Common variants in FKBP5 gene and major depressive disorder (MDD) susceptibility: a comprehensive meta-analysis

Investigating the relationship between hippocampus/dentate gyrus volume and hypothalamus metabolism in participants with major depressive disorder

Reduced hippocampal volume occurs in major depressive disorder (MDD), potentially due to elevated glucocorticoids from an overactivated hypothalamus-pituitary-adrenal (HPA) axis. To examine this in humans, hippocampal volume and hypothalamus (HPA axis) metabolism was quantified in participants with MDD before and after antidepressant treatment. 65 participants (n = 24 males, n = 41 females) with MDD were treated in a double-blind, randomized clinical trial of escitalopram. Participants received simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) before and after treatment. Linear mixed models examined the relationship between hippocampus/dentate gyrus volume and hypothalamus metabolism. Chi-squared tests and multivariable logistic regression examined the association between hippocampus/dentate gyrus volume change direction and hypothalamus activity change direction with treatment. Multiple linear regression compared these changes between remitter and non-remitter groups. Covariates included age, sex, and treatment type. No significant linear association was found between hippocampus/dentate gyrus volume and hypothalamus metabolism. 62% (38 of 61) of participants experienced a decrease in hypothalamus metabolism, 43% (27 of 63) of participants demonstrated an increase in hippocampus size (51% [32 of 63] for the dentate gyrus) following treatment. No significant association was found between change in hypothalamus activity and change in hippocampus/dentate gyrus volume, and this association did not vary by sex, medication, or remission status. As this multimodal study, in a cohort of participants on standardized treatment, did not find an association between hypothalamus metabolism and hippocampal volume, it supports a more complex pathway between hippocampus neurogenesis and hypothalamus metabolism changes in response to treatment.

The Role of FKBPs in Complex Disorders: Neuropsychiatric Diseases, Cancer, and Type 2 Diabetes Mellitus

Stress is a common denominator of complex disorders and the FK-506 binding protein (FKBP)51 plays a central role in stress. Hence, it is not surprising that multiple studies imply the involvement of the FKBP51 protein and/or its coding gene, FKBP5, in complex disorders. This review summarizes such reports concentrating on three disorder clusters-neuropsychiatric, cancer, and type 2 diabetes mellitus (T2DM). We also attempt to point to potential mechanisms suggested to mediate the effect of FKBP5/FKBP51 on these disorders. Neuropsychiatric diseases considered in this paper include (i) Huntington's disease for which increased autophagic cellular clearance mechanisms related to decreased FKBP51 protein levels or activity is discussed, Alzheimer's disease for which increased FKBP51 activity has been shown to induce Tau phosphorylation and aggregation, and Parkinson's disease in the context of which FKBP12 is mentioned; and (ii) mental disorders, for which significant association with the single nucleotide polymorphism (SNP) rs1360780 of FKBP5 intron 7 along with decreased DNA methylation were revealed. Since cancer is a large group of diseases that can start in almost any organ or tissue of the body, FKBP51's role depends on the tissue type and differences among pathways expressed in those tumors. The FKBP51-heat-shock protein-(Hsp)90-p23 super-chaperone complex might function as an oncogene or as a tumor suppressor by downregulating the serine/threonine protein kinase (AKt) pathway. In T2DM, two potential pathways for the involvement of FKBP51 are highlighted as affecting the pathogenesis of the disease-the peroxisome proliferator-activated receptor-γ (PPARγ) and AKt.

The digestion and dietary carbohydrate pathway contains 100% gene mutations enrichment among 117 patients with major depressive disorder

Introduction

Major depressive disorder (MDD) is partially inheritable while its mechanism is still uncertain.

Methods

This cross-sectional study focused on gene pathways as a whole rather than polymorphisms of single genes. Deep sequencing and gene enrichment analysis based on pathways in Reactome database were obtained to reveal gene mutations.

Results

A total of 117 patients with MDD and 78 healthy controls were enrolled. The Digestion and Dietary Carbohydrate pathway (Carbohydrate pathway) was determined to contain 100% mutations in patients with MDD and 0 mutation in matched healthy controls.

Discussion

Findings revealed in the current study enable a better understanding of gene pathways mutations status in MDD patients, indicating a possible genetic mechanism of MDD development and a potential diagnostic or therapeutic target.

Role of FKBP5 and its genetic mutations in stress-induced psychiatric disorders: an opportunity for drug discovery

Stress-induced mental health disorders are affecting many people around the world. However, effective drug therapy for curing psychiatric diseases does not occur sufficiently. Many neurotransmitters, hormones, and mechanisms are essential in regulating the body's stress response. One of the most critical components of the stress response system is the hypothalamus-pituitary-adrenal (HPA) axis. The FKBP prolyl isomerase 51 (FKBP51) protein is one of the main negative regulators of the HPA axis. FKBP51 negatively regulates the cortisol effects (the end product of the HPA axis) by inhibiting the interaction between glucocorticoid receptors (GRs) and cortisol, causing reduced transcription of downstream cortisol molecules. By regulating cortisol effects, the FKBP51 protein can indirectly regulate the sensitivity of the HPA axis to stressors. Previous studies have indicated the influence of FKBP5 gene mutations and epigenetic changes in different psychiatric diseases and drug responses and recommended the FKBP51 protein as a drug target and a biomarker for psychological disorders. In this review, we attempted to discuss the effects of the FKBP5 gene, its mutations on different psychiatric diseases, and drugs affecting the FKBP5 gene.

Gender Differences in Cortisol and Cortisol Receptors in Depression: A Narrative Review

Stress is known to have a significant impact on mental health. While gender differences can be found in stress response and mental disorders, there are limited studies on the neuronal mechanisms of gender differences in mental health. Here, we discuss gender and cortisol in depression as presented by recent clinical studies, as well as gender differences in the role of glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs) in stress-associated mental disorders. When examining clinical studies drawn from PubMed/MEDLINE (National Library of Medicine) and EMBASE, salivary cortisol generally showed no gender correlation. However, young males were reported to show heightened cortisol reactivity compared to females of similar age in depression. Pubertal hormones, age, early life stressors, and types of bio-samples for cortisol measurement affected the recorded cortisol levels. The role of GRs and MRs in the HPA axis could be different between males and females during depression, with increased HPA activity and upregulated MR expression in male mice, while the inverse happened in female mice. The functional heterogeneity and imbalance of GRs and MRs in the brain may explain gender differences in mental disorders. This knowledge and understanding will support the development of gender-specific diagnostic markers involving GRs and MRs in depression.

Investigating The Relationship Between Hippocampus:Dentate Gyrus Volume and Hypothalamus Metabolism in Participants with Major Depressive Disorder

Reduced hippocampal volume occurs in major depressive disorder (MDD), theoretically due to elevated glucocorticoids from an overactivated hypothalamus-pituitary-adrenal (HPA) axis. To examine this in humans, hippocampal volume, and hypothalamus (HPA axis) metabolism was quantified in participants with MDD before and after antidepressant treatment. 65 participants (n = 24 males, n = 41 females) with MDD were treated in a double-blind, randomized clinical trial of escitalopram. Participants received simultaneous positron emission tomography (PET) / magnetic resonance imaging (MRI) before and after treatment. Linear mixed models examined the relationship between hippocampus/dentate gyrus volume and hypothalamus metabolism. Chi-squared tests and multivariable logistic regression examined the association between hippocampus/dentate gyrus volume change direction and hypothalamus activity change direction with treatment. Multiple linear regression compared these changes between remitter and non-remitter groups. Covariates included age, sex, and treatment type. No significant linear association was found between hippocampus/dentate gyrus volume and hypothalamus metabolism. 62% (38 of 61) of participants experienced a decrease in hypothalamus metabolism, 43% (27 of 63) of participants demonstrated an increase in hippocampus size (51% [32 of 63] for the dentate gyrus) following treatment. No significant association was found between change in hypothalamus activity and change in hippocampus/dentate gyrus volume, and this association did not vary by sex, medication, or remission status. As this multimodal study, in a cohort of participants on standardized treatment, did not find an association between hypothalamus metabolism and hippocampal volume, it supports a more complex pathway between hippocampus neurogenesis and treatment response.

