Search

Background: Neonatal opioid withdrawal syndrome (NOWS) is unpredictable. We assessed relationships between placental DNA methylation with in-utero opioid exposure and NOWS severity., Methods: Secondary analysis of a prospective multicenter cohort study of pregnancies on methadone or buprenorphine, ≥34 weeks, singleton, 18 or greater. Placental biopsies were collected. Placental DNA methylation levels of ABCG1, ABCG2, CYP19A1, and HSD11B2 were quantified via pyrosequencing following bisulfite conversion. CYP19A1 mRNA levels and umbilical cord drug levels were determined by RT-qPCR and LC-MS respectively. Severe NOWS was diagnosed through Finnegan scoring. P value < 0.05 was significant., Results: Thirty-eight dyads were included. Promoter region methylation for placental ABCB1 was lower in severe NOWS compared to non-severe NOWS (p = 0.04). Placental CYP19A1 methylation was inversely related to CYP19A1 mRNA levels and associated with umbilical cord norbuprenorphine levels (p < 0.01), but not umbilical cord methadone levels., Discussion: Lower placental ABCB1 methylation was associated with severe NOWS. Higher placental CYP19A1 methylation correlated with higher umbilical cord norbuprenorphine levels., (© 2024. The Author(s).)

Per- and polyfluoroalkyl substances (PFAS) have been detected in the blood of humans and animals worldwide. Exposure to some PFAS are associated with multiple adverse pregnancy outcomes. Existing literature has identified a strong association with PFAS exposure and metabolic dysfunction in humans, including modification of lipid metabolism. Using a subset of the Michigan Mother-Infant Pairs cohort (n = 95), this study investigated associations between first trimester plasma levels of PFAS and maternal lipids and metabolites in the first trimester (T1), at the time of delivery (T3), and in the infant cord blood (CB) using untargeted shotgun lipidomics and metabolomics. Identifying PFAS-induced alterations in the maternal lipid- or metabolome at specific timepoints may help elucidate windows of susceptibility to adverse pregnancy outcomes. Out of 9 PFAS measured, 7 were detected in at least 20% of samples and were used for further analyses. PFOS and PFHxS were measured at the highest concentrations with medians of 5.76 ng/mL and 3.33 ng/mL, respectively. PFOA, PFNA, and PFDA had lower measured values with medians of <1.2 ng/mL. PFHxS concentrations were positively associated with monounsaturated sphingomyelins (SMs) in T1 maternal plasma in adjusted models, determined by an adjusted p-value (q) < 0.1. PFHxS was positively associated with saturated and polyunsaturated SMs and inversely associated with saturated diacylglycerols in T1. Following metabolite-specific analysis, two mono-unsaturated diacylglycerols with carbon chain lengths of 32 and 35 were inversely associated with PFHxS in T1. In T3, only the association between PFHxS and SMs remained, but was attenuated. In addition, PFDA was associated with an increase in polyunsaturated plasmenyl-phosphatidylethanolamines in T3. No associations were identified between PFAS and infant cord blood lipids. Continued research into PFAS associated disruptions in lipid metabolism at sensitive stages of gestation may provide insight into the mechanisms that lead to adverse birth and pregnancy outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Lead (Pb) is a neurotoxicant with early life exposure linked to long-term health effects. Piwi-interacting RNAs (piRNAs) are small non-coding RNAs that associate with PIWIL proteins to induce DNA methylation. It remains unknown whether Pb exposure influences piRNA expression. This study evaluated how perinatal Pb exposure (32 ppm in drinking water) impacts piRNA expression in adult mice and assessed piRNA dysregulation as a potential mechanism for Pb-induced toxicity. Pb exposure effects on piRNA expression and associated gene repression in the germline (testis/ovary) and soma (liver and brain) were evaluated. Small RNA sequencing was used to determine differentially expressed piRNAs, RT-qPCR to examine piRNA target expression, and whole genome bisulfite sequencing to evaluate target DNA methylation status. Three piRNAs (mmpiR-1500602, mmpiR-0201406, and mmpiR-0200026) were significant after multiple testing correction (all downregulated in the male Pb-exposed brain in comparison to control; FDR < 0.05). Within piOxiDB, TAO Kinase 3 was identified as a downstream mRNA target for one of the three Pb-sensitive piRNA. The Pb-exposed male brain exhibited increased Taok3 expression ( p  < 0.05) and decreased DNA methylation (FDR < 0.01). The results demonstrate that perinatal Pb exposure stably influences longitudinal piRNA expression in a tissue- and sex-specific manner, potentially via DNA methylation-directed mechanisms.

Introduction: Epigenetic aging, a marker of biological aging measured by DNA methylation, may be affected by behaviors, including sleep and physical activity. However, investigations of physical activity and sleep with epigenetic aging among pediatric populations are scant and have not accounted for correlated behaviors., Methods: The study population included 472 Mexico City adolescents (52% female). Blood collection and 7-d wrist actigraphy (Actigraph GTX-BT) occurred during a follow-up visit when participants were 14.5 (2.09) yr. Leukocyte DNA methylation was measured with the Infinium MethylationEPIC array after bisulfite conversion, and nine epigenetic clocks were calculated. Sleep versus wake time was identified through a pruned dynamic programing algorithm, and physical activity was processed with Chandler cutoffs. Kmeans clustering was used to select actigraphy-assessed physical activity and sleep behavior clusters. Linear regression analyses were used to evaluate adjusted associations between the clusters and epigenetic aging., Results: There were three unique clusters: "Short sleep/high sedentary behavior," "Adequate sleep duration and late sleep timing/low moderate or vigorous physical activity (MVPA)," and "Adequate sleep duration/high MVPA." Compared with the "Adequate duration/high MVPA," adolescents with "Adequate duration and late sleep timing/low MVPA" had more accelerated aging for the GrimAge clock ( β = 0.63; 95% confidence interval, 0.07-1.19). In pubertal-stratified analyses, more mature adolescents in the "Adequate sleep duration and late sleep timing/low MVPA group" had accelerated epigenetic aging. In contrast, females in the "Short sleep/high sedentary" group had decelerated epigenetic aging for the Wu pediatric clock., Conclusions: Associations between behavior clusters and epigenetic aging varied by pubertal status and sex. Contrary results in the Wu clock suggest the need for future research on pediatric-specific clocks., (Copyright © 2024 by the American College of Sports Medicine.)

Little is understood about the roles of mitochondria in pregnancy-related adaptations. Therefore, we evaluated associations of maternal early-to-mid pregnancy mitochondrial DNA copy number (mtDNAcn) and mtDNA methylation with birth size and gestational length. Michigan women ( n  = 396) provided venous bloodspots at median 11 weeks gestation to quantify mtDNAcn marker NADH-ubiquinone oxidoreductase chain 1 ( ND1 ) using real-time quantitative PCR and mtDNA methylation at several regions within four mitochondria-specific genes using pyrosequencing: MTTF (mitochondrially encoded tRNA phenylalanine), DLOOP (D-loop promoter region, heavy strand), CYTB (cytochrome b), and LDLR (D-loop promoter region, light strand). We abstracted gestational length and birthweight from birth certificates and calculated birthweight z -scores using published references. We used multivariable linear regression to evaluate associations of mtDNAcn and mtDNA methylation with birthweight and birthweight z -scores. Cox Proportional Hazards Models (PHMs) and quantile regression characterized associations of mitochondrial measures with gestational length. We also considered differences by fetal sex. Using linear regression and Cox PHMs, mtDNAcn was not associated with birth outcomes, whereas associations of mtDNA methylation with birth outcomes were inconsistent. However, using quantile regression, mtDNAcn was associated with shorter gestation in female newborns at the upper quantiles of gestational length, but with longer gestational length in males at the lower quantiles of gestational length. Maternal LDLR, DLOOP , and MTTF methylation was associated with longer gestational length in females at the upper quantiles and in males at lower gestational length quantiles. Maternal mtDNAcn and mtDNA methylation were associated with gestational length in babies born comparatively early or late, which could reflect adaptations in mitochondrial processes that regulate the length of gestation., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press.)

