Oxidative-Antioxidant Imbalance and Impaired Glucose Metabolism in Schizophrenia

Increased cell-free DNA is associated with oxidative damage in patients with schizophrenia

Cell-free DNA (cfDNA) has been found to be elevated in patients with schizophrenia (SZ), potentially derived from activated apoptosis, but the underlying mechanisms remain unknown. Moreover, whether the concentrations of cfDNA are altered with disease stage has not been investigated, which limits its clinical application as an auxiliary diagnostic marker for SZ. Using an improved fluorescence correlation spectroscopy (FCS) method that does not require DNA extraction, we measured the molar concentrations of cfDNA in plasma samples of 191 patients with SZ, 78 patients with mood disorders (MD) and 65 healthy controls (HC). We also analyzed the cfDNA composition from either the nucleus or mitochondria, oxidation markers and biochemical indexes to explore the potential mechanistic associations of the increased cfDNA levels. We found that in SZ patients, the cfDNA levels were significantly increased (P = 0.003) regardless of the different disease stages or antipsychotic medication use. Furthermore, qPCR revealed that cell-free nuclear DNA (cf-nDNA) (P = 0.041) but not cell-free mitochondrial DNA (cf-mtDNA) was elevated in SZ patients. Moreover, decreased SOD activity in SZ patients (P = 0.005) was negatively correlated with cfDNA levels (P = 0.047), and fasting blood glucose was positively correlated with cfDNA levels in SZ patients (P = 0.013). Our study provides evidence to support that the elevated cfDNA may be a convenient, effective and stable trait indicator of SZ. Further analysis showed that it mainly came from nucleus, suggesting increased apoptosis, and potentially related to oxidative stress and high blood glucose levels in patients.

A network of transcriptomic signatures identifies novel comorbidity mechanisms between schizophrenia and somatic disorders

The clinical burden of mental illness, in particular schizophrenia and bipolar disorder, are driven by frequent chronic courses and increased mortality, as well as the risk for comorbid conditions such as cardiovascular disease and type 2 diabetes. Evidence suggests an overlap of molecular pathways between psychotic disorders and somatic comorbidities. In this study, we developed a computational framework to perform comorbidity modeling via an improved integrative unsupervised machine learning approach based on multi-rank non-negative matrix factorization (mrNMF). Using this procedure, we extracted molecular signatures potentially explaining shared comorbidity mechanisms. For this, 27 case-control microarray transcriptomic datasets across multiple tissues were collected, covering three main categories of conditions including psychotic disorders, cardiovascular diseases and type II diabetes. We addressed the limitation of normal NMF for parameter selection by introducing multi-rank ensembled NMF to identify signatures under various hierarchical levels simultaneously. Analysis of comorbidity signature pairs was performed to identify several potential mechanisms involving activation of inflammatory response auxiliarily interconnecting angiogenesis, oxidative response and GABAergic neuro-action. Overall, we proposed a general cross-cohorts computing workflow for investigating the comorbid pattern across multiple symptoms, applied it to the real-data comorbidity study on schizophrenia, and further discussed the potential for future application of the approach.

Neuronal alterations in AKT isotype expression in schizophrenia

Schizophrenia is characterized by substantial alterations in brain function, and previous studies suggest insulin signaling pathways, particularly involving AKT, are implicated in the pathophysiology of the disorder. This study demonstrates elevated mRNA expression of AKT1-3 in neurons from schizophrenia subjects, contrary to unchanged or diminished total AKT protein expression reported in previous postmortem studies, suggesting a potential decoupling of transcript and protein levels. Sex-specific differential AKT activity was observed, indicating divergent roles in males and females with schizophrenia. Alongside AKT, upregulation of PDPK1, a critical component of the insulin signaling pathway, and several protein phosphatases known to regulate AKT were detected. Moreover, enhanced expression of the transcription factor FOXO1, a regulator of glucose metabolism, hints at possible compensatory mechanisms related to insulin signaling dysregulation. Findings were largely independent of antipsychotic medication use, suggesting inherent alterations in schizophrenia. These results highlight the significance of AKT and related signaling pathways in schizophrenia, proposing that these changes might represent a compensatory response to a primary defect of conical insulin signaling pathways. This research underscores the need for a detailed understanding of these signaling pathways for the development of effective therapeutic strategies.

From periphery immunity to central domain through clinical interview as a new insight on schizophrenia

Identifying disease predictors through advanced statistical models enables the discovery of treatment targets for schizophrenia. In this study, a multifaceted clinical and laboratory analysis was conducted, incorporating magnetic resonance spectroscopy with immunology markers, psychiatric scores, and biochemical data, on a cohort of 45 patients diagnosed with schizophrenia and 51 healthy controls. The aim was to delineate predictive markers for diagnosing schizophrenia. A logistic regression model was used, as utilized to analyze the impact of multivariate variables on the prevalence of schizophrenia. Utilization of a stepwise algorithm yielded a final model, optimized using Akaike's information criterion and a logit link function, which incorporated eight predictors (White Blood Cells, Reactive Lymphocytes, Red Blood Cells, Glucose, Insulin, Beck Depression score, Brain Taurine, Creatine and Phosphocreatine concentration). No single factor can reliably differentiate between healthy patients and those with schizophrenia. Therefore, it is valuable to simultaneously consider the values of multiple factors and classify patients using a multivariate model.

