Prenatal Exposure to Metals Alters the Placental Inflammatory Proteome in a Sex-Dependent Manner in Extremely Low Gestational Age Newborns
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ABSTRACT: Prenatal exposure to toxic metals is associated with altered placental function and adverse health outcomes. The underlying mechanisms linking in utero toxic metal exposures with later-in-life health remain unclear, though placental inflammation is posited as a potential driver. The aim of this study was to evaluate whether in utero metals presence is associated with sex-specific changes in placental protein expression. We hypothesized that sex-specific patterns of metal-associated placental protein expression would be observed, and metals presence would be positively associated with the altered expression of inflammation-associated pathways Using samples banked from the Extremely Low Gestational Age Newborn Study (ELGAN), umbilical cord tissue samples were analyzed via ICP-MS/MS for trace elements, and placental samples underwent a global untargeted proteomics analysis via LC-MS/MS. This work highlights the linkage between prenatal metals exposure and an altered placental proteome, revealing that metals in cord tissue were associated with largely distinct differences in placental protein expression, in a sexually-dimorphic manner.
International journal of molecular sciences 20231007 19
Prenatal exposure to toxic metals is associated with altered placental function and adverse infant and child health outcomes. Adverse outcomes include those that are observed at the time of birth, such as low birthweight, as well as those that arise later in life, such as neurological impairment. It is often the case that these adverse outcomes show sex-specific responses in relation to toxicant exposures. While the precise molecular mechanisms linking in utero toxic metal exposures with later-i ...[more]
Project description:Prenatal alcohol exposure (PAE) has previously been shown to alter fetal blood flow in utero and is also associated with placental insufficiency and intrauterine growth restriction (IUGR), suggesting an underlying connection between perturbed circulation and pregnancy outcomes. Here we show that a single exposure to ethanol in pregnant mice on gestational day 10 (GD10) by gavage attenuates umbilical cord blood flow transiently during gestation, explaining the observed IUGR, specifically decreased fetal weight, and morphometric indices of cranial growth. Moreover, RNAseq of the fetal portion of the placenta demonstrated that this single exposure has lasting transcriptomic changes, including upregulation of Tet3, which is associated with spontaneous abortion. Weighted gene co-expression network analysis (WGCNA) identified erythrocyte differentiation and homeostasis as important pathways associated with improved umbilical cord blood flow as gestation progresses. WGCNA also identified sensory perception of chemical stimulus/odorant and receptor activity as important pathways associated with cranial growth. Our data suggest that PAE perturbs the expression of placental genes relevant for placental hematopoiesis and environmental sensing, resulting in transient impairment of umbilical cord blood flow and subsequently, IUGR.
Project description:The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women. [I] We profiled whole antepartum (A), postpartum (P), and umbilical cord (U) blood samples from each of 9 mothers and their 10 newborns (1 set of twins, denoted as a and b after the sample names). [II] We also profiled plasma samples (A, P, and U) from three of those mothers to allow for a direct comparison between blood and plasma.
Project description:Embryonic and fetal development can be affected during gestation by exposure to xenobiotics that cross the placenta. Liquid crystal monomers (LCMs) are emerging contaminants commonly found in indoor environments; however, whether they can cross the placenta and affect placental development remains unexplored. Here, we developed an evaluation system that integrates human biomonitoring, uterine perfusion in pregnant rats, and placental cells. We found fourteen out of the fifty-six LCMs that were detected in maternal and cord serum samples from ninety-three healthy pregnant women, at median levels of 13.9 and 18.1 ng/mL, respectively. Subsequent exploration of in utero exposure in rats indicated that aromatic amino acid transporter 1 (SLC16A10) mediated transplacental transportation of the LCMs. Placental cells exposed to LCMs exhibited delayed placental development and reduced progesterone release. These findings showed that SLC16A10-mediated transplacental transportation of LCMs inhibits placental development and progesterone release, highlighting the importance of gestational exposure to emerging contaminants.
