Biology subjects

Everson, T. M.

Publications and source records attributed to Everson, T. M..

8 recordsLinked to original sources

bioRxiv2026

Tracing PFAS Transfer from Mother to the Fetoplacental Unit: Insights from Trimester-Specific Maternal Serum Profiles

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous endocrine-disrupting pollutants that cross the placenta and affect offspring health, but the extent and timing of their transfer to placental and fetal compartments remain poorly understood. We characterized the relationship between trimester-specific prenatal maternal serum PFAS levels and paired placental and cord plasma levels at term. Data came from the Central Arkansas Glowing prospective cohort (n=151, 2010-2014). Four well-detected PFAS were measured using liquid chromatography-tandem mass spectrometry. Regression, elastic net, and parametric g-formula models tested the association between maternal levels in each trimester and placental or cord PFAS levels. In g-formula models, trimester one (T1) or trimester two (T2) measures consistently had the largest effect sizes associated with placental levels (p<0.001-0.05). Similarly, T1 (PFHxS, PFNA, PFOS, PFOA), T2 (PFNA, PFOS, PFOA), and placental PFOA were associated with cord plasma levels (p<0.05-p<0.001). Results were robust to time-varying adjustment for estimated glomerular filtration rate, serum albumin, or maternal weight. Predictive models improved with additional timepoint measures. Our findings suggest PFOA may transfer more efficiently from the placenta to cord plasma and early-to-mid gestation maternal serum PFAS measures may serve as the most robust sentinels of fetoplacental exposure burden, suggesting early exposure prevention should be prioritized.

pharmacology and toxicology↗

bioRxiv2021

NEOage clocks - Epigenetic clocks to estimate post-menstrual and postnatal age in preterm infants

Epigenetic clocks based on DNA methylation (DNAm) can to accurately predict chronological age and are thought to capture biological aging. A variety of epigenetic clocks have been developed for different tissue types and age ranges, but none has focused on age prediction for preterm infants. Epigenetic estimators of biological age might be especially informative in epidemiologic studies of neonates, particularly those born preterm, since this is a key developmental window. Neonatal DNAm is dynamic and preterm infants are at heightened risk of developmental impairments. We aimed to fill this gap by developing epigenetic clocks for neonatal aging in preterm infants. As part of the Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) study, buccal cells were collected at NICU discharge to profile DNAm levels in 542 very preterm infants. We applied elastic net regression to identify four epigenetic clocks (NEOage) predictive of post-menstrual and postnatal age, compatible with the Illumina EPIC and 450K arrays. We observed high correlations between predicted and reported ages (0.93 - 0.94) with root mean squared errors (1.28 - 1.63 weeks). Epigenetic estimators of neonatal aging in preterm infants can be useful tools to evaluate biological maturity and associations with neonatal and long-term morbidities.

genomics↗

bioRxiv2021

Variation in Placental microRNA Expression Associates with Familial Cardiovascular Disease

In the United States, cardiovascular disease is the leading cause of death, and the rate of maternal mortality remains among the highest of any industrialized nation. Maternal cardiometabolic health throughout gestation and postpartum is representative of placental health and physiology. Both proper placental functionality and placental microRNA expression are essential to successful pregnancy outcomes, and both are highly sensitive to genetic and environmental sources of variation. While placental pathologies, such as preeclampsia, are associated with maternal cardiovascular health and may contribute to the developmental programming of cardiovascular disease, the role of more subtle alterations to placental function and microRNA expression in this relationship remains poorly understood. To develop a more comprehensive understanding of how cardiometabolic health influences placental microRNA expression, and how this shapes placental functionality, we performed small RNA sequencing to investigate microRNA in the placentae from the Rhode Island Child Health Study (n=230). We modeled microRNA counts on maternal family history of cardiovascular disease using negative binomial generalized linear models, and identified microRNAs that were differential expressed (DEmiRs) at a false discovery rate (FDR) less than 0.10. Utilizing parallel mRNA sequencing data and bioinformatic target prediction software, we identified potential mRNA targets of these DEmiRs. We identified 9 DEmiRs, with predicted targets of those miRNA enriched overwhelmingly in the TGF{beta} signaling pathway but also in pathways involving cellular metabolism and immunomodulation. Overall, we identified a robust association existing between familial cardiovascular disease and placental microRNA expression which may be implicated in both placental insufficiencies and the developmental programming of cardiovascular disease.

genetics↗

bioRxiv2020

Placental microRNA Expression Associates with Birthweight through Control of Adipokines: Results from Two Independent Cohorts

