Project description:Background: Prenatal maternal stress (PNMS) predicts a wide variety of behavioral and physical outcomes in the offspring. Although epigenetic processes may be responsible for PNMS effects, human research is hampered by the lack of experimental methods that parallel controlled animal studies. Disasters, however, provide natural experiments that can provide models of prenatal stress. Methods: Five months after the 1998 Quebec ice storm we recruited women who had been pregnant during the disaster and assessed their degrees of objective hardship and subjective distress. Thirteen years later, we investigated DNA methylation profiling in T cells obtained from 36 of the children, and compared selected results with those from saliva samples obtained from the same children at age 8. Results: Prenatal maternal objective hardship was correlated with DNA methylation levels in 1675 CGs affiliated with 957 genes predominantly related to immune function; maternal subjective distress was uncorrelated. DNA methylation changes in SCG5 and LTA, both highly correlated with maternal objective stress, were comparable in T cells, peripheral blood mononuclear cells (PBMCs) and saliva cells. Conclusions: These data provide first evidence in humans supporting the conclusion that PNMS results in a lasting, broad, and functionally organized DNA methylation signature in several tissues in offspring. By using a natural disaster model, we can infer that the epigenetic effects found in Project Ice Storm are due to objective levels of hardship experienced by the pregnant woman rather than to her level of sustained distress. Bisulphite converted DNA from the 34 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip v1.2
Project description:Background: Prenatal maternal stress (PNMS) predicts a wide variety of behavioral and physical outcomes in the offspring. Although epigenetic processes may be responsible for PNMS effects, human research is hampered by the lack of experimental methods that parallel controlled animal studies. Disasters, however, provide natural experiments that can provide models of prenatal stress. Methods: Five months after the 1998 Quebec ice storm we recruited women who had been pregnant during the disaster and assessed their degrees of objective hardship and subjective distress. Thirteen years later, we investigated DNA methylation profiling in T cells obtained from 36 of the children, and compared selected results with those from saliva samples obtained from the same children at age 8. Results: Prenatal maternal objective hardship was correlated with DNA methylation levels in 1675 CGs affiliated with 957 genes predominantly related to immune function; maternal subjective distress was uncorrelated. DNA methylation changes in SCG5 and LTA, both highly correlated with maternal objective stress, were comparable in T cells, peripheral blood mononuclear cells (PBMCs) and saliva cells. Conclusions: These data provide first evidence in humans supporting the conclusion that PNMS results in a lasting, broad, and functionally organized DNA methylation signature in several tissues in offspring. By using a natural disaster model, we can infer that the epigenetic effects found in Project Ice Storm are due to objective levels of hardship experienced by the pregnant woman rather than to her level of sustained distress.
Project description:Fetal alcohol spectrum disorder (FASD) is a common developmental behavioral disorder caused by maternal drinking during pregnancy. Children born with FASD often face additional stress, particularly maternal separation that adds yet additional deficits. The mechanism associated with this phenomenon is not known. Using a mouse model, prenatal ethanol exposure and maternal separation stress have resulted in behavioral deficits and the combination of treatments results in more than additive effects. In addition, behavioral alterations are associated with changes in hippocampal gene expression that persist into adulthood. What initiates and maintains these changes remains to be established and forms the focus of this research. Specifically, MeDIP-Seq was used to assess how changes in promoter DNA methylation are affected by the combination of prenatal ethanol exposure and maternal separation stress with the potential to affect gene expression. The novel results show different sets of genes implicated by promoter DNA methylation affected by both treatments independently, and a relatively unique set of genes affected by the combination of treatments. Prenatal ethanol exposure leads to altered promoter DNA methylation at genes important for brain function and transcriptional regulation. Maternal separation stress leads to changes at genes important for histone methylation and immune response, and the combination of two treatments results in DNA methylation changes at genes important for neuronal migration and immune response. Our dual results on gene expression and DNA methylation from the same samples have allowed comparison of the two observations. There is minimal reciprocal overlap between changes in promoter DNA methylation and gene expression, although overlapping genes tend to be critical for brain development and function. These results suggest that epigenetic mechanisms beyond promoter DNA methylation must be involved in lasting gene expression alterations leading to behavioral deficits implicated in FASD.