DNA methylation (DNAm) is a chemical modification of DNA that can be influenced by various factors, including age, environment, and lifestyle. An epigenetic clock is a predictive tool that measures biological age based on DNAm levels. It can provide insights into an individual's biological age, which may differ from their chronological age. This difference, known as the epigenetic age acceleration, may indicate the state of one's health and risk for age-related diseases. Moreover, epigenetic clocks are used in studies of aging to assess the effectiveness of anti-aging interventions and to understand the underlying mechanisms of aging and disease. Various epigenetic clocks have been developed using samples from different populations, tissues, and cell types, typically by training high-dimensional linear regression models with an elastic net penalty. While these models can predict mean biological age with high precision, there is a lack of uncertainty quantification which is important for interpreting the precision of age estimations and for clinical decision-making. To understand the distribution of a biological age clock beyond its mean, we propose a general pipeline for training epigenetic clocks, based on an integration of high-dimensional quantile regression and conformal prediction, to effectively reveal population heterogeneity and construct prediction intervals. Our approach produces adaptive prediction intervals not only achieving nominal coverage but also accounting for the inherent variability across individuals. By using the data collected from 728 blood samples in 11 DNAm datasets from children, we find that our quantile regression-based prediction intervals are narrower than those derived from conventional mean regression-based epigenetic clocks. This observation demonstrates an improved statistical efficiency over the existing pipeline for training epigenetic clocks. In addition, the resulting intervals have a synchronized varying pattern to age acceleration, effectively revealing cellular evolutionary heterogeneity in age patterns in different developmental stages during individual childhoods and adolescent cohort. Our findings suggest that conformalized high-dimensional quantile regression can produce valid prediction intervals and uncover underlying population heterogeneity. Although our methodology focuses on the distribution of aging in children, it is applicable to a broader range of populations to improve understanding of epigenetic age beyond the mean. This inference-based toolbox could provide valuable insights for future applications of epigenetic interventions for age-related diseases.

Introduction: Early childhood development is a strong predictor of long-term health outcomes, potentially mediated via epigenetics (DNA methylation). The aim of the current study was to examine how childhood experiences, punitive parenting, and an intergenerational psychotherapeutic intervention may impact DNA methylation in young children and their mothers., Methods: Mothers and their infants/toddlers between 0 and 24 months were recruited at baseline (n = 146, 73 pairs) to participate in a randomized control trial evaluating the effectiveness of The Michigan Model of Infant Mental Health Home Visiting (IMH-HV) parent-infant psychotherapy compared to treatment as usual. Baseline and 12-month post-enrollment data were collected in the family's home and included self-report questionnaires, biological saliva samples, home environment observation, video-taped parent-child interaction, and audio-recorded interviews. Saliva DNA methylation was measured at the genes, nuclear receptor subfamily 3 group C member 1 (NR3C1), solute carrier family 6 member 4 (SLC6A4), brain-derived neurotrophic factor (BDNF), and the genetic element, long interspersed nuclear element-1 (LINE1)., Results: For mothers, baseline methylation of BDNF, SLC6A4, NR3C1, or LINE1 was largely not associated with baseline measures of their childhood adversity, adverse life experiences, demographic characteristics related to structurally driven inequities, or to IMH-HV treatment effect. In infants, there were suggestions that methylation in SLC6A4 and LINE1 was associated with parenting attitudes. Infant BDNF methylation suggested an overall decrease in response to IMH-HV psychotherapy over 12 months., Conclusions: Overall, our findings suggest that the epigenome in infants and young children may be sensitive to both early life experiences and parent-infant psychotherapy., (© 2024 The Author(s). Brain and Behavior published by Wiley Periodicals LLC.)

Objective: The aim of the study is to examine associations between years of firefighting service and eight chronological age-adjusted measures of blood leukocyte epigenetic age acceleration: Horvath, Hannum, SkinBloodClock, Intrinsic, Extrinsic, PhenoAge, GrimAge, and DNAm telomere length., Methods: The study used a repeated measures analysis of data from 379 incumbent firefighters from eight career departments and 100 recruit firefighters from two of the departments, across the United States., Results: Incumbent firefighters had on average greater epigenetic age acceleration compared with recruit firefighters, potentially due to the cumulative effect of occupational exposures. However, among incumbent firefighters, additional years of service were associated with epigenetic age deceleration, particularly for GrimAge, a strong predictor of mortality., Conclusions: Long-term studies with more specific occupational exposure classification are needed to better understand the relationship between years of service and aging biomarkers., Competing Interests: Conflicts of Interest: None declared., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Occupational and Environmental Medicine.)

Although toxicology uses animal models to represent real-world human health scenarios, a critical translational gap between laboratory-based studies and epidemiology remains. In this study, we aimed to understand the toxicoepigenetic effects on DNA methylation after developmental exposure to two common toxicants, the phthalate di(2-ethylhexyl) phthalate (DEHP) and the metal lead (Pb), using a translational paradigm that selected candidate genes from a mouse study and assessed them in four human birth cohorts. Data from mouse offspring developmentally exposed to DEHP, Pb, or control were used to identify genes with sex-specific sites with differential DNA methylation at postnatal day 21. Associations of human infant DNA methylation in homologous mouse genes with prenatal DEHP or Pb were examined with a meta-analysis. Differential methylation was observed on 6 cytosines (adjusted-p < 0.05) and 90 regions (adjusted-p < 0.001). This translational approach offers a unique method that can detect conserved epigenetic differences that are developmentally susceptible to environmental toxicants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Firefighters are occupationally exposed to per- and polyfluoroalkyl substances (PFAS). This study objective was to compare serum PFAS concentrations in incumbent and recruit firefighters and evaluate temporal trends among recruits., Methods: Serum PFAS concentrations were measured in 99 incumbent and 55 recruit firefighters at enrollment in 2015-2016, with follow-up 20 to 37 months later for recruits. Linear and logistic regression and linear mixed-effects models were used for analyses. Fireground exposure impact on PFAS concentrations was investigated using adjusted linear and logistic regression models., Results: Incumbents had lower n-PFOA and PFNA than recruits and most PFAS significantly decreased over time among male recruits. No significant links were found between cumulative fireground exposures and PFAS concentrations., Conclusions: Serum PFAS concentrations were not increased in incumbent firefighters compared with recruits and were not associated with cumulative fireground exposures., Competing Interests: Conflict of interest: J.M.F. received funding from the CDC, the Emergency Medicine Foundation, the United States Department of Defense, NIH, and Merck and Company. M.A.F. received funding from Gray Ritter and Graham for background consulting for health effects of pesticides, not related to the topic of the current study. J.M.Go. received funding from the National Institute of Diabetes and Digestive and Kidney Disorders. J.M.Gr. received FEMA funding on two firefighter projects to which she subcontracts with the University of Arizona (Dr Burgess) to conduct sample and data management., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American College of Occupational and Environmental Medicine.)

Few studies have related early life lead exposure to adolescent biological aging, a period characterized by marked increases in maturational tempo. We examined associations between prenatal and childhood lead exposure and adolescent biological age (mean 14.5 years) utilizing multiple epigenetic clocks including: intrinsic (IEAA), extrinsic (EEAA), Horvath, Hannum, PhenoAge, GrimAge, Skin-Blood, Wu, PedBE, as well as DNA methylation derived telomere length (DNAmTL). Epigenetic clocks and DNAmTL were calculated via adolescent blood DNA methylation measured by Infinium MethylationEPIC BeadChips. We constructed general linear models (GLMs) with individual lead measures predicting biological age. We additionally examined sex-stratified models and lead by sex interactions, adjusting for adolescent age and lead levels, maternal smoking and education, and proportion of cell types. We also estimated effects of lead exposure on biological age using generalized estimating equations (GEE). First trimester blood lead was positively associated with a 0.14 increase in EEAA age in the GLMs though not the GEE models (95%CI 0.03, 0.25). First and 2nd trimester blood lead levels were associated with a 0.02 year increase in PedBE age in GLM and GEE models (1st trimester, 95%CI 0.004, 0.03; 2nd trimester, 95%CI 0.01, 0.03). Third trimester and 24 month blood lead levels were associated with a -0.06 and -0.05 decrease in Skin-Blood age, respectively, in GLM models. Additionally, 3rd trimester blood lead levels were associated with a 0.08 year decrease in Hannum age in GLM and GEE models (95%CI -0.15, -0.01). There were multiple significant results in sex-stratified models and significant lead by sex interactions, where males experienced accelerated biological age, compared to females who saw a decelerated biological age, with respect to IEAA, EEAA, Horvath, Hannum, and PedBE clocks. Further research is needed to understand sex-specific relationships between lead exposure and measures of biological aging in adolescence and the trajectory of biological aging into young adulthood., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

