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Genetic studies in the social sciences could be augmented through the additional consideration of functional (transcriptome, methylome, metabolome) and/or multimodal genetic data when attempting to understand the genetics of social phenomena. Understanding the biological pathways linking genetics and the environment will allow scientists to better evaluate the functional importance of polygenic scores.

Background: Latinas in the United States suffer disproportionately high levels of pre- and postnatal depression. However, little is understood regarding the biopsychosocial mechanisms linking socio-environmental factors to this increase in mental health risk. The oxytocinergic system, with its roles in the stress response, social behaviour and mood regulation, may be an important modulator of this sensitivity. We have previously reported prenatal discrimination to be a significant predictor of postnatal depression in Latinas; here we tested whether sensitivity to discrimination stress might depend on oxytocinergic system activity. Methods: A sample of 148 Latina women residing in the US were assessed prenatally at 24-32 weeks' gestation and 46 weeks postnatally for perceived discrimination levels, acculturation, and depression and anxiety symptoms. Plasma oxytocin (OXT) levels and DNA methylation of the oxytocin receptor (OXTR) were measured prenatally together with genotyping for the OXTR SNP, rs53576. Results: In mothers with low OXT levels and low OXTR methylation, acculturation level was associated with postnatal depression and anxiety symptoms. No such associations were found in those with higher OXT levels and higher OXTR methylation. We also found a significant relationship between prenatal psychosocial factors (discrimination and acculturation) and postnatal depression and anxiety in carriers of the G-allele at rs53576, but not AA genotypes. Finally, OXTR methylation positively correlated with mothers reports of experiencing affiliative social touch. Moreover, social touch mediated the relationship between discrimination and postnatal depression in those with low OXTR methylation. Conclusion: These results support the hypothesis that the oxytocinergic system modulates sensitivity to prenatal stress in the development of postnatal mood and anxiety disorders in Latina mothers.

Chronic stress during early life, such as exposure to social conflict or deficits in parental care, can have persistent adverse behavioural effects. Offspring in a rodent model of maternal depression and early life stress have increased susceptibility to maternal depression themselves, suggesting a pathway by which maternal stress could be intergenerationally inherited. The overall aim of this study was to explore the genetic regulatory pathways underlying how maternal social stress and reduced care mediates stress‐related behavioural changes in offspring across generations. This study investigated a social stress‐based rat model of postpartum depression and the intergenerational inheritance of depressed maternal care where F0 (dams exposed to male intruder stress during lactation) and F1 offspring are directly exposed to social stress. RNASeq was used to investigate genomewide transcriptome changes in the hippocampus of F1 and F2 generations. Transcriptome analyses revealed differential expression of 69 genes in the F1 generation and 14 in the F2 between controls vs. social stress differences. Many of these genes were receptors and calciumbinding proteins in the F1 and involved in cellular oxidant detoxification in F2. The present data identify and characterize changes in the neural expression of key genes involved in the regulation of depression maintained between the generations, suggesting a potential neural pathway for the intergenerational transmission of depressed maternal care and maternal anxiety in the CSS model. Further work is needed to understand to what extent these results are due to molecular germline inheritance and/or the social propagation of deficits in maternal care.

Background: The APOE ɛ4 allele is the strongest known genetic risk factor for sporadic Alzheimer’s disease (AD). The neighboring TOMM40 gene has also been implicated in AD due to its close proximity to APOE. Objective: Here we tested whether methylation of the TOMM40-APOE locus may influence ApoE protein levels and AD pathology. Methods: DNA methylation levels across the TOMM40-APOE locus and ApoE levels were measured in superior frontal gyrus tissues of 62 human brains genotyped for APOE and scored for AD neuropathology. Results: Methylation levels within the TOMM40 CpG island in the promoter or APOE CpG island in Exon 4 did not differ between APOE ɛ4 carriers versus non-carriers. However, APOE ɛ4 carriers had significantly higher methylation the APOE promoter compared with non-carriers. Although DNA methylation at TOMM40, APOE promoter region, or APOE did not differ between AD pathological groups, there was a negative association between TOMM40 methylation and CERAD scores. ApoE protein concentrations did not significantly different between APOE ɛ4 carriers and non-carriers, or between AD pathological groups. Finally, there was no correlation between ApoE protein concentrations and DNA methylation levels. Conclusion: APOE gene methylation may not be affected by genotype, relate to AD pathology or ApoE protein levels in the superior frontal gyrus, though, DNA methylation at the ApoE promoter differed between genotype. DNA methylation at TOMM40 associated with amyloid-β plaques and longitudinal fluid intelligence. In sum, these results suggest a complicated regulation of the TOMM40-APOE locus in the brain in controlling ApoE protein levels and AD neuropathology.