Project description:BACKGROUND & AIMS: Inflammatory Bowel Diseases (IBD), including Crohnâ??s disease and ulcerative colitis, are chronic illnesses that are thought to develop secondary to a pathologic interaction between the immune system and the intestinal microflora that is manifested by the gut mucosa. IBD has been recognized as disorders in which developmental epigenetic changes, such as DNA methylation, may play an important pathogenic role. DNA methylation can be influenced in mammals by dietary exposures. A methyl-donor diet has been specifically found to be effective in inducing permanent changes in DNA methylation at certain genomic loci in murine models. Importantly, the methyl-donor substances utilized are routinely incorporated into prenatal micronutrient supplements for humans. In this study we addressed whether maternal exposure to a methyl-donor diet induces prolonged alterations in offspring colitis susceptibility and whether it leads to stable colonic mucosal epigenetic changes and gene expression alterations in mice. We also assessed whether the maternal methyl-donor diet induced persistent changes in the colonic microbiota in the offspring. METHODS: Colonic mucosa from offspring of mothers fed a methyl donor diet (MD) or control diet was interrogated by methylation specific amplification microarray (MSAM) at postnatal day 30 (P30) and P90 to screen for changes in DNA methylation, with bisulfite pyrosequencing validation. Transcriptomic changes in the same tissue were analyzed by microarray expression profiling and real time RT-PCR. The mucosal microbiome was studied by high throughput, detailed pyrosequencing of 16S rRNA. RESULTS: MD exposure during prenatal and early development lead to a significant increase in colitis susceptibility that persisted even after 69 days of diet reversal (P90). MD exposure also influenced DNA methylation and expression at select genomic loci. Overlap between DNA methylation and gene expression changes was confirmed at Ppara, a gene previously implicated in murine colitis. Metagenomic analyses failed to reveal consistent bacteriomic differences between the P30 and P90 age groups. CONCLUSIONS: Prenatal and early developmental exposure to MD induces increased colitis susceptibility, mucosal epigenomic, and transcriptomic changes that do not appear to associate with consistent microbiomic alterations. These findings underscore the importance of maternal nutrition on offspring colitis susceptibility in mammals and implicate the importance of the associated mucosal epigenetic modification. Our results bare potentially significant public health relevance as well. 4 independent MD versus control comparisons at P90 were performed as follows. RNA (0.4ug) samples were processed and labelled with Cy3 and Cy5 (Quick Amp labelling kit, two color, Agilent technologies) and 4 independent P90 MD to P90 control comparisons were done on Agilent technologies 4x44k whole genomic expression microarray G2519F, Amadid:014868)
Project description:Background: How prenatal smoke exposure affects DNA methylation leading to atopic disorders remains to be addressed. Epigenetic biomarkers informative of prenatal smoke exposure and atopic disorders are wanting. Since most children suffering from atopic dermatitis (AD) continue to develop asthma later in life, we explored whether prenatal smoke exposure e induces DNA methylation and searched for predictive epigenetic biomarkers for smoke related atopic disorders. Methods: Methylation differences associated with smoke exposure were screened by Illumina methylation panel for children from the Taiwan birth panel study cohort initially. Information about development of atopic dermatitis (AD) and risk factors were collected. Cord blood cotinine levels were measured to represent prenatal smoke exposure. CpG loci that demonstrated a statistically significant difference in methylation were validated by methylation-dependent fragment separation (MDFS). Differential methylation in three genes (TSLP, GSTT1, and CYB5R3) was identified through the screen and their functions were investigated. Results: Among these, only thymic stromal lymphopoietin (TSLP) gene displayed significant difference in promoter methylation percentage after being validated by MDFS (p=0.029). TSLP gene was further investigated in a larger sample of 92 children from the cohort. Methylation status of the TSLP 5′-CpG island (CGI) was found to be significantly associated with prenatal smoke exposure (OR=3.59, 95%CI=1.49-8.64; cotinine level 0.10 ng/ml, sensitivity= 77%; specificity = 61%) and with AD (OR=4.77, 95%CI=1.47-15.53). The degree of TSLP 5′CGI methylation inversely correlated with TSLP protein expression levels (per unit: β=-6.69 ng/ml; 95% CIs, -12.80~-0.59; p=0.032). Conclusions: The effect of prenatal tobacco smoke exposure on the risk for AD may be mediated through DNA methylation. Cord blood methylated TSLP 5′CGI may be a potential epigenetic biomarker for environmentally-related atopic disorders. The buffy coat and plasma samples were separated and stored at −80°C. DNA (100 ng-500 ng) was extracted from cord white blood cells. Microarrays have been performed to investigate fourteen samples, which were classified as two groups according to cotinine exposure dosage (7 versus 7 : high exposure verses low exposure).
Project description:Background: During gestation, stressors to the fetus, including viral exposure or maternal psychological distress, can fundamentally alter the neonatal epigenome, and may be associated with long-term impaired developmental outcomes. The impact of in utero exposure to the COVID-19 pandemic on the newborn epigenome has yet to be described. Methods: This study aimed to determine whether there are unique epigenetic signatures in newborns who experienced otherwise healthy pregnancies that occurred during the COVID-19 pandemic (Project RESCUE). The pre-pandemic control and pandemic cohorts (Project RESCUE) included in this study are part of a prospective observational and longitudinal cohort study that evaluates the impact of elevated prenatal maternal stress during the COVID-19 pandemic on early childhood neurodevelopment. Using buccal swabs collected at birth, differential DNA methylation analysis was performed using the Infinium MethylationEPIC arrays and linear regression analysis. Pathway analysis and gene ontology enrichment were performed on resultant gene lists. Results: Widespread differential methylation was found between neonates exposed in utero to the pandemic and pre-pandemic neonates. In contrast, there were no apparent epigenetic differences associated with maternal COVID-19 infection during pregnancy. Differential methylation was observed among genomic sites that underpin important neurological pathways that have been previously reported in the literature to be differentially methylated because of prenatal stress, such as NR3C1. Conclusions: The present study reveals that the onset and continuation of the COVID-19 pandemic has fundamentally altered the epigenomes of newborns born during this time, even in otherwise healthy pregnancies, which should be considered in current and future epigenetic studies and may act as a critical biomarker of stress.
