Association between GSK-3beta -50T/C polymorphism and personality and psychotic symptoms in mood disorders

Temperament and character dimensions as psychological markers of mood disorders in Polish adolescents and young adults-A prospective study

BACKGROUND

An increasing incidence of mood disorders in adolescents and young adults is being observed. The assessment of personality traits seems to be an interesting tool in identifying early markers of major depression (MD) or bipolar disorder (BD) as well as predictors of the course of the disease. The aim of this study was to compare the personality profiles in young patients with MD and BD in acute and remitted mood states.

METHODS

Seventy-nine adolescents and young adults with mood disorder diagnoses (MD or BD) were included in the study. The participants were assessed based on structured diagnostic interviews and completed the Temperament and Character Inventory (TCI). The clinical evaluation was conducted during the acute episodes and after reaching the stabilized mood in the course of follow-up visits in a 2-year study observation.

RESULTS

At baseline, MD patients had higher scores on the harm avoidance (HA) with more pronounced anticipatory worry and fatigability subscale than BD patients. Conversely, BD patients reached higher scores in the total self-directedness (SD) character dimension and its sub-dimensions. MD patients with acute depressive symptoms had higher scores in the HA dimension and its subscale: anticipatory worry, shyness, and fatigability compared with their euthymic states. No significant differences in TCI dimensions between baseline and euthymia in the BD subgroup were found, and no differences between euthymic MD and BD patients.

CONCLUSIONS

Higher ST and SD sub-dimensions may constitute a personality profile specific to BD, while high HA seems to be related to major depression in both acute and remitted states in young patients.

Serotonin 5-HT2A receptor polymorphisms are associated with irritability and aggression in conduct disorder

In childhood and adolescence, overt antisocial and aggressive manifestations are typically diagnosed as conduct disorder (CD). Given that the emerging research has pointed to the influence of 5-HT_2A receptors in the ontogeny of aggression, we aimed to analyze the association of its genetic polymorphisms with CD. The study included 228 male adolescent subjects (120 with and 108 without CD). CD was diagnosed according to Structured Clinical Interview for DSM-IV criteria, while evaluations of aggressive/dissociative behaviors were performed using psychometric questionnaires including the PCL-YV, OAS-M, KADS, and CBCL. Platelet 5-HT concentration was determined by spectrophotofluorometry. Genotyping of 5-HT_2A receptor polymorphisms rs2070040, rs9534511, rs4142900, rs9534512 was performed using TaqMan SNP Genotyping Assays. Subjective irritability, physical aggression toward others, and antisocial behavior were strongly associated with the G allele of rs2070040 and rs4142900, and the C allele of rs9534511 and rs9534512. A significantly increased platelet 5-HT concentration in CD subjects, compared to controls, was lost after the correction according to the smoking status. Our results indicate an association of the studied HTR2A polymorphisms and their haplotypes with irritability and impulsivity traits, which may contribute to the aggressive and antisocial behavior in male adolescents with CD.

The role of alcohol intake in the pharmacogenetics of treatment with clozapine

Clozapine (CLZ) is an atypical antipsychotic reserved for patients with refractory psychosis, but it is associated with a significant risk of severe adverse reactions (ADRs) that are potentiated with the concomitant use of alcohol. Additionally, pharmacogenetic studies have explored the influence of several genetic variants in CYP450, receptors and transporters involved in the interindividual response to CLZ. Herein, we systematically review the current multiomics knowledge behind the interaction between CLZ and alcohol intake, and how its concomitant use might modulate the pharmacogenetics. CYP1A2*1F, *1C and other alleles not yet discovered could support a precision medicine approach for better therapeutic effects and fewer CLZ ADRs. CLZ monitoring systems should be amended and include alcohol intake to protect patients from severe CLZ ADRs.

Association study of six candidate genes with major depressive disorder in the North-Western population of Pakistan

People around the world are currently affected by Major Depressive Disorder (MDD). Despite its many aspects, symptoms, manifestations and impacts, efforts have been made to identify the root causes of the disorder. In particular, genetic studies have concentrated on identifying candidate genes for MDD and exploring associations between these genes and some specific group of individuals. The aim of this research was to find out the association between single nucleotide polymorphisms in 6 candidate genes linked to the neurobiology of major depressive disorder in the North-Western population of Pakistan. We performed a case-control analysis, with 400 MDD and 232 controls. A trained psychiatrist or clinical psychologists evaluated the patients. Six polymorphisms were genotyped and tested for allele and genotype association with MDD. There were no statistical variations between MDD patients and healthy controls for genotypic and allelic distribution of all the polymorphisms observed. Thus, our analysis does not support the major role of these polymorphisms in contributing to MDD susceptibility, although it does not preclude minor impact. The statistically significant correlation between six polymorphisms and major depressive disorder in the studied population was not observed. There are inconsistencies in investigations around the world. Future research, including GWAS and association analysis on larger scale should be addressed for further validation and replication of the present findings.

