Glucocorticoid Receptor Polymorphisms in Major Depression

Neuropsychiatric Adverse Effects of Synthetic Glucocorticoids: A Systematic Review and Meta-Analysis

CONTEXT

Synthetic glucocorticoids are widely used to treat patients with a broad range of diseases. While efficacious, glucocorticoids can be accompanied by neuropsychiatric adverse effects.

OBJECTIVE

This systematic review and meta-analysis assesses and quantifies the proportion of different neuropsychiatric adverse effects in patients using synthetic glucocorticoids.

METHODS

Six electronic databases were searched to identify potentially relevant studies. Randomized controlled trials, cohort studies, and cross-sectional studies assessing psychiatric side effects of glucocorticoids measured with validated questionnaires were eligible. Risk of bias was assessed with RoB 2, ROBINS-I, and AXIS appraisal tool. For proportions of neuropsychiatric outcomes, we pooled proportions, and when possible, differences in questionnaire scores between glucocorticoid users and nonusers were expressed as standardized mean differences (SMD). Data were pooled in a random-effects logistic regression model.

RESULTS

We included 49 studies with heterogeneity in study populations, type, dose, and duration of glucocorticoids. For glucocorticoid users, meta-analysis showed a proportion of 22% for depression (95% CI, 14%-33%), 11% for mania (2%-46%), 8% for anxiety (2%-25%), 16% for delirium (6%-36%), and 52% for behavioral changes (42%-61%). Questionnaire scores for depression (SMD of 0.80 [95% CI 0.35-1.26]), and mania (0.78 [0.14-1.42]) were higher than in controls, indicating more depressive and manic symptoms following glucocorticoid use.

CONCLUSION

The heterogeneity of glucocorticoid use is reflected in the available studies. Despite this heterogeneity, the proportion of neuropsychiatric adverse effects in glucocorticoid users is high. The most substantial associations with glucocorticoid use were found for depression and mania. Upon starting glucocorticoid treatment, awareness of possible psychiatric side effects is essential. More structured studies on incidence and potential pathways of neuropsychiatric side effects of prescribed glucocorticoids are clearly needed.

Prognostic Value of SGK1 and Bcl-2 in Invasive Breast Cancer

It is crucial to understand molecular alterations in breast cancer and how they relate to clinicopathologic factors. We have previously shown that the glucocorticoid receptor (GCR) protein expression was reduced in invasive breast carcinoma compared to normal breast tissue. Glucocorticoids, signaling through the GCR, regulate several cellular processes via downstream targets such as serum/glucocorticoid-regulated kinase 1 (SGK1) and B-cell lymphoma 2 (Bcl-2). We measured the expression of SGK1 and Bcl-2, in respective breast cancer tissue arrays, from a multiracial cohort of breast cancer patients. Higher cytoplasmic SGK1 staining was stronger in breast cancer tissue compared to normal tissue, especially in hormone receptor-negative cases. Conversely, the expression of cytoplasmic Bcl-2 was reduced in breast cancer compared to normal tissue, especially in hormone receptor-negative cases. Bcl-2 staining was associated with the self-reported racial/ethnic category, an earlier clinical stage, a lower histological grade, and a higher survival rate. Bcl-2 expression was associated with longer survival in models adjusted for age and race (HR = 0.32, 95% CI: 0.15, 0.65), and Bcl-2 expression remained strongly positively associated with protection from breast cancer death, with additional adjustments for ER/PR status (HR = 0.41, 95% CI: 0.2, 0.85). SGK1 and Bcl-2 may play biological roles in breast cancer development and/or progression.

Unraveling Dexamethasone-Induced Neurobehavioral and Sleep Problems in Children With ALL: Which Determinants Are Important?

PURPOSE

Dexamethasone, the preferred corticosteroid in most treatment protocols for pediatric acute lymphoblastic leukemia (ALL), can induce undesirable side effects. Neurobehavioral and sleep problems are frequently reported, but the interpatient variability is high. We therefore aimed to identify determinants for parent-reported dexamethasone-induced neurobehavioral and sleep problems in pediatric ALL.

METHODS

Our prospective study included patients with medium-risk ALL and their parents during maintenance treatment. Patients were assessed before and after one 5-day dexamethasone course. Primary end points were parent-reported dexamethasone-induced neurobehavioral and sleep problems, measured with the Strengths and Difficulties Questionnaire and Sleep Disturbance Scale for Children, respectively. Analyzed determinants included patient and parent demographics, disease and treatment characteristics, parenting stress (Parenting Stress Index and Distress Thermometer for Parents), dexamethasone pharmacokinetics, and genetic variation (candidate single-nucleotide polymorphisms rs41423247 and rs4918). Statistically significant determinants identified in univariable logistic regression analyses were incorporated in a multivariable model.

RESULTS

We included 105 patients: median age was 5.4 years (range, 3.0-18.8) and 61% were boys. Clinically relevant dexamethasone-induced neurobehavioral and sleep problems were reported by parents in 70 (67%) and 61 (59%) patients, respectively. In our multivariable regression models, we identified parenting stress as a significant determinant for parent-reported neurobehavioral (odds ratio [OR], 1.16; 95% CI, 1.07 to 1.26) and sleep problems (OR, 1.06; 95% CI, 1.02 to 1.10). Furthermore, parents who experienced more stress before start of a dexamethasone course reported more sleep problems in their child (OR, 1.16; 95% CI, 1.02 to 1.32).

CONCLUSION

We identified parenting stress, and not dexamethasone pharmacokinetics, genetic variation, patient/parent demographics, or disease/treatment characteristics, as a significant determinant for parent-reported dexamethasone-induced neurobehavioral and sleep problems. Parenting stress may be a modifiable target to reduce these problems.

From Ligands to Behavioral Outcomes: Understanding the Role of Mineralocorticoid Receptors in Brain Function

Stress is a normal response to situational pressures or demands. Exposure to stress activates the hypothalamic-pituitary-adrenal (HPA) axis and leads to the release of corticosteroids, which act in the brain via two distinct receptors: mineralocorticoid receptors (MR) and glucocorticoid receptors (GR). Persistent HPA axis overactivation or dysregulation can disrupt an individual's homeostasis, thereby contributing to an increased risk for mental illness. On the other hand, successful coping with stressful events involves adaptive and cognitive processes in the brain that render individuals more resilient to similar stressors in the future. Here we review the role of the MR in these processes, starting with an overview of the physiological structure, ligand binding, and expression of MR, and further summarizing its role in the brain, its relevance to psychiatric disorders, and related rodent studies. Given the central role of MR in cognitive and emotional functioning, and its importance as a target for promoting resilience, future research should investigate how MR modulation can be used to alleviate disturbances in emotion and behavior, as well as cognitive impairment, in patients with stress-related psychiatric disorders.

Early life stress, depression and epigenetics

Different factors are essential in increasing the vulnerability to psychiatric disorders, such as genetics. Among these factors, early life stress (ELS), including sexual, physical, emotional abuse, and emotional and physical neglect, enhances the odds of having menial conditions throughout life. Exhaustive research has shown that ELS leads to physiological changes, such as alteration in the HPA axis. During the most critical development period (childhood and adolescence), these changes increase the risk of having child-onset psychiatric disorders. Furthermore, research has suggested a relationship between early life stress and depression, particularly more prolonged episodes of depression with treatment-resistant outcomes. Molecular studies indicate that, in general, the hereditary character of psychiatric disorders is polygenic, multifactorial and highly complex, with innumerable low-effect genetic variants interacting with each other. However, whether there are independent effects among subtypes of ELS remains unclear. This article provides an overview of the interplay of epigenetics, the HPA axis, early life stress and the development of depression. Advances in our knowledge of epigenetics in the context of early life stress and depression provide a new understanding of the genetic influence on psychopathology. Furthermore, they could lead to identifying new targets for clinical intervention.