MicroRNAs are non-coding RNAs that regulate gene expression post-transcriptionally. In the placenta, the master regulator of fetal growth and development, microRNAs shape the basic processes of trophoblast biology and specific microRNA have been associated with fetal growth. To comprehensively assess the role of microRNAs in placental function and fetal development, we have performed small RNA sequencing to profile placental microRNAs from two independent mother-infant cohorts: the Rhode Island Child Health Study (n=225) and the New Hampshire Birth Cohort Study (n=317). We modeled microRNA counts on infant birthweight percentile (BWP) in each cohort, while accounting for race, sex, parity and technical factors, using negative binomial generalized linear models. We identified microRNAs that were differentially expressed (DEmiRs) with BWP at false discovery rate (FDR) less than 0.05 in both cohorts. hsa-miR-532-5p (miR-532) was positively associated with BWP in both cohorts. By integrating parallel whole transcriptome and small RNA sequencing in the RICHS cohort, we identified putative targets of miR-532. These targets are enriched for pathways involved in adipogenesis, adipocytokine signaling, energy metabolism and hypoxia response, and included Leptin, which we further demonstrated to have decreasing expression with increasing BWP, particularly in male infants. Overall, we have shown a robust and reproducible association of miR-532 with BWP, which could influence BWP through regulation of adipocytokines Leptin and Adiponectin.

genetics↗

bioRxiv2019

Placental DNA methylation signatures of maternal smoking during pregnancy and potential impacts on fetal growth

Maternal smoking during pregnancy (MSDP) contributes to poor birth outcomes, in part through disrupted placental functions, which may be reflected in the placental epigenome. We meta-analyzed the associations between MSDP and placental DNA methylation (DNAm) and between DNAm and birth outcomes within the Pregnancy And Childhood Epigenetics (PACE) consortium (7 studies, N=1700, 344 with any MSDP). We identified 1224 CpGs that were associated with MSDP, of which 341 associated with birth outcomes and 141 associated with gene expression. Only 6 of these CpGs were consistent with the findings from a prior meta-analysis of cord blood DNAm, demonstrating substantial tissue-specific responses to MSDP. The placental MSDP associated CpGs were enriched for growth-factor signaling, hormone activity, inflammation, and vascularization, which play important roles in placental function. We demonstrate links between placental DNAm, MSDP and poor birth outcomes, which may better inform the mechanisms through which MSDP impacts placental function and fetal growth.

genomics↗

bioRxiv2018

Epigenome-wide Analysis Identifies Genes and Pathways Linked to Neurobehavioral Variation in Preterm Infants

Background & ObjectivesNeonatal neurobehavioral performance measures, such as the NICU Network Neurobehavioral Scale (NNNS), have been developed to assess the neurobehavioral characteristics of infants and provide insights into future developmental trajectories. The identification of molecular biomarkers of very early life neurobehavioral experiences could lead to better predictions of the long-term developmental outcomes of high-risk infants including preterm infants. To this end, we aimed to examine whether variability in DNA methylation (DNAm) or epigenetic age from surrogate tissues are associated with NNNS profiles in a cohort of infants born less than 30 weeks postmenstrual age (PMA).\n\nMethodsThis study was performed within the Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) Study and included those infants with complete NNNS assessment data and DNAm measured from buccal cells, collected at near term-equivalent age using the Illumina EPIC array (N=536). We tested whether epigenetic age and age acceleration differed between infants based on their NNNS profile classifications. Then we performed an epigenome-wide association study, to test whether DNAm at individual epigenetic loci varied between these NNNS profile groupings. Models were adjusted for recruitment site, infant sex, postmenstrual age, and estimated tissue heterogeneity.\n\nResultsWe found that infants with an optimal NNNS profile had slightly older epigenetic age than other NOVI infants ({beta}1 = 0.201, p-value = 0.026), and that infants with an atypical NNNS profile had differential methylation at 29 CpG sites (FDR < 10%). The genes annotated to these differentially methylated CpGs included PLA2G4E, TRIM9, GRIK3, and MACROD2, which have previously been associated with neurological structure and function, or with neurobehavioral disorders.\n\nConclusionsGreater epigenetic age is associated with optimal NNNS responses while altered DNAm of multiple genes are associated with an atypical neurobehavioral profile at near-term equivalent age. These findings build upon the existing evidence that epigenetic variations in buccal cells may serve as markers of neonatal neurobehavior and might facilitate early identification of children at risk for abnormal developmental outcome.

epidemiology↗

bioRxiv2018

Epigenome-wide association study of placental DNA methylation and maternal exposure to night shift work in the Rhode Island Child Health Study

