Alessandra Minelli

New Copy Number Variations in Schizophrenia

Genome-wide screenings for copy number variations (CNVs) in patients with schizophrenia have demonstrated the presence of several CNVs that increase the risk of developing the disease and a growing number of large rare CNVs; the contribution of these rare CNVs to schizophrenia remains unknown. Using Affymetrix 6.0 arrays, we undertook a systematic search for CNVs in 172 patients with schizophrenia and 160 healthy controls, all of Italian origin, with the aim of confirming previously identified loci and identifying novel schizophrenia susceptibility genes. We found five patients with a CNV occurring in one of the regions most convincingly implicated as risk factors for schizophrenia: NRXN1 and the 16p13.1 regions were found to be deleted in single patients and 15q11.2 in 2 patients, whereas the 15q13.3 region was duplicated in one patient. Furthermore, we found three distinct patients with CNVs in 2q12.2, 3q29 and 17p12 loci, respectively. These loci were previously reported to be deleted or duplicated in patients with schizophrenia but were never formally associated with the disease. We found 5 large CNVs (>900 kb) in 4q32, 5q14.3, 8q23.3, 11q25 and 17q12 in five different patients that could include some new candidate schizophrenia susceptibility genes. In conclusion, the identification of previously reported CNVs and of new, rare, large CNVs further supports a model of schizophrenia that includes the effect of multiple, rare, highly penetrant variants.

Vascular Endothelial Growth Factor (VEGF) serum concentration during electroconvulsive therapy (ECT) in treatment resistant depressed patients.

Vascular endothelial growth factor (VEGF) is an angiogenic cytokine, which induces vasopermeability and facilitates neurogenesis and synaptic plasticity in the adult brain. Expression studies in animal models have reported that brain VEGF is regulated by electroconvulsive seizures (ECS), which are used in an experimental paradigm similar to clinical electroconvulsive therapy (ECT) a treatment for drug resistant depressed (TRD) patients. The aim of this study was to investigate putative modulations of ECT on VEGF serum levels in TRD patients. Nineteen patients were enrolled in the study; illness severity and VEGF serum contents were assessed before the treatment (T0), the day after the end of ECT (T1) and one month later the end of ECT (T2). ECT treatment improved depression symptomatology as measured by MADRS scores (p<0.0001). No changes occurred in serum VEGF between T0 and T1, whereas a significant increase was observed between T0 and T2 (p=0.042). Moreover a significant correlation was observed between the VEGF increase at T2 and the reduction in MADRS scores (p=0.049). This study is the first to evaluate putative modulations of serum VEGF induced by ECT in TRD patients.

Serotonin transporter gene polymorphisms and treatment-resistant depression.

Major Depression Disorder (MDD) is a serious mental illness that is one of the most disabling diseases worldwide. In addition, approximately 15% of depression patients are defined treatment-resistant (TRD). Preclinical and genetic studies show that serotonin modulation dysfunction exists in patients with TRD. Some polymorphisms in the promoter region of the serotonin transporter gene (SLC6A4) are likely to be involved in the pathogenesis/treatment of MDD; however, no data are available concerning TRD. Therefore, in order to investigate the possible influence of SLC6A4 polymorphisms on the risk of TRD, we genotyped 310 DSM-IV MDD treatment-resistant patients and 284 healthy volunteers. We analysed the most studied polymorphism 5-HTTLPR (L/S) and a single nucleotide substitution, rs25531 (A/G), in relation to different functional haplotype combinations. However the correct mapping of rs25531 is still debated whether it is within or outside the insertion. Our sequencing analysis showed that rs25531 is immediately outside of the 5-HTTLPR segment. Differences in 5-HTTLPR allele (p=0.04) and in L allele carriers (p<0.05) were observed between the two groups. Concerning the estimated haplotype analyses, L(A)L(A) homozygote haplotype was more represented among the control subjects (p=0.01, OR=0.64 95%CI: 0.45-0.91). In conclusion, this study reports a protective effect of the L(A)L(A) haplotype on TRD, supporting the hypothesis that lower serotonin transporter transcription alleles are correlated to a common resistant depression mechanism.

Role of allelic variants of FK506-binding protein 51 (FKBP5) gene in the development of anxiety disorders.

Anxiety disorders exhibit remarkably high rates of comorbidity with major depressive disorder (MDD). Mood and anxiety disorders are considered stress‐related diseases. Genetic variations in the co‐chaperone FK506‐binding protein 51, FKBP5, which modulates the function of glucocorticoid receptors, have been associated with an increased risk for the development of posttraumatic stress disorder, but data regarding its role in MDD are controversial. The aims of this study were to clarify the role of the FKBP5 gene in depression and anxiety disorders through a case–control study and an association study with personality traits using the Temperament and Character Inventory (TCI) in healthy subjects.