TLR/mTOR inflammatory signaling pathway: novel insight for the treatment of schizophrenia

The Toll-like receptor (TLR)/mammalian target of rapamycin (mTOR) signaling pathway is involved in the intracellular regulation of protein synthesis, specifically the ones that mediate neuronal morphology and facilitate synaptic plasticity. The activity of TLR/mTOR signaling has been disrupted, leading to neurodevelopment and deficient synaptic plasticity, which are the main symptoms of schizophrenia. The TLR receptor activates the mTOR signaling pathway and increases the elevation of inflammatory cytokines. Interleukin (IL)-6 is the most commonly altered cytokine, while IL-1, tumor necrosis factor, and interferon (IFN) also lead to SCZ. Anti-inflammatory and anti-oxidative agents such as celecoxib, aspirin, minocycline, and omega-3 fatty acids have shown efficiency against SCZ. As a result, inhibition of the inflammatory process could be suggested for the treatment of SCZ. So mTOR/TLR blockers represent the treatment of SCZ due to their inflammatory consequences. The objective of the present work was to find a novel anti-inflammatory agent that may block the mTOR/TLR inflammatory signaling pathways and might pave the way for the treatment of neuroinflammatory SCZ. Data were collected from experimental and clinical studies published in English between 1998 and October 2022 from Google Scholar, PubMed, Scopus, and the Cochrane library.

Ancient dormant virus remnant ERVW-1 drives ferroptosis via degradation of GPX4 and SLC3A2 in schizophrenia

Human endogenous retroviruses (HERVs) are remnants of retroviral infections in human germline cells from millions of years ago. Among these, ERVW-1 (also known as HERV-W-ENV, ERVWE1, or ENVW) encodes the envelope protein of the HERV-W family, which contributes to the pathophysiology of schizophrenia. Additionally, neuropathological studies have revealed cell death and disruption of iron homeostasis in the brains of individuals with schizophrenia. Here, our bioinformatics analysis showed that differentially expressed genes in the human prefrontal cortex RNA microarray dataset (GSE53987) were mainly related to ferroptosis and its associated pathways. Clinical data demonstrated significantly lower expression levels of ferroptosis-related genes, particularly Glutathione peroxidase 4 (GPX4) and solute carrier family 3 member 2 (SLC3A2), in schizophrenia patients compared to normal controls. Further in-depth analyses revealed a significant negative correlation between ERVW-1 expression and the levels of GPX4/SLC3A2 in schizophrenia. Studies indicated that ERVW-1 increased iron levels, malondialdehyde (MDA), and transferrin receptor protein 1 (TFR1) expression while decreasing glutathione (GSH) levels and triggering the loss of mitochondrial membrane potential, suggesting that ERVW-1 can induce ferroptosis. Ongoing research has shown that ERVW-1 reduced the expression of GPX4 and SLC3A2 by inhibiting their promoter activities. Moreover, Ferrostatin-1 (Fer-1), the ferroptosis inhibitor, reversed the iron accumulation and mitochondrial membrane potential loss, as well as restored the expressions of ferroptosis markers GSH, MDA, and TFR1 induced by ERVW-1. In conclusion, ERVW-1 could promote ferroptosis by downregulating the expression of GPX4 and SLC3A2, revealing a novel mechanism by which ERVW-1 contributes to neuronal cell death in schizophrenia.

The role of insulin/IGF1 signalling in neurodevelopmental and neuropsychiatric disorders - Evidence from human neuronal cell models

Insulin and insulin-like growth factor 1 (IGF1) signalling play a central role in the development and maintenance of neurons in the brain, and human neurodevelopmental as well as neuropsychiatric disorders have been linked to impaired insulin and IGF1 signalling. This review focuses on the impairments of the insulin and IGF1 signalling cascade in the context of neurodevelopmental and neuropsychiatric disorders, based on evidence from human neuronal cell models. Clear evidence was obtained for impaired insulin and IGF1 receptor downstream signalling in neurodevelopmental disorders, while the evidence for its role in neuropsychiatric disorders was less substantial. Human neuronal model systems can greatly add to our knowledge about insulin/IGF1 signalling in the brain, its role in restoring dendritic maturity, and complement results from clinical studies and animal models. Moreover, they represent a useful model for the development of new therapeutic strategies. Further research is needed to systematically investigate the exact role of the insulin/IGF1 signalling cascades in neurodevelopmental and neuropsychiatric disorders, and to elucidate the respective therapeutic implications.

Retinal Neurodegeneration as a Potential Biomarker of Accelerated Aging in Schizophrenia Spectrum Disorders

BACKGROUND AND HYPOTHESES

Several biological markers are believed to reflect accelerated aging in schizophrenia spectrum disorders; however, retinal neural changes have not yet been explored as potential CNS biomarkers of accelerated aging in this population. The aim of this study was to determine whether retinal neural layer thinning is more strongly related to age in schizophrenia and schizoaffective disorder patients (SZ) than in a psychiatrically healthy control group (CON).

