovascular, metabolic and psychiatric disorders. During maternal immune activation (MIA), the maternal body must balance its ressources between mounting an immune response and investing resources into continued metabolism and growth, essentials for survival of the fetus and a successful pregnancy. How the placenta responds to MIA over time and how it can protect the fetus is not well understood, and neither are the fetal consequences of MIA. Here, we characterised the response to acute maternal lung inflammation across time in maternal and fetal organs, using a combination of omics, imaging and integrative computational analyses. We found that the placenta, unlike other maternal organs, did not react by a typical innate immune response, but instead induced genes associated with increased tissue integrity, likely to prevent fetal exposure to potential infections, and simultaneously reduced expression of growth-associated genes. Subsequently, a return to homeostasis was observed, with heightened expression of biosynthesis and endoplasmic reticulum (ER) stress genes. These responses likely protect the fetus from inflammation, as we observed no immune response in the fetal liver transcriptome. Instead, we observed metabolic adaptations in the fetus, including a release of docosahexaenoic acid (DHA) carrying metabolites, including triglyceride and phosphatidylcholine. Notably, DHA is crucial for fetal brain development. This metabolic response is likely a combination of the placental MIA response and temporary maternal fasting, caused by MIA-induced fever and lack of nutrient intake. Our study shows, for the first time, the integrated temporal and systemic response to LPS in lungs across maternal and fetal organs