Project description:Allergy is one of the most common diseases among young children yet all factors that affect development of allergy remain unclear. In a small cohort of 65 children living in the same rural area of south-west Sweden, we have previously found that maternal factors, including prenatal diet, affect childhood allergy risk, suggesting that in utero conditions may be important for allergy development. Here, we studied if metabolites in the umbilical cord blood of newborns may be related to development of childhood allergy, accounting for key perinatal factors such as mode of delivery, birth order and sex. Umbilical cord blood plasma samples from 44 of the participants were analysed using gas chromatography-mass spectrometry metabolomics; allergy was diagnosed by specialised paediatricians at ages 18 months, 36 months and 8 years and included eczema, asthma, food allergy and allergic rhinoconjunctivitis. Nineteen cord blood metabolites were related to future allergy diagnosis though was no clear pattern of up- or downregulation of metabolic pathways. In contrast, perinatal factors birth order, sex and mode of delivery affected several energy and biosynthetic pathways, including glutamate and aspartic acid - histidine metabolism (p=0.004) and the tricarboxylic acid cycle (p=0.006) for birth order; branched chain amino acid metabolism (p=0.0009) and vitamin B6 metabolism (p=0.01) for sex; and glyoxylate and dicarboxylic acid metabolism (p=0.005) for mode of delivery. In conclusion, the cord blood metabolome includes individual metabolites that reflect lifestyle, microbial and other factors that may also be associated with future allergy diagnosis, and also reflects temporally close events/factors. Larger studies are required to confirm these associations, and perinatal factors such as birth order or siblings must be considered in future cord-blood metabolome studies.
Project description:Background: Maternal smoking during pregnancy is a major risk factor for adverse health outcomes. The main objective of the study was to assess the impact of in utero tobacco exposure on DNA methylation in children born at term with appropriate weight at birth. Methods: Twenty mother-newborn dyads, after uncomplicated pregnancies, in the absence of perinatal illness were included. All mothers were healthy with no cardiovascular risk factors, except for the associated risks among those mothers who smoked. Umbilical cord blood (for methylation arrays) and maternal peripheral venous blood (for cotine level measurement) were collected and an epigenome-wide association study was performed using a 450K epigenome-wide scan (Illumina Infinium HumanMethylation 450BeadChip) with adjustment to normalize the DNA methylation for data cell variability in whole blood. Results: The maternal plasmatic cotinine levels ranged from 10.70-115.40 ng/ml in the exposed group to 0-0.59 ng/ml in the non-exposed group. After adjusting for multiple comparisons in 427102 probes, statistically significant differences for 31 CpG sites, associated to 25 genes were observed. There was a greater than expected proportion of statistically-significant loci located in CpG islands (FisherM-bM-^@M-^Ys exact test, p=0.029) and of those CpG islands, 90.3% exhibit higher methylation levels in the exposed group. The most striking and significant CpG site, cg05727225, is located in the chromosome 11p15.4, within the adrenomedullin gene. Conclusions: In utero tobacco exposure, even in the absence of fetal growth restriction, may alter the epigenome, contributing to global DNA hypomethylation. Therefore, DNA status can be used as a biomarker of prenatal insults. Considering the possibility to reverse epigenetic modifications, a window of opportunity exists to change the programmed chronic disease. Twenty mother-newborn dyads, after uncomplicated pregnancies, in the absence of perinatal illness were included. All mothers were healthy with no cardiovascular risk factors, except for the associated risks among those mothers who smoked. Umbilical cord blood were collected and an epigenome-wide association study was performed using a 450K epigenome-wide scan (Illumina Infinium HumanMethylation 450BeadChip) with adjustment to normalize the DNA methylation for data cell variability in whole blood.
Project description:Maternal and fetal monocytes and tissue macrophages (decidual macrophages, Hofbauer cells) at the feto-maternal interface have different methylome. Paired and balanced design. We compared maternal blood monocytes (MB) vs. cord blood monocytes (CB), maternal blood monocytes (MB) vs. decidual macrophages (Deci), cord blood monocytes (CB) vs placental macrophages (villi) and decidual macrophages (Deci) vs. placental macrophages (villi).