Precision Medicine Approaches to Mental Health Care

Developing a more comprehensive understanding of the physiological underpinnings of mental illness, precision medicine has the potential to revolutionize psychiatric care. With recent breakthroughs in next-generation multi-omics technologies and data analytics, it is becoming more feasible to leverage multimodal biomarkers, from genetic variants to neuroimaging biomarkers, to objectify diagnostics and treatment decisions in psychiatry and improve patient outcomes. Ongoing work in precision psychiatry will parallel progress in precision oncology and cardiology to develop an expanded suite of blood- and neuroimaging-based diagnostic tests, empower monitoring of treatment efficacy over time, and reduce patient exposure to ineffective treatments. The emerging model of precision psychiatry has the potential to mitigate some of psychiatry's most pressing issues, including improving disease classification, lengthy treatment duration, and suboptimal treatment outcomes. This narrative-style review summarizes some of the emerging breakthroughs and recurring challenges in the application of precision medicine approaches to mental health care.

Circulating FK506 binding protein 51 mRNA expression in patients with pituitary adenomas

Background

FK506 binding protein 51 (FKBP5) is a co-chaperone regulator of the glucocorticoid receptor (GR). Recent studies have reported increased FKBP5 mRNA in the circulation from patients with Cushing disease (CD) which returned to comparable levels seen in healthy controls following successful trans-nasal trans-sphenoidal (TNTS) surgical corticotroph tumor removal. However, the expression of circulating FKBP5 mRNA levels in other pituitary tumor subtypes and its specificity to corticotroph tumors is unknown.

Methods

Pre-operative blood was collected from consecutive patients undergoing TNTS for pituitary tumors (n = 57) at our center between 2015 and 2019. Total RNA was isolated from whole blood using RiboPure blood RNA isolation kit and real-time qPCR was used to quantitate circulating FKBP5 mRNA expression.

Results

Consistent with the prior report, higher circulating FKBP5 mRNA levels were observed in 20 patients with CD prior to surgical tumor removal, compared to 21 healthy controls (p < 0.0005) and compared to 8 patients harboring gonadotroph pituitary tumors (p < 0.05) and 6 patients with silent corticotroph pituitary tumors (p < 0.05). However, circulating FKBP5 mRNA levels were higher in 10 patients with prolactin (PRL)-secreting pituitary tumors compared to healthy controls (p < 0.05), and did not differ between patients with CD and patients with growth hormone secreting tumors (GH-omas).

Conclusions

Although we confirm that circulating FKBP5 mRNA is higher in patients with corticotroph tumors compared to healthy subjects, measurement of circulating FKBP5 does not appear to be helpful to distinguish corticotroph tumors from other pituitary tumor sub-types.

A Genomic Study of the Japanese Population Focusing on the Glucocorticoid Receptor Interactome Highlights Distinct Genetic Characteristics Associated with Stress Response

All living organisms have been programmed to maintain a complex inner equilibrium called homeostasis, despite numerous adversities during their lifespan. Any threatening or perceived as such stimuli for homeostasis is termed a stressor, and a highly conserved response system called the stress response system has been developed to cope with these stimuli and maintain or reinstate homeostasis. The glucocorticoid receptor, a transcription factor belonging to the nuclear receptors protein superfamily, has a major role in the stress response system, and research on its interactome may provide novel information regarding the mechanisms underlying homeostasis maintenance. A list of 149 autosomal genes that have an essential role in GR function or are prime examples of GRE-containing genes was composed in order to gain a comprehensive view of the GR interactome. A search for SNPs on those particular genes was conducted on a dataset of 3554 Japanese individuals, with mentioned polymorphisms being annotated with relevant information from the ClinVar, LitVar, and dbSNP databases. Forty-two SNPs of interest and their genomic locations were identified. These SNPs have been associated with drug metabolism and neuropsychiatric, metabolic, and immune system disorders, while most of them were located in intronic regions. The frequencies of those SNPs were later compared with a dataset consisting of 1465 Korean individuals in order to find population-specific characteristics based on some of the identified SNPs of interest. The results highlighted.that rs1043618 frequencies were different in the two populations, with mentioned polymorphism having a potential role in chronic obstructive pulmonary disease in response to environmental stressors. This SNP is located in the HSPA1A gene, which codes for an essential GR co-chaperone, and such information showcases that similar gene may be novel genomic targets for managing or combatting stress-related pathologies.

Burning down the house: reinventing drug discovery in psychiatry for the development of targeted therapies

Despite advances in neuroscience, limited progress has been made in developing new and better medications for psychiatric disorders. Available treatments in psychiatry rely on a few classes of drugs that have a broad spectrum of activity across disorders with limited understanding of mechanism of action. While the added value of more targeted therapies is apparent, a dearth of pathophysiologic mechanisms exists to support targeted treatments, and where mechanisms have been identified and drugs developed, results have been disappointing. Based on serendipity and early successes that led to the current drug armamentarium, a haunting legacy endures that new drugs should align with outdated and overinclusive diagnostic categories, consistent with the idea that "one size fits all". This legacy has fostered clinical trial designs focused on heterogenous populations of patients with a single diagnosis and non-specific outcome variables. Disturbingly, this approach likely contributed to missed opportunities for drugs targeting the hypothalamic-pituitary-adrenal axis and now inflammation. Indeed, cause-and-effect data support the role of inflammatory processes in neurotransmitter alterations that disrupt specific neurocircuits and related behaviors. This pathway to pathology occurs across disorders and warrants clinical trial designs that enrich for patients with increased inflammation and use primary outcome variables associated with specific effects of inflammation on brain and behavior. Nevertheless, such trial designs have not been routinely employed, and results of anti-inflammatory treatments have been underwhelming. Thus, to accelerate development of targeted therapeutics including in the area of inflammation, regulatory agencies and the pharmaceutical industry must embrace treatments and trials focused on pathophysiologic pathways that impact specific symptom domains in subsets of patients, agnostic to diagnosis. Moreover, closer collaboration among basic and clinical investigators is needed to apply neuroscience knowledge to reveal disease mechanisms that drive psychiatric symptoms. Together, these efforts will support targeted treatments, ultimately leading to new and better therapeutics in psychiatry.

The association of FKBP5 polymorphisms with the severity of depressive disorder in patients with methamphetamine use disorders

Background

Co-occurring depressive disorder (DD) in patients of methamphetamine use disorder (MAUD) impacts the diagnosis, treatment, and prognosis of the disease. Although FKBP5 has been associated with a variety of psychiatric disorders, whether FKBP5 influences depression susceptibility in MAUD is unknown so far.

Methods

Here, we sequenced six FKBP5 single-nucleotide polymorphism (SNP) sites (rs4713916, rs6926133, rs9470080, rs737054, rs4713902, and rs9470079) in 282 methamphetamine users. MAUD and DD were evaluated by clinical questionnaires. SPSS was used to analyze the relationship between FKBP5 SNPs and DD in individuals with MAUD.

Results

Of the 282 methamphetamine users, 161 individuals met the MAUD criteria, and among them, 50 patients (31.1%) had DD co-occurring. Importantly, the incidence of DD in individuals with MAUD was 3.314 times greater than that of the methamphetamine users who did not meet the MAUD criteria (p < 0.001). Although none of the six SNPs of FKBP5 were correlated with the co-occurrence of DD in the population with MAUD, two FKBP5 alleles (rs4713916A and rs6926133A) were substantially associated with the higher DD scores in patients with MAUD (p < 0.05). Moreover, those with the two risk alleles do not have much higher scores than those with a single risk allele, and the strong linkage disequilibrium of the two SNPs may be the underlying cause of this result. Despite having weak linkage disequilibrium with either rs4713916 or rs6926133, FKBP5 rs9470079 became risky when paired with either.

Conclusion

The results of this study revealed that the FKBP5 risk alleles (rs4713916A and rs6926133A) were associated with a greater probability of severe DD in patients with MAUD. These findings here would help with the development of biological early warning markers and the creation of personalized treatment strategies for MAUD.

Psycho-cognitive assessment and quality of life in older adults with chronic obstructive pulmonary disease-carrying the rs4713916 gene polymorphism (G/A) of gene FKBP5 and response to pulmonary rehabilitation: a proof of concept study

PURPOSE

Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary and extra-pulmonary multi-morbidity including depression, anxiety and cognitive disorders. Several studies investigated the association of the FKBP5 gene polymorphisms with susceptibility to anxiety, depression, and behavioral disorders. The FKBP5 gene codifies the FKBP51 protein which modulates the glucocorticoid receptor in the adaptive stress response. Genetic variants of the FKBP5 gene have been associated to a higher risk of developing mental disorders. We analyzed the association of genetic variants and stress exposure investigating the susceptibility to psychological distress and the impact on cognitive balance and quality of life (QoL) of COPD patients carrying the rs4713916 polymorphism (G/A) and we examined its association, with COPD rehabilitative outcomes.

