DNA methylation signatures triggered by prenatal maternal stress exposure to a natural disaster: Project Ice Storm

On the role of epigenetic modifications of HPA axis in posttraumatic stress disorder and resilience

Stress is a fundamental adaptive response that invokes amygdala and hypothalamus-pituitary-adrenal (HPA) axis along with other brain regions. Extreme or chronic stress, however, can result in a multitude of neuropsychiatric disorders, including anxiety, paranoia, bipolar disorder (BP), major depressive disorder (MDD), and posttraumatic stress disorder (PTSD). Despite widespread exposure to trauma (70.4%), the incidence of PTSD is relatively low (6.8%), suggesting that either individual susceptibility or adaptability driven by epigenetic and genetic mechanisms are likely at play. PTSD takes hold from exposure to traumatic events, such as death threats or severe abuse, with its severity being impacted by the magnitude of trauma, its frequency, and the nature. This comprehensive review examines how traumatic experiences and epigenetic modifications in hypothalamic-pituitary axis (HPA), such as DNA methylation, histone modifications, noncoding RNAs, and chromatin remodeling, are transmitted across generations, and impact genes such as FKBP prolyl isomerase 5 (FKBP5), nuclear receptor subfamily 3 group C member 1 (NR3C1), brain-derived neurotrophic factor (BDNF), and solute carrier family 6 member 4 (SLC6A4). It also provides a comprehensive overview on trauma reversal, resilience mechanisms, and pro-resilience factors such as histone acetyltransferases (HATs)/histone deacetylases (HDACs) ratio, dehydroepiandrosterone (DHEA)/cortisol ratio, testosterone levels, and neuropeptide Y, thus highlighting potential therapeutic approaches for trauma-related disorders. The studies highlighted here underscore the narrative, for the first time, that the examination and treatment of PTSD and other depressive disorders must invoke a multitude of approaches to seek out the most effective and personalized strategies. We also hope that the discussion emanating from this review will also inform government policies directed toward intergenerational trauma and PTSD.

The association between perinatal depressive symptoms and child neurodevelopment

BACKGROUND

Perinatal depression has been suggested to adversely impact child neurodevelopment. However, the complexity of the early childhood environment challenges conclusive findings.

OBJECTIVE

To evaluate whether there is an association between perinatal depressive symptoms and child intelligence quotient (IQ) at 5 years of age.

STUDY DESIGN

Secondary analysis of an ancillary study to a multicenter randomized trial of thyroxine therapy for pregnant individuals with subclinical hypothyroidism. Dyads of infants and birthing parent, with completed Center for Epidemiological Studies-Depression (CES-D) screens during pregnancy and postpartum and child neurodevelopment testing completed at five years of age (n=209) were included. CES-D screening was performed at 11-20 weeks, 34-38 weeks, and one-year postpartum. Depressive symptoms were categorized as antenatal (i.e., a positive screen at any point during pregnancy) or postpartum. The primary outcome was child IQ score < 85 at 5 years of age using the Wechsler Preschool and Primary Scale of Intelligence III (WPPSI-III) Full Scale test. Secondary outcomes included other assessments of childhood neurodevelopment. Bivariable analyses and multivariable logistic regressions were utilized.

RESULTS

Of the 209 birthing people included, 72 (34%) screened positive for depression during pregnancy and 32 (15%) screened positive one year postpartum. Children born to individuals with a positive antenatal depression screen had a higher odds of IQ < 85 at 5 years of age compared with children born to individuals with a CES-D < 16 (35% vs. 18%, OR 2.4, 95% CI 1.2-4.7). Similar findings were seen for children born to individuals with a positive postpartum depression screen (47% vs. 21%, OR 3.3, 95% CI 1.5-7.3). These associations did not persist in multivariable analyses that controlled for social determinants of health and clinical characteristics (adjusted odd ratio [aOR] 1.4, 95% CI 0.7-3.1; aOR 2.1, 95% CI 0.9-5.1, for antenatal and postpartum depressive symptoms, respectively). Similar findings were observed for other adverse neurodevelopmental outcomes.

CONCLUSIONS

Having a positive perinatal depression screen was not associated with child cognitive outcomes after controlling for covariates including social determinants of health.

Characterising developmental dynamics of adult epigenetic clock sites

BACKGROUND

DNA methylation (DNAm), an epigenetic mechanism that regulates gene activity in response to genetic and environmental influences, changes as we age. DNAm at specific sites on the genome can be used to calculate 'epigenetic clocks', which are powerful biomarkers of age, as well as of ageing. However, little is known about how these clock sites 'behave' during development and what factors influence their variability in early life. This knowledge could be used to optimise healthy ageing well before the onset of age-related conditions.

METHODS

We leveraged results from two longitudinal population-based cohorts (N = 5019 samples from 2348 individuals) to characterise trajectories of adult clock sites from birth to early adulthood. To explore what factors may drive early individual differences at these clock sites, we also tested for enrichment of genetic factors and prenatal exposures based on existing epigenome-wide association meta-analyses.

FINDINGS

We find that clock sites (i) diverge widely in their developmental trajectories, often showing non-linear change over time; (ii) are substantially more likely than non-clock sites to vary between individuals already from birth, differences that are predictive of DNAm variation at later ages; and (iii) show enrichment for genetic influences and prenatal environmental exposures, including prenatal smoking, diet and maternal physical health conditions.

INTERPRETATION

These results suggests that age(ing)-related epigenetic processes might originate-and differ between individuals-already very early in development. Understanding what drives these differences may in future help us to devise better strategies to promote healthy ageing.

FUNDING

This research was conducted while C.A.M.C. was a Hevolution/AFAR New Investigator Awardee in Aging Biology and Geroscience Research. Full personal funding details, as well as cohort funding details, can be found in the Acknowledgements.

Microbiota-immune-brain interactions: A new vision in the understanding of periodontal health and disease

This review highlights the significance of interactions between the microbiota, immune system, nervous and hormonal systems, and the brain on periodontal health and disease. Microorganisms in the microbiota, immune cells, and neurons communicate via homeostatic nervous and hormonal systems, regulating vital body functions. By modulating pro-inflammatory and anti-inflammatory adaptive immune responses, these systems control the composition and number of microorganisms in the microbiota. The strength of these brain-controlled responses is genetically determined but is sensitive to early childhood stressors, which can permanently alter their responsiveness via epigenetic mechanisms, and to adult stressors, causing temporary changes. Clinical evidence and research with humans and animal models indicate that factors linked to severe periodontitis enhance the responsiveness of these homeostatic systems, leading to persistent hyperactivation. This weakens the immune defense against invasive symbiotic microorganisms (pathobionts) while strengthening the defense against non-invasive symbionts at the gingival margin. The result is an increased gingival tissue load of pathobionts, including Gram-negative bacteria, followed by an excessive innate immune response, which prevents infection but simultaneously destroys gingival and periodontal tissues. Thus, the balance between pro-inflammatory and anti-inflammatory adaptive immunity is crucial in controlling the microbiota, and the responsiveness of brain-controlled homeostatic systems determines periodontal health.

Stress and Its Consequences-Biological Strain

Understanding the role of stress in pregnancy and its consequences is important, particularly given documented associations between maternal stress and preterm birth and other pathological outcomes. Physical and psychological stressors can elicit the same biological responses, known as biological strain. Chronic stressors, like poverty and racism (race-based discriminatory treatment), may create a legacy or trajectory of biological strain that no amount of coping can relieve in the absence of larger-scale socio-behavioral or societal changes. An integrative approach that takes into consideration simultaneously social and biological determinants of stress may provide the best insights into the risk of preterm birth. The most successful computational approaches and the most predictive machine-learning models are likely to be those that combine information about the stressors and the biological strain (for example, as measured by different omics) experienced during pregnancy.

What makes clocks tick? Characterizing developmental dynamics of adult epigenetic clock sites

DNA methylation (DNAm) at specific sites can be used to calculate 'epigenetic clocks', which in adulthood are used as indicators of age(ing). However, little is known about how these clock sites 'behave' during development and what factors influence their variability in early life. This knowledge could be used to optimize healthy aging well before the onset of age-related conditions. Here, we leveraged results from two longitudinal population-based cohorts (N=5,019 samples from 2,348 individuals) to characterize trajectories of adult clock sites from birth to early adulthood. We find that clock sites (i) diverge widely in their developmental trajectories, often showing non-linear change over time; (ii) are substantially more likely than non-clock sites to vary between individuals already from birth, differences that are predictive of DNAm variation at later ages; and (iii) show enrichment for genetic and prenatal environmental exposures, supporting an early-origins perspective to epigenetic aging.

