Brain-derived neurotrophic factor (BDNF) levels in first-episode schizophrenia and healthy controls: A comparative study

Vortioxetine improved schizophrenia-like behavioral deficits in a Poly I:C-induced maternal immune activation model of schizophrenia in rats

BACKGROUND

Several studies provide clear evidence that exposure to various infections during pregnancy are linked with an increased risk for schizophrenia. In preclinical studies, administration of polyinosinic-polycytidylic acid (Poly I:C) in pregnant rodents can induce maternal immune activation leading to impairments in brain function in the offspring.

OBJECTIVES

The aim of this study was to investigate the effect of vortioxetine, a multimodal selective serotonin reuptake inhibitor (SSRI), in the pathophysiology of Poly I:C-induced schizophrenia-like model in rats.

METHODS

For this purpose, Poly I:C (8 mg/kg, ip) was injected into pregnant animals 14 days after mating, and tail blood was taken for determination of IL-6 levels after 2 h. At postnatal days 83-86, behavioral tests were performed.

RESULTS

Our results revealed that Poly I:C caused impairments in prepulse inhibition, novel object recognition, social interaction, and open-field tests. Chronic administration of vortioxetine (2.5, 5, and 10 mg/kg, ip, postnatal days 69-83) caused significant improvements in these deficits.

CONCLUSION

Overall, our findings indicate that vortioxetine may provide new therapeutic approaches for the treatment of schizophrenia. We think that increased serotonergic activity in frontal brain regions may provide the ameliorative effect of vortioxetine, especially on negative and cognitive symptoms. Therefore, it will be useful to determine the efficacy of vortioxetine with combined drugs with further studies.

Plasma biomarkers in adolescents with schizophrenia-spectrum disorder

AIM

Schizophrenia onset in the developmental age has a strong neurodevelopmental burden and is associated with a poorer prognosis. The approach to diagnosis is still based on symptomatic description without objective validation. In this study, we aimed to compare the peripheral blood levels of hypothesized biomarker proteins: brain-derived neurotrophic factor (BDNF), proBDNF, p75 neurotrophin receptor (p75NTR ) and S100B between early-onset schizophrenia-spectrum adolescents (n = 45) and healthy controls (n = 34).

METHODS

Clinical assessment of the participants encompassed symptomatic description with the use of structured interviews and executive function objective measurement. Plasma levels of BDNF protein were significantly lower in schizophrenia patients than in controls both at admission (p = .003) and 6-8 weeks follow-up (p = .007).

RESULTS

We observed significant correlations between BDNF, proBDNF and p75NTR levels and positive and negative symptoms scale (PANSS) scores, p75NTR and S100B levels and suicidal parameters, as well as a correlation of BDNF plasma level with the risky decision-making style in Iowa Gambling Task (IGT).

CONCLUSIONS

The results indicate a potential value of studied proteins as a biomarker in the diagnosis and monitoring of the disease's course.

Correlation study of brain-derived neurotrophic factor, EEG γ activity and cognitive function in first-episode schizophrenia

BACKGROUND

Schizophrenia is characterised by neurotrophic, neuroelectrophysiological and cognitive dysfunction. However, there exists a paucity of research examining the association between serum brain-derived neurotrophic factor (BDNF) concentration, resting electroencephalogram (EEG) gamma activity, and cognitive impairment in individuals diagnosed with schizophrenia.

METHODS

In this study, 87 first-episode schizophrenia patients and 75 healthy controls were assessed. Measurements were conducted to determine the levels of BDNF, resting EEG γ-activity at left and right frontal pole EEG electrodes respectively (FP1/FP2) leads, and cognitive function as assessed by the Measurement and Treatment Research to Improve Cognition in Schizophrenia MATRICS Consensus Cognitive Battery (MCCB). Comparisons were made between the patient group and the control group, revealing lower BDNF levels, lower T-scores for 7 MCCB cognitive items, and higher EEG γ-activity among patients when compared to controls.

