Anatomical specificity in the modulation of activity-regulated genes after acute or chronic lurasidone treatment

Antipsychotics-Induced Changes in Synaptic Architecture and Functional Connectivity: Translational Implications for Treatment Response and Resistance

Schizophrenia is a severe mental illness characterized by alterations in processes that regulate both synaptic plasticity and functional connectivity between brain regions. Antipsychotics are the cornerstone of schizophrenia pharmacological treatment and, beyond occupying dopamine D2 receptors, can affect multiple molecular targets, pre- and postsynaptic sites, as well as intracellular effectors. Multiple lines of evidence point to the involvement of antipsychotics in sculpting synaptic architecture and remodeling the neuronal functional unit. Furthermore, there is an increasing awareness that antipsychotics with different receptor profiles could yield different interregional patterns of co-activation. In the present systematic review, we explored the fundamental changes that occur under antipsychotics' administration, the molecular underpinning, and the consequences in both acute and chronic paradigms. In addition, we investigated the relationship between synaptic plasticity and functional connectivity and systematized evidence on different topographical patterns of activation induced by typical and atypical antipsychotics.

Lurasidone versus Quetiapine for Cognitive Impairments in Young Patients with Bipolar Depression: A Randomized, Controlled Study

The clinical efficacy of lurasidone and quetiapine, two commonly prescribed atypical antipsychotics for bipolar depression, has been inadequately studied in young patients. In this randomized and controlled study, we aimed to compare the effects of these two drugs on cognitive function, emotional status, and metabolic profiles in children and adolescents with bipolar depression. We recruited young participants (aged 10-17 years old) with a DSM-5 diagnosis of bipolar disorder during a depressive episode, who were then randomly assigned to two groups and treated with flexible doses of lurasidone (60 to 120 mg/day) or quetiapine (300 to 600 mg/day) for consecutive 8 weeks, respectively. All the participants were clinically evaluated on cognitive function using the THINC-it instrument at baseline and week 8, and emotional status was assessed at baseline and the end of week 2, 4, and 8. Additionally, the changes in weight and serum metabolic profiles (triglyceride, cholesterol, and fasting blood glucose) during the trial were also analyzed. In results, a total of 71 patients were randomly assigned to the lurasidone group (n = 35) or the quetiapine group (n = 36), of which 31 patients completed the whole treatment course. After an 8-week follow-up, participants in the lurasidone group showed better performance in the Symbol Check Reaction and Accuracy Tests, when compared to those in the quetiapine group. No inter-group difference was observed in the depression scores, response rate, or remission rate throughout the trial. In addition, there was no significant difference in serum metabolic profiles between the lurasidone group and the quetiapine group, including triglyceride level, cholesterol level, and fasting blood glucose level. However, the quetiapine group presented a more apparent change in body weight than the lurasidone group. In conclusion, the present study provided preliminary evidence that quetiapine and lurasidone had an equivalent anti-depressive effect, and lurasidone appeared to be superior to quetiapine in improving the cognitive function of young patients with bipolar depression.

Present and future antipsychotic drugs: a systematic review of the putative mechanisms of action for efficacy and a critical appraisal under a translational perspective

Antipsychotics represent the mainstay of schizophrenia pharmacological therapy, and their role has been expanded in the last years to mood disorders treatment. Although introduced in 1952, many years of research were required before an accurate picture of how antipsychotics work began to emerge. Despite the well-recognized characterization of antipsychotics in typical and atypical based on their liability to induce motor adverse events, their main action at dopamine D2R to elicit the "anti-psychotic" effect, as well as the multimodal action at other classes of receptors, their effects on intracellular mechanisms starting with receptor occupancy is still not completely understood. Significant lines of evidence converge on the impact of these compounds on multiple molecular signaling pathways implicated in the regulation of early genes and growth factors, dendritic spine shape, brain inflammation, and immune response, tuning overall the function and architecture of the synapse. Here we present, based on PRISMA approach, a comprehensive and systematic review of the above mechanisms under a translational perspective to disentangle those intracellular actions and signaling that may underline clinically relevant effects and represent potential targets for further innovative strategies in antipsychotic therapy.

