Estrogen receptor alpha gene variants and major depressive episodes

Sex-Specific Association Between Polymorphisms in Estrogen Receptor Alpha Gene (ESR1) and Depression: A Genome-Wide Association Study of All of Us and UK Biobank Data

Major depressive disorder (MDD) is prevalent worldwide, substantially and negatively impacting both the quality and length of life of 280 million people globally. The genetic risk factors of MDD have been studied in various previous research, but the findings lack consistency. Sex/gender and racial/ethnic disparities have been reported; however, many previous genetic studies, represented by large-scale genome-wide association studies (GWASs) are known to lack diversity in the study cohorts. All of Us is a biorepository aiming to focus on the historically underrepresented groups. We perform GWASs for the MDD phenotype, using over 200,000 participants' genotypes and carry out sex- and racial/ethnic-specific subgroup studies. We identified a risk locus (chr6:151945242) in Estrogen Receptor Alpha Gene (ESR1) (p = 1.70 × 10 - 9 $1.70\times {10}^{-9}$ ), and further confirmed the genetic association is sex-specific. The single-nucleotide polymorphism (SNP) chr6:151945242 was significant only in the male group, but not in the female group. These findings were replicated in the UK Biobank and echo with existing studies on the ESR1 gene and depressive disorders. Our results indicate that the All of Us program is a reliable resource for GWAS, as well as shedding light on further investigation of sex- and racial/ethnic-specific genome association, especially in underrepresented groups of the US population.

A Common Genetic Factor Underlies Genetic Risk for Gynaecological and Reproductive Disorders and Is Correlated with Risk to Depression

INTRODUCTION

Sex steroid hormone fluctuations may underlie both reproductive disorders and sex differences in lifetime depression prevalence. Previous studies report high comorbidity among reproductive disorders and between reproductive disorders and depression. This study sought to assess the multivariate genetic architecture of reproductive disorders and their loading onto a common genetic factor and investigated whether this latent factor shares a common genetic architecture with female depression, including perinatal depression (PND).

METHOD

Using UK Biobank and FinnGen data, genome-wide association meta-analyses were conducted for nine reproductive disorders, and genetic correlation between disorders was estimated. Genomic Structural Equation Modelling identified a latent genetic factor underlying disorders, accounting for their significant genetic correlations. SNPs significantly associated with both latent factor and depression were identified.

RESULTS

Excellent model fit existed between a latent factor underlying five reproductive disorders (χ2 (5) = 6.4; AIC = 26.4; CFI = 1.00; SRMR = 0.03) with high standardised loadings for menorrhagia (0.96, SE = 0.05); ovarian cysts (0.94, SE = 0.05); endometriosis (0.83, SE = 0.05); menopausal symptoms (0.77, SE = 0.10); and uterine fibroids (0.65, SE = 0.05). This latent factor was genetically correlated with PND (rG = 0.37, SE = 0.15, p = 1.4e-03), depression in females only (rG = 0.48, SE = 0.06, p = 7.2e-11), and depression in both males and females (MD) (rG = 0.35, SE = 0.03, p = 1.8e-30), with its top locus associated with FSHB/ARL14EP (rs11031006; p = 9.1e-33). SNPs intronic to ESR1, significantly associated with the latent factor, were also associated with PND, female depression, and MD.

CONCLUSION

A common genetic factor, correlated with depression, underlies risk of reproductive disorders, with implications for aetiology and treatment. Genetic variation in ESR1 is associated with reproductive disorders and depression, highlighting the importance of oestrogen signalling for both reproductive and mental health.

Bioinformatics and computational chemistry approaches to explore the mechanism of the anti-depressive effect of ligustilide

Depression affects people with multiple adverse outcomes, and the side effects of antidepressants are troubling for depression sufferers. Aromatic drugs have been widely used to relieve symptoms of depression with fewer side effects. Ligustilide (LIG) is the main component of volatile oil in angelica sinensis, exhibiting an excellent anti-depressive effect. However, the mechanisms of the anti-depressive effect of LIG remain unclear. Therefore, this study aimed to explore the mechanisms of LIG exerting an anti-depressive effect. We obtained 12,969 depression-related genes and 204 LIG targets by a network pharmacology approach, which were intersected to get 150 LIG anti-depressive targets. Then, we identified core targets by MCODE, including MAPK3, EGF, MAPK14, CCND1, IL6, CASP3, IL2, MYC, TLR4, AKT1, ESR1, TP53, HIF1A, SRC, STAT3, AR, IL1B, and CREBBP. Functional enrichment analysis of core targets showed a significant association with PI3K/AKT and MAPK signaling pathways. Molecular docking showed strong affinities of LIG with AKT1, MAPK14, and ESR1. Finally, we validated the interactions between these proteins and LIG by molecular dynamics (MD) simulations. In conclusion, this study successfully predicted that LIG exerted an anti-depressive effect through multiple targets, including AKT1, MAPK14, and ESR1, and the pathways of PI3K/AKT and MAPK. The study provides a new strategy to explore the molecular mechanisms of LIG in treating depression.