DNA methylation, an epigenetic mark, has become a common outcome in epidemiological studies with the aid of affordable and reliable technologies. Yet the most widespread technique used to assess methylation, bisulfite conversion, does not allow for the differentiation of regular DNA methylation (5-mC) and other cytosine modifications, like that of hydroxymethylation (5-hmC). As both 5-mC and 5-hmC have distinct biological roles, sometimes with opposing effects, it is crucial to understand the difference between these marks. To characterize 5-mC and 5-hmC in cord blood and expand on previously published results in smaller cohorts, 73 samples from infants in the Michigan Mother Infant Pairs cohort were paired bisulfite and oxidative bisulfite converted. 5-mC and 5-hmC were assessed on the Illumina Infinium EPIC array, using maximum likelihood methods, and sex-specific differences of these marks were analyzed. 5-mC and 5-hmC were both broadly distributed across the genome, and 5-hmC was prevalent, with proportions of 0.01-0.55. Sex-specific analysis revealed total methylation was different on 17,000 sites (q<0.05), but only different at 1,866 and 5 sites of 5-mC and 5-hmC specifically. These results add additional support to the literature and demonstrate the importance of differentiating between 5-mC and 5-hmC in epidemiological studies going forward., Competing Interests: Declaration of Interest The authors declare no conflicts of interest.

Prostate cancer is the leading incident cancer among men in the United States. Firefighters are diagnosed with this disease at a rate 1.21 times higher than the average population. This increased risk may result from occupational exposures to many toxicants, including per- and polyfluoroalkyl substances (PFAS). This study assessed the association between firefighting as an occupation in general or PFAS serum levels, with DNA methylation. Only genomic regions previously linked to prostate cancer risk were selected for analysis: GSTP1, Alu repetitive elements, and the 8q24 chromosomal region. There were 444 male firefighters included in this study, with some analyses being conducted on fewer participants due to missingness. Statistical models were used to test associations between exposures and DNA methylation at CpG sites in the selected genomic regions. Exposure variables included proxies of cumulative firefighting exposures (incumbent versus academy status and years of firefighting experience) and biomarkers of PFAS exposures (serum concentrations of 9 PFAS). Proxies of cumulative exposures were associated with DNA methylation at 15 CpG sites and one region located within FAM83A (q-value <0.1). SbPFOA was associated with 19 CpG sites (q < 0.1), but due to low detection rates, this PFAS was modeled as detected versus not detected in serum. Overall, there is evidence that firefighting experience is associated with differential DNA methylation in prostate cancer risk loci, but this study did not find evidence that these differences are due to PFAS exposures specifically., (© 2024 The Authors. Environmental and Molecular Mutagenesis published by Wiley Periodicals LLC on behalf of Environmental Mutagenesis and Genomics Society.)

Background: Environmental factors can influence epigenetic regulation, including DNA methylation, potentially contributing to systemic lupus erythematosus (SLE) development and progression. We compared methylation of the B cell costimulatory CD70 gene, in persons with lupus and controls, and characterized associations with age., Results: In 297 adults with SLE and 92 controls from the Michigan Lupus Epidemiology and Surveillance (MILES) Cohort, average CD70 methylation of CD4 + T cell DNA across 10 CpG sites based on pyrosequencing of the promoter region was higher for persons with SLE compared to controls, accounting for covariates [β = 2.3, p = 0.011]. Using Infinium MethylationEPIC array data at 18 CD70-annoted loci (CD4 + and CD8 + T cell DNA), sites within the promoter region tended to be hypomethylated in SLE, while those within the gene region were hypermethylated. In SLE but not controls, age was significantly associated with pyrosequencing-based CD70 methylation: for every year increase in age, methylation increased by 0.14 percentage points in SLE, accounting for covariates. Also within SLE, CD70 methylation approached a significantly higher level in Black persons compared to White persons (β = 1.8, p = 0.051)., Conclusions: We describe altered CD70 methylation patterns in T lymphocyte subsets in adults with SLE relative to controls, and report associations particular to SLE between methylation of this immune-relevant gene and both age and race, possibly a consequence of "weathering" or accelerated aging which may have implications for SLE pathogenesis and potential intervention strategies., (Copyright © 2023. Published by Elsevier Ltd.)

Biological clock technologies are designed to assess the acceleration of biological age (B-age) in diverse cell types, offering a distinctive opportunity in toxicogenomic research to explore the impact of environmental stressors, social challenges, and unhealthy lifestyles on health impairment. These clocks also play a role in identifying factors that can hinder aging and promote a healthy lifestyle. Over the past decade, researchers in epigenetics have developed testing methods that predict the chronological and biological age of organisms. These methods rely on assessing DNA methylation (DNAm) levels at specific CpG sites, RNA levels, and various biomolecules across multiple cell types, tissues, and entire organisms. Commonly known as 'biological clocks' (B-clocks), these estimators hold promise for gaining deeper insights into the pathways contributing to the development of age-related disorders. They also provide a foundation for devising biomedical or social interventions to prevent, reverse, or mitigate these disorders. This review article provides a concise overview of various epigenetic clocks and explores their susceptibility to environmental stressors.

The global decline of terrestrial species is largely due to the degradation, loss and fragmentation of their habitats. The conversion of natural ecosystems for cropland, rangeland, forest products and human infrastructure are the primary causes of habitat deterioration. Due to the paucity of data on the past distribution of species and the scarcity of fine-scale habitat conversion maps, however, accurate assessment of the recent effects of habitat degradation, loss and fragmentation on the range of mammals has been near impossible. We aim to assess the proportions of available habitat within the lost and retained parts of mammals' distribution ranges, and to identify the drivers of habitat availability. We produced distribution maps for 475 terrestrial mammals for the range they occupied 50 years ago and compared them to current range maps. We then calculated the differences in the percentage of 'area of habitat' (habitat available to a species within its range) between the lost and retained range areas. Finally, we ran generalized linear mixed models to identify which variables were more influential in determining habitat availability in the lost and retained parts of the distribution ranges. We found that 59% of species had a lower proportion of available habitat in the lost range compared to the retained range, thus hypothesizing that habitat loss could have contributed to range declines. The most important factors negatively affecting habitat availability were the conversion of land to rangeland and high density of livestock. Significant intrinsic traits were those related to reproductive timing and output, habitat breadth and medium body size. Our findings emphasize the importance of implementing conservation strategies to mitigate the impacts caused by human activities on the habitats of mammals, and offer evidence indicating which species have the potential to reoccupy portions of their former range if other threats cease to occur., (© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)