The Glucocorticoid Receptor Polymorphism Landscape in Patients With Diamond Blackfan Anemia Reveals an Association Between Two Clinically Relevant Single Nucleotide Polymorphisms and Time to Diagnosis

NR3C1, the gene encoding the glucocorticoid receptor, is polymorphic presenting numerous single nucleotide polymorphisms (SNPs) some of which are emerging as leading cause in the variability of manifestation and/or response to glucocorticoids in human diseases. Since 60–80% of patients with Diamond Blackfan anemia (DBA), an inherited pure red cell aplasia induced by mutations in ribosomal protein genes became transfusion independent upon treatment with glucocorticoids, we investigated whether clinically relevant NR3C1 SNPs are associated with disease manifestation in DBA. The eight SNPs rs10482605, rs10482616, rs7701443, rs6189/rs6190, rs860457, rs6198, rs6196, and rs33388/rs33389 were investigated in a cohort of 91 European DBA patients. Results were compared with those observed in healthy volunteers (n=37) or present in public genome databases of Italian and European populations. Although, cases vs. control analyses suggest that the frequency of some of the minor alleles is significantly altered in DBA patients with respect to healthy controls or to the Italian or other European registries, lack of consistency among the associations across different sets suggests that overall the frequency of these SNPs in DBA is not different from that of the general population. Demographic data (47 females and 31 males) and driver mutations (44 S and 29 L genes and eight no-known mutation) are known for 81 patients while glucocorticoid response is known, respectively, for 81 (36 responsive and 45 non-responsive) and age of disease onsets for 79 (55 before and 24 after 4months of age) patients. Neither gender nor leading mutations were associated with the minor alleles or with disease manifestation. In addition, none of the SNPs met the threshold in the response vs. non-responsive groups. However, two SNPs (rs6196 and rs860457) were enriched in patients manifesting the disease before 4months of age. Although the exact biomechanistical consequences of these SNPs are unknown, the fact that their configuration is consistent with that of regulatory regions suggests that they regulate changes in glucocorticoid response during ontogeny. This hypothesis was supported by phosphoproteomic profiling of erythroid cells expanded ex vivo indicating that glucocorticoids activate a ribosomal signature in cells from cord blood but not in those from adult blood, possibly providing a compensatory mechanism to the driving mutations observed in DBA before birth.

Study protocol: DexaDays-2, hydrocortisone for treatment of dexamethasone-induced neurobehavioral side effects in pediatric leukemia patients: a double-blind placebo controlled randomized intervention study with cross-over design

BACKGROUND

Dexamethasone, a highly effective drug in treating pediatric acute lymphoblastic leukemia (ALL), can induce serious neurobehavioral side effects. These side effects are experienced by patients and parents as detrimental with respect to health related quality of life (HRQoL). Based on previous studies, it has been suggested that neurobehavioral side effects are associated to cortisol depletion of the mineralocorticoid receptor in the brain. Our previously reported randomized controlled trial, the Dexadagen study (NTR3280), suggests that physiological hydrocortisone addition during dexamethasone treatment may overcome clinically relevant neurobehavioral problems in patients who experience these problems during dexamethasone treatment. With our current study, we aim to replicate these results in a targeted larger sample before further implementing this intervention into standard of care.

METHODS

In a national center setting, pediatric ALL patients between 3 and 18 years are enrolled in an Identification study, which identifies patients with clinically relevant dexamethasone-induced neurobehavioral side effects using the Strengths and Difficulties Questionnaire (SDQ). Contributing factors, such as genetic susceptibility, dexamethasone pharmacokinetics as well as psychosocial and family factors are studied to determine their influence in the inter-patient variability for developing dexamethasone-induced neurobehavioral side effects. Patients with clinically relevant problems (i.e. a rise of ≥ 5 points on the SDQ Total Difficulties Score after 5 days of dexamethasone) are subsequently included in a randomized double-blind placebo-controlled trial with a cross-over design. They receive two courses placebo followed by two courses hydrocortisone during dexamethasone treatment, or vice versa, each time at least 16 days without study medication in between. The primary endpoint is change in SDQ score. The secondary endpoints are sleep (measured with actigraphy and the Sleep Disturbance Scale for Children) and HRQoL (Pediatric Quality of Life Questionnaire).

DISCUSSION

The results of our current study may contribute to the management of future ALL patients who experience dexamethasone-induced neuropsychological problems as it may improve HRQoL for patients who suffer most from dexamethasone-induced neurobehavioral side effects. Furthermore, by investigating multiple risk factors that could be related to inter-patient variability in developing these side effects, we might be able to identify and treat patients who are at risk earlier during treatment.

TRIAL REGISTRATION

Medical Ethical Committee approval number: NL62388.078.17. Affiliation: Erasmus Medical Centre. Netherlands Trial Register: NL6507 ( NTR6695 ). Registered 5 September 2017.

Genetic Variation and Immunohistochemical Localization of the Glucocorticoid Receptor in Breast Cancer Cases from the Breast Cancer Care in Chicago Cohort

BACKGROUND

Glucocorticoid, one of the primary mediators of stress, acts via its receptor, the glucocorticoid receptor (GCR/NR3C1), to regulate a myriad of physiological processes. We measured the genetic variation and protein expression of GCR, and the genes that regulate GCR function or response and examined whether these alterations were associated with breast cancer clinicopathological characteristics.

METHOD

We used samples from a multiracial cohort of breast cancer patients to assess the association between breast cancer characteristics and the genetic variants of single nucleotide polymorphisms (SNPs) in GCR/NR3C1, FKBP5, Sgk1, IL-6, ADIPOQ, LEPR, SOD2, CAT, and BCL2.

RESULTS

Several SNPs were associated with breast cancer characteristics, but statistical significance was lost after adjustment for multiple comparisons. GCR was detected in all normal breast tissues and was predominantly located in the nuclei of the myoepithelial cell layer, whereas the luminal layer was negative for GCR. GCR expression was significantly decreased in all breast cancer tissue types, compared to nontumor tissue, but was not associated with breast cancer characteristics. We found that high nuclear GCR expression was associated with basal cell marker cytokeratin 5/6 positivity.

CONCLUSION

GCR expression is reduced in breast cancer tissue and correlates with the basal cell marker CK5/6.

Risk factors for steroid-induced adverse psychological reactions and sleep problems in pediatric acute lymphoblastic leukemia: A systematic review

OBJECTIVE

Steroids play an essential role in treating pediatric acute lymphoblastic leukemia (ALL). The downside is that these drugs can cause severe side effects, such as adverse psychological reactions (APRs) and sleep problems, which can compromise health-related quality of life. This study aimed to systematically review literature to identify risk factors for steroid-induced APRs and sleep problems in children with ALL.

METHODS

A systematic search was performed in six databases. Titles/abstracts were independently screened by two researchers. Data from each included study was extracted based on predefined items. Risk of bias and level of evidence were assessed, using the Quality in Prognosis Studies tool and the Grading of Recommendations Assessment, Development and Evaluation tool, respectively.

RESULTS

Twenty-four articles were included. APR measurement ranged from validated questionnaires to retrospective record retrieval, sleep measurement included questionnaires or actigraphy. Overall, quality of evidence was very low. Current evidence suggests that type/dose of steroid is not related to APRs, but might be to sleep problems. Younger patients seem at risk for behavior problems and older patients for sleep problems. No studies describing parental stress or medical history were identified. Genetic susceptibility associations remain to be replicated.

CONCLUSIONS

Based on the current evidence, conclusions about risk factors for steroid-induced adverse psychological reactions or sleep problems in children with ALL should be drawn cautiously, since quality of evidence is low and methods of measurement are largely heterogeneous. A standardized registration of steroid-induced APRs/sleep problems and risk factors is warranted for further studies in children with ALL.

Molecular characterization of the stress network in individuals at risk for schizophrenia

The biological mechanisms underlying inter-individual differences in human stress reactivity remain poorly understood. We aimed to identify the molecular underpinning of aberrant neural stress sensitivity in individuals at risk for schizophrenia. Linking mRNA expression data from the Allen Human Brain Atlas to task-based fMRI revealed 201 differentially expressed genes in cortex-specific brain regions differentially activated by stress in individuals with low (healthy siblings of schizophrenia patients) or high (healthy controls) stress sensitivity. These genes are associated with stress-related psychiatric disorders (e.g. schizophrenia and anxiety) and include markers for specific neuronal populations (e.g. ADCYAP1, GABRB1, SSTR1, and TNFRSF12A), neurotransmitter receptors (e.g. GRIN3A, SSTR1, GABRB1, and HTR1E), and signaling factors that interact with the corticosteroid receptor and hypothalamic-pituitary-adrenal axis (e.g. ADCYAP1, IGSF11, and PKIA). Overall, the identified genes potentially underlie altered stress reactivity in individuals at risk for schizophrenia and other psychiatric disorders and play a role in mounting an adaptive stress response in at-risk individuals, making them potentially druggable targets for stress-related diseases.

Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Approximately 45 million people worldwide are diagnosed with bipolar disorder (BD). While there are many known risk factors and models of the pathologic processes influencing BD, the exact neurologic underpinnings of BD are unknown. We attempt to integrate the existing literature and create a unifying hypothesis regarding the pathophysiology of BD with the hope that a concrete model may potentially facilitate more specific diagnosis, prevention, and treatment of BD in the future. We hypothesize that dysfunctional signaling from the parvocellular neurons of the paraventricular hypothalamic nucleus (PVN) results in the clinical presentation of BD. Functional damage to this nucleus and its signaling pathways may be mediated by myriad factors (e.g. immune dysregulation and auto-immune processes, polygenetic variation, dysfunctional interhemispheric connections, and impaired or overactivated hypothalamic axes) which could help explain the wide variety of clinical presentations along the BD spectrum. The neurons of the PVN regulate ultradian rhythms, which are observed in cyclic variations in healthy individuals, and mediate changes in functional hemispheric lateralization. Theoretically, dysfunctional PVN signaling results in prolonged functional hemispheric dominance. In this model, prolonged right hemispheric dominance leads to depressive symptoms, whereas left hemispheric dominance correlated to the clinical picture of mania. Subsequently, physiologic processes that increase signaling through the PVN (hypothalamic-pituitaryadrenal axis, hypothalamic- pituitary-gonadal axis, and hypothalamic-pituitary-thyroid axis activity, suprachiasmatic nucleus pathways) as well as, neuro-endocrine induced excito-toxicity, auto-immune and inflammatory flairs may induce mood episodes in susceptible individuals. Potentially, ultradian rhythms slowing with age, in combination with changes in hypothalamic axes and maturation of neural circuitry, accounts for BD clinically presenting more frequently in young adulthood than later in life.

The biological underpinnings of perinatal depressive symptoms: A multi-systems approach

BACKGROUND

Well-established evidence exists of an association between depressive symptoms and alterations in the stress and inflammatory response systems; however, the picture is far less coherent during the perinatal period. This study combines the assessment of multiple stress and inflammatory biomarkers in late pregnancy and after delivery in order to investigate cross-sectional and prospective associations with perinatal depressive symptoms.

METHODS

One-hundred-ten healthy women were assessed in late pregnancy (mean gestational age=34.76; SD=1.12) and 89 were re-evaluated after delivery (mean hours after delivery=52.36; SD=19.70) for depressive and anxiety symptoms through the Edinburgh Postnatal Depression Scale and the State-Trait Anxiety Inventory. Serum Interleukin-6 (IL-6), C-Reactive Protein (CRP) and diurnal salivary cortisol levels were measured on both occasions, while diurnal salivary alpha amylase (sAA) levels were assessed in late pregnancy.

RESULTS

Using Hierarchical Linear Models, higher depressive symptoms were found to be associated with higher IL-6 levels, lower morning cortisol levels and a flatter cortisol diurnal slope during pregnancy, while adjusting for potential confounders. No significant associations were found after delivery or with change in biomarker levels from pre- to post-partum. Furthermore, preliminary evidence of a positive association between inflammation and stress markers in women with higher antenatal depressive symptoms was found.

LIMITATIONS

The sample was relatively small and highly selected, thus limiting generalizability of the findings.

CONCLUSIONS

Results emphasize the need for an integrated multi-systems approach to the understanding of the biological underpinnings of perinatal depression and suggest that the stress-immune interactions represent a promising avenue for future endeavor.

Hypothalamic-pituitary-adrenal axis-related genes and cognition in major mood disorders and schizophrenia: a systematic review

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation and cognitive deficits are two well-characterized endophenotypes present in different serious mental illnesses (SMIs), including major depressive disorder, bipolar disorder and schizophrenia. Our aim was to study the influence of genetic and epigenetic variations in HPA axis-related genes on cognitive performance in clinical samples, including patients with major mood disorders and schizophrenia. A systematic search was performed using PubMed (Medline), PsycINFO and Scopus databases. The systematic review identified 12 studies dealing with HPA-related genes and cognition in samples including patients with SMIs, focusing on single nucleotide polymorphism (SNP) variants, while no studies analysing epigenetic variations were found. The results suggest different and specific effects on the cognitive performance of SNP variants in the HPA axis-related genes studied, as well as interactions with traumatic experiences. There was high heterogeneity in the studied samples, genes analysed, and cognitive tasks evaluated. The relationship between HPA-related genes and cognition in SMIs is still largely unknown, and further studies including larger samples and epigenetic variations are needed.

A new model for the HPA axis explains dysregulation of stress hormones on the timescale of weeks

Stress activates a complex network of hormones known as the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis is dysregulated in chronic stress and psychiatric disorders, but the origin of this dysregulation is unclear and cannot be explained by current HPA models. To address this, we developed a mathematical model for the HPA axis that incorporates changes in the total functional mass of the HPA hormone-secreting glands. The mass changes are caused by HPA hormones which act as growth factors for the glands in the axis. We find that the HPA axis shows the property of dynamical compensation, where gland masses adjust over weeks to buffer variation in physiological parameters. These mass changes explain the experimental findings on dysregulation of cortisol and ACTH dynamics in alcoholism, anorexia, and postpartum. Dysregulation occurs for a wide range of parameters and is exacerbated by impaired glucocorticoid receptor (GR) feedback, providing an explanation for the implication of GR in mood disorders. These findings suggest that gland-mass dynamics may play an important role in the pathophysiology of stress-related disorders.

The hypothalamic-pituitary-adrenal axis as a substrate for stress resilience: Interactions with the circadian clock

Stress, primarily processed via the hypothalamic-pituitary-adrenal (HPA) axis, engages biological pathways throughout the brain and body which promote adaptation and survival to changing environmental demands. Adaptation to environmental challenges is compromised when these pathways are no longer functioning optimally. The physiological and behavioral mechanisms through which HPA axis function influences stress adaptation and resilience are not fully elucidated. Our understanding of stress biology and disease must take into account the complex interactions between the endocrine system, neural circuits, and behavioral coping strategies. In addition, further consideration must be taken concerning influences of other aspects of physiology, including the circadian clock which is critical for regulation of daily changes in HPA activity. While adding a layer of complexity, it also offers targets for intervention. Understanding the role of HPA function in mediating these diverse biological responses will lead to important insights about how to bolster successful stress adaptation and promote stress resilience.

Cognitive dysfunction in mice lacking proper glucocorticoid receptor dimerization

Stress is a major risk factor for depression and anxiety. One of the effects of stress is the (over-) activation of the hypothalamic-pituitary-adrenal (HPA) axis and the release of stress hormones such as glucocorticoids (GCs). Chronically increased stress hormone levels have been shown to have detrimental effects on neuronal networks by inhibiting neurotrophic processes particularly in the hippocampus proper. Centrally, GCs modulate metabolic as well as behavioural processes by activating two classes of corticoid receptors, high-affinity mineralocorticoid receptors (MR) and low-affinity glucocorticoid receptors (GR). Upon activation, GR can modulate gene transcription either as a monomeric protein, or as a dimer interacting directly with DNA. GR can also modulate cellular processes via non-genomic mechanisms, for example via a GPCR-protein interaction. We evaluated the behavioral phenotype in mice with a targeted mutation in the GR in a FVB/NJ background. In GRdim/dim mice, GR proteins form poor homodimers, while the GR monomer remains intact. We evaluated the effect of poor GR dimerization on hippocampus-dependent cognition as well as on exploration and emotional behavior under baseline and chronically increased stress hormone levels. We found that GRdim/dim mice did not behave differently from GRwt/wt littermates under baseline conditions. However, after chronic elevation of stress hormone levels, GRdim/dim mice displayed a significant impairment in hippocampus-dependent memory compared to GRwt/wt mice, which correlated with differential expression of hippocampal Bdnf/TrkB and Fkbp5.

Socioeconomic Deprivation, Adverse Childhood Experiences and Medical Disorders in Adulthood: Mechanisms and Associations

Severe socioeconomic deprivation (SED) and adverse childhood experiences (ACE) are significantly associated with the development in adulthood of (i) enhanced inflammatory status and/or hypothalamic-pituitary-adrenal (HPA) axis dysfunction and (ii) neurological, neuroprogressive, inflammatory and autoimmune diseases. The mechanisms by which these associations take place are detailed. The two sets of consequences are themselves strongly associated, with the first set likely contributing to the second. Mechanisms enabling bidirectional communication between the immune system and the brain are described, including complex signalling pathways facilitated by factors at the level of immune cells. Also detailed are mechanisms underpinning the association between SED, ACE and the genesis of peripheral inflammation, including epigenetic changes to immune system-related gene expression. The duration and magnitude of inflammatory responses can be influenced by genetic factors, including single nucleotide polymorphisms, and by epigenetic factors, whereby pro-inflammatory cytokines, reactive oxygen species, reactive nitrogen species and nuclear factor-κB affect gene DNA methylation and histone acetylation and also induce several microRNAs including miR-155, miR-181b-1 and miR-146a. Adult HPA axis activity is regulated by (i) genetic factors, such as glucocorticoid receptor polymorphisms; (ii) epigenetic factors affecting glucocorticoid receptor function or expression, including the methylation status of alternative promoter regions of NR3C1 and the methylation of FKBP5 and HSD11β2; (iii) chronic inflammation and chronic nitrosative and oxidative stress. Finally, it is shown how severe psychological stress adversely affects mitochondrial structure and functioning and is associated with changes in brain mitochondrial DNA copy number and transcription; mitochondria can act as couriers of childhood stress into adulthood.