STUDY DESIGN

Schizophrenia (n = 60) and CON participants (n = 69) underwent spectral domain optical coherence tomography (OCT) scans to examine the following variables in both eyes: retinal nerve fiber layer (RNFL) thickness, macula central subfield (CSF) thickness, macula volume, ganglion cell layer-inner plexiform layer (GCL-IPL) thickness, optic cup volume, and cup-to-disc ratio. Eleven participants in each group had diabetes or hypertension.

STUDY RESULTS

Significant negative relationships between age and RNFL thickness, macula volume, and GCL-IPL thickness were observed in the SZ group, while no significant relationships were observed in the CON group. However, many of the findings in the SZ group lost significance when participants with diabetes/hypertension were removed from analyses. A notable exception to this was that the age × SZ interaction accounted for a unique proportion of variance in GCL-IPL thinning over and above the effect of diabetes/hypertension.

CONCLUSIONS

The results suggest that retinal atrophy occurs at an increased rate in schizophrenia spectrum disorders, potentially reflecting accelerated aging inherent to these conditions, with considerable contributions from systemic medical diseases closely linked to this population.

The Dysregulated MAD in Mad: A Neuro-theranostic Approach Through the Induction of Autophagic Biomarkers LC3B-II and ATG

The word mad has historically been associated with the psyche, emotions, and abnormal behavior. Dementia is a common symptom among psychiatric disorders or mad (schizophrenia, depression, bipolar disorder) patients. Autophagy/mitophagy is a protective mechanism used by cells to get rid of dysfunctional cellular organelles or mitochondria. Autophagosome/mitophagosome abundance in autophagy depends on microtubule-associated protein light chain 3B (LC3B-II) and autophagy-triggering gene (ATG) which functions as an autophagic biomarker for phagophore production and quick mRNA disintegration. Defects in either LC3B-II or the ATG lead to dysregulated mitophagy-and-autophagy-linked dementia (MAD). The impaired MAD is closely associated with schizophrenia, depression, and bipolar disorder. The pathomechanism of psychosis is not entirely known, which is the severe limitation of today's antipsychotic drugs. However, the reviewed circuit identifies new insights that may be especially helpful in targeting biomarkers of dementia. Neuro-theranostics can also be achieved by manufacturing either bioengineered bacterial and mammalian cells or nanocarriers (liposomes, polymers, and nanogels) loaded with both imaging and therapeutic materials. The nanocarriers must cross the BBB and should release both diagnostic agents and therapeutic agents in a controlled manner to prove their effectiveness against psychiatric disorders. In this review, we highlighted the potential of microRNAs (miRs) as neuro-theranostics in the treatment of dementia by targeting autophagic biomarkers LC3B-II and ATG. Focus was also placed on the potential for neuro-theranostic nanocells/nanocarriers to traverse the BBB and induce action against psychiatric disorders. The neuro-theranostic approach can provide targeted treatment for mental disorders by creating theranostic nanocarriers.

Exploring the key factors of schizophrenia relapse by integrating LC-MS/1H NMR metabolomics and weighted correlation network analysis

BACKGROUND

Lack of comprehending key factors of schizophrenia relapse has impeded its effective treatment, indicating that the mechanism clarification and available intervention of schizophrenia relapse required further amelioration.

METHOD

Based on the integration of LC-MS and ¹H NMR metabolomics, a weighted correlation network was established to screen pivotal factors of accelerating schizophrenia relapse. Then, the cluster most correlated with schizophrenia relapse was explored, and the biological function of cluster was investigated. Next, the key biomarker related to schizophrenia relapse was obtained through multiple algorithms. Moreover, the Lilikoi algorithm and correlation analysis were implemented to reveal the association between key biomarker and schizophrenia relapse.

RESULT

Results showed that 458 different forms of metabolites were identified for structuring the weighted correlation network. The module-trait correlation indicated that the turquoise module was the most highly correlated with schizophrenia relapse. Further, network analysis revealed that, in turquoise module, cluster 1 composed of 139 metabolites (involved in lipid metabolism and energy metabolism) was the most important subnetwork relevant to schizophrenia relapse. Finally, phenylalanylphenylalanine was recommended as the key biomarker related to schizophrenia relapse. Moreover, the correlation analysis indicated that phenylalanylphenylalanine might affect the progression of schizophrenia by intervening in energy metabolism.

CONCLUSION

In summary, critical factors of schizophrenia relapse have been revealed in our research, expounding the schizophrenia progression more systemically, which could shed some light on improving the intervention of schizophrenia relapse.

Psychotic-like experiences are associated with physical disorders in general population: A cross-sectional study from the NESARC II

BACKGROUND

Psychotic-like experiences (PLEs) constitute subthreshold symptoms of psychotic disorders, and belong to five distinct dimensions: Positive, Negative, Depressive, Mania and Disorganization. PLEs are associated with various psychiatric disorders. However, few studies examined their association with physical disorders.

OBJECTIVE

Our aims were (1) to assess the associations between various physical disorders and PLEs in a U.S. representative sample, and (2) to examine these associations according to the five dimensions of PLEs.