Latina mothers, who have one of the highest fertility rates among ethnic groups in the United States (US), often experience discrimination. Psychosocial influences during pregnancy, such as stress, promotes inflammation. However, the role of epigenetic markers of inflammation as a mediator between, and predictor of, maternal discrimination stress and neuropsychiatric outcomes has not been extensively studied. The current study investigates the role of DNA methylation at FOXP3 Treg-cell-specific demethylated region (TSDR), as a marker of regulatory T (Treg) cells that are important negative regulators of inflammation, and at the promoter of tumour necrosis factor-alpha (TNF-α), an important pro-inflammatory cytokine in associations between discrimination stress during pregnancy and depression and anxiety symptomology. A sample of 148 Latina women residing in the US (mean age 27.6 years) were assessed prenatally at 24–32 weeks’ gestation and 4–6 weeks postnatally for perceived discrimination exposure (Everyday Discrimination Scale, EDS), emotional distress (depression, anxiety, perinatal-specific depression), acculturation, and acculturative stress. DNA methylation levels at the FOXP3 and TNFα promoter regions from blood samples collected at the prenatal stage were assessed by bisulphite pyrosequencing. Regression analyses revealed that prenatal EDS associated with postnatal emotional distress, depression and anxiety symptoms only in those individuals with higher than mean levels of FOXP3 TSDR and TNFα promoter methylation; no such significant associations were found in those with lower than mean levels of methylation for either. We further found that these relationships were mediated by TNFα only in those with high FOXP3 TSDR methylation, implying that immunosuppression via TNFα promoter methylation buffers the impact of discrimination stress on postpartum symptomatology. These results indicate that epigenetic markers of immunosuppression and inflammation play an imp

BACKGROUND:An early symptom of Alzheimer's disease (AD) is a disturbance of the circadian rhythm that is associated with disrupted sleep/wake cycles. OBJECTIVE:To investigate if BMAL1, a key gene that drives the circadian cycle, is epigenetically regulated in brains in relation to longitudinal changes in cognition, sleep quality, and AD neuropathology. METHODS:Frontal cortex tissues were acquired from the Manchester Brain Bank (N = 96). DNA methylation at six CpG sites at the promoter of BMAL1, determined using bisulfite pyrosequencing, was tested for associations with Braak stage, CERAD score, and Thal phase, longitudinal changes in cognition, sleep measurements, and cross-section measures of depressive symptoms (BDI score). RESULTS:Methylation across all the CpGs strongly correlated with each other. We found increased CpG2 methylation with higher Braak (t(92) = 2.47, p = 0.015) and CERAD (t(94) = 2.04, p = 0.044) stages. No significance was found between longitudinal fluid intelligence, processing speed, and memory tests, but methylation at CpG1 (r = 0.20, p = 0.05) and CpG4 (r = 0.20, p = 0.05) positively correlated with vocabulary. CpG2 positively correlated with cross-sectional fluid intelligence (r = 0.20 p = 0.05) and vocabulary (r = 0.22 p = 0.03). Though longitudinal analysis revealed no significance between sleep duration, midsleep, and efficiency for any of the CpG sites, CpG3 (B = 0.03, 95% CI = 0.00/0.06, p = 0.03) and CpG5 (B = 0.04, 95% CI = 0.01,0.07, p = 0.01) significantly correlated with night wake. CpG4 correlated with depressive symptoms (B = -0.27, 95% CI=0.49/-0.05, p = 0.02). CONCLUSION:Methylation of BMAL1 associated with tau pathology, changes in cognitive measures, a measure of sleep and depressive symptoms, suggesting an involvement of the circadian cycle.