Improvement in cognitive impairment following the successful treatment of endogenous Cushing's syndrome-a case report and literature review

BACKGROUND

Endogenous Cushing's syndrome, a rare endocrine disorder, characterised by chronic cortisol hypersecretion, results in neuropsychiatric disturbances and in cognitive deficits, which are only partially reversible after the biochemical remission of the disease.

CASE PRESENTATION

We report a case of a woman with a profound cognitive deficit and a gradual functional decline caused by Cushing's disease of at least 10 years duration. The neurosurgical resection of her 2 mm adrenocorticotropic hormone (ACTH) secreting pituitary microadenoma resulted in a successful resolution of the patient's hypercortisolism and a significant recovery of her neurocognitive function. The patient's progress was evaluated using serial clinical observations, functional assessments, Mini-Mental Status exams and through the formal neuropsychological report. Furthermore, the patient's recovery of her neurocognitive function was reflected by a sustained improvement in the patient's specific structural brain abnormalities on radiological imaging.

CONCLUSIONS

This report illustrates the importance of early detection and treatment of Cushing's syndrome in order to prevent neurocognitive impairment and neuropsychiatric disorders which are associated with an endogenous cortisol hypersecretion. The long term adverse effects of severe hypercortisolaemia on brain function and the pathophysiological mechanisms responsible for the structural and functional changes in brain anatomy due to glucocorticoid excess are reviewed.

Effect of stress gene-by-environment interactions on hippocampal volumes and cortisol secretion in adolescent girls

OBJECTIVE

Adolescence is a time of increased susceptibility to environmental stress and mood disorders, and girls are particularly at risk. Genes interacting with the environment (G × E) are implicated in hypothalamic-pituitary-adrenal axis dysregulation, hippocampal volume changes and risk or resilience to mood disorders. In this study, we assessed the effects of stress system G × E interactions on hippocampal volumes and cortisol secretion in adolescent girls.

METHODS

We recruited 229 girls aged 12-18 years, and scans were obtained from 202 girls. Of these, 76 had been exposed to higher emotional trauma (abuse or neglect). Hippocampal volumes were measured using Freesurfer and high-resolution structural magnetic resonance imaging scans. Saliva samples were collected for measurement of cortisol levels and genotyping of stress system genes: FKBP5, NR3C1 (both N = 194) and NR3C2 ( N = 193).

RESULTS

Among girls with the 'G' allelic variant of the NR3C1 gene, those who had been exposed to higher emotional trauma had significantly smaller left hippocampal volumes ( N = 44; mean = 4069.58 mm³, standard deviation = 376.99) than girls who had been exposed to minimal emotional trauma with the same allelic variant ( N = 69; mean = 4222.34 mm³, standard deviation = 366.74).

CONCLUSION

In healthy adolescents, interactions between emotional trauma and the 'protective' NR3C1 'GG' variant seem to induce reductions in left hippocampal volumes. These G × E interactions suggest that vulnerability to mood disorders is perhaps driven by reduced 'protection' that may be specific to emotional trauma. This novel but preliminary evidence has implications for targeted prevention of mood disorders and prospective multimodal neuroimaging and longitudinal studies are now needed to investigate this possibility.

Pathophysiology of Glucocorticoid Signaling

Glucocorticoids (GC), such as cortisol or dexamethasone, control various physiological functions, notably those involved in development, metabolism, inflammatory processes and stress, and exert most of their effects upon binding to the glucocorticoid receptor (GR, encoded by NR3C1 gene). GC signaling follows several consecutive steps leading to target gene transactivation, including ligand binding, nuclear translocation of ligand-activated GR complexes, DNA binding, coactivator interaction and recruitment of functional transcriptional machinery. Any step may be impaired and may account for altered GC signaling. Partial or generalized glucocorticoid resistance syndrome may result in a reduced level of functional GR, a decreased hormone affinity and binding, a defect in nuclear GR translocation, a decrease or lack of DNA binding and/or post-transcriptional GR modifications. To date, 26 loss-of-function NR3C1 mutations have been reported in the context of hypertension, hirsutism, adrenal hyperplasia or metabolic disorders. These clinical signs are generally associated with biological features including hypercortisolism without negative regulatory feedback loop on the hypothalamic-pituitary-adrenal axis. Patients had often low plasma aldosterone and renin levels despite hypertension. Only one GR gain-of-function mutation has been described associating Cushing's syndrome phenotype with normal urinary-free cortisol. Some GR polymorphisms (ER22/23EK, GR-9β) have been linked to glucocorticoid resistance and a healthier metabolic profile whereas some others seemed to be associated with GC hypersensitivity (N363S, BclI), increasing cardiovascular risk (diabetes type 2, visceral obesity). This review focuses on the earlier findings on the pathophysiology of GR signaling and presents criteria facilitating identification of novel NR3C1 mutations in selected patients.

BclI polymorphism of the glucocorticoid receptor and adrenal crisis in primary adrenal insufficiency

CONTEXT

Patients with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) are at a high risk of adrenal crisis (AC). Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR).

OBJECTIVES

To determine if a number of intercurrent illnesses and AC are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

This prospective, longitudinal study over 37.7 ± 10.1 months included 47 PAI and 25 CAH patients. During the study period, intercurrent illness episodes and AC were documented.

RESULTS

The study period covered 223 patient years in which 21 AC occurred (9.4 AC/100 pat years). There were no significant differences between BclI polymorphisms (CC (n = 29), CG (n = 34) and GG (n = 9)) regarding BMI, hydrocortisone equivalent daily dose and blood pressure. We did not find a difference in the number of intercurrent illnesses/patient year among BclI polymorphisms (CC (1.5 ± 1.4/pat year), CG (1.2 ± 1.2/pat year) and GG (1.6 ± 2.2/pat year)). The occurrence of AC was not significantly different among the homozygous (GG) genotype (32.5 AC/100 pat years), the CC genotype (6.7 AC/100 pat years) and the CG genotype (4.9 AC/100 pat years). Concomitant hypothyroidism was the highest in the GG genotype group (5/9), compared to others (CC (11/29) and CG (11/34)).

CONCLUSIONS

Although sample sizes were relatively small and results should be interpreted with caution, this study suggests that the GR gene polymorphism BclI may not be associated with the frequencies of intercurrent illnesses and AC.

Glucocorticoid receptor variants in childhood attention-deficit/hyperactivity disorder and comorbid psychiatric disorders

Stress results in a variety of neuroendocrine, immune and behavioral responses and represents a risk factor for many disorders. Following exposure to stress, glucocorticoids are secreted from the adrenal cortex and act via the ligand-activated glucocorticoid receptor (GR). Several polymorphisms of the GR-encoding gene NR3C1 have been described and functionally investigated. However, the impact of these variants on complex diseases such as Attention-Deficit/Hyperactivity Disorder (ADHD) is still unclear. In this study, 251 children with ADHD, 19 affected and 35 unaffected siblings, and their parents were included in a family-based association study assessing seven common variants of NR3C1 (TthIIII_rs10052957; NR3C1-I_rs10482605; ER22/23EK_rs6189/rs6190; N363S_rs56149945; BclI_rs41423247; GR-9beta_rs6198). A four-marker haplotype (TthIIII-NR3C1-I-ER22/23EK) was nominally associated with ADHD. In addition, in index children with ADHD, associations with comorbid disorders, inattentive and hyperactive-impulsive symptoms were explored. N363S minor allele carriers were more likely to show comorbid conduct disorder (CD). In our study, NR3C1 variants moderately affected ADHD and had a significant effect on comorbid CD. Therefore, NR3C1 as an important gene of the hypothalamic-pituitary-adrenal axis seems to be particularly relevant for the pathophysiology of ADHD combined with comorbid CD. For a deeper understanding, investigations in larger samples of healthy, ADHD and CD individuals are warranted.