Deletion or inhibition of prolyl oligopeptidase blocks lithium-induced phosphorylation of GSK3b and Akt by activation of protein phosphatase 2A

Alterations in prolyl oligopeptidase (PREP) activity have been connected, for example, with bipolar and major depressive disorder, and several studies have reported that lack or inhibition of PREP blocks the effects of lithium on inositol 1,4,5-triphosphate (IP₃ ) levels. However, the impact of PREP modulation on other intracellular targets of lithium, such as glycogen synthase kinase 3 beta (GSK3b) or protein kinase B (Akt), has not been studied. We recently found that PREP regulates protein phosphatase 2A (PP2A), and because GSK3b and Akt are PP2A substrates, we studied if PREP-related lithium insensitivity is dependent on PP2A. To assess this, HEK-293 and SH-SY5Y cells with PREP deletion or PREP inhibition (KYP-2047) were exposed to lithium, and thereafter, the phosphorylation levels of GSK3b and Akt were measured by Western blot. As expected, PREP deletion and inhibition blocked the lithium-induced phosphorylation on GSK3b and Akt in both cell lines. When lithium exposure was combined with okadaic acid, a PP2A inhibitor, KYP-2047 did not have effect on lithium-induced GSK3b and Akt phosphorylation. Therefore, we conclude that PREP deletion or inhibition blocks the intracellular effects of lithium on GSK3b and Akt via PP2A activation.

Glycogen synthase kinase-3ß supports serotonin transporter function and trafficking in a phosphorylation-dependent manner

Serotonin (5-HT) transporter (SERT) plays a crucial role in serotonergic transmission in the central nervous system, and any aberration causes serious mental illnesses. Nevertheless, the cellular mechanisms that regulate SERT function and trafficking are not entirely understood. Growing evidence suggests that several protein kinases act as modulators. Here, we delineate the molecular mechanisms by which glycogen synthase kinase-3ß (GSK3ß) regulates SERT. When mouse striatal synaptosomes were treated with the GSK3α/ß inhibitor CHIR99021, we observed a significant increase in SERT function, V_max , surface expression with a reduction in 5-HT K_m and SERT phosphorylation. To further study how the SERT molecule is affected by GSK3α/ß, we used HEK-293 cells as a heterologous expression system. As in striatal synaptosomes, CHIR99021 treatment of cells expressing wild-type hSERT (hSERT-WT) resulted in a time and dose-dependent elevation of hSERT function with a concomitant increase in the V_max and surface transporters because of reduced internalization and enhanced membrane insertion; silencing GSK3α/ß in these cells with siRNA also similarly affected hSERT. Converting putative GSK3α/ß phosphorylation site serine at position 48 to alanine in hSERT (hSERT-S48A) completely abrogated the effects of both the inhibitor CHIR99021 and GSK3α/ß siRNA. Substantiating these findings, over-expression of constitutively active GSK3ß with hSERT-WT, but not with hSERT-S48A, reduced SERT function, V_max , surface density, and enhanced transporter phosphorylation. Both hSERT-WT and hSERT-S48A were inhibited similarly by PKC activation or by inhibition of Akt, CaMKII, p38 MAPK, or Src kinase. These findings provide new evidence that GSK3ß supports basal SERT function and trafficking via serine-48 phosphorylation.

Temperament and character influence on depression treatment outcome

BACKGROUND

personality features have been repeatedly associated with depression treatment outcome in Major Depressive Disorder (MDD), however conclusive results are still lacking. Moreover, as for Bipolar Disorder (BD), results are only few and preliminary.

AIM

the aim of the present study was to perform an exploratory investigation of the influence of personality traits as assessed by the Temperament and Character Inventory (TCI), on principal depression treatment outcomes (non remission, non response and resistance).

METHODS

743 mood disorders patients (455 MDD (61.24%) and 288 BD (38.76%)) were recruited in the context of 6 European studies. Generalized logit models were performed to test the effects of TCI dimensions on treatment outcomes, considering possible confounders such as age, gender and education. Positive results were controlled for comorbidities (anxiety and substance use disorders) as well.

RESULTS

MDD Non-Remitters showed high Harm Avoidance (HA) and Self Transcendence (ST) (p = 0.0004, d = 0.40; p = 0.007, d = 0.36 respectively) and low Persistence (P) and Self Directedness (SD) (p = 0.05; d = 0.18; p = 0.002, d = 0.40, respectively); MDD Non-Responders showed a slightly different profile with high HA and low Reward Dependence (RD) and SD; finally, MDD Resistants showed low RD, P and Cooperativeness (C). In BD patients, only higher HA in non response was observed.

LIMITATIONS

the retrospective cross-sectional design, the TCI assessment regardless of the mood state and the small number of bipolar patients represent the main limitations.