Association Between Polymorphisms in Estrogen Receptor Genes and Depression in Women: A Meta-Analysis

Objective: It is suggested that estrogen receptors (ERs) might be associated with the disproportionate vulnerability of women to depressive episodes. Several variants in ER-alpha (ERα) and ER-beta (ERβ) have been linked to depression, but the results were not consistent. Hence, we conducted a meta-analysis to evaluate the association between ERα/ERβ and depression in a cohort of women.

Methods: A comprehensive literature search was performed in public databases. The genetic association between polymorphisms in Erα/ERβ and depression risk in a cohort of women was evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). Cochran’s Q test and the I² index were used to evaluate heterogeneity.

Results: In total, 10 studies and 4 SNPs (rs2234693, rs9340799, rs4986938, rs1256049) were included in our meta-analysis. rs2234693 genotype was significantly associated with the risk of depression in women by dominant model (CC + CT vs TT, OR = 1.30, 95% CI: 1.09–1.55, p = 0.0031), recessive model (CC vs CT + TT, OR = 1.64, 95% CI: 1.00–2.67, p = 0.0478), additive model (CC vs TT, OR = 1.93, 95% CI: 1.12–3.35, p = 0.0189) and allelic model (C vs T, OR = 1.24, 95% CI: 1.10–1.39, p = 0.0003). For rs9340799, the frequencies of risk genotypes according to the dominant (GG + GA vs AA, OR = 1.47, 95% CI = 1.10–1.98, p = 0.0096, I² = 0%, p = 0.43) and allelic (G vs A, OR = 1.33, 95% CI: 1.04–1.69, p = 0.0236, I² = 0%, p = 0.39) models were significantly lower in women with depression than in controls within the Asian subgroup. For rs1256049, risk genotypes were significantly more frequent in depressed subjects than in controls under the dominant model (AA+ GA vs GG, OR = 1.62, 95% CI: 1.19–2.21, p = 0.0024) and the allelic model (A vs G, OR = 1.35, 95% CI: 1.07–1.72, p = 0.012) after sensitivity analysis by omitting one study which induce the heterogeneity.

Conclusions: The current meta-analysis is the first and most comprehensive investigation of the association between ERs and depression in women, and the findings support the concept that ERs participate in the etiology of sex heterogeneity in depression.

Integrated Network Pharmacology and Comprehensive Bioinformatics Identifying the Mechanisms and Molecular Targets of Yizhiqingxin Formula for Treatment of Comorbidity With Alzheimer’s Disease and Depression

Background: The Yizhiqinxin formula (YZQX) has been used to treat Alzheimer’s disease (AD) or major depression disorder (MDD). However, its specific underlying mechanisms and therapeutic targets remain unclear.

Methods: The ingredients and putative targets of YZQX were screened using the TCMSP and Drugbank databases. Next, the GEO database was used to retrieve relevant differentially expressed genes (DEGs) in AD or MDD and normal tissues. The PPI network was established, merged, and further screened to identify the main ingredients and core targets of YZQX against AD and MDD comorbidities. We performed enrichment analysis of core targets to identify biological processes and pathways. Finally, AutoDock software was used to validate the binding affinity between the crucial targets of direct action and their corresponding ingredients.

Results: A total of 43 ingredients were identified from YZQX, of which 43 were screened to yield 504 targets. By establishing the PPI network, 92 targets were regarded as targets of YZQX against AD and MDD comorbidities in the core network. Promising targets (HSP90AA1, ESR1, AKT1, VCAM1, EGFR, CDK1, MAPK1, CDK2, MYC, HSPB1, and HSPA5) and signaling pathways (PI3K-Akt signaling pathway, ubiquitin-mediated proteolysis, MAPK signaling pathway, etc.) were filtered and refined to elucidate the underlying mechanism of YZQX against AD and MDD comorbidities. Molecular docking confirmed the ingredients of YZQX (quercetin and kaempferol) could bind well to multiple crucial targets.

