Genome-wide differentially methylated genes associated with posttraumatic stress disorder and longitudinal change in methylation in rape survivors

Going Beyond Childhood and Gender-Based Violence: Epigenetic Modifications and Inheritance

Being exposed to childhood or gender-based violence is associated with subsequent adverse events in individual lives. Not only can it cause psychological distress but violence survivors suffer from a range of long-term adverse health outcomes, including higher morbidity, higher mortality, and higher risk of chronic diseases. Epigenetics may be involved in the determinisms of these long-term detrimental effects. A large body of evidence supports this biological mechanism to explain violence-related health impairment in the long term. However, studies specifically focusing on violence are scant and nonunivocal. Epigenetic modifications of genes involved in stress response and in the hypothalamus-pituitary-adrenal axis regulation are the most commonly and consistently reported. Promising evidence also emerged for the use of epigenetic clocks. Finally, although very limited, there is evidence supporting the notion that long-term health impairment may be transmitted from one generation to the other. Overall, despite promising, available evidence is yet incomplete. The overlap with pure psychological mechanisms of health impairment exposes the findings to confounders and hampers strong conclusions. Based on a literature search on PubMed/Embase, our narrative review aims to illustrate the evidence concerning the potential bond between epigenetics and violence, including also possible impacts on later generations. The goal is to encourage further research to help the development of a more holistic approach for such a vulnerable and often neglected population. Further research is warranted to precisely disentangle the role of epigenetics in mediating the long-term health impairment associated with childhood or gender-based violence. Advances in this area may open new avenues of treatment. Epigenetic modifications may indeed be reversible and could be an attractive therapeutic target to minimize the long-term consequences of childhood or gender-based violence.

Genome-wide DNA methylation analysis related to ALS patient progression and survival

BACKGROUND

Epigenetics contributes to the pathogenesis of amyotrophic lateral sclerosis (ALS). We aimed to characterize the DNA methylation profiles associated with clinical heterogeneity in disease progression and survival among patients.

METHODS

We included a cohort of 41 patients with sporadic ALS, with a median follow-up of 86.9 months, and 27 rigorously matched healthy controls. Blood-based genome-wide DNA methylation analysis was conducted.

RESULTS

A total of 948 progression rate-associated differentially methylated positions, 298 progression rate-associated differentially methylated regions (R-DMRs), 590 survival time-associated DMPs, and 197 survival time-associated DMRs (S-DMRs) were identified, using complementary grouping strategies. Enrichment analysis of differentially methylated genes highlighted the involvement of synapses and axons in ALS progression and survival. Clinical analysis revealed a positive correlation between the average methylation levels of the R-DMR in PRDM8 and disease progression rate (r = 0.479, p = 0.002). Conversely, there was an inverse correlation between the average methylation levels of the R-DMR in ANKRD33 and disease progression rate (r = - 0.476, p = 0.002). In addition, patients with higher methylation levels within the S-DMR of ZNF696 experienced longer survival (p = 0.016), while those with elevated methylation levels in the S-DMR of RAI1 had shorter survival (p = 0.006).

CONCLUSION

DNA methylation holds promise as a potential biomarker for tracking disease progression and predicting survival outcome and also offers targets for precision medicine.

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.

Advances in the molecular neurobiology of posttraumatic stress disorder from global contexts: A systematic review of longitudinal studies

Trauma exposure is prevalent globally and is a defining event for the development of posttraumatic stress disorder (PTSD), characterised by intrusive thoughts, avoidance behaviours, hypervigilance and negative alterations in cognition and mood. Exposure to trauma elicits a range of physiological responses which can interact with environmental factors to confer relative risk or resilience for PTSD. This systematic review summarises the findings of longitudinal studies examining biological correlates predictive of PTSD symptomology. Databases (Pubmed, Scopus and Web of Science) were systematically searched using relevant keywords for studies published between 1 January 2021 and 31 December 2022. English language studies were included if they were original research manuscripts or meta-analyses of cohort investigations that assessed longitudinal relationships between one or more molecular-level measures and either PTSD status or symptoms. Eighteen of the 1,042 records identified were included. Studies primarily included military veterans/personnel, individuals admitted to hospitals after acute traumatic injury, and women exposed to interpersonal violence or rape. Genomic, inflammation and endocrine measures were the most commonly assessed molecular markers and highlighted processes related to inflammation, stress responding, and learning and memory. Quality assessments were done using the Systematic Appraisal of Quality in Observational Research, and the majority of studies were rated as being of high quality, with the remainder of moderate quality. Studies were predominantly conducted in upper-income countries. Those performed in low- and middle-income countries were not broadly representative in terms of demographic, trauma type and geographic profiles, with three out of the four studies conducted assessing only female participants, rape exposure and South Africa, respectively. They also did not generate multimodal data or use machine learning or multilevel modelling, potentially reflecting greater resource limitations in LMICs. Research examining molecular contributions to PTSD does not adequately reflect the global burden of the disorder.

Violence against Women and Stress-Related Disorders: Seeking for Associated Epigenetic Signatures, a Pilot Study

BACKGROUND

Violence against women is a relevant health and social problem with negative consequences on women's health. The interaction between genome and environmental factors, such as violence, represents one of the major challenges in molecular medicine. The Epigenetics for WomEn (EpiWE) project is a multidisciplinary pilot study that intends to investigate the epigenetic signatures associated with intimate partner and sexual violence-induced stress-related disorders.