DNA methylation-environment interactions in the human genome

Previously, we showed that a massively parallel reporter assay, mSTARR-seq, could be used to simultaneously test for both enhancer-like activity and DNA methylation-dependent enhancer activity for millions of loci in a single experiment (Lea et al., 2018). Here, we apply mSTARR-seq to query nearly the entire human genome, including almost all CpG sites profiled either on the commonly used Illumina Infinium MethylationEPIC array or via reduced representation bisulfite sequencing. We show that fragments containing these sites are enriched for regulatory capacity, and that methylation-dependent regulatory activity is in turn sensitive to the cellular environment. In particular, regulatory responses to interferon alpha (IFNA) stimulation are strongly attenuated by methyl marks, indicating widespread DNA methylation-environment interactions. In agreement, methylation-dependent responses to IFNA identified via mSTARR-seq predict methylation-dependent transcriptional responses to challenge with influenza virus in human macrophages. Our observations support the idea that pre-existing DNA methylation patterns can influence the response to subsequent environmental exposures-one of the tenets of biological embedding. However, we also find that, on average, sites previously associated with early life adversity are not more likely to functionally influence gene regulation than expected by chance.

Mechanisms of Epigenetic Inheritance in Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that causes debilitating functional impairment in patients. Observations from survivors of traumatic historical events solidify that this disease is not only associated with personal experiences but can also be inherited from familial traumas. Over the past decades, researchers have focused on epigenetic inheritance to understand how responses to adverse experiences can be passed down to future generations. This review aims to present recent findings on epigenetic markers related to PTSD and research in the intergenerational inheritance of trauma. By understanding the information, we hope that epigenetic markers can act as biochemical measurements for future clinical practice.

In utero exposure to ionizing radiation and metabolic regulation: perspectives for future multi- and trans-generation effects studies

PURPOSE

The radiation protection community has been particularly attentive to the risks of delayed effects on offspring from low dose or low dose-rate exposures to ionizing radiation. Despite this, the current epidemiologic studies and scientific data are still insufficient to provide the necessary evidence for improving risk assessment guidelines. This literature review aims to inform future studies on multigenerational and transgenerational effects. It primarily focuses on animal studies involving in utero exposure and discusses crucial elements for interpreting the results. These elements include in utero exposure scenarios relative to the developmental stages of the embryo/fetus, and the primary biological mechanisms responsible for transmitting heritable or hereditary effects to future generations. The review addresses several issues within the contexts of both multigenerational and transgenerational effects, with a focus on hereditary perspectives.

CONCLUSIONS

Knowledge consolidation in the field of Developmental Origins of Health and Disease (DOHaD) has led us to propose a new study strategy. This strategy aims to address the transgenerational effects of in utero exposure to low dose and low dose-rate radiation. Within this concept, there is a possibility that disruption of epigenetic programming in embryonic and fetal cells may occur. This disruption could lead to metabolic dysfunction, which in turn may cause abnormal responses to future environmental challenges, consequently increasing disease risk. Lastly, we discuss methodological limitations in our studies. These limitations are related to cohort size, follow-up time, model radiosensitivity, and analytical techniques. We propose scientific and analytical strategies for future research in this field.

Perinatal environmental enrichment changes anxiety-like behaviours in mice and produces similar intergenerational benefits in offspring

Environmental enrichment implemented in early life is able to induce long-term changes in gene expression, synaptic function and behavioural responses. In this study, we evaluated the adult behavioural effects of perinatal environment enrichment in male and female mice (PEE), as well as the males and females of PEE male offspring (OPEE). For this purpose, animals were submitted to the following battery of behavioural analyses: elevated plus maze, open field test, light-dark box and novelty suppression feeding test. The frontal cortex and ventral hippocampus of PEE mice were collected for the evaluation of the expression of gamma-aminobutyric acid (GABA)-related genes. The PEE animals showed an increase in exploratory activity, associated with a reduction in anxiety-like behaviours on the elevated plus maze; this effect was mainly observed in males. Additionally, the male OPEE showed a reduction in anxiety-like behaviours on the elevated plus maze, mainly observed in a reduction of risk assessment-related behaviours. The PEE male mice also showed reduced expression of Gabra3 in the ventral hippocampus when compared to the control group. These results demonstrate that perinatal environmental enrichment promotes a reduction in anxiety-like behaviour that can be transferred intergenerationally.

Placental accelerated aging in antenatal depression

BACKGROUND

Antenatal maternal depression is associated with poor pregnancy outcomes and long-term effects on the offspring. Previous studies have identified links between antenatal depression and placental DNA methylation and between placental epigenetic aging and poor pregnancy outcomes, such as preterm labor and preeclampsia. The relationship between antenatal depression and poor pregnancy outcomes may be partly mediated via placental aging.

OBJECTIVE

This study aimed to investigate whether antenatal depressive symptoms are associated with placental epigenetic age acceleration, an epigenetic aging clock measure derived from the difference between methylation age and gestational age at delivery.

STUDY DESIGN

The study included 301 women who provided placenta samples at delivery as part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies - Singletons that recruited participants from diverse race and ethnic groups at 12 US clinical sites (2009-2013). Women underwent depression screening using the Edinburgh Postnatal Depression Scale up to 6 times across the 3 trimesters of pregnancy. Depressive symptoms status was determined for each pregnancy trimester using an Edinburgh Postnatal Depression Scale score, in which a score of ≥10 was defined as having depressive symptoms and a score of <10 was defined as not having depressive symptoms. Placental DNA methylation was profiled from placenta samples. Placental epigenetic age was estimated using a methylation-based age estimator (placental "epigenetic clock") that has previously been found to have high placental gestational age prediction accuracy for uncomplicated term pregnancies. Placental age acceleration was defined to be the residual upon regressing the estimated epigenetic age on gestational age at delivery. Associations between an Edinburgh Postnatal Depression Scale score of ≥10 and an Edinburgh Postnatal Depression Scale score of <10 in the first, second, and third trimesters of pregnancy (ie, depressive symptoms vs none in each trimester) and placental age acceleration were tested using multivariable linear regression adjusting for maternal age, parity, race and ethnicity, and employment.

RESULTS

There were 31 (10.3%), 48 (16%), and 49 (16.4%) women with depressive symptoms (ie, Edinburgh Postnatal Depression Scale score of ≥10) in the first, second, and third trimesters of pregnancy, respectively. Of these women, 21 (7.2%) had sustained first- and second-trimester depressive symptoms, 19 (7%) had sustained second- and third-trimester depressive symptoms, and 12 (4.8%) had sustained depressive symptoms throughout pregnancy. Women with depressive symptoms in the second trimester of pregnancy had 0.41 weeks higher placental age acceleration than women without depressive symptoms during the second trimester of pregnancy (β=0.21 weeks [95% confidence interval, -0.17 to 0.58; P=.28] during the first trimester of pregnancy; β=0.41 weeks [95% confidence interval, 0.10-0.71; P=.009] during the second trimester of pregnancy; β=0.17 weeks [95% confidence interval, -0.14 to 0.47; P=.29] during the third trimester of pregnancy). Sustained first- and second-trimester depressive symptoms were associated with 0.72 weeks higher placental age acceleration (95% confidence interval, 0.29-1.15; P=.001) than no depressive symptom in the 2 trimesters. The association between second-trimester depressive symptoms and higher placental epigenetic age acceleration strengthened in the analysis of pregnancies with male fetuses (β=0.53 weeks; 95% confidence interval, 0.06-1.08; P=.03) but was not significant in pregnancies with female fetuses.

CONCLUSION

Antenatal depressive symptoms during the second trimester of pregnancy were associated with an average of 0.41 weeks of increased placental age acceleration. Accelerated placental aging may play an important role in the underlying mechanism linking antenatal depression to pregnancy complications related to placental dysfunction.