MATERIALS AND METHODS

A pilot study evaluated cognitive, psychological, clinical alterations/disorders, QoL, and coping strategies in 70 older adults with COPD, undergoing pulmonary rehabilitation, stratified according to the FKBP5 rs4713916 genotype (GG or GA).

RESULTS

Carriers of rs4713916 polymorphisms (G/A) show better cognitive performances, a higher degree of independence in the daily living activities, better QoL, no presence of depressive mood and anxiety symptoms, no family history of psychiatric disorders, more ability to cope with stressors by avoiding emotions but demanding emotional support, and lesser use of anti-anxiety, anti-depressant, anti-psychotic, hypnotic-sedative drugs. No difference was found in the number of comorbidities.

CONCLUSION

These results offer valuable insights into the role of FKBP5 in the complex network of mechanisms associated to clinical, psychological and behavioral features of COPD patients.

The Interactive Effect of Genetic and Epigenetic Variations in FKBP5 and ApoE Genes on Anxiety and Brain EEG Parameters

FKBP51 is a key stress-responsive regulator of the hypothalamic–pituitary–adrenal axis. To elucidate the contribution of rs1360780 FKBP5 C/T alleles to aging and longevity, we genotyped FKBP5 in a cohort of 800 non-demented and Alzheimer’s disease (AD) subjects of different age, taking into account the allele state of ApoE ε4, the major risk factor for AD. Furthermore, we searched for the association of FKBP5 with subcohorts of non-demented subjects evaluated for anxiety and resting-state quantitative EEG characteristics, associated with cognitive, emotional, and functional brain activities. We observed that increased state anxiety scores depend on the combination of the FKBP5 and ApoE genotypes and on the DNA methylation state of the FKBP5 promoter and ApoE genotype. We also found a significant gender-dependent correlation between FKBP5 promoter methylation and alpha-, delta-, and theta-rhythms. Analysis of the FKBP5 expression in an independent cohort revealed a significant upregulation of FKBP5 in females versus males. Our data suggest a synergistic effect of the stress-associated (FKBP5) and neurodegeneration-associated (ApoE) gene alleles on anxiety and the gender-dependent effect of FKBP5 on neurophysiological brain activity.

Regulatory functions of FKBP5 intronic regions associated with psychiatric disorders

The FKBP5 gene codifies a co-chaperone protein associated with the modulation of glucocorticoid receptor interaction involved in the adaptive stress response. The FKBP5 intracellular concentration affects the binding affinity of the glucocorticoid receptor (GR) to glucocorticoids (GCs). This gene has glucocorticoid response elements (GREs) located in introns 2, 5 and 7, which affect its expression. Recent studies have examined GRE activity and the effects of genetic variants on transcript efficiency and their contribution to susceptibility to behavioral disorders. Epigenetic changes and environmental factors can influence the effects of these allele-specific variants, impacting the response to GCs of the FKBP5 gene. The main epigenetic mark investigated in FKBP5 intronic regions is DNA methylation, however, few studies have been performed for all GREs located in these regions. One of the major findings was the association of low DNA methylation levels in the intron 7 of FKBP5 in patients with psychiatric disorders. To date, there are no reports of DNA methylation in introns 2 and 5 of the gene associated with diagnoses of psychiatric disorders. This review highlights what has been discovered so far about the relationship between polymorphisms and epigenetic targets in intragenic regions, and reveals the gaps that need to be explored, mainly concerning the role of DNA methylation in these regions and how it acts in psychiatric disease susceptibility.

Hypothalamus volume and DNA methylation of stress axis genes in major depressive disorder: A CAN-BIND study report

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis is considered one of the mechanisms underlying the development of major depressive disorder (MDD), but the exact nature of this dysfunction is unknown. We investigated the relationship between hypothalamus volume (HV) and blood-derived DNA methylation in MDD. We obtained brain MRI, clinical and molecular data from 181 unmedicated MDD and 90 healthy control (HC) participants. MDD participants received a 16-week standardized antidepressant treatment protocol, as part of the first Canadian Biomarker Integration Network in Depression (CAN-BIND) study. We collected bilateral HV measures via manual segmentation by two independent raters. DNA methylation and RNA sequencing were performed for three key HPA axis-regulating genes coding for the corticotropin-binding protein (CRHBP), glucocorticoid receptor (NR3C1) and FK506 binding protein 5 (FKBP5). We used elastic net regression to perform variable selection and assess predictive ability of methylation variables on HV. Left HV was negatively associated with duration of current episode (ρ = -0.17, p = 0.035). We did not observe significant differences in HV between MDD and HC or any associations between HV and treatment response at weeks 8 or 16, overall depression severity, illness duration or childhood maltreatment. We also did not observe any differentially methylated CpG sites between MDD and HC groups. After assessing functionality by correlating methylation levels with RNA expression of the respective genes, we observed that the number of functionally relevant CpG sites differed between MDD and HC groups in FKBP5 (χ² = 77.25, p < 0.0001) and NR3C1 (χ² = 7.29, p = 0.007). Cross-referencing functionally relevant CpG sites to those that were highly ranked in predicting HV in elastic net modeling identified one site from FKBP5 (cg03591753) and one from NR3C1 (cg20728768) within the MDD group. Stronger associations between DNA methylation, gene expression and HV in MDD suggest a novel putative molecular pathway of stress-related sensitivity in depression. Future studies should consider utilizing the epigenome and ultra-high field MR data which would allow the investigation of HV sub-fields.

Stress-Responsive Gene FK506-Binding Protein 51 Mediates Alcohol-Induced Liver Injury Through the Hippo Pathway and Chemokine (C-X-C Motif) Ligand 1 Signaling

BACKGROUND AND AIMS

Chronic alcohol drinking is a major risk factor for alcohol-associated liver disease (ALD). FK506-binding protein 51 (FKBP5), a cochaperone protein, is involved in many key regulatory pathways. It is known to be involved in stress-related disorders, but there are no reports regarding its role in ALD. This present study aimed to examine the molecular mechanism of FKBP5 in ALD.

APPROACH AND RESULTS

We found a significant increase in hepatic FKBP5 transcripts and protein expression in patients with ALD and mice fed with chronic-plus-single binge ethanol. Loss of Fkbp5 in mice protected against alcohol-induced hepatic steatosis and inflammation. Transcriptomic analysis revealed a significant reduction of Transcriptional enhancer factor TEF-1 (TEA) domain transcription factor 1 (Tead1) and chemokine (C-X-C motif) ligand 1 (Cxcl1) mRNA in ethanol-fed Fkbp5-/- mice. Ethanol-induced Fkbp5 expression was secondary to down-regulation of methylation level at its 5' untranslated promoter region. The increase in Fkbp5 expression led to induction in transcription factor TEAD1 through Hippo signaling pathway. Fkbp5 can interact with yes-associated protein (YAP) upstream kinase, mammalian Ste20-like kinase 1 (MST1), affecting its ability to phosphorylate YAP and the inhibitory effect of hepatic YAP phosphorylation by ethanol leading to YAP nuclear translocation and TEAD1 activation. Activation of TEAD1 led to increased expression of its target, CXCL1, a chemokine-mediated neutrophil recruitment, causing hepatic inflammation and neutrophil infiltration in our mouse model.

CONCLUSIONS

We identified an FKBP5-YAP-TEAD1-CXCL1 axis in the pathogenesis of ALD. Loss of FKBP5 ameliorates alcohol-induced liver injury through the Hippo pathway and CXCL1 signaling, suggesting its potential role as a target for the treatment of ALD.

Stressful social environment and financial strain drive depressive symptoms, and reveal the effects of a FKBP5 variant and male sex, in African Americans living in Tallahassee

OBJECTIVES

The World Health Organization estimates that almost 300 million people suffer from depression worldwide. African Americans are understudied for depression-related phenotypes despite widespread racial disparities. In our study of African Americans, we integrated information on psychosocial stressors with genetic variation in order to better understand how these factors associated with depressive symptoms.

METHODS

Our research strategy combined information on financial strain and social networks with genetic data to investigate variation in symptoms of depression (CES-D scores). We collected self-report data on depressive symptoms, financial strain (difficulty paying bills) and personal social networks (a model of an individual's social environment), and we genotyped genetic variants in five genes previously implicated in depressive disorders (HTR1a, BDNF, GNB3, SLC6A4, and FKBP5) in 128 African Americans residing in Tallahassee, Florida. We tested for direct and gene-environment interactive effects of the psychosocial stressors and genetic variants on depressive symptoms.

