Effects of improved on-farm crop storage on DNA methylation of mothers and their infants: evidence from a randomized controlled trial in Kenya.

BACKGROUND: Stress during pregnancy can lead to adverse maternal and infant health outcomes through epigenetic changes in the hypothalamic-pituitary-adrenal axis. Among farmers in low-income countries, one important stressor is food insecurity, which can be reduced using hermetic storage bags. This study aimed to determine, for the first time, whether a hermetic storage bag intervention during pregnancy positively affects maternal and infant DNA methylation of the hypothalamic-pituitary-adrenal axis-related genes FKBP5 and NR3C1. We further analyzed whether anthropometrics, stress, and mental health were associated with DNA methylation. METHODS: This study was part of a larger matched-pair randomized controlled trial focusing on the impact of improved on-farm storage on food security, poverty, and net income of smallholder farming households. A total of N = 149 mothers were recruited by telephone and invited to attend a study appointment at health facilities in Kakamega County, Western Kenya, with their infants in April or May 2021. During the appointment, anthropometric measurements were taken, questionnaires on stress and mental health were administered, and saliva samples were collected. Logistic and multiple linear regression were used to examine the effect of the intervention and related measures on DNA methylation. RESULTS: Mothers in the intervention group showed higher mean NR3C1 methylation levels than those in the control group, corrected for multiple testing. Maternal postpartum body mass index was positively associated with infant NR3C1 CpG3 DNA methylation. The more stressful life events a mother had experienced in the previous 12 months (including during pregnancy), the lower her FKBP5 CpG3 methylation levels. CONCLUSIONS: Food insecurity and stressful life events during pregnancy seem to exert significant effects on maternal DNA methylation. While these stressors did not appear to impact infant DNA methylation in the present study, maternal postpartum body mass index was significantly related to infant methylation. These findings suggest that while infants may be protected from excessive maternal glucocorticoids by placental barrier activity, maternal metabolic status is still reflected in their epigenetic make-up. Trial registration This study was part of a larger matched-pair randomized controlled trial on the impact of improved on-farm crop storage on welfare, nutrition, and human health. Registration can be found in the American Economic Association (AEA) RCT Registry, RCT ID: AEARCTR-0005845.

Early life stress in women with autoimmune thyroid disorders.

Autoimmune thyroid disorders (AITD) represent the most frequent of all autoimmune disorders. Their aetiopathogenesis is incompletely understood, but most likely multifactorial. Early life stress can have long-lasting effects on the immune system. The aim of the present study was to investigate, for the first time, whether patients with AITD are more frequently affected by early life stress. A total of N = 208 women were recruited into a case-control study. Of these, n = 78 (median age: 53, interquartile range: 15) were patients recruited from a thyroid outpatient clinic with confirmed Hashimoto's thyroiditis, Graves' disease, or AITD not otherwise specified. The remaining n = 130 age- and BMI-matched women (median age: 53, interquartile range: 12) were recruited from the general population. Early life stress was measured with the Childhood Trauma Questionnaire. Patients with AITD did not differ from controls regarding sexual abuse, physical abuse, and physical neglect. However, a greater number of patients reported emotional neglect (29.7% vs. 19.5%) and emotional abuse (41.3% vs. 32%). This study provides initial evidence for emotional neglect and abuse as potential risk factors for the development of AITD. Prospective confirmation of these findings could pave the way for the development of interventions to prevent AITD in predisposed individuals.

Methylation of the glucocorticoid receptor promoter in children: Links with parents as teachers, early life stress, and behavior problems.

The present study examined the effect of early life stress (ELS) on the glucocorticoid receptor gene (NR3C1) methylation, the associations between NR3C1 methylation and behavior problems, and the effect of the program Parents as Teachers (PAT) on NR3C1 methylation. Participants included 132 children, 72 assigned to the PAT intervention group and 60 to the PAT control group. Children were aged 3 years, and were living in psychosocially at-risk families. We assessed NR3C1 methylation of the NGFI-A binding regions of exon 1F via sodium bisulfite sequencing from saliva DNA. Results indicated that (a) children living in families receiving PAT had decreased methylation at one single cytosine-guanine dinucleotides (CpG) site; (b) current maternal depressive symptoms and parental disagreement were predictive of increased methylation of mean NGFI-A and three single CpG sites; and (c) increased methylation of mean NGFI-A and one single CpG site was significantly associated with increased internalizing and externalizing symptoms. In addition, mean NGFI-A was a mediator of the association between parental disagreement and a child's affective problems. These results suggest that PAT may contribute to preventing NR3C1 methylation in preschool children living in psychosocially at-risk situations, and confirm previous findings on the associations between ELS, NR3C1 methylation, and behavior problems.