ObjectivesCircadian disruption from environmental and occupational exposures can potentially impact health, including offspring health, through epigenetic alterations. Night shift workers experience circadian disruption, but little is known about how this exposure could influence the epigenome of the placenta, which is situated at the maternal-fetal interface. To investigate whether night shift work is associated with variations in DNA methylation patterns of placental tissue, we conducted an epigenome-wide association study (EWAS) of night shift work.\n\nMethodsCpG specific methylation genome-wide of placental tissue (measured with the Illumina 450K array) from participants (n=237) in the Rhode Island Child Health Study (RICHS) who did (n=53) and did not (n=184) report working the night shift was compared using robust linear modeling, adjusting for maternal age, pre-pregnancy smoking, infant sex, maternal adversity, and putative cell mixture.\n\nResultsNight shift work was associated with differential methylation in placental tissue, including CpG sites in the genes NAV1, SMPD1, TAPBP, CLEC16A, DIP2C, FAM172A, and PLEKHG6 (Bonferroni-adjusted p<0.05). CpG sites within NAV1, MXRA8, GABRG1, PRDM16, WNT5A, and FOXG1 exhibited the most hypomethylation, while CpG sites within TDO2, ADAMTSL3, DLX2, and SERPINA1 exhibited the most hypermethylation (BH q<0.10). PER1 was the only core circadian gene demonstrating differential methylation. Functional analysis indicated GO-terms associated with cell-cell adhesion.\n\nConclusionsNight shift work was associated with differential methylation of the placenta, which may have implications for fetal health and development. Additionally, neuron navigator 1 (NAV1) may play a role in the development of the human circadian system.\n\nWhat is already known about this subject?Night shift work and circadian disruption may play a role in the development and progression of many diseases. However, little is known about how circadian disruption impacts human fetal health and development.\n\nWhat are the new findings?Working the night shift is associated with altered placental methylation patterns, and particularly, neuron navigator 1 (NAV1) may play a role in the development of the human circadian system.\n\nHow might this impact on policy or clinical practice in the foreseeable future?Night shift work prior to or during pregnancy may alter the placental epigenome, which has implications for fetal health. Further studies are needed to evaluate night shift work as a possible risk factor for gestational diabetes and to evaluate the impact of circadian disruption on fetal health and development.

epidemiology↗

bioRxiv2017

Cadmium-associated differential methylation throughout the placental genome: epigenome-wide association study of two US birth cohorts

BackgroundCadmium (Cd) is a ubiquitous toxicant that during pregnancy can impair fetal development. Cd sequesters in the placenta where it can impair placental function, impacting fetal development. We aimed to investigate Cd-associated variations in placental DNA methylation (DNAM), associations with gene expression, and identify novel pathways involved in Cd-associated reproductive toxicity.\n\nMethodsUsing placental DNAM and Cd concentrations in the New Hampshire Birth Cohort Study (NHBCS, n=343) and the Rhode Island Child Health Study (RICHS, n=141), we performed an EWAS between Cd and DNAM, adjusting for tissue heterogeneity using a reference-free method. Cohort-specific results were aggregated via inverse variance weighted fixed effects meta-analysis, and variably methylated CpGs were associated with gene expression. We then performed functional enrichment analysis and tests for associations between gene expression and birth metrics.\n\nResultsWe identified 17 Cd-associated differentially methylated CpG sites with meta-analysis p-values < 1e-05, two of which were within a 5% false discovery rate (FDR). Methylation levels at 9 of the 17 loci were associated with increased expression of 6 genes (5% FDR): TNFAIP2, EXOC3L4, GAS7, SREBF1, ACOT7, and RORA. Higher placental expression of TNFAIP2 and ACOT7, and lower expression of RORA, were associated with lower birth weight z-scores (p-values < 0.05).\n\nConclusionCd associated differential DNAM and corresponding DNAM-expression associations at these loci are involved in inflammatory signaling and cell growth. The expression levels of genes involved in inflammatory signaling (TNFAIP2, ACOT7, and RORA), were also associated with birth metrics, suggesting a role for inflammatory processes in Cd-associated reproductive toxicity.\n\nSignificanceCadmium is a toxic environmental pollutant that can impair fetal development. The mechanisms underlying this toxicity are unclear, though disrupted placental functions could play an important role. In this study we examined associations between cadmium concentrations and DNA methylation throughout the placental genome, across two US birth cohorts. We observed cadmium-associated differential methylation, and corresponding methylation-expression associations at genes involved in cellular growth processes and/or immune and inflammatory signaling. This study provides supporting evidence that disrupted placental epigenetic regulation of cellular growth and immune/inflammatory signaling could play a role in cadmium associated reproductive toxicity in human pregnancies.

epidemiology↗