DNA methylation in blood cells is associated with cortisol levels in offspring of mothers who had prenatal post‐traumatic stress disorder

Prenatal maternal life adversity impacts on learning and memory in offspring: implication to transgenerational epigenetic inheritance

Maternal stress exposure during pregnancy is known to affect offspring behavior, including learning and memory. We hypothesized that maternal stress-induced changes transmit this effect through maternal line mediated transgenerational epigenetic inheritance. To test our hypothesis, pregnant rats (F0) were undisturbed (Control, Ctrl)/exposed to social stress during gestational days (GD) 16-18 (PMS)/exposed to social stress and treated with oxytocin during GD-16 to 18 (PMS+OXT). Subsequently, F1 female offspring from Ctrl, PMS, and PMS+OXT were mated with Ctrl F1 males to examine maternal line mediated transgenerational impacts. Female animals (F1 and F2) were subjected to behavioral test and the levels of global H3K4me2/H3K4me3 methylation, methylation in the CRH promoter, expression of Crh, Crh receptors (Crhr1, Crhr2), and BDNF were determined. It was found that prenatal maternal stress (PMS) reduced reference and working memory in F1 and F2 offspring, increased global and specific H3K4me2, H3K4me3 methylation in the CRH promoter, expression of Crh, Crh receptors, and corticosterone (CORT), and down-regulated the expression of pro-and mature BDNF by differentially regulating Bdnf transcripts III, IV and VI in the amygdala. Oxytocin exposure reduced PMS-induced global and specific H3K4me2/3 changes, which repressed the expression of Crh, Crh receptors, reduced CORT levels, up-regulated the expression of pro-BDNF and mature BDNF, and improved memory in F1 and F2 offspring. Collectively, our study revealed that PMS reduced reference and working memory performance in F1 and F2 offspring through maternal line transgenerational inheritance of H3K4me2, H3K4me3 methylation, and associated mechanisms that regulate BDNF expression and synaptic plasticity.

Adverse fetal and neonatal impact of war conflicts during pregnancy: A systematic review

The aim of the present study was to establish the fetal and neonatal impact of war conflicts during pregnancy. A systematic review was conducted according to The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and relevant publications available in the PubMed, Scopus and Web of Science, and PsycINFO databases. Primary and quantitative studies were eligible for inclusion. To be included, studies had to be redacted in Spanish or English and evaluate maternal exposure to a war or terrorist attack during pregnancy, with consideration being given of the consequences of this for fetal and/or neonatal development. Systematic, narrative and exploratory literature reviews were excluded, as were meta-analyses and studies in which the sample differed from the sample of interest, the focus was on other stressful factors that differed from a war conflict and the consequences examined did not comprise the impact of a war during pregnancy on the fetus or neonate. The methodological quality of included articles was assessed using the CASP (Critical Appraisal Skills Programme) tool. A total of 28 articles were included, with an included sample of n = 664,980 mother-infant dyads, exposed to war conflicts. The adverse impact of prenatal stress suffered by mothers during periods of war revealed that, (1) in the short-term, babies were at greater risk of having a low birth weight and impinged length and being born prematurely, whilst mothers were more likely to suffer a miscarriage. (2) In the long-term, babies exposed to war during the prenatal period had a higher risk of experiencing alterations to their neurodevelopment, mental disorders and pathophysiological diseases. The stress suffered by mothers during the prenatal period can bring about a number of negative consequences over both the short- and long-term in babies, especially, in terms of their physical and neurological development. It is important to conduct further research on the topic with the aim of detecting and treating the early stages of maternal psychological illnesses experienced during pregnancy due to war conflict and, in this way, achieve benefits for pregnant women and future generations.