Background: Neuropeptides play an essential role in reproduction, with many of their receptors found throughout both male and female reproductive tracts (1). Vasopressin (VP), with a key role in homeostasis, is also important in regulating reproductive behaviours (2). Though two relatively old studies have detected VP in human and Bull semen little is known about its possible role in human sperm function (1, 3, 4). The present study aims to explore the role of VP on human sperm function. Methods: Semen samples were obtained from consenting males following NHS and Faculty approval. Vasopressin receptor 2 (VPR2) expression on sperm was analysed via immunostaining and seminal plasma vasopressin concentrations detected by ELISA. Sperm motility and kinematics were measured via CASA (SAMi). Sperm calcium measurements were carried out using fluorescent microplate assays. Acrosome-reacted sperm were detected using SEM. Aquaporin-2 (AQP2) expression in sperm was detected using dot blots and western blots. Results: We confirm the presence of VP in human semen; at concentrations of 143.4 -- 2827.9 pg/ml (n = 74). VPR2 was found localised to the sperm acrosomal region. Treatment of human sperm with desmopressin and VP significantly modulated motility, linearity and curvilinear velocity (p = < 0.05) and induced a significant calcium response (p = < 0.05). VP-treatment led to a 3-fold increase in acrosome-reacted sperm (Vehicle 1.8%, VP 6.2%). Both glycosylated and non-glycosylated isoforms of AQP2 were found in untreated, vasopressin treated and capacitated sperm. Conclusions: The variations in semen VP concentrations, together with sperm responses to VP and agonist treatments and the occurrence of VPR2 and AQP2 in human sperm suggests a possible mechanistic role of VP in sperm function. Further work is needed to understand the role of VP in fertility and the potential use of VP as a biomarker of reproductive health.

Objectives: Findings from observational studies and clinical trials on the associations between vitamin E and dementia remain controversial. Here we conducted a meta-analysis to determine the difference in blood tocopherols levels between patients with Alzheimer's disease (AD) or age-related poor cognitive function and healthy controls.Methods: Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated and entered into a random effects model. Study quality, heterogeneity and publication bias were also investigated.Results: Thirty-one articles were included in the meta-analysis, which included analyses for α-, β-, γ- and δ-tocopherols. These results indicated that individuals with AD or age-related cognitive deficits and mild cognitive impairment (MCI) had lower circulatory concentrations of α-tocophenol compared with healthy controls (AD: SMD = -0.97, 95% confidence interval [CI] = -1.27 to -0.68, Z = 6.45, P < 0.00001; age-related cognitive deficits and MCI: SMD = -0.72, 95% CI = -1.12 to -0.32, Z = -3., P < 0.0005). Levels of β-, γ- and δ-tocophenols did not significantly differ between groups of AD and age-related cognitive deficits compared to controls.Discussion: These results suggest that lower α-tocopherol levels have a strong association with AD and MCI supporting evidence for the role of diet and vitamin E in AD risk and age-related cognitive decline.