RESULTS

Significant associations were identified between high CES-D scores and a stressful social environment (i.e., a high percentage of people in participants' social network who were a source of stress) and high financial strain. Only one genetic variant (rs1360780 in FKBP5) was significantly associated with CES-D scores and only when psychosocial stressors were included in the model; the T allele had an additive effect on depressive symptoms. Sex was also significantly associated with CES-D score in the model with psychosocial stressors and genetic variants; males had higher CES-D scores. No significant interactive effects were detected.

CONCLUSIONS

A stressful social environment and material disadvantage increase depressive symptoms in the study population. Additional associations with FKBP5 and male sex were revealed in models that included both psychosocial and genetic data. Our results suggest that incorporating psychosocial stressors may empower future genetic association studies and help clarify the biological consequences of social and financial stress.

The association of FKBP5 polymorphism with asthma susceptibility in asthmatic patients

OBJECTIVES

Inhaled corticosteroids are the most effective controllers of asthma, although asthmatics vary in their response. FKBP51 is a major component of the glucocorticoid receptor which regulates its responses to corticosteroids. Therefore, the present study aims to identify the role of FKBP5 gene polymorphism in asthma susceptibility and corticosteroid resistance.

METHODS

DNA was extracted from the blood of 68 asthmatic and 40 control subjects. FKBP5 gene fragments were amplified by PCR and sequenced by the Sanger method. The sequencing results were aligned by mapping on the reference sequences of National center of Biotechnology Information (NCBI) and single nucleotide polymorphisms (SNPs) which were checked. Finally, the genotype, allele frequency and odds ratio (OR) were calculated.

RESULTS

The FKBP5 fragment sequencing revealed the presence of rs1360780 and one novel SNP found in 17 samples taken from asthmatic patients as compared to db SNP data in the NCBI database. The FKBP5 variant (rs1360780) indicated that the allele frequency of risk allele T was 41.18% in patients and 20% in control group members p<0.001 and OR=2.8 when compared to a wild C allele frequency of 58.82% in patients and 64% in the control group members. The novel SNP FKBP5 was compared to the SNP database in the NCBI database in which wild T allele was substituted with G. The novel SNP was submitted to the ClinVar Submission Portal at NCBI with accession number: rs1581842283 and confirmed an asthma susceptibility risk factor with allele G frequency of 11.76% in asthmatics and 2.5% in the control group members (OR=5.2, p<0.05), as compared to a wild T allele frequency of 88.24% in asthmatics and 97.5% in the control group members.

CONCLUSIONS

The risk allele T of rs1360780 and the novel SNP rs1581842283 risk allele G predict asthma susceptibility but show no association with corticosteroid resistant.

A large-scale genome-wide gene expression analysis in peripheral blood identifies very few differentially expressed genes related to antidepressant treatment and response in patients with major depressive disorder

A better understanding of the biological factors underlying antidepressant treatment in patients with major depressive disorder (MDD) is needed. We perform gene expression analyses and explore sources of variability in peripheral blood related to antidepressant treatment and treatment response in patients suffering from recurrent MDD at baseline and after 8 weeks of treatment. The study includes 281 patients, which were randomized to 8 weeks of treatment with vortioxetine (N = 184) or placebo (N = 97). To our knowledge, this is the largest dataset including both gene expression in blood and placebo-controlled treatment response measured by a clinical scale in a randomized clinical trial. We identified three novel genes whose RNA expression levels at baseline and week 8 are significantly (FDR < 0.05) associated with treatment response after 8 weeks of treatment. Among these genes were SOCS3 (FDR = 0.0039) and PROK2 (FDR = 0.0028), which have previously both been linked to depression. Downregulation of these genes was associated with poorer treatment response. We did not identify any genes that were differentially expressed between placebo and vortioxetine groups at week 8 or between baseline and week 8 of treatment. Nor did we replicate any genes identified in previous peripheral blood gene expression studies examining treatment response. Analysis of genome-wide expression variability showed that type of treatment and treatment response explains very little of the variance, a median of <0.0001% and 0.05% in gene expression across all genes, respectively. Given the relatively large size of the study, the limited findings suggest that peripheral blood gene expression might not be the best approach to explore the biological factors underlying antidepressant treatment.

Application of a diathesis-stress model to the interplay of cortical structural development and emerging depression in youth

Cross-sectional studies in adults have long identified differences in cortical structure in adults with depression compared to healthy adults, with most studies identifying reductions in grey matter volume, cortical thickness, and surface area in primarily frontal cortical regions including the OFC, ACC, and variable sub-regions of the PFC. However, when, why, and for whom these neural correlates of depression emerge remains poorly understood, necessitating developmental study of associations between depression and cortical structure. We systematically reviewed studies examining these associations in child/adolescent samples, and applied a developmentally-focused diathesis-stress model to understand the impacts of depressogenic risk-factors and stressors on the development of structural neural correlates of depression. Cross-sectional findings in youth are generally similar to those found in adults, but vary in magnitude and direction of effects. Preliminary evidence suggests that age, sex, severity, and comorbidity moderate these associations. Longitudinal studies show depression prospectively predicting cortical structure and structure predicting emerging depression. Consistent with a diathesis-stress model, associations have been noted between risk-factors for depression (e.g., genetic risk, family risk) and environmental stressors (e.g., early life stress) and structural neural correlates. Further investigation of these associations across development with attention to vulnerability factors and stressors is indicated.

Association of FKBP5 genotype with depressive symptoms in patients with coronary heart disease: a prospective study

Depression and coronary heart disease (CHD) are prevalent and often co-occurring disorders. Both have been associated with a dysregulated stress system. As a central element of the stress system, the FKBP5 gene has been shown to be associated with depression. In a prospective design, this study aims to investigate the association of FKBP5 with depressive symptoms in CHD patients. N = 268 hospitalized CHD patients were included. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale (HADS-D) at four time points (baseline, and after 1 month, 6 months, and 12 months). The functional FKBP5 single-nucleotide polymorphism (SNP) rs1360780 was selected for genotyping. Linear regression models showed that a higher number of FKBP5 C alleles was associated with more depressive symptoms in CHD patients both at baseline (p = 0.015) and at 12-months follow-up (p = 0.025) after adjustment for confounders. Further analyses revealed that this effect was driven by an interaction of FKBP5 genotype with patients’ prior CHD course. Specifically, only in patients with a prior myocardial infarction or coronary revascularization, more depressive symptoms were associated with a higher number of C alleles (baseline: p = 0.046; 1-month: p = 0.026; 6-months: p = 0.028). Moreover, a higher number of C alleles was significantly related to a greater risk for dyslipidemia (p = .016). Our results point to a relevance of FKBP5 in the association of the two stress-related diseases depression and CHD.

Impacts of FKBP5 variants on large-scale brain network connectivity in healthy adults

BACKGROUND

FK506 binding protein 5 (FKBP5) rs1360780 polymorphism has been identified as a molecular genetic marker associated with the dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. The impact of FKBP5 rs1360780 on the large-scale brain network connectivity in healthy adults is still unknown.

METHODS

479 healthy volunteers (age: 20-80years) completed MRI scans, neuropsychological assessments and blood analysis.All subjects were divided into CC, CT and TT genotypes. Within and between network connectivities (10 sub-networks) were calculated using resting state functional MRI (rs-fMRI) data. The genetic effects and gene-gender/age interaction on large-scale network connectivity were explored.

RESULTS

Compared with CC and CT groups, TT group showed increased intra-connectivity in default mode network (DMN) and increased inter-connectivity mainly distributed among the network of DMN, salience network (SAN), dorsal attention network (DAN), ventral attention network (VAN), subcortical network (SUB), and visual network (VIS). Gene-by-gender and gene-by-age interaction were found in inter-connectivity of DAN to VIS and DMN to FPN, respectively. The altered connectivities correlated with anxiety status test score.

LIMITATIONS

Plasma adrenocorticotropic hormone (ACTH) or cortisol were not measured,or else, we could estimate the hypothalamic-pituitary-adrenal (HPA) axis activity which may strengthen our results.

CONCLUSIONS

FKBP5 rs1360780 modulates the large-scale brain network connectivity in healthy adults. TT carriers showed the increased intra- and inter-connectivities mainly distributed among the network of DMN, SAN, DAN, VAN, SUB and VIS.

