Schizophrenia risk conferred by rare protein-truncating variants is conserved across diverse human populations

Schizophrenia (SCZ) is a chronic mental illness and among the most debilitating conditions encountered in medical practice. A recent landmark SCZ study of the protein-coding regions of the genome identified a causal role for ten genes and a concentration of rare variant signals in evolutionarily constrained genes1. This recent study-and most other large-scale human genetics studies-was mainly composed of individuals of European (EUR) ancestry, and the generalizability of the findings in non-EUR populations remains unclear. To address this gap, we designed a custom sequencing panel of 161 genes selected based on the current knowledge of SCZ genetics and sequenced a new cohort of 11,580 SCZ cases and 10,555 controls of diverse ancestries. Replicating earlier work, we found that cases carried a significantly higher burden of rare protein-truncating variants (PTVs) among evolutionarily constrained genes (odds ratio = 1.48; P = 5.4 × 10-6). In meta-analyses with existing datasets totaling up to 35,828 cases and 107,877 controls, this excess burden was largely consistent across five ancestral populations. Two genes (SRRM2 and AKAP11) were newly implicated as SCZ risk genes, and one gene (PCLO) was identified as shared by individuals with SCZ and those with autism. Overall, our results lend robust support to the rare allelic spectrum of the genetic architecture of SCZ being conserved across diverse human populations.

A machine learning approach on whole blood immunomarkers to identify an inflammation-associated psychosis onset subgroup

Psychosis onset is a transdiagnostic event that leads to a range of psychiatric disorders, which are currently diagnosed through clinical observation. The integration of multimodal biological data could reveal different subtypes of psychosis onset to target for the personalization of care. In this study, we tested the existence of subgroups of patients affected by first-episode psychosis (FEP) with a possible immunopathogenic basis. To do this, we designed a data-driven unsupervised machine learning model to cluster a sample of 127 FEP patients and 117 healthy controls (HC), based on the peripheral blood expression levels of 12 psychosis-related immune gene transcripts. To validate the model, we applied a resampling strategy based on the half-splitting of the total sample with random allocation of the cases. Further, we performed a post-hoc univariate analysis to verify the clinical, cognitive, and structural brain correlates of the subgroups identified. The model identified and validated two distinct clusters: 1) a FEP cluster characterized by the high expression of inflammatory and immune-activating genes (IL1B, CCR7, IL12A and CXCR3); 2) a cluster consisting of an equal number of FEP and HC subjects, which did not show a relative over or under expression of any immune marker (balanced subgroup). None of the subgroups was related to specific symptoms dimensions or longitudinal diagnosis of affective vs non-affective psychosis. FEP patients included in the balanced immune subgroup showed a thinning of the left supramarginal and superiorfrontal cortex (FDR-adjusted p-values < 0.05). Our results demonstrated the existence of a FEP patients' subgroup identified by a multivariate pattern of immunomarkers involved in inflammatory activation. This evidence may pave the way to sample stratification in clinical studies aiming to develop diagnostic tools and therapies targeting specific immunopathogenic pathways of psychosis.

Clinical validation of a combinatorial PharmAcogeNomic approach in major Depressive disorder: an Observational prospective RAndomized, participant and rater-blinded, controlled trial (PANDORA trial)

Background

Major depressive disorder (MDD) is a common, chronic, debilitating mood disorder that causes serious functional impairment and significantly decreased quality of life. Pharmacotherapy represents the first-line treatment option; however, only approximately one third of patients respond to the first treatment because of the ineffectiveness or side effects of antidepressants. Precision medicine in psychiatry might offer clinicians the possibility to tailor treatment according to the best possible evidence of efficacy and tolerability for each subject. In this context, our study aims to carry out a clinical validation of a combinatorial pharmacogenomics (PGx) test in an Italian MDD patient cohort with advocacy license independence.

Methods

Our study is a prospective participant- and rater-blinded, randomized, controlled clinical observational trial enrolling 300 MDD patients who are referred to psychiatric services to receive a new antidepressant due to the failure of their current treatment and/or the onset of adverse effects. Eligible participants are randomized to the TGTG group (Treated with Genetic Test Guide) or TAU group (Treated as Usual). For all subjects, DNA is collected with a buccal brush. The primary outcome is the reduction in depressive symptomatology. The secondary outcomes involve a range of scales that assess MDD symptoms and social functioning outcomes. The assessment is performed at four timepoints: baseline and 4, 8, and 12 weeks.

Discussion

This project represents the first randomized controlled clinical trial to investigate whether a non-commercial PGx test improves outcomes in an MDD naturalistic cohort. Moreover, the identification of new genetic variants associated with non-response or side effects will improve the efficacy of the test, leading to further cost-saving.

Trial registration number

ClinicalTrials.gov NCT04615234. Registered on November 4, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05775-8.

Classification of Psychoses Based on Immunological Features: A Machine Learning Study in a Large Cohort of First-Episode and Chronic Patients

For several years, the role of immune system in the pathophysiology of psychosis has been well-recognized, showing differences from the onset to chronic phases. Our study aims to implement a biomarker-based classification model suitable for the clinical management of psychotic patients. A machine learning algorithm was used to classify a cohort of 362 subjects, including 160 first-episode psychosis patients (FEP), 70 patients affected by chronic psychiatric disorders (schizophrenia, bipolar disorder, and major depressive disorder) with psychosis (CRO) and 132 health controls (HC), based on mRNA transcript levels of 56 immune genes. Models distinguished between FEP, CRO, and HC and between the subgroup of drug-free FEP and HC with a mean accuracy of 80.8% and 90.4%, respectively. Interestingly, by using the feature importance method, we identified some immune gene transcripts that contribute most to the classification accuracy, possibly giving new insights on the immunopathogenesis of psychosis. Therefore, our results suggest that our classification model has a high translational potential, which may pave the way for a personalized management of psychosis.