Endocrine disrupting chemicals (EDCs) are a diverse group of toxicants detected in populations globally. Prenatal EDC exposures impact birth and childhood outcomes. EDCs work through persistent changes at the molecular, cellular, and organ level. Molecular and biochemical signals or 'omics' can be measured at various functional levels - including the epigenome, transcriptome, proteome, metabolome, and the microbiome. In this narrative review, we introduce each omics and give examples of associations with prenatal EDC exposures. There is substantial research on epigenomic modifications in offspring exposed to EDCs during gestation, and a growing number of studies evaluating the transcriptome, proteome, metabolome, or microbiome in response to these exposures. Multi-omics, integrating data across omics layers, may improve understanding of disrupted function pathways related to early life exposures. We highlight several data integration methods to consider in multi-omics studies. Information from multi-omics can improve understanding of the biological processes and mechanisms underlying prenatal EDC toxicity., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Epigenetic changes may be biomarkers of health. Epigenetic age acceleration (EAA), the discrepancy between epigenetic age measured via epigenetic clocks and chronological age, is associated with morbidity and mortality. However, the intersection of epigenetic clocks with microRNAs (miRNAs) and corresponding miRNA-based health implications have not been evaluated. We analyzed DNA methylation and miRNA profiles from blood sampled among 332 individuals enrolled across 2 U.S.-based firefighter occupational studies (2015-2018 and 2018-2020). We considered 7 measures of EAA in leukocytes (PhenoAge, GrimAge, Horvath, skin-blood, and Hannum epigenetic clocks, and extrinsic and intrinsic epigenetic age acceleration). We identified miRNAs associated with EAA using individual linear regression models, adjusted for sex, race/ethnicity, chronological age, and cell type estimates, and investigated downstream effects of associated miRNAs with miRNA enrichment analyses and genomic annotations. On average, participants were 38 years old, 88% male, and 75% non-Hispanic white. We identified 183 of 798 miRNAs associated with EAA (FDR q  < 0.05); 126 with PhenoAge, 59 with GrimAge, 1 with Horvath, and 1 with the skin-blood clock. Among miRNAs associated with Horvath and GrimAge, there were 61 significantly enriched disease annotations including age-related metabolic and cardiovascular conditions and several cancers. Enriched pathways included those related to proteins and protein modification. We identified miRNAs associated with EAA of multiple epigenetic clocks. PhenoAge had more associations with individual miRNAs, but GrimAge and Horvath had greater implications for miRNA-associated pathways. Understanding the relationship between these epigenetic markers could contribute to our understanding of the molecular underpinnings of aging and aging-related diseases., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Objective: Per- and polyfluoro-alkyl substances (PFAS) and lead (Pb) are ubiquitous environmental toxicants with apparent impact on cardiovascular disease (CVD) risk. As one possible mechanism for this increased risk, we have previously demonstrated an association between Pb exposure and heightened cardiovascular reactivity to acute psychological stress, a CVD risk factor. The present study expands this approach and considers both PFAS and Pb exposures (and the possible interaction)., Methods: We assessed 14 serum PFAS and whole blood Pb concentrations in a sample of 9-11 year-old children (N = 291; 43.2% White, 56.8% Black; 53.5% female). We measured cardiovascular functioning at rest and during psychological stress as well as multiple indicators of subclinical CVD including resting blood pressure (BP), carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), and left ventricular mass (LVM). Data analysis included general linear modeling as well as a non-parametric approach to study metal mixtures, specifically Bayesian Kernel Machine Regression (BKMR)., Results: Significant interactions between different PFAS and with Pb suggest the importance of considering toxicant mixtures when assessing potential disruption of the cardiovascular system. The pattern of findings suggests that greater "vascular reactivity" (elevated BP and vascular resistance during acute psychological stress) was associated with higher concentrations of perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and Pb, but only when perfluorooctanoic acid (PFOA) was concurrently elevated. With respect to subclinical outcomes, increasing perfluorodecanoic acid (PFDA) was associated with greater cIMT (β = 0.21, p = 0.010)., Conclusion: To our knowledge this is the first study to consider how PFAS exposures might affect cardiovascular functioning and subclinical disease. Although a complex pattern of associations emerged, it does appear that PFAS and Pb can be classified as "cardiovascular disruptors" in children. Further research is needed to replicate these novel findings and determine whether these disruptions produce future cardiovascular disease., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interestsBrooks B. Gump reports financial support was provided by National Institute of Health. Patrick Parsons, Kannan Karunthachalam reports financial support was provided by National Institute of Health., (Copyright © 2023. Published by Elsevier Inc.)

Background: Epidemiological studies on children and adults have linked toxicants from plastics and personal care products to metabolic disruption. Yet, the impact of endocrine-disrupting chemicals (EDCs) on adolescent metabolic syndrome (MetS) risk during early and mid-adolescence is unclear., Methods: To examine the links between exposure to EDCs and MetS risk and its components, cross-sectional data from 344 Mexican youth in early-to-mid adolescence (10-17 years) were analyzed. Urinary biomarker concentrations of phthalates, phenol, and paraben analytes were measured from a single spot urine sample collected in 2015; study personnel obtained anthropometric and metabolic measures. We examined associations between summary phthalates and metabolites, phenol, and paraben analytes with MetS risk z-scores using linear regression, adjusted for specific gravity, sex, age, pubertal status, smoking, alcohol intake, physical activity level, and screen time. As a secondary aim, mediation analysis was conducted to evaluate the role of hormones in the association between summary phthalates with lipids and MetS risk z-scores., Results: The mean (SD) age was 13.2 (1.9) years, and 50.9% were female. Sex-stratified analyses revealed associations between summary phthalates and lipids ratio z-scores, including Σ DEHP [β = 0.21 (95% CI: 0.04, 0.37; p < 0.01)], phthalates from plastic sources (Σ Plastic) [β = 0.22 (95% CI: 0.05, 0.39; p < 0.01)], anti-androgenic phthalates (Σ AA) [β = 0.22 (95% CI: 0.05, 0.39; p < 0.01)], and individual phthalate metabolites (MEHHP, MEOHP, and MECPP) among males. Among females, BPA [β = 0.24 (95% CI: 0.03, 0.44; p < 0.05)] was positively associated with lipids ratio z-score and one phenol (2,5 DCP) [β = 0.09 (95% CI: 0.01, 0.18); p < 0.05)] was associated with increased waist circumference z-score. Results showed no evidence of mediation by hormone concentrations in the association between summary phthalates with lipids ratio or MetS risk z-scores., Conclusion: Higher EDC exposure was positively associated with serum lipids during adolescence, particularly among males., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The biological pathways which link lead (Pb) and long-term outcomes are unclear, though rodent models and a few human studies suggest Pb may alter the body's stress response systems, which over time, can elicit dysregulated stress responses with cumulative impacts. This study examined associations between prenatal and early childhood Pb exposure and adolescent allostatic load, an index of an individual's body burden of stress in multiple biological systems, and further examined sex-based associations. Among 391 (51% male) participants in the ELEMENT birth cohort, we related trimester-specific maternal blood Pb, 1-month postpartum maternal tibia and patella Pb, and child blood Pb at 12-24 months to an allostatic load index in adolescence comprised of biomarkers of cardiovascular, metabolic, neuroendocrine, and immune function. The results were overall mixed, with prenatal exposure, particularly maternal bone Pb, being positively associated with allostatic load, and early childhood Pb showing mixed results for males and females. In adjusted Poisson regression models, 1 mcg/g increase in tibia Pb was associated with a 1% change in expected allostatic load (IRR = 1.01; 95%CI 0.99, 1.02). We found a significant Pb × sex interaction (IRR = 1.05; 95%CI 1.01, 1.10); where males saw an increasing percent change in allostatic load as 12 month Pb levels increased compared to females who saw a decreasing allostatic load. Further examination of allostatic load will facilitate the determination of potential mechanistic pathways between developmental toxicant exposures and later-in-life cardiometabolic outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Aims: To identify associations between DNA methylation (DNAm) across the epigenome and symptoms related to attention-deficit/hyperactivity disorder in a population of Hispanic children. Materials & methods: Among 517 participants in the ELEMENT study aged 9-18 years, we conducted an epigenome-wide association study examining associations between blood leukocyte DNAm and performance on the Conners' continuous performance test (CPT3). Results: DNAm at loci in or near ZNF814 , ELF4 and OR6K6 and functional enrichment for gene pathways pertaining to ferroptosis, inflammation, immune response and neurotransmission were significantly related to CPT3 scores. Conclusion: DNAm was associated with CPT3 performance. Further analysis is warranted to understand how these genes and enriched pathways contribute to attention-deficit/hyperactivity disorder.

Purpose: This study explored approaches for measuring vocabulary among bilingual children with varying levels of proficiency in Spanish and English., Method: One hundred fifteen kindergarten and first-grade Spanish-English-speaking children completed measures of vocabulary and sentence repetition in Spanish and English. Scores were derived from their responses to the vocabulary measure: Spanish-only vocabulary, English-only vocabulary, conceptual vocabulary, and total vocabulary. Best language sentence repetition was also obtained. Using both visualization of data and statistical analysis, we tested for potential associations between children's relative language skills in Spanish and English and the scores they received on each of the vocabulary metrics., Results: Participants' single-language vocabulary scores were linearly associated with their relative language scores. Higher relative Spanish language skills corresponded with higher Spanish-only vocabulary scores, and higher English language skills corresponded with higher English-only vocabulary scores. A quadratic association between children's relative language and their conceptual vocabulary scores was observed. Children with more balanced skills in Spanish and English received lower scores for conceptual vocabulary. No association between total vocabulary and relative language was observed., Conclusions: Results revealed evidence of differential test bias for single-language vocabulary scores and conceptual vocabulary scores. Spanish-only vocabulary underestimated knowledge of participants with higher English proficiency, whereas English-only vocabulary underestimated knowledge of participants with higher Spanish proficiency. Conceptual scoring yielded lower values for participants with relatively balanced proficiency in Spanish and English. There is need for further consideration of score and test functioning across the full continuum of bilinguals with dynamic proficiencies in each of their languages., Supplemental Material: https://doi.org/10.23641/asha.23796330.

