What can HPA axis-linked genes tell us about anxiety disorders in adolescents?

Developmental Dyslexia: Insights from EEG-Based Findings and Molecular Signatures-A Pilot Study

Developmental dyslexia (DD) is a learning disorder. Although risk genes have been identified, environmental factors, and particularly stress arising from constant difficulties, have been associated with the occurrence of DD by affecting brain plasticity and function, especially during critical neurodevelopmental stages. In this work, electroencephalogram (EEG) findings were coupled with the genetic and epigenetic molecular signatures of individuals with DD and matched controls. Specifically, we investigated the genetic and epigenetic correlates of key stress-associated genes (NR3C1, NR3C2, FKBP5, GILZ, SLC6A4) with psychological characteristics (depression, anxiety, and stress) often included in DD diagnostic criteria, as well as with brain EEG findings. We paired the observed brain rhythms with the expression levels of stress-related genes, investigated the epigenetic profile of the stress regulator glucocorticoid receptor (GR) and correlated such indices with demographic findings. This study presents a new interdisciplinary approach and findings that support the idea that stress, attributed to the demands of the school environment, may act as a contributing factor in the occurrence of the DD phenotype.

Patterns of pain complaints and insomnia symptoms are associated with abusive supervision in the Norwegian working population: a latent class analysis

OBJECTIVES

Previous findings suggest that abusive supervision, i.e., subordinates' perceptions of their supervisor's behaviours as hostile (excluding physical aggression), may increase the risk of health complaints. In addition, recent data suggest that the FKBP5 genotype rs9470080 important in the regulation of cortisol release, influences the same outcome. Adding to this complexity, different health complaints often co-occur. The present study aimed to (1) uncover patterns of pain complaints and insomnia symptoms by using latent class analysis, (2) determine whether abusive supervision or FKBP5 rs9470080 was associated with these patterns, and (3) examine the interaction between abusive supervision and FKBP5 genotype regarding pain and insomnia symptoms.

METHODS

The data was collected through a national probability survey of 5,000 employees drawn from the National Central Employee Register by Statistics Norway. Abusive supervision was measured by a 5-item version of the Tepper's 2000 scale. Pain and insomnia symptoms were measured by 5 items reflecting pain and 3 items reflecting insomnia. The FKBP5 rs9470080 genotyping was carried out using TaqMan assay.

RESULTS

A total of 1,226 participants returned the questionnaire and the saliva kit sample. Based on these the latent class analyses revealed four classes based on response patterns of pain and insomnia symptoms. In the regression analysis, abusive supervision was a significant predictor for the response patterns. However, neither the FKBP5 nor the interaction between abusive supervision and FKBP5 showed significant contributions.

CONCLUSIONS

In conclusion, awareness of the association between abusive supervision and the revealed four pain- and insomnia subgroups, and what separates them, may be important for prognosis and an optimal follow-up for those affected.

Interaction between three stress-related gene polymorphisms and food addiction increases the risk to develop obesity in a sample of Mexican people attending a nutrition clinic

Chronic stress exposure impacts negatively in individuals leading to food addiction, overweight or obesity. Stress-genes and their translation products are responsible for the responses of humans to adverse environments. Alterations in stress-genes expression or protein function may induce behaviors as compulsive eating of high-energy containing food, which decreases stress-induced negative feelings. However, chronic stress is not assessed in Mexican population. We analyzed here the association between polymorphisms of CRH, CRHR2 and glucocorticoids (GR, NR3C1) receptor genes with food addiction and obesity and overweight in Mexican patients of a Nutrition Clinic. We recruited 508 individuals of both genders, who accepted to participate in the study at their first visit to the clinic, obtaining their fat mass percentage and a blood sample for the genetic analysis. Participants answered the Yale's food addiction scale and were subjected to a Trier social test, as an acute stressful stimulus. Pre and post-test saliva samples were obtained to evaluate cortisol levels and adrenal axis' response to the acute stress. The 63% of participants classified as stressed (S); 6.5% of normal-weight individuals showed food-addiction, whereas 63% of participants with food-addiction were also stressed. The fat mass percentage was greater in stress-addiction than in stressed non-addiction participants. The best interaction model for obesity development risk comprehended the presence of polymorphisms of the three genes that in combination with food addiction increased the risk for developing obesity 2.8-4-fold. Thus, frequent stress exposure favors food-addiction, which along with genetic susceptibility seems to add up to Mexican obesity/overweight rates.