Alterations observed in the interferon α and β signaling pathway in MDD patients are marginally influenced by cis-acting alleles

Major depressive disorder (MDD) is a common psychiatric disorder with a multifactorial aetiology determined by the interaction between genetic and environmental risk factors. Pieces of evidence indicate that inflammation and immune activation may contribute to the onset of MDD playing a role in the pathogenetic mechanism. To date, it is not known to which extent the association between MDD and inflammation is shaped by the genetic background or by the presence of environmental factors. To clarify this issue, we analyzed genotype and blood RNA profiles of 463 MDD cases and 459 controls (NIMH-Study 88/Site621) estimating the Genetic and Environmental Regulated eXpression component of gene expression (GReX and EReX respectively). Both components were tested for association with MDD. Many genes belonging to the α/β interferon signaling pathway showed an association between MDD and EReX, only two between MDD and GReX. Also other MDD differentially expressed genes were more influenced by the EReX than by GReX. These results suggest that impact of the genetic background on MDD blood gene expression alterations is much lower than the contribution of environmental factors and almost absent for the genes of the interferon pathway.

Inflammation-related microRNAs are involved in stressful life events exposure and in trauma-focused psychotherapy in treatment-resistant depressed patients

BACKGROUND

About 30% of major depressive disorder (MDD) patients are classified as resistant to treatment (treatment-resistant depression, TRD). Among the factors associated with unfavourable treatment outcomes, stressful life events play a relevant role, and trauma-focused psychotherapy has been successfully proposed for the treatment of patients with a history of such events. Stressful experiences are related to enhanced inflammation and, recently, microRNAs (miRNAs) have emerged as potential mediators of the association between these experiences and psychiatric disorders. To date, no study has explored the effects of stressful life events on miRNAs in MDD patients.

OBJECTIVE

The objective of the present study was to assess possible miRNA blood expression alterations in TRD patients induced by the exposure to stressful life events and to investigate the effects of trauma-focused psychotherapy on the expression profiles of the same miRNAs, as well as their possible predictivity in relation to therapy outcome.

METHOD

The basal levels (T0) of seven candidate miRNAs (miR-15a/miR-29a/miR-125b/miR-126/miR-146a/miR-195/let-7f) were measured in the whole blood of 41 TRD patients. A subgroup of patients (n = 21) underwent trauma-focused psychotherapy; for all of them, miRNA levels were also longitudinally assessed (T4: after 4 weeks of treatment; T8: end of treatment; T12: follow-up visit), contextually to clinical evaluations.

RESULTS

miR-146a levels negatively correlated with recent stressful life event scores (p = .001), whereas the levels of miR-15a, miR-29a, miR-126, miR-195, and let-7f changed during the psychotherapy (best p = 1.98*10^-9). miR-29a was also identified as a response predictor, with lower baseline levels predicting non-response (p = .019) or worse improvement in mood symptoms (p = .032).

CONCLUSIONS

The study results could contribute to clarify the underlying molecular mechanisms and to identify novel biomarkers of stressful experiences and response to targeted treatments.

Correlations between immune and metabolic serum markers and schizophrenia/bipolar disorder polygenic risk score in first-episode psychosis

AIMS

There is a strong interest in identifying the biological mechanisms involved in the genetic risk for psychotic disorders. In this study, we evaluated the correlation between serum concentrations of specific molecular markers and the genetic component for schizophrenia and bipolar disorder.

METHODS

We analysed the association between the polygenic risk score (PRS) and the serum levels of different inflammatory/metabolic markers in a sample of 81 first-episode psychosis patients (FEP) with a diagnosis of schizophrenia or bipolar disorder and 33 controls.

RESULTS

A positive correlation of schizophrenia and bipolar disorder PRS with the inflammatory marker C-C Motif Chemokine Ligand 4 serum concentration (ρ = 0.42, P = 1.56 × 10^-04 and ρ = 0.40, P = 1.65 × 10^-03 , respectively) and a negative correlation with the serum ghrelin content (ρ = - 0.35, P = 4.27 × 10^-03 and ρ = - 0.45, P = 6.05 × 10^-04 , respectively) were observed.

CONCLUSION

These findings provide new insight into the biological underpinnings of the PRS component, thus supporting a role of the genetic liability on the inflammatory and metabolic alterations that characterize psychosis onset.

Childhood trauma and glucose metabolism in patients with first-episode psychosis

Although the associations between first-episode psychosis (FEP) and metabolic abnormalities on one side, and childhood trauma (CT) and risk of developing psychosis on the other are both well established, evidence on the relationship between CT and metabolic dysregulation in terms of abnormal glucose metabolism is very limited. We tested whether, already at illness onset, FEP patients with a history of CT show dysregulation of a broad range of glucose metabolism markers. In particular, in 148 FEP patients we evaluated serum concentrations of c-peptide, insulin, plasminogen-activator-inhibitor-1 (PAI-1), resistin, visfatin, glucagon, glucagon-like peptide-1 (GLP-1), gastric-inhibitor-peptide (GIP), leptin, and ghrelin. We also assessed CT with the Childhood Experience of Care and Abuse Questionnaire, and stressful life events (SLEs) with a semi-structured interview. Psychopathology, cannabis and tobacco habits, Body Mass Index (BMI) were recorded. Serum concentrations of markers were analyzed from peripheral blood. Ninety-five patients (56 % males, mean age 29.5) reported CT. Multivariate models showed that CT is associated only with the concentrations of c-peptide and insulin after adjusting for age, sex, BMI and SLEs. FEP patients who had experienced CT showed higher c-peptide and insulin serum concentrations. Our study reports that CT might be associated with the metabolic abnormalities in the first stage of psychosis, suggesting that a thorough anamnestic evaluation at psychosis onset that would include the history of CT could be helpful for clinicians in order to implement early programmes of healthy lifestyle education and to guide choice of therapeutic interventions for trauma.