Conclusion: The ingredients of YZQX, such as quercetin and kaempferol, might treat AD and MDD comorbidities by acting on multiple targets and pathways.

Shared genetic liability between major depressive disorder and osteoarthritis

Aims

Deciphering the genetic relationships between major depressive disorder (MDD) and osteoarthritis (OA) may facilitate an understanding of their biological mechanisms, as well as inform more effective treatment regimens. We aim to investigate the mechanisms underlying relationships between MDD and OA in the context of common genetic variations.

Methods

Linkage disequilibrium score regression was used to test the genetic correlation between MDD and OA. Polygenic analysis was performed to estimate shared genetic variations between the two diseases. Two-sample bidirectional Mendelian randomization analysis was used to investigate causal relationships between MDD and OA. Genomic loci shared between MDD and OA were identified using cross-trait meta-analysis. Fine-mapping of transcriptome-wide associations was used to prioritize putatively causal genes for the two diseases.

Results

MDD has a significant genetic correlation with OA (r_g = 0.29) and the two diseases share a considerable proportion of causal variants. Mendelian randomization analysis indicates that genetic liability to MDD has a causal effect on OA (b_xy = 0.24) and genetic liability to OA conferred a causal effect on MDD (b_xy = 0.20). Cross-trait meta-analyses identified 29 shared genomic loci between MDD and OA. Together with fine-mapping of transcriptome-wide association signals, our results suggest that Estrogen Receptor 1 (ESR1), SRY-Box Transcription Factor 5 (SOX5), and Glutathione Peroxidase 1 (GPX1) may have therapeutic implications for both MDD and OA.

Conclusion

The study reveals substantial shared genetic liability between MDD and OA, which may confer risk for one another. Our findings provide a novel insight into phenotypic relationships between MDD and OA.

Cite this article: Bone Joint Res 2022;11(1):12–22.

Quercetin exerts antidepressant and cardioprotective effects in estrogen receptor α-deficient female mice via BDNF-AKT/ERK1/2 signaling

Brain-derived neurotrophic factor (BDNF) is the potential link between depression and cardiovascular disease and estrogen receptor α (ERα), an estrogen-mediated major regulator, plays an important role in protecting against depression and cardiovascular disease. However, the relationship between BDNF and ERα remains obscure. Herein, quercetin (QUE), a kind of plant flavonoids and existed in many vegetables and fruits, was found to simultaneously reverse ERα-/--induced depression-like and cardiac dysfunction by reducing immobility time in the tail suspension test (TST) and forced swimming test (FST), and decreasing systolic blood pressure and activating the apoptosis-related proteins, BDNF, tropomyosin-related kinase B (TrkB), protein kinase B (AKT), and extracellular regulatory protein kinase (ERK1/2) in the hippocampal and cardiac tissues of female mice. These findings suggested that ERα might be involved in the regulation of BDNF activity, thereby regulating depression-like and cardiovascular responses in female mice, and QUE exerted significant antidepressant and cardioprotective effects, at least in part, through BDNF-TrkB-AKT/ERK1/2 to effectively inhibit ERα-/--induced hippocampal and cardiac dysfunction.

Is Postpartum Depression Different From Depression Occurring Outside of the Perinatal Period? A Review of the Evidence

Whether a major depressive episode occurring in the postpartum period (i.e., postpartum depression [PPD]) is sufficiently distinct from major depressive episodes occurring at other times (i.e., major depressive disorder) to warrant a separate diagnosis is a point of debate with substantial clinical significance. The evidence for and against diagnostic distinction for PPD is reviewed with respect to epidemiology, etiology, and treatment. Overall, evidence that PPD is distinct from major depressive disorder is mixed and is largely affected by how the postpartum period is defined. For depression occurring in the early postpartum period (variably defined, but typically with onset in the first 8 weeks), symptom severity, heritability, and epigenetic data suggest that PPD may be distinct, whereas depression occurring in the later postpartum period may be more similar to major depressive disorder occurring outside of the perinatal period. The clinical significance of this debate is considerable given that PPD, the most common complication of childbirth, is associated with immediate and enduring adverse effects on maternal and offspring morbidity and mortality. Future research investigating the distinctiveness of PPD from major depressive disorder in general should focus on the early postpartum period when the rapid decline in hormones contributes to a withdrawal state, requiring profound adjustments in central nervous system function.