CONCLUSION

specific TCI personality traits are associated with depression treatment outcome in MDD patients. The inclusion of such personality traits, together with other socio-demographic and clinical predictors, could ameliorate the accuracy of the prediction models available to date.

Bromide alleviates fatty acid-induced lipid accumulation in mouse primary hepatocytes through the activation of PPARα signals

Increased plasma free fatty acids (FFAs) and liver triglyceride (TG) accumulations have been implicated in the pathogenesis of hepatic steatosis. On the other hand, trace elements function as essential cofactors that are involved in various biochemical processes in mammals, including metabolic homeostasis. Notably, clinical and animal studies suggest that the plasma levels of bromide negatively correlate with those of TG, total cholesterol (TC) and high‐density lipoprotein‐cholesterol (HDL‐C). However, the effect of bromide on lipid accumulation and the direct molecular target responsible for its action remains unknown. Oil red O (ORO) and Nile red staining were used to detect the effect of bromide on lipid accumulation in mouse primary hepatocytes (PHs) treated with different doses of sodium bromide (NaBr) in the presence of FFAs (0.4 mM oleate/palmitic acid 1:1). Spectrophotometric and fluorometric analyses were performed to assess cellular TG concentrations and rates of fatty acid oxidation (FAO), respectively, in mouse PHs. We found that bromide decreased FFA‐induced lipid accumulation and increased FFA‐inhibited oxygen consumptions in mouse PHs in a dose‐dependent manner via activation of PPARα. Mechanical studies demonstrated that bromide decreased the phosphorylation levels of JNK. More importantly, the PPARα‐specific inhibitor GW6471 partially abolished the beneficial effects of bromide on mouse PHs. Bromide alleviates FFA‐induced excessive lipid storage and increases rates of FAO through the activation of PPARα/JNK signals in mouse PHs. Therefore, bromide may serve as a novel drug in the treatment of hepatic steatosis.

GSK3β: a plausible mechanism of cognitive and hippocampal changes induced by erythropoietin treatment in mood disorders?

Mood disorders are associated with significant psychosocial and occupational disability. It is estimated that major depressive disorder (MDD) will become the second leading cause of disability worldwide by 2020. Existing pharmacological and psychological treatments are limited for targeting cognitive dysfunctions in mood disorders. However, growing evidence from human and animal studies has shown that treatment with erythropoietin (EPO) can improve cognitive function. A recent study involving EPO-treated patients with mood disorders showed that the neural basis for their cognitive improvements appeared to involve an increase in hippocampal volume. Molecular mechanisms underlying hippocampal changes have been proposed, including the activation of anti-apoptotic, antioxidant, pro-survival and anti-inflammatory signalling pathways. The aim of this review is to describe the potential importance of glycogen synthase kinase 3-beta (GSK3β) as a multi-potent molecular mechanism of EPO-induced hippocampal volume change in mood disorder patients. We first examine published associations between EPO administration, mood disorders, cognition and hippocampal volume. We then highlight evidence suggesting that GSK3β influences hippocampal volume in MDD patients, and how this could assist with targeting more precise treatments particularly for cognitive deficits in patients with mood disorders. We conclude by suggesting how this developing area of research can be further advanced, such as using pharmacogenetic studies of EPO treatment in patients with mood disorders.

Neuroplasticity, Neurotransmission and Brain-Related Genes in Major Depression and Bipolar Disorder: Focus on Treatment Outcomes in an Asiatic Sample

INTRODUCTION

Mood disorders are common and disabling disorders. Despite the availability of over 100 psychotropic compounds, only one-third of patients benefit from first-line treatments. Over the past 20 years, many studies have focused on the biological factors modulating disease risk and response to treatments, but with still inconclusive data. In order to improve our current knowledge, in this study, we investigated the role of a set of genes involved in different pathways (neurotransmission, neuroplasticity, circadian rhythms, transcription factors, signal transduction and cellular metabolism) in the treatment outcome of major depressive disorder (MDD) and bipolar disorder (BD) after naturalistic pharmacological treatment.

METHODS

Totals of 242 MDD, 132 BD patients and 326 healthy controls of Asian ethnicity (Koreans) were genotyped for polymorphisms within 19 genes. Response and remission after 6-8 weeks of treatment with antidepressants and mood stabilizers were evaluated. In secondary analyses, genetic associations with disease risk and some disease-associated features (age of onset, suicide attempt and psychotic BD) were also tested.

RESULTS

None of the variants within the investigated genes was significantly associated with treatment outcomes. Some marginal association (uncorrected p < 0.01) was observed for HTR2A, BDNF, CHL1, RORA and HOMER1 SNPs. In secondary analyses, HTR2A (rs643627, p = 0.002) and CHL1 (rs4003413, p = 0.002) were found associated with risk for BD, HOMER1 (rs6872497, p = 0.002) with lifetime history of suicide attempt in patients, and RORA with early onset and presence of psychotic features in BD. Marginal results were also observed for ST8SIA2 and COMT.