METHOD

We used data from the wave II (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-II), a large national sample representative of the US population (N = 34,653). Participants were assessed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule 4. Twenty-two PLEs were examined. Lifetime prevalence and adjusted Odds-Ratio (aOR) reflecting the association of sixteen physical disorders (including notably metabolic conditions and heart diseases) with PLEs were calculated.

RESULTS

All studied physical disorders were associated with the presence of PLEs. Particularly the presence of any physical condition, any heart disease and diabetes were more frequent in participants with at least one PLE compared with the group without any PLE (aOR = 1.74, 95% CI = 1.62-1.87, aOR = 1.44, 95% CI = 1.33-1.55 and aOR = 1.38, 95% CI = 1.24-1.54, respectively). Almost all physical disorders were associated with the five dimensions of PLEs.

CONCLUSIONS

PLEs were associated with a large range of physical disorders, with a gradual dose effect. To assess PLEs in the general population could help with the screening of subjects with physical disorders.

Combined metabolic activators improve cognitive functions in Alzheimer's disease patients: a randomised, double-blinded, placebo-controlled phase-II trial

BACKGROUND

Alzheimer's disease (AD) is associated with metabolic abnormalities linked to critical elements of neurodegeneration. We recently administered combined metabolic activators (CMA) to the AD rat model and observed that CMA improves the AD-associated histological parameters in the animals. CMA promotes mitochondrial fatty acid uptake from the cytosol, facilitates fatty acid oxidation in the mitochondria, and alleviates oxidative stress.

METHODS

Here, we designed a randomised, double-blinded, placebo-controlled phase-II clinical trial and studied the effect of CMA administration on the global metabolism of AD patients. One-dose CMA included 12.35 g L-serine (61.75%), 1 g nicotinamide riboside (5%), 2.55 g N-acetyl-L-cysteine (12.75%), and 3.73 g L-carnitine tartrate (18.65%). AD patients received one dose of CMA or placebo daily during the first 28 days and twice daily between day 28 and day 84. The primary endpoint was the difference in the cognitive function and daily living activity scores between the placebo and the treatment arms. The secondary aim of this study was to evaluate the safety and tolerability of CMA. A comprehensive plasma metabolome and proteome analysis was also performed to evaluate the efficacy of the CMA in AD patients.

RESULTS

We showed a significant decrease of AD Assessment Scale-cognitive subscale (ADAS-Cog) score on day 84 vs day 0 (P = 0.00001, 29% improvement) in the CMA group. Moreover, there was a significant decline (P = 0.0073) in ADAS-Cog scores (improvement of cognitive functions) in the CMA compared to the placebo group in patients with higher ADAS-Cog scores. Improved cognitive functions in AD patients were supported by the relevant alterations in the hippocampal volumes and cortical thickness based on imaging analysis. Moreover, the plasma levels of proteins and metabolites associated with NAD + and glutathione metabolism were significantly improved after CMA treatment.

CONCLUSION

Our results indicate that treatment of AD patients with CMA can lead to enhanced cognitive functions and improved clinical parameters associated with phenomics, metabolomics, proteomics and imaging analysis. Trial registration ClinicalTrials.gov NCT04044131 Registered 17 July 2019, https://clinicaltrials.gov/ct2/show/NCT04044131.

Comparative Analysis of the Pre- and Post-Medication Effects of Antipsychotic Agents on the Blood-Based Oxidative Stress Biomarkers in Patients with Schizophrenia: A Meta-Analysis

OBJECTIVE

Studies have shown that oxidative stress (OS) is related to the pathophysiology of schizophrenia (SCZ), but whether antipsychotics can induce OS has not been investigated well. Moreover, antipsychotics have differential effects on the OS level modulation, i.e., different types of antipsychotics have different effects on the cellular antioxidants or pro-oxidants.

METHODS

We followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and investigated the OS indicators including both enzymatic and nonenzymatic markers, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), malondialdehyde (MDA), glutathione (GSH), vitamin C, etc., of SCZ patients at baseline and follow-up of mono-medication.

RESULTS

Twenty studies met the inclusion criteria, with a total of 1162 patients enrolled at baseline, and 1105 patients completed the follow-up. OS markers were changed after a period of antipsychotic treatment in SCZ patients. The GPx activity and MDA level decreased in the whole blood (P<0.05), also the serum MDA level decreased (P<0.05). For the first-episode SCZ patients, the activity of GPx and the level of MDA decreased, while the level of vitamin C increased (all P<0.05). The levels of MDA in patients receiving atypical antipsychotics decreased (P<0.05), while the level of GSH in patients with typical antipsychotics decreased (P=0.05).

CONCLUSION

Antipsychotic medication may cause changes in the levels of OS markers in different blood samples of SCZ patients. However, the available studies might not be sufficient to reveal the underlying facts accurately due to the poor quality of experimental designs in the published literature.