Legacies of salient environmental experiences-insights from chemosensation

Evidence for parental environments profoundly influencing the physiology, biology, and neurobiology of future generations has been accumulating in the literature. Recent efforts to understand this phenomenon and its underlying mechanisms have sought to use species like rodents and insects to model multi-generational legacies of parental experiences like stress and nutritional exposures. From these studies, we have come to appreciate that parental exposure to salient environmental experiences impacts the cadence of brain development, hormonal responses to stress, and the expression of genes that govern cellular responses to stress in offspring. Recent studies using chemosensory exposure have emerged as a powerful tool to shed new light on how future generations come to be influenced by environments to which parents are exposed. With a specific focus on studies that have leveraged such use of salient chemosensory experiences, this review synthesizes our current understanding of the concept, causes, and consequences of the inheritance of chemosensory legacies by future generations and how this field of inquiry informs the larger picture of how parental experiences can influence offspring biology.

Association Study of a Comprehensive Panel of Neuropeptide-Related Polymorphisms Suggest Potential Roles in Verbal Learning and Memory

Neuropeptides are mostly expressed in regions of the brain responsible for learning and memory and are centrally involved in cognitive pathways. The majority of neuropeptide research has been performed in animal models; with acknowledged differences between species, more research into the role of neuropeptides in humans is necessary to understand their contribution to higher cognitive function. In this study, we investigated the influence of genetic polymorphisms in neuropeptide genes on verbal learning and memory. Variants in genes encoding neuropeptides and neuropeptide receptors were tested for association with learning and memory measures using the Hopkins Verbal Learning Test-Revised (HVLT-R) in a healthy cohort of individuals (n = 597). The HVLT-R is a widely used task for verbal learning and memory assessment and provides five sub-scores: recall, delay, learning, retention, and discrimination. To determine the effect of candidate variants on learning and memory performance, genetic association analyses were performed for each HVLT-R sub-score with over 1300 genetic variants from 124 neuropeptide and neuropeptide receptor genes, genotyped on Illumina OmniExpress BeadChip arrays. This targeted analysis revealed numerous suggestive associations between HVLT-R test scores and neuropeptide and neuropeptide receptor gene variants; candidates include the SCG5, IGFR1, GALR1, OXTR, CCK, and VIPR1 genes. Further characterization of these genes and their variants will improve our understanding of the genetic contribution to learning and memory and provide insight into the importance of the neuropeptide network in humans.

DNA methylation-environment interactions in the human genome

Previously we showed that a massively parallel reporter assay, mSTARR-seq, could be used to simultaneously test for both enhancer-like activity and DNA methylation-dependent enhancer activity for millions of loci in a single experiment (Lea et al., 2018). Here we apply mSTARR-seq to query nearly the entire human genome, including almost all CpG sites profiled either on the commonly used Illumina Infinium MethylationEPIC array or via reduced representation bisulfite sequencing. We show that fragments containing these sites are enriched for regulatory capacity, and that methylation-dependent regulatory activity is in turn sensitive to the cellular environment. In particular, regulatory responses to interferon alpha (IFNA) stimulation are strongly attenuated by methyl marks, indicating widespread DNA methylation-environment interactions. In agreement, methylation-dependent responses to IFNA identified via mSTARR-seq predict methylation-dependent transcriptional responses to challenge with influenza virus in human macrophages. Our observations support the idea that pre-existing DNA methylation patterns can influence the response to subsequent environmental exposures-one of the tenets of biological embedding. However, we also find that, on average, sites previously associated with early life adversity are not more likely to functionally influence gene regulation than expected by chance.

Potential benefits of prenatal diagnosis of TGA in Australia may be outweighed by the adverse effects of earlier delivery: likely causation and potential solutions

OBJECTIVE

Prenatal diagnosis of transposition of great arteries (TGA) is expected to improve postoperative outcomes after neonatal arterial switch operation (ASO); however, published reports give conflicting results. We aimed to determine the association between prenatal diagnosis and early postoperative outcomes after neonatal ASO.

METHODS

Cohort study involving 243 newborns who underwent ASO (70% prenatally diagnosed) between 2010 and 2019. Multivariable regression was used to determine the association between prenatal diagnosis and (a) birth characteristics and (b) postoperative outcomes.

RESULTS

Gestational age and birthweight centile were lower and small-for-gestational-age more common (11.8% vs 1.4%) in those diagnosed prenatally. Among births which followed labour induction or prelabour caesarean, prenatal diagnosis was associated with earlier gestation at birth (mean (SD), 38.5 (1.6) vs 39.2 (1.4), p=0.01). Among births which followed spontaneous labour, prenatal diagnosis was associated with earlier gestation at labour onset (38.2 (1.8) vs 39.2 (1.4), p=0.01). Prenatal diagnosis was associated with longer postoperative mechanical ventilation (incidence rate ratio 1.74, 95% CI 1.37 to 2.21), intensive care (1.70, 1.31 to 2.21) and hospital length of stay (1.37, 1.14 to 1.66) after ASO. Gestational age mediated up to 60% of the effect of prenatal diagnosis on postoperative outcomes.

CONCLUSION

Among newborns undergoing ASO for TGA, prenatal diagnosis is associated with poorer early postoperative outcomes. In addition to minimising iatrogenic factors (such as planned births) resulting in earlier births, evaluation of other dynamics following a prenatal diagnosis which may result in poor fetal growth and earlier onset of spontaneous labour is important.

Perinatal Mental Health Outcomes Following Natural Disasters

This Viewpoint discusses mental health outcomes associated with natural disaster–related stressors during the perinatal period.

Genome-wide neonatal epigenetic changes associated with maternal exposure to the COVID-19 pandemic

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 potential associations between exposure to the COVID-19 pandemic during pregnancy and subsequent changes in the newborn epigenome. While this finding warrants further investigation, it is a point that should be considered in any study assessing newborn DNA methylation studies obtained during this period, even in otherwise healthy pregnancies.

Epigenetics of Trauma Transmission and Fetal Alcohol Spectrum Disorder: What Does the Evidence Support?

Fetal alcohol spectrum disorder (FASD) results from teratogenic impacts of alcohol consumption during pregnancy. Trauma and prenatal alcohol exposure (PAE) can both cause neurodevelopmental impairment, and it has been proposed that FASD can amplify effects of trauma. Certain PAE and trauma effects are mediated via epigenetic mechanisms. The objective of this review is to present the current evidence for epigenetics in trauma transmission as it relates to FASD, to help bridge a potential knowledge gap for social workers and related health professionals. We include a primer on epigenetic mechanisms and inheritance, followed by a summary of the current biomedical evidence supporting intergenerational and transgenerational epigenetic transmission of trauma, its relevance to FASD, the intersection with social transmission, and finally the application to social work. We propose potential models of transmission, considering where social and epigenetic pathways may intersect and/or compound across generations. Overall, we aim to provide a better understanding of epigenetic-trauma transmission for its application to health professions, in particular which beliefs are (and are not) evidence-based. We discuss the lack of research and challenges of studying epigenetic transmission in humans and identify the need for public health interventions and best practices that are based on the current evidence.

Influence of perinatal distress on adverse birth outcomes: A prospective study in the Tigray region, northern Ethiopia

BACKGROUND

In low-income countries, where socioeconomic adversities and perinatal distress are common, adverse birth outcomes are significant public health problems. In these settings, perinatal distress, i.e., high symptoms of anxiety, depression, and/or stress during pregnancy, may be linked with adverse birth outcomes. However, few prospective studies have investigated the impact of perinatal distress on adverse birth outcomes such as preterm birth (gestational age <37 weeks), low birth weight (<2.5 kg), and small for gestational age birth (birth weight below the 10th percentile for gestational age and sex).

OBJECTIVES

Our main objective was to assess the influence of perinatal distress on adverse birth outcomes. Secondly, to investigate if perinatal distress is an independent risk factor or a mediator in the pathway between socioeconomic adversity and adverse birth outcomes.

METHODS

In a prospective cohort study following 991 women from before 20 weeks of gestation until delivery in northern Ethiopia, we collected self-reported data on distress at a mean of 14.8 (standard deviation [SD] = 1.9) and 33.9 (SD = 1.1) weeks of gestation. Distress was measured using the Edinburgh Postnatal Depression Scale, the anxiety subscale of the Hospital Anxiety and Depression Scale, and the Perceived Stress Scale. To determine birth outcomes, gestational age was estimated from the last menstrual period, fundal palpation, and/or ultrasound, while birth weight was obtained from delivery records and measured within three days after birth for those delivered at home. Logistic regression and mediation analysis were employed to evaluate the impact of perinatal distress on adverse birth outcomes.