Project description:Adverse childhood experiences (ACEs) have detrimental intergenerational health consequences; however, mechanisms require elucidation. We test the associations among mothers’ ACEs, mothers’ prenatal anxiety and depression symptoms, and DNA methylation (DNAm) in maternal prenatal blood and infant umbilical cord blood. Maternal ACE score was associated with higher prenatal depression (β= 0.84, p=0.004) and anxiety (β = 1.36, p=0.02) symptoms and lower rates of secure attachment at 3 months (OR= 0.52 p=0.003). Prenatal depression (OR= 0.92, p=0.194) and anxiety (OR= 0.94, p= 0.072) were not correlated with infant attachment. Results from the regression of epigenetic age acceleration in maternal prenatal blood on maternal ACE score were: β =0.49, p= 0.09. Regressing epigenetic age in cord blood on prenatal depression yielded: β = -0.10, p=0.07 and on anxiety yielded β =-0.05, p=0.07. No CMR was associated with maternal ACE score at the FDR-corrected p<.05 level. ACE-associated DNAm variation was enriched for genes related to nervous and reproductive systems development. ACEs may affect the next generation through maternal mental health, infant attachment, and DNAm.
Project description:The maternal microbiota plays an important role in shaping and priming infant immunity, although the cellular and molecular mechanisms underlying these effects remain obscure. Here we report that prenatal antibiotic exposure caused significant elevation of group 2 innate lymphoid cells (ILC2s) in neonatal lungs, in both cell numbers and functionality. Downregulation of type 1 interferon signaling in ILC2s caused by diminished production of microbiota-derived metabolite butyrate represents the underlying mechanism. Mice lacking butyrate receptor GPR41 (GPR41-/-) or type 1 interferon receptor (Ifnar1-/-) recapitulated the phenotype of neonatal ILC2s upon maternal antibiotic exposure. Furthermore, prenatal antibiotic exposure induced persistent epigenetic changes in ILC2s and had a long-lasting deteriorative effect on allergic airway inflammation in adulthood. Prenatal supplementation with butyrate ameliorated airway inflammation in adult offspring born to antibiotic-exposed dams. These observations demonstrate an essential role for the maternal microbiota in the control of type 2 innate immunity at the neonatal stage, which provides a therapeutic window for treating asthma in early life.
Project description:Intrauterine exposure to hyperglycemic environment is reported to confer increased metabolic risk in later life, supporting the “developmental origins of health and disease” hypothesis. Epigenetic alterations are suggested as one of the possible underlying mechanisms. We measured DNA methylation using Infinium HumanMethylation450 BeadChip in siblings discordant for maternal gestational diabetes mellitus (GDM), which may allow possible genetic and environmental confounding effects to be reduced. Of the 465,447 CpG sites analyzed, 12 showed differential methylation (false discovery rate < 0.15), including markers within genes associated with monogenic diabetes (HNF4A) or obesity (RREB1). The overall methylation at the HNF4A gene region showed inverse correlations with mRNA expression levels though non-significant. In a gene set enrichment analysis, differentially methylated CpGs-associated genes were involved in metabolism and signal transduction pathways. Our findings implicate epigenetic mechanisms in relation to prenatal exposure to maternal hyperglycemia.
Project description:Noninvasive prenatal diagnosis currently used does not achieve desirable levels of sensitivity and specificity. Recently, fetal methylated DNA biomarkers in maternal whole blood have been explored for noninvasive prenatal detection. However, such efforts cover only chromosomal aneuploidy; fetal methylated DNA biomarkers for detecting single-gene disease remain to be discovered. To address this issue, we systematically screened significantly hypermethylated genes in fetal tissues compared with maternal blood for noninvasive prenatal diagnosis of various inherited diseases. First, Methylated-CpG island recovery assay combined with CpG island array was performed in four maternal peripheral bloods and their corresponding placental tissues. Subsequently, direct bisulfite sequencing and combined bisulfite restriction analysis (COBRA) were carried out to validate the reliability of methylation microarray analysis. As results, 310 significantly hypermethylated genes in fetal tissues were detected by microarray. Two of five randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in fetal tissue samples by direct bisulfite sequencing. All four randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in five independent amniotic fluid samples and five independent chorionic villus samples from 10 pregnant women by CORBA. In conclusions, We found a lot of hypermethylated genes and methylation sites in fetal tissues, some of which have great potential to be developed into molecular markers for noninvasive prenatal diagnosis of monogenic disorders. Further clinical study is warranted to confirm these findings. Paired experiments, placental tissues vs. maternal peripheral bloods. Biological replicates: 4 placental tissues and 4 correspoding maternal peripheral bloods.