No association between FKBP5 gene methylation and acute and long-term cortisol output

Prior studies identified DNA methylation (DNA_M) changes in a regulatory region within the FK506 binding protein 5 (FKBP5) gene as a crucial mediator of long-term negative health outcomes following early adversity. A critical mechanism underlying this link, in turn, has been suggested to be epigenetically induced dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study was thus to investigate associations of FKBP5 DNA_M with both acute and chronic cortisol output. Two hundred adults with differential exposure to childhood trauma (CT) were underwent a laboratory stressor (Trier Social Stress Test) and provided salivary samples for the analysis of acute cortisol stress responses. In addition, hair cortisol concentrations were determined as a valid measure of integrated long-term cortisol levels. Whole blood samples were drawn for DNA_M analyses of FKBP5 intron 7 via bisulfite pyrosequencing. In contrast to most prior work, only healthy participants were included in order to disentangle the effects of trauma exposure per se from those related to mental disorders. First, our findings did not reveal strong evidence for a robust effect of CT on FKBP5 intron 7 DNA_M status, even if genetic predisposition (rs1360780 genotype) was taken into account. Second, FKBP5 DNA_M levels were found to be unrelated to acute cortisol stress reactivity and long-term cortisol concentration in hair. The failure to demonstrate a significant association between CT and FKBP5 DNA_M in an exclusively healthy sample could be interpreted as suggesting that individuals' mental health status may be a critical modulator of previously observed effects.

Low Circulating Levels of GR, FKBP5, and SGK1 in Medicated Patients With Depression Are Not Altered by Electroconvulsive Therapy

OBJECTIVES

Hypothalamic-pituitary-adrenal axis dysregulation is frequently observed in patients with depression, with increased levels of the glucocorticoid (GC) cortisol commonly reported. Hypothalamic-pituitary-adrenal axis dysregulation may be a consequence of impaired feedback inhibition due to GC receptor (GR) impairments or dysfunction, termed "glucocorticoid resistance." Here, our objective was to assess mRNA levels of GC-related markers (GR, FKBP5, serum glucocorticoid kinase 1 [SGK1]) in patients with depression versus controls and in patient samples after electroconvulsive therapy (ECT). We also examined the relationship between these GC-related markers and 24-item Hamilton Depression Rating Scale (HAM-D24) scores to assess the utility of using them as biological markers for depression or the therapeutic response to ECT.

METHODS

GR, FKBP5, and SGK1 mRNA levels were examined in whole blood samples from 88 medicated patients with depression pre-/post-ECT and 63 controls using quantitative real-time polymerase chain reaction. Exploratory subgroup correlational analyses were performed to determine the relationship between GR, FKBP5, and SGK1 and 24-item Hamilton Depression Rating Scale scores.

RESULTS

GR, FKBP5, and SGK1 mRNA levels were significantly lower in medicated patients with depression compared with controls (P < 0.001, P = 0.03, P < 0.001, respectively), but ECT did not alter their levels (all P > 0.05). There was no relationship between GR, FKBP5, or SGK1 and 24-item Hamilton Depression Rating Scale scores.

CONCLUSIONS

GR, FKBP5, and SGK1 do not seem to be involved in the peripheral molecular response to ECT and do not represent useful biomarkers for predicting the therapeutic response to ECT in a real-world clinical setting.

Genetic variants associated with psychotic symptoms across psychiatric disorders

BACKGROUND

Recent evidence suggests that psychiatric symptoms share a common genetic liability across diagnostic categories. The present study investigated the effects of variants within previously identified relevant genes on specific symptom clusters, independently from the diagnosis.

METHODS

1550 subjects affected by Schizophrenia (SCZ), Major Depressive Disorder or Bipolar Disorder were included. Symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depression Rating Scale (HDRS). Principal component analysis and a further clinical refinement were used to define symptom clusters. Clusters scores were tested for association with 46 genetic variants within nine genes previously linked to one or more major psychiatric disorders by large genome wide association studies (ANK3, CACNA1C, CACNB2, FKBP5, FZD3, GRM7, ITIH3, SYNE1, TCF4). Exploratory analyses were performed in each disorder separately to further elucidate the SNPs effects.

RESULTS

five PANSS clusters (Negative; Impulsiveness; Cognitive; Psychotic; Depressive) and four HDRS clusters (Core Depressive; Somatic; Psychotic-like; Insomnia) were identified. CACNA1C rs11615998 was associated with HDRS Psychotic cluster in the whole sample. In the SCZ sample, CACNA1C rs11062296 was associated with PANSS Impulsiveness cluster and CACNA1C rs2238062 was associated with PANSS negative cluster.

DISCUSSION

CACNA1C rs11615998 was associated with psychotic symptoms (C-allele carriers have decreased psychotic-risk) independently from the diagnosis, in line with the evidence of a cross disorder effect of many risk variants. This gene was previously associated with SCZ and cross-disorder liability to psychiatric disorders. Our findings confirmed that deep phenotyping is pivotal to clarify the role of genetic variants on symptoms patterns.

Genes Involved in the HPA Axis and the Symptom Cluster of Fatigue, Depressive Symptoms, and Anxiety in Women With Breast Cancer During 18 Months of Adjuvant Therapy

This study aimed to (1) identify subgroups of women with breast cancer with the psychological symptom cluster (fatigue, depressive symptoms, and anxiety) during the first 18 months of adjuvant therapy and (2) explore associations between demographic and clinical characteristics and variations in genetic polymorphisms related to hypothalamic-pituitary-adrenal (HPA) axis function and predicted symptom trajectory subgroup membership. We obtained symptom data at 4 time points from baseline to 18 months of adjuvant therapy among 292 postmenopausal women with breast cancer. Genetic data were collected in a subgroup at baseline (N = 184). Group-based multitrajectory modeling was used to classify women into subgroups with similar psychological symptom cluster trajectories. Binary logistic regression was used to explore the associations between each genotypic and phenotypic predictor and predicted subgroup membership. Two distinct symptom subgroups (low and high) were identified based on the trajectories of the symptom cluster of fatigue, depressive symptoms, and anxiety over the first 18 months of adjuvant therapy. Women who were younger, less educated, and who received chemotherapy had greater likelihood of being in the high-symptom subgroup. Variation in genes regulating the HPA axis (FKBP5 rs9394309 [odds ratio (OR) = 3.98, p = .015], NR3C2 rs5525 [OR = 2.54, p = .036], and CRHR1 rs12944712 [OR = 3.99, p = .021]) was associated with membership in the high-symptom subgroup. These results may help to identify women with breast cancer who are at increased risk for psychological symptoms, facilitating the development of individualized and preemptive interventions to better manage these symptoms during adjuvant therapy.

Role of glucocorticoid- and monoamine-metabolizing enzymes in stress-related psychopathological processes

Glucocorticoid signaling is fundamental in healthy stress coping and in the pathophysiology of stress-related diseases, such as post-traumatic stress disorder (PTSD). Glucocorticoids are metabolized by cytochrome P450 (CYP) as well as 11-β-hydroxysteroid dehydrogenase type 1 (11βHSD1) and 2 (11βHSD2). Acute stress-induced increase in glucocorticoid concentrations stimulates the expression of several CYP sub-types. CYP is primarily responsible for glucocorticoid metabolism and its increased activity can result in decreased circulating glucocorticoids in response to repeated stress stimuli. In addition, repeated stress-induced glucocorticoid release can promote 11βHSD1 activation and 11βHSD2 inhibition, and the 11βHSD2 suppression can lead to apparent mineralocorticoid excess. The activation of CYP and 11βHSD1 and the suppression of 11βHSD2 may at least partly contribute to development of the blunted glucocorticoid response to stressors characteristic in high trait anxiety, PTSD, and other stress-related disorders. Glucocorticoids and glucocorticoid-metabolizing enzymes interact closely with other biomolecules such as inflammatory cytokines, monoamines, and some monoamine-metabolizing enzymes, namely the monoamine oxidase type A (MAO-A) and B (MAO-B). Glucocorticoids boost MAO activity and this decreases monoamine levels and induces oxidative tissue damage which then activates inflammatory cytokines. The inflammatory cytokines suppress CYP expression and activity. This dynamic cross-talk between glucocorticoids, monoamines, and their metabolizing enzymes could be a critical factor in the pathophysiology of stress-related disorders.Lay summaryGlucocorticoids, which are produced and released under the control by brain regulatory centers, are fundamental in the stress response. This review emphasizes the importance of glucocorticoid metabolism and particularly the interaction between the brain and the liver as the major metabolic organ in the body. The activity of enzymes involved in glucocorticoid metabolism is proposed to play not only an important role in positive, healthy glucocorticoid effects, but also to contribute to the development and course of stress-related diseases.

