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Moodley A, Womersley JS, Swart PC, van den Heuvel LL, Malan-Müller S, Seedat S, Hemmings SMJ. A network analysis investigating the associations between posttraumatic stress symptoms, markers of inflammation and metabolic syndrome. J Psychiatr Res 2023; 165:105-114. [PMID: 37487292 DOI: 10.1016/j.jpsychires.2023.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/22/2023] [Accepted: 07/15/2023] [Indexed: 07/26/2023]
Abstract
Chronic systemic inflammation has been implicated in trauma exposure, independent of a psychiatric diagnosis, and in posttraumatic stress disorder (PTSD) and its highly comorbid conditions, such as metabolic syndrome (MetS). The present study used network analysis to examine the interacting associations between pro-inflammatory cytokines, posttraumatic stress (PTS) symptoms and symptom clusters, and individual components of MetS, in a cohort of 312 participants (n = 139 PTSD cases, n = 173 trauma-exposed controls). Pro-inflammatory cytokines were measured in serum samples using immunoturbidimetric and multiplex assays. Three network models were assessed, and the decision on which model to use was guided by network stability estimates and denseness. Weak negative associations were observed between interleukin one beta (IL-1β) and detachment (D6) and irritability (E1); tumour necrosis factor alpha (TNFα) and hypervigilance (E3); and C-reactive protein (CRP) and emotional cue reactivity (B4), which could be due to high cortisol levels present in a female-majority cohort. Network models also identified positive associations between CRP and waist circumference, blood pressure, and high-density lipoprotein cholesterol (HDL-C). The strongest association was observed between CRP and waist circumference, providing evidence that central obesity is an important inflammatory component of MetS. Some networks displayed high instability, which could be due to the small pool of participants with viable cytokine data. Overall, this study provides evidence for associations between inflammation, PTS symptoms and components of MetS. Future longitudinal studies measuring pro-inflammatory cytokines in the immediate aftermath of trauma are required to gain better insight into the role of inflammation in trauma-exposure and PTSD.
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Affiliation(s)
- Allegra Moodley
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; Department of Biomedical Sciences, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Jacqueline S Womersley
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Patricia C Swart
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Leigh L van den Heuvel
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Stefanie Malan-Müller
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; Department of Pharmacology and Toxicology, Faculty of Medicine, University Complutense Madrid (UCM), Madrid, Spain; Biomedical Network Research Center of Mental Health (CIBERSAM), Institute of Health Carlos III, Madrid, Spain; Neurochemistry Research Institute UCM, Hospital 12 de Octubre Research Institute (Imas12), Madrid, Spain
| | - Soraya Seedat
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa
| | - Sian M J Hemmings
- Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa; South African Medical Research Council/Stellenbosch University Extramural Unit on the Genomics of Brain Disorders, Department of Psychiatry, Stellenbosch University, Tygerberg, Cape Town, South Africa.
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Swart PC, Du Plessis M, Rust C, Womersley JS, van den Heuvel LL, Seedat S, Hemmings SMJ. Identifying genetic loci that are associated with changes in gene expression in PTSD in a South African cohort. J Neurochem 2023; 166:705-719. [PMID: 37522158 PMCID: PMC10953375 DOI: 10.1111/jnc.15919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/30/2023] [Accepted: 07/05/2023] [Indexed: 08/01/2023]
Abstract
The molecular mechanisms underlying posttraumatic stress disorder (PTSD) are yet to be fully elucidated, especially in underrepresented population groups. Expression quantitative trait loci (eQTLs) are DNA sequence variants that influence gene expression, in a local (cis-) or distal (trans-) manner, and subsequently impact cellular, tissue, and system physiology. This study aims to identify genetic loci associated with gene expression changes in a South African PTSD cohort. Genome-wide genotype and RNA-sequencing data were obtained from 32 trauma-exposed controls and 35 PTSD cases of mixed-ancestry, as part of the SHARED ROOTS project. The first approach utilised 108 937 single-nucleotide polymorphisms (SNPs) (MAF > 10%) and 11 312 genes with Matrix eQTL to map potential eQTLs, while controlling for covariates as appropriate. The second analysis was focused on 5638 SNPs related to a previously calculated PTSD polygenic risk score for this cohort. SNP-gene pairs were considered eQTLs if they surpassed Bonferroni correction and had a false discovery rate <0.05. We did not identify eQTLs that significantly influenced gene expression in a PTSD-dependent manner. However, several known cis-eQTLs, independent of PTSD diagnosis, were observed. rs8521 (C > T) was associated with TAGLN and SIDT2 expression, and rs11085906 (C > T) was associated with ZNF333 expression. This exploratory study provides insight into the molecular mechanisms associated with PTSD in a non-European, admixed sample population. This study was limited by the cross-sectional design and insufficient statistical power. Overall, this study should encourage further multi-omics approaches towards investigating PTSD in diverse populations.