RESULTS

Perinatal anxiety (OR [95% CI] 1.08 [1.02, 1.13]), depression (1.07 [1.03, 1.11]), stress (1.14 [1.07, 1.22]), and total distress (1.15 [1.07, 1.23]) were all associated with low birth weight, and small for gestational age birth but none did with preterm birth. Mediation analysis demonstrated that perinatal distress was a mediator in the pathway between socioeconomic adversity and adverse birth outcomes.

CONCLUSION

Our study revealed that perinatal distress was linked with adverse birth outcomes and acted as a mediator between socioeconomic adversity and these outcomes. Our findings highlight the importance of screening women for distress and providing appropriate interventions, focusing on women experiencing socioeconomic adversity. Integrating mental health services into primary maternal care in low-income countries could be an effective approach to achieve this.

The Foundations for Chronic Low Back Pain Management may Start in Early Life. Exploring the Role of Caregiver Parental Leave on Future Low Back Pain in the Offspring

Chronic low back pain is difficult to treat and despite increased spending on health services, clinical outcomes for people with low back pain have not improved. Innovative, large scale initiatives seem necessary to stem the cost of low back pain. Psychological health contributes to the development and persistence of chronic low back pain and psychological interventions are important in the management of low back pain. Given the contribution of psychological health to low back pain development and management, it raises the question; can we support psychological health in later life by bolstering emotional development in early life, and reduce the burden of this common condition? Positive early life experiences, including those induced by extended paid parental leave, could bolster emotional development and support the psychological health necessary to manage low back pain in later life. We present the current state of evidence demonstrating the potential value of increasing support for parent-child relationships in early life to reduce the burden of low back pain in future generations. The current evidence is limited to cross-sectional associations, but strong preclinical data clearly shows the potential negative impacts of maternal separation on rodent pup health that compels consideration in human populations. PERSPECTIVE: The benefits stemming from enhanced child development include stable emotional foundations, possibly improving psychological health and low back pain management in the future. This perspective raises questions for future studies - within the context of low back pain, what ingredients bolster stable psychological health? And are these ingredients influenced by parental leave?

linc-mipep and linc-wrb encode micropeptides that regulate chromatin accessibility in vertebrate-specific neural cells

Thousands of long intergenic non-coding RNAs (lincRNAs) are transcribed throughout the vertebrate genome. A subset of lincRNAs enriched in developing brains have recently been found to contain cryptic open-reading frames and are speculated to encode micropeptides. However, systematic identification and functional assessment of these transcripts have been hindered by technical challenges caused by their small size. Here, we show that two putative lincRNAs (linc-mipep, also called lnc-rps25, and linc-wrb) encode micropeptides with homology to the vertebrate-specific chromatin architectural protein, Hmgn1, and demonstrate that they are required for development of vertebrate-specific brain cell types. Specifically, we show that NMDA receptor-mediated pathways are dysregulated in zebrafish lacking these micropeptides and that their loss preferentially alters the gene regulatory networks that establish cerebellar cells and oligodendrocytes - evolutionarily newer cell types that develop postnatally in humans. These findings reveal a key missing link in the evolution of vertebrate brain cell development and illustrate a genetic basis for how some neural cell types are more susceptible to chromatin disruptions, with implications for neurodevelopmental disorders and disease.

Developmental Brain Injury and Social Determinants of Health: Opportunities to Combine Preclinical Models for Mechanistic Insights into Recovery

Epidemiological studies show that social determinants of health are among the strongest factors associated with developmental outcomes after prenatal and perinatal brain injuries, even when controlling for the severity of the initial injury. Elevated socioeconomic status and a higher level of parental education correlate with improved neurologic function after premature birth. Conversely, children experiencing early life adversity have worse outcomes after developmental brain injuries. Animal models have provided vital insight into mechanisms perturbed by developmental brain injuries, which have indicated directions for novel therapeutics or interventions. Animal models have also been used to learn how social environments affect brain maturation through enriched environments and early adverse conditions. We recognize animal models cannot fully recapitulate human social circumstances. However, we posit that mechanistic studies combining models of developmental brain injuries and early life social environments will provide insight into pathways important for recovery. Some studies combining enriched environments with neonatal hypoxic injury models have shown improvements in developmental outcomes, but further studies are needed to understand the mechanisms underlying these improvements. By contrast, there have been more limited studies of the effects of adverse conditions on developmental brain injury extent and recovery. Uncovering the biological underpinnings for early life social experiences has translational relevance, enabling the development of novel strategies to improve outcomes through lifelong treatment. With the emergence of new technologies to analyze subtle molecular and behavioral phenotypes, here we discuss the opportunities for combining animal models of developmental brain injury with social construct models to deconvolute the complex interactions between injury, recovery, and social inequity.

Pregnant in a Pandemic: Mental Wellbeing and Associated Healthy Behaviors Among Pregnant People in California During COVID-19

INTRODUCTION

Pregnancy is a time of increased vulnerability to mental health disorders. Additionally, the COVID-19 pandemic has increased the incidence of depression and anxiety. Thus, we aimed to assess mental health and associated healthy behaviors of pregnant people in California during the pandemic in order to contextualize prenatal well-being during the first pandemic of the twenty-first century.

METHODS

We conducted an online cross-sectional study of 433 pregnant people from June 6 through July 29, 2020. We explored 3 hypotheses: (1) mental health would be worse during the pandemic than in general pregnant samples to date; (2) first-time pregnant people would have worse mental health; and (3) healthy behaviors would be positively related to mental health.

RESULTS

Many of our participants (22%) reported clinically significant depressive symptoms and 31% reported clinically significant anxiety symptoms. Multiparous pregnant people were more likely to express worries about their own health and wellbeing and the process of childbirth than were primiparous pregnant people. Additionally, as pregnancy advanced, sleep and nutrition worsened, while physical activity increased. Lastly, anxious-depressive symptomology was significantly predictive of participant sleep behaviors, nutrition, and physical activity during the past week.

DISCUSSION

Pregnant people had worse mental health during the pandemic, and this was associated with worse health-promoting behaviors. Given that the COVID-19 pandemic and associated risks are likely to persist due to low vaccination rates and the emergence of variants with high infection rates, care that promotes mental and physical well-being for the pregnant population should be a public health priority.

Pre- and peri-natal hurricane exposure alters DNA methylation patterns in children

Hurricane Maria was the worst recorded natural disaster to affect Puerto Rico. Increased stress in pregnant women during and in the aftermath of the hurricane may have induced epigenetic changes in their infants, which could affect gene expression. Stage of gestation at the time of the event was associated with significant differences in DNA methylation in the infants, especially those who were at around 20-25 weeks of gestation when the hurricane struck. Significant differences in DNA methylation were also associated with maternal mental status assessed after the hurricane, and with property damage. Hurricane Maria could have long lasting consequences to children who were exposed to this disaster during pregnancy.

Epigenetics and the role of nutraceuticals in health and disease

In the post-genomic era, the data provided by complete genome sequencing could not answer several fundamental questions about the causes of many noninfectious diseases, diagnostic biomarkers, and novel therapeutic approaches. The rapidly expanding understanding of epigenetic mechanisms, as well as widespread acceptance of their hypothesized role in disease induction, facilitated the development of a number of novel diagnostic markers and therapeutic concepts. Epigenetic aberrations are reversible in nature, which enables the treatment of serious incurable diseases. Therefore, the interest in epigenetic modulatory effects has increased over the last decade, so about 60,000 publications discussing the expression of epigenetics could be detected in the PubMed database. Out of these, 58,442 were published alone in the last 10 years, including 17,672 reviews (69 historical articles), 314 clinical trials, 202 case reports, 197 meta-analyses, 156 letters to the editor, 108 randomized controlled trials, 87 observation studies, 40 book chapters, 22 published lectures, and 2 clinical trial protocols. The remaining publications are either miscellaneous or a mixture of the previously mentioned items. According to the species and gender, the publications included 44,589 human studies (17,106 females, 14,509 males, and the gender is not mentioned in the remaining papers) and 30,253 animal studies. In the present work, the role of epigenetic modulations in health and disease and the influencing factors in epigenetics are discussed.

