Network analysis of gene expression in peripheral blood identifies mTOR and NF-κB pathways involved in antipsychotic-induced extrapyramidal symptoms

To identify the candidate genes for pharmacogenetic studies of antipsychotic (AP)-induced extrapyramidal symptoms (EPS), we propose a systems biology analytical approach, based on protein-protein interaction network construction and functional annotation analysis, of changes in gene expression (Human Genome U219 Array Plate) induced by treatment with risperidone or paliperidone in peripheral blood. 12 AP-naïve patients with first-episode psychosis participated in the present study. Our analysis revealed that, in response to AP treatment, constructed networks were enriched for different biological processes in patients without EPS (ubiquitination, protein folding and adenosine triphosphate (ATP) metabolism) compared with those presenting EPS (insulin receptor signaling, lipid modification, regulation of autophagy and immune response). Moreover, the observed differences also involved specific pathways, such as anaphase promoting complex /cdc20, prefoldin/CCT/triC and ATP synthesis in no-EPS patients, and mammalian target of rapamycin and NF-κB kinases in patients with EPS. Our results showing different patterns of gene expression in EPS patients, offer new and valuable markers for pharmacogenetic studies.

Profile of paliperidone palmitate once-monthly long-acting injectable in the management of schizophrenia: long-term safety, efficacy, and patient acceptability - a review

BACKGROUND AND OBJECTIVES

Short-term studies focused on once-monthly paliperidone palmitate (PP) at doses of 25 mg eq, 50 mg eq, 75 mg eq, 100 mg eq, or 150 mg eq have shown its efficacy and tolerability in the treatment of schizophrenia patients. However, few open-label and long-term studies are available regarding this new pharmacological formulation. Thus, our main aim was to review the scientific evidence on efficacy, safety, tolerability, and preference of PP in these populations.

METHOD

Electronic searches were conducted by using PubMed and ISI Web of Knowledge databases. All relevant studies published from 2009 until January 2015 were included without any language restriction if patients met diagnostic criteria for schizophrenia, and adequate information on efficacy, safety, and tolerability of once-monthly PP was available.

RESULTS

Nineteen studies were identified irrespective of the study design and duration of the follow-up period. Randomized, double-blind, placebo-controlled trials found that schizophrenia patients receiving PP showed a significant improvement in psychotic symptoms and similar adverse events compared to placebo and suggested that all doses of PP were efficacious and well tolerated. Other studies demonstrated noninferiority of PP compared to risperidone long-acting injectable in recently diagnosed schizophrenia patients, chronically ill patients, as well as in acute and nonacute symptomatic schizophrenia patients, and a similar proportion of treatment-emergent adverse events between both groups were also noted.

CONCLUSION

Several studies have demonstrated that schizophrenia patients treated with PP show higher rates of improvement of psychotic symptoms compared to placebo, and similar efficacy and tolerability outcomes were noted when comparing PP to risperidone long-acting injectable or oral, paliperidone extended release.

Brain metabolism during hallucination-like auditory stimulation in schizophrenia

Auditory verbal hallucinations (AVH) in schizophrenia are typically characterized by rich emotional content. Despite the prominent role of emotion in regulating normal perception, the neural interface between emotion-processing regions such as the amygdala and auditory regions involved in perception remains relatively unexplored in AVH. Here, we studied brain metabolism using FDG-PET in 9 remitted patients with schizophrenia that previously reported severe AVH during an acute psychotic episode and 8 matched healthy controls. Participants were scanned twice: (1) at rest and (2) during the perception of aversive auditory stimuli mimicking the content of AVH. Compared to controls, remitted patients showed an exaggerated response to the AVH-like stimuli in limbic and paralimbic regions, including the left amygdala. Furthermore, patients displayed abnormally strong connections between the amygdala and auditory regions of the cortex and thalamus, along with abnormally weak connections between the amygdala and medial prefrontal cortex. These results suggest that abnormal modulation of the auditory cortex by limbic-thalamic structures might be involved in the pathophysiology of AVH and may potentially account for the emotional features that characterize hallucinatory percepts in schizophrenia.