Reveals of New Candidate Active Components in Hemerocallis Radix and Its Anti-Depression Action of Mechanism Based on Network Pharmacology Approach

The global depression population is showing a significant increase. Hemerocallis fulva L. is a common Traditional Chinese Medicine (TCM). Its flower buds are known to have ability to clear away heat and dampness, detoxify, and relieve depression. Ancient TCM literature shows that its roots have a beneficial effect in calming the spirit and even the temper in order to reduce the feeling of melancholy. Therefore, it is inferred that the root of Hemerocallis fulva L. can be used as a therapeutic medicine for depression. This study aims to uncover the pharmacological mechanism of the antidepressant effect of Hemerocallis Radix (HR) through network pharmacology method. During the analysis, 11 active components were obtained and screened using ADME—absorption, distribution, metabolism, and excretion— method. Furthermore, 267 HR targets and 740 depressive disorder (DD) targets were gathered from various databases. Then protein–protein interaction (PPI) network of HR and DD targets were constructed and cluster analysis was applied to further explore the connection between the targets. In addition, gene ontology (GO) enrichment and pathway analysis was applied to further verify that the biological process related to the target protein is associated with the occurrence of depression disorder. In conclusion, the most important bioactive components—anthraquinone, kaempferol, and vanillic acid—can alleviate depression symptoms by regulating MAOA, MAOB, and ESR1. The proposed network pharmacology strategy provides an integrating method to explore the therapeutic mechanism of multi-component drugs on a systematic level.

Depressive behavior induced by nonylphenol and its effect on the expression of ER-α and ER-β in nerve cells of rats

OBJECTIVE

To investigate the effects of nonylphenol (NP) exposure on the depressive behavior in rats, and the effects of the expressions of estrogen receptor-α (ER-α) and estrogen receptor-β (ER-β) in nerve cells in vivo and vitro.

METHODS

Forty male SD rats were randomly divided into 4 groups: blank control group (0 mg/kg), low dose group (0.4 mg/kg), middle dose group (4 mg/kg) and high dose group (40 mg/kg), which were exposed to NP for 180 days. The exposure dose of NP in HT22 was 20μM, which was divided into4 groups: blank control group, NP group, ICI182780 group and ICI182780+NP group.

RESULTS

In vivo, in the open field experiment, the number of entries in the central area and duration of attention in central square decreased gradually in the NP high dose group compared with the control (F = 3.561, p = .029). In forced swimming experiment, with the increase of NP dose, the immobility time increased, and the increasing degree of middle dose group and high dose group was higher than that of the low dose group (F = 3.047, p = .048). The concentrations of serum dopamine (DA) in the middle dose and high dose groups decreased greatly compared with the control (F = 3.967, p = .023). NP exposure at the doses of 4 mg/kg and 40 mg/kg induced an increase in the level of serum corticosterone compared to the control (F = 11.536, p<.001). Compared with the control group, the expression of ER-β decreased gradually with an increase of NP dose in the NP treatment groups (F = 4.513, p = .014). In vitro, the activity of HT22 cells decreased with an increase of NP dose (F = 316.6, p<.001). When the dose of NP was 200 μM, the growth inhibition rate of HT22 cells was (0.54±0.11)%. The expression levels of ER-α and ER-β in ICI182780+NP group was lower than those in the control and ICI182780 groups, but higher than those in the NP group (F = 1.592, p=.266; F = 10.166, p=.004).

CONCLUSION

Long-term exposure to NP could induce the alterations in depressive behavior, and the levels of neurotransmitters as well as the expression of ER in the hippocampus of rats. Moreover, NP could reduce the activity of HT22 cells and decrease the expression levels of ER-α and ER-β in vitro.

Genetic Intersections of Language and Neuropsychiatric Conditions

PURPOSE OF REVIEW

To better understand the shared basis of language and mental health, this review examines the behavioral and neurobiological features of aberrant language in five major neuropsychiatric conditions. Special attention is paid to genes implicated in both language and neuropsychiatric disorders, as they reveal biological domains likely to underpin the processes controlling both.