Sustained social withdrawal behavior and 'difficult' temperament among infants, in relation to maternal affectivity in a low-income area of Kinshasa, Democratic Republic of Congo

Little is known about the relationship between maternal affectivity, social withdrawal and temperament in infants in low-income countries. The goal of the study was to assess the prevalence of social withdrawal behavior in infants aged 8 ± 2.3 months and to explore associations between maternal affectivity during pregnancy and postpartum, infant social withdrawal (as a sign of stress) and 'difficult' temperament as assessed by the mothers. 458 mother-infant dyads were recruited in the city's public mother and child health-care centers. The eight items of the Alarm Distress Baby scale (8-ADBB) and the five-item M (modified) ADBB (M-ADBB) were used to assess sustained withdrawal behavior (ISSWB). The Goldberg Depression and Anxiety Scales were used to assess maternal affectivity and mental well-being. A specially designed questionnaire was used to identify stressful events faced by the mother during pregnancy. The ELDEQ-QCB was used to assess the degree of difficulty in managing the baby. Using the M-ADBB, we found a striking figure of 69.2% for ISSWB with 8-ABB (range 0-29) and 72.7% with the M-ADBB (range 0-10). ISSWB was linked to negative maternal affectivity and to high incidence of stressful events for the mothers, and to the child being viewed as 'difficult' by the mother. Positive prenatal affectivity was a protective factor of ISSWB (OR 0.46). Results are compared with previous studies in Africa. Early screening for ISSWB and identification of factors affecting maternal mental well-being could help in early intervention and increase the chances of better child development.

Inheritance of paternal lifestyles and exposures through sperm DNA methylation

Many different lifestyle factors and chemicals present in the environment are a threat to the reproductive tracts of humans. The potential for parental preconception exposure to alter gametes and for these alterations to be passed on to offspring and negatively affect embryo growth and development is of concern. The connection between maternal exposures and offspring health is a frequent focus in epidemiological studies, but paternal preconception exposures are much less frequently considered and are also very important determinants of offspring health. Several environmental and lifestyle factors in men have been found to alter sperm epigenetics, which can regulate gene expression during early embryonic development. Epigenetic information is thought to be a mechanism that evolved for organisms to pass on information about their lived experiences to offspring. DNA methylation is a well-studied epigenetic regulator that is sensitive to environmental exposures in somatic cells and sperm. The continuous production of sperm from spermatogonial stem cells throughout a man's adult life and the presence of spermatogonial stem cells outside of the blood-testis barrier makes them susceptible to environmental insults. Furthermore, altered sperm DNA methylation patterns can be maintained throughout development and ultimately result in impairments, which could predispose offspring to disease. Innovations in human stem cell-based spermatogenic models can be used to elucidate the paternal origins of health and disease.

Epigenetic Factors Related to Low Back Pain: A Systematic Review of the Current Literature

Low back pain (LBP) is one of the most common causes of pain and disability. At present, treatment and interventions for acute and chronic low back pain often fail to provide sufficient levels of pain relief, and full functional restoration can be challenging. Considering the significant socio-economic burden and risk-to-benefit ratio of medical and surgical intervention in low back pain patients, the identification of reliable biomarkers such as epigenetic factors associated with low back pain could be useful in clinical practice. The aim of this study was to review the available literature regarding the epigenetic factors associated with low back pain. This review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was carried out in October 2022. Only peer-reviewed articles were considered for inclusion. Fourteen studies were included and showed promising results in terms of reliable markers. Epigenetic markers for LBP have the potential to significantly modify disease management. Most recent evidence suggests that epigenetics is a more promising field for the identification of factors associated with LBP, offering a rationale for further investigation in this field with the long-term goal of finding epigenetic biomarkers that could constitute biological targets for disease management and treatment.

DNA methylation as a mediator in the association between prenatal maternal stress and child mental health outcomes: Current state of knowledge

BACKGROUND

Prenatal maternal stress is increasingly recognized as a risk factor for offspring mental health challenges. DNA methylation may be a mechanism, but few studies directly tested mediation. These few integrative studies are reviewed along with studies from three research areas: prenatal maternal stress and child mental health, prenatal maternal stress and child DNA methylation, and child mental health and DNA methylation.

METHODS

We conducted a narrative review of articles in each research area and the few published integrative studies to evaluate the state of knowledge.

RESULTS

Prenatal maternal stress was related to greater offspring internalizing and externalizing symptoms and to greater offspring peripheral DNA methylation of the NR3C1 gene. Youth mental health problems were also related to NR3C1 hypermethylation while epigenome-wide studies identified genes involved in nervous system development. Integrative studies focused on infant outcomes and did not detect significant mediation by DNA methylation though methodological considerations may partially explain these null results.

LIMITATIONS

Operationalization of prenatal maternal stress and child mental health varied greatly. The few published integrative studies did not report conclusive evidence of mediation by DNA methylation.

CONCLUSIONS

DNA methylation likely mediates the association between prenatal maternal stress and child mental health. This conclusion still needs to be tested in a larger number of integrative studies. Key empirical and statistical considerations for future research are discussed. Understanding the consequences of prenatal maternal stress and its pathways of influence will help prevention and intervention efforts and ultimately promote well-being for both mothers and children.

1000 Days: The "WeCare Generation" Program-The Ultimate Model for Improving Human Mental Health and Economics: The Study Protocol

INTRODUCTION

The COVID-19 pandemic stressed the necessity of a new resilience of the human population and health system. The "WeCare Generation" program is a new proposal of territorial intervention, with a new paradigm, on the diseases of the human body and mind.

BACKGROUND

In recent decades, the independent strands of investigation on brain plasticity and early trauma consequences have demonstrated that traumatic experiences in the period from pregnancy to the age of 3 years have an enormous impact on an individual's future development, and both physical and mental health. Research shows that adverse child experiences (ACEs) are associated with a strong risk of conditions such as: harmful alcohol use, smoking, illicit drug use, high body-mass index, depression, anxiety, interpersonal violence, cancer, type 2 diabetes, cardiovascular diseases, stroke respiratory diseases and, as a consequence, to a high financial cost in Italy and also across Europe (1-9% GDP) and the USA (total annual costs estimated to be USD 581 billion in Europe and USD 748 billion in North America). All this suggests that an early intervention on that traumatized-slice of population leads to multiplied savings.

METHODS

A multi-center, randomized, controlled trial was designed. The parents of the future neonatal population (from pregnancy to delivery) with trauma will be enrolled, and randomized to treatment, or control arm. The article describes in detail how the primary outpoint (cost to the national health system), and some secondary outpoints, will be collected.

DISCUSSION

An overall rate of return on investment (ROI) statistically significant 13.0% per annum with an associated benefit/cost ratio (BCR) of 6.3 is expected as the primary outcome of the "WeCare Generation" program. Our proposed model predicts a new medical paradigm aiming to empower new generations, with a strong return on economy and health.

Epigenetic mechanisms underlying the association between maternal climate stress and child growth: characterizing severe drought and its impact on a Kenyan community engaging in a climate change-sensitive livelihood

Pastoralists in East Africa are among the world's most vulnerable communities to climate change, already living near their upper thermal limits and engaging in a climate-sensitive livelihood in a climate change global hot spot. Pregnant women and children are even more at risk. Here, we report the findings of a study characterizing Samburu pastoralist women's experiences of severe drought and outcomes in their children (N = 213, 1.8-9.6 y). First, we examined potential DNA methylation (DNAm) differences between children exposed to severe drought in utero and same-sex unexposed siblings. Next, we performed a high-dimensional mediation analysis to test whether DNAm mediated associations of exposure to severe drought with body weight and adiposity. DNAm was measured using the Infinium MethylationEPIC BeadChip array. After quality control; batch, chip, and genomic inflation corrections; covariate adjustment; and multiple testing correction, 16 CpG sites were differentially methylated between exposed and unexposed children, predominantly in metabolism and immune function pathways. We found a significant indirect effect of drought exposure on child body weight through cg03771070. Our results are the first to identify biological mediators linking severe drought to child growth in a low-income global hot spot for climate change. A better understanding of the mechanisms underlying the association between drought exposure and child growth is important to increasing climate change resilience by identifying targets for intervention.

