Epigenome-wide meta-analysis of prenatal maternal stressful life events and newborn DNA methylation

Prenatal stress, epigenetically-assessed glucocorticoid exposure at birth, and child psychiatric symptoms: A prospective, multi-cohort study

BACKGROUND

Recent work suggests that DNA methylation can be used as a proxy of fetal glucocorticoid exposure (MPS-GC), showing associations with maternal psychopathology during pregnancy. However, it is unknown whether the MPS-GC may act as a marker for broader prenatal stress and whether it partially mediates associations of prenatal stress with child internalizing and externalizing symptoms.

METHODS

Using harmonized data from three prospective birth cohorts (Npooled = 6086), we examined whether a cumulative measure of prenatal stress, and its individual stress domains, associate with the MPS-GC in cord blood at birth. Next, we examined (i) whether the MPS-GC at birth associates with child psychiatric symptoms, (ii) whether this association is moderated by postnatal stress, and (iii) whether the effect of prenatal stress on child psychiatric symptoms is partially mediated by the MPS-GC at birth.

RESULTS

Our meta-analysis revealed no significant associations between the MPS-GC at birth and prenatal stress or the individual stress domains. Moreover, the MPS-GC did not significantly associate with later child internalizing or externalizing symptoms, and there were no moderating effects of postnatal stress. Additionally, while prenatal stress significantly associated with child psychiatric symptoms, we found no partial mediation via the MPS-GC at birth.

CONCLUSIONS

We did not find support that the MPS-GC in cord blood reliably proxies prenatal stress, associates with child psychiatric risk, or partially mediates the associations between prenatal stress and psychiatric risk.

Associations between maternal adversity and health and children's telomere length

Maternal adversity (e.g., adverse childhood experiences, ACEs) and health (e.g., depressive symptoms and chronic illness) negatively impact offspring's health. One possible mechanism is via premature/accelerated biological aging, as indicated in telomere length. In this 3-year longitudinal study, we examined the association between maternal adversity and health and children's buccal telomere length (bTL) at age 3. Data from 122 mother-child dyads were analyzed. Maternal history of ACEs and chronic illness were collected at baseline (during 20-24 weeks of gestation). Their depressive symptoms across three periods (during pregnancy, 4 weeks after childbirth, and 3 years after childbirth) were also collected. Children's TL were extracted from their buccal swab samples at age 3. The children's bTL was quantified using the quantitative PCR method and expressed in T/S ratio (the ratio of telomere repeats copy numbers to single-copy gene numbers). Results showed pregnant women experienced distinctive trajectories of depressive symptoms over time. Children of mothers with relapsing/remitting depressive symptoms had shorter bTL (β = -0.19, 95% CI = -0.14 to -0.005) than mothers who had low-stable symptoms. This finding remained significant even after accounting for maternal ACEs and chronic illness. Additionally, maternal ACEs, together with depressive symptoms, may affect children's bTL. This study provides relatively comprehensive evidence on the effects of maternal stressors, highlighting the relevance of maternal adversity and depressive symptom patterns as predictors of offspring telomere biology.

Improving Cardiovascular Health Through the Consideration of Social Factors in Genetics and Genomics Research: A Scientific Statement From the American Heart Association

Cardiovascular health (CVH) is affected by genetic, social, and genomic factors across the life course, yet little research has focused on the interrelationships among them. An extensive body of work has documented the impact of social determinants of health at both the structural and individual levels on CVH, highlighting pathways in which racism, housing, violence, and neighborhood environments adversely affect CVH and contribute to disparities in cardiovascular disease. Genetic factors have also been identified as contributors to risk for cardiovascular disease. Emerging evidence suggests that social factors can interact with genetic susceptibility to affect disease risk. Increasingly, social factors have been shown to affect epigenetic markers such as DNA methylation, which can regulate gene and protein expression. This is a potential biological mechanism through which exposure to poor social determinants of health becomes physically embodied at the molecular level, potentially contributing to the development of suboptimal CVH and chronic disease, thus reinforcing and propagating health disparities. The objective of this statement is to highlight and summarize key literature that has examined the joint associations between social, genetic, and genomic factors and CVH and cardiovascular disease.