RECENT FINDINGS

Abnormal language and communication are common manifestations of neuropsychiatric conditions, and children with impaired language are more likely to develop psychiatric disorders than their peers. Major themes in the genetics of both language and psychiatry include master transcriptional regulators, like FOXP2; key developmental regulators, like AUTS2; and mediators of neurotransmission, like GRIN2A and CACNA1C.

Development of Postpartum Depression in Pregnant Women with Preeclampsia: A Retrospective Study

Background

Postpartum depression (PPD) and preeclampsia (PE) are both common diseases in obstetrics that affect maternal health and infant development. However, the relationship between the two diseases still requires clarification.

Objective

The purpose of this study was to (1) determine the incidence rate of PPD in patients with PE and (2) identify the association between the prevalence of PPD and the severity of PE.

Methods

We conducted a retrospective analysis of women with and without PE who delivered between January 1, 2017, and August 30, 2018, in the First Affiliated Hospital of Chongqing Medical University. We used a questionnaire survey methodology that included the Edinburgh Postnatal Depression Scale (EPDS) to test the influence of PE on the development of new-onset PPD in the 6 weeks after delivery. We determined PPD based on a score ≥10 on the EPDS. Bivariate analysis was used to compare data between the two groups.

Results

A total of 180 women participated in this study. Thirty-five people screened positive for PPD, while the remaining 145 screened negative. The prevalence of PPD was 26.67% (24/90) in patients with PE, which was two times the prevalence in normal women (12.22%). Multiple logistic regression showed that women who had PE had nearly 3-fold increased odds of PPD compared to normal women and the risk of PPD increased with the aggravation of PE. Patients with severe PE had a more than 4-fold increased risk of screening positive for PPD.

Conclusion

PE was independently associated with PPD. Furthermore, the risk of PPD seemed to increase with the aggravation of PE. Thus, additional prevention efforts and support methods should be provided for women with PE to reduce the incidence of PPD.

Sex-Specific Involvement of Estrogen Receptors in Behavioral Responses to Stress and Psychomotor Activation

Fluctuating hormone levels, such as estradiol might underlie the difference in the prevalence of psychiatric disorders observed in women vs. men. Estradiol exert its effects primarily through binding on the two classical estrogen receptor subtypes, alpha (ERα) and beta (ERβ). Both receptors have been suggested to a have role in the development of psychiatric disorders, however, most of the current literature is limited to their role in females. We investigated the role of estrogen receptors on cognition (novel-object recognition), anxiety (open-field test, elevated-plus maze, and light/dark box), stress-responsive behaviors (forced-swim test, learned helplessness following inescapable shock, and sucrose preference), pre-pulse inhibition (PPI) and amphetamine-induced hyperlocomotion in both male and female mice either lacking the ERα or ERβ receptor. We found that female Esr1 ^-/- mice have attenuated pre-pulse inhibition, whereas female Esr2 ^-/- mice manifested enhanced pre-pulse inhibition. No pre-pulse inhibition difference was observed in male Esr1 ^-/- and Esr2 ^-/- mice. Moreover, amphetamine-induced hyperlocomotion was decreased in male Esr1 ^-/-, but not Esr2 ^-/- mice, while female Esr1 ^-/- and Esr2 ^-/- mice showed an enhanced response. Genetic absence of ERα did not alter the escape capability or sucrose preference following inescapable shock in both male and female mice. In contrast, female, but not male Esr2 ^-/- mice, manifested decreased escape failures compared with controls. Lack of Esr2 gene in male mice was associated with decreased sucrose preference following inescapable shock, suggesting susceptibility for development of anhedonia following stress. No sucrose preference differences were found in female Esr2 ^-/- mice following inescapable shock stress. Lastly, we demonstrated that lack of Esr1 or Esr2 genes had no effect on memory and anxiety-like behaviors in both male and female mice. Our findings indicate a differential sex-specific involvement of estrogen receptors in the development of stress-mediated maladaptive behaviors as well as psychomotor activation responses suggesting that these receptors might act as potential treatment targets in a sex-specific manner.