Evolutionary hypotheses predict that male fetuses are more vulnerable to poor maternal conditions (Sex-biased Maternal Investment), but female fetuses are at greater risk of glucocorticoid-mediated disorders where there is a mismatch between fetal and postnatal environments (Predictive Adaptive Response). Self-reported prenatal and postnatal depression and maternal report of child anxious-depressed symptoms at 2.5, 3.5 and 5.0 years were obtained from an 'extensive' sample of first-time mothers (N = 794). Salivary NR3C1 1-F promoter methylation was assayed at 14 months in an 'intensive' subsample (n = 176) and stratified by psychosocial risk. Generalised structural equation models were fitted and estimated by maximum likelihood to allow the inclusion of participants from both intensive and extensive samples. Postnatal depression was associated with NR3C1 methylation and anxious-depressed symptoms in daughters of mothers with low prenatal depression (prenatal-postnatal depression interaction for methylation, p < 0.001; for child symptoms, p = 0.011). In girls, NR3C1 methylation mediated the association between maternal depression and child anxious-depressed symptoms. The effects were greater in girls than boys: the test of sex differences in the effect of the prenatal-postnatal depression interaction on both outcomes gave X2 (2) = 5.95 (p = 0.051). This was the first human study to show that epigenetic and early behavioural outcomes may arise through different mechanisms in males and females.

Background:Brain-derived neurotrophic factor (BDNF) is essential for neurogenesis and has been implicated in Alzheimer’s disease (AD). However, few studies have investigated together the epigenetic, transcriptional, and translational regulation of this peptide in the brain in relation to AD. Objective:To investigate mechanisms underlying how BDNF is possibly dysregulated in the brain in relation to aging and AD neuropathology. Methods:Prefrontal cortex tissues were acquired from the Manchester Brain Bank (N = 67). BDNF exon I, and exon IV-containing transcripts and total long 3’ transcript gene expression were determined by quantitative PCR and bisulfite pyrosequencing was used to quantify DNA methylation within promoters I and IV. Protein concentrations were quantified via ELISA. Results:BDNF exon IV and total long 3’ isoform gene expression levels negatively associated with donor’s age at death (IV: r = –0.291, p = 0.020; total: r = –0.354, p = 0.004). Expression of BDNF exon I- containing isoform was significantly higher in Met-carriers of the rs6265 variant, compared to Val-homozygotes, when accounting for donor ages (F = 6.455, p = 0.014). BDNF total long 3’ transcript expression was significantly lower in those with early AD neuropathology, compared to those without any neuropathology (p = 0.021). There were no associations between BDNF promoter I and IV methylation or protein levels with ages, rs6265 genotype or AD neuropathology status. Conclusion:Prefrontal cortex BDNF gene expression is associated with aging, rs6265 carrier status, and AD neuropathology in a variant-specific manner that seems to be independent of DNA methylation influences.

With increasing life expectancy, age-associated cognitive impairment is an escalating problem worldwide. Inflammation is one of the features that characterises cognitive decline and can stimulate neurodegeneration. Interleukin 6 (IL-6) is a cytokine frequently associated with a pro-inflammatory phenotype and increased levels have been associated with the pathogenesis of dementia. The rs1800796 polymorphism in the promoter region of IL-6 gene was previously shown to influence IL-6 expression and therefore we hypothesised this gene polymorphism would be associated with IL-6 plasma levels and cognitive performance of older adults. The present study investigated the association of the rs1800796 polymorphism on plasma IL-6 levels and cognition in healthy older adults (n = 207, 74.6 ± 3.4 years, 51% female) that participated in a Pan-European project (MyoAge). The participants were assessed for working memory capacity, executive functioning, episodic memory and global cognition using the Cambridge Neuropsychological Test Automated Battery CANTAB. Fasting plasma IL-6 levels were measured by ELISA and genotyping was performed using the KASP assay. Results showed that the rs1800796 polymorphism was in Hardy-Weinberg equilibrium (P =.16) with the minor allele (C) showing a frequency of 6.3%. There were no differences in plasma IL-6 concentrations between the GG-homozygotes and C-allele carriers (P =.22). The C-allele carriers performed worse on a measure of executive functioning (P =.035) and had lower global cognitive scores (P =.045), compared to GG-homozygotes. These differences remained significant after accounting for age, sex and prior cognitive abilities (P <.05 for both). There were no differences in measures of memory (episodic and working) between the genotypes group. These findings suggest that the rs1800796 variant may be detrimental for executive functioning, but not memory, in healthy older adults.