Detection of DNA methylation from buccal swabs using nanopore sequencing to study stunting

Stunting is the result of chronic malnutrition due to the lack of micronutrient-based methyl donors required for epigenetic programming during the first 1000 days of life. Methylation studies using bisulfite conversion from blood DNA are invasive and may not be practical for large-scale epidemiological investigation or nutrition intervention programs. Buccal epithelial methylation may reflect early germline methylation. Therefore, buccal cells can serve as convenient sample sources to collect biomarkers associated with the risk of stunting. This study aims to describe the feasibility of nanopore adaptive sampling in detecting DNA methylation from children's buccal DNA. We used adaptive sampling of Oxford Nanopore Technology on barcoded samples to describe differential methylation associated with malnutrition. Overall, the level of 5-methylcytosine (5mC) was lower in stunted children than in normal children. We also found differentially methylated regions at the MIR6724 and RNA45SN1 gene loci on chromosome 21, which was higher in stunted children than in normal children. We described and detected differential DNA methylation in the locus previously not known to be associated with stunting. Interestingly, this locus on chromosome 21 has been implicated in the stunted phenotype of Down syndrome.

Maternal adverse childhood experiences (ACEs) and offspring imprinted gene DMR methylation at birth

Adverse childhood experiences (ACEs) contribute to numerous negative health outcomes across the life course and across generations. Here, we extend prior work by examining the association of maternal ACEs, and their interaction with financial stress and discrimination, with methylation status within eight differentially methylated regions (DMRs) in imprinted domains in newborns. ACEs, financial stress during pregnancy, and experience of discrimination were self-reported among 232 pregnant women. DNA methylation was assessed at PEG10/SGCE, NNAT, IGF2, H19, PLAGL1, PEG3, MEG3-IG, and DLK1/MEG3 regulatory sequences using pyrosequencing. Using multivariable linear regression models, we found evidence to suggest that financial stress was associated with hypermethylation of MEG3-IG in non-Hispanic White newborns; discrimination was associated with hypermethylation of IGF2 and NNAT in Hispanic newborns, and with hypomethylation of PEG3 in non-Hispanic Black newborns. We also found evidence that maternal ACEs interacted with discrimination to predict offspring PLAGL1 altered DMR methylation, in addition to interactions between maternal ACEs score and discrimination predicting H19 and SGCE/PEG10 altered methylation in non-Hispanic White newborns. However, these interactions were not statistically significant after multiple testing corrections. Findings from this study suggest that maternal ACEs, discrimination, and financial stress are associated with newborn aberrant methylation in imprinted gene regions.

Prenatal exposure to genocide and subsequent adverse childhood events are associated with DNA methylation of SLC6A4, BDNF, and PRDM8 in early adulthood in Rwanda

We investigated associations between prenatal genocidal trauma, including maternal rape, and postnatal adverse childhood experiences (ACEs) on DNA methylation of genes associated with the stress response. In a comparative cross-sectional study of 91 Rwandan young adults, categorized by prenatal exposure to genocide and maternal rape, genocide without rape, and unexposed controls, we analyzed DNA methylation from dried blood spots and assessed ACEs and depression and anxiety symptoms at age 24. Prenatal exposure to maternal rape was associated with DNA methylation changes in BDNF and SLC6A4, with the association in BDNF attenuated after including ACE exposure in the model. Genocide exposure without rape was associated with methylation changes in PRDM8 after adjusting for early adversity. Methylation in BDNF and SLC6A4 correlated with depression and anxiety symptoms. These findings underscore the impact of prenatal and postnatal trauma on DNA methylation and mental wellbeing, emphasizing the need for continued support for survivors in the decades after conflict.

An epigenome-wide study of a needs-based family intervention for offspring of trauma-exposed mothers in Kosovo

INTRODUCTION

Maternal stress and trauma during pregnancy have been shown to influence cortisol levels and epigenetic patterns, including DNA methylation, in the offspring. This study aimed to determine whether a tailor-made family intervention could help reduce cortisol levels in children born to traumatized mothers, and to determine whether it effected offspring DNA methylation. The secondary aim was to determine whether the family intervention influenced DNA methylation aging, a marker of biological aging.

METHODS

A needs-based family intervention was designed to help address relational difficulties and family functioning, and included a focus on family strengths and problem-solving patterns. Women survivors of sexual violence during the Kosovar war in 1998-1999, and their families (children with or without partners) were randomly assigned to 10 sessions of a family therapy over a 3-5-month period, or to a waitlist control group. Both mothers and children completed assessments prior to and after the intervention phase. Children's blood samples collected at these two time points were used to measure cortisol and epigenome-wide DNA methylation patterns (Illumina EPIC array). Cortisol levels, and genome-wide DNA methylation changes pre-/postintervention were compared between children in the intervention and the waitlist groups. DNA methylation age and accelerated biological aging were calculated.