Sleep and Methylation of Estrogen Receptor Genes, ESR1 and GPER, in Healthy Middle-Aged and Older Women: Findings from the Women 40+ Healthy Aging Study.

PURPOSE: Sleep problems in middle-aged and older women are very common and have been associated with menopause-related changes in estrogen levels. However, not all women experience sleep problems as they enter perimenopause, and epigenetic mechanisms might contribute to the differences in sleep quality within this population. In this study, we hypothesized that increased methylation of two estrogen receptor (ER) genes (ESR1 and GPER) would be associated with increased sleep problems in healthy pre-, peri-, and postmenopausal women, either directly or indirectly through the experience of vasomotor symptoms (VMS). MATERIALS AND METHODS: In 130 healthy women aged 40-73 years, we assessed DNA methylation from dried blood spots (DBS). Women rated their sleep quality using the Pittsburgh Sleep Quality Index (PSQI), and VMS using the Menopause Rating Scale (MRS). RESULTS: Higher percentage methylation of ESR1 was associated with increased sleep problems, mediated by VMS, even after controlling for age, menopausal status, body mass index, estradiol levels, depressive symptoms, and caffeine consumption. There was no significant association between GPER methylation and either sleep problems or VMS. CONCLUSION: The study findings support an association between increased ESR1 methylation and sleep problems through increased VMS among healthy women aged 40-73 years.

Differential ESR1 Promoter Methylation in the Peripheral Blood-Findings from the Women 40+ Healthy Aging Study.

Background Estrogen receptor α (ERα) contributes to maintaining biological processes preserving health during aging. DNA methylation changes of ERα gene (ESR1) were established as playing a direct role in the regulation of ERα levels. In this study, we hypothesized decreased DNA methylation of ESR1 associated with postmenopause, lower estradiol (E2) levels, and increased age among healthy middle-aged and older women. Methods We assessed DNA methylation of ESR1 promoter region from dried blood spots (DBSs) and E2 from saliva samples in 130 healthy women aged 40-73 years. Results We found that postmenopause and lower E2 levels were associated with lower DNA methylation of a distal regulatory region, but not with DNA methylation of proximal promoters. Conclusion Our results indicate that decreased methylation of ESR1 cytosine-phosphate-guanine island (CpGI) shore may be associated with conditions of lower E2 in older healthy women.

DNA Methylation in Healthy Older Adults With a History of Childhood Adversity-Findings From the Women 40+ Healthy Aging Study.

Background: Adversity in early development seems to increase the risk of stress-related somatic disorders later in life. Physiologically, functioning of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes is often discussed as long-term mediators of risk. In particular, DNA methylation in the glucocorticoid receptor gene promoter (NR3C1) has been associated with type and strength of early life adversity and subsequent effects on HPA axis signaling in humans. Animal studies, moreover, suggest changes in DNA methylation in the estrogen receptor gene (ERα) upon early life adversity. We investigated the association of type and severity of childhood adversity with methylation in NR3C1 and ERα and additionally considered associations between methylation and steroid hormone secretion. Methods: The percentage of methylation within the NR3C1 promoter and the ERα shore was investigated using dried blood spot samples of 103 healthy women aged 40-73 years. Childhood adversity was examined with the Childhood Trauma Questionnaire. Linear regression analyses were performed with methylation as dependent variable and the experience of emotional abuse and neglect, physical abuse and neglect, and sexual abuse (compared to non-experience) as independent variables. All analyses were controlled for age, BMI, annual household income, and smoking status and were adjusted for multiple testing. Results: Overall, over 70% of the sample reported having experienced any kind of abuse or neglect of at least low intensity. There were no significant associations between childhood adversity and methylation in the NR3C1 promoter (all p > .10). Participants reporting emotional abuse showed significantly higher methylation in the ERα shore than those who did not (p = .001). Additionally, higher levels of adversity were associated with higher levels of ERα shore methylation (p = .001). Conclusion: In healthy women, early life adversity does not seem to result in NR3C1 promoter hypermethylation in midlife and older age. This is the first study in humans to suggest that childhood adversity might, however, epigenetically modify the ERα shore. Further studies are needed to gain a better understanding of why some individuals remain healthy and others develop psychopathologies in the face of childhood adversity.