FKBP5 methylation predicts functional network architecture of the rostral anterior cingulate cortex

DNA methylation (DNA_M) changes in the FKBP5 gene have been identified as a potential molecular mechanism explaining how environmental adversity may confer long-term health risks. However, the neurobiological correlates of epigenetic signatures in FKBP5 have only recently been explored in human brain imaging research. The present study aims to investigate associations of FKBP5 DNA_M and functional network architecture during an implicit emotion regulation task (N = 74 healthy individuals). For this, we applied a data-driven multi-voxel pattern analysis (MVPA) to identify regions, where connectivity values vary as a function of FKBP5 DNA_M, which then served as seed regions for functional network architecture analyses. Blood-derived DNA samples were obtained to analyze quantitative DNA_M at three CpGs sites in intron 7 of the FKBP5 gene using bisulfite pyrosequencing. MPVA revealed a cluster within the right rostral ACC and the paracingulate ACCs, where connectivity patterns were strongly related to FKBP5 DNA_M. Using this cluster as seed region for connectivity analyses, we further identified a functional network, including prefrontal, subcortical, insular, and thalamic regions, where connectivity patterns positively correlated with FKBP5 DNA_M. A subsequent behavioral domain analyses to determine the functional specialization of this network revealed highest effect sizes for subdomains that represent affective and cognitive processes. Together, these findings suggest that FKBP5 demethylation predicts a widespread functional disruption in a brain network centrally implicated in emotion regulation and cognition, which may in turn convey increased disease susceptibility.

Transcriptional changes in the stress pathway are related to symptoms in schizophrenia and to mood in schizoaffective disorder

Altered levels of stress-signalling transcripts have been identified in post-mortem brains of people with schizophrenia, and since stress effects may be expressed throughout the body, there should be similar changes in peripheral cells. However, the extent to which these markers are altered in peripheral white blood cells of people with schizophrenia is not known. Furthermore, how peripheral cortisol and stress-related mRNA are associated with negative symptom severity and emotional states in people with schizophrenia versus schizoaffective disorder has not been determined. Whole blood samples were collected from 86 patients with either schizophrenia or schizoaffective disorder (56 people with schizophrenia and 30 people with schizoaffective disorder), and 77 healthy controls. Total RNA was isolated, cDNA was synthesized, and stress-signalling mRNA levels (for NR3C1, FKBP5, FKBP4, PTGES3 and BAG1) were determined. Stress and symptom severity scores were measured by the Depression, Anxiety and Stress Scale, and the Positive and Negative Syndrome Scale, respectively. We found increased FKBP5 mRNA, Z(156) = 2.5, p = 0.01, decreased FKBP4 mRNA, t(155) = 3.5, p ≤ 0.001, and decreased PTGES3 mRNA, t(153) = 3.0, p ≤ 0.01, in schizophrenia and schizoaffective disorder cohorts combined compared to healthy controls. Stress-related peripheral mRNA levels were differentially correlated with negative emotional states and symptom severity in schizoaffective disorder (β's = -0.45-0.56, p's = 0.05-0.001) and schizophrenia (β's = -0.34-0.38, p's = 0.04-0.03), respectively. Therefore, molecules of the stress-signalling pathway appear to differentially contribute to clinical features of schizophrenia versus schizoaffective disorder.

Convergent neurobiological predictors of mood and anxiety symptoms and treatment response

Introduction: Mood and anxiety disorders are leading contributors to the global burden of diseases. Comorbid mood and anxiety disorders have a lifetime prevalence of ~20% globally and increases the risk for suicide, a leading cause of death. Areas covered: In this review, authors highlight recent advances in the understanding of multilevel-neurobiological mechanisms for normal/pathological human affective-functioning. The authors then address the complex interplay between environmental-adversity and molecular-genetic mediators of brain correlates of affective-symptoms. The molecular focus is strategically limited to GTF2i, BDNF, and FKBP5 genes that are, respectively, involved in transcriptional-, neurodevelopmental- and neuroendocrine-pathway mediation of affective-functions. The importance of these genes is illustrated with studies of copy-number-variants, genome-wide association (GWAS), and candidate gene-sequence variant associations with disease etiology. Authors concluded by highlighting the predictive values of integrative neurobiological processing of gene-environment interactions for affective disorder symptom management. Expert opinion: Given the transcriptional, neurodevelopmental and neuroimmune relevance of GTF2i, BDNF, and FKBP5 genes, respectively, authors reviewed the putative roles of these genes in neurobiological mediation of adaptive affective-responses. Authors discussed the importance of studying gene-dosage effects in understanding affective disorder risk biology, and how such targeted neurogenetic studies could guide precision identification of novel pharmacotherapeutic targets and aid in prediction of treatment response.

What DNA methylation modifications and/or genetic variations interact with childhood maltreatment in the development of depression: A systematic review

BACKGROUND

Child maltreatment predicts a significant risk factor for depression. The relationship between child maltreatment and depression has been shown to vary as a function of genetic factors. There have been very few systematic reviews conducted to date to synthesize what DNA methylations and/ or genetic variations interact with childhood maltreatment in the course of depression. This systematic review aimed to provide an overview of DNA methylation modifications with/without genetic variations associated with childhood maltreatment in depression.

METHODS

Computerized and manual search on six databases (EMBASE, HealthStar, PsychoInfo, Medline, PubMed and Cochrane Library) and grey literature up to June 30th 2018 were conducted. Studies were critically evaluated for their eligibility and study quality.

RESULTS

The initial search resulted in 196 articles. Five articles met the eligibility criteria being included in this review. All the selected studies were from the United States and published within the last five years. Changes in ID3, TPPP, GRIN1, and OXTR DNA methylation sites were found to be involved in the childhood maltreatment-depression relationship.

LIMITATIONS

The number of eligible articles included in this review was small. Selected articles had small sample sizes. A high degree of heterogeneity was found. It is difficult to conclude what the roles of DNA methylation modifications are in the relationship between maltreatment and depression. Population stratification has not been extensively studied so far and should be considered in the further research.

CONCLUSIONS

This review synthesizes an overview of the interaction between childhood maltreatment, DNA methylation modifications and genetic variations in depression. Findings of this review highlight an urgent need for genetic and epigenetic research in the area of childhood maltreatment and depression. Future etiological explorations should target on the above identified sites.

Allele-specific DNA methylation level of FKBP5 is associated with post-traumatic stress disorder

BACKGROUND

FK506-binding protein 5 (FKBP5) binds to glucocorticoid receptors and modulates glucocorticoid sensitivity. The FKBP5 gene has been implicated in the dysregulation of human stress responses, contributing to the risk and treatment response of stress-related disorders. The present study examined whether epigenetic changes in FKBP5 are associated with chronic post-traumatic stress disorder (PTSD) status in the context of FKBP5 genetic variation (rs1360780 polymorphism) among male veterans exposed to combat trauma.

METHODS

Korean male veterans who served on active duty during the Vietnam War were categorized into 2 groups: with PTSD (n = 123) and without PTSD (n = 116). The genotype of FKBP5 rs1360780 and DNA methylation levels of two CpG sites at the FKBP5 intron 7 region were assessed in peripheral blood. Analysis of covariance was performed to examine main and interaction effects of PTSD status and FKBP5 genotype on FKBP5 DNA methylation level, with age, trauma levels, and alcohol use as covariates.

RESULTS

A significant main effect of FKBP5 rs1360780 and PTSD and an interaction effect between genotype and PTSD status were found on mean FKBP5 DNA methylation level. The T allele of rs1360780 was associated with lower FKBP5 methylation level. In addition, the PTSD group showed significantly higher methylation than did the non-PTSD group among veterans carrying the risk T allele (n = 96), while no group difference was observed on methylation levels among veterans with the CC genotype (n = 143). Among veterans carrying the T allele, FKBP5 methylation levels were positively correlated with the severity of PTSD symptoms.

CONCLUSIONS

The present study demonstrated different FKBP5 methylation levels in PTSD depending on FKBP5 genetic variation among veterans exposed to combat trauma. The present finding suggests that the genetic and epigenetic modulation of FKBP5 is involved in the pathophysiology of PTSD. Further longitudinal research involving people exposed to trauma is required to understand causal relationships of FKBP5 in the development and recovery of PTSD.