Role of glutamate receptors and glial cells in the pathophysiology of treatment-resistant depression

Treatment-resistant depression (TRD) causes substantial socioeconomic burden. Although a consensus on the definition of TRD has not yet been reached, it is certain that classic monoaminergic antidepressants are ineffective for TRD. One decade ago, many researchers found ketamine, an N-methyl-d-aspartate receptor (NMDAR) antagonist, to be an alternative to classic monoaminergic antidepressants. The major mechanisms of action of ketamine rapidly induce synaptogenesis in the brain-derived neurotrophic factor (BDNF) pathway. Although excessive glutamatergic neurotransmission and consequent excitotoxicity were considered a major cause of TRD, recent evidence suggests that the extrasynaptic glutamatergic receptor signal pathway mainly contributes to the detrimental effects of TRD. Glial cells such as microglia and astrocytes, early life adversity, and glucocorticoid receptor dysfunction participate in complex cross-talk. An appropriate reuptake of glutamate at the astrocyte is crucial for preventing 'spill-over' of synaptic glutamate and binding to the extrasynaptic NMDA receptor. Excessive microglial activation and the inflammatory process cause astrocyte glutamatergic dysfunction, which in turn activates microglial function. Early life adversity and glucocorticoid receptor dysfunction result in vulnerability to stress in adulthood. A maladaptive response to stress leads to increased glutamatergic release and pro-inflammatory cytokines, which then activate microglia. However, since the role of inflammatory mediators such as pro-inflammatory cytokines is not specific for depression, more disease-specific mechanisms should be identified. Last, although much research has focused on ketamine as an alternative antidepressant for TRD, its long-lasting effectiveness and adverse events have not been rigorously demonstrated. Additionally, evidence suggests that substantial brain abnormalities develop in ketamine abusers. Thus, more investigations for ketamine and other novel glutamatergic agents are needed.

Glucocorticoid Receptor (NR3C1) Variants Associate with the Muscle Strength and Size Response to Resistance Training

Glucocorticoid receptor (NR3C1) polymorphisms associate with obesity, muscle strength, and cortisol sensitivity. We examined associations among four NR3C1 polymorphisms and the muscle response to resistance training (RT). European-American adults (n = 602, 23.8±0.4yr) completed a 12 week unilateral arm RT program. Maximum voluntary contraction (MVC) assessed isometric strength (kg) and MRI assessed biceps size (cm2) pre- and post-resistance training. Subjects were genotyped for NR3C1 -2722G>A, -1887G>A, -1017T>C, and +363A>G. Men carrying the -2722G allele gained less relative MVC (17.3±1.2vs33.5±6.1%) (p = 0.010) than AA homozygotes; men with -1887GG gained greater relative MVC than A allele carriers (19.6±1.4vs13.2±2.3%) (p = 0.016). Women carrying the -1017T allele gained greater relative size (18.7±0.5vs16.1±0.9%) (p = 0.016) than CC homozygotes. We found sex-specific NR3C1 associations with the muscle strength and size response to RT. Future studies should investigate whether these associations are partially explained by cortisol's actions in muscle tissue as they interact with sex differences in cortisol production.

Impact of the glucocorticoid receptor BclI polymorphism on reward expectancy and prediction error related ventral striatal reactivity in depressed and healthy individuals

There is evidence that reward-related neural reactivity is altered in depressive disorders. Glucocorticoids influence dopaminergic transmission, which is widely implicated in reward processing. However, no studies have examined the effect of glucocorticoid receptor gene polymorphisms on reward-related neural reactivity in depressed or healthy individuals. Fifty-nine depressed individuals with major depressive disorder (n=33) or bipolar disorder (n=26), and 32 healthy individuals were genotyped for the glucocorticoid receptor BclI G/C polymorphism, and underwent functional magnetic resonance imaging during a monetary reward task. We examined the effect of the glucocorticoid receptor BclI G/C polymorphism on reward expectancy (RE; expected outcome value) and prediction error (PE; discrepancy between expected and actual outcome) related ventral striatal reactivity. There was a significant interaction between reward condition and BclI genotype (p=0.007). C-allele carriers showed higher PE than RE-related right ventral striatal reactivity (p<0.001), whereas no such difference was observed in G/G homozygotes. Accordingly, C-allele carriers showed a greater difference between PE and RE-related right ventral striatal reactivity than G/G homozygotes (p<0.005), and also showed lower RE-related right ventral striatal reactivity than G/G homozygotes (p=0.011). These findings suggest a slowed transfer from PE to RE-related ventral striatal responses during reinforcement learning in C-allele carriers, regardless of diagnosis, possibly due to altered dopamine release associated with increased sensitivity to glucocorticoids.

Case-control study of glucocorticoid receptor and corticotrophin-releasing hormone receptor gene variants and risk of perinatal depression

Background

Depression during pregnancy or after childbirth is the most frequent perinatal illness affecting women of reproductive age. It could result in unfavourable outcomes for both women and their newborns. The incidence of perinatal depression is higher for those with family history of depression and other mental illness, suggesting the contribution of genetic factors. There is postulation that disruption or fluctuation of reproductive hormones could play a part in women who are sensitive to such changes.

Methods

This is a case-control study comparing the frequencies of candidate gene variants in patients with perinatal depression with controls. Patients of Chinese descent (N = 725) were recruited from the outpatient clinics of the hospital between 2010 and 2013. Controls were patients who came for postnatal consultations at the obstetrics clinics and scored ≤ 7 on the Edinburgh Postnatal Depression Scale (EPDS) at the postnatal screening programme of the hospital. Cases with confirmed diagnosis of clinical (major) depression related to pregnancy/postpartum were recruited from the hospital’s outpatient clinic. Genomic DNA was extracted from saliva samples and genotyped for the polymorphisms of interest. Differences between groups were assessed by chi-square analysis.

Results

CRHR1 rs242939 and rs1876828 were not polymorphic in the study population. There was no statistically significant association of perinatal depression for CRHR1 rs242941 and GR rs41423247 (BclI). When all subjects were grouped based on family history of mental illness, there was a statistically significant association of CRHR1 rs242941 with family history regardless of depression status (P = 0.043). There was also a statistically significant difference for GR rs41423247 and regularity of menstrual periods (P < 0.000). Although not statistically significant, women with perinatal depression showed a trend towards higher frequency of self-reported menstrual irregularity.

Conclusions

No evidence was found for the association of any of the genetic markers with perinatal depression in this study cohort. Instead, the possible genetic links were found in women with positive family history of mental illness and menstrual irregularity, suggesting these could be identifying risk markers for women.

[Molecular-genetic and electroencephalographic markers of neurocognitive processes in depressive disorders]

Perspectives of molecular-genetic approaches to the establishment of mechanisms of development and causes of heterogeneity of neurocognitive impairment are discussed. The current results indicate that candidate genes for depression can contribute to the variance of memory and regulatory functions in patients. At the same time, these genes are closely related to affective information processing and .cortisol level. By that fact, it can't be excluded that affective processes moderate the association between cognition and genes. EEG parameters could be useful phenotypes in the search for and understanding of genetic mechanisms of cognitive deficit in depression. Parameters of resting EEG and its reactive changes are known to reflect the certain cognitive processes. They are influenced by genetic factors and are sensitive indicators of mechanisms that might underlie cognitive impairment in depressive patients. Accumulating data on molecular-genetic correlates of normal electric brain activity may be a source of choosing new candidate genes for cognitive impairment in depression.

Metabolic syndrome in patients with bipolar disorder: comparison with major depressive disorder and non-psychiatric controls

OBJECTIVE

We aimed to investigate the prevalence of the metabolic syndrome (MetS) and its individual components in subjects with bipolar disorder (BD) compared to those with major depressive disorder (MDD) and non-psychiatric controls.

METHODS

We examined 2431 participants (mean age 44.3±13.0, 66.1% female), of whom 241 had BD; 1648 had MDD; and 542 were non-psychiatric controls. The MetS was ascertained according to NCEP ATP III criteria. Multivariable analyses were adjusted for age, sex, ethnicity, level of education, smoking status and severity of depressive symptoms, and in the case of BD subjects, also for psychotropic medication use.

RESULTS

Subjects with BD had a significantly higher prevalence of MetS when compared to subjects with MDD and non-psychiatric controls (28.4% vs. 20.2% and 16.5%, respectively, p<0.001), also when adjusted for sociodemographic and lifestyle factors (OR 1.52, 95% CI: 1.09-2.12, p=0.02 compared to MDD; OR 1.79, 95% CI: 1.20-2.67, p=0.005 compared to non-psychiatric controls). The differences between BD subjects with controls could partly be ascribed to a higher mean waist circumference (91.0 cm vs. 88.8, respectively, p=0.03). In stratified analysis, the differences in the prevalence of MetS between patients with BD and MDD were found in symptomatic but not in asymptomatic cases.

CONCLUSION

This study confirms a higher prevalence of MetS in patients with BD compared to both MDD patients and controls. Specifically at risk are patients with a higher depression score and abdominal obesity.

Is Dysregulation of the HPA-Axis a Core Pathophysiology Mediating Co-Morbid Depression in Neurodegenerative Diseases?