RESULTS

According to the correlation analysis, there were significant associations observed in the patient group. BDNF levels were found to be correlated with EEG γ activity as well as T-scores of speed of processing (SoP), verbal learning (VeL), and reasoning problem-solving (RPS). Moreover, EEG γ activity showed an association with both the total score of the Positive and Negative Syndrome Scale (PANSS) and T-score of SoP. These findings suggest a potential relationship between BDNF levels, EEG γ activity, cognitive domains, and clinical symptoms in individuals with first-episode schizophrenia.

CONCLUSIONS

In conclusion, our findings demonstrate the coexistence of neurobiochemical and electrophysiological abnormalities alongside cognitive dysfunction during the early stages of schizophrenia. These findings provide valuable insights into the mechanism of cognitive impairment in schizophrenia. By highlighting the simultaneous occurrence of these factors, our study contributes to a better understanding of the complex nature of schizophrenia and emphasizes the importance of studying its cognitive aspects.

The role of integrin beta in schizophrenia: a preliminary exploration

Integrins are transmembrane heterodimeric (αβ) receptors that transduce mechanical signals between the extracellular milieu and the cell in a bidirectional manner. Extensive research has shown that the integrin beta (β) family is widely expressed in the brain and that they control various aspects of brain development and function. Schizophrenia is a relatively common neurological disorder of unknown etiology and has been found to be closely related to neurodevelopment and neurochemicals in neuropathological studies of schizophrenia. Here, we review literature from recent years that shows that schizophrenia involves multiple signaling pathways related to neuronal migration, axon guidance, cell adhesion, and actin cytoskeleton dynamics, and that dysregulation of these processes affects the normal function of neurons and synapses. In fact, alterations in integrin β structure, expression and signaling for neural circuits, cortex, and synapses are likely to be associated with schizophrenia. We explored several aspects of the possible association between integrin β and schizophrenia in an attempt to demonstrate the role of integrin β in schizophrenia, which may help to provide new insights into the study of the pathogenesis and treatment of schizophrenia.

Predicting the diagnosis of various mental disorders in a mixed cohort using blood-based multi-protein model: a machine learning approach

The lack of objective diagnostic methods for mental disorders challenges the reliability of diagnosis. The study aimed to develop an easily accessible and useable objective method for diagnosing major depressive disorder (MDD), schizophrenia (SZ), bipolar disorder (BPD), and panic disorder (PD) using serum multi-protein. Serum levels of brain-derived neurotrophic factor (BDNF), VGF (non-acronymic), bicaudal C homolog 1 (BICC1), C-reactive protein (CRP), and cortisol, which are generally recognized to be involved in different pathogenesis of various mental disorders, were measured in patients with MDD (n = 50), SZ (n = 50), BPD (n = 55), and PD along with 50 healthy controls (HC). Linear discriminant analysis (LDA) was employed to construct a multi-classification model to classify these mental disorders. Both leave-one-out cross-validation (LOOCV) and fivefold cross-validation were applied to validate the accuracy and stability of the LDA model. All five serum proteins were included in the LDA model, and it was found to display a high overall accuracy of 96.9% when classifying MDD, SZ, BPD, PD, and HC groups. Multi-classification accuracy of the LDA model for LOOCV and fivefold cross-validation (within-study replication) reached 96.9 and 96.5%, respectively, demonstrating the feasibility of the blood-based multi-protein LDA model for classifying common mental disorders in a mixed cohort. The results suggest that combining multiple proteins associated with different pathogeneses of mental disorders using LDA may be a novel and relatively objective method for classifying mental disorders. Clinicians should consider combining multiple serum proteins to diagnose mental disorders objectively.