DISCUSSION

Despite limitations linked to multiple testing on small samples, methodological shortcomings and small significance of the findings, this study may support the involvement of some candidate genes in the outcomes of treatments for mood disorders, as well as in BD risk and other disease features.

An Oldie but Goodie: Lithium in the Treatment of Bipolar Disorder through Neuroprotective and Neurotrophic Mechanisms

Lithium has been used for the treatment of bipolar disorder (BD) for the last sixty or more years, and recent studies with more reliable designs and updated guidelines have recommended lithium to be the treatment of choice for acute manic, mixed and depressive episodes of BD, along with long-term prophylaxis. Lithium’s specific mechanism of action in mood regulation is progressively being clarified, such as the direct inhibition on glycogen synthase kinase 3β, and its various effects on neurotrophic factors, neurotransmitters, oxidative metabolism, apoptosis, second messenger systems, and biological systems are also being revealed. Furthermore, lithium has been proposed to exert its treatment effects through mechanisms associated with neuronal plasticity. In this review, we have overviewed the clinical aspects of lithium use for BD, and have focused on the neuroprotective and neurotrophic effects of lithium.

Association between neurological soft signs, temperament and character in patients with schizophrenia and non-psychotic relatives

The heritability of schizophrenia and most personality traits has been well established, but the role of personality in susceptibility to schizophrenia remains uncertain. The aim of this study was to test for an association between personality traits and Neurological Soft Signs (NSS), a well-known biological marker of schizophrenia, in non-psychotic relatives of patients with schizophrenia. For this purpose, we evaluated the NSS scale and personality measured by the Temperament and Character inventory (TCI-R) in three groups of subjects: 29 patients with schizophrenia, 24 unaffected relatives and 37 controls. The results showed that patients with schizophrenia were more asocial (higher harm avoidance and lower reward dependence), more perseverative (higher persistence), and more schizotypal (lower self-directedness and cooperativeness, higher self-transcendence). The unaffected relatives showed higher harm avoidance, lower self-directedness and cooperativeness than the healthy controls. Higher NSS scores and sub-scores were found in patients and non-psychotic relatives compared with the controls. Among all the patients, total NSS scores were positively correlated with harm avoidance but negatively correlated with novelty seeking and persistence. Total NSS were also correlated with low scores on self-directedness and cooperativeness, which are indicators of personality disorder. Our results show that susceptibility to NSS and to schizophrenia are both related to individual differences in the temperament and character features in non-psychotic relatives of patients with schizophrenia. High harm avoidance, low persistence, low self-directedness and low cooperativeness contribute to both the risk of NSS and schizophrenia. These findings highlight the value of using both assessments to study high risk populations.

Akt-mediated regulation of antidepressant-sensitive serotonin transporter function, cell-surface expression and phosphorylation

The present study is focused on the cellular basis for Akt-mediated SERT regulation. SERT has been implicated in mood disorders. SERT is a primary target for antidepressants used in the therapeutic intervention of psychiatric disorders.

The emerging role of dopamine-glutamate interaction and of the postsynaptic density in bipolar disorder pathophysiology: Implications for treatment

Aberrant synaptic plasticity, originating from abnormalities in dopamine and/or glutamate transduction pathways, may contribute to the complex clinical manifestations of bipolar disorder (BD). Dopamine and glutamate systems cross-talk at multiple levels, such as at the postsynaptic density (PSD). The PSD is a structural and functional protein mesh implicated in dopamine and glutamate-mediated synaptic plasticity. Proteins at PSD have been demonstrated to be involved in mood disorders pathophysiology and to be modulated by antipsychotics and mood stabilizers. On the other side, post-receptor effectors such as protein kinase B (Akt), glycogen synthase kinase-3 (GSK-3) and the extracellular signal-regulated kinase (Erk), which are implicated in both molecular abnormalities and treatment of BD, may interact with PSD proteins, and participate in the interplay of the dopamine-glutamate signalling pathway. In this review, we describe emerging evidence on the molecular cross-talk between dopamine and glutamate signalling in BD pathophysiology and pharmacological treatment, mainly focusing on dysfunctions in PSD molecules. We also aim to discuss future therapeutic strategies that could selectively target the PSD-mediated signalling cascade at the crossroads of dopamine-glutamate neurotransmission.

Genetic variant of AKT1 and AKTIP associated with late-onset depression in a Brazilian population

OBJECTIVES

Examine the association between polymorphisms in the AKT1 and AKTIP genes and late-onset depression (LOD). Major depressive disorder is one of the most prevalent neuropsychiatric diseases. LOD is a disorder that starts after 65 years old. AKT1 is a downstream enzyme that has been implicated in the pathogenesis of neurotransmitter-related disorders, such as depression. The identification of a novel AKT1-binding protein (AKTIP) was pointed as an important new target. AKTIP binds directly to AKT1, enhancing the phosphorylation of regulatory sites, and this modulation are affected by AKT1 activation. The association of AKT1 and AKTIP polymorphisms with depressive symptoms was not investigated in LOD.