MATERIALS AND METHODS

In 2020, 62 women exposed to violence (13 women suffering from sexual violence and 49 from Intimate Partner Violence, IPV) and 50 women with no history of violence were recruited at the Service for Sexual and Domestic Violence. All women aged 18-65 were monitored for their physical and psychological conditions. Blood samples were collected, and DNAs were extracted and underwent the epigenetic analysis of 10 stress-related genes.

RESULTS

PTSD prevalence in victims was assessed at 8.1%. Quantitative methylation evaluation of the ten selected trauma/stress-related genes revealed the differential iper-methylation of brain-derived neurotrophic factor, dopamine receptor D2 and insulin-like growth factor 2 genes. These genes are among those related to brain plasticity, learning, and memory pathways.

CONCLUSIONS

The association of early detection of posttraumatic distress and epigenetic marker identification could represent a new avenue for addressing women survivors toward resilience. This innovative approach in gender-based violence studies could identify new molecular pathways associated with the long-term effects of violence and implement innovative protocols of precision medicine.

Methylation in MAD1L1 is associated with the severity of suicide attempt and phenotypes of depression

Depression is a multifactorial disorder representing a significant public health burden. Previous studies have linked multiple single nucleotide polymorphisms with depressive phenotypes and suicidal behavior. MAD1L1 is a mitosis metaphase checkpoint protein that has been linked to depression in GWAS. Using a longitudinal EWAS approach in an adolescent cohort at two time points (n = 216 and n = 154), we identified differentially methylated sites that were associated with depression-related genetic variants in MAD1L1. Three methylation loci (cg02825527, cg18302629, and cg19624444) were consistently hypomethylated in the minor allele carriers, being cross-dependent on several SNPs. We further investigated whether DNA methylation at these CpGs is associated with depressive psychiatric phenotypes in independent cohorts. The first site (cg02825527) was hypomethylated in blood (exp(β) = 84.521, p value ~ 0.003) in participants with severe suicide attempts (n = 88). The same locus showed increased methylation in glial cells (exp(β) = 0.041, p value ~ 0.004) in the validation cohort, involving 29 depressed patients and 29 controls, and showed a trend for association with suicide (n = 40, p value ~ 0.089) and trend for association with depression treatment (n = 377, p value ~ 0.075). The second CpG (cg18302629) was significantly hypomethylated in depressed participants (exp(β) = 56.374, p value ~ 0.023) in glial cells, but did not show associations in the discovery cohorts. The last methylation site (cg19624444) was hypomethylated in the whole blood of severe suicide attempters; however, this association was at the borderline for statistical significance (p value ~ 0.061). This locus, however, showed a strong association with depression treatment in the validation cohort (exp(β) = 2.237, p value ~ 0.003) with 377 participants. The direction of associations between psychiatric phenotypes appeared to be different in the whole blood in comparison with brain samples for cg02825527 and cg19624444. The association analysis between methylation at cg18302629 and cg19624444 and MAD1L1 transcript levels in CD¹⁴⁺ cells shows a potential link between methylation at these CpGs and MAD1L1 expression. This study suggests evidence that methylation at MAD1L1 is important for psychiatric health as supported by several independent cohorts.

Adiponectin gene polymorphisms and posttraumatic stress disorder symptoms among female rape survivors: an exploratory study

Background: Rape is a common traumatic event which may result in the development of posttraumatic stress disorder (PTSD), yet few studies have investigated risk biomarkers in sexually traumatised individuals. Adiponectin is a novel cytokine within inflammatory and cardiometabolic pathways with evidence of involvement in PTSD. Objective: This prospective exploratory study in a sample of female rape survivors investigated the association of single nucleotide polymorphisms (SNPs) in the adiponectin gene (ADIPOQ) and posttraumatic stress symptom (PTSS) severity, and the interaction of these SNPs of interest with childhood trauma in modifying the association with PTSS severity. Method: The study involved 455 rape-exposed black South African women (mean age (SD), 25.3 years (±5.5)) recruited within 20 days of being raped. PTSS was assessed using the Davidson Trauma Scale (DTS) and childhood trauma was assessed using a modified version of the Childhood Trauma Scale-Short Form Questionnaire. Eight ADIPOQ SNPs (rs17300539, rs16861194, rs16861205, rs2241766, rs6444174, rs822395, rs1501299, rs1403697) were genotyped using KASP. Mixed linear regression models were used to test additive associations of ADIPOQ SNPs and PTSS severity at baseline, 3 and 6 months following rape. Results: The mean DTS score post-sexual assault was high (71.3 ± 31.5), with a decrease in PTSS severity shown over time for all genotypes. rs6444174TT genotype was inversely associated with baseline PTSS in the unadjusted model (β = -13.6, 95% CI [-25.1; -2.1], p = .021). However, no genotype was shown to be significantly associated with change in PTSS severity over time and therefore ADIPOQ SNP x childhood trauma interaction was not further investigated. Conclusion: None of the ADIPOQ SNPs selected for investigation in this population were shown to be associated with change in PTSS severity over a 6-month period and therefore their clinical utility as risk biomarkers for rape-related PTSD appears limited. These SNPs should be further investigated in possible gene-gene and gene-environment interactions.