Polymorphisms in genes related to the hypothalamic-pituitary-adrenal axis and antidepressant response - Systematic review.

OBJECTIVE: Around 50% of depressed patients do not respond to antidepressants. Evidence from familial studies suggests a genetic component to this. This study investigated whether patients with polymorphisms in genes related to the hypothalamic-pituitary-adrenal (HPA) axis were less likely to respond to antidepressants. METHOD: EMBASE, MEDLINE, PsycINFO, and the Cochrane Library were searched. Inclusionary criteria were: 1) patients with depression, 2) study of HPA axis-related candidate genes, 3) at least four weeks of antidepressants, and 4) assessment of depressive symptoms dividing patients into non-responders and responders. RESULTS: Nineteen studies were identified. Non-responders and responders did not differ in single nucleotide polymorphisms (SNPs) in genes encoding arginine vasopressin. Findings were equivocal regarding genes encoding the FK506 binding protein 5 and glucocorticoid and mineralocorticoid receptors. Specific SNPs and haplotypes within genes related to corticotropin-releasing hormone (CRHBP, CRHR1) and melanocortins (POMC) predicted non-responder status. CONCLUSIONS: Replication studies and additional investigations exploring gene x environment and drug x environment interactions are necessary before pharmacological treatments may be adjusted based on a patient's genetic profile.

Combining genetic and epigenetic parameters of the serotonin transporter gene in obsessive-compulsive disorder.

While genetic variants have been reported to be associated with obsessive-compulsive disorder (OCD), the small effect sizes suggest that epigenetic mechanisms such as DNA methylation may also be relevant. The serotonin transporter (SLC6A4) gene has been extensively investigated in relation to OCD, since serotonin reuptake inhibitors are the pharmacological treatment of choice for the disorder. The current study set three questions: Firstly, whether the high expressing loci of the SLC6A4 polymorphisms, 5-HTTLPR + rs25531, rs25532 and rs16965628 are associated with family-based (n = 164 trios) and case-control OCD (n = 186, 152, respectively). This was also examined by a meta-analysis. Secondly, whether DNA methylation and RNA levels of the SLC6A4 differ in saliva and blood of a subset of samples from pediatric and adult OCD patients and matched controls. And lastly, whether morning awakening cortisol levels correlate with the above. A meta-analysis confirmed the association of the LA-allele with OCD (OR = 1.21, p = 0.00018), maintaining significance in the early-onset OCD subgroup (OR = 1.21, p = 0.022). There was no association between rs25532 or rs16965628 and OCD. Our preliminary data showed that SLC6A4 DNA methylation levels in an amplicon located at the beginning of the first intron were significantly higher in the saliva of pediatric OCD patients compared to controls and adult patients with OCD, but no alterations in RNA levels or in polymorphism interactions were observed. Morning awakening salivary cortisol levels positively correlated with methylation levels, and negatively correlated with RNA levels. This study further supports the involvement of the SLC6A4 gene in OCD through both genetic and epigenetic mechanisms. This finding needs to be explored further in an independent large sample.

Medium throughput bisulfite sequencing for accurate detection of 5-methylcytosine and 5-hydroxymethylcytosine.

BACKGROUND: Epigenetic modifications of DNA, such as 5-methylcytosine and 5-hydroxymethycytosine, play important roles in development and disease. Here, we present a cost-effective and versatile methodology for the analysis of DNA methylation in targeted genomic regions, which comprises multiplexed, PCR-based preparation of bisulfite DNA libraries followed by customized MiSeq sequencing. RESULTS: Using bisulfite and oxidative bisulfite conversion of DNA, we have performed multiplexed targeted sequencing to analyse several kilobases of genomic DNA in up to 478 samples, and achieved high coverage data of 5-methylcytosine and 5-hydroxymethycytosine at single-base resolution. Our results demonstrate the ability of this methodology to detect all levels of cytosine modifications at greater than 100× coverage in large sample sets at low cost compared to other targeted methods. CONCLUSIONS: This approach can be applied to multiple settings, from candidate gene to clinical studies, and is especially useful for validation of differentially methylated or hydroxymethylated regions following whole-genome analyses.