DESIGN

Genotype tagSNPs in the AKT1 and AKTIP in LOD patients and controls.

SETTINGS

An academic medical center.

PARTICIPANTS

Sample composed by 190 outpatients with LOD and 77 healthy individuals.

MEASURES

The participants were evaluated using Diagnostic and Statistical Manual IV criteria, MINI-PLUS and the Geriatric Depression Scale.

RESULTS

Our findings suggested an association between the tagSNP rs3730358 homozygous A/A (p = 0.006) and LOD. A strong association of allele A and increased association for LOD was demonstrated with tagSNP rs3730358 (p-value = 0.003).

LIMITATIONS

Limitation include composition of our control group, where the exclusion criteria generated a kind of super-healthy older group what might have produced a hidden stratification when compared with the LOD.

CONCLUSION

This study is the first one to establish the association of the AKT1/AKTIP genes and LOD, and further studies are necessary to clarify the functional role of these proteins.

Integrated neurobiology of bipolar disorder

From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity - reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition - limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional "unified field theory" of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia - the brain's primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the hypothalamic-pituitary-adrenal axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway, or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great questions facing the field and one that is likely to have profound treatment implications, given that fact that such a discovery would greatly increase our ability to individualize - and by extension, enhance - treatment.

Clinical and molecular genetics of psychotic depression

This review provides a comprehensive overview of clinical and molecular genetic as well as pharmacogenetic studies regarding the clinical phenotype of "psychotic depression." Results are discussed with regard to the long-standing debate on categorical vs dimensional disease models of affective and psychotic disorders on a continuum from unipolar depression over bipolar disorder and schizoaffective disorder to schizophrenia. Clinical genetic studies suggest a familial aggregation and a considerable heritability (39%) of psychotic depression partly shared with schizoaffective disorder, schizophrenia, and affective disorders. Molecular genetic studies point to potential risk loci of psychotic depression shared with schizoaffective disorder (1q42, 22q11, 19p13), depression, bipolar disorder, and schizophrenia (6p, 8p22, 10p13-12, 10p14, 13q13-14, 13q32, 18p, 22q11-13) and several vulnerability genes possibly contributing to an increased risk of psychotic symptoms in depression (eg, BDNF, DBH, DTNBP1, DRD2, DRD4, GSK-3beta, MAO-A). Pharmacogenetic studies implicate 5-HTT, TPH1, and DTNBP1 gene variation in the mediation of antidepressant treatment response in psychotic depression. Genetic factors are suggested to contribute to the disease risk of psychotic depression in partial overlap with disorders along the affective-psychotic spectrum. Thus, genetic research focusing on psychotic depression might inspire a more dimensional, neurobiologically and symptom-oriented taxonomy of affective and psychotic disorders challenging the dichotomous Kraepelinian view. Additionally, pharmacogenetic studies might aid in the development of a more personalized treatment of psychotic depression with an individually tailored antidepressive/antipsychotic pharmacotherapy according to genotype.

Inhibition of GSK3 by lithium, from single molecules to signaling networks

For more than 60 years, the mood stabilizer lithium has been used alone or in combination for the treatment of bipolar disorder, schizophrenia, depression, and other mental illnesses. Despite this long history, the molecular mechanisms trough which lithium regulates behavior are still poorly understood. Among several targets, lithium has been shown to directly inhibit glycogen synthase kinase 3 alpha and beta (GSK3α and GSK3β). However in vivo, lithium also inhibits GSK3 by regulating other mechanisms like the formation of a signaling complex comprised of beta-arrestin 2 (βArr2) and Akt. Here, we provide an overview of in vivo evidence supporting a role for inhibition of GSK3 in some behavioral effects of lithium. We also explore how regulation of GSK3 by lithium within a signaling network involving several molecular targets and cell surface receptors [e.g., G protein coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs)] may provide cues to its relative pharmacological selectivity and its effects on disease mechanisms. A better understanding of these intricate actions of lithium at a systems level may allow the rational development of better mood stabilizer drugs with enhanced selectivity, efficacy, and lesser side effects.

Genome-wide association study of personality traits in bipolar patients

OBJECTIVE

Genome-wide association study was carried out on personality traits among bipolar patients as possible endophenotypes for gene discovery in bipolar disorder.

METHODS

The subscales of Cloninger's Temperament and Character Inventory (TCI) and the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) were used as quantitative phenotypes. The genotyping platform was the Affymetrix 6.0 SNP array. The sample consisted of 944 individuals for TCI and 1007 for ZKPQ, all of European ancestry, diagnosed with bipolar disorder by Diagnostic and Statistical Manual of Mental Disorders-IV criteria.