Background: Epigenetic clocks are promising tools for assessing biological age. We assessed the accuracy of pediatric epigenetic clocks in gestational and chronological age determination., Results: Our study used data from seven tissue types on three DNA methylation profiling microarrays and found that the Knight and Bohlin clocks performed similarly for blood cells, while the Lee clock was superior for placental samples. The pediatric-buccal-epigenetic clock performed the best for pediatric buccal samples, while the Horvath clock is recommended for children's blood cell samples. The NeoAge clock stands out for its unique ability to predict post-menstrual age with high correlation with the observed age in infant buccal cell samples., Conclusions: Our findings provide valuable guidance for future research and development of epigenetic clocks in pediatric samples, enabling more accurate assessments of biological age., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Maternal sleep and circadian health during pregnancy are emerging as important predictors of pregnancy outcomes, but examination of potential epigenetic mechanisms is rare. We investigated links between maternal leukocyte DNA methylation of circadian genes and birth outcomes within a pregnancy cohort. Women ( n  = 96) completed a questionnaire and provided a blood sample at least once during early-to-mid pregnancy (average gestation weeks = 14.2). Leukocyte DNA was isolated and DNA methylation (average percent of methylation) at multiple CpG sites within BMAL1 , PER1 , and MTNR1B genes were quantified by pyrosequencing. Birth outcomes including gestational age at delivery, birthweight, and head circumference were abstracted from medical charts. Linear regression analyses were run between each CpG site with birth outcomes, adjusting for important confounders. Sleep duration and timing were assessed as secondary exposures. Higher methylation of a CpG site in PER1 was associated with smaller log-transformed head circumference (β=-0.02 with 95% CI -0.02 to 0.01; P, trend = 0.04). Higher methylation of MTNR1B (averaged across sites) was associated with lower log-transformed birthweight (-0.08 with 95% CI -0.16 to -0.01; P, trend = 0.0495). In addition, longer sleep duration was associated with higher birthweight (0.10 with 95% CI 0.02 to 0.18 comparing > 9 h to < 8 h; P, trend = 0.04). This pilot investigation revealed that higher methylation of PER1 and MTNR1B genes, and sleep duration measured in early-to-mid pregnancy were related to birth outcomes.

Introduction: The developing epigenome changes rapidly, potentially making it more sensitive to toxicant exposures. DNA modifications, including methylation and hydroxymethylation, are important parts of the epigenome that may be affected by environmental exposures. However, most studies do not differentiate between these two DNA modifications, possibly masking significant effects. Methods: To investigate the relationship between DNA hydroxymethylation and developmental exposure to common contaminants, a collaborative, NIEHS-sponsored consortium, TaRGET II, initiated longitudinal mouse studies of developmental exposure to human-relevant levels of the phthalate plasticizer di(2-ethylhexyl) phthalate (DEHP), and the metal lead (Pb). Exposures to 25 mg DEHP/kg of food (approximately 5 mg DEHP/kg body weight) or 32 ppm Pb-acetate in drinking water were administered to nulliparous adult female mice. Exposure began 2 weeks before breeding and continued throughout pregnancy and lactation, until offspring were 21 days old. At 5 months, perinatally exposed offspring blood and cortex tissue were collected, for a total of 25 male mice and 17 female mice ( n = 5-7 per tissue and exposure). DNA was extracted and hydroxymethylation was measured using hydroxymethylated DNA immunoprecipitation sequencing (hMeDIP-seq). Differential peak and pathway analysis was conducted comparing across exposure groups, tissue types, and animal sex, using an FDR cutoff of 0.15. Results: DEHP-exposed females had two genomic regions with lower hydroxymethylation in blood and no differences in cortex hydroxymethylation. For DEHP-exposed males, ten regions in blood (six higher and four lower) and 246 regions (242 higher and four lower) and four pathways in cortex were identified. Pb-exposed females had no statistically significant differences in blood or cortex hydroxymethylation compared to controls. Pb-exposed males, however, had 385 regions (all higher) and six pathways altered in cortex, but no differential hydroxymethylation was identified in blood. Discussion: Overall, perinatal exposure to human-relevant levels of two common toxicants showed differences in adult DNA hydroxymethylation that was specific to sex, exposure type, and tissue, but male cortex was most susceptible to hydroxymethylation differences by exposure. Future assessments should focus on understanding if these findings indicate potential biomarkers of exposure or are related to functional long-term health effects., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Petroff, Cavalcante, Colacino, Goodrich, Jones, Lalancette, Morgan, Neier, Perera, Rygiel, Svoboda, Wang, Sartor and Dolinoy.)

Endocrine-disrupting chemicals (EDCs) may impact sleep during the menopausal transition by altering sex hormones. However, these studies are scarce among Latin American women. This investigation utilized cross-sectional and retrospective data from midlife women enrolled in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) study to examine associations between exposure to EDCs (phthalates, phenols, and parabens) and sleep health measures. For cross-sectional analyses, single spot urine samples were collected between 2017-2019 from a pilot sample of women (N = 91) of midlife age to estimate the urinary concentration of individual phthalates, phenols, and parabens and to calculate the summary concentration of phthalate mixtures. Seven-day nightly sleep duration, midpoint, and fragmentation were obtained from wrist-actigraphy devices and estimated from the actigraphy data using a pruned dynamic programming algorithm. Self-reported poor sleep quality was assessed by one item from the Pittsburgh Sleep Quality Index (PSQI). We examined associations between urinary summary phthalate mixtures, phthalate metabolites, phenol, and paraben analytes with each sleep measure using linear or logistic (to compute odds of poor sleep quality only) regression models adjusted for specific gravity, age, and socioeconomic status. We ran similar regression models for retrospective analyses (N = 74), except that urine exposure biomarker data were collected in 2008 when women were 24-50 years old. At the 2017-2019 midlife visit, 38% reported poor sleep quality. Cross-sectionally, EDCs were associated with longer sleep duration, earlier sleep timing, and more fragmented sleep. For example, every 1-unit IQR increase in the phenol triclosan was associated with a 26.3 min per night (95% CI: 10.5, 42.2; P < 0.05) longer sleep duration and marginally associated with 0.2 decimal hours (95% CI: -0.4, 0.0; P < 0.10) earlier sleep midpoint; while every 1-unit IQR increase in the phthalate metabolite MEHP was associated with 1.1% higher sleep fragmentation (95% CI: 0.1, 2.1; P < 0.05). Retrospective study results generally mirrored cross-sectional results such that EDCs were linked to longer sleep duration, earlier sleep timing, and more fragmented sleep. EDCs were not significantly associated with odds of self-reported poor sleep quality. Results from cross-sectional and retrospective analyses revealed that higher exposure to EDCs was predictive of longer sleep duration, earlier sleep timing, and more fragmented sleep among midlife women., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Epigenetic modifications such as DNA methylation may influence gene expression and phenotypes, including obesity in childhood. The directionality of this relationship is nevertheless unclear, and some evidence suggests that adiposity modifies the epigenome, rather than the other way around. In this pilot study, we utilize data from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) study to examine whether measures of adiposity in childhood and early adolescence are associated with repeated measures of blood leukocyte DNA methylation at LINE-1 repetitive elements and two genes implicated in growth and adiposity: H19 and HSD11B2. Longitudinal epigenetic data were generated from cord blood and blood from follow-up visits in early and late adolescence. We assessed interactions between age and measures of body mass index (BMI) at 5 years of age and weight, BMI and waist circumference in early adolescence to infer whether adiposity deflects age-related DNA methylation changes throughout childhood. Applying linear mixed-effects models, we found an inverse association between measures of childhood BMI (kg/m 2 ) and early-teen weight (kg) with repeat measures of H19 DNA methylation. We did not observe any statistically significant associations (p-value <.05) between any anthropometric measures and DNA methylation at LINE-1 or HSD11B2. We did not demonstrate statistically significant evidence in support of deflection of age-related DNA methylation trajectories by adiposity-related measures (age by adiposity interaction term). Given the pilot nature of this study, the relationships between repeat measures of DNA methylation and adiposity-measures across childhood merit further exploration in larger study populations., (© 2022 The Authors. Clinical Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