Mitochondrial dysfunction in psychiatric disorders

Psychiatric disorders are a heterogeneous group of mental disorders with abnormal mental or behavioral patterns, which severely distress or disable affected individuals and can have a grave socioeconomic burden. Growing evidence indicates that mitochondrial function plays an important role in developing psychiatric disorders. This review discusses the neuropsychiatric consequences of mitochondrial abnormalities in both animal models and patients. We also discuss recent studies associated with compromised mitochondrial function in various psychiatric disorders, such as schizophrenia (SCZ), major depressive disorder (MD), and bipolar disorders (BD). These studies employ various approaches including postmortem studies, imaging studies, genetic studies, and induced pluripotent stem cells (iPSCs) studies. We also summarize the evidence from animal models and clinical trials to support mitochondrial function as a potential therapeutic target to treat various psychiatric disorders. This review will contribute to furthering our understanding of the metabolic etiology of various psychiatric disorders, and help guide the development of optimal therapies.

Evaluation of mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1) gene in patients with schizophrenia

Background

Schizophrenia is a serious, complex mental disorder. The impairment of oxidative phosphorylation has a detrimental consequence on CNS function. Different ATP synthase subunits have been involved in the pathological process of various neurodegenerative disorders. Our goal was to evaluate the mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1, also named ATP5MC1) gene in patients with schizophrenia.

Methods

Determination of the expression levels of ATP5G1 in plasma and peripheral blood mononuclear cells (PBMCs) were performed by real-time PCR in 90 controls and 90 patients with schizophrenia.

Results

Patients had significantly decreased ATP5G1 mRNA expression levels in both plasma and PBMCs compared to controls. The receiver operating characteristic curve was applied to detect a cut-off value of ATP5G1 expression in plasma and PBMCs. The ATP5G1 relative expression in PBMCs had better performance with a cut-off value ≤ 21 (AUC = 0.892, P < 0.001), sensitivity of 94.44%, and specificity of 72.22% in discriminating between schizophrenic patients. ATP5G1 expression in PBMCs was an independent predictor in schizophrenia.

Conclusion

This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs. That might give insight into the role of ATP5G1 gene in the pathogenesis of schizophrenia.

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This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs, which was found as an independent risk factor.

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This might give insight into the role of the ATP5G1 gene in the pathogenesis of schizophrenia.

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Further studies are needed to evaluate the role of ATP5G1 in schizophrenia and their impact on ATP production in these patients.

Schizophrenia in Translation: Why the Eye?

Schizophrenia is increasingly recognized as a systemic disease, characterized by dysregulation in multiple physiological systems (eg, neural, cardiovascular, endocrine). Many of these changes are observed as early as the first psychotic episode, and in people at high risk for the disorder. Expanding the search for biomarkers of schizophrenia beyond genes, blood, and brain may allow for inexpensive, noninvasive, and objective markers of diagnosis, phenotype, treatment response, and prognosis. Several anatomic and physiologic aspects of the eye have shown promise as biomarkers of brain health in a range of neurological disorders, and of heart, kidney, endocrine, and other impairments in other medical conditions. In schizophrenia, thinning and volume loss in retinal neural layers have been observed, and are associated with illness progression, brain volume loss, and cognitive impairment. Retinal microvascular changes have also been observed. Abnormal pupil responses and corneal nerve disintegration are related to aspects of brain function and structure in schizophrenia. In addition, studying the eye can inform about emerging cardiovascular, neuroinflammatory, and metabolic diseases in people with early psychosis, and about the causes of several of the visual changes observed in the disorder. Application of the methods of oculomics, or eye-based biomarkers of non-ophthalmological pathology, to the treatment and study of schizophrenia has the potential to provide tools for patient monitoring and data-driven prediction, as well as for clarifying pathophysiology and course of illness. Given their demonstrated utility in neuropsychiatry, we recommend greater adoption of these tools for schizophrenia research and patient care.

Bioinformatics-based screening of key genes between maternal preeclampsia and offspring schizophrenia

Converging lines of evidence suggest an association between schizophrenia and prenatal neurodevelopmental disorders. Preeclampsia is a multisystem disease based on the coexistence of pregnancy and elevated blood pressure, which increases the risk for offspring abnormal neurodevelopment. Previous studies have showed maternal preeclampsia is associated with an increased risk of offspring schizophrenia, but the molecular mechanism remains unclear. In this study, we sought to identify key protein-coding genes between maternal preeclampsia and offspring schizophrenia. GSE53987 and GSE166846 datasets from Gene Expression Omnibus (GEO) database were analysed to obtain common differentially expressed genes (DEGs) between preeclampsia and schizophrenia. GSE62105 dataset was analysed to identify the DEGs' expressions in neural cells from one control and one schizophrenic patient. GSE92845 dataset was analysed to describe the changes of the DEGs in human neural stem cells. In total, we obtained ten common DEGs. All of them expressed differently in neural cells of the control and schizophrenic patient. We chose the six DEGs that had similar trend in both neural cells and UCB from preeclampsia patients and analysed their expressions in human neural stem cells over time. We found the expressions of CKAP5 and SAT1 in day 30 had significant difference comparing with those in day 0. The KEGG pathway analysis of their interaction proteins showed they were involved with metabolism. Our results may provide a new insight for genetic basis of relationship between maternal preeclampsia and offspring schizophrenia.