The effects of childhood maltreatment on epigenetic regulation of stress-response associated genes: an intergenerational approach

While biological alterations associated with childhood maltreatment (CM) have been found in affected individuals, it remains unknown to what degree these alterations are biologically transmitted to the next generation. We investigated intergenerational effects of maternal CM on DNA methylation and gene expression in N = 113 mother-infant dyads shortly after parturition, additionally accounting for the role of the FKBP5 rs1360780 genotype. Using mass array spectrometry, we assessed the DNA methylation of selected stress-response-associated genes (FK506 binding protein 51 [FKBP5], glucocorticoid receptor [NR3C1], corticotropin-releasing hormone receptor 1 [CRHR1]) in isolated immune cells from maternal blood and neonatal umbilical cord blood. In mothers, CM was associated with decreased levels of DNA methylation of FKBP5 and CRHR1 and increased NR3C1 methylation, but not with changes in gene expression profiles. Rs1360780 moderated the FKBP5 epigenetic CM-associated regulation profiles in a gene × environment interaction. In newborns, we found no evidence for any intergenerational transmission of CM-related methylation profiles for any of the investigated epigenetic sites. These findings support the hypothesis of a long-lasting impact of CM on the biological epigenetic regulation of stress-response mediators and suggest for the first time that these specific epigenetic patterns might not be directly transmitted to the next generation.

Prioritization and comprehensive analysis of genes related to major depressive disorder

Background

Major depressive disorder (MDD) is a serious mental health problem in modern society, which is difficult to identify and diagnose in the early stages. Despite strong evidence supporting the heritability of MDD, progresses in large‐scale and individual genetic studies remain preliminary.

Methods

In this study, a multi‐data source‐based prioritization (MDSP) method was proposed, and an appropriate threshold was determined for the optimization of depression‐related genes (DEPgenes). Analyses on Gene Ontology biological processes, KEGG pathway and the specific pathway crosstalk network were further proposed.

Results

A total of 143 DEPgenes were identified and the MDD‐specific network was constructed for the pathogenesis investigation and therapeutic methods development of MDD. Comparing with existing research strategies, the genetic optimization and analysis results were confirmed to be reliable. Finally, the pathway enrichment and crosstalk analyses revealed two unique pathway interaction modules that were significantly enriched with MDD genes. The related core pathways of neuroactive ligand‐receptor interaction and dopaminergic synapse supported the neuropathology hypothesis of MDD. And the pathways of serotonergic synapse and morphine addiction indicated the mechanism of drug addiction caused by serotonin used in the treatment.

Conclusions

This work provided a reference for the study of MDD, although future validation by extensive experimentation is still required.

Association between FKBP5 polymorphisms and depressive disorders or suicidal behavior: A systematic review and meta-analysis study

Psychiatric disorders are complex polygenic diseases that show common genetic vulnerability. Several studies have investigated the association of polymorphisms of FK506 binding protein 51 (FKBP5) gene and depressive disorders or suicidal behavior, however, the results have been controversial and ambiguous. The aim of our study was to explore the role of the FKBP5 gene variants (rs1360780, rs3800373 and rs4713916), in depressive disorders or suicidal behavior through a systematic review and a meta-analysis. The protocol number of the study is PROSPERO CRD42018089295. The meta-analysis included 12 studies. Odds ratios with 95% confidence intervals were used to evaluate the association and the publication bias was tested by Egger's test and funnel plot; heterogeneity was assessed by the Cochran's chi-square-based Q statistic test and the inconsistency index. Our results showed that the rs3800373 and rs4713916 were associated with an increased risk of depressive disorders when using the heterozygous and dominant models. In the stratified analysis by ethnicity, a significantly increased risk of depressive disorders was also observed for rs3800373 and rs4713916 in Caucasians. When we analyzed suicidal behavior, we found a significant association with the rs1360780 of FKBP5 and suicidal behavior risk in the overall population and rs3800373 in completed suicide subgroup. Existing evidence indicates that the polymorphisms of FKBP5 gene are associated with risk of depressive disorders and suicidal behavior. Future studies with larger sample sizes will be necessary to confirm the present results.

Genes involved in stress response influence lithium efficacy in bipolar patients

OBJECTIVES

In mood disorders, chronic stimulation with stress results in aberrant regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Lithium was shown to influence HPA axis function. The underlying genetic background as well as environmental context may influence the stress response, and therefore lithium efficacy. The aim of the present study was to analyze if genetic variants located in genes involved in HPA axis regulation affect the response to long-term lithium treatment in bipolar patients.

METHODS

We included 93 patients with bipolar disorder (32 males and 61 females), aged 31-80 years. The patients had been treated with lithium carbonate for at least 5 years. The magnitude of the lithium response was assessed using the Alda scale. Genotyping was performed for 28 polymorphisms in the genes encoding the following proteins involved in HPA axis regulation: corticotropin-releasing hormone receptor 1 (CRHR1), arginine vasopressin receptor 1B (AVPR1b), FK506 binding protein (FKBP) 5, FKBP4, BCL2-associated athanogene 1 (BAG1), stress induced phosphoprotein 1 (STIP1), glucocorticoid-induced transcript 1 (GLCC1), dual specificity phosphatase 1 (DUSP1) serine and arginine rich splicing factor (SRSF) 3, SRSF9, SRSF5, and acid phosphatase 1 (ACP1). Linkage disequilibrium and haplotype analysis were then performed, followed by statistical analysis (Statistica v.12; Stasoft, Krakow, Poland).

RESULTS

We found a correlation between stressful life events at first episode and worse response to lithium (P=.019). In single marker analysis, we observed a significant association between three FKBP5 polymorphisms (rs1360780, rs7748266 and rs9296158), one ACP1 variant (rs300774) and one glucocorticoid-induced transcript 1 gene (GLCC1) variant (rs37972) and the degree of lithium response. Five out of seven FKBP5 polymorphisms showed strong linkage with one haplotype demonstrating an association with lithium efficacy (P=.008). No relationship was found between the other analyzed polymorphisms and lithium response.

CONCLUSION

The response to lithium may depend on the variants of genes regulating the HPA axis and stressful life events in bipolar patients.

Targeting the FKBP51/GR/Hsp90 Complex to Identify Functionally Relevant Treatments for Depression and PTSD

Genetic and epigenetic alterations in FK506-binding protein 5 ( FKBP5) have been associated with increased risk for psychiatric disorders, including post-traumatic stress disorder (PTSD). Some of these common variants can increase the expression of FKBP5, the gene that encodes FKBP51. Excess FKBP51 promotes hypothalamic-pituitary-adrenal (HPA) axis dysregulation through altered glucocorticoid receptor (GR) signaling. Thus, we hypothesized that GR activity could be restored by perturbing FKBP51. Here, we screened 1280 pharmacologically active compounds and identified three compounds that rescued FKBP51-mediated suppression of GR activity without directly activating GR. One of the three compounds, benztropine mesylate, disrupted the association of FKBP51 with the GR/Hsp90 complex in vitro. Moreover, we show that removal of FKBP51 from this complex by benztropine restored GR localization in ex vivo brain slices and primary neurons from mice. In conclusion, we have identified a novel disruptor of the FKBP51/GR/Hsp90 complex. Targeting this complex may be a viable approach to developing treatments for disorders related to aberrant FKBP51 expression.

DNA methylation differences at the glucocorticoid receptor gene in depression are related to functional alterations in hypothalamic-pituitary-adrenal axis activity and to early life emotional abuse

Depression is associated with alterations in hypothalamic-pituitary-adrenal (HPA) axis activity. A proposed mechanism to explain these alterations are changes in DNA methylation levels, secondary to early life adversity (ELA), at stress-related genes. Two gene regions that have been implicated in the literature, the glucocorticoid receptor gene (NR3C1) exon 1F and the FKBP5 gene intron 7 were examined in 67 individuals (33 depressed patients and 34 controls). We investigated whether cortisol concentrations, evaluated in 25 depressed patients and 20 controls, and measures of ELA were associated with the degree of methylation at these candidate gene regions. Mean NR3C1 exon 1F DNA methylation levels were significantly increased in the depressed cohort and the degree of methylation was found to be positively associated with morning cortisol concentrations. DNA methylation levels at specific CG sites within the NR3C1 exon 1F were related to childhood emotional abuse severity. DNA methylation at CG38 was related to both HPA axis and childhood emotional abuse measures in the depressed group. No FKBP5 differences were revealed. Our findings suggest that hypermethylation at the NR3C1 exon 1F may occur in depression. This locus-specific epigenetic change is associated with higher basal HPA axis activity, possibly reflecting acquired glucocorticoid receptor resistance.