miR-146a Plasma Levels Are Not Altered in Alzheimer's Disease but Correlate With Age and Illness Severity

miR-146a is a microRNA (miRNA) involved in neuroinflammation and aging; alterations in its expression were described in Alzheimer’s disease (AD). However, most of the studies conducted so far on this miRNA included a limited number of participants and produced contradictory results. We compared miR-146a levels in plasma from 33 AD patients vs. 28 age-matched non-affected controls (CTRL) through quantitative real-time polymerase chain reaction (qRT-PCR). No difference between the case and the control group was evidenced, but a correlation was detected between miR-146a levels and subjects’ age (p < 0.001) as well as between miR-146a levels and patients’ Mini-Mental State Examination (MMSE) scores (p = 0.011), in an enlarged group of 51 AD patients and 45 CTRL supporting a role for this miRNA in aging processes and disease progression.

miR-146a and miR-181a are involved in the progression of mild cognitive impairment to Alzheimer's disease

The identification of mechanisms associated with Alzheimer's disease (AD) development in mild cognitive impairment (MCI) would be of great usefulness to clarify AD pathogenesis and to develop preventive and therapeutic strategies. In this study, blood levels of the candidate microRNAs (small noncoding RNAs that play a pivotal role in gene expression) miR-146a, miR-181a, miR-181b, miR-24-3p, miR-186a, miR-101, miR-339, miR-590, and miR-22 have been investigated for association to AD conversion within 2 years in a group of 45 patients with MCI. Baseline miR-146a (p = 0.036) and miR-181a (p = 0.026) showed a significant upregulation in patients with MCI who later converted to AD. These alterations were related to AD hallmarks: a significant negative correlation was found with amyloid beta cerebrospinal fluid concentration for miR-146a (p = 0.006) and miR-181a (p = 0.001). Moreover, higher levels of miR-146a were associated to apolipoprotein E ε4 allele presence, smaller volume of the hippocampus (p = 0.045) and of the CA1 (p = 0.013) and the subiculum (p = 0.027) subfields. Increased levels of miR-146a (p = 0.031) and miR-181a (p = 0.002) were also linked with diffusivity alterations in the cingulum. These data support a role for miR-146a and miR-181a in the mechanisms of AD progression.

Insulin-like growth factor binding protein 2 in bipolar disorder: An expression study in peripheral tissues

OBJECTIVES

Insulin-like growth factor binding protein 2 (IGFBP2) is a member of the family of high-affinity binding proteins (IGFBP1-6) and appears to play a governing role in insulin-like growth factor (IGF) regulation in the central nervous system. This study aimed to investigate the putative involvement of IGFBP2 in mood disorder pathogenesis by measuring its expression levels in patient peripheral tissues.

METHODS

IGFBP2 protein and mRNA levels were measured in the serum of 93 controls, 41 bipolar disorder (BD) and 43 major depressive disorder (MDD) patients and in the skin fibroblasts from 15 controls, 12 BD and 23 MDD patients.

RESULTS

The results indicated reduced expression of IGFBP2 in both tissues of BD patients, whereas no difference was found in MDD patients compared with controls.

CONCLUSIONS

Our findings in peripheral tissues are consistent with previous results in the brain and support a downregulation of IGFBP2 expression that is specific for BD, suggesting a role for this protein in the alterations in neurodevelopment and neuroprotection observed in the disorder. Further studies in independent and larger cohorts are warranted to confirm the involvement of IGFBP2 in BD.

Immune and metabolic alterations in first episode psychosis (FEP) patients

The molecular underpinnings associated to first episode psychosis (FEP) remains to be elucidated, but compelling evidence supported an association of FEP with blood alterations in biomarkers related to immune system, growth factors and metabolism regulators. Many of these studies have not been already confirmed in larger samples or have not considered the FEP diagnostic subgroups. In order to identify biochemical signatures of FEP, the serum levels of the growth factors BDNF and VEGF, the immune regulators IL-1RA, IL-6, IL-10 and IL-17, RANTES/CCL5, MIP-1b/CCL4, IL-8 and the metabolic regulators C-peptide, ghrelin, GIP, GLP-1, glucagon, insulin, leptin, PAI-1, resistin and visfatin were analysed in 260 subjects collected in the GET UP project. The results indicated an increase of MIP-1b/CCL4, VEGF, IL-6 and PAI-1, while IL-17, ghrelin, glucagon and GLP-1 were decreased in the whole sample of FEP patients (p < 0.01 for all markers except for PAI-1 p < 0.05). No differences were evidenced for these markers among the diagnostic groups that constitute the FEP sample, whereas IL-8 is increased only in patients with a diagnosis of affective psychosis. The principal component analysis (PCA) and variable importance analysis (VIA) indicated that MIP-1b/CCL4, ghrelin, glucagon, VEGF and GLP-1 were the variables mostly altered in FEP patients. On the contrary, none of the analysed markers nor a combination of them can discriminate between FEP diagnostic subgroups. These data evidence a profile of immune and metabolic alterations in FEP patients, providing new information on the molecular mechanism associated to the psychosis onset for the development of preventive strategies and innovative treatment targets.

Study of the in vitro modulation exerted by the antidepressant drug escitalopram on the expression of candidate microRNAs and their target genes

Recent studies indicated a role of microRNAs (miRNAs, small non-coding RNAs which regulate the expression of target genes by acting on mRNAs) in several neural processes, in the pathogenetic mechanisms of neuropsychiatric diseases and in the action of psychotropic drugs. A modulation induced by the antidepressant drug escitalopram on the expression levels of 30 miRNAs was highlighted in the blood of patients suffering from major depressive disorder. With the aim to investigate the effects of escitalopram in an in vitro model, we performed an analysis of the effects produced by escitalopram on the profiles of the 6 miRNAs found to be more significantly modulated in the above-mentioned study (miR-130b, miR-26a and -26b, let-7f, miR-770-5p, miR-34c-5p) in human U87 glioblastoma cells. Cells were treated with the drug for 24, 48 and 72h. The obtained results confirmed a significant increase of let-7f, both after 48 (p=0.031) and 72h (p=0.022), and of miR-26a after 48h (p=0.032). On the same experimental model, a transcriptome analysis was conducted after 72h, highlighting a drug-induced modulation of 1184 protein-coding genes, 207 of which represent let-7f targets. Particularly interesting was the downregulation of BCOR, CCND1 and ATR, validated let-7f targets, which play a key role in the mechanisms of neurogenesis, neuroplasticity and protection from oxidative stress in the brain, indicating that escitalopram could exert downstream effects on gene expression through the regulation of specific miRNAs.