Altered Gene Expression in Schizophrenia: Findings from Transcriptional Signatures in Fibroblasts and Blood

Background Whole-genome expression studies in the peripheral tissues of patients affected by schizophrenia (SCZ) can provide new insight into the molecular basis of the disorder and innovative biomarkers that may be of great utility in clinical practice. Recent evidence suggests that skin fibroblasts could represent a non-neural peripheral model useful for investigating molecular alterations in psychiatric disorders. Methods A microarray expression study was conducted comparing skin fibroblast transcriptomic profiles from 20 SCZ patients and 20 controls. All genes strongly differentially expressed were validated by real-time quantitative PCR (RT-qPCR) in fibroblasts and analyzed in a sample of peripheral blood cell (PBC) RNA from patients (n = 25) and controls (n = 22). To evaluate the specificity for SCZ, alterations in gene expression were tested in additional samples of fibroblasts and PBCs RNA from Major Depressive Disorder (MDD) (n = 16; n = 21, respectively) and Bipolar Disorder (BD) patients (n = 15; n = 20, respectively). Results Six genes (JUN, HIST2H2BE, FOSB, FOS, EGR1, TCF4) were significantly upregulated in SCZ compared to control fibroblasts. In blood, an increase in expression levels was confirmed only for EGR1, whereas JUN was downregulated; no significant differences were observed for the other genes. EGR1 upregulation was specific for SCZ compared to MDD and BD. Conclusions Our study reports the upregulation of JUN, HIST2H2BE, FOSB, FOS, EGR1 and TCF4 in the fibroblasts of SCZ patients. A significant alteration in EGR1 expression is also present in SCZ PBCs compared to controls and to MDD and BD patients, suggesting that this gene could be a specific biomarker helpful in the differential diagnosis of major psychoses.

Association between baseline serum vascular endothelial growth factor levels and response to electroconvulsive therapy.

Several studies have shown that vascular endothelial growth factor (VEGF) is implicated in different neuronal processes involved in major depressive disorder (MDD) and in the mechanisms of action of antidepressants.

Schizophrenia susceptibility and NMDA-receptor mediated signalling: an association study involving 32 tagSNPs of DAO , DAOA , PPP3CC , and DTNBP1 genes

BackgroundRecent studies supported associations between four NMDA-receptor-mediated signalling genes (D-amino acid oxidase, DAO; D-amino acid oxidase activator, DAOA; protein phosphatase 3 catalytic subunit gamma isoform, PPP3CC; dystrobrevin-binding protein 1, DTNBP1) and schizophrenia susceptibility, even though with contrasting results.MethodsIn an attempt to replicate these findings for the first time in an Italian population, a panel of 32 tagSNPs was analysed in a representative case-control sample involving 879 subjects.ResultsAn association in the allele frequency was observed for the estimated PPP3CC CAG triplotype in the SNP window rs4872499 T/C-rs11780915 A/G-rs13271367 G/A (pcorrect = 0.001). Similarly, the clustered genotype frequencies of the estimated/phased CAG triplotype differed between cases and controls (p = 0.004), with the carriers having a higher frequency in the control population (p = 0.002, odd ratio OR = 0.59, 95% confident interval CI: 0.43-0.82).Following the phenotypic dissection strategy, the analysis of single SNPs evidenced a protective effect in males of rs11780915 and rs13271367 in PPP3CC gene (pcorrect = 0.02, pcorrect = 0.04 respectively). Moreover the estimated/phased GT diplotype (rs2070586A/G-rs3741775G/T) carriers of the DAO gene were more highly represented in female controls (p = 0.017, OR = 0.58, 95% CI: 0.37-0.90), as were the estimated/phased CAG triplotype carriers of the PPP3CC gene in females (p = 0.01, OR = 0.53, 95% CI: 0.32-0.87). In addition, we performed an interaction analysis, and a 66% (p = 0.003, OR = 0.34, 95% CI: 0.17-0.70) lower risk of developing schizophrenia for female (CAG + GT) carriers versus non-CAG or -GT carriers was observed. For DTNBP1, we found a protective effect in males for the rs6459409 (pcorrect = 0.02) and the estimated/phased CT diplotype (rs6459409-rs9476886) carriers (p = 3x10-4, OR = 0.46, 95% CI: 0.30-0.70).In relation to diagnostic subtypes, the estimated/phased DAO GT diplotype and PPP3CC CAG triplotype female carriers were found to show relative risk ratio (RRR) values of 0.52 and 0.54 lower risk for a paranoid phenotype respectively.ConclusionsAlthough the results are preliminary and needed replication in a larger sample, this study suggests that NMDA receptor-mediated signalling genes (DAO, PPP3CC, DTNBP1) might be involved in schizophrenia pathogenic mechanisms related to gender.