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Affiliation(s)
- Patricia C. Swart
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Morne Du Plessis
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Carlien Rust
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Jacqueline S. Womersley
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Leigh L. van den Heuvel
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Soraya Seedat
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
| | - Sian M. J. Hemmings
- Department of Psychiatry, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
- South African Medical Research Council/Stellenbosch University Genomics of Brain Disorders UnitCape TownSouth Africa
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Swart PC, van den Heuvel LL, Lewis CM, Seedat S, Hemmings SMJ. A Genome-Wide Association Study and Polygenic Risk Score Analysis of Posttraumatic Stress Disorder and Metabolic Syndrome in a South African Population. Front Neurosci 2021; 15:677800. [PMID: 34177453 PMCID: PMC8222611 DOI: 10.3389/fnins.2021.677800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/07/2021] [Indexed: 11/13/2022] Open
Abstract
Posttraumatic stress disorder (PTSD) is a trauma-related disorder that frequently co-occurs with metabolic syndrome (MetS). MetS is characterized by obesity, dyslipidemia, and insulin resistance. To provide insight into these co-morbidities, we performed a genome-wide association study (GWAS) meta-analysis to identify genetic variants associated with PTSD, and determined if PTSD polygenic risk scores (PRS) could predict PTSD and MetS in a South African mixed-ancestry sample. The GWAS meta-analysis of PTSD participants (n = 260) and controls (n = 343) revealed no SNPs of genome-wide significance. However, several independent loci, as well as five SNPs in the PARK2 gene, were suggestively associated with PTSD (p < 5 × 10-6). PTSD-PRS was associated with PTSD diagnosis (Nagelkerke's pseudo R 2 = 0.0131, p = 0.00786), PTSD symptom severity [as measured by CAPS-5 total score (R 2 = 0.00856, p = 0.0367) and PCL-5 score (R 2 = 0.00737, p = 0.0353)], and MetS (Nagelkerke's pseudo R 2 = 0.00969, p = 0.0217). These findings suggest an association between PTSD and PARK2, corresponding with results from the largest PTSD-GWAS conducted to date. PRS analysis suggests that genetic variants associated with PTSD are also involved in the development of MetS. Overall, the results contribute to a broader goal of increasing diversity in psychiatric genetics.
