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Nöthling J, Abrahams N, Toikumo S, Suderman M, Mhlongo S, Lombard C, Seedat S, Hemmings SMJ. Genome-wide differentially methylated genes associated with posttraumatic stress disorder and longitudinal change in methylation in rape survivors. Transl Psychiatry 2021; 11:594. [PMID: 34799556 PMCID: PMC8604994 DOI: 10.1038/s41398-021-01608-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 08/01/2021] [Accepted: 09/02/2021] [Indexed: 12/24/2022] Open
Abstract
Rape is associated with a high risk for posttraumatic stress disorder (PTSD). DNA methylation changes may confer risk or protection for PTSD following rape by regulating the expression of genes implicated in pathways affected by PTSD. We aimed to: (1) identify epigenome-wide differences in methylation profiles between rape-exposed women with and without PTSD at 3-months post-rape, in a demographically and ethnically similar group, drawn from a low-income setting; (2) validate and replicate the findings of the epigenome-wide analysis in selected genes (BRSK2 and ADCYAP1); and (3) investigate baseline and longitudinal changes in BRSK2 and ADCYAP1 methylation over six months in relation to change in PTSD symptom scores over 6 months, in the combined discovery/validation and replication samples (n = 96). Rape-exposed women (n = 852) were recruited from rape clinics in the Rape Impact Cohort Evaluation (RICE) umbrella study. Epigenome-wide differentially methylated CpG sites between rape-exposed women with (n = 24) and without (n = 24) PTSD at 3-months post-rape were investigated using the Illumina EPIC BeadChip in a discovery cohort (n = 48). Validation (n = 47) and replication (n = 49) of BRSK2 and ADCYAP1 methylation findings were investigated using EpiTYPER technology. Longitudinal change in BRSK2 and ADCYAP1 was also investigated using EpiTYPER technology in the combined sample (n = 96). In the discovery sample, after adjustment for multiple comparisons, one differentially methylated CpG site (chr10: 61385771/ cg01700569, p = 0.049) and thirty-four differentially methylated regions were associated with PTSD status at 3-months post-rape. Decreased BRSK2 and ADCYAP1 methylation at 3-months and 6-months post-rape were associated with increased PTSD scores at the same time points, but these findings did not remain significant in adjusted models. In conclusion, decreased methylation of BRSK2 may result in abnormal neuronal polarization, synaptic development, vesicle formation, and disrupted neurotransmission in individuals with PTSD. PTSD symptoms may also be mediated by differential methylation of the ADCYAP1 gene which is involved in stress regulation. Replication of these findings is required to determine whether ADCYAP1 and BRSK2 are biomarkers of PTSD and potential therapeutic targets.
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Affiliation(s)
- Jani Nöthling
- Department of Psychiatry, Faculty of Medicine and Health Sciences Stellenbosch University, Cape Town, South Africa.
- Gender and Health Research Unit, South African Medical Research Council, Cape Town, South Africa.
- South African Medical Research Council Unit on the Genomics of Brain Disorders, Stellenbosch University, Cape Town, South Africa.
| | - Naeemah Abrahams
- Gender and Health Research Unit, South African Medical Research Council, Cape Town, South Africa
- Division of Social and Behavioural Sciences, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa
| | - Sylvanus Toikumo
- Department of Psychiatry, Faculty of Medicine and Health Sciences Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council Unit on the Genomics of Brain Disorders, Stellenbosch University, Cape Town, South Africa
| | - Matthew Suderman
- MRC Integrative Epidemiology Unit, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Shibe Mhlongo
- Gender and Health Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - Carl Lombard
- Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa
- Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, Cape Town, South Africa
| | - Soraya Seedat
- Department of Psychiatry, Faculty of Medicine and Health Sciences Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council Unit on the Genomics of Brain Disorders, Stellenbosch University, Cape Town, South Africa
| | - Sian Megan Joanna Hemmings
- Department of Psychiatry, Faculty of Medicine and Health Sciences Stellenbosch University, Cape Town, South Africa
- South African Medical Research Council Unit on the Genomics of Brain Disorders, Stellenbosch University, Cape Town, South Africa
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