There is increasing evidence of prodromal manifestation of neuropsychiatric symptoms in a variety of neurodegenerative diseases such as Parkinson's disease (PD) and Huntington's disease (HD). These affective symptoms may be observed many years before the core diagnostic symptoms of the neurological condition. It is becoming more apparent that depression is a significant modifying factor of the trajectory of disease progression and even treatment outcomes. It is therefore crucial that we understand the potential pathophysiologies related to the primary condition, which could contribute to the development of depression. The hypothalamic-pituitary-adrenal (HPA)-axis is a key neuroendocrine signaling system involved in physiological homeostasis and stress response. Disturbances of this system lead to severe hormonal imbalances, and the majority of such patients also present with behavioral deficits and/or mood disorders. Dysregulation of the HPA-axis is also strongly implicated in the pathology of major depressive disorder. Consistent with this, antidepressant drugs, such as the selective serotonin reuptake inhibitors have been shown to alter HPA-axis activity. In this review, we will summarize the current state of knowledge regarding HPA-axis pathology in Alzheimer's, PD and HD, differentiating between prodromal and later stages of disease progression when evidence is available. Both clinical and preclinical evidence will be examined, but we highlight animal model studies as being particularly useful for uncovering novel mechanisms of pathology related to co-morbid mood disorders. Finally, we purpose utilizing the preclinical evidence to better inform prospective, intervention studies.

Towards a personalized treatment in depression: endocannabinoids, inflammation and stress response

The complex nature of depression is mirrored by difficulties in tailoring its treatment. Key underlying mechanisms of this mental disorder include elevated inflammation and a dysregulated hypothalamic-pituitary-adrenal (HPA) axis. More recently, the endocannabinoid system has been proposed as another important component in the pathogenesis of depression, and strong evidence suggests that all three systems communicate with each other. A growing number of genetic studies have investigated polymorphisms in depression in each of these systems separately. However, no study to date has looked at these genes in conjunction. In this article we will review the crosstalk between the endocannabinoid system, immune system and HPA axis; and discuss the evidence of gene polymorphisms and their relation to the risk of depression and its treatment. We propose future directions where genes of these three systems are considered from a joint perspective to improve prediction of treatment response, taking into account potentially overlooked genetic variations.

The relationship of serum cortisol levels with depression, cognitive function and sleep disorders in chronic kidney disease and hemodialysis patients

In the present study, the relationships between cortisol, cognitive function, depressive behavior, and sleep quality in chronic kidney disease (CKD) and hemodialysis (HD) patients was investigated. Patients underwent history taking, physical examination, biochemical analysis, 24-h urine collection (for CKD patients only), measurement of dialysis adequacy (for HD patients only), evaluation of cognitive function, depressive behavior and sleep quality. Among study participants 58 had creatinine clearance ≥60 mL/min/1.73 m(2) (Group 1), 41 had creatinine clearance between 30 and 59 mL/min/1.73 m(2) (Group 2), 25 had creatinine clearance between 15 and 29 mL/min/1.73 m(2) (Group 3) and 12 had creatinine clearance <15 mL/min/1.73 m(2) (Group 4). 38 patients were regular HD patients (Group 5). The cortisol levels in Group 1, 2, 3, 4 and 5 patients were 472.3 ± 138.4, 490.2 ± 214.3, 541.6 ± 172.8, 569.9 ± 101.0 and 637.8 ± 153.7 nmol/L, respectively (P < 0.0001 for trend). In both non-dialysis patient group and dialysis patients linear regression analysis showed that cortisol was independently related with Beck depression inventory (BDI) score (P: 0.013 and 0.001, respectively) but not with cognitive function and sleep quality. In conclusion serum cortisol levels were independently associated with depressive behavior both in CKD and HD patients but not with cognitive function and sleep quality.

Mineralocorticoid receptor genotype moderates the association between physical neglect and serum BDNF

The objective of this study is to investigate if a polymorphism in the NR3C2 gene moderates the association between childhood trauma on serum levels of brain derived neurothrophic factor (sBDNF). sBDNF was used here as a general marker of alteration in brain function. This is a community cross sectional study comprising 90 adolescents (54 with anxiety disorders). DNA was extracted from saliva in order to genotype the MR-2G/C (rs2070951) polymorphism using real time PCR. Blood was collected for sBDNF Elisa immunoassay. The Childhood Trauma Questionnaire (CTQ) was used to evaluate childhood abuse and neglect. Main effects and gene environment interactions were tested using linear regression models. Anxiety disorders were not associated with the MR-2G/C polymorphism or with sBDNF levels, but the number of C alleles of the MR-2G/C polymorphism was significantly associated with higher sBDNF levels (b = 8.008; p-value = 0.001). Subjects with intermediate and high exposure to physical neglect showed higher sBDNF levels if compared to subjects non-exposed (b = 11.955; p = 0.004 and b = 16.186; p = 0.009, respectively). In addition, we detected a significant physical neglect by MR-2G/C C allele interaction on sBDNF levels (p = 0.005), meaning that intermediate and high exposure to childhood neglect were only associated with increased sBDNF levels in subjects with the CC genotype, but not in subjects with other genotypes. Our findings suggest that genetic variants in NR3C2 gene may partially explain plastic brain vulnerability to traumatic events. Further studies are needed to investigate the moderating effects of NR3C2 gene in more specific markers of alteration in brain function.

Glucocorticoid receptor polymorphisms and haplotypes and their expression in health and disease

Cortisol is involved in many physiological processes, including immunosuppressive and anti-inflammatory actions, and therefore cortisol and its synthetic analogs are widely used to treat a large number of diseases. In glucocorticoid treatment, a large variability of clinical responses is observed. This variability may, in part, be ascribed to genetic variation in the glucocorticoid receptor (GR) gene. In this review we present a catalogue of the various single nucleotide polymorphisms (SNPs) in the glucocorticoid receptor gene and their consequences for human health and disease. Many different GR SNP association studies have been described. However, most studies come down to only a few SNPs reported with different annotations. In this review we clarified these different annotations to uniform names. Most associations between GR SNPs and phenotype have been found in body composition, metabolism, the cardiovascular system, the immune system and psychiatric illnesses. However, many associations have not been replicated (yet), and future replication studies and meta-analyses are needed. There is a substantial body of evidence for GR SNPs to have effects on clinical phenotype. However, as most SNP frequencies are low and their variation is within the range of the general population, the impact of a single SNP for health and disease in the general population is probably modest. However, in-depth studying of the molecular mechanisms of repeatedly observed clinical associations could lead to new possibilities for drug development. In particular the development of selective glucocorticoid receptor modulators holds promise.

Relationship of the FKBP5 C/T polymorphism with dysfunctional attitudes predisposing to depression

FK506-binding protein 51 (FKBP5) is a co-chaperone of the glucocorticoid receptor, and plays an important role in the negative feedback regulation of the hypothalamic-pituitary-adrenal axis. The C/T single nucleotide polymorphism in the intron 2 of the FKBP5 gene affects cortisol secretion, and has been implicated in the pathophysiology of depression. In this study, the relationship of the FKBP5 C/T polymorphism with dysfunctional attitudes predisposing to depression was examined. The subjects were 300 healthy Japanese. The FKBP5 genotypes were determined by a real-time PCR and cycling probe technology for SNP typing. Dysfunctional attitudes were assessed by the 24-item version of the Dysfunctional Attitude Scale (DAS-24), which has the Achievement, Self-control, and Dependency subscales. DAS-24 total scores were significantly higher in the group with the T allele than in that without this allele (p=0.001). Regarding the subscales, scores of the Achievement (p=0.003) and Self-control (p=0.009) subscales, but not those of the Dependency subscale, were significantly higher in the former group than in the latter group. The present study suggests that the FKBP5 C/T polymorphism is implicated in formation of dysfunctional attitudes, especially those about achievement and self-control.

The multifaceted mineralocorticoid receptor

The primary adrenal cortical steroid hormones, aldosterone, and the glucocorticoids cortisol and corticosterone, act through the structurally similar mineralocorticoid (MR) and glucocorticoid receptors (GRs). Aldosterone is crucial for fluid, electrolyte, and hemodynamic homeostasis and tissue repair; the significantly more abundant glucocorticoids are indispensable for energy homeostasis, appropriate responses to stress, and limiting inflammation. Steroid receptors initiate gene transcription for proteins that effect their actions as well as rapid non-genomic effects through classical cell signaling pathways. GR and MR are expressed in many tissues types, often in the same cells, where they interact at molecular and functional levels, at times in synergy, others in opposition. Thus the appropriate balance of MR and GR activation is crucial for homeostasis. MR has the same binding affinity for aldosterone, cortisol, and corticosterone. Glucocorticoids activate MR in most tissues at basal levels and GR at stress levels. Inactivation of cortisol and corticosterone by 11β-HSD2 allows aldosterone to activate MR within aldosterone target cells and limits activation of the GR. Under most conditions, 11β-HSD1 acts as a reductase and activates cortisol/corticosterone, amplifying circulating levels. 11β-HSD1 and MR antagonists mitigate inappropriate activation of MR under conditions of oxidative stress that contributes to the pathophysiology of the cardiometabolic syndrome; however, MR antagonists decrease normal MR/GR functional interactions, a particular concern for neurons mediating cognition, memory, and affect.