RESULTS

Genome-wide significant association was found for two subscales of the TCI, rs10479334 with the 'Social Acceptance versus Social Intolerance' subscale (Bonferroni P = 0.014) in an intergenic region, and rs9419788 with the 'Spiritual Acceptance versus Rational Materialism' subscale (Bonferroni P = 0.036) in PLCE1 gene. Although genome-wide significance was not reached for ZKPQ scales, lowest P values pinpointed to genes, RXRG for Sensation Seeking, GRM7 and ITK for Neuroticism Anxiety, and SPTLC3 gene for Aggression Hostility.

CONCLUSION

After correction for the 25 subscales in TCI and four scales plus two subscales in ZKPQ, phenotype-wide significance was not reached.

Effect of a chronic treatment with 17β-estradiol on striatal dopamine neurotransmission and the Akt/GSK3 signaling pathway in the brain of ovariectomized monkeys

The present experiments sought the effect of chronic treatment with 17β-estradiol on striatal dopaminergic activity and the Akt/GSK3 signaling pathway in the brain of monkeys. Eight female monkeys (Macacca fascicularis) were ovariectomized (OVX) and a month later, half received a month treatment with 17β-estradiol and the other with vehicle. The DA transporter (DAT) was measured by autoradiography with [(125)I]RTI-121 and the vesicular DA transporter (VMAT(2)) with [(3)H]TBZ-OH at three rostro-caudal levels (anterior, middle and posterior) of the caudate nucleus and putamen subdivided in their lateral/medial, ventral/dorsal sub-regions. Specific binding to DAT was increased in all sub-regions of the caudate nucleus and the putamen of 17β-estradiol-treated compared to vehicle-treated monkeys whereas specific binding to VMAT(2) remained unchanged. We measured by Western blot the phosphorylated forms of Akt at serine 473 and threonine 308, GSK3β at serine 9 and tyrosine 216 and GSK3α at serine 21 in anterior, middle and posterior caudate nucleus and putamen. 17β-Estradiol treatment increased in all the caudate nucleus and putamen pAkt (Ser473)/βIII-tubulin, pGSK3β (Ser9)/βIII-tubulin and in putamen Akt/βIII-tubulin compared to vehicle-treated monkeys. In anterior and middle putamen, pAkt (Thr308)/βIII-tubulin was also increased in monkeys treated with 17β-estradiol. pGSK3β (Tyr216)/βIII-tubulin and pGSK3α (Ser21)/βIII-tubulin remained unchanged by the 17β-estradiol treatment. These results suggest that 17β-estradiol activates striatal DA neurotransmission in primates as reflected with increased DAT specific binding and downstream activation of Akt/GSK3 signaling. This supports a beneficial role of a chronic treatment with 17β-estradiol by increasing the activity of signaling pathways implicated in cell survival.

ANK3, CACNA1C and ZNF804A gene variants in bipolar disorders and psychosis subphenotype

OBJECTIVES. The ANK3, CACNA1C and ZNF804A genes have been implicated in both bipolar disorders (BPD) and schizophrenia (SCZ). It has been suggested that BPD with psychosis may be a clinical manifestation of genes overlapping between BPD and SCZ. We therefore tested the association of these genes with BPD in a large family-based sample, and then dissected the phenotype into psychosis present or absent subgroups. METHODS. We genotyped four high interest single nucleotide polymorphisms from ANK3 (rs10994336, rs9804190), CACNA1C (rs1006737), and ZNF804A (rs1344706). Family based association testing (FBAT) was performed on 312 families, and within psychotic (N = 158) and non-psychotic BPD (N = 119) subgroups. RESULTS. In the whole sample, we found a nominal association in ZNF804A (rs1344706, P = 0.046), and a trend in CACNA1C (rs1006737, P = 0.077). In the psychotic BPD subgroup, as hypothesized, stronger signals were observed in ZNF804A (P = 0.019) and CACNA1C (P = 0.017). We found no association in the ANK3 markers, but the rs10994336 variant was nominally associated with non-psychotic BPD (P = 0.046). Exploratory analysis revealed the rs1344706 variant was also implicated in suicide-attempt behaviour (P = 0.038). CONCLUSIONS. These tentative results are consistent with the hypothesis that the subphenotype of BPD with psychosis may represent a clinical manifestation of shared genetic liability between BPD and SCZ.

The impact of glycogen synthase kinase 3β gene on psychotic mania in bipolar disorder patients

OBJECTIVE

The aim of this study was to examine the relationships between glycogen synthase 3β gene polymorphisms and bipolar I disorder, manic in a Korean sample.

METHODS

Patients with bipolar disorder (n=118) and a control group (n=158) were assessed by genotyping for GSK3β single nucleotide polymorphisms (SNPs) -1727A/T and -50C/T. The patients were divided into two groups according to the presence of psychotic symptoms (psychotic mania, n=92; non-psychotic mania, n=26) and also divided based on gender and age of onset. The severity of symptoms was measured using the Young Mania Rating Scale (YMRS) and the Brief Psychiatric Rating Scale (BPRS).