Group I mGluRs positive allosteric modulators improved schizophrenia-related behavioral and molecular deficits in the Poly I:C rat model

RATIONALE

Maternal polyinosinic-polycytidylic acid (Poly I:C) exposure leads to an increase in various proinflammatory cytokines and causes schizophrenia-like symptoms in offspring. In recent years, group I metabotropic glutamate receptors (mGluRs) have emerged as a potential target in the pathophysiology of schizophrenia.

OBJECTIVES

The aim of our study was to investigate the behavioral and molecular changes by using the mGlu1 receptor positive allosteric modulator (PAM) agent RO 67-7476, and the negative allosteric modulator (NAM) agent JNJ 16259685 and the mGlu5 receptor PAM agent VU-29, and NAM agent fenobam in the Poly I:C-induced schizophrenia model in rats.

METHODS

Female Wistar albino rats were treated with Poly I:C on day 14 of gestation after mating. On the postnatal day (PND) 35, 56 and 84, behavioral tests were performed in the male offspring. On the PND84, brain tissue was collected and the level of proinflammatory cytokines was determined by ELISA method.

RESULTS

Poly I:C caused impairments in all behavioral tests and increased the levels of proinflammatory cytokines. While PAM agents caused significant improvements in prepulse inhibition (PPI), novel object recognition (NOR), spontaneous alternation and reference memory tests, they brought the levels of proinflammatory cytokines closer to the control group. NAM agents were ineffective on behavioral tests. It was observed that PAM agents significantly improved Poly I:C-induced disruption in behavioral and molecular analyses.

CONCLUSIONS

These results suggest that PAM agents, particularly the mGlu5 receptor VU-29, are also promising and could be a potential target in schizophrenia.

The month of walking alone and BDNF level differ between drug-naive first-episode schizophrenia patients and healthy controls

Introduction

Schizophrenia is a neurodevelopmental disorder, characterized by impairment in reasoning, affectivity, and social relationships. Previous studies have shown delayed motor development and Brain-Derived Neurotrophic Factor (BDNF) level change in individuals with schizophrenia. We researched the month of walking alone (MWA) and BDNF level between drug-naive first-episode schizophrenia patients (FEP) and healthy control (HC), as well as how they behave in neurocognitive function and severity of symptoms. Predictors of schizophrenia were further explored too.

Methods

We researched the MWA and BDNF levels between FEP and HCs in the Second Xiangya Hospital of Central South University from August 2017 to January 2020, as well as how they behave in neurocognitive function and the severity of symptoms. A binary logistic regression analysis was used to examine the risk factors affecting the onset and treatment outcome of schizophrenia.

Results

We find that FEP showed a walking delay and lower BDNF levels compared to HCs, which were associated with cognitive impairment and severity of symptoms. According to the difference and correlation analysis results, and combined with the appropriate application conditions for binary logistic regression, Wechsler Intelligence Scale Picture completion, Hopkins Verbal Learning Test-Revised, and Trail Making Test: part A were added to the binary logistic regression analysis to distinguish FEP and HCs.

Conclusion

Our study has shown delayed motor development and changes in BDNF levels in schizophrenia, extending insight into the early identification of patients with schizophrenia versus healthy populations.

Markers of Schizophrenia—A Critical Narrative Update

Schizophrenia is a long-term mental disease, associated with functional impairment. Therefore, it is important to make an accurate diagnosis and implement the proper treatment. Biomarkers may be a potential tool for these purposes. Regarding advances in biomarker studies in psychosis, the current symptom-based criteria seem to be no longer sufficient in clinical settings. This narrative review describes biomarkers of psychosis focusing on the biochemical (peripheral and central), neurophysiological, neuropsychological and neuroimaging findings as well as the multimodal approach related with them. Endophenotype markers (especially neuropsychological and occulomotor disturbances) can be currently used in a clinical settings, whereas neuroimaging glutamate/glutamine and D2/D3 receptor density changes, as well as immunological Th2 and PRL levels, seem to be potential biomarkers that need further accuracy tests. When searching for biochemical/immunological markers in the diagnosis of psychosis, the appropriate time of body fluid collection needs to be considered to minimize the influence of the stress axis on their concentrations. In schizophrenia diagnostics, a multimodal approach seems to be highly recommended.