Monosodium glutamate, a food additive, induces depressive-like and anxiogenic-like behaviors in young rats

Monosodium glutamate (MSG) has been the target of research due to its toxicological effects.

AIMS

We investigated the depressive- and anxiogenic-like behaviors in rats exposed to neonatal subcutaneous injection of MSG. The involvement of the serotonergic system, by measuring [(3)H] serotonin (5-HT) uptake in cerebral cortices, and the hypothalamic pituitary adrenal (HPA) axis, by determining serum adrenocorticotropic hormone (ACTH) and corticosterone levels, was also examined.

MATERIALS AND METHODS

Male and female newborn Wistar rats were divided into control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4 g/kg/day) from the 1st to 5th postnatal day. The behavioral tests [spontaneous locomotor activity, contextual fear conditioning, and forced swimming test (FST)] were performed from the 60th to 64th postnatal day. MSG-treated animals showed alteration in the spontaneous locomotor activity, an increase in the number of fecal pellets and the number of animal's vocalizations and urine occurrence, and a decrease in the grooming time.

KEY FINDINGS

The MSG exposure increased the immobility time in the FST and the freezing reaction in the contextual fear conditioning. Additionally, MSG treatment increased the [(3)H]5-HT uptake in the cerebral cortices of rats and induced a deregulation of HPA axis function (by increasing serum ACTH and corticosterone levels).

SIGNIFICANCE

In conclusion MSG-treated rats are more susceptible to develop anxiogenic- and depressive-like behaviors, which could be related to a dysfunction in the serotonergic system.

Association of glucocorticoid and type 1 corticotropin-releasing hormone receptors gene variants and risk for depression during pregnancy and post-partum

Women with postnatal depression (PND) appear to have abnormal hypothalamic pituitary adrenal (HPA) axis responses to stress, which might involve a genetic variability component. We investigated association of genetic variants in the glucocorticoid receptor (GR, NR3C1) and corticotropin releasing hormone receptor 1 (CRHR1) genes with increased risk for PND. Two hundred pregnant women were recruited prospectively and PND risk was assessed by the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy and again 2-8 weeks post-natally (CW-GAPND study). The BclI and ER22/23EK single nucleotide polymorphisms (SNPs) of the GR and the haplotype-tagged rs1876828, rs242939 and rs242941 SNPs of the CRHR1 associated with genetic risk to depressive disorders were genotyped. A cut-off score of 10 was used to detect increased risk of PND. Association analysis was carried out in 140 patients that completed the study protocol. The BclI and rs242939 SNPs were over-represented in women with postnatal EPDS score ≥10 with significant allele association (p = 0.011 and <0.001, respectively) and risk ratios of 2.9 (95% CI: 1.2-6.9) for BclI, 4.9 (2-12) for rs242939 and 5.48 (2.13-14.10) for both. The rs242939 SNP was also associated with increased EPDS values during pregnancy. Moreover, the G-G-T haplotype of the CRHR1 was significantly over-represented in patients with high EPDS scores, with risk ratio of 3.22 (95% CI: 1.91-5.42). This is the first evidence that specific SNPs of genes involved in 'stress' responses might contribute in the genetics of high-risk for depression during pregnancy and postpartum.

Developmental methamphetamine exposure results in short- and long-term alterations in hypothalamic-pituitary-adrenal-axis-associated proteins

Developmental exposure to methamphetamine (MA) causes long-term behavioral and cognitive deficits. One pathway through which MA might induce these deficits is by elevating glucocorticoid levels. Glucocorticoid overexposure during brain development can lead to long-term disruptions in the hypothalamic-pituitary-adrenal (HPA) axis. These disruptions affect the regulation of stress responses and may contribute to behavioral and cognitive deficits reported following developmental MA exposure. Furthermore, alterations in proteins associated with the HPA axis, including vasopressin, oxytocin, and glucocorticoid receptors (GR), are correlated with disruptions in mood and cognition. We therefore hypothesized that early MA exposure will result in short- and long-term alterations in the expression of HPA axis-associated proteins. Male mice were treated with MA (5 mg/kg daily) or saline from postnatal day (P) 11 to P20. At P20 and P90, mice were perfused and their brains processed for vasopressin, oxytocin, and GR immunoreactivity within HPA axis-associated regions. At P20, there was a significant decrease in the number of vasopressin-immunoreactive cells and the area occupied by vasopressin immunoreactivity in the paraventricular nucleus (PVN) of MA-treated mice, but no difference in oxytocin immunoreactivity in the PVN, or GR immunoreactivity in the hippocampus or PVN. In the central nucleus of the amygdala, the area occupied by GR immunoreactivity was decreased by MA. At P90, the number of vasopressin-immunoreactive cells was still decreased, but the area occupied by vasopressin immunoreactivity no longer differed from saline controls. No effects of MA were found on oxytocin or GR immunoreactivity at P90. Thus developmental MA exposure has short- and long-term effects on vasopressin immunoreactivity and short-term effects on GR immunoreactivity.

BclI polymorphism of the glucocorticoid receptor gene is associated with increased bone resorption in patients on glucocorticoid replacement therapy

CONTEXT

Patients with primary adrenal insufficiency (PAI) and patients with congenital adrenal hyperplasia (CAH) receive weight-adapted standard glucocorticoid replacement therapy. Clinically, some patients appear more sensitive to therapeutic administration of glucocorticoids than others. Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR) and might influence bone mineral density (BMD).

OBJECTIVES

To determine if bone turnover markers and BMD are associated with the GR gene polymorphism BclI in patients with PAI and CAH.

DESIGN AND PATIENTS

A prospective, cross-sectional study including 74 PAI and 38 CAH patients. BMD was evaluated by DXA. Serum levels of bone turnover markers, minerals, vitamins and hormones, and urinary crosslinks were measured.

RESULTS

Patients carrying the homozygous BclI polymorphism (GG) had significantly higher serum β-CrossLaps (0.37 ± 0.34 μg/l; P < 0.05) and urinary collagen crosslinks (NTX, 68.1 ± 32.4 nmol/g; P < 0.005) despite receiving the lowest average daily hydrocortisone dose of 9.9 ± 3.7 mg/m(2) (P < 0.05). The GG genotype occurred significantly more frequently in patients with increased NTX (OR=6.7, 95% CI = 1.78-25.38) than in patients with normal NTX. However, BMD was not significantly different between different allelic variants. No significant differences in associations of the genotypes with outcomes (or in clinical characteristics) were found between the sexes.

CONCLUSIONS

Although the sample sizes were relatively small and the results should be interpreted with caution, this study suggests that the homozygous (GG) genotype may be associated with higher bone resorption in adult PAI and CAH patients. GG-carriers needed a lower hydrocortisone dose on average supporting the concept that this GR variant is associated with increased cortisol sensitivity.

Translating the evidence for gene association with depression into mouse models of depression-relevant behaviour: current limitations and future potential

Depression is characterised by high prevalence and complex, heterogeneous psychopathology. At the level of aetio-pathology, considerable research effort has been invested to identify specific gene polymorphisms associated with increased depression prevalence. Genome-wide association studies have not identified any risk polymorphisms, and candidate gene case-control studies have identified a small number of risk polymorphisms. It is increasingly recognised that interaction between genotype and environmental factors (G×E), notably stressful life events, is the more realistic unit of depression aetio-pathology, with G×E evidence described for a small number of risk polymorphisms. An important complementary approach has been to describe genes exhibiting brain region-specific expression changes in depression. Mouse models of depression informed by the human evidence allow for the study of causality, but to-date have also yielded limited insights into depression aetio-pathology. This review of the translational evidence integrates human and mouse research approaches and evidence. It also makes specific recommendations in terms of how future research in human and mouse should be designed in order to deliver evidence for depression aetio-pathology and thereby to inform the development of novel and improved antidepressant treatments.

Epigenetic Modulation of Mood Disorders

BACKGROUND

Mood disorders are expressed in many heterogeneous forms, varying from anxiety to severe major clinical depression. The disorders are expressed in individual variety through manifestations governed by co-morbidities, symptom frequency, severity, and duration, and the effects of genes on phenotypes. The underlying etiologies of mood disorders consist of complex interactive operations of genetic and environmental factors. The notion of endophenotypes, which encompasses the markers of several underlying liabilities to the disorders, may facilitate efforts to detect and define, through staging, the genetic risks inherent to the extreme complexity of disease state.