Effects of intravenous antidepressant drugs on the excitability of human motor cortex: a study with paired magnetic stimulation on depressed patients.

BACKGROUND The effect of various drugs was investigated by using transcranial magnetic stimulation (TMS) both in healthy subjects and patients, and the results indicated an influence of antidepressant drugs (ADs) on motor excitability. OBJECTIVE The aim of our study was to analyze the effects of two ADs, the tricyclic (TCA) clomipramine and the serotoninergic antidepressant (SSRI) citalopram on the motor cortex excitability in major depressed patients with TMS. METHODS Thirty affected subjects were placed into three groups: two received an intravenous dose of 25 mg clomipramine or 40 mg citalopram, and one received an injection of a placebo. Motor cortex excitability was studied by single and paired TMS before and after 3.5, 8, and 24 hours from administration of the drugs and placebo. Motor cortical excitability was measured using different TMS parameters: resting motor threshold (RMT), motor-evoked potential (MEP) amplitude, intracortical inhibition (ICI), and intracortical facilitation (ICF). RESULTS The results indicated a temporary but significant increase of RMT and ICI and a decrease of ICF after the administration of both drugs, with a longer inhibition for the clomipramine rather than the citalopram. MEP amplitude was not significantly affected by the antidepressant injections. CONCLUSIONS Our findings highlight that a single intravenous dose of clomipramine or citalopram exerts a significant but transitory suppression of motor cortex excitability in depressed patients. TMS represents a useful research tool in assessing the effects of motor cortical excitability of drugs used in the treatment of mental disorders.

An association of GRIK3 Ser310Ala functional polymorphism with personality traits.

Personality traits are under genetic control, and have been associated with genes implicated in dopaminergic, serotoninergic and noradrenergic neurotransmission systems, often with conflicting results. There have been few studies assessing the involvement of the glutamatergic pathway instead upon personality traits. In the gene family of glutamate receptors, there is a T/G polymorphism at codon 928 in the ionotropic glutamate receptor kainite 3 gene (GRIK3) that causes a serine to alanine change at position 310 in the extracellular N terminus of the protein. This polymorphism has been recently associated with susceptibility to some major psychoses such as major depression (MD). In order to test whether the functional Ser310Ala polymorphism is involved in the development of specific personality traits, and thus to MD, we conducted the first association study on 195 selected healthy Italian individuals. The personality traits were measured by the self-rating Temperament and Character Inventory (TCI) scale. The results indicated that the Ala allele in homozygosity is associated with higher scores in harm avoidance and respective subscales: anticipatory worry HA1 and shyness HA3, as well as lower scores in exploratory excitability NS1, responsibility SD1, resourcefulness SD3, helpfulness C3 and compassion C4 subscales, in addition to lower self-directedness and cooperativeness scores. This pattern of TCI scores is akin to that observed in depressed patients. Because of the small size of the sample, this work represents a pilot study, and reports the first pieces of evidence for a specific involvement of the GRIK3 gene in these traits, suggesting a role of the glutamatergic system in the genetic background of human personality traits.

Personality Traits in an Italian Sample: Relationship with Anxiety and Depression

Personality traits provide a description of individual emotional and cognitive processes that modulate thoughts, feelings and behaviour. Few studies have investigated the relationship of personality traits with depression and anxiety in the general Italian population. The aim of the present study was to replicate previous evidences about the association of personality traits with anxiety and depression in a general Italian population sample. We recruited 418 volunteers through different sources; such as university, newspaper advertisement, hospital, and elderly association. 327 subjects accepted to participate to the study and were screened with the Mini-International Neuropsychiatric Interview (M.I.N.I.) in order to assess DSM-IV Axis I disorders and with the Temperament and Character Inventory (TCI) in order to measure personality traits. Based on the assessment made by the MINI, the whole sample consisted of 266 (81%) subjects without and 61 subjects (19%) with life-time DSM-IV Axis I disorders. Volunteers with life-time anxiety and depressive disorders showed high scores in Harm Avoidance as well as low scores in Self-Directedness and in the Novelty Seeking subscale “Exploratory Excitability”. Our results support previous evidences showing that personality traits, in particular Harm Avoidance and Self-Directedness, could represent markers of vulnerability for depression and anxiety disorders.