Contrasting Typical and Atypical Antipsychotic Drugs

The beliefs that antipsychotic drugs (APDs) are 1) effective only to treat delusions and hallucinations (positive symptoms), 2) that typical and atypical APDs differ only in ability to cause extrapyramidal side effects, and 3) that their efficacy as antipsychotics is due solely to their dopamine D₂ receptor blockade are outmoded concepts that prevent clinicians from achieving optimal clinical results when prescribing an APD. Atypical APDs are often more effective than typical APDs in treating negative symptoms, cognitive impairment, and mood symptoms as well as reducing the risk for suicide and decreasing aggression. This applies not only to those diagnosed with schizophrenia or schizoaffective disorder but also to bipolar disorder, major depression, and other psychiatric diagnoses. The greater advantage of an atypical APD is not evident in all patients for every atypical APD due, in part, to individual differences in genetic and epigenetic endowment and differences in the pharmacology of the atypical APDs, their mode of action being far more complex than that of the typical APDs. A common misconception is that among the atypical APDs, only clozapine is effective for reducing psychosis in treatment-resistant schizophrenia. Aripiprazole, lurasidone, olanzapine, and risperidone also can be more effective than typical APDs for treatment-resistant schizophrenia; clozapine is uniquely indicated for reducing the risk for suicide. The ability of the atypical APDs to improve cognition and negative symptoms in some patients together with lower propensity to cause tardive dyskinesia (an underappreciated advantage) leads to better overall outcomes. These advantages of the atypical APDs in efficacy and safety are due, in part, to initiation of synaptic plasticity via direct and indirect effects of the atypical APDs on a variety of proteins, especially G proteins, and release of neurotrophins (e.g., brain-derived neurotrophic factor). The typical APDs beneficial effects on psychosis are mainly the result of D₂ receptor blockade, which can be associated with serious side effects and lack of tolerability.

Towards Novel Treatments for Schizophrenia: Molecular and Behavioural Signatures of the Psychotropic Agent SEP-363856

Schizophrenia is a complex psychopathology whose treatment is still challenging. Given the limitations of existing antipsychotics, there is urgent need for novel drugs with fewer side effects. SEP-363856 (SEP-856) is a novel psychotropic agent currently under phase III clinical investigation for schizophrenia treatment. In this study, we investigated the ability of an acute oral SEP-856 administration to modulate the functional activity of specific brain regions at basal levels and under glutamatergic or dopaminergic-perturbed conditions in adult rats. We found that immediate-early genes (IEGs) expression was strongly upregulated in the prefrontal cortex and, to a less extent, in the ventral hippocampus, suggesting an activation of these regions. Furthermore, SEP-856 was effective in preventing the hyperactivity induced by an acute injection of phencyclidine (PCP), but not of d-amphetamine (AMPH). The compound effectively normalized the PCP-induced increase in IEGs expression in the PFC at all doses tested, whereas only the highest dose determined the major modulations on AMPH-induced changes. Lastly, SEP-856 acute administration corrected the cognitive deficits produced by subchronic PCP administration. Taken together, our data provide further insights on SEP-856, suggesting that modulation of the PFC may represent an important mechanism for the functional and behavioural activity of this novel compound.

Lurasidone Improves Psychopathology and Cognition in Treatment-Resistant Schizophrenia

PURPOSE/BACKGROUND

In addition to clozapine, other atypical antipsychotic drugs pharmacologically similar to clozapine, for example, olanzapine, risperidone, and melperone, are also effective in a similar proportion of treatment-resistant schizophrenia (TRS) patients, ~40%. The major goal of this study was to compare 2 doses of lurasidone, another atypical antipsychotic drug, and time to improvement in psychopathology and cognition during a 6-month trial in TRS patients.

METHODS/PROCEDURES

The diagnosis of TRS was based on clinical history and lack of improvement in psychopathology during a 6-week open trial of lurasidone 80 mg/d (phase 1). This was followed by a randomized, double-blind, 24-week trial of lurasidone, comparing 80- and 240-mg/d doses (phase 2).

FINDINGS/RESULTS

Significant non-dose-related improvement in the Positive and Negative Syndrome Scale-Total and subscales and in 2 of 7 cognitive domains, speed of processing and executive function, were noted. Twenty-eight (41.8%) of 67 patients in the combined sample improved ≥20% in the Positive and Negative Syndrome Scale-Total. Of the 28 responders, 19 (67.9%) first reached ≥20% improvement between weeks 6 and 24 during phase 2, including some who had previously failed to respond to clozapine.

IMPLICATIONS/CONCLUSIONS

Improvement with lurasidone is comparable with those previously reported for clozapine, melperone, olanzapine, and risperidone in TRS patients. In addition, this study demonstrated that 80 mg/d lurasidone, an effective and tolerable dose for non-TRS patients, was also effective in TRS patients but required longer duration of treatment. Direct comparison of lurasidone with clozapine in TRS patients is indicated.