Prenatal stress from the COVID-19 pandemic predicts maternal postpartum anxiety as moderated by psychological factors: The Australian BITTOC Study

BACKGROUND

While there have been reports of increased perinatal anxiety during the COVID-19 pandemic (Stepowicz et al., 2020), there has been a lack of research on the relative importance of objective hardship and subjective distress. In this study, we explored the extent to which resilience, tolerance of uncertainty, and cognitive appraisal of the pandemic's consequences moderate the effect of prenatal objective hardship and subjective distress due to the pandemic on 2-month postpartum anxiety.

METHODS

Data were collected as part of the Birth in the Time of COVID (BITTOC) study. We measured objective hardship and subjective distress, mental health, and potential psychological moderators in 419 pregnant women residing in Australia, and at two months postpartum. Hierarchical multiple regressions were used.

RESULTS

Objective hardship and subjective distress independently predicted postpartum anxiety. All three psychological factors moderated the effect of objective hardship on anxiety. For women with low/neutral resilience, or low/moderate tolerance of uncertainty, or a negative cognitive appraisal, greater objective hardship predicted higher postpartum anxiety. Conversely, for women with high resilience, or high tolerance of uncertainty, or neutral/positive cognitive appraisal, there was no association. Only a neutral/positive cognitive appraisal significantly buffered the effect of subjective distress on anxiety.

LIMITATIONS

Participants self-selected themselves into the study. The generalizability of our results could be restricted to women of higher socio-economic status.

CONCLUSIONS

These findings help us better understand options for intervention and assessment of vulnerable women during times of stress, along with the mechanisms by which COVID-related stress during pregnancy contributes to postpartum anxiety.

Machine learning-based predictive modeling of resilience to stressors in pregnant women during COVID-19: A prospective cohort study

During the COVID-19 pandemic, pregnant women have been at high risk for psychological distress. Lifestyle factors may be modifiable elements to help reduce and promote resilience to prenatal stress. We used Machine-Learning (ML) algorithms applied to questionnaire data obtained from an international cohort of 804 pregnant women to determine whether physical activity and diet were resilience factors against prenatal stress, and whether stress levels were in turn predictive of sleep classes. A support vector machine accurately classified perceived stress levels in pregnant women based on physical activity behaviours and dietary behaviours. In turn, we classified hours of sleep based on perceived stress levels. This research adds to a developing consensus concerning physical activity and diet, and the association with prenatal stress and sleep in pregnant women. Predictive modeling using ML approaches may be used as a screening tool and to promote positive health behaviours for pregnant women.

DNA methylation patterns and gene expression from amygdala tissue of mature Brahman cows exposed to prenatal stress

Prenatal stress can alter postnatal performance and temperament of cattle. These phenotypic effects may result from changes in gene expression caused by stress-induced epigenetic alterations. Specifically, shifts in gene expression caused by DNA methylation within the brain’s amygdala can result in altered behavior because it regulates fear, stress response and aggression in mammals Thus, the objective of this experiment was to identify DNA methylation and gene expression differences in the amygdala tissue of 5-year-old prenatally stressed (PNS) Brahman cows compared to control cows. Pregnant Brahman cows (n = 48) were transported for 2-h periods at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 days of gestation. A non-transported group (n = 48) were controls (Control). Amygdala tissue was harvested from 6 PNS and 8 Control cows at 5 years of age. Overall methylation of gene body regions, promoter regions, and cytosine-phosphate-guanine (CpG) islands were compared between the two groups. In total, 202 genes, 134 promoter regions, and 133 CpG islands exhibited differential methylation (FDR ≤ 0.15). Following comparison of gene expression in the amygdala between the PNS and Control cows, 2 differentially expressed genes were identified (FDR ≤ 0.15). The minimal differences observed could be the result of natural changes of DNA methylation and gene expression as an animal ages, or because this degree of transportation stress was not severe enough to cause lasting effects on the offspring. A younger age may be a more appropriate time to assess methylation and gene expression differences produced by prenatal stress.

Maternal-fetal stress and DNA methylation signatures in neonatal saliva: an epigenome-wide association study

BACKGROUND

Maternal stress before, during and after pregnancy has profound effects on the development and lifelong function of the infant's neurocognitive development. We hypothesized that the programming of the central nervous system (CNS), hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) induced by prenatal stress (PS) is reflected in electrophysiological and epigenetic biomarkers. In this study, we aimed to find noninvasive epigenetic biomarkers of PS in the newborn salivary DNA.

RESULTS

A total of 728 pregnant women were screened for stress exposure using Cohen Perceived Stress Scale (PSS), 164 women were enrolled, and 114 dyads were analyzed. Prenatal Distress Questionnaire (PDQ) was also administered to assess specific pregnancy worries. Transabdominal fetal electrocardiograms (taECG) were recorded to derive coupling between maternal and fetal heart rates resulting in a 'Fetal Stress Index' (FSI). Upon delivery, we collected maternal hair strands for cortisol measurements and newborn's saliva for epigenetic analyses. DNA was extracted from saliva samples, and DNA methylation was measured using EPIC BeadChip array (850 k CpG sites). Linear regression was used to identify associations between PSS/PDQ/FSI/Cortisol and DNA methylation. We found epigenome-wide significant associations for 5 CpG with PDQ and cortisol at FDR < 5%. Three CpGs were annotated to genes (Illumina Gene annotation file): YAP1, TOMM20 and CSMD1, and two CpGs were located approximately lay at 50 kb from SSBP4 and SCAMP1. In addition, two differentiated methylation regions (DMR) related to maternal stress measures PDQ and cortisol were found: DAXX and ARL4D.

CONCLUSIONS

Genes annotated to these CpGs were found to be involved in secretion and transportation, nuclear signaling, Hippo signaling pathways, apoptosis, intracellular trafficking and neuronal signaling. Moreover, some CpGs are annotated to genes related to autism, post-traumatic stress disorder (PTSD) and schizophrenia. However, our results should be viewed as hypothesis generating until replicated in a larger sample. Early assessment of such noninvasive PS biomarkers will allow timelier detection of babies at risk and a more effective allocation of resources for early intervention programs to improve child development. A biomarker-guided early intervention strategy is the first step in the prevention of future health problems, reducing their personal and societal impact.

Trans- and Multigenerational Maternal Social Isolation Stress Programs the Blood Plasma Metabolome in the F3 Generation

Metabolic risk factors are among the most common causes of noncommunicable diseases, and stress critically contributes to metabolic risk. In particular, social isolation during pregnancy may represent a salient stressor that affects offspring metabolic health, with potentially adverse consequences for future generations. Here, we used proton nuclear magnetic resonance (¹H NMR) spectroscopy to analyze the blood plasma metabolomes of the third filial (F3) generation of rats born to lineages that experienced either transgenerational or multigenerational maternal social isolation stress. We show that maternal social isolation induces distinct and robust metabolic profiles in the blood plasma of adult F3 offspring, which are characterized by critical switches in energy metabolism, such as upregulated formate and creatine phosphate metabolisms and downregulated glucose metabolism. Both trans- and multigenerational stress altered plasma metabolomic profiles in adult offspring when compared to controls. Social isolation stress increasingly affected pathways involved in energy metabolism and protein biosynthesis, particularly in branched-chain amino acid synthesis, the tricarboxylic acid cycle (lactate, citrate), muscle performance (alanine, creatine phosphate), and immunoregulation (serine, threonine). Levels of creatine phosphate, leucine, and isoleucine were associated with changes in anxiety-like behaviours in open field exploration. The findings reveal the metabolic underpinnings of epigenetically heritable diseases and suggest that even remote maternal social stress may become a risk factor for metabolic diseases, such as diabetes, and adverse mental health outcomes. Metabolomic signatures of transgenerational stress may aid in the risk prediction and early diagnosis of non-communicable diseases in precision medicine approaches.