Background: Per- and polyfluoroalkyl substances (PFAS) are chemicals that are resistant to degradation and ubiquitous in our environments. PFAS may impact the developing epigenome, but current human evidence is limited to assessments of total DNA methylation. We assessed associations between first trimester PFAS exposures with newborn DNA methylation, including 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC). DNA methylation mediation of associations between PFAS and birth outcomes were explored in the Michigan Mother Infant Pairs cohort. Nine PFAS were measured in maternal first trimester blood. Seven were highly detected and included for analysis: PFHxS, PFOA, PFOS, PFNA, PFDA, PFUnDA, and MeFOSAA. Bisulfite-converted cord blood DNA (n = 141) and oxidative-bisulfite-converted cord blood (n = 70) were assayed on Illumina MethylationEPIC BeadChips to measure total DNA methylation (5-mC + 5-hmC) and 5-mC/5-hmC. Correcting for multiple comparisons, beta regressions were used to assess associations between levels of PFAS and total methylation, 5-mC, or 5-hmC. Nonlinear mediation analyses were used to assess the epigenetic meditation effect between PFAS and birth outcomes., Results: PFAS was significantly associated with total methylation (q < 0.05: PFHxS-12 sites; PFOS-19 sites; PFOA-2 sites; PFNA-3 sites; PFDA-4 sites). In 72 female infants and 69 male infants, there were sex-specific associations between five PFAS and DNA methylation. 5-mC and 5-hmC were each significantly associated with thousands of sites for PFHxS, PFOS, PFNA, PFDA, PFUnDA, and MeFOSAA (q < 0.05). Clusters of 5-mC and 5-hmC sites were significant mediators between PFNA and PFUnDA and decreased gestational age (q < 0.05)., Conclusions: This study demonstrates the mediation role of specific types of DNA methylation on the relationship between PFAS exposure and birth outcomes. These results suggest that 5-mC and 5-hmC may be more sensitive to the developmental impacts of PFAS than total DNA methylation., (© 2023. The Author(s).)

The placenta mediates adverse pregnancy outcomes, including preeclampsia, which is characterized by gestational hypertension and proteinuria. Placental cell type heterogeneity in preeclampsia is not well-understood and limits mechanistic interpretation of bulk gene expression measures. We generated single-cell RNA-sequencing samples for integration with existing data to create the largest deconvolution reference of 19 fetal and 8 maternal cell types from placental villous tissue (n = 9 biological replicates) at term (n = 40,494 cells). We deconvoluted eight published microarray case-control studies of preeclampsia (n = 173 controls, 157 cases). Preeclampsia was associated with excess extravillous trophoblasts and fewer mesenchymal and Hofbauer cells. Adjustment for cellular composition reduced preeclampsia-associated differentially expressed genes (log 2 fold-change cutoff = 0.1, FDR < 0.05) from 1154 to 0, whereas downregulation of mitochondrial biogenesis, aerobic respiration, and ribosome biogenesis were robust to cell type adjustment, suggesting direct changes to these pathways. Cellular composition mediated a substantial proportion of the association between preeclampsia and FLT1 (37.8%, 95% CI [27.5%, 48.8%]), LEP (34.5%, 95% CI [26.0%, 44.9%]), and ENG (34.5%, 95% CI [25.0%, 45.3%]) overexpression. Our findings indicate substantial placental cellular heterogeneity in preeclampsia contributes to previously observed bulk gene expression differences. This deconvolution reference lays the groundwork for cellular heterogeneity-aware investigation into placental dysfunction and adverse birth outcomes., (© 2023. The Author(s).)

Purpose of Review: Review human literature on the relationship between prenatal exposure to per- and polyfluoroalkyl substances (PFAS) and epigenetic modifications in infants, children, and adolescents < 18 years of age., Recent Findings: Eleven studies were identified, with study populations located in the U.S., Taiwan, Japan, and the Kingdom of Denmark. Many studies (n = 5) were cross-sectional, with PFAS exposure and epigenetic outcomes measured in the same tissue collected at delivery via cord blood or dried newborn blood spots. The other six studies were prospective, with prenatal PFAS measured on maternal blood during pregnancy and DNA methylation (DNAm) assessed in cord blood and childhood peripheral leukocytes (n = 1 study). Epigenetic marks of interest included global DNAm measures (LINE-1, Alu, and an ELISA-based method), candidate genes (IFG2, H19, and MEST), and epigenome-wide DNA methylation via array-based methods (Infinium 450 K and EPIC). Two studies using array-based methods employed discovery and validation paradigms, in which a small subset of loci (n = 6 and n = 4) were replicated in the discovery population. One site (TNXB) was a hit in two independent studies. Collectively, loci associated with PFAS were in regions involved in growth and development, lipid metabolism, and nutrient metabolism. There is moderate human evidence supporting associations of prenatal PFAS exposure on DNAm at birth, with one study suggesting sustained effects into childhood. Future studies are warranted to link PFAS-associated DNAm to health outcomes, as well as to investigate the role of other epigenetic marks such as hydroxymethylation, miRNA expression, and histone modifications., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Mercury (Hg) exposure is a public health problem worldwide that is now being addressed through the Minamata Convention on Mercury. Fish containing methylmercury and dental amalgam containing elemental Hg are the major sources of exposure for most populations. There is some evidence that methylmercury impacts cardiovascular and metabolic health, primarily in populations with high exposure levels. Studies of elemental Hg and these outcomes are relatively rare. We aimed to examine associations between Hg exposure (both elemental and methylmercury) and blood pressure, as well as cholesterol and triglyceride levels. In 2012, we recruited dental professionals attending the Health Screening Program at the American Dental Association (ADA) Annual Session in California. Total Hg levels in hair and blood samples were analyzed as indicators of methylmercury exposure and in urine as an indicator of primarily elemental Hg exposure (n = 386; mean ± sd age 55 ± 11 years). We measured blood pressure (systolic and diastolic) and lipid profiles (total cholesterol, high-density lipoprotein cholesterol [HDL], low-density lipoprotein cholesterol [LDL] and triglycerides). The geometric means (geometric standard deviations) for blood, hair, and urine Hg were 3.64 (2.39) μg/L, 0.60 (2.91) μg/g, and 1.30 (2.44) μg/L, respectively. For every one μg/L increase in specific gravity-adjusted urine Hg, LDL increased by 2.31 mg/dL (95% CI = 0.09, 4.54), in linear regression adjusting for BMI, race, sex, polyunsaturated fatty acid intake from fish consumption, smoking status, and use of cholesterol-lowering medication. No significant associations between Hg biomarkers and blood pressure or hair or blood Hg with lipid levels were observed. Results suggest that elemental Hg exposure may influence LDL concentrations in adults with low-level exposure, and this relationship merits further study in other populations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: Emerging research has shed light on the potential impact of environmental toxicants on sleep health, however, it remains unclear if these associations exist during adolescence and whether associations differ by sex. This study aimed to examine associations between phthalates, parabens, and phenols on adolescent sleep health using cross-sectional data from 470 participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) study., Material and Methods: In 2015, spot urine samples were analyzed for exposure biomarkers of 14 phthalate metabolites, seven phenol, and four paraben analytes. Over seven consecutive days, sleep duration, midpoint, and fragmentation were assessed with wrist-actigraphy. We examined associations between summary phthalates, individual phthalate metabolites, and phenol and paraben analytes with mean weekday sleep duration, midpoint, and fragmentation using linear regression models adjusted for specific-gravity and sex, age, pubertal status, smoking and alcohol behavior, physical activity, and screen time., Results: Mean (SD) age was 13.8 (2.1) years; 53.5 % were female. Σ Plastic - summary measure for toxicants from plastic sources - and Σ DEHP and its metabolites, were associated with longer sleep duration in the unstratified sample. To illustrate, every 1-unit log increase in Σ DEHP was associated with 7.7 min (95 % CI: 0.32, 15.1; p < 0.05) longer duration. Summary measures of toxicants from plastic sources, personal care products, anti-androgenic toxicants, and multiple individual phthalates, phenols, and parabens were associated with later midpoint. The midpoint associations were largely female-specific. There were no associations with sleep fragmentation., Conclusions: Higher EDC exposure may be related to longer sleep duration and later sleep timing during adolescence, and associations may vary by toxicant and according to sex., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Purpose: Early literacy skills are key indicators of future reading development for young dual language learners (DLLs). Additionally, emerging evidence indicates that young children's executive function (EF) skills are uniquely associated with elementary school reading outcomes (Ribner et al., 2017). Therefore, the purpose of this pilot study was to evaluate the potential for embedding strategies to support EF development within evidence-based early language and literacy instruction for young DLLs., Method: Sixty-nine preschool DLLs were randomly assigned to one of three treatment groups: a business-as-usual control group (BAU), a group that received early literacy instruction only (EL group), and a group that received early literacy instruction with embedded EF strategies (EL + EF group). The intervention focused on improving children's early literacy skills, including letter-name knowledge, phonological awareness, and oral language. Children completed assessments of early literacy and EF immediately before and after the intervention., Results: The EL and EL + EF groups significantly outperformed the BAU control group for two early literacy outcomes, and effects of evidence-based early literacy instruction were strongest for children with poor EF skills. Results indicated that there were no significant differences between the EL + EF and EL groups., Conclusions: This pilot study indicated that there was no significant benefit to adding supports for EF skills within evidence-based early literacy instruction. Additional research is needed with larger samples to replicate observed effects., Supplemental Material: https://doi.org/10.23641/asha.21834465.