FoxO1, A2M, and TGF-β1: three novel genes predicting depression in gene X environment interactions are identified using cross-species and cross-tissues transcriptomic and miRNomic analyses

To date, gene-environment (GxE) interaction studies in depression have been limited to hypothesis-based candidate genes, since genome-wide (GWAS)-based GxE interaction studies would require enormous datasets with genetics, environmental, and clinical variables. We used a novel, cross-species and cross-tissues "omics" approach to identify genes predicting depression in response to stress in GxE interactions. We integrated the transcriptome and miRNome profiles from the hippocampus of adult rats exposed to prenatal stress (PNS) with transcriptome data obtained from blood mRNA of adult humans exposed to early life trauma, using a stringent statistical analyses pathway. Network analysis of the integrated gene lists identified the Forkhead box protein O1 (FoxO1), Alpha-2-Macroglobulin (A2M), and Transforming Growth Factor Beta 1 (TGF-β1) as candidates to be tested for GxE interactions, in two GWAS samples of adults either with a range of childhood traumatic experiences (Grady Study Project, Atlanta, USA) or with separation from parents in childhood only (Helsinki Birth Cohort Study, Finland). After correction for multiple testing, a meta-analysis across both samples confirmed six FoxO1 SNPs showing significant GxE interactions with early life emotional stress in predicting depressive symptoms. Moreover, in vitro experiments in a human hippocampal progenitor cell line confirmed a functional role of FoxO1 in stress responsivity. In secondary analyses, A2M and TGF-β1 showed significant GxE interactions with emotional, physical, and sexual abuse in the Grady Study. We therefore provide a successful 'hypothesis-free' approach for the identification and prioritization of candidate genes for GxE interaction studies that can be investigated in GWAS datasets.

Immediate-Early Genes Modulation by Antipsychotics: Translational Implications for a Putative Gateway to Drug-Induced Long-Term Brain Changes

An increasing amount of research aims at recognizing the molecular mechanisms involved in long-lasting brain architectural changes induced by antipsychotic treatments. Although both structural and functional modifications have been identified following acute antipsychotic administration in humans, currently there is scarce knowledge on the enduring consequences of these acute changes. New insights in immediate-early genes (IEGs) modulation following acute or chronic antipsychotic administration may help to fill the gap between primary molecular response and putative long-term changes. Moreover, a critical appraisal of the spatial and temporal patterns of IEGs expression may shed light on the functional "signature" of antipsychotics, such as the propensity to induce motor side effects, the potential neurobiological mechanisms underlying the differences between antipsychotics beyond D2 dopamine receptor affinity, as well as the relevant effects of brain region-specificity in their mechanisms of action. The interest for brain IEGs modulation after antipsychotic treatments has been revitalized by breakthrough findings such as the role of early genes in schizophrenia pathophysiology, the involvement of IEGs in epigenetic mechanisms relevant for cognition, and in neuronal mapping by means of IEGs expression profiling. Here we critically review the evidence on the differential modulation of IEGs by antipsychotics, highlighting the association between IEGs expression and neuroplasticity changes in brain regions impacted by antipsychotics, trying to elucidate the molecular mechanisms underpinning the effects of this class of drugs on psychotic, cognitive and behavioral symptoms.

Lurasidone versus treatment as usual for cognitive impairment in euthymic patients with bipolar I disorder: a randomised, open-label, pilot study

BACKGROUND

Cognitive impairment is present in euthymic patients with bipolar disorder and correlates with impairments in everyday functioning. We aimed to examine the efficacy of lurasidone adjunctive therapy compared with treatment as usual (TAU) in improving cognition.

METHODS

For this randomised, open-label, pilot study, we recruited patients aged 19-65 years with euthymic bipolar I disorder from the Mood Disorder Centre in UBC Hospital (Vancouver, Canada). We included patients who were taking lithium, or valproate, or an atypical antipsychotic, or a combination of these for mood stabilisation and who showed reduced cognitive functioning (SD≤ -0·25 relative to demographics-corrected norms) on either the Trail Making Test-B or the California Verbal Learning Test-II. Patients were randomly assigned using a randomised block design with a block size of four to TAU or lurasidone adjunctive therapy (20-80 mg/day) for 6 weeks. A research coordinator masked to group allocation administered the International Society for Bipolar Disorders Battery for Assessment of Neurocognition (ISBD-BANC) at baseline and at endpoint. The primary outcome was change in global cognition score, which consisted of the mean demographics-corrected t-score value of the several ISBD-BANC measures, analysed in all patients who completed both tests. This trial is registered on ClinicalTrials.gov, number NCT02147379.

FINDINGS

Between July 2, 2014, and Oct 19, 2015, 34 patients were randomly allocated to lurasidone adjunctive therapy (17 patients) or TAU (17 patients). Two patients from each group did not complete the study. The mean lurasidone dose was 48·24 (SD 15·90) mg/day. Lurasidone adjunctive therapy was more effective than TAU in improving the primary efficacy measure of ISBD-BANC global cognition score (mean difference 2·92 [95% CI 0·27-5·57]; time × treatment interaction F=5·09; p=0·032). The between-group effect size (0·82) on baseline versus study-end difference scores in the ISBD global cognition score was of moderate to large magnitude. The magnitude of benefit with lurasidone adjunctive therapy in improving global cognition (effect size 0·46) was greater compared with the improvement observed in the TAU group (0·04). Adverse events were reported by nine (60%) patients in the luradisone group and two (13%) in the TAU group.