Glial Purinergic Signaling-Mediated Oxidative Stress (GPOS) in Neuropsychiatric Disorders

Oxidative stress (OS) has been implicated in the progression of multiple neuropsychiatric disorders, including schizophrenia (SZ), major depressive disorder (MDD), bipolar disorder, and autism. However, whether glial purinergic signaling interaction with oxidative/antioxidative system displays an important role in neuropsychiatric disorders is still unclear. In this review, we firstly summarize the oxidative/antioxidative pathways shared in different glial cells and highlight the cell type-specific difference in response to OS. Then, we collect the evidence showing the regulation of purinergic signaling in OS with an emphasis on adenosine and its receptors, P2Y1 receptor in the P2Y family and P2X7receptor in the P2X family. Available data shows that the activation of P1 receptors and P2X accelerates the OS; reversely, the activation of the P2Y family (P2Y1) causes protective effect against OS. Finally, we discuss current findings demonstrating the contribution of the purinergic signaling system to neuropsychiatric disorders and point out the potential role of OS in this process to propose a “glial purinergic-oxidative stress” (“GPOS”) hypothesis for future development of therapeutic strategies against a variety of neuropsychiatric disorders.

Macrophage migration inhibitory factor as a potential novel biomarker for cognitive function in patients with first-episode schizophrenia

OBJECTIVE

Cognitive impairment is prevalent in schizophrenia. Macrophage migration inhibitory factor which is released into the circulation under stress or inflammation, is associated with cognition and also plays an important role in immunity. However, no study has investigated the relationship between macrophage migration inhibitory factor and cognitive function in first-episode schizophrenia patients at baseline or after treatment. This study investigated the pre- and post-risperidone treatment correlations between serum macrophage migration inhibitory factor levels and cognitive function in first-episode schizophrenia patients.

METHODS

A total of 83 first-episode schizophrenia patients who received risperidone monotherapy and 57 healthy controls - matched for sex, age, smoking status, education (years), marital status and waist-to-hip ratio - were included. Macrophage migration inhibitory factor levels were measured before and 10 weeks after treatment in the patient group and at baseline in the controls. Pre- and post-treatment cognitive functions in patients were assessed using the MATRICS Consensus Cognitive Battery.

RESULTS

At baseline, macrophage migration inhibitory factor levels were significantly higher in first-episode schizophrenia patients than those in healthy controls (p < 0.01) and decreased in patients after 10 weeks of risperidone treatment compared with baseline (p < 0.05). The MATRICS Consensus Cognitive Battery total score and the sub-scores for the Trail Making Test, Symbol Coding, Letter Number Sequence, Maze and Brief Visuospatial Memory Test-Revised improved significantly after risperidone treatment. After controlling for age, sex, education, waist-to-hip ratio and smoking status, partial correlation analysis showed a positive correlation between baseline macrophage migration inhibitory factor levels and patients' baseline MATRICS Consensus Cognitive Battery verbal memory scores (r = 0.29, p = 0.01). Macrophage migration inhibitory factor changes correlated negatively with verbal memory changes (r = -0.26, p = 0.04). Multiple linear regression analysis identified a definite correlation between the changes in word memory test score and macrophage migration inhibitory factor level (β = -0.09, p = 0.04).

CONCLUSION

Macrophage migration inhibitory factor may be involved in the process of cognitive impairment in first-episode schizophrenia and repair mechanisms following risperidone treatment.

Aberrant cortical surface and cognition function in drug-naive first-episode schizophrenia

OBJECTIVE

Impaired cognitive function is a central symptom of schizophrenia and is often correlated with inferior global functional outcomes. However, the role of some neurobiological factors such as cortical structure alterations in the underlying cognitive damages in schizophrenia remains unclear. The present study attempted to explore the neurobiomarkers of cognitive function in drug-naive, first-episode schizophrenia by using structural magnetic resonance imaging (MRI).

METHODS

The present study was conducted in patients with drug-naive, first-episode schizophrenia (SZ) and healthy controls (HCs). MRI T1 images were pre-processed using CAT12. Surface-based morphometry (SBM) was utilised to evaluate structural parameters such as cortical thickness and sulcus depth. The positive and negative syndrome scale (PANSS) and Chinese version of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) consensus cognitive battery (MCCB) were employed to estimate the psychotic symptoms and cognition, respectively.

RESULTS

A total of 117 patients with drug-naive first-episode schizophrenia (SZ) and 98 healthy controls (HCs) were included. Both the cortical thickness and sulcus depth in the frontal lobe were lower in patients with SZ than in the HCs under family-wise error correction (p < 0.05). Attention and visual learning in MCCB were positively correlated with the right lateral orbitofrontal cortical thickness in the patients with SZ (p < 0.01).

CONCLUSIONS

The reduced surface value of multiple cortical structures, particularly the cortical thickness and sulcus depth in the frontal lobe, could be the potential biomarkers for cognitive impairment in SZ.