AIMS

This review evaluates the role of genetic biomarkers in assisting clinical diagnosis, identification of risk factors, and treatment of mood disorders.

METHODS

Through a systematic assessment of studies investigating the epigenetic basis for mood disorders, the present review examines the interaction of genes and environment underlying the pathophysiology of these disorders.

RESULTS

The majority of research findings suggest that the notion of endophenotypes, which encompasses the markers of several underlying liabilities to the disorders, may facilitate efforts to detect and define, through staging, the genetic risks inherent to the extreme complexity of the disease states. Several strategies under development and refinement show the propensity for derivation of essential elements in the etiopathogenesis of the disorders affecting drug-efficacy, drug metabolism, and drug adverse effects, e.g., with regard to selective serotonin reuptake inhibitors. These include: transporter gene expression and genes encoding receptor systems, hypothalamic-pituitary-adrenal axis factors, neurotrophic factors, and inflammatory factors affecting neuroimmune function. Nevertheless, procedural considerations of pharmacogenetics presume the parallel investment of policies and regulations to withstand eventual attempts at misuse, thereby ensuring patient integrity.

CONCLUSIONS

Identification of genetic biomarkers facilitates choice of treatment, prediction of response, and prognosis of outcome over a wide spectrum of symptoms associated with affective states, thereby optimizing clinical practice procedures. Epigenetic regulation of primary brain signaling, e.g., serotonin and hypothalamic-pituitary-adrenal function, and factors governing their metabolism are necessary considerations. The participation of neurotrophic factors remains indispensable for neurogenesis, survival, and functional maintenance of brain systems.

NR3C1 gene polymorphism for genetic susceptibility to infantile spasms in a Chinese population

AIMS

To test the genetic association of NR3C1 gene which encodes the glucocorticoid receptor with infantile spasms (IS).

MAIN METHODS

Nine single nucleotide polymorphisms (SNPs) within the NR3C1 gene were genotyped in a sample set of 128 cases and 131 controls. Association analysis was performed on the genotyped data.

KEY FINDINGS

Two SNPs, rs10482672 and rs2963155, showed nominal associations with IS (P=0.018, OR=1.89, 95% CI=1.11-3.22, for rs10482672; P=0.04, OR=1.70, 95% CI=1.03-2.81 for rs2963155) under the assumption of a dominant model. The haplotype TG of two SNPs (rs6877893 and rs4912905) was associated with a decreased risk of IS (P=0.038, OR=0.66, 95% CI=0.45-0.98), whereas haplotype TC being homozygous was associated with an increased risk of IS (P=0.015, OR=2.60, 95% CI=1.20-5.60). The rs6866893 was also associated with the responsiveness of adrenocorticotropic hormone.

SIGNIFICANCE

The current experimental results suggest the importance of the NR3C1 gene polymorphism for genetic susceptibility to IS in a Chinese population.

Can variation in hypothalamic-pituitary-adrenal (HPA)-axis activity explain the relationship between depression and cognition in bipolar patients?

Background

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is thought to be associated with more mood symptoms and worse cognitive functioning. This study examined whether variation in HPA axis activity underlies the association between mood symptoms and cognitive functioning.

Methodology/Principal Findings

In 65 bipolar patients cognitive functioning was measured in domains of psychomotor speed, speed of information processing, attentional switching, verbal memory, visual memory, executive functioning and an overall mean score. Severity of depression was assessed by the Inventory of Depressive Symptomatology-self rating version. Saliva cortisol measurements were performed to calculate HPA axis indicators: cortisol awakening response, diurnal slope, the evening cortisol level and the cortisol suppression on the dexamethasone suppression test. Regression analyses of depressive symptoms and cognitive functioning on each HPA axis indicator were performed. In addition we calculated percentages explanation of the association between depressive symptoms and cognition by HPA axis indicators. Depressive symptoms were associated with dysfunction in psychomotor speed, attentional switching and the mean score, as well as with attenuation in diurnal slope value. No association was found between HPA axis activity and cognitive functioning and HPA axis activity did not explain the associations between depressive symptoms and cognition.

Conclusions/Significance

As our study is the first one in this field specific for bipolar patients and changes in HPA-axis activity did not seem to explain the association between severity of depressive symptoms and cognitive functioning in bipolar patients, future studies are needed to evaluate other factors that might explain this relationship.

Interaction of the BcII glucocorticoid receptor polymorphism and childhood abuse in Bulimia Nervosa (BN): relationship to BN and to associated trait manifestations

We recently documented a gene-environment interaction suggesting that individuals with Bulimia Nervosa (BN) differed from normal eaters as to the combined presence of the low-function allele of the glucocorticoid receptor polymorphism, BcII, and childhood abuse. The present study examined the extent to which any such interaction effect may have been attributable to behavioral impulsivity, sensation seeking, affective instability or depression. We had 174 bulimic and 130 nonbulimic women provide blood for genetic assays, and measured psychopathological traits and childhood abuse using structured interviews and self-report questionnaires. As expected, we observed a significant BcII × abuse interaction indicating genetic and environmental susceptibilities to co-occur significantly more often in bulimic than in nonbulimic individuals. The BcII × abuse interaction was attenuated when levels of depression were accounted for, but was surprisingly unaffected by controls for motoric impulsivity, sensation seeking or affective instability. Our findings suggest that stress-induced alterations in glucocorticoid sensitivity contribute to BN and depressive disturbances--without being associated with the behavioral/affective dysregulation seen in many BN sufferers. We discuss theoretical and clinical implications of these observations.

Variability in laboratory immune parameters is associated with stress hormone receptor polymorphisms

OBJECTIVES

Interpretation of laboratory immune data in healthy human subjects is often challenging due to wide inter-subject variability. Since endocrine and immune mediators have been mutually interlinked, a potential explanation for the significant variability seen in immune data even when controlled for technical variability and demographics is differences in the binding affinity of ligand with hormone receptors on the surface of immune cells, which can be associated with single nucleotide polymorphisms (SNP).

METHODS

We categorized immunoregulatory cellular profiles from PBMC of 207 healthy volunteers according to glucocorticoid receptor (GR: Bcl1, TthIIII, and A3669G) and β₂-adrenergic receptor (β2AR: Gly16Arg and Gln27Glu) polymorphisms. Subjects were genotyped for each SNP, and Th1, Th2, Th1/Th2 ratio, regulatory T cell (T(reg)), Tr1, and Th3 cell numbers were assessed. Immune parameters in the SNP groups were compared to the wild type (WT).

RESULTS

Significant differences were observed in Th2 and the Th1/Th2 ratio for the β2AR SNP Gly16Arg. Th1, the Th1/Th2 ratio, and Tr1 differed significantly by SNP of Gln27Glu. In addition, the effect of age on Th2 and the effect of the body mass index on the Th1/Th2 ratio significantly differed across subtypes of the Gly16Arg SNP. Significant differences based on allergic status and gender were also seen for T(reg), Th1, and Th2 across Gly16Arg, Gln27Glu, and TthIIII SNP.

CONCLUSIONS

These data suggest that SNP from various components of the stress-immune network may be useful for subgrouping of immune responses to more accurately categorize psychoneuroimmunological components of stress risk in individual subjects. This approach may have significant research and clinical potential.

A randomized trial on mineralocorticoid receptor blockade in men: effects on stress responses, selective attention, and memory

Corticosteroids, released in high amounts after stress, exert their effects via two different receptors in the brain: glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs). GRs have a role in normalizing stress-induced effects and promoting consolidation, while MRs are thought to be important in determining the threshold for activation of the hypothalamic-pituitary-adrenal (HPA) axis. We investigated the effects of MR blockade on HPA axis responses to stress and stress-induced changes in cognitive function. In a double-blind, placebo-controlled study, 64 healthy young men received 400 mg of the MR antagonist spironolactone or placebo. After 1.5 h, they were exposed to either a Trier Social Stress Test or a non-stressful control task. Responses to stress were evaluated by hormonal, subjective, and physiological measurements. Afterwards, selective attention, working memory, and long-term memory performance were assessed. Spironolactone increased basal salivary cortisol levels as well as cortisol levels in response to stress. Furthermore, spironolactone significantly impaired selective attention, but only in the control group. The stress group receiving spironolactone showed impaired working memory performance. By contrast, long-term memory was enhanced in this group. These data support a role of MRs in the regulation of the HPA axis under basal conditions as well as in response to stress. The increased availability of cortisol after spironolactone treatment implies enhanced GR activation, which, in combination with MR blockade, presumably resulted in a decreased MR/GR activation ratio. This condition influences both selective attention and performance in various memory tasks.