RESULTS

Sixty-two women-child dyads completed the study, 30 were assigned first to the intervention group, and 32 to the waitlist control group. In adjusted linear regression, the family intervention was associated with a significant decline in cortisol levels compared to the waitlist control (β = -124.72, 95% confidence interval [CI]: -197.4 to -52.1, p = .001). Children in the intervention group, compared to the waitlist control group, showed >1% differential methylation degree at 5819 CpG (5'-C-phosphate-G-3') sites across the genome (p < .01), with the largest methylation difference being 21%. However, none of these differences reached genome-wide significant levels. There was no significant difference in DNA methylation aging between the two groups.

CONCLUSION

We find evidence that a tailored family-based intervention reduced stress levels in the children (based on cortisol levels), and modified DNA methylation levels at a number of sites across the genome. This study provides some preliminary evidence to suggest the potential for tailored interventions to help break the intergenerational transmission of trauma, however, large studies powered to detect associations at genome-wide significant levels are needed.

Association of hair cortisol concentration with brain-derived neurotrophic factor gene methylation: The role of sex as a moderator

Hair cortisol concentration (HCC) reflects the long-term activity of the hypothalamus-pituitary-adrenal (HPA) axis in response to stress. Brain-derived neurotrophic factor DNA methylation (BDNF DNAM) may affect HCC, and sex and Val66Met may contribute to this association. Thus, the aim of this study was to investigate the associations between HCC and Brain-derived neurotrophic factor (BDNF) DNAM, and the moderating effects of Val66Met and sex. We recruited 191 healthy young participants (96 women, mean age 23.0 ± 2.6 years) and collected body samples to evaluate HCC, and to determine BDNF DNAM and Val66Met genotypes. We analyzed the effects of BDNF DNAM, sex, and Val66Met on HCC. We also evaluated the associations between BDNF DNAM and HCC in groups separated by sex and genotypes. We found a marked association of BDNF DNAM with HCC across men and women. After dividing the data by sex, a positive correlation of HCC with BDNF DNAM was found only in women. There was no substantial moderation effect of Val66Met genotypes on the association between BDNF DNAM and HCC. Therefore, BDNF DNAM was found to have positive association with HCC only in healthy young women, indicating that sex moderates the association of BDNF DNAM with long-term HPA axis activity.

Family Therapy for Kosovar Mothers Who Experienced Conflict-Related Sexual Violence and Their Children in Postwar Times: A Pilot Randomised Waitlist-Controlled Trial

Women who have experienced conflict-related sexual violence report significant long-term effects, including posttraumatic stress disorder (PTSD), depression and relationship difficulties. Research has demonstrated that maternal trauma is associated with children's behavioural difficulties and challenges in family functioning, such as impaired communication and harsh parenting. This pilot study is aimed at evaluating the preliminary effectiveness of family therapy for Kosovar mothers who experienced conflict-related sexual violence in 1998-1999 and later developed PTSD and their children in improving family functioning and reducing behavioural difficulties in postwar times. Sixty-four mothers were randomised to an intervention group or a waitlist control group. Data was collected during a screening phase, at baseline before intervention initiation, after the intervention group completed family therapy and once the waitlist control group received the intervention. Generalised linear mixed models were used to analyse group differences in family functioning and children's behaviours over time. At follow-up, mothers in the intervention group reported improved family functioning. However, mothers in the waitlist control group reported significantly fewer behavioural difficulties than mothers in the intervention group before the control group had started family therapy. There was no significant interaction between group condition and time for child-rated family functioning. Overall, this pilot study suggests that family therapy could be effective in reducing the effects of intergenerational trauma related to PTSD and conflict-related sexual violence. Future research should evaluate the long-term effects of family therapy to assess if immediate effects were maintained.