DNA methylation (DNAm) is a plausible mechanism underlying cardiometabolic abnormalities, but evidence is limited among youth. This analysis included 410 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to two time points in late childhood/adolescence. At Time 1, DNAm was quantified in blood leukocytes at long interspersed nuclear elements (LINE-1), H19 , and 11β-hydroxysteroid dehydrogenase type 2 ( 11β-HSD-2 ), and at Time 2 in peroxisome proliferator-activated receptor alpha ( PPAR-α ). At each time point, cardiometabolic risk factors were assessed including lipid profiles, glucose, blood pressure, and anthropometry. Linear mixed effects models were used for LINE-1, H19 , and 11β-HSD-2 to account for the repeated-measure outcomes. Linear regression models were conducted for the cross-sectional association between PPAR-α with the outcomes. DNAm at LINE-1 was associated with log glucose at site 1 [β = -0.029, p = 0.0006] and with log high-density lipoprotein cholesterol at site 3 [β = 0.063, p = 0.0072]. 11β-HSD-2 DNAm at site 4 was associated with log glucose (β = -0.018, p = 0.0018). DNAm at LINE-1 and 11β-HSD-2 was associated with few cardiometabolic risk factors among youth in a locus-specific manner. These findings underscore the potential for epigenetic biomarkers to increase our understanding of cardiometabolic risk earlier in life.

Importance: Preeclampsia, gestational hypertension, and gestational diabetes, the most common pregnancy complications, are associated with substantial morbidity and mortality in mothers and children. Little is known about the biological processes that link the occurrence of these pregnancy complications with adverse child outcomes; altered biological aging of the growing fetus up to birth is one molecular pathway of increasing interest., Objective: To evaluate whether exposure to each of these 3 pregnancy complications (gestational diabetes, gestational hypertension, and preeclampsia) is associated with accelerated or decelerated gestational biological age in children at birth., Design, Setting, and Participants: Children included in these analyses were born between 1998 and 2018 and spanned multiple geographic areas of the US. Pregnancy complication information was obtained from maternal self-report and/or medical record data. DNA methylation measures were obtained from blood biospecimens collected from offspring at birth. The study used data from the national Environmental Influences on Child Health Outcomes (ECHO) multisite cohort study collected and recorded as of the August 31, 2021, data lock date. Data analysis was performed from September 2021 to December 2022., Exposures: Three pregnancy conditions were examined: gestational hypertension, preeclampsia, and gestational diabetes., Main Outcomes and Measures: Accelerated or decelerated biological gestational age at birth, estimated using existing epigenetic gestational age clock algorithms., Results: A total of 1801 child participants (880 male [48.9%]; median [range] chronological gestational age at birth, 39 [30-43] weeks) from 12 ECHO cohorts met the analytic inclusion criteria. Reported races included Asian (49 participants [2.7%]), Black (390 participants [21.7%]), White (1026 participants [57.0%]), and other races (92 participants [5.1%]) (ie, American Indian or Alaska Native, Native Hawaiian or other Pacific Islander, multiple races, and other race not specified). In total, 524 participants (29.0%) reported Hispanic ethnicity. Maternal ages ranged from 16 to 45 years of age with a median of 29 in the analytic sample. A range of maternal education levels, from less than high school (260 participants [14.4%]) to Bachelor's degree and above (629 participants [34.9%]), were reported. In adjusted regression models, prenatal exposure to maternal gestational diabetes (β, -0.423; 95% CI, -0.709 to -0.138) and preeclampsia (β, -0.513; 95% CI, -0.857 to -0.170), but not gestational hypertension (β, 0.003; 95% CI, -0.338 to 0.344), were associated with decelerated epigenetic aging among exposed neonates vs those who were unexposed. Modification of these associations, by sex, was observed with exposure to preeclampsia (β, -0.700; 95% CI, -1.189 to -0.210) and gestational diabetes (β, -0.636; 95% CI, -1.070 to -0.200), with associations observed among female but not male participants., Conclusions and Relevance: This US cohort study of neonate biological changes related to exposure to maternal pregnancy conditions found evidence that preeclampsia and gestational diabetes delay biological maturity, especially in female offspring.

Environmental contaminants such as the metal lead (Pb) are associated with cardiovascular disease, but the underlying molecular mechanisms are poorly understood. In particular, little is known about how exposure to Pb during early development impacts the cardiac epigenome at any point across the life course and potential differences between sexes. In a mouse model of human-relevant perinatal exposures, we utilized RNA-seq and Enhanced Reduced Representation Bisulfite Sequencing (ERRBS) to investigate the effects of Pb exposure during gestation and lactation on gene expression and DNA methylation, respectively, in the hearts of male and female mice at weaning. For ERRBS, we identified differentially methylated CpGs (DMCs) or differentially methylated 1000 bp regions (DMRs) based on a minimum absolute change in methylation of 10% and an FDR < 0.05. For gene expression data, an FDR < 0.05 was considered significant. No individual genes met the FDR cutoff for gene expression; however, we found that Pb exposure leads to significant changes in the expression of gene pathways relevant to cardiovascular development and disease. We further found that Pb promotes sex-specific changes in DNA methylation at hundreds of gene loci (280 DMCs and 99 DMRs in males, 189 DMCs and 121 DMRs in females), and pathway analysis revealed that these CpGs and regions collectively function in embryonic development. In males, differential methylation also occurred at genes related to immune function and metabolism. We then investigated whether genes exhibiting differential methylation at weaning were also differentially methylated in hearts from a cohort of Pb-exposed mice at adulthood. We found that a single gene, Galnt2, showed differential methylation in both sexes and time points. In a human cohort investigating the influence of prenatal Pb exposure on the epigenome, we also observed an inverse association between first trimester Pb concentrations and adolescent blood leukocyte DNA methylation at a locus in GALNT2, suggesting that this gene may represent a biomarker of Pb exposure across species. Together, these data, across two time points in mice and in a human birth cohort study, collectively demonstrate that Pb exposure promotes sex-specific programming of the cardiac epigenome, and provide potential mechanistic insight into how Pb causes cardiovascular disease.