Discovery and proteomics analysis of effective compounds in Valeriana jatamansi jones for the treatment of anxiety

ETHNOPHARMACOLOGICAL RELEVANCE

Zhizhu Xiang (ZZX for short) is the root and rhizome of Valeriana jatamansi Jones, which is a Traditional Chinese Medicine (TCM) used to treat various mood disorders for more than 2000 years, especially anxiety. However, there have been few investigations to clarify the compounds in ZZX for the treatment of anxiety.

AIM OF THE STUDY

Our previous study has identified five anti-anxiety components, including hesperidin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C and chlorogenic acid, from extract of ZZX. In order to find the optimal combination and the underlying mechanism of these five components in the treatment of anxiety disorder, researches were designed based on uniform design method and proteomic technology.

MATERIALS AND METHODS

The samples with different proportion and content of the five active components were arranged by uniform design method. Then a mathematical model was formulated using partial least square method and stepwise regression analysis. Moreover, the empty bottle stress-induced anxiety rat model was established, and the anti-anxiety effect was recorded by the unconditioned reflex elevated maze test and the open field test. In addition, the isobaric tags for relative and absolute quantitation (iTRAQ) technique, along with the multidimensional liquid chromatography and high-resolution mass spectrometry were applied in proteomic study. At last, the result of proteomic analysis was further confirmed by Western blot.

RESULTS

The optimal combination of the components from the extract of ZZX was 1.153 mg/kg hesperidin, 2.197 mg/kg Isochlorogenic acid A, 0.699 mg/kg Isochlorogenic acid B and 1.249 mg/kg Chlorogenic acid. Total 6818 proteins were identified using proteomic analysis and 80 differentially expressed proteins were used for further bioinformatic analysis. These proteins were involved in the neuroactive ligand-receptor interaction, protein digestion and absorption, cholesterol metabolism, Chagas disease, and AGE/RAGE signaling pathway.

CONCLUSIONS

The composition and proportion of anti-anxiety components in extract of ZZX was disclosed, and there was an anti-anxiety effect for the combined components of flavonoids and phenolic acids. Through proteomic analysis and Western blot, it was found that the effective components of extract of ZZX can exert synergistic anti-anxiety effects via the regulation of multi-signaling pathways. These findings could provide a preliminary research basis for the development of new low-toxic, efficient, stable and controllable anti-anxiety drugs.

The influence of age, gender and the FKBP5 genotype on subjective health complaints in the Norwegian working population

OBJECTIVE

In the present study we examined the potential association between age, gender, the genetic variant FKBP5 rs9470080 and subjective health complaints.

METHODS

The data were collected through a three-wave nationally representative survey of 1060 Norwegian employees drawn from the Norwegian Central Employee Register by Statistics Norway. The follow-up period was six months. Subjective health complaints were scored by eight items reflecting; headache, neck pain, mid- and low back pain, stomach cramps or intestinal discomfort, problems with sleep onset or maintenance and early morning awakening. Genotyping with regard to FKBP5 rs9470080, previously linked to cortisol sensitivity, was carried out using Taqman assay.

RESULTS

The baseline data showed that in women, levels of subjective health complaints were highest among those above 50 years of age. Moreover, in women the rs9470080 CC variant at baseline was associated with higher levels of subjective health complaints. However, the effect size was not large, and no relationships were demonstrated between age or genotype and subjective health complaints in men. Also, the study variables were not related to any changes in the levels of subjective health complaints during the follow-up period.

CONCLUSION

We conclude that our biology such as age and sex, but also single genetic variants found in non-sex chromosomes, may be important in understanding the mechanisms underlying subjective health complaints in the general working population.

Prenatal maternal vaginal inflammation increases anxiety and alters HPA axis signalling in adult male mice

BACKGROUND

Maternal infection during pregnancy is known to adversely affect foetal development, but previous studies have rarely investigated the impact of gynaecological diseases during pregnancy on offspring during adulthood. Vaginitis is one of the most prevalent gynaecological diseases during pregnancy.

METHODS

The effect of maternal vaginal inflammation on offspring was simulated by inducing maternal vaginal infection. We performed a transvaginal injection of lipopolysaccharide (LPS) in pregnant mice to induce vaginitis and investigated their offspring by means of behavioural tests and molecular and cellular measurements.

RESULTS

Behavioural tests revealed that the offspring of mothers transvaginally injected with LPS exhibited sex-dependent differences. Male offspring showed increased anxiety-related behaviours, including reduced time exploring the open arm in the elevated plus maze test and light chamber in the light-dark box test. Serum levels of corticosterone were increased in LPS male offspring, indicating activation of the hypothalamic-pituitary-adrenal (HPA) axis. Corticotropin-releasing hormone (CRH) protein expression and c-Fos positive cells were increased in the hypothalamic paraventricular nucleus (PVN) in LPS male offspring, which presented with an increased number of microglia.