Evaluating the challenges and reproducibility of studies investigating DNA methylation signatures of psychological stress

Psychological stress can increase the risk of a wide range of negative health outcomes. Studies have been completed to determine if DNA methylation changes occur in the human brain because of stress and are associated with long-term effects and disease, but results have been inconsistent. Human candidate gene studies (150) and epigenome-wide association studies (67) were systematically evaluated to assess how DNA methylation is impacted by stress during the prenatal period, early childhood and adulthood. The association between DNA methylation of NR3C1 exon 1F and child maltreatment and early life adversity was well demonstrated, but other genes did not exhibit a clear association. The reproducibility of individual CpG sites in epigenome-wide association studies was also poor. However, biological pathways, including stress response, brain development and immunity, have been consistently identified across different stressors throughout the life span. Future studies would benefit from the increased sample size, longitudinal design, standardized methodology, optimal quality control, and improved statistical procedures.

Association Between Maternal Adverse Childhood Experiences and Neonatal SCG5 DNA Methylation-Effect Modification by Prenatal Home Visiting

Maternal childhood adversity and trauma may elicit biological changes that impact the next generation through epigenetic responses measured in DNA methylation (DNAm). These epigenetic associations could be modified by the early postnatal environment through protective factors, such as early childhood home visiting (HV) programs that aim to mitigate deleterious intergenerational effects of adversity. In a cohort of 53 mother-child pairs recruited in 2015-2016 for the Pregnancy and Infant Development Study (Cincinnati, Ohio), we examined the association between maternal adverse childhood experiences (ACEs) and neonatal DNAm in the secretogranin V gene (SCG5), which is important in neuroendocrine function. We examined prenatal HV as an effect modifier. Mothers completed a questionnaire on ACEs during pregnancy, and infant buccal samples were collected 1 month postpartum. Multivariable linear regression was used to examine the association between maternal ACEs and neonatal DNAm expressed as M-values averaged across 4 cytosine-phosphate-guanine dinucleotide sites. A higher number of maternal ACEs (>3) was associated with a 5.79-percentage-point lower offspring DNAm (95% confidence interval: -10.44, -1.14), and the association was modified by the number of home visits received during pregnancy. In a population of at-risk mother-child dyads, preliminary evidence suggests that maternal ACEs have a relationship with offspring SCG5 DNAm that differs by the amount of prenatal HV.

Programming of Vascular Dysfunction by Maternal Stress: Immune System Implications

A growing body of evidence highlights that several insults during pregnancy impact the vascular function and immune response of the male and female offspring. Overactivation of the immune system negatively influences cardiovascular function and contributes to cardiovascular disease. In this review, we propose that modulation of the immune system is a potential link between prenatal stress and offspring vascular dysfunction. Glucocorticoids are key mediators of stress and modulate the inflammatory response. The potential mechanisms whereby prenatal stress negatively impacts vascular function in the offspring, including poor hypothalamic–pituitary–adrenal axis regulation of inflammatory response, activation of Th17 cells, renin–angiotensin–aldosterone system hyperactivation, reactive oxygen species imbalance, generation of neoantigens and TLR4 activation, are discussed. Alterations in the immune system by maternal stress during pregnancy have broad relevance for vascular dysfunction and immune-mediated diseases, such as cardiovascular disease.

Natural disaster and immunological aging in a nonhuman primate

Weather-related disasters are increasing in frequency and severity, leaving survivors to cope with ensuing mental, financial, and physical hardships. This adversity can exacerbate existing morbidities, trigger new ones, and increase the risk of mortality-features that are also characteristic of advanced age-inviting the hypothesis that extreme weather events may accelerate aging. To test this idea, we examined the impact of Hurricane Maria and its aftermath on immune cell gene expression in large, age-matched, cross-sectional samples from free-ranging rhesus macaques (Macaca mulatta) living on an isolated island. A cross section of macaques was sampled 1 to 4 y before (n = 435) and 1 y after (n = 108) the hurricane. Hurricane Maria was significantly associated with differential expression of 4% of immune-cell-expressed genes, and these effects were correlated with age-associated alterations in gene expression. We further found that individuals exposed to the hurricane had a gene expression profile that was, on average, 1.96 y older than individuals that were not-roughly equivalent to an increase in 7 to 8 y of a human life. Living through an intense hurricane and its aftermath was associated with expression of key immune genes, dysregulated proteostasis networks, and greater expression of inflammatory immune cell-specific marker genes. Together, our findings illuminate potential mechanisms through which the adversity unleashed by extreme weather and potentially other natural disasters might become biologically embedded, accelerate age-related molecular immune phenotypes, and ultimately contribute to earlier onset of disease and death.

Reduction of DNMT3a and RORA in the nucleus accumbens plays a causal role in post-traumatic stress disorder-like behavior: reversal by combinatorial epigenetic therapy

Post-traumatic stress disorder (PTSD) is an incapacitating trauma-related disorder, with no reliable therapy. Although PTSD has been associated with epigenetic alterations in peripheral white blood cells, it is unknown where such changes occur in the brain, and whether they play a causal role in PTSD. Using an animal PTSD model, we show distinct DNA methylation profiles of PTSD susceptibility in the nucleus accumbens (NAc). Data analysis revealed overall hypomethylation of different genomic CG sites in susceptible animals. This was correlated with the reduction in expression levels of the DNA methyltransferase, DNMT3a. Since epigenetic changes in diseases involve different gene pathways, rather than single candidate genes, we next searched for pathways that may be involved in PTSD. Analysis of differentially methylated sites identified enrichment in the RAR activation and LXR/RXR activation pathways that regulate Retinoic Acid Receptor (RAR) Related Orphan Receptor A (RORA) activation. Intra-NAc injection of a lentiviral vector expressing either RORA or DNMT3a reversed PTSD-like behaviors while knockdown of RORA and DNMT3a increased PTSD-like behaviors. To translate our results into a potential pharmacological therapeutic strategy, we tested the effect of systemic treatment with the global methyl donor S-adenosyl methionine (SAM), for supplementing DNA methylation, or retinoic acid, for activating RORA downstream pathways. We found that combined treatment with the methyl donor SAM and retinoic acid reversed PTSD-like behaviors. Thus, our data point to a novel approach to the treatment of PTSD, which is potentially translatable to humans.

Mitochondrial DNA Copy Number Adaptation as a Biological Response Derived from an Earthquake at Intrauterine Stage

An altered mitochondrial DNA copy number (mtDNAcn) at birth can be a marker of increased disease susceptibility later in life. Gestational exposure to acute stress, such as that derived from the earthquake experienced on 19 September 2017 in Mexico City, could be associated with changes in mtDNAcn at birth. Our study used data from the OBESO (Biochemical and Epigenetic Origins of Overweight and Obesity) perinatal cohort in Mexico City. We compared the mtDNAcn in the umbilical cord blood of 22 infants born before the earthquake, 24 infants whose mothers were pregnant at the time of the earthquake (exposed), and 37 who were conceived after the earthquake (post-earthquake). We quantified mtDNAcn by quantitative real-time polymerase chain reaction normalized with a nuclear gene. We used a linear model adjusted by maternal age, body mass index, socioeconomic status, perceived stress, and pregnancy comorbidities. Compared to non-exposed newborns (mean ± SD mtDNAcn: 0.740 ± 0.161), exposed and post-earthquake newborns (mtDNAcn: 0.899 ± 0.156 and 0.995 ± 0.169, respectively) had increased mtDNAcn, p = 0.001. The findings of this study point at mtDNAcn as a potential biological marker of acute stress and suggest that experiencing an earthquake during pregnancy or before gestation can have programing effects in the unborn child. Long-term follow-up of newborns to women who experience stress prenatally, particularly that derived from a natural disaster, is warranted.

Epigenetic signature of chronic low back pain in human T cells

Supplemental Digital Content is Available in the Text.

This study reveals sex-specific DNA methylation signatures in human T cells that discriminate chronic low back pain participants from healthy controls.

Objective:

Determine if chronic low back pain (LBP) is associated with DNA methylation signatures in human T cells that will reveal novel mechanisms and potential therapeutic targets and explore the feasibility of epigenetic diagnostic markers for pain-related pathophysiology.

Methods:

Genome-wide DNA methylation analysis of 850,000 CpG sites in women and men with chronic LBP and pain-free controls was performed. T cells were isolated (discovery cohort, n = 32) and used to identify differentially methylated CpG sites, and gene ontologies and molecular pathways were identified. A polygenic DNA methylation score for LBP was generated in both women and men. Validation was performed in an independent cohort (validation cohort, n = 63) of chronic LBP and healthy controls.