Serum Levels of Insulin-Like Growth Factor-1 and Obsessive-Compulsive Disorder: A Case-Control Study

BACKGROUND/AIMS

Recent findings suggest an involvement of insulin-like growth factor-1 (IGF-1) in the pathogenesis of many psychiatric disorders; however, there is a lack of data regarding IGF-1 in patients with obsessive-compulsive disorder (OCD). The aims of the present study were (1) to analyze putative alterations of IGF-1 serum content in patients with OCD compared to patients with major depressive disorder (MDD) and healthy controls, and (2) to analyze putative changes of IGF-1 levels during drug treatment in subjects with OCD compared to patients with MDD.

METHODS

We recruited 40 OCD patients, 37 MDD patients, and 43 healthy controls. All participants were adults. Serum IGF-1 levels were measured by the ELISA method on venous blood samples collected at baseline and after 10 ± 1 weeks of drug treatment.

RESULTS

IGF-1 levels were increased in OCD patients compared to controls (149.9 ± 60.2 vs. 121.2 ± 51.6 ng/ml; p = 0.040). No correlations were observed between baseline IGF-1 levels, clinical features, and response to treatment at follow-up in OCD or MDD patients. No changes in serum IGF-1 were observed after drug treatment.

CONCLUSION

Our results show for the first time that serum IGF-1 levels are altered in patients with OCD. Further research on the role of IGF-1 in OCD is warranted.

Nanomedicine in Psychiatry: New Therapeutic Opportunities from Research on Small RNAs

Preclinical Research Alterations in small non-coding RNAs have been observed in many human disease states including cancer, cardiovascular, developmental, neurological, and psychiatric disorders. These molecules have recently raised the interest of the scientific community for novel therapeutic approaches. Nanotechnologies, including the development of sophisticated nanoparticles, offer new ways for the delivery of small RNA-based therapies. The nanoparticle delivery method appears attractive, but so far most of the work in this area has been conducted in the context of cancer. New therapeutic strategies are needed for psychiatric disorders, where treatment is often ineffective, leading to frequent patient hospitalizations and a growing economic burden. In this article, we discuss the role of small RNAs in psychiatric diseases and how this new knowledge, combined with innovations in nanotechnologies, could lead to the development of novel therapeutic approaches. Drug Dev Res 77 : 453-457, 2016. © 2016 Wiley Periodicals, Inc.

Effects of Intranasal Oxytocin on Long-Term Memory in Healthy Humans: A Systematic Review

Preclinical Research The neuropeptide oxytocin (Oxt) is implicated in complex emotional and social behaviors and appears to play an important role in learning and memory. Animal studies have shown that the effects of exogenous Oxt on memory vary according to the timing of administration, context, gender, and dose and may improve the memory of social, but not nonsocial stimuli. Oxt is intimately involved in a broad array of neuropsychiatric functions and may therefore be a pharmacological target for several psychiatric disorders. This review summarizes the potential effects of Oxt on long-term memory processes in healthy humans based on a PubMed search over the period 1980-2016. The effects of intranasal Oxt on human memory are controversial and the studies included in this review have applied a variety of learning paradigms, in turn producing variable outcomes. Specifically, data on the long-term memory of nonemotional stimuli found no effect or even worsening in memory, while studies using emotional stimuli showed an improvement of long-term memory performance. In conclusion, this review identified a link between long-term memory performance and exogenous intranasal Oxt in humans, although these results still warrant further confirmation in large, multicenter randomized controlled trials. Drug Dev Res 77 : 479-488, 2016. © 2016 Wiley Periodicals, Inc.

Peripheral whole blood microRNA alterations in major depression and bipolar disorder

Major depression (MD) and bipolar disorder (BD) are severe and potentially life-threating mood disorders whose etiology is to date not completely understood. MicroRNAs (miRNAs) are small non-coding RNAs that regulate protein synthesis post-transcriptionally by base-pairing to target gene mRNAs. Growing evidence indicated that miRNAs might play a key role in the pathogenesis of neuropsychiatric disorders and in the action of psychotropic drugs. On these bases, in this study we evaluated the expression levels of 1733 mature miRNAs annotated in miRBase v.17, through a microarray technique, in the blood of 20 MD and 20 BD patients and 20 healthy controls, in order to identify putative miRNA signatures associated with mood disorders. We found that 5 miRNAs (hsa-let-7a-5p, hsa-let-7d-5p, hsa-let-7f-5p, hsa-miR-24-3p and hsa-miR-425-3p) were specifically altered in MD patients and 5 (hsa-miR-140-3p, hsa-miR-30d-5p, hsa-miR-330-5p, hsa-miR-378a-5p and hsa-miR-21-3p) in BD patients, whereas 2 miRNAs (hsa-miR-330-3p and hsa-miR-345-5p) were dysregulated in both the diseases. The bioinformatic prediction of the genes targeted by the altered miRNAs revealed the possible involvement of neural pathways relevant for psychiatric disorders. In conclusion, the observed results indicate a dysregulation of miRNA blood expression in mood disorders and could indicate new avenues for a better understanding of their pathogenetic mechanisms. The identified alterations may represent potential peripheral biomarkers to be complemented with other clinical and biological features for the improvement of diagnostic accuracy.

Absolute Measurements of Macrophage Migration Inhibitory Factor and Interleukin-1-β mRNA Levels Accurately Predict Treatment Response in Depressed Patients

BACKGROUND

Increased levels of inflammation have been associated with a poorer response to antidepressants in several clinical samples, but these findings have had been limited by low reproducibility of biomarker assays across laboratories, difficulty in predicting response probability on an individual basis, and unclear molecular mechanisms.