CONCLUSION

This study suggests that prenatal vaginal infection increases anxiety-like behaviour in male offspring, possibly via activation of the HPA axis.

Altered Global mRNA Expressions of Pain and Aggression Related Genes in the Blood of Children with Autism Spectrum Disorders

Autism spectrum disorder (ASD) is characterized by repetitive stereotypic behaviors, restricted interests, social withdrawal, and communication deficits. Aggression and insensitivity to pain are largely unexplained in these cases. We analyzed nine mRNA expressions of the candidate genes related to aggression and insensitivity to pain in the peripheral blood of patients with ASD. Whole blood samples were obtained from 40 autistic patients (33 boys, 7 girls) and 50 age- and sex-matched controls (37 boys and 13 girls) to isolate RNA. Gene expression was assessed by quantitative Real-Time PCR (qRT-PCR) in the Erciyes University Genome and Stem Cell Center (GENKOK). All of the gene expressions except CRHR1 and SLC6A4 were found to be statistically different between the ASD patients and controls. Gene expression also differed according to gender. Alterations in the mRNA expression patterns of the HTR1E, OPRL1, OPRM1, TACR1, PRKG1, SCN9A and DRD4 genes provide further evidence for a relevant effect of the respective candidate genes on the pathophysiology of ASD. Future studies may determine the sensitivity of these candidate markers in larger samples including further neuropsychiatric diagnosis.

Identification of Bioactive Chemical Markers in Zhi zhu xiang Improving Anxiety in Rat by Fingerprint-Efficacy Study

Zhi zhu xiang (ZZX for short) is the root and rhizome of Valeriana jatamansi Jones, which is a Traditional Chinese Medicine (TCM) used to treat various mood disorders for more than 2000 years, especially anxiety. The aim of the present work was to identify the bioactive chemical markers in Zhi zhu xiang improving anxiety in rats by a fingerprint-efficacy study. More specifically, the chemical fingerprint of ZZX samples collected from 10 different regions was determined by High Performance Liquid Chromatography (HPLC) and the similarity analyses were calculated based on 10 common characteristic peaks. The anti-anxiety effect of ZZX on empty bottle stimulated rats was examined through the Open Field Test (OFT) and the Elevated Plus Maze Test (EPM). Then we measured the concentration of CRF, ACTH, and CORT in rat’s plasma by the enzyme-linked immune sorbent assay (ELISA) kit, while the concentration of monoamine and metabolites (NE, DA, DOPAC, HVA, 5-HT, 5-HIAA) in the rat’s cerebral cortex and hippocampus was analysed by HPLC coupled with an Electrochemical Detector. At last, the fingerprint-efficacy study between chemical fingerprint and anti-anxiety effect of ZZX was accomplished by partial least squares regression (PLSR). As a result, we screened out four compounds (hesperidin, isochlorogenic acid A, isochlorogenic acid B and isochlorogenic acid C) as the bioactive chemical markers for the anti-anxiety effect of ZZX. The fingerprint-efficacy study we established might provide a feasible way and some elicitation for the identification of the bioactive chemical markers for TCM.

Hsp90 and FKBP51: complex regulators of psychiatric diseases

Mood disorders affect nearly a quarter of the world's population. Therefore, understanding the molecular mechanisms underlying these conditions is of great importance. FK-506 binding protein 5 (FKBP5) encodes the FKBP51 protein, a heat shock protein 90 kDa (Hsp90) co-chaperone, and is a risk factor for several affective disorders. FKBP51, in coordination with Hsp90, regulates glucocorticoid receptor (GR) activity via a short negative feedback loop. This signalling pathway rapidly restores homeostasis in the hypothalamic-pituitary-adrenal (HPA) axis following stress. Expression of FKBP5 increases with age through reduced DNA methylation. High levels of FKBP51 are linked to GR resistance and reduced stress coping behaviour. Moreover, common allelic variants in the FKBP5 gene are associated with increased risk of developing affective disorders like anxiety, depression and post-traumatic stress disorder (PTSD). This review highlights the current understanding of the Hsp90 co-chaperone, FKBP5, in disease from both human and animal studies. In addition, FKBP5 genetic implications in the clinic involving life stress exposure, gender differences and treatment outcomes are discussed.This article is part of the theme issue 'Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective'.