Results:

Analysis with the discovery cohort revealed a total of 2,496 and 419 differentially methylated CpGs in women and men, respectively. In women, most of these sites were hypomethylated and enriched in genes with functions in the extracellular matrix, in the immune system (ie, cytokines), or in epigenetic processes. In men, a unique chronic LBP DNA methylation signature was identified characterized by significant enrichment for genes from the major histocompatibility complex. Sex-specific polygenic DNA methylation scores were generated to estimate the pain status of each individual and confirmed in the validation cohort using pyrosequencing.

Conclusion:

This study reveals sex-specific DNA methylation signatures in human T cells that discriminates chronic LBP participants from healthy controls.

Profiling nonhuman primate germline RNA to understand the legacy of early life stress

Exposure to stress is a risk factor for perturbed mental health, including impoverished regulation of emotional and physiological responses that accompany anxiety and mood disorders, substance abuse and behavioral disorders. Such disruptions to well‐being could be triggered by discrete environmental events or pervasive early life stress (ELS) resulting for example from adverse caregiving. Recent data mostly collected from rodents exposed to anthropogenic stressors suggest that one way via which the detrimental effects of such stress extend beyond the exposed population to future offspring is via stress‐induced alterations of RNA found in the paternal germline. In contrast, less attention has been paid to how naturally occurring stress in males might influence offspring biology and behavior. In this study, we used a translational nonhuman primate model of ELS caused by naturally occurring adverse caregiving of infant macaques to (1) profile total RNA in the adolescent male germline, and (2) identify how those RNA profiles are affected by exposure to ELS. Our findings that the top 100 transcripts identified correspond to transcripts related to germline biology and reproduction demonstrate the validity and feasibility of profiling RNA in the germline of rhesus macaques. While our small sample sizes precluded definitive assessment of stress‐induced alterations of RNA in the male germline of rhesus macaques that experienced ELS, our study sets the foundation for future investigations of how early adversity might alter the male germline, across species and in experimental protocols that involve anthropogenic vs natural stressors.

The top 100 genes in the male germline for which RNA sequences aligned to the sense strand were relevant to male germline‐related biology and reproduction.

Sequences aligned to the antisense strand that may play an important role in regulation of gene expression in the zygote after fertilization were also found.

Naturalistic Stress Hormone Levels Drive Cumulative Epigenomic Changes along the Cellular Lifespan

Environmental stress is ubiquitous in modern societies and can exert a profound and cumulative impact on cell function and health phenotypes. This impact is thought to be in large part mediated by the action of glucocorticoid stress hormones, primarily cortisol in humans. While the underlying molecular mechanisms are unclear, epigenetics-the chemical changes that regulate genomic function without altering the genetic code-has emerged as a key link between environmental exposures and phenotypic outcomes. The present study assessed genome-wide DNA (CpG) methylation, one of the key epigenetic mechanisms, at three timepoints during prolonged (51-day) exposure of cultured human fibroblasts to naturalistic cortisol levels, which can be reached in human tissues during in vivo stress. The findings support a spatiotemporal model of profound and widespread stress hormone-driven methylomic changes that emerge at selected CpG sites, are more likely to spread to nearby located CpGs, and quantitatively accrue at open sea, glucocorticoid receptor binding, and chromatin-accessible sites. Taken together, these findings provide novel insights into how prolonged stress may impact the epigenome, with potentially important implications for stress-related phenotypes.

Hidden pandemic: COVID-19-related stress, SLC6A4 methylation, and infants' temperament at 3 months

The COVID-19 pandemic represents a collective trauma that may have enduring stress effects during sensitive periods, such as pregnancy. Prenatal stress may result in epigenetic signatures of stress-related genes (e.g., the serotonin transporter gene, SLC6A4) that may in turn influence infants' behavioral development. In April 2020, we launched a longitudinal cohort study to assess the behavioral and epigenetic vestiges of COVID-19-related prenatal stress exposure in mothers and infants. COVID-19-related prenatal stress was retrospectively assessed at birth. SLC6A4 methylation was assessed in thirteen CpG sites in mothers and infants' buccal cells. Infants' temperament was assessed at 3-month-age. Complete data were available from 108 mother-infant dyads. Greater COVID-19-related prenatal stress was significantly associated with higher infants' SLC6A4 methylation in seven CpG sites. SLC6A4 methylation at these sites predicted infants' temperament at 3 months.

Perinatal stress and epigenetics

Animal and humans exposed to stress early in life are more likely to suffer from long-term behavioral, mental health, metabolic, immune, and cardiovascular health consequences. The hypothalamus plays a nodal role in programming, controlling, and regulating stress responses throughout the life course. Epigenetic reprogramming in the hippocampus and the hypothalamus play an important role in adapting genome function to experiences and exposures during the perinatal and early life periods and setting up stable phenotypic outcomes. Epigenetic programming during development enables one genome to express multiple cell type identities. The most proximal epigenetic mark to DNA is a covalent modification of the DNA itself by enzymatic addition of methyl moieties. Cell-type-specific DNA methylation profiles are generated during gestational development and define cell and tissue specific phenotypes. Programming of neuronal phenotypes and sex differences in the hypothalamus is achieved by developmentally timed rearrangement of DNA methylation profiles. Similarly, other stations in the life trajectory such as puberty and aging involve predictable and scheduled reorganization of DNA methylation profiles. DNA methylation and other epigenetic marks are critical for maintaining cell-type identity in the brain, across the body, and throughout life. Data that have emerged in the last 15 years suggest that like its role in defining cell-specific phenotype during development, DNA methylation might be involved in defining experiential identities, programming similar genes to perform differently in response to diverse experiential histories. Early life stress impact on lifelong phenotypes is proposed to be mediated by DNA methylation and other epigenetic marks. Epigenetic marks, as opposed to genetic mutations, are reversible by either pharmacological or behavioral strategies and therefore offer the potential for reversing or preventing disease including behavioral and mental health disorders. This chapter discusses data testing the hypothesis that DNA methylation modulations of the HPA axis mediate the impact of early life stress on lifelong behavioral and physical phenotypes.

Epigenetic Changes Induced by Maternal Factors during Fetal Life: Implication for Type 1 Diabetes

Organ-specific autoimmune diseases, such as type 1 diabetes, are believed to result from T-cell-mediated damage of the target tissue. The immune-mediated tissue injury, in turn, is known to depend on complex interactions between genetic and environmental factors. Nevertheless, the mechanisms whereby environmental factors contribute to the pathogenesis of autoimmune diseases remain elusive and represent a major untapped target to develop novel strategies for disease prevention. Given the impact of the early environment on the developing immune system, epigenetic changes induced by maternal factors during fetal life have been linked to a likelihood of developing an autoimmune disease later in life. In humans, DNA methylation is the epigenetic mechanism most extensively investigated. This review provides an overview of the critical role of DNA methylation changes induced by prenatal maternal conditions contributing to the increased risk of immune-mediated diseases on the offspring, with a particular focus on T1D. A deeper understanding of epigenetic alterations induced by environmental stressors during fetal life may be pivotal for developing targeted prevention strategies of type 1 diabetes by modifying the maternal environment.

A bioecocultural approach to supporting adolescent mothers and their young children in conflict-affected contexts

An estimated 12 million girls aged 15-19 years, and 777,000 girls younger than 15 give birth globally each year. Contexts of war and displacement increase the likelihood of early marriage and childbearing. Given the developmentally sensitive periods of early childhood and adolescence, adolescent motherhood in conflict-affected contexts may put a family at risk intergenerationally. We propose that the specifics of normative neuroendocrine development during adolescence, including increased sensitivity to stress, pose additional risks to adolescent girls and their young children in the face of war and displacement, with potential lifelong consequences for health and development. This paper proposes a developmental, dual-generational framework for research and policies to better understand and address the needs of adolescent mothers and their small children. We draw from the literature on developmental stress physiology, adolescent parenthood in contexts of war and displacement internationally, and developmental cultural neurobiology. We also identify culturally meaningful sources of resilience and provide a review of the existing literature on interventions supporting adolescent mothers and their offspring. We aim to honor Edward Zigler's groundbreaking life and career by integrating basic developmental science with applied intervention and policy.