Increased susceptibility to apoptosis in cultured fibroblasts from antipsychotic-naïve first-episode schizophrenia patients

Altered apoptosis has been proposed as a potential mechanism involved in the abnormal neurodevelopment and neurodegenerative processes associated with schizophrenia. The aim of this study was to investigate in primary fibroblast cultures whether antipsychotic-naïve patients with first-episode schizophrenia have greater apoptotic susceptibility than healthy controls. Cell growth, cell viability and various apoptotic hallmarks (caspase-3 activity, translocation of phosphatidylserine, chromatin condensation and gene expression of AKT1, BAX, BCL2, CASP3, GSK3B and P53) were measured in fibroblast cultures obtained from skin biopsies of patients (n = 11) and healthy controls (n = 8), both in basal conditions and after inducing apoptosis with staurosporine. Compared to controls, cultured fibroblasts from patients showed higher caspase-3 activity and lower BCL2 expression. When exposed to staurosporine, fibroblasts from patients also showed higher caspase-3 activity; a higher percentage of cells with translocated phosphatidylserine and condensed chromatin; and higher p53 expression compared to fibroblasts from controls. No differences in cell viability or cell growth were detected. These results strongly support the hypothesis that first-episode schizophrenia patients may have increased susceptibility to apoptosis, which may be involved in the onset and progression of the disease.

Amélioration fonctionnelle sous palmitate de paliperidone à doses flexibles chez des patients aigus ou non aigus atteints de schizophrénie, après échec d’un traitement par antipsychotiques oraux

Objectifs

Évaluer l’amélioration fonctionnelle chez des patients atteints de schizophrénie sous palmitate de paliperidone (PP) à doses flexibles après échec d’un traitement par antipsychotiques oraux.

Méthodes

Analyse menée dans deux sous-groupes de patients atteints de schizophrénie : aigus (n = 202) et non aigus (n = 593) après échec d’un traitement par antipsychotiques oraux, inclus dans une étude internationale, prospective, de six mois.

Critères d’évaluation

Changement du score total à la PANSS (Positive and Negative Syndrome Scale), à la PSP (Personal and Psychosocial Performance scale), et à la Mini-ICF-APP (Mini International Classification of Functionality, Disability and Health Rating for Activity and Participation Disorders in Psychological Illnesses).

Résultats

Les deux sous-groupes ont présenté une amélioration significative du score total à la PANSS : de 98,5 ± 20,1 à l’inclusion à 67,4 ± 24,0 à la fin de l’étude (diminution moyenne = −31,0 ± 29,0) chez les patients aigus et de 71,5 ± 14,6 à 59,7 ± 18,1 (diminution moyenne = −11,7 ± 15,9) chez les patients non aigus. Cette réponse thérapeutique était associée à une augmentation significative du score total à la PSP de 43,9 ± 15,0 à 62,9 ± 17,1 (amélioration moyenne = 19,0 ± 18,7, p <0,0001) chez les patients aigus, et de 58,1 ± 13,4 à 66,1 ± 15,7 (amélioration moyenne =8,0 ± 14,0, p < 0,0001) chez les patients non aigus. Il existait une amélioration significative du score à la Mini-ICF-APP qui diminuait de 26,8 ± 8,5 à 18,5 ± 9,8 (diminution moyenne = −8,0 ± 10,4, p < 0,0001) chez les patients aigus et de 19,8 ± 7,9 à 15,9 ± 8,8 (diminution moyenne = −4,0 ± 7,5, p < 0,0001) chez les patients non aigus.

Conclusions

L’amélioration symptomatique sous PP à doses flexibles chez des patients aigus ou non-aigus atteints de schizophrénie après échec d’un traitement par antipsychotique oral s’est accompagnée d’une amélioration fonctionnelle cliniquement significative.

Palmitate de palipéridone à doses flexibles – Réponse thérapeutique, tolérance et sécurité d’emploi: une étude prospective chez des patients en période d’exacerbation aiguë d’un trouble schizophrénique après échec d’un traitement par antipsychotiques oraux

Objectifs

Évaluer la tolérance, la sécurité d’emploi et l’efficacité de doses flexibles de PP chez des patients adultes en période d’exacerbation aiguë d’une schizophrénie, après échec d’un traitement par antipsychotiques oraux.

Méthodes

Étude internationale, prospective, ouverte, de six mois.

Critères d’évaluation

Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), événements indésirables (EI), changement de poids.