METHODS

Here we measured absolute mRNA values (a reliable quantitation of number of molecules) of Macrophage Migration Inhibitory Factor and interleukin-1β in a previously published sample from a randomized controlled trial comparing escitalopram vs nortriptyline (GENDEP) as well as in an independent, naturalistic replication sample. We then used linear discriminant analysis to calculate mRNA values cutoffs that best discriminated between responders and nonresponders after 12 weeks of antidepressants. As Macrophage Migration Inhibitory Factor and interleukin-1β might be involved in different pathways, we constructed a protein-protein interaction network by the Search Tool for the Retrieval of Interacting Genes/Proteins.

RESULTS

We identified cutoff values for the absolute mRNA measures that accurately predicted response probability on an individual basis, with positive predictive values and specificity for nonresponders of 100% in both samples (negative predictive value=82% to 85%, sensitivity=52% to 61%). Using network analysis, we identified different clusters of targets for these 2 cytokines, with Macrophage Migration Inhibitory Factor interacting predominantly with pathways involved in neurogenesis, neuroplasticity, and cell proliferation, and interleukin-1β interacting predominantly with pathways involved in the inflammasome complex, oxidative stress, and neurodegeneration.

CONCLUSION

We believe that these data provide a clinically suitable approach to the personalization of antidepressant therapy: patients who have absolute mRNA values above the suggested cutoffs could be directed toward earlier access to more assertive antidepressant strategies, including the addition of other antidepressants or antiinflammatory drugs.

Glucose metabolism alterations in patients with bipolar disorder

Patients with bipolar disorder (BD) are more frequently affected by metabolic syndrome (MetS) than the general population, but the neurobiological correlates underlying such association are still not clarified and few studies in BD have evaluated the role of regulators of lipid and glucose metabolism. The present study was aimed to investigate putative alterations in markers linked to metabolic dysfunctions as C-peptide, Ghrelin, GIP, GLP-1, Glucagon, Insulin, Leptin, PAI-1 (total), Resistin and Visfatin in a sample of BD patients compared to controls. Furthermore, associations between changes of metabolic markers and relevant clinical features, such as severity of symptomatology, number and type of past mood episodes, drug treatments and presence/absence of metabolic alterations (MetS, diabetes and cardiovascular disease) were analyzed. A total of 57 patients with BD and 49 healthy controls were recruited. The main results showed lower serum levels of Glucagon, GLP-1, Ghrelin, and higher levels of GIP in BD patients as compared to controls (p = 0.018 for Ghrelin; p < 0.0001 for Glucagon; p < 0.0001 for GLP-1; p < 0.0001 for GIP). Further, Glucagon and GLP-1 levels were significantly associated with the number of past mood episodes. These findings support the hypothesis that alterations in Glucagon, GLP-1, GIP and Ghrelin might be involved in BD pathogenesis and might represent useful biomarkers for the development of preventive and personalized therapies in this disorder.

Alzheimer's disease cerebrospinal fluid biomarker in cognitively normal subjects

In a large multicentre sample of cognitively normal subjects, as a function of age, gender and APOE genotype, we studied the frequency of abnormal cerebrospinal fluid levels of Alzheimer's disease biomarkers including: total tau, phosphorylated tau and amyloid-β1-42. Fifteen cohorts from 12 different centres with either enzyme-linked immunosorbent assays or Luminex® measurements were selected for this study. Each centre sent nine new cerebrospinal fluid aliquots that were used to measure total tau, phosphorylated tau and amyloid-β1-42 in the Gothenburg laboratory. Seven centres showed a high correlation with the new Gothenburg measurements; therefore, 10 cohorts from these centres are included in the analyses here (1233 healthy control subjects, 40-84 years old). Amyloid-β amyloid status (negative or positive) and neurodegeneration status (negative or positive) was established based on the pathological cerebrospinal fluid Alzheimer's disease cut-off values for cerebrospinal fluid amyloid-β1-42 and total tau, respectively. While gender did not affect these biomarker values, APOE genotype modified the age-associated changes in cerebrospinal fluid biomarkers such that APOE ε4 carriers showed stronger age-related changes in cerebrospinal fluid phosphorylated tau, total tau and amyloid-β1-42 values and APOE ε2 carriers showed the opposite effect. At 40 years of age, 76% of the subjects were classified as amyloid negative, neurodegeneration negative and their frequency decreased to 32% at 85 years. The amyloid-positive neurodegeneration-negative group remained stable. The amyloid-negative neurodegeneration-positive group frequency increased slowly from 1% at 44 years to 16% at 85 years, but its frequency was not affected by APOE genotype. The amyloid-positive neurodegeneration-positive frequency increased from 1% at 53 years to 28% at 85 years. Abnormally low cerebrospinal fluid amyloid-β1-42 levels were already frequent in midlife and APOE genotype strongly affects the levels of cerebrospinal fluid amyloid-β1-42, phosphorylated tau and total tau across the lifespan without influencing the frequency of subjects with suspected non-amyloid pathology.

Inflammation and neuronal plasticity: a link between childhood trauma and depression pathogenesis

During the past two decades, there has been increasing interest in understanding and characterizing the role of inflammation in major depressive disorder (MDD). Indeed, several are the evidences linking alterations in the inflammatory system to Major Depression, including the presence of elevated levels of pro-inflammatory cytokines, together with other mediators of inflammation. However, it is still not clear whether inflammation represents a cause or whether other factors related to depression result in these immunological effects. Regardless, exposure to early life stressful events, which represent a vulnerability factor for the development of psychiatric disorders, act through the modulation of inflammatory responses, but also of neuroplastic mechanisms over the entire life span. Indeed, early life stressful events can cause, possibly through epigenetic changes that persist over time, up to adulthood. Such alterations may concur to increase the vulnerability to develop psychopathologies. In this review we will discuss the role of inflammation and neuronal plasticity as relevant processes underlying depression development. Moreover, we will discuss the role of epigenetics in inducing alterations in inflammation-immune systems as well as dysfunction in neuronal plasticity, thus contributing to the long-lasting negative effects of stressful life events early in life and the consequent enhanced risk for depression. Finally we will provide an overview on the potential role of inflammatory system to aid diagnosis, predict treatment response, enhance treatment matching, and prevent the onset or relapse of Major Depression.