Overlapping Genetic Architecture Between Schizophrenia and Neurodegenerative Disorders

Epidemiological and clinical studies have suggested comorbidity between schizophrenia and several neurodegenerative disorders. However, little is known whether there exists shared genetic architecture. To explore their relationship from a genetic and transcriptomic perspective, we applied polygenic and linkage disequilibrium-informed methods to examine the genetic correlation between schizophrenia and amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s disease and frontotemporal dementia. We further combined genome-wide association summary statistics with large-scale transcriptomic datasets, to identify putative shared genes and explore related pathological tissues. We identified positive and significant correlation between schizophrenia and ALS at genetic (correlation 0.22; 95% CI: 0.16–0.28; p = 4.00E-04) and transcriptomic (correlation 0.08; 95% CI: 0.04–0.11; p = 0.034) levels. We further demonstrated that schizophrenia- and ALS-inferred gene expression overlap significantly in four tissues including skin, small intestine, brain cortex and lung, and highlighted three genes, namely GLB1L3, ZNHIT3 and TMEM194A as potential mediators of the correlation between schizophrenia and ALS. Our findings revealed overlapped gene expression profiles in specific tissues between schizophrenia and ALS, and identified novel potential shared genes. These results provided a better understanding for the pleiotropy of schizophrenia, and paved way for future studies to further elucidate the molecular drivers of schizophrenia.

Plasma metabolomics of schizophrenia with cognitive impairment: A pilot study

Schizophrenia (SCZ) acts as a complex and burdensome disease, in which the functional outcome can be validly predicted by cognitive impairment, as one of the core features. However, there still lack considerable markers of cognitive deficits in SCZ. Based on metabolomics, it is expected to identify different metabolic characteristics of SCZ with cognitive impairment. In the present study, 17 SCZ patients with cognitive impairment (CI), 17 matched SCZ patients with cognitive normal (CN), and 20 healthy control subjects (HC) were recruited, whose plasma metabolites were measured using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The result of metabolic profiling indicated the identification of 46 differentially expressed metabolites between HC, CN, and CI groups, with 7 differentially expressed metabolites between CN and CI groups. Four differential metabolites (imidazolepropionic acid, Homoserine, and Aspartic acid) were repeatedly found in both screenings, by which the formed biomarker panel could discriminate SCZ with cognitive impairment from matched patients (AUC = 0.974) and health control (AUC = 0.841), respectively. Several significant metabolic pathways were highlighted in pathway analysis, involving Alanine, aspartate and glutamate metabolism, D-glutamine and D-glutamate metabolism, and Citrate cycle (TCA cycle). In this study, several differentially expressed metabolites were identified in SCZ with cognitive impairment, providing novel insights into clinical treatment strategies.

Effect of Antipsychotic Treatment on Neutrophil-to-Lymphocyte Ratio during Hospitalization for Acute Psychosis in the Course of Schizophrenia-A Cross-Sectional Retrospective Study

Background: Studies have shown that there are deviations in the results of peripheral blood counts, which lead to increased values of the neutrophils-to-lymphocytes ratio (NLR) in schizophrenia. Antipsychotic drugs have proven to lower the levels of pro-inflammatory cytokines and a growing number of studies indicate a similar effect on NLR values. Methods: We identified inpatients with schizophrenia and collected data of NLR at the beginning (NLR₁) and end (NLR₂) of hospitalization, the status of antipsychotic medication on admission and potential confounding factors. In the statistical analysis, we applied a linear mixed model. Results: After the inclusion and exclusion process the records of 40 patients (n_p = 40) and 71 hospitalizations (n_h = 71) were analyzed. We found that in the group of antipsychotics-naive patients, the NLR₁ were significantly higher than the NLR₂ values. Such a difference did not occur in the case of non-antipsychotics-naïve patients. Age and the diagnosis of hypothyroidism influenced the value of change in NLR from the beginning to the end of hospitalization in a given patient (ΔNLR). Conclusions: The study confirmed the lowering effect of antipsychotics on NLR values in psychosis. The NLR may potentially be a tool for assessing response to treatment with antipsychotics.

Juvenile social isolation leads to schizophrenia-like behaviors via excess lactate production by astrocytes

Repeated early environmental deprivation is regarded as a typical paradigm to mimic the behavioral abnormalities and brain dysfunction that occur in psychiatric disorders. Previously, we reported that social isolation could disrupt prepulse inhibition (PPI) in Sprague-Dawley (SD) rats, producing the typical characteristics of a schizophrenia animal model. Based on further analysis of previous proteomic and transcriptomic data, a disrupted balance of glucose metabolism was found in the prefrontal cortex (PFC) of isolated rats. Subsequently, in the first experiment of this study, we investigated the effects of juvenile social isolation (postnatal days (PND) 21-34) on PPI and lactate levels in PND56 rats. Compared with the social rearing group, rats in the isolated rearing group showed disrupted PPI and increased lactate levels in the PFC. In the second experiment, at PND55, the model rats were acutely injected with a glycogen phosphorylase inhibitor (4-dideoxy-1,4-imino-darabinitol, DAB) or control saline in the bilateral PFC. Our data showed that acute DAB administration (50 pmol, 0.5 μl) significantly improved the disrupted PPI and decreased the levels of oxidative phosphorylation (OXPHOS)-related mRNAs as well as lactate. In summary, our results suggested that excess astrocytic lactate production was involved in the impairment of auditory sensory gating of isolated rats, which may contribute to the metabolic pathogenesis of schizophrenia.