Project description:DNA methylation profiling of CD34 positive cells derived from cord blood at birth following prenatal stress The groups consist of 8 individuals with low levels of prenatal stress (control) and 10 individuals with high levels of prenatal stress (stress)
Project description:Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed antidepressant drugs in pregnant women. Given that SSRIs can cross the placental and blood-brain barriers, these drugs potentially affect serotonergic neurotransmission and neurodevelopment in the fetus. Although no gross SSRI-related teratogenic effect has been reported, infants born following prenatal exposure to SSRIs have a higher risk for various behavioral abnormalities. Therefore, we examined the effects of prenatal fluoxetine, the most commonly prescribed SSRI, on social and cognitive behavior in mice. Intriguingly, chronic in utero fluoxetine treatment impaired working memory and social novelty recognition in adult males with augmented spontaneous inhibitory synaptic transmission onto the layer 5 pyramidal neurons in the medial prefrontal cortex (mPFC). Moreover, fast-spiking interneurons in the layer 5 mPFC exhibited enhanced basal intrinsic excitability, augmented serotonin-induced neuronal excitability, and increased inhibitory synaptic transmission onto the layer 5 pyramidal neurons due to augmented 5-HT2A receptor (5-HT2AR) signaling. More importantly, the observed behavioral deficits of in utero fluoxetine-treated mice could be reversed by acute systemic application of 5-HT2AR antagonist. Taken together, our findings support the notion that alterations in serotonin-mediated inhibitory neuronal modulation result in reduced cortical network activities and cognitive impairment following prenatal exposure to SSRIs.
Project description:The Biomarkers of Exposure to ARsenic (BEAR) pregnancy cohort in Gómez Palacio, Mexico was recently established to better understand the impacts of prenatal exposure to inorganic arsenic (iAs). In this study, we examined a subset (n = 40) of newborn cord blood samples for microRNA (miRNA) expression changes associated with in utero arsenic exposure. Levels of iAs in maternal drinking water (DW-iAs) and maternal urine were assessed. Levels of DW-iAs ranged from below detectable values to 236 µg/L (mean = 51.7 µg/L). Total arsenic in maternal urine (U-tAs) was defined as the sum of iAs and its monomethylated and dimethylated metabolites (MMAs and DMAs, respectively) and ranged from 6.2 to 319.7 µg/L (mean = 64.5 µg/L). Genome-wide miRNA expression analysis of cord blood revealed 12 miRNAs with increasing expression associated with U-tAs. Transcriptional targets of the miRNAs were computationally predicted and subsequently assessed using transcriptional profiling. Pathway analysis demonstrated that the U-tAs-associated miRNAs are involved in signaling pathways related to known health outcomes of iAs exposure including cancer and diabetes mellitus. Immune response-related mRNAs were also identified with decreased expression levels associated with U-tAs, and predicted to be mediated in part by the arsenic-responsive miRNAs. Results of this study highlight miRNAs as novel responders to prenatal arsenic exposure that may contribute to associated immune response perturbations.
Project description:The Biomarkers of Exposure to ARsenic (BEAR) pregnancy cohort in Gómez Palacio, Mexico was recently established to better understand the impacts of prenatal exposure to inorganic arsenic (iAs). In this study, we examined a subset (n = 40) of newborn cord blood samples for microRNA (miRNA) expression changes associated with in utero arsenic exposure. Levels of iAs in maternal drinking water (DW-iAs) and maternal urine were assessed. Levels of DW-iAs ranged from below detectable values to 236 µg/L (mean = 51.7 µg/L). Total arsenic in maternal urine (U-tAs) was defined as the sum of iAs and its monomethylated and dimethylated metabolites (MMAs and DMAs, respectively) and ranged from 6.2 to 319.7 µg/L (mean = 64.5 µg/L). Genome-wide miRNA expression analysis of cord blood revealed 12 miRNAs with increasing expression associated with U-tAs. Transcriptional targets of the miRNAs were computationally predicted and subsequently assessed using transcriptional profiling. Pathway analysis demonstrated that the U-tAs-associated miRNAs are involved in signaling pathways related to known health outcomes of iAs exposure including cancer and diabetes mellitus. Immune response-related mRNAs were also identified with decreased expression levels associated with U-tAs, and predicted to be mediated in part by the arsenic-responsive miRNAs. Results of this study highlight miRNAs as novel responders to prenatal arsenic exposure that may contribute to associated immune response perturbations.
Anastasia Freedman 