RESULTS

There were no significant differences in the genotype distributions or allelic frequencies of GSK3β polymorphisms and gender between patients with bipolar disorder and a normal control group. According to haplotype analysis, there was no association between these two groups. However, analysis of the age of onset of bipolar disorder revealed significant differences in genotype and allele distributions among the patients. Patients who were homozygous for the wild-type variant (TT) had an older age of onset than carriers of the mutant allele (A/A: 27.4±9.1; A/T: 30.1±11.8; T/T: 42.3±19.9; p=0.034). We detected differences in allele frequencies of the GSK3β -1727A/T polymorphism between the psychotic mania group and the non-psychotic mania group.

CONCLUSION

This study suggests that GSK3β polymorphisms are not associated with bipolar disorder. However, the GSK3β SNP -1727A/T is associated with age of onset and presence of psychotic symptoms in bipolar disorder.

Dysbindin (DTNBP1)--a role in psychotic depression?

Previous studies yielded evidence for dysbindin (DTNBP1) to impact the pathogenesis of schizophrenia on the one hand and affective disorders such as bipolar or major depressive disorder (MDD) on the other. Thus, in the present study we investigated whether DTNBP1 variation was associated with psychotic depression as a severe clinical manifestation of MDD possibly constituting an overlapping phenotype between affective disorders and schizophrenia. A sample of 243 Caucasian inpatients with MDD (SCID-I) was genotyped for 12 SNPs spanning 92% of the DTNBP1 gene region. Differences in DTNBP1 genotype distributions across diagnostic subgroups of psychotic (N = 131) vs. non-psychotic depression were estimated by Pearson Chi(2) test and logistic regression analyses adjusted for age, gender, Beck Depression Inventory (BDI) and the Global Assessment of Functioning Scale (GAF). Overall, patients with psychotic depression presented with higher BDI and lower GAF scores expressing a higher severity of the illness as compared to depressed patients without psychotic features. Four DTNBP1 SNPs, particularly rs1997679 and rs9370822, and the corresponding haplotypes, respectively, were found to be significantly associated with the risk of psychotic depression in an allele-dose fashion. In summary, the present results provide preliminary support for dysbindin (DTNBP1) gene variation, particularly SNPs rs1997679 and rs9370822, to be associated with the clinical phenotype of psychotic depression suggesting a possible neurobiological mechanism for an intermediate trait on the continuum between affective disorders and schizophrenia.

Mutant DISC1 affects methamphetamine-induced sensitization and conditioned place preference: a comorbidity model

Genetic factors involved in neuroplasticity have been implicated in major psychiatric illnesses such as schizophrenia, depression, and substance abuse. Given its extended interactome, variants in the Disrupted-In-Schizophrenia-1 (DISC1) gene could contribute to drug addiction and psychiatric diseases. Thus, we evaluated how dominant-negative mutant DISC1 influenced the neurobehavioral and molecular effects of methamphetamine (METH). Control and mutant DISC1 mice were studied before or after treatment with non-toxic escalating dose (ED) of METH. In naïve mice, we assessed METH-induced conditioned place preference (CPP), dopamine (DA) D2 receptor density and the basal and METH-induced activity of DISC1 partners, AKT and GSK-3β in the ventral striatum. In ED-treated mice, 4 weeks after METH treatment, we evaluated fear conditioning, depression-like responses in forced swim test, and the basal and METH-induced activity of AKT and GSK-3β in the ventral striatum. We found impairment in METH-induced CPP, decreased DA D2 receptor density and altered METH-induced phosphorylation of AKT and GSK-3β in naïve DISC1 female mice. The ED regimen was not neurotoxic as evidenced by unaltered brain regional monoamine tissue content. Mutant DISC1 significantly delayed METH ED-produced sensitization and affected drug-induced phosphorylation of AKT and GSK-3β in female mice. Our results suggest that perturbations in DISC1 functions in the ventral striatum may impact the molecular mechanisms of reward and sensitization, contributing to comorbidity between drug abuse and major mental diseases.

Bipolar Disorder and the TCI: Higher Self-Transcendence in Bipolar Disorder Compared to Major Depression

Personality traits are potential endophenotypes for genetic studies of psychiatric disorders. One personality theory which demonstrates strong heritability is Cloninger's psychobiological model measured using the temperament and character inventory (TCI). 277 individuals who completed the TCI questionnaire as part of the South Island Bipolar Study were also interviewed to assess for lifetime psychiatric diagnoses. Four groups were compared, bipolar disorder (BP), type 1 and 2, MDD (major depressive disorder), and nonaffected relatives of a proband with BP. With correction for mood state, total harm avoidance (HA) was higher than unaffected in both MDD and BP groups, but the mood disorder groups did not differ from each other. However, BP1 individuals had higher self-transcendence (ST) than those with MDD and unaffected relatives. HA may reflect a trait marker of mood disorders whereas high ST may be specific to BP. As ST is heritable, genes that affect ST may be of relevance for vulnerability to BP.