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

OBJECTIVE

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. The aim of this study was to investigate whether VEGF serum levels before treatment might be associated with the antidepressant response.

METHOD

Two groups of patients were enrolled. One was composed of 50 MDD patients receiving an antidepressant drug treatment. Illness severity was measured before the treatment (T0) and after 12 weeks (T1). The second group was composed of 67 treatment-resistant depressed (TRD) patients undergoing electroconvulsive therapy (ECT). Illness severity was assessed before the treatment (T0) and 1 month after the end of ECT (T1). Blood samples for VEGF measurements were collected for both groups at the baseline (T0).

RESULTS

A significant correlation was observed between baseline VEGF serum levels and the percentage reduction in depressive symptomatology after ECT (P = 0.003). In particular, VEGF levels at baseline were significantly lower in patients showing no response to ECT at follow-up (P = 0.008). No correlation between T0 VEGF concentrations and drug treatment outcome was found.

CONCLUSION

Our results suggest that VEGF plays a role in the mechanism of response to ECT.

Micro spies from the brain to the periphery: new clues from studies on microRNAs in neuropsychiatric disorders

microRNAs (miRNAs) are small non-coding RNAs (20-22 nucleotides) playing a major role in post-transcriptional regulation of gene expression. miRNAs are predicted to regulate more than 50% of all the protein-coding genes. Increasing evidence indicates that they may play key roles in the biological pathways that regulate neurogenesis and synaptic plasticity, as well as in neurotransmitter homeostasis in the adult brain. In this article we review recent studies suggesting that miRNAs may be involved in the pathophysiology of neuropsychiatric disorders and in the action of psychotropic drugs, in particular by analyzing the contribution of genomic studies in patients' peripheral tissues. Alterations in miRNA expression have been observed in schizophrenia, bipolar disorder, major depression, Parkinson's disease, Alzheimer's disease and other neuropsychiatric conditions. In particular, intriguing findings concern the identification of disease-associated miRNA signatures in peripheral tissues, or modifications in miRNA profiles induced by drug treatments. Furthermore, genetic variations in miRNA sequences and miRNA-related genes have been described in neuropsychiatric diseases. Overall, though still at a preliminary stage, several lines of evidence indicate an involvement of miRNAs in both the pathophysiology and pharmacotherapy of neuropsychiatric disorders. In this regard, the data obtained in peripheral tissues may provide further insights into the etiopathogenesis of several brain diseases and contribute to identify new biomarkers for diagnostic assessment improvement and treatment personalization.

Serum brain-derived neurotrophic factor (BDNF) levels in attention deficit-hyperactivity disorder (ADHD)

It has been proposed that the neurotrophin brain-derived neurotrophic factor (BDNF) may be involved in attention deficit-hyperactivity disorder (ADHD) etiopathogenesis. Alterations in BDNF serum levels have been observed in childhood/adulthood neurodevelopmental pathologies, but no evidence is available for BDNF serum concentrations in ADHD. The study includes 45 drug-naïve ADHD children and 45 age-sex matched healthy subjects. Concentration of serum BDNF was determined by the ELISA method. BDNF serum levels in patients with ADHD were not different from those of controls (mean ± SD; ADHD: 39.33 ± 10.41 ng/ml; controls: 38.82 ± 8.29 ng/ml, t = -0.26, p = 0.80). Our findings indicate no alteration of serum BDNF levels in untreated patients with ADHD. A further stratification for cognitive, neuropsychological and psychopathological assessment in a larger sample could be useful to clarify the role of BDNF in the endophenotype characterization of ADHD.

BDNF serum levels, but not BDNF Val66Met genotype, are correlated with personality traits in healthy subjects

Consisting evidence in animal models has suggested that alterations in brain-derived neurotrophic factor (BDNF) brain expression and release are involved in the pathogenesis of mental illnesses, such as, mood, anxiety, and eating disorders. This hypothesis is supported by data emerging from biochemical studies on serum BDNF levels and genetic studies on the functional polymorphism Val66Met in the BDNF gene in patients and control subjects. Anxiety-related personality traits are associated with several mental disorders. However, they are also measurable in non-affected subjects and, so, may represent a useful "endophenotype" to study the biological correlation of the vulnerability factors in the general population. In this study, we analyzed putative correlations in subjects unaffected by mental disorders between personality traits, serum BDNF levels (N = 107), and the BDNF Val66Met genotype (N = 217). Furthermore, we tested the possible interactions between these variables. A significant correlation has been observed between high scores of harm avoidance (HA) measured by the temperament and character inventory (TCI), and low BDNF serum concentration (r = -0.253, P = 0.009). In addition, an association has been evidenced between low BDNF levels in serum and the BDNF Val/Val genotype (P = 0.021). By analyzing putative concomitant effects of different variables on HA scores in a regression model, we observed a significant correlation only with BDNF serum concentrations (P = 0.022). The study results suggest that a decrease in serum BDNF concentrations may represent a biochemical marker associated with anxiety personality traits also retrievable in the general population.

The Alzheimer's Association external quality control program for cerebrospinal fluid biomarkers

BACKGROUND

The cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.

METHODS

The program is open for laboratories using commercially available kits for Aβ, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.

RESULTS

Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure Aβ-(1-42), P-tau(181P), and T-tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN-42, AβN-40, and AβN-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories.

CONCLUSIONS

Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

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.