Résultats

Deux cent douze patients (population en intention de traiter) : âge moyen 36,4 ± 12,1 ans, 59,0 % d’hommes, 85,4 % souffrant de schizophrénie paranoïde ont été inclus. La principale raison de la substitution d’un antipsychotique oral par le PP était un manque d’efficacité (45,8 %). 70,3 % des patients ont terminé l’étude de six mois. Les raisons les plus fréquentes d’arrêt précoce ont été : le choix du patient (9,4 %), des EI (9,0 %), les perdus de vue (4,7 %), le manque d’efficacité (2,8 %). Le score total moyen à la PANSS initiale (98,5 ± 20,1) a diminué, et ce dès j8, pour atteindre 67,4 ± 24,0 à la fin de l’étude (diminution de −31,0 ± 29,0, p < 0,0001). 66,7 % des patients ont eu une amélioration de plus de 30 % du score PANSS total et le pourcentage de patients jugés manifestement malades ou pire (CGI-S) a diminué de 75,1 % à 20,5 %. Les EIs (≥ 5 % patients) : douleur au site d’injection (13,7 %), insomnie (10,8 %), trouble psychotique (10,4 %), céphalées (6,1 %) et anxiété (6,1 %). Le changement moyen de poids a été de 2,6 ± 5,6 kg (IC 95 % [1,8; 3,4]).

Conclusions

Ces résultats confirment que le PP à doses flexibles est bien toléré et permet une réponse clinique précoce et cliniquement significative chez des patients en période d’exacerbation aiguë de leur trouble schizophrénique, après échec d’un traitement par antipsychotiques oraux.

Screening for substance use disorders in first-episode psychosis: implications for readmission

INTRODUCTION

Screening of substance use may prove useful to prevent readmission after the first episode of psychosis. The aim of the present study was to evaluate the influence of drug use on readmission risk in a first-episode psychosis sample, and to determine whether the cannabis/cocaine subscale of the Dartmouth Assessment of Lifestyle Inventory (DALI) is a better predictive instrument than urinary analysis.

METHODS

After admission, first-episode psychotic patients were interviewed for substance use and assessed with the DALI scale. They also underwent blood and urine sampling. Time to readmission was studied as a dependent outcome. The Kaplan-Meier estimator was applied to estimate the survival curves for bivariate analysis. The Cox proportional hazards model for multivariate analysis was assessed in order to control for potential confounders. ROC curve and validity parameters were used to assess validity to detect readmission.

RESULTS

Fifty-eight patients were included. The DALI cannabis/cocaine subscale and urinalysis were associated with increased readmission risk in survival curves, mainly the first five years of follow-up. After controlling for potential confounding variables for readmission, only the DALI cannabis/cocaine subscale remained as a significant risk factor. In terms of validity, the DALI cannabis/cocaine subscale was more sensitive than urinalysis. Alcohol assessments were not related to readmission.

CONCLUSIONS

The findings demonstrated that a quick screening self-report scale for cannabis/cocaine use disorders is superior to urinary analysis for predicting readmission. Future research should consider longitudinal assessments of brief validated screening tests in order to evaluate their benefits in preventing early readmission in first-episode psychosis.

Neurotoxic/neuroprotective activity of haloperidol, risperidone and paliperidone in neuroblastoma cells

The neurotoxicity of antipsychotic (AP) drugs seems to be linked with neurological side effects like extrapyramidal symptoms (EPS). On the other hand, neuroprotective effects can mitigate or slow the progressive degenerative structural changes in the brain leading to improved outcome of schizophrenia. First and second-generation antipsychotics may differ in their neurotoxic and neuroprotective properties. The aim of this study was to compare the neurotoxic/neuroprotective activity of haloperidol, a first-generation antipsychotic, and risperidone, a second-generation one, with paliperidone, a relatively new second-generation antipsychotic, in SK-N-SH cells. Haloperidol, risperidone and paliperidone (10, 50, 100 μM) were administered, either alone or in combination with dopamine (100 μM), to human neuroblastoma SK-N-SH. We examined the effects of the drugs on cell viability (measured by alamarBlue®), caspase-3 activity (measured by fluorimetric assay) and cell death (by measuring the externalization of phosphatidylserine). Haloperidol significantly decreased cell viability and increased caspase-3 activity and cell death. Risperidone and paliperidone did not affect cell viability or cell death. Both second-generation APs decreased caspase-3 activity, especially paliperidone. In cells treated with dopamine in combination with antipsychotics, only paliperidone (10 μM) induced a slight improvement in cell viability. While haloperidol potentiated the dopamine-induced increase in caspase-3 activity, risperidone and paliperidone reduced this effect. The results indicate that haloperidol induces apoptosis, whereas risperidone and paliperidone may afford protection against it. Of the APs tested, paliperidone always showed the strongest neuroprotective effect. The different antipsychotic effects on survival and cell death might be related to differences in their capacity to induce EPS.