β-catenin promoter ChIP-chip reveals potential schizophrenia and bipolar disorder gene network

Therapeutic concentrations of lithium salts inhibit glycogen synthase kinase 3 beta (GSK3β) and phosphoinositide (PI) signaling suggesting that abnormal activation of these pathways could be a factor in the pathophysiology of bipolar disorder (BD). Involvement of these pathways is also supported by recent genome-wide association studies (GWASs). One way investigators have investigated the molecular basis of BD and the therapeutic action of lithium is by microarray expression studies, since both GSK3β- and PI-mediated signal transduction pathways are coupled to transcriptional activation and inhibition. However, expression profiling has some limitations and investigators cannot use the approach to analyze fetal brain tissue, arguably the most relevant biological structure related to the development of genetically based psychiatric disorders. To address these shortcomings, the authors have taken a novel approach using chromatin immunoprecipitation-enriched material annealed to microarrays (ChIP-chip) targeting genes in fetal brain tissue bound by β-catenin, a transcription factor that is directly regulated by GSK3β. The promoters for 640 genes were found to be bound by β-catenin, many of which are known schizophrenia (SZ), autism spectrum disorder (ASD), and BD candidates, including CACNA1B, NRNG, SNAP29, FGFR1, PCDH9, and nine others identified in recently published GWASs and genome-wide searches for copy number variants (CNVs). The findings suggest that seemingly disparate candidate genes for SZ and BD can be incorporated into a common molecular network revolving around GSK3β/β-catenin signaling. In addition, the finding that a putative lithium-responsive pathway may influence a subgroup of SZ and ASD candidate genes could have therapeutic implications.

A kinesin signaling complex mediates the ability of GSK-3beta to affect mood-associated behaviors

Lithium has been the gold standard in the treatment of bipolar disorder (BPD) for 60 y. Like lithium, glycogen synthase kinase 3 (GSK-3) inhibitors display both antimanic-like and antidepressant-like effects in some animal models. However, the molecular mechanisms of both lithium and GSK-3 inhibitors remain unclear. Here we show that the GSK-3 inhibitor AR-A014418 regulated alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA)-induced GluR1 and GluR2 internalization via phosphorylation of kinesin light chain 2 (KLC2), the key molecule of the kinesin cargo delivery system. Specifically, AMPA stimulation triggered serine phosphorylation of KLC2 and, subsequently, the dissociation of the GluR1/KLC2 protein complex. This suggests that GSK-3 phosphorylation of KLC2 led to the dissociation of AMPA-containing vesicles from the kinesin cargo system. The peptide TAT-KLCpCDK, a specific inhibitor for KLC2 phosphorylation by GSK-3beta, reduced the formation of long-term depression. Furthermore, the TAT-KLCpCDK peptide showed antimanic-like effects similar to lithium's on amphetamine-induced hyperactivity, a frequently used animal model of mania. It also induced antidepressant-like effects in the tail suspension and forced swim tests, two commonly used animal models of depression. Taken together, the results demonstrated that KLC2 is a cellular target of GSK-3beta capable of regulating synaptic plasticity, particularly AMPA receptor trafficking, as well as mood-associated behaviors in animal models. The kinesin cargo system may provide valuable novel targets for the development of new therapeutics for mood disorders.

Identification of interaction between serotonin transporter and glycogen synthase kinase-3β gene polymorphisms: role in susceptibility to bipolar disorder

Background: Genetic correlates of diseases of complex inheritance may include variations in several genes lying within a network of linked biological processes. Synaptic mechanisms, such as serotonin neurotransmission and second (third) messengers (e.g., glycogen synthase kinase [GSK]), have been implicated in susceptibility to mood disorders, the actions of therapeutic drugs and manipulation of circadian rhythms. A better understanding of such gene networks may be useful to understand the biology and treatment of mood disorders. Methods: We studied the association between serotonergic and GSK-mediated signaling networks with bipolar affective disorder (BPAD). We analyzed two single nucleotide polymorphisms (SNPs) in the HTR2A gene, a promoter SNP in SLC6A4 and a promoter SNP in the GSK3B gene in BPAD individuals and matched controls. A multifactor dimensionality reduction tool was employed to study gene–gene interactions and analyze multilocus genotype combination associations with high- or low-risk of BPAD. Results: Multifactor dimensionality reduction detected the best interacting model involving 5-HTTLPR (SLC6A4) and rs334558 (GSK3B). Conclusion: Our results suggest interplay between the serotonergic pathway and the second-messenger system involving GSK, which are important drug targets.