Facial Sadness Recognition is Modulated by Estrogen Receptor Gene Polymorphisms in Healthy Females

Polymorphisms of the estrogen receptor ESR1 and ESR2 genes have been linked with cognitive deficits and affective disorders. The effects of these genetic variants on emotional processing in females with low estrogen levels are not well known. The aim was to explore the impact of the ESR1 and ESR2 genes on the responses to the facial emotion recognition task in females. Postmenopausal healthy female volunteers were genotyped for the polymorphisms Xbal and PvuII of ESR1 and the polymorphism rs1256030 of ESR2. The effect of these polymorphisms on the response to the facial emotion recognition of the emotions happiness, sadness, disgust, anger, surprise, and fear was analyzed. Females carrying the P allele of the PvuII polymorphism or the X allele of the Xbal polymorphism of ESR1 easily recognized facial expressions of sadness that were more difficult for the women carrying the p allele or the x allele. They displayed higher accuracy, fast response time, more correct responses, and fewer omissions to complete the task, with a large effect size. Women carrying the ESR2 C allele of ESR2 showed a faster response time for recognizing facial expressions of anger. These findings link ESR1 and ESR2 polymorphisms in facial emotion recognition of negative emotions.

Estrogen receptor α drives pro-resilient transcription in mouse models of depression

Most people exposed to stress do not develop depression. Animal models have shown that stress resilience is an active state that requires broad transcriptional adaptations, but how this homeostatic process is regulated remains poorly understood. In this study, we analyze upstream regulators of genes differentially expressed after chronic social defeat stress. We identify estrogen receptor α (ERα) as the top regulator of pro-resilient transcriptional changes in the nucleus accumbens (NAc), a key brain reward region implicated in depression. In accordance with these findings, nuclear ERα protein levels are altered by stress in male and female mice. Further, overexpression of ERα in the NAc promotes stress resilience in both sexes. Subsequent RNA-sequencing reveals that ERα overexpression in NAc reproduces the transcriptional signature of resilience in male, but not female, mice. These results indicate that NAc ERα is an important regulator of pro-resilient transcriptional changes, but with sex-specific downstream targets.

Estrogen levels, emotion regulation, and emotional symptoms of women with premenstrual dysphoric disorder: The moderating effect of estrogen receptor 1α polymorphism

BACKGROUND

This study evaluated the association between estrogen levels, emotion regulation, depression, anxiety, and stress of women with premenstrual dysphoric disorder (PMDD). We also evaluated the moderating effect of estrogen receptor (ESR) α-Xbal polymorphism on the aforementioned association.

METHODS

A total of 100 women were diagnosed with PMDD based on psychiatric interviews and a prospective investigation of 3 menstrual cycles. A total of 96 normal individuals were recruited as controls. Their estrogen levels, depression, anxiety, stress, and ESR α-Xbal polymorphism in both premenstrual and follicular phases were assessed, and these data were included in the final analysis.

RESULTS

The PMDD group had high depression, anxiety, and stress and low emotional adjusting and tolerating in the premenstrual phase. Emotional adjustment was negatively associated with depression, anxiety and stress. No association was observed between PMDD and estrogen level. However, premenstrual estrogen level was negatively correlated with anxiety and stress in women with PMDD. The association was only significant in G carriers of ESR α-Xbal, as was the difference in premenstrual emotion regulation between the PMDD and control groups.

CONCLUSIONS

The results demonstrate the association between estrogen and anxiety in PMDD, supporting the claim that women with PMDD differ in their responses to normal estrogen levels. Furthermore, this association and dysfunctional emotional regulation in PMDD existed only among the G carriers of ESR α-Xbal polymorphism. Future studies should investigate the effect of estrogen on brain functions involving emotional regulation in women with PMDD, stratified by ESR α-Xbal polymorphism.

Polymorphisms in sex steroid receptors: From gene sequence to behavior

Sex steroid receptors have received much interest as potential mediators of human behaviors and mental disorders. Candidate gene association studies have identified about 50 genetic variants of androgen and estrogen receptors that correlate with human behavioral phenotypes. Because most of these polymorphisms lie outside coding regions, discerning their effect on receptor function is not straightforward. Thus, although discoveries of associations improve our ability to predict risk, they have not greatly advanced our understanding of underlying mechanisms. This article is intended to serve as a starting point for psychologists and other behavioral biologists to consider potential mechanisms. Here, I review associations between polymorphisms in sex steroid receptors and human behavioral phenotypes. I then consider ways in which genetic variation can affect processes such as mRNA transcription, splicing, and stability. Finally, I suggest ways that hypotheses about mechanism can be tested, for example using in vitro assays and/or animal models.