Hypothalamic-pituitary-adrenal axis variants and childhood trauma influence anxiety sensitivity in South African adolescents

Anxiety sensitivity (AS) is characterised by the fear of anxiety-related symptoms and is a risk factor for the development of anxiety-related disorders. We examined whether genetic variation in three stress response genes, CRHR1, NR3C1, and FKBP5, interact with childhood trauma (CT) to predict AS in South African adolescents. Xhosa (n = 634) and Coloured (n = 317) students completed self-report measures of AS and CT, and a total of eighteen polymorphisms within CRHR1, NR3C1, and FKBP5 were genotyped. Differences in AS based on genetic variation and CT were analysed within population and gender groups using multiple linear regression. Associations were found between AS and FKBP5 rs9296158 (p = 0.025) and rs737054 (p = 0.045) in Coloured males. Analysis of gene x CT interactions indicated that NR3C1 rs190488 CC-genotype, NR3C1 rs10482605 G-allele addition, and FKBP5 rs3800373 C-allele addition protect against AS with increasing CT in Xhosa females (p = 0.009), Xhosa males (p = 0.036) and Coloured males (p = 0.049), respectively. We identified two different protective single nucleotide polymorphism (SNP) combinations in a four-SNP CRHR1 haplotype in Coloured males. An analysis of the interaction between CT and a six-SNP FKBP5 haplotype in Coloured males revealed both protective and risk allelic combinations. Our results provide evidence for the influence of both genetic variation in CRHR1, NR3C1 and FKBP5, as well as CT x SNP interactions, on AS in South African adolescents. This study reinforces the importance of examining the influence of gene-environment (G X E) interactions within gender and population groups.

The emerging role of the FKBP5 gene polymorphisms in vulnerability-stress model of schizophrenia: further evidence from a Serbian population

Increased reactivity to stress is observed in patients with schizophrenia spectrum disorders and their healthy siblings in comparison with the general population. Additionally, higher levels of neuroticism, as a proposed psychological measure of stress sensitivity, increase the risk of schizophrenia. HPA axis dysregulation is one of the possible mechanisms related to the vulnerability-stress model of schizophrenia, and recent studies revealed a possible role of the functional genetic variants of FK506-binding protein 51 (FKBP5) gene which modulate activity of HPA axis. The purpose of the present study was to investigate impact of FKBP5 on schizophrenia in Serbian patients and to explore relationship between genetic variants and neuroticism by using the case-sibling-control design. In 158 subjects, we measured psychotic experiences, childhood trauma and neuroticism. Nine single-nucleotide polymorphisms (rs9295158, rs3800373, rs9740080, rs737054, rs6926133, rs9380529, rs9394314, rs2766533 and rs12200498) were genotyped. The genetic influence was modeled using logistic regression, and the relationship between genetic variants and neuroticism was assessed by linear mixed model. Our results revealed genetic main effect of FKBP5 risk alleles (A allele of rs9296158 and T allele of rs3800373) and AGTC "risk" haplotype combination (rs9296158, rs3800373, rs9470080 and rs737054, respectively) on schizophrenia, particularly when childhood trauma was set as a confounding factor. We confirmed strong relationship between neuroticism and psychotic experiences in patients and siblings and further showed relationship between higher levels of neuroticism and FKBP5 risk variants suggesting potential link between biological and psychosocial risk factors. Our data support previous findings that trauma exposure shapes FKBP5 impact on schizophrenia.

Effects of corticotropin-releasing hormone receptor 1 SNPs on major depressive disorder are influenced by sex and smoking status

BACKGROUND

The corticotropin-releasing hormone receptor 1 (CRHR1) gene has been repeatedly implicated in Major Depressive Disorder (MDD) in humans and animal models; however, the findings are not absolutely convergent. Since recent evidence from genome-wide association studies suggests that narrowing the phenotypic heterogeneity may be crucial in genetic studies of MDD, the aim of this study was to evaluate the effects of CRHR1 polymorphisms on MDD while addressing the influence of sex and smoking status.

METHODS

The association of the CRHR1 SNPs rs12944712, rs110402, and rs878886 with MDD was evaluated in 629 Brazilian adults of European descent recruited from the general population [180 (28.6%) with lifetime MDD]. The sample was subdivided according to sex and smoking status RESULTS: Among nonsmokers, there were nominal associations between MDD and all tested SNPs (rs12944712, P=0.042; rs110402, P=0.031, and rs878886, P=0.040), regardless of sex. In addition, there were significant effects of rs110402 in women (P_corr=0.034) and rs878886 in men (P_corr=0.013). Among lifetime smokers, there were no significant associations between CRHR1 SNPs and MDD LIMITATIONS: The lack of a depression rating scale; scarcity of information on the functionality of the CRHR1 SNPs; and relatively small sample sizes in some subgroups.

CONCLUSIONS

Our results strengthen the evidence for the role of CRHR1 SNPs in MDD susceptibility and suggest that their effects may be modulated by sex and smoking status. These findings suggest the perspective that reducing phenotypic heterogeneity is warranted in genetic studies of MDD.