Epigenetic signatures of intergenerational exposure to violence in three generations of Syrian refugees

Maternal trauma influences infant and adult health outcomes and may impact future generations through epigenetic modifications such as DNA methylation (DNAm). Research in humans on the intergenerational epigenetic transmission of trauma effects is limited. In this study, we assessed DNAm signatures of war-related violence by comparing germline, prenatal, and direct exposures to violence across three generations of Syrian refugees. We compared families in which a pregnant grandmother versus a pregnant mother was exposed to violence and included a control group with no exposure to war. We collected buccal swab samples and survey data from mothers and 1-2 children in each of 48 families (n = 131 participants). Based on an epigenome-wide association study (EWAS), we identified differentially methylated regions (DMPs): 14 were associated with germline and 21 with direct exposure to violence. Most DMPs showed the same directionality in DNAm change across germline, prenatal, and direct exposures, suggesting a common epigenetic response to violence. Additionally, we identified epigenetic age acceleration in association with prenatal exposure to violence in children, highlighting the critical period of in utero development. This is the first report of an intergenerational epigenetic signature of violence, which has important implications for understanding the inheritance of trauma.

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.

DNA methylation as a possible mechanism linking childhood adversity and health: results from a 2-sample mendelian randomization study

Childhood adversity is an important risk factor for adverse health across the life course. Epigenetic modifications, such as DNA methylation (DNAm), are a hypothesized mechanism linking adversity to disease susceptibility. Yet, few studies have determined whether adversity-related DNAm alterations are causally related to future health outcomes or if their developmental timing plays a role in these relationships. Here, we used 2-sample mendelian randomization to obtain stronger causal inferences about the association between adversity-associated DNAm loci across development (ie, birth, childhood, adolescence, and young adulthood) and 24 mental, physical, and behavioral health outcomes. We identified particularly strong associations between adversity-associated DNAm and attention-deficit/hyperactivity disorder, depression, obsessive-compulsive disorder, suicide attempts, asthma, coronary artery disease, and chronic kidney disease. More of these associations were identified for birth and childhood DNAm, whereas adolescent and young adulthood DNAm were more closely linked to mental health. Childhood DNAm loci also had primarily risk-suppressing relationships with health outcomes, suggesting that DNAm might reflect compensatory or buffering mechanisms against childhood adversity rather than acting solely as an indicator of disease risk. Together, our results suggest adversity-related DNAm alterations are linked to both physical and mental health outcomes, with particularly strong impacts of DNAm differences emerging earlier in development.

Mediation of DNA methylation (cg04622888 and cg05037505) in the association between childhood maltreatment and non-suicidal self-injury in early adolescents

It is unclear whether DNA methylation underlies the association between childhood maltreatment (CM) and non-suicidal self-injury (NSSI) in early adolescents. We aim to explore the mediation of specific DNA methylation sites in the associations of CM and its subtypes with NSSI, following investigation on the association between specific DNA methylation sites and NSSI. A case-control study was conducted to examine 155 adolescents aged 12-14 years who were identified to have engaged in NSSI and 201 controls. CM and its subtypes were evaluated by using the Childhood Trauma Questionnaire. The EPIC 850 k Bead Chip was used to discover differential methylation sites (DMSs) in the peripheral blood between 10 NSSI cases and 10 controls. Targeted pyrosequencing was employed to detect the levels of specific DMSs among the total study population, which were selected based on bioinformatics analyses and literature review. We discovered 456 DMSs between NSSI cases and controls, 219 were hypermethylated and 237 were hypomethylated. After controlling for potential confounders, CM or its subtypes, and the methylation of cg04622888 and cg05037505 were all significantly associated with NSSI (all P < 0.05). The total association of CM and its subtypes with NSSI were all significantly (all P < 0.05), with the standardized coefficient (β) ranged from 0.12 for physical neglect to 0.24 for emotional neglect and CM. Significant indirect association of physical neglect with NSSI through methylation of cg04622888 was observed and the mediating proportion was 0.14 (95%CI 0.06-0.23). Significant indirect associations of emotional abuse, emotional neglect, and physical neglect with NSSI through methylation of cg05037505 were also observed, and the mediating proportions were 0.09 (95%CI 0.04-0.14), 0.08 (95%CI, 0.03-0.14) and 0.19 (95%CI 0.07-0.32), respectively. Data of this study suggested that methylation of cg04622888 and cg05037505 were independently associated with NSSI among early adolescents, and they partially mediated the associations of emotional abuse, emotional neglect, and physical abuse with NSSI.