Intergenerational gene × environment interaction of FKBP5 and childhood maltreatment on hair steroids

BACKGROUND

The inconsistency in results of cortisol alterations after childhood maltreatment (CM) might arise due to the fact that no study so far considered the effects of environmental factors such as maltreatment load and genetic factors such as the influence of FKBP5 genotype on stress hormone regulation. This study analyzed the interaction between the single nucleotide polymorphism rs1360780 within the FKBP5 gene and the severity of maternal CM experiences (maltreatment load) on hair steroid levels of mother-infant-dyads.

METHODS

Hair samples of N = 474 mothers and N = 331 newborns were collected < 1 week after parturition enabling a retrospective assessment of cortisol, cortisone, and dehydroepiandrosterone (DHEA) using mass spectrometry. The sum score of the Childhood Trauma Questionnaire operationalized the maternal maltreatment load. DNA from whole blood or buccal cells was used for FKBP5 genotyping.

RESULTS

The higher the maltreatment load, the higher maternal hair cortisol and cortisone levels in T allele carriers of FKBP5 rs1360780 were observed. Hair cortisol and DHEA levels of newborns with the T allele were reduced with an increasing maternal maltreatment load, while there was an increase of hair cortisol and DHEA in newborns homozygous for the C allele.

CONCLUSIONS

This study is the very first uncovering a gene (FKBP5) × environment (maltreatment load) interaction on hair steroids in mothers and their offspring, indicating an intergenerational transmission of hypothalamic-pituitary-adrenal axis alterations. These results may help to explain the inconsistency in previous findings on steroid hormone alterations after chronic and traumatic stress and should be considered in future studies.

Epigenetic Changes of FKBP5 as a Link Connecting Genetic and Environmental Risk Factors with Structural and Functional Brain Changes in Major Depression

The gene for the glucocorticoid receptor regulator FK506 binding protein 5 (FKBP5) plays a role for risk, response to treatment, and changes in brain areas in major depressive disorder (MDD). Chronic stress is associated with lower methylation of FKBP5. Our aim was to investigate whether methylation of FKBP5 reflected exposure to childhood adversity in MDD and controls and whether it was associated with structure and function of emotional processing regions. FKBP5 intron 7 GR response element region methylation and rs1360780 allelic status were assessed from whole blood in 56 MDD adults and 50 controls. Using magnetic resonance imaging, we assessed gray matter concentration of selected areas and their function during valence recognition of emotional images. Childhood adversity was investigated using the Childhood Trauma Questionnaire. In MDD patients carrying the high-risk T allele of rs1360780, lower methylation of FKBP5 was predicted by childhood adversity (F=4.95, p=0.04). In all participants, lower FKBP5 intron methylation levels were associated with reduced gray matter concentration in the inferior frontal orbital gyrus bilaterally (Wald chi-square=11.93, p_FDR<0.01) and, in MDD, with its bilaterally higher activation during valence recognition (Wald chi-square=5.58, p=0.02). Activation of this region, regardless of side, was found to be lower in MDD compared to controls (Wald chi-square=3.88, p=0.049) and to be inversely correlated with depression severity (Wald chi-square=4.65, p=0.03). Our findings support the hypothesis that, in genetically predisposed individuals carrying a high-risk variant of the gene, childhood maltreatment might induce demethylation of FKBP5. This is in turn associated with structural and functional changes in the inferior frontal orbital gyrus, a relevant area for the clinical symptoms of MDD.

The FKBP51 Glucocorticoid Receptor Co-Chaperone: Regulation, Function, and Implications in Health and Disease

Among the chaperones and co-chaperones regulating the glucocorticoid receptor (GR), FK506 binding protein (FKBP) 51 is the most intensely investigated across different disciplines. This review provides an update on the role of the different co-chaperones of Hsp70 and Hsp90 in the regulation of GR function. The development leading to the focus on FKBP51 is outlined. Further, a survey of the vast literature on the mechanism and function of FKBP51 is provided. This includes its structure and biochemical function, its regulation on different levels—transcription, post-transcription, and post-translation—and its function in signaling pathways. The evidence portraying FKBP51 as a scaffolding protein organizing protein complexes rather than a chaperone contributing to the folding of individual proteins is collated. Finally, FKBP51’s involvement in physiology and disease is outlined, and the promising efforts in developing drugs targeting FKBP51 are discussed.

Common genetic variant rs3802842 in 11q23 contributes to colorectal cancer risk in Chinese population

A genome-wide association study identified a common genetic variant rs3802842 at 11q23 to be associated with CRC risk with OR=1.1 and P = 5.80E-10 in European population. In Chinese population, several genetic association studies have investigated the association between rs3802842 variant and CRC risk. However these studies reported both positive and negative association results. It is still necessary to evaluate a specific variant in a specific population, which would be informative to reveal the disease mechanism. Until recently, there is no a systemic study to evaluate the potential association between rs3802842 and CRC risk in Chinese population by a meta-analysis method. Here, we aim to evaluate this association in Chinese population by a meta-analysis method using 12077 samples including 5816 CRC cases and 6261 controls. We identified the T allele of rs3802842 to be significantly related with an increase CRC risk (P=2.22E-05, OR=1.14, 95% CI 1.07-1.21) in Chinese population.

A latent genetic subtype of major depression identified by whole-exome genotyping data in a Mexican-American cohort

Identifying data-driven subtypes of major depressive disorder (MDD) is an important topic of psychiatric research. Currently, MDD subtypes are based on clinically defined depression symptom patterns. Although a few data-driven attempts have been made to identify more homogenous subgroups within MDD, other studies have not focused on using human genetic data for MDD subtyping. Here we used a computational strategy to identify MDD subtypes based on single-nucleotide polymorphism genotyping data from MDD cases and controls using Hamming distance and cluster analysis. We examined a cohort of Mexican-American participants from Los Angeles, including MDD patients (n=203) and healthy controls (n=196). The results in cluster trees indicate that a significant latent subtype exists in the Mexican-American MDD group. The individuals in this hidden subtype have increased common genetic substrates related to major depression and they also have more anxiety and less middle insomnia, depersonalization and derealisation, and paranoid symptoms. Advances in this line of research to validate this strategy in other patient groups of different ethnicities will have the potential to eventually be translated to clinical practice, with the tantalising possibility that in the future it may be possible to refine MDD diagnosis based on genetic data.

Common Variants in OPG Confer Risk to Bone Mineral Density Variation and Osteoporosis Fractures

Although many common variants have been identified for bone mineral density (BMD) and osteoporosis fractures, all the identified risk variants could only explain a small portion of heritability of BMD and osteoporosis fractures. OPG belongs to the tumor necrosis factor receptor superfamily, which plays a crucial role in bone remodeling and is thus a promising candidate gene of osteoporosis. Several studies have explored the association of OPG variants with BMD or osteoporosis fractures, however, the results remain inconsistent among different populations. In the study, we first assessed the relationship between OPG variants and BMD or osteoporosis fractures in our sample size (227 subjects with postmenopausal osteoporosis and 189 controls), and then performed a systematic meta-analysis. Among the nine SNPs genotyped, rs6469804 and rs2073618 showed significant associations with both BMD and osteoporotic fractures, while rs3102735 was only associated with BMD in our samples (P < 0.05). For meta-analyses, data for a total of 12 SNPs were pooled (4725 patients and 37804 controls), and five SNPs, including rs6993813, rs6469804, rs3134070, rs2073618 and rs3102734, showed association with osteoporosis fractures (P < 0.05). On light of the above analysis, we believe that OPG is one promising susceptibility gene of BMD or osteoporotic fractures.

Genetic association of rs1344706 in ZNF804A with bipolar disorder and schizophrenia susceptibility in Chinese populations

Rs1344706 in the the zinc finger protein 804A (ZNF804A) gene has been identified to be associated with schizophrenia and bipolar disorder (BD) in Europeans. However, whether rs1344706 is associated with schizophrenia in Chinese populations remains inconclusive; furthermore, the association between rs1344706 and BD in Chinese populations has been rarely explored. To explore the association between rs1344706 and schizophrenia/BD in Chinese populations, we genotyped rs1344706 among 1128 Chinese subjects (537 patients with BD and 591 controls) and found that rs1344706 showed marginal allelic association with BD (P = 0.028) with T-allele being more prevalent in cases than that in controls (OR = 1.19, 95% CI 1.03–1.37). Meta-analysis of rs1344706 by pooling all available data showed that rs1344706 was significantly associated with BD (P = 0.001). Besides, positive association of rs1344706 with schizophrenia was observed in Northern Chinese (P = 0.005). Furthermore, ZNF804A is highly expressed in human and mouse brains, especially in prenatal stage.