The role of allelic variation in estrogen receptor genes and major depression in the Nurses Health Study

PURPOSE

The role of exogenous and endogenous sex hormones in the etiology of depression remains elusive, in part because sex hormone variation is often correlated with behaviors, life stage changes, and other factors that may influence depression. Estrogen receptor alpha (ESR1) and beta (ESR2) are known to regulate gene expression and estrogen response in areas of the brain associated with major depression and are unlikely to be correlated with exogenous factors that may influence depression.

METHODS

We examined whether functional polymorphisms in these genes are associated with lifetime major depression and chronic major depression among a sample of women from the Nurses' Health Study II (N = 2527). DSM-IV depressive disorder symptoms were assessed by structured interview in 2007. Genotyping was performed on DNA extracted from blood using Taq-man.

RESULTS

Women with the AA alleles of ESR2 RS4986938 had the higher prevalence of lifetime major depression than women with other allele frequencies (36.7 % for those with AA versus 28.5 % with GA and 29.1 % with GG, p = 0.02) and chronic major depression (14.7 % for those with AA versus 9.3 % with GA and 9.1 % with GG, p = 0.01). History of post-menopausal hormone (PMH) use modified the association of ESR1 polymorphism RS2234693 with any lifetime depression; specifically, those with the TT allele had the highest risk of lifetime depression among PMH users, and the lowest risk of depression among non-PMH users (p value for interaction = 0.02). Further, carriers of the AA alleles in ESR1 polymorphism RS9340799 had increased prevalence of lifetime major depression only among lifetime PMH users (p = 0.007).

CONCLUSIONS

Our findings support the hypothesis that estrogen receptor polymorphisms influence risk for major depression; the role of estrogen receptors and other sex steroid-related genetic factors may provide unique insights into etiology.

The MAOA, COMT, MTHFR and ESR1 gene polymorphisms are associated with the risk of depression in menopausal women

OBJECTIVE

The aim of the study was assessment of a possible relationship between the polymorphisms of the candidate genes participating in the etiology of some neurological and psychiatric disorders and the risk of depression in perimenopausal and postmenopausal women.

METHODS

A total of 167 (54 perimenopausal and 113 postmenopausal) Caucasian women from western Poland, aged 42-67, were recruited as the patient group in the study because of depressive symptoms, and another 321 healthy women (102 perimenopausal and 219 postmenopausal) served as the controls. All study participants were evaluated for climacteric and depressive disorders according to the Kupperman index and Hamilton rating scale for depression (HRSD), respectively. The following candidate genes were selected for the study: 5HTR2A, 5HTR1B, 5HTR2C, TPH1, TPH2, MAOA, COMT, NET, GABRB1, ESR1, MTHFR, MTR and MTHFD1. In each group the frequencies of the polymorphisms were determined using PCR-RFLP analysis.

RESULTS

After correcting for Bonferroni multiple tests, we found associations between the MAOA c.1460C>T (SNP 1137070), COMT c.472G>A (SNP 4680), MTHFR c.677C>T (SNP 1801133) and ESR1 454(-351) A>G (SNP 9340799) polymorphisms to mild and moderate depressive symptoms in menopausal women. In the perimenopausal and postmenopausal women, genotype association of the MAOA c.1460 CT and c.1460 CT+TT (OR=1.83; pcorr=0.009 and OR=1.85; pcorr=0.003, resp.), and of the MTHFR c.677 TT and c.677 CT+TT (OR=3.52; pcorr=0.00009 and OR=2.06; pcorr=0.0006, resp.), as well as of the COMT c.472 GA and COMT c.472 GA+AA genotypes (OR=2.23; pcorr=0.03 and OR=2.17; pcorr=0.027, resp.) in the postmenopausal women revealed significantly higher frequencies of these variants in depressed female patients than in controls, whereas the ESR1 454(-351) AG and 454(-351) AG+GG genotypes were associated with lower risk of depression in postmenopausal women (OR=0.48; pcorr=0.012, and OR=0.52; pcorr=0.015, resp.).

CONCLUSIONS

Our study substantiates the involvement of the MAOA and MTHFR polymorphisms in climacteric depression and offers evidence that the COMT and ESR1 genes may also play a role in the susceptibility to depressive mood in postmenopausal women.