Alterations of brain-derived neurotrophic factor serum levels in patients with alcohol dependence

BACKGROUND

Alcohol dependence is a chronic relapsing disorder characterized by repetitive alcohol drinking patterns and a loss of control over alcohol consumption. Recent studies have hypothesized that dysregulations in brain neurotrophic support regulated by neurotrophins may be involved in the vulnerability to dependence and in the brain damage caused by chronic alcohol consumption. The neurotrophin brain-derived neurotrophic factor (BDNF) plays a pivotal role in neurodevelopment and in the maintenance of adult brain homeostasis through the regulation of neurogenesis and neuronal plasticity. The role of BDNF and its signaling in the mechanisms of alcohol dependence has been well documented in studies of animal models, but a few studies have been conducted in human peripheral tissues. On the basis of this rationale, we compared BDNF levels in both serum and plasma in alcohol-dependent patients and healthy volunteers.

METHODS

Thirty-seven patients with a principal diagnosis of alcohol dependence were recruited. In parallel, a control group of 37 unrelated volunteers matched for gender and age was enrolled. Serum and plasma BDNF levels were measured by ELISA.

RESULTS

A significant reduction in BDNF serum levels was observed in the patient group compared to healthy subjects (p = 0.028). On the contrary, no difference in BDNF plasma levels was evident between patients and controls.

CONCLUSIONS

In conclusion, our data show an alteration of BDNF peripheral content in patients with alcohol dependence, suggesting the involvement of this neurotrophin in this psychopathology.

Serum and plasma BDNF levels in major depression: a replication study and meta-analyses

OBJECTIVES

Alterations of BDNF signalling in major depression (MD) are supported by studies demonstrating decreased levels of the neurotrophin serum and plasma content in MD patients. We conducted a replication study and we performed two meta-analyses on studies analysing serum and plasma BDNF levels in MD patients.

METHODS

The samples were composed by 489 patients/483 controls for the meta-analysis on serum and by 161 patients/211 controls for that on plasma levels. We performed also subgroup analyses to examine whether the decrease in BDNF levels in MD was influenced by gender.

RESULTS

In the replication study we found decreased serum BDNF levels in MD patients (P<0.01) and we demonstrated that is down-regulated the mature form of the neurotrophin (mBDNF). No significant difference was evidenced for plasma BDNF levels. The meta-analyses showed a reduction of both BDNF serum (P<0.0001) and plasma levels (P=0.02) in MD. No difference in the effect size on serum BDNF was observed between males and females (P=0.18).

CONCLUSIONS

In conclusion, our results provide evidence of peripheral BDNF alteration in MD and support the rationale for further investigation aiming to the identification of biomarkers for differential diagnosis and personalization of therapies in this disorder.

VEGF serum levels in depressed patients during SSRI antidepressant treatment

Recent evidence indicates that the vascular endothelial growth factor (VEGF) may be involved in the neuronal mechanisms underlying both the depression aetiology and the response to pharmacological and non pharmacological antidepressant treatments. To investigate whether VEGF peripheral levels are altered in depression and are modulated by antidepressant therapies, we analyzed the serum VEGF concentrations in 25 subjects affected by major depression (MD) before (T0) and after 8 (T8) and 12 (T12) weeks of escitalopram treatment. No significant alterations in VEGF serum levels were found at T0, even considering possible effects of confounders such as gender and smoking habit (r2=0.227 p=0.74). No changes appeared during the treatment (F(1.83, 43.86)=0.962; p=0.383) and there was no correlation between percentage VEGF variations at T12 and symptoms improvements (p=0.823). The present work represents the first report on the evaluation of serum VEGF levels in MD patients. However, before discarding serum VEGF as a biochemical marker in the diagnosis and treatment of depression, our negative results need to be confirmed in larger patient samples stratified for clinical characteristics, co-morbidities, cardiovascular diseases and confounding factors.

-G308A tumor necrosis factor alpha functional polymorphism and schizophrenia risk: meta-analysis plus association study

Research on -G308A functional polymorphism in the tumor necrosis factor alpha (TNFalpha) gene as a susceptibility factor for schizophrenia has provided contrasting results in different populations. Therefore we conducted a meta-analysis of the published case-control association studies and a replication study in a large sample. Meta-analyses (total sample: 2512 cases versus 3223 controls) showed that the AA genotype was weakly associated with schizophrenia susceptibility in Caucasoids (Odd Ratio OR=1.65, 95% CI=1.00-2.71 Z=1.98 p=0.05). The replication case-control association study (323 DSM-IV-TR schizophrenia patients and 346 controls) showed that the A allele conferred an increased susceptibility for schizophrenia only in males (OR=1.73, 95% CI=1.07-2.79, p=0.025), and the association became more specific when only patients of the paranoid subtype were compared to the controls (relative risk ratio=3.09, 95% CI=1.28-7.47, p=0.012). The presence of the A allele was also associated with a later age at onset of schizophrenia in the whole sample (F(1,291)=7.094, p=0.008). Our results confirm that TNFalpha A allele could have an effect on vulnerability to schizophrenia but further studies revaluating the role of gender and diagnostic subtypes are necessary to confirm these findings.

Electroconvulsive Therapy (ECT) increases serum Brain Derived Neurotrophic Factor (BDNF) in drug resistant depressed patients

Several findings have suggested that the neurotrophin BDNF could contribute to clinical efficacy of antidepressant treatments. The purpose of this study was to analyse if ECT operates a modulation of serum BDNF levels in a sample of drug resistant depressed patients. The results obtained show significantly higher serum levels of BDNF following ECT. More specifically, while no change occurred in the whole sample between T0 (baseline) and T1 (after ECT) (p=0.543) a significant increase has been identified at T2, one month after the end of ECT (p=0.002). However, the BDNF augmentation was evident even between T0 and T1 in a subgroup of patients who has low baseline BDNF levels. Although future researches are needed, the results herein presented show for the first time that ECT is associated with changes in serum BDNF and further support the possible involvement of BDNF in antidepressant therapies.