Epigenetic Alterations in Post-Traumatic Stress Disorder: Comprehensive Review of Molecular Markers

Background

Post-traumatic stress disorder (PTSD) can occur after a traumatic event. PTSD is characterized by nightmares, flashbacks and avoidance of stressors. It currently affects 2-8% of the population, with military personnel particularly susceptible. Studies show that environmental stressors can induce various epigenetic changes that shape the PTSD phenotype. Despite the significant impact of epigenetic factors on PTSD symptoms and susceptibility, they have not been widely discussed in the literature. This review focuses on describing epigenetic mechanisms in PTSD, especially DNA methylation, chromatin regulation, and noncoding RNA.

Summary

The article includes relevant studies published from 2013 to 2023, excluding non-English-language studies or studies with insufficient data. This review investigated gene methylation changes in association with PTSD, including those related to the hypothalamic-pituitary-adrenal axis, brain-derived neurotrophic factor, neurotransmitters, and immune system functioning, as well as the role of histones and regulatory noncoding RNAs.

Key Messages

Epigenetic alterations play a crucial role in shaping PTSD susceptibility, symptomatology, and long-term outcomes, highlighting their potential as important markers and therapeutic targets. Understanding these alterations can aid in developing clinical strategies to better predict, prevent, and treat PTSD. However, further large-scale longitudinal studies are needed to establish the temporal relationship between epigenetic changes and the onset of PTSD, as well as to classify other potential epigenetic mechanisms.

Differential impact of prenatal PTSD symptoms and preconception trauma exposure on placental NR3C1 and FKBP5 methylation

Perinatal stress is associated with altered placental methylation, which plays a critical role in fetal development and infant outcomes. This proof-of-concept pilot study investigated the impact of lifetime trauma exposure and perinatal PTSD symptoms on epigenetic regulation of placenta glucocorticoid signaling genes (NR3C1 and FKBP5). Lifetime trauma exposure and PTSD symptoms during pregnancy were assessed in a racially/ethnically diverse sample of pregnant women (N = 198). Participants were categorized into three groups: (1) No Trauma (-T); (2) Trauma, No Symptoms (T - S); and (3) Trauma and Symptoms (T + S). Placental tissue was analyzed via bisulfite pyrosequencing for degree of methylation at the NR3C1 promoter and FKBP5 regulatory regions. Analyses of covariance were used to test group differences in percentages of NR3C1 and FKBP5 methylation overall and at each CpG site. We found a significant impact of PTSD symptoms on placental NR3C1 methylation. Compared to the -T group, the T + S group had greater NR3C1 methylation overall and at CpG6, CpG8, CpG9, and CpG13, but lower methylation at CpG5. The T + S group had significantly higher NR3C1 methylation overall and at CpG8 compared to the T - S group. There were no differences between the T - S group and - T group. Additionally, no group differences emerged for FKBP5 methylation. Pregnant trauma survivors with PTSD symptoms exhibited differential patterns of placental NR3C1 methylation compared to trauma survivors without PTSD symptoms and pregnant women unexposed to trauma. Results highlight the critical importance of interventions to address the mental health of pregnant trauma survivors.

Epigenetic Changes Associated with Different Types of Stressors and Suicide

Stress is associated with various epigenetic changes. Some stress-induced epigenetic changes are highly dynamic, whereas others are associated with lasting marks on the epigenome. In our study, a comprehensive narrative review of the literature was performed by investigating the epigenetic changes that occur with acute stress, chronic stress, early childhood stress, and traumatic stress exposures, along with examining those observed in post-mortem brains or blood samples of suicide completers and attempters. In addition, the transgenerational effects of these changes are reported. For all types of stress studies examined, the genes Nr3c1, OXTR, SLC6A4, and BDNF reproducibly showed epigenetic changes, with some modifications observed to be passed down to subsequent generations following stress exposures. The aforementioned genes are known to be involved in neuronal development and hormonal regulation and are all associated with susceptibility to mental health disorders including depression, anxiety, personality disorders, and PTSD (post-traumatic stress disorder). Further research is warranted in order to determine the scope of epigenetic actionable targets in individuals suffering from the long-lasting effects of stressful experiences.