Association between maternal perinatal stress and depression and infant DNA methylation in the first year of life

Maternal stress and depression during pregnancy and the first year of the infant's life affect a large percentage of mothers. Maternal stress and depression have been associated with adverse fetal and childhood outcomes as well as differential child DNA methylation (DNAm). However, the biological mechanisms connecting maternal stress and depression to poor health outcomes in children are still largely unknown. Here we aim to determine whether prenatal stress and depression are associated with differences in cord blood mononuclear cell DNAm (CBMC-DNAm) in newborns (n = 119) and whether postnatal stress and depression are associated with differences in peripheral blood mononuclear cell DNAm (PBMC-DNAm) in children of 12 months of age (n = 113) from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort. Stress was measured using the 10-item Perceived Stress Scale (PSS) and depression was measured using the 20-item Center for Epidemiologic Studies Depression Questionnaire (CESD). Both stress and depression were measured longitudinally at 18 weeks and 36 weeks of pregnancy and six months and 12 months postpartum. We conducted epigenome-wide association studies (EWAS) using robust linear regression followed by a sensitivity analysis in which we bias-adjusted for inflation and unmeasured confounding using the bacon and cate methods. To quantify the cumulative effect of maternal stress and depression, we created composite prenatal and postnatal adversity scores. We identified a significant association between prenatal stress and differential CBMC-DNAm at 8 CpG sites and between prenatal depression and differential CBMC-DNAm at 2 CpG sites. Additionally, we identified a significant association between postnatal stress and differential PBMC-DNAm at 8 CpG sites and between postnatal depression and differential PBMC-DNAm at 11 CpG sites. Using our composite scores, we further identified 2 CpG sites significantly associated with prenatal adversity and 7 CpG sites significantly associated with postnatal adversity. Several of the associated genes, including PLAGL1, HYMAI, BRD2, and ERC2 have been implicated in adverse fetal outcomes and neuropsychiatric disorders. These data further support the finding that differential DNAm may play a role in the relationship between maternal mental health and child health.

Immunophenotypes in psychosis: is it a premature inflamm-aging disorder?

Immunopsychiatric field has rapidly accumulated evidence demonstrating the involvement of both innate and adaptive immune components in psychotic disorders such as schizophrenia. Nevertheless, researchers are facing dilemmas of discrepant findings of immunophenotypes both outside and inside the brains of psychotic patients, as discovered by recent meta-analyses. These discrepancies make interpretations and interrogations on their roles in psychosis remain vague and even controversial, regarding whether certain immune cells are more activated or less so, and whether they are causal or consequential, or beneficial or harmful for psychosis. Addressing these issues for psychosis is not at all trivial, as immune cells either outside or inside the brain are an enormously heterogeneous and plastic cell population, falling into a vast range of lineages and subgroups, and functioning differently and malleably in context-dependent manners. This review aims to overview the currently known immunophenotypes of patients with psychosis, and provocatively suggest the premature immune "burnout" or inflamm-aging initiated since organ development as a potential primary mechanism behind these immunophenotypes and the pathogenesis of psychotic disorders.

Trauma, adversity, and biological aging: behavioral mechanisms relevant to treatment and theory

Although stress and adversity are largely universal experiences, people exposed to greater hardship are at increased risk for negative health consequences. Recent studies identify accelerated biological aging as a mechanism that could explain how trauma and adversity gives rise to poor health, and advances in this area of study coincide with technological innovations in the measurement of biological aging, particularly epigenetic profiles consistent with accelerated aging derived from DNA methylation. In this review, we provide an overview of the current literature examining how adversity might accelerate biological aging, with a specific focus on social and health behaviors. The most extensive evidence in this area suggests that health-compromising behaviors, particularly smoking, may partially explain the association between adversity and accelerated aging. Although there is relatively less published support for the role of social behaviors, emerging evidence points to the importance of social connection as a mechanism for future study. Our review highlights the need to determine the extent to which the associations from adversity to accelerated aging are consistent with causal processes. As we consider these questions, the review emphasizes methodological approaches from the causal inference literature that can help deepen our understanding of how stress and trauma might result in poor health. The use of these methodologies will help provide evidence as to which behavioral interventions might slow aging and improve health, particularly among populations that more often experience adversity and trauma.

Current perspectives on perinatal mental health and neurobehavioral development: focus on regulation, coregulation and self-regulation

PURPOSE OF REVIEW

Perinatal mental health research provides an important perspective on neurobehavioral development. Here, we aim to review the association of maternal perinatal health with offspring neurodevelopment, providing an update on (self-)regulation problems, hypothesized mechanistic pathways, progress and challenges, and implications for mental health.

RECENT FINDINGS

(1) Meta-analyses confirm that maternal perinatal mental distress is associated with (self-)regulation problems which constitute cognitive, behavioral, and affective social-emotional problems, while exposure to positive parental mental health has a positive impact. However, effect sizes are small. (2) Hypothesized mechanistic pathways underlying this association are complex. Interactive and compensatory mechanisms across developmental time are neglected topics. (3) Progress has been made in multiexposure studies. However, challenges remain and these are shared by clinical, translational and public health sciences. (4) From a mental healthcare perspective, a multidisciplinary and system level approach employing developmentally-sensitive measures and timely treatment of (self-)regulation and coregulation problems in a dyadic caregiver-child and family level approach seems needed. The existing evidence-base is sparse.