INTERPRETATION

Our results provide some preliminary evidence for the efficacy of lurasidone in improving cognition in euthymic patients with bipolar I disorder. The strengths of this study were the characterisation of the sample and use of tests sensitive to cognitive impairment in bipolar disorder. Its limitations were the sample size and inability to completely control for other medication use. Larger double-blind trials are warranted to investigate this further.

FUNDING

Sumitomo Dainippon Pharma.

Chronic lurasidone treatment normalizes GABAergic marker alterations in the dorsal hippocampus of mice exposed to prenatal immune activation

Prenatal maternal infection represents a risk factor for the development of psychopathologic conditions later in life. Clinical evidence is also supported by animal models in which the vulnerability to develop a schizophrenic-like phenotype likely originates from inflammatory processes as early as in the womb. Prenatal immune challenge, for example, induces a variety of long-term behavioral alterations in mice, such as deficits in recognition and spatial working memory, perseverative behaviors and social impairments, which are relevant to different symptom clusters of schizophrenia. Here, we investigated the modulation of GABAergic markers in the dorsal and ventral hippocampus of adult mice exposed to late prenatal immune challenge with the viral mimetic Poly(I:C) (polyriboinosinic-polyribocytidilic-acid) at gestational day 17, and we evaluated the ability of chronic treatment with the multi-receptor antipsychotic lurasidone to modulate the alterations produced by maternal infection. Poly(I:C) mice show a significant reduction of key GABAergic markers, such as GAD67 and parvalbumin, specifically in the dorsal hippocampus, which were normalized by chronic lurasidone administration. Moreover, chronic drug administration increases the expression of the pool of brain derived neurotrophic factor (BDNF) transcripts with the long 3'-UTR as well as the levels of mature BDNF protein in the synaptosomal compartment, selectively in dorsal hippocampus. All in all, our findings demonstrate that lurasidone is effective in ameliorating molecular abnormalities observed in Poly(I:C) mice, providing further support to the neuroplastic properties of this multi-receptor antipsychotic drug.

Chronic mild stress-induced alterations of clock gene expression in rat prefrontal cortex: modulatory effects of prolonged lurasidone treatment

Disruptions of biological rhythms are known to be associated with depressive disorders, suggesting that abnormalities in the molecular clock may contribute to the development of these disorders. These mechanisms have been extensively characterized in the suprachiasmatic nucleus, but little is know about the role exerted by individual clock genes in brain structures that are important for depressive disorders. Using the chronic mild stress model we found a significant reduction of BMAL1 and CLOCK protein levels in the nuclear compartment of the prefrontal cortex of CMS rats, which was paralleled by a down-regulation of the expression of several target genes, including Pers and Crys but also Reverbβ and Pparα. Interestingly, chronic treatment with the multi receptor modulator lurasidone (3mg/kg for 5 weeks) was able to normalize the molecular changes induced by CMS exposure in prefrontal cortex, but it was also able to regulate some of these genes within the hippocampus. We believe that changes in clock genes expression after CMS exposure may contribute to the disturbances associated with depressive disorders and that the ability of chronic lurasidone to normalize such alterations may be relevant for its therapeutic properties in ameliorating functions that are deteriorated in patients with major depression and other stress-related disorders.

Lurasidone and fluoxetine reduce novelty-induced hypophagia and NMDA receptor subunit and PSD-95 expression in mouse brain

Lurasidone, a novel second-generation antipsychotic agent, exerts antidepressant actions in patients suffering from bipolar type I disorder. Lurasidone acts as a high affinity antagonist at multiple monoamine receptors, particularly 5-HT2A, 5-HT7, D2 and α2 receptors, and as a partial agonist at 5-HT1A receptors. Accumulating evidence indicates therapeutic actions by monoaminergic antidepressants are mediated via alterations of glutamate receptor-mediated neurotransmission. Here, we used mice and investigated the effects of chronic oral administration of vehicle, lurasidone (3 or 10mg/kg) or fluoxetine (20mg/kg) in the novelty induced hypophagia test, a behavioral test sensitive to chronic antidepressant treatment. We subsequently performed biochemical analyses on NMDA receptor subunits and associated proteins. Both lurasidone and fluoxetine reduced the latency to feed in the novelty-induced hypophagia test. Western blotting experiments showed that both lurasidone and fluoxetine decreased the total levels of NR1, NR2A and NR2B subunits of NMDA receptors and PSD-95 (PostSynaptic Density-95) in hippocampus and prefrontal cortex. Taken together, these data indicate that antidepressant/anxiolytic-like effects of lurasidone, as well as fluoxetine, could involve reduced NMDA receptor-mediated signal transduction, particularly in pathways regulated by PSD-95, in hippocampus and prefrontal cortex.