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Affiliation(s)
- Patricia C. Swart
- Department of Psychiatry, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- South African Medical Research Council, Stellenbosch University Genomics of Brain Disorders Research Unit, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Leigh L. van den Heuvel
- Department of Psychiatry, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- South African Medical Research Council, Stellenbosch University Genomics of Brain Disorders Research Unit, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Cathryn M. Lewis
- Social, Genetic and Developmental Psychiatry Centre, King’s College London, London, United Kingdom
| | - Soraya Seedat
- Department of Psychiatry, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- South African Medical Research Council, Stellenbosch University Genomics of Brain Disorders Research Unit, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Sian M. J. Hemmings
- Department of Psychiatry, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
- South African Medical Research Council, Stellenbosch University Genomics of Brain Disorders Research Unit, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Swart PC, Russell VA, Dimatelis JJ. Maternal separation stress reduced prenatal-ethanol-induced increase in exploratory behaviour and extracellular signal-regulated kinase activity. Behav Brain Res 2018; 356:470-482. [PMID: 29908221 DOI: 10.1016/j.bbr.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/22/2018] [Accepted: 06/06/2018] [Indexed: 01/26/2023]
Abstract
In an attempt to better represent the aetiology of fetal alcohol spectrum disorder (FASD) and the associated psychological deficits, prenatal-ethanol exposure was followed by maternal separation in a rat model in order to account for the effects of early-life adversities in addition to in utero alcohol exposure. Extracellular signal-regulated kinase 1/2 (ERK1/2) and glycogen synthase kinase 3-β (GSK3β) are converging points for many signalling cascades and have been implicated in models of FASD and models of early-life stress. Therefore, these kinases may also contribute to the behavioural changes observed after the combination of both developmental insults. In this study, ethanol-dams voluntarily consumed a 0.066% saccharin-sweetened 10% ethanol (EtOH) solution for 10 days prior to pregnancy and throughout gestation while control-dams had ad libitumaccess to a 0.066% saccharin (sacc) solution. Whole litters were randomly assigned to undergo maternal separation (MS) for 3 h/day from P2 to P14 while the remaining litters were left undisturbed (nMS). This resulted in 4 experimental groups: control (sacc + nMS), MS (sacc + MS), EtOH (EtOH + nMS) and EtOH + MS. Throughout development, EtOH-rats weighed less than control rats. However, subsequent maternal separation stress caused EtOH + MS-rats to weigh more than EtOH-rats. In adulthood both MS- and EtOH-rats were hyperactive but the combination produced activity levels similar to that of control rats. All treated animals (MS-, EtOH- and EtOH + MS-rats) demonstrated a negative affective state shown by increased number and duration of 22 kHz ultrasonic vocalizations compared to control rats. Prenatal-ethanol exposure increased the P-GSK3β/GSK3β ratio in the prefrontal cortex (PFC) and maternal separation decreased the P-GSK3β/GSK3β ratio in the dorsal hippocampus (DH) of adult rats. However, maternal separation stress decreased the effect of prenatal-ethanol exposure on the P-ERK/ERK ratio in the PFC and DH and reduced prenatal-ethanol-induced hyperactivity. Therefore, indicating a significant interaction between prenatal-ethanol exposure and early-life stress on behaviour and the brain and may implicate P-ERK1/2 signalling in exploratory behaviour.
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Affiliation(s)
- Patricia C Swart
- University of Cape Town, Faculty of Health Sciences, Department of Human Biology, Observatory, 7925 South Africa.
| | - Vivienne A Russell
- University of Cape Town, Faculty of Health Sciences, Department of Human Biology, Observatory, 7925 South Africa.
| | - Jacqueline J Dimatelis
- University of Cape Town, Faculty of Health Sciences, Department of Human Biology, Observatory, 7925 South Africa.
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Swart PC, Currin CB, Russell VA, Dimatelis JJ. Early ethanol exposure and vinpocetine treatment alter learning- and memory-related proteins in the rat hippocampus and prefrontal cortex. J Neurosci Res 2016; 95:1204-1215. [DOI: 10.1002/jnr.23894] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 07/29/2016] [Accepted: 08/01/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Patricia C. Swart
- Department of Human Biology; Faculty of Health Sciences, University of Cape Town; Observatory Cape Town 7925 South Africa
| | - Christopher B. Currin
- Department of Human Biology; Faculty of Health Sciences, University of Cape Town; Observatory Cape Town 7925 South Africa
| | - Vivienne A. Russell
- Department of Human Biology; Faculty of Health Sciences, University of Cape Town; Observatory Cape Town 7925 South Africa
| | - Jacqueline J. Dimatelis
- Department of Human Biology; Faculty of Health Sciences, University of Cape Town; Observatory Cape Town 7925 South Africa
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