Many studies implicate mitochondrial dysfunction in the development and progression of numerous chronic diseases. Mitochondria are responsible for most cellular energy production, and unlike other cytoplasmic organelles, mitochondria contain their own genome. Most research to date, through investigating mitochondrial DNA copy number, has focused on larger structural changes or alterations to the entire mitochondrial genome and their role in human disease. Using these methods, mitochondrial dysfunction has been linked to cancers, cardiovascular disease, and metabolic health. However, like the nuclear genome, the mitochondrial genome may experience epigenetic alterations, including DNA methylation that may partially explain some of the health effects of various exposures. Recently, there has been a movement to understand human health and disease within the context of the exposome, which aims to describe and quantify the entirety of all exposures people encounter throughout their lives. These include, among others, environmental pollutants, occupational exposures, heavy metals, and lifestyle and behavioral factors. In this chapter, we summarize the current research on mitochondria and human health, provide an overview of the current knowledge on mitochondrial epigenetics, and describe the experimental and epidemiologic studies that have investigated particular exposures and their relationships with mitochondrial epigenetic modifications. We conclude the chapter with suggestions for future directions in epidemiologic and experimental research that is needed to advance the growing field of mitochondrial epigenetics., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The accumulation of every day exposures can impact health across the life course, but our understanding of such exposures is impeded by our ability to delineate the relationship between an individual's early life exposome and later life health effects. Measuring the exposome is challenging. Exposure assessed at a given time point captures a snapshot of the exposome but does not represent the full spectrum of exposures across the life course. In addition, the assessment of early life exposures and their effects is often further challenged by lack of relevant samples and the time gap between exposures and related health outcomes in later life. Epigenetics, specifically DNA methylation, has the potential to overcome these barriers as environmental epigenetic perturbances can be retained through time. In this review, we describe how DNA methylation can be framed in the world of the exposome. We offer three compelling examples of common environmental exposures, including cigarette smoke, the endocrine active compound bisphenol A (BPA), and the metal lead (Pb), to illustrate the application of DNA methylation as a proxy to measure the exposome. We discuss areas for future explorations and current limitations of this approach. Epigenetic profiling is a promising and rapidly developing tool and field of study, offering us a unique and powerful way to assess the early life exposome and its effects across different life stages., Competing Interests: Conflicts of Interest The authors declare that they have no conflicts of interest.

The early-gestational fetal epigenome establishes the landscape for fetal development and is susceptible to disruption via environmental stressors including chemical exposures. Research has explored how cell- and tissue-type-specific epigenomic signatures contribute to human disease, but how the epigenome in each tissue comparatively responds to environmental exposures is largely unknown. This pilot study compared DNA methylation in four previously identified genes across matched cord blood (CB), cord tissue (CT), and placental (PL) samples from 28 mother-infant pairs in tthe Michigan Mother Infant Pairs study; evaluated association between prenatal exposure to bisphenols (BPA, BPF, and BPS) and DNA methylation (DNAm) by tissue type; compared epigenome-wide DNAm of CB and PL; and explored associations between prenatal bisphenol exposures and epigenome-wide DNAm in PL. Bisphenol concentrations were quantified in first-trimester maternal urine. DNAm was assessed at four genes via pyrosequencing in three tissues; epigenome-wide DNAm analysis via Infinium MethylationEPIC array was completed on CB and PL. Candidate gene analysis revealed tissue-specific differences across all genes. In adjusted linear regression, BPA and BPF were associated with DNAm across candidate genes in PL but not CB and CT. Epigenome-wide comparison of matched CB and PL DNAm revealed tissue-specific differences at most CpG sites and modest associations between maternal first-trimester bisphenol exposures and PL but not CB DNAm. These data endorse inclusion of a variety of tissues in prenatal exposure studies. Overlapping and divergent responses in CB, CT, and PL demonstrate their utility in combination to capture a fuller picture of the epigenetic effect of developmental exposures., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Differential item functioning (DIF) is often used to examine validity evidence of alternate form test accommodations. Unfortunately, traditional approaches for evaluating DIF are prone to selection bias. This article proposes a novel DIF framework that capitalizes on regression discontinuity design analysis to control for selection bias. A simulation study was performed to compare the new framework with traditional logistic regression, with respect to Type I error and power rates of the uniform DIF test statistics and bias and root mean square error of the corresponding effect size estimators. The new framework better controlled the Type I error rate and demonstrated minimal bias but suffered from low power and lack of precision. Implications for practice are discussed., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Objectives: Firefighters face exposures associated with adverse health outcomes including risk for multiple cancers. DNA methylation, one type of epigenetic regulation, provides a potential mechanism linking occupational hazards to adverse health outcomes. We hypothesised that DNA methylation profiles would change in firefighters after starting their service and that these patterns would be associated with occupational exposures (cumulative fire-hours and fire-runs)., Methods: We profiled DNA methylation with the Infinium MethylationEPIC in blood leucocytes at two time points in non-smoking new recruits: prior to live fire training and 20-37 months later. Linear mixed effects models adjusted for potential confounders were used to identify differentially methylated CpG sites over time using data from 50 individuals passing all quality control., Results: We report 680 CpG sites with altered methylation (q value <0.05) including 60 with at least a 5% methylation difference at follow-up. Genes with differentially methylated CpG sites were enriched in biological pathways related to cancers, neurological function, cell signalling and transcription regulation. Next, linear mixed effects models were used to determine associations between occupational exposures with methylation at the 680 loci. Of these, more CpG sites were associated with fire-runs (108 for all and 78 for structure-fires only, q<0.05) than with fire-hours (27 for all fires and 1 for structure fires). These associations were independent of time since most recent fire, suggesting an impact of cumulative exposures., Conclusions: Overall, this study provides evidence that DNA methylation may be altered by fireground exposures, and the impact of this change on disease development should be evaluated., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Prenatal phthalates exposures have been related to adiposity in peripuberty in a sex-specific fashion. Untargeted metabolomics analysis to assess circulating metabolites offers the potential to characterize biochemical pathways by which early life exposures influence the development of cardiometabolic risk during childhood and adolescence, prior to becoming evident in clinical markers., Methods: Among mother-child dyads from the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) birth cohort, we measured 9 phthalate metabolites and bisphenol A in maternal spot urine samples obtained during each trimester of pregnancy, corrected for urinary specific gravity and natural log-transformed. In 110 boys and 124 girls aged 8-14 years, we used a mass-spectrometry based untargeted metabolomics platform to measure fasting serum metabolites, yielding 572 annotated metabolites. We estimated the associations between trimester-specific urinary toxicants and each serum metabolite, among all children or stratified by sex and adjusting for child age, BMI z-score, and pubertal onset. We accounted for multiple comparisons using a 10% false discovery rate (q<0.1)., Results: Associations between exposures and metabolites were observed among all children and in sex-stratified analyses (q<0.1). First trimester MEP, MiBP, and MCPP were associated with decreased 2-deoxy-D-glucose among all children. Among girls, third trimester concentrations of MECPP, MEHHP, MEHP, and MCPP were associated with 15, 13, 1, and 10 metabolites, respectively, including decreased choline and increased acylcarnitines and saturated FAs (FA). Among boys, third trimester MIBP was positively associated with 9 features including long chain saturated FAs, and second trimester MBzP was inversely associated with thyroxine., Conclusions: Metabolomics biomarkers may reflect sex- and exposure timing-specific responses to prenatal phthalate exposures manifesting in childhood that may not be detected using standard clinical markers of cardiometabolic risk., Competing Interests: The authors have declared that no competing interests exist.

Wildfire events are increasing across the globe. The smoke generated as a result of this changing fire landscape is potentially more toxic than air pollution from other ambient sources, according to recent studies. This is especially concerning for populations of humans or animals that live downwind of areas that burn frequently, given that ambient exposure to wildfire smoke cannot be easily eliminated. We hypothesized that a significant indoor air pollution risk existed for laboratory animal facilities located proximal to fire-prone areas. Here, we measured real time continuous outdoor and indoor air quality for 28 days at a laboratory animal facility located in the Rocky Mountain region. We demonstrated that during a wildfire event, the indoor air quality of this animal facility is influenced by ambient smoke events. The daily average indoor fine particulate matter value in an animal room exceeded the Environmental Protection Agency's ambient annual standard 14% of the time and exceeded the World Health Organization's ambient annual guideline 71% of the time. We further show that specialized cage filtration systems are capable of mitigating air pollution penetrance and could improve an animal's microenvironment. The potential effects for laboratory animal physiology that occur in response to the exposure levels and durations measured in this study remain to be determined; yet, even acute wildfire exposure events have been previously correlated with significant differences in gene regulatory and metabolic processes in vivo. We believe these findings warrant consideration for indoor laboratory animal facility air quality monitoring and development of smoke exposure prevention and response protocols, especially among facilities located downwind of fire-prone landscapes.