An overview of the human brain myelin proteome and differences associated with schizophrenia

OBJECTIVES

Disturbances in the myelin sheath drive disruptions in neural transmission and brain connectivity as seen in schizophrenia. Here, the myelin proteome was characterised in schizophrenia patients and healthy controls to visualise differences in proteomic profiles.

METHODS

A liquid chromatography tandem mass spectrometry-based shotgun proteomic analysis was performed of a myelin-enriched fraction of postmortem brain samples from schizophrenia patients (n = 12) and mentally healthy controls (n = 8). In silico pathway analyses were performed on the resulting data.

RESULTS

The present characterisation of the human myelinome led to the identification of 480 non-redundant proteins, of which 102 proteins are newly annotated to be associated with the myelinome. Levels of 172 of these proteins were altered between schizophrenia patients and controls. These proteins were mainly associated with glial cell differentiation, metabolism/energy, synaptic vesicle function and neurodegeneration. The hub proteins with the highest degree of connectivity in the network included multiple kinases and synaptic vesicle transport proteins.

CONCLUSIONS

Together these findings suggest disruptive effects on synaptic activity and therefore neural transmission and connectivity, consistent with the dysconnectivity hypothesis of schizophrenia. Further studies on these proteins may lead to the identification of potential drug targets related to the synaptic dysconnectivity in schizophrenia and other psychiatric and neurodegenerative disorders.

Monitoring the Redox Status in Multiple Sclerosis

Worldwide, over 2.2 million people suffer from multiple sclerosis (MS), a multifactorial demyelinating disease of the central nervous system. MS is characterized by a wide range of motor, autonomic, and psychobehavioral symptoms, including depression, anxiety, and dementia. The blood, cerebrospinal fluid, and postmortem brain samples of MS patients provide evidence on the disturbance of reduction-oxidation (redox) homeostasis, such as the alterations of oxidative and antioxidative enzyme activities and the presence of degradation products. This review article discusses the components of redox homeostasis, including reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products. The reactive chemical species cover frequently discussed reactive oxygen/nitrogen species, infrequently featured reactive chemicals such as sulfur, carbonyl, halogen, selenium, and nucleophilic species that potentially act as reductive, as well as pro-oxidative stressors. The antioxidative enzyme systems cover the nuclear factor erythroid-2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling pathway. The NRF2 and other transcriptional factors potentially become a biomarker sensitive to the initial phase of oxidative stress. Altered components of the redox homeostasis in MS were discussed in search of a diagnostic, prognostic, predictive, and/or therapeutic biomarker. Finally, monitoring the battery of reactive chemical species, oxidative enzymes, antioxidative enzymes, and degradation products helps to evaluate the redox status of MS patients to expedite the building of personalized treatment plans for the sake of a better quality of life.

The Relationship between the Level of Anterior Cingulate Cortex Metabolites, Brain-Periphery Redox Imbalance, and the Clinical State of Patients with Schizophrenia and Personality Disorders

Schizophrenia is a complex mental disorder whose course varies with periods of deterioration and symptomatic improvement without diagnosis and treatment specific for the disease. So far, it has not been possible to clearly define what kinds of functional and structural changes are responsible for the onset or recurrence of acute psychotic decompensation in the course of schizophrenia, and to what extent personality disorders may precede the appearance of the appropriate symptoms. The work combines magnetic resonance spectroscopy imaging with clinical evaluation and laboratory tests to determine the likely pathway of schizophrenia development by identifying peripheral cerebral biomarkers compared to personality disorders. The relationship between the level of metabolites in the brain, the clinical status of patients according to International Statistical Classification of Diseases and Related Health Problems, 10th Revision ICD-10, duration of untreated psychosis (DUP), and biochemical indices related to redox balance (malondialdehyde), the efficiency of antioxidant systems (FRAP), and bioenergetic metabolism of mitochondria, were investigated. There was a reduction in the level of brain N-acetyl-aspartate and glutamate in the anterior cingulate gyrus of patients with schisophrenia compared to the other groups that seems more to reflect a biological etiopathological factor of psychosis. Decreased activity of brain metabolites correlated with increased peripheral oxidative stress (increased malondialdehyde MDA) associated with decreased efficiency of antioxidant systems (FRAP) and the breakdown of clinical symptoms in patients with schizophrenia in the course of psychotic decompensation compared to other groups. The period of untreated psychosis correlated negatively with glucose value in the brain of people with schizophrenia, and positively with choline level. The demonstrated differences between two psychiatric units, such as schizophrenia and personality disorders in relation to healthy people, may be used to improve the diagnosis and prognosis of schizophrenia compared to other heterogenous psychopathology in the future. The collapse of clinical symptoms of patients with schizophrenia in the course of psychotic decompensation may be associated with the occurrence of specific schizotypes, the determination of which is possible by determining common relationships between changes in metabolic activity of particular brain structures and peripheral parameters, which may be an important biological etiopathological factor of psychosis. Markers of peripheral redox imbalance associated with disturbed bioenergy metabolism in the brain may provide specific biological factors of psychosis however, they need to be confirmed in further studies.