SUMMARY

During the perinatal period, addressing vulnerable contexts and building resilient systems may promote neurobehavioral development. A pluralistic approach to research, taking a multidisciplinary approach to theoretical models and empirical investigation needs to be fostered.

Association between Maternal Perinatal Stress and Depression on Infant DNA Methylation in the First Year of Life

Maternal stress and depression during pregnancy and the first year of the infant's life affect a large percentage of mothers. Maternal stress and depression have been associated with adverse fetal and childhood outcomes as well as differential child DNA methylation (DNAm). However, the biological mechanisms connecting maternal stress and depression to poor health outcomes in children are still largely unknown. Here we aim to determine whether prenatal stress and depression are associated with changes in cord blood mononuclear cell DNAm (CBMC-DNAm) in newborns (n = 119) and whether postnatal stress and depression are associated with changes in peripheral blood mononuclear cell DNAm (PBMC-DNAm) in children of 12 months of age (n = 113) from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort. Stress was measured using the 10-item Perceived Stress Scale (PSS) and depression was measured using the Center for Epidemiologic Studies Depression Questionnaire (CESD). Both stress and depression were measured at 18 weeks and 36 weeks of pregnancy and six months and 12 months postpartum. We conducted epigenome-wide association studies (EWAS) using robust linear regression followed by a sensitivity analysis in which we bias-adjusted for inflation and unmeasured confounding using the bacon and cate methods. To investigate the cumulative effect of maternal stress and depression, we created composite prenatal and postnatal adversity scores. We identified a significant association between prenatal stress and differential CBMC-DNAm at 8 CpG sites and between prenatal depression and differential CBMC-DNAm at 2 CpG sites. Additionally, we identified a significant association between postnatal stress and differential PBMC-DNAm at 8 CpG sites and between postnatal depression and differential PBMC-DNAm at 11 CpG sites. Using our composite scores, we further identified 2 CpG sites significantly associated with prenatal adversity and 7 CpG sites significantly associated with postnatal adversity. Several of the associated genes, including PLAGL1, HYMAI, BRD2, and ERC2 have been implicated in adverse fetal outcomes and neuropsychiatric disorders. This suggested that differential DNAm may play a role in the relationship between maternal mental health and child health.

Maternal adverse childhood experiences (ACEs) and DNA methylation of newborns in cord blood

BACKGROUND

Adverse childhood experiences (ACEs) increase the risk of poor health outcomes later in life. Psychosocial stressors may also have intergenerational health effects by which parental ACEs are associated with mental and physical health of children. Epigenetic programming may be one mechanism linking parental ACEs to child health. This study aimed to investigate epigenome-wide associations of maternal preconception ACEs with DNA methylation patterns of children. In the Center for the Health Assessment of Mothers and Children of Salinas study, cord blood DNA methylation was measured using the Illumina HumanMethylation450 BeadChip. Preconception ACEs, which occurred during the mothers' childhoods, were collected using a standard ACE questionnaire including 10 ACE indicators. Maternal ACE exposures were defined in this study as (1) the total number of ACEs; (2) the total number of ACEs categorized as 0, 1-3, and > 4; and (3) individual ACEs. Associations of ACE exposures with differential methylated positions, regions, and CpG modules determined using weighted gene co-expression network analysis were evaluated adjusting for covariates.

RESULTS

Data on maternal ACEs and cord blood DNA methylation were available for 196 mother/newborn pairs. One differential methylated position was associated with maternal experience of emotional abuse (cg05486260/FAM135B gene; q value < 0.05). Five differential methylated regions were significantly associated with the total number of ACEs, and 36 unique differential methylated regions were associated with individual ACEs (Šidák p value < 0.05). Fifteen CpG modules were significantly correlated with the total number of ACEs or individual ACEs, of which 8 remained significant in fully adjusted models (p value < 0.05). Significant modules were enriched for pathways related to neurological and immune development and function.

CONCLUSIONS

Maternal ACEs prior to conception were associated with cord blood DNA methylation of offspring at birth. Although there was limited overlap between differential methylated regions and CpGs in modules associated with ACE exposures, statistically significant regions and networks were related to genes involved in neurological and immune function. Findings may provide insights to pathways linking psychosocial stressors to health. Further research is needed to understand the relationship between changes in DNA methylation and child health.