A 4-year dopamine transporter (DAT) imaging study in neuroleptic-naive first episode schizophrenia patients

Alterations in the dopaminergic system have long been implicated in schizophrenia. A key component in dopaminergic neurotransmission is the striatal dopamine transporter (DAT). To date, there have been no longitudinal studies evaluating the course of DAT in schizophrenia. A 4-year follow-up study was therefore conducted in which single photon emission computed tomography was used to measure DAT binding in 14 patients and 7 controls. We compared the difference over time in [(123)I] FP-CIT striatal/occipital uptake ratios (SOUR) between patients and controls and the relationship between this difference and both symptomatology and functional outcome at follow-up. We also calculated the relationship between baseline SOUR, symptoms and functional outcome at follow-up. There were no statistically significant differences between patients' SOUR changes over time and those of controls. A significant negative correlation was observed between patients' SOUR changes over time and negative symptomatology at follow-up. A significant negative correlation was also found between baseline SOUR in patients and negative symptomatology, and there was a significant association between lower SOUR at baseline and poor outcome. Although the study found no overall differences in DAT binding during follow-up between schizophrenia patients and controls, it demonstrated that differences in DAT binding relate to patients' characteristics at follow-up.

Differential brain glucose metabolic patterns in antipsychotic-naïve first-episode schizophrenia with and without auditory verbal hallucinations

BACKGROUND

Auditory verbal hallucinations (AVHs) are a core symptom of schizophrenia. Previous reports on neural activity patterns associated with AVHs are inconsistent, arguably owing to the lack of an adequate control group (i.e., patients with similar characteristics but without AVHs) and neglect of the potential confounding effects of medication.

METHODS

The current study was conducted in a homogeneous group of patients with schizophrenia to assess whether the presence or absence of AVHs was associated with differential regional cerebral glucose metabolic patterns. We investigated differences between patients with commenting AVHs and patients without AVHs among a group of dextral antipsychotic-naive inpatients with acute first-episode schizophrenia examined with [(18)F]fluoro-deoxyglucose positron emission tomography (FDG-PET) at rest. Univariate and multivariate approaches were used to establish between-group differences.

RESULTS

We included 9 patients with AVHs and 7 patients without AVHs in this study. Patients experiencing AVHs during FDG uptake had significantly higher metabolic rates in the left superior and middle temporal cortices, bilateral superior medial frontal cortex and left caudate nucleus (cluster level p < 0.005, family wise error-corrected, and bootstrap ratio > 3.3, respectively). Additionally, the multivariate method identified hippocampal-parahippocampal, cerebellar and parietal relative hypoactivity during AVHs in both hemispheres (bootstrap ratio < -3.3).

LIMITATIONS

The FDG-PET imaging technique does not provide information regarding the temporal course of neural activity. The limited sample size may have increased the risk of false-negative findings.

CONCLUSION

Our results indicate that AVHs in patients with schizophrenia may be mediated by an alteration of neural pathways responsible for normal language function. Our findings also point to the potential role of the dominant caudate nucleus and the parahippocampal gyri in the pathophysiology of AVHs. We discuss the relevance of phenomenology-based grouping in the study of AVHs.

Searching for functional SNPs or rare variants in exonic regions of DRD3 in risperidone-treated patients

Previously one intronic DRD3 SNP, rs167771, was associated with risperidone-induced extrapyramidal side-effects (EPS). The aim of the present study was to search hitherto unidentified common functional variants or rare variants, in DRD3 associated with risperidone-induced EPS. 126 subjects treated with risperidone participated in this study. We sequenced the seven exons of DRD3. After sequencing we localized five dbSNPs and four new rare variants. None of the dSNPs or rare variants seems to be functional after bioinformatics analysis. Our results suggest that, rather than exonic regions, regulatory regions and introns could be related to the associations reported for DRD3 and the incidence of locomotor side-effects.

Remission and functioning after two years undergoing Long-Acting Injectable Risperidone (LAIR) in recent-onset schizophrenia

Introduction

Improving adherence in the early stages of illness by means of long-acting antipsychotics can lead to reduced number of readmissions and enhanced remission rates, which could lead to improved performance in the medium-long term.

Objectives

Assessing clinical remission, number of admissions and personal and social performance in recent-onset schizophrenic patients undergoing LAIR.