Effect of repetitive transcranial magnetic stimulation on serum brain derived neurotrophic factor in drug resistant depressed patients

BACKGROUND

Depression has been associated with low brain-derived neurotrophic factor (BDNF) serum levels, while antidepressant drugs appear to mend this alteration. The purpose of this study was to assess BDNF serum levels in drug resistant depressed patients before and after repetitive Transcranial Magnetic Stimulation (rTMS) antidepressant treatment.

METHODS

BDNF levels were measured in serum of 16 resistant depressed patients using the ELISA technique.

RESULTS

BDNF baseline levels showed a negative correlation with illness severity measured by HDRS scores (R = -0.517, p = 0.04) and a significant increase of serum BDNF was found after rTMS treatment (t = -2.549, df = 15, p = 0.022).

CONCLUSIONS

Our findings support the relationship between decreased serum BDNF and depression symptomatology and suggest a normalizing effect of rTMS antidepressant treatment. Further replications in larger samples will help to clarify the relevance of this preliminary data in the rTMS mechanism of action.

Influence of serotonin receptor 2A His452Tyr polymorphism on brain temporal structures: a volumetric MR study

Serotonin (5-HT) receptors 2A are expressed in brain regions involved in memory and learning processes. Recently, a functional single nucleotide polymorphism in the 5-HT2A receptor gene leading to an amino-acid substitution at residue 452 (His452Tyr) has been involved in memory performance, persons with the rare 452Tyr allele showing poorer memory performance compared to His452His subjects. To investigate a putative structural effect of this polymorphism on temporal areas typically involved in memory processes, we performed voxel-based morphometry (VBM) and region-of-interest (ROI) volumetric analysis on high-resolution magnetic resonance images in 15 carriers and 61 noncarriers of the 452Tyr allele. ROI volumetric analysis showed a significant reduction of the fractional volume of the temporal white matter in 452Tyr carriers (0.67+/-0.07 vs 0.73+/-0.08; P=0.007). VBM confirmed this finding and in addition showed reduced grey matter in the left hippocampus, left inferior temporal gyrus, and bilaterally in the middle and superior temporal gyrus. A possible effect on synaptic plasticity or neurodevelopment might explain the influence of the His452Tyr polymorphism on temporal brain structures, and this might be the basis for poorer memory performance in 452Tyr carriers. These findings should be considered preliminary and future replication is needed.

Association study of -1727 A/T, -50 C/T and (CAA)n repeat GSK-3beta gene polymorphisms with schizophrenia

Glycogen synthase kinase-3 (GSK-3) is a downstream component of the Wnt pathway and recent studies have reported abnormal levels of GSK-3beta in schizophrenia. In a sample of 147 schizophrenic patients and 212 healthy individuals, we analyzed two common SNPs at position -1727 A/T and -50 C/T and a (CAA)(n) repeat polymorphism localized in intron 1 of the gene. The results showed that the allele, genotype and haplotype distributions for the three polymorphisms investigated do not differ between schizophrenic patients in general and control subjects. However, in the subtype of paranoid schizophrenic patients, we found that the (CAA)(3)/(CAA)(5) heterozygotes were more often represented. Although taken from a small sample, our results support the reports that GSK-3beta appears to be involved in a subtype of schizophrenic patients, but not in schizophrenia in general. In conclusion, we would speculate that this gene may be linked to some features of psychotic disorders rather than to schizophrenia itself.

Promoter haplotypes of interleukin-10 gene and sporadic Alzheimer's disease

Clinical and immunopathological evidence support a potential role of the pro- and anti-inflammatory cytokine network in neurodegeneration of Alzheimer's disease (AD). Moreover, association studies suggest a possible involvement of cytokine-related genes in the susceptibility to sporadic AD. Since conflicting results are associated with the pro-inflammatory pathway, we investigated a putative effect of the anti-inflammatory counterpart focusing on the interleukin-10 (IL-10) gene. The 5' flanking region contains numerous polymorphisms; in particular, three single nucleotide polymorphisms (-1082 G/A, -819 T/C, -592 C/A) are in linkage disequilibrium resulting in three haplotypes GCC, ACC and ATA. We analyzed the IL-10 haplotype distributions in 215 Italian sporadic AD patients and 153 controls in an association case-control study. Haplotype frequencies did not reveal differences between the two samples, however the genotype GCC/ACC was more represented in AD patients (OR 1.91, 95% CI: 1.18-3.07). This putative risk factor could be independent of the presence of the ApoE epsilon 4 allele. Our results provide new insights on a possible involvement of the IL-10 gene in susceptibility to sporadic AD even though further functional and genetic investigations are necessary to clarify its role in AD.

Association between IL-1beta -511C/T and IL-1RA (86bp)n repeats polymorphisms and schizophrenia

It has been established that cytokines play a critical role in the regulation of the CNS and recent studies have suggested that dysfunctions of both pro-inflammatory (IL-1beta, IL-6, and TNF-alpha) and anti-inflammatory (IL-1RA and IL-10) cytokines could be involved in the pathophysiology of schizophrenia. Previous studies have reported that functional polymorphisms in some cytokines genes may have important regulatory effects on such system. Therefore, the aim of the present study was to explore the possible role of the IL-1beta -511C/T and IL-1RA (86bp)(n) repeats polymorphisms in schizophrenia. A case control association study comparing genotype and allele frequencies in 346 northen Italian subjects (169 schizophrenic patients and 177 unrelated healthy volunteers) was performed. The frequencies of IL-1beta -511C and IL-1RA allele 1 (86bp)(4) are significantly higher in schizophrenic patients compared to controls (IL-1beta -511 P=0.047; IL-1RA (86bp)(n) P=0.002). Moreover our data show a protective effect of the IL-1RA allele 2 (86bp)(2) against schizophrenia (OR=0.59 95%CI:0.388-0.910; P=0.016) and this effect is enhanced by the concomitant presence of IL-1beta -511T (OR=0.48 95%CI:0.30-0.76; P=0.002). Our findings support the hypothesis that genetically determined changes in IL-1 metabolism regulation may contribute to the pathogenesis of schizophrenia confirming a role of IL-1 gene cluster in disease susceptibility.