Perimenopause as a neurological transition state

Perimenopause is a midlife transition state experienced by women that occurs in the context of a fully functioning neurological system and results in reproductive senescence. Although primarily viewed as a reproductive transition, the symptoms of perimenopause are largely neurological in nature. Neurological symptoms that emerge during perimenopause are indicative of disruption in multiple estrogen-regulated systems (including thermoregulation, sleep, circadian rhythms and sensory processing) and affect multiple domains of cognitive function. Estrogen is a master regulator that functions through a network of estrogen receptors to ensure that the brain effectively responds at rapid, intermediate and long timescales to regulate energy metabolism in the brain via coordinated signalling and transcriptional pathways. The estrogen receptor network becomes uncoupled from the bioenergetic system during the perimenopausal transition and, as a corollary, a hypometabolic state associated with neurological dysfunction can develop. For some women, this hypometabolic state might increase the risk of developing neurodegenerative diseases later in life. The perimenopausal transition might also represent a window of opportunity to prevent age-related neurological diseases. This Review considers the importance of neurological symptoms in perimenopause in the context of their relationship to the network of estrogen receptors that control metabolism in the brain.

Association study of the estrogen receptor gene ESR1 with postpartum depression--a pilot study

Perinatal mood disorders, such as postpartum depression (PPD), are costly for society, with potentially serious consequences for mother and child. While multiple genes appear to play a role in PPD susceptibility, the contributions of specific genetic variations remain unclear. Previously implicated as a candidate gene, the estrogen receptor alpha gene (ESR1) is a key player in mediating hormonal differences during pregnancy and the postpartum period. This study addresses genetic factors in perinatal mood disorders, testing nine polymorphisms in ESR1. Two hundred fifty-seven postpartum women were screened for mood disorders, including 52 women with PPD and 32 without any symptoms of mood disorders. We detected a significant association for the upstream TA microsatellite repeat with Edinburgh Postnatal Depression Scale scores (p = 0.007). The same variant was also associated with the occurrence of PPD. Separately, 11 candidate functional polymorphisms in 7 additional genes were genotyped to investigate gene-gene interaction with the ESR1 TA repeat, identifying a potential interaction with the serotonin transporter. Our results support a role for ESR1 in the etiology of PPD, possibly through the modulation of serotonin signaling. Our findings for ESR1 could have broad implications for other disorders and therapies that involve estrogens.

Postpartum depression: psychoneuroimmunological underpinnings and treatment

Postpartum depression (PPD) is common, occurring in 10%-15% of women. Due to concerns about teratogenicity of medications in the suckling infant, the treatment of PPD has often been restricted to psychotherapy. We review here the biological underpinnings to PPD, suggesting a powerful role for the tryptophan catabolites, indoleamine 2,3-dixoygenase, serotonin, and autoimmunity in mediating the consequences of immuno-inflammation and oxidative and nitrosative stress. It is suggested that the increased inflammatory potential, the decreases in endogenous anti-inflammatory compounds together with decreased omega-3 poly-unsaturated fatty acids, in the postnatal period cause an inflammatory environment. The latter may result in the utilization of peripheral inflammatory products, especially kynurenine, in driving the central processes producing postnatal depression. The pharmacological treatment of PPD is placed in this context, and recommendations for more refined and safer treatments are made, including the better utilization of the antidepressant, and the anti-inflammatory and antioxidant effects of melatonin.

Moderation of Breastfeeding Effects on Adult Depression by Estrogen Receptor Gene Polymorphism

Breastfeeding is known to benefit both the mother’s and the child’s health. Our aim was to test the interactive effects between estrogen receptor 1 (ESR1) rs2234693 and breastfeeding when predicting the child’s later depression in adulthood. A sample of 1209 boys and girls from the Young Finns Study were followed from childhood over 27 years up to age 30–45 years. Adulthood depressive symptoms were self-reported by the participants using the Beck Depression Inventory. Breastfeeding as well as several possibly confounding factors was reported by the parents in childhood or adolescence. Breastfeeding tended to predict lower adult depression, while ESR1 rs2234693 was not associated with depression. A significant interaction between breastfeeding and ESR1 was found to predict participants’ depression (P=.004) so that C/C genotype carriers who had not been breastfed had higher risk of depression than T-allele carriers (40.5% versus 13.0%) while there were no genotypic differences among those who had been breastfed. In sex-specific analysis, this interaction was evident only among women. We conclude that child’s genes and maternal behavior may interact in the development of child’s adult depression so that breastfeeding may buffer the inherited depression risk possibly associated with the C/C genotype of the ESR1 gene.