Methods

Longitudinal retrospective study of a cohort of thirty-one recent-onset schizophrenic patients ( ≤ 2 years) who started LAIR treatment between 2004–2008. Twenty-six (83.9%) were treated for two years. PANSS scale was assessed at baseline; PANSS, Personal and Social Performance scale (PSP) and remission criteria after two years.

Results

Twenty-six patients (83.9%), 61.5% male aged between 16–44 years old, completed two years of treatment. All patients met criteria for schizophrenia (DSM-IV) with an average duration of 0.8 year since diagnosis. The main reason to using LAIR was poor adherence (76.9%). The PANSS total and all its subscale scores improved significantly (p < 0.005) with 80.8% of patients showing a ≥ 50% improvement on the PANSS total. Seventeen patients (65.4%) achieved remission criteria. Five patients (19.2%) were admitted during the follow-up. The average on global functioning (PSP) was 72.4 (IC 95%, 66.4-78.4). LAIR doses at baseline were 25 mg (46.2%), 37.5 mg (30.8%) or 50 mg (23.1%); after two years, 25 mg (34.6%), 37.5 mg (34.6%), 50 mg (23.1%) or 75 mg (7.7%).

Conclusions

Despite the limitation of retrospective observational studies, our data, including the good adherence rate (83.9%), suggest that LAIR could be effective in the treatment of recent-onset schizophrenia.

Intuitive pharmacogenetics: spontaneous risperidone dosage is related to CYP2D6, CYP3A5 and ABCB1 genotypes

The aim of this study is to evaluate whether the quantitative prescription of risperidone (dosage) is related to the patient's metabolic status. Metabolic status was defined in terms of the most relevant polymorphisms of CYP2D6 (*3, *4, *5, *6 and *1xN), CYP3A5 (*3A) and ABCB1 (G2677T) determined a posteriori and blinded to the clinicians. This prospective and observational study includes a cohort of 151 Caucasian psychiatric patients treated with risperidone. Significant differences (Kruskal-Wallis test p=0.01) among the doses administered were observed to correlate (Spearman's r=1, p=0.02) with the different CYP2D6 groups. Poor metabolizers received the lowest doses and ultra rapid metabolizers the highest. No significant correlations were observed with regard to CYP3A5 and ABCB1. We find that, despite not knowing patients' metabolic status, clinicians modify risperidone dosage in order to obtain the best therapeutic option.

Lack of association between antipsychotic-induced extrapyramidal symptoms and polymorphisms in dopamine metabolism and transport genes

The purpose of this study was to investigate the relationship between functional polymorphisms in genes coding for dopamine metabolism and transport enzymes and the incidence of acute antipsychotic (AP)-induced extrapyramidal symptoms (EPS). We did not find evidence of the involvement of these polymorphisms in the predisposition towards or protection from EPS.

Progressive gray matter changes in first episode schizophrenia: a 4-year longitudinal magnetic resonance study using VBM

Schizophrenia is a disabling illness, characterized by a heterogeneous course including clinical deterioration and poor outcome. Accumulating findings in schizophrenia suggest that it might involve two pathophysiologic processes, one early in life (neurodevelopmental), and one after onset of the illness (neurodegenerative). Longitudinal imaging studies after onset of the illness may help to clarify these pathophysiological aspects of schizophrenia, but so far, probably due to methodological differences, there have been no conclusive results. The present study sets out to investigate longitudinal gray matter changes in patients with first-episode schizophrenia relative to healthy subjects over the first 4 years of the illness and the relation of gray matter changes in patients with functional outcome, using an objective automatic method not biased to one particular structure to analyze gray matter changes.

METHODS

We included 28 first-episode neuroleptic-naïve patients with DSM-IV diagnosis of schizophreniform disorder or schizophrenia, and 17 controls. 15 patients and 11 controls completed the longitudinal study and were reevaluated after four years. Gray matter changes over time were measured with voxel-based morphometry (VBM) using SPM5. Functional outcome was measured with the global assessment functioning scale (GAF).

RESULTS

Excessive decrease in gray matter was found in patients as compared to healthy individuals in the left superior temporal gyrus and right orbitofrontal gyrus, and excessive increase in the bilateral lingual gyrus and right cuneus. Additionally, gray matter changes in patients in the left lingual gyrus, right insula and right cerebellum, were inversely related to functional outcome (p<0.001 uncorrected at voxel level, p<0.05 family-wise-error corrected at cluster level).

CONCLUSIONS

There are differing longitudinal gray matter changes in patients with schizophrenia during the first years of the illness as compared to healthy individuals. Some progressive gray matter changes in patients are related to functional outcome.