Serum BDNF levels, glycolipid metabolism in deficit schizophrenia: A case-control study

BACKGROUND

Few studies have compared serum BDNF and glycolipid profiles in patients with deficit schizophrenia (DS) and non-deficit schizophrenia (NDS). We aimed to compare BDNF and glycolipid profiles between DS and NDS patients and healthy controls, and to investigate the relationship between BDNF, glycolipid profiles in DS and NDS patients.

METHODS

A total of 591 patients with chronic schizophrenia (SZ) and 238 healthy controls participated in this study. According to Proxy for the Deficit Syndrome Scale, SZ patients were divided into DS (n = 158) and NDS (n = 273) patients. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). Serum BDNF levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

BDNF levels were significantly lower in SZ patients than those in healthy controls (7.81 ± 2.98 ng/ml vs. 11.96 ± 2.29 ng/ml, P < 0.01). Furthermore, BDNF levels were lower in DS group than those in NDS group (P = 0.007, OR = 0.846, 95% CI = 0.750-0.955). Lower triglyceride levels were also an independent predictor for DS patients (P = 0.007, OR = 0.846, 95% CI = 0.750-0.955). Serum BDNF levels were negatively associated with the severity of deficit syndrome in SZ patients (β = -1.151, t = -2.559, P = 0.011). In DS group, triglycerides were associated with PANSS negative subscore (β = -0.262, t = -2.994, P = 0.003) and depressive factor subscore (β = 0.282, t = 2.146, P = 0.035).

CONCLUSION

Serum BDNF and triglycerides may be informative biomarkers of DS in SZ patients. The differences in glycolipid metabolism patterns between DS and NDS patients indicate that deficit syndrome is an independent endophenotype of SZ patients.

Association Between Depressive Symptoms and Serum Brain-Derived Neurotrophic Factor Levels in Patients With First-Episode and Drug-Naïve Schizophrenia

Previous studies have revealed that brain-derived neurotrophic factor (BDNF) levels are inversely associated with the severity of depressive symptoms. In addition, serum BDNF levels tend to increase with improvement in depressive symptoms. There is also evidence that BDNF has a possible role in the pathophysiology of schizophrenia. Therefore, the purpose of this study was to determine whether BDNF levels correlated with depressive symptoms in patients with first-episode and drug-naïve (FEDN) schizophrenia. In this study, 90 patients with FEDN schizophrenia and 60 healthy controls were recruited. The Positive and Negative Syndrome Scale (PANSS) and the 17-item Hamilton Depression Scale (HAMD-17) were used to gage psychopathological and depressive symptoms, respectively. All participants had their BDNF levels measured using a sandwich enzyme-linked immunosorbent test. Serum BDNF levels were lower in patients with FEDN schizophrenia compared with healthy controls. Moreover, patients with depressive symptoms exhibited a higher PANSS total score and a higher general psychopathology score than those without depressive symptoms (p < 0.05). For patients with depressive symptoms, serum BDNF levels were higher than in those without depressive symptoms (p < 0.05). An association between BDNF levels and the positive subscore was also observed (p < 0.01). However, there was no significant association between BDNF levels and HAMD scores (p > 0.05). In conclusion, BDNF levels were shown to be higher in the serum of patients with FEDN schizophrenia with depressive symptoms than in those without. Additionally, low levels of serum BDNF may contribute to the positive symptoms of FEDN schizophrenia but not to depressive symptoms.

Aberrant expression of BDNF might serve as a candidate target for cocaine-induced psychosis: insights from bioinformatics analysis and microarray validation

Background

Cocaine use disorder (CUD) and associated psychosis are major public health issues worldwide, along with high relapse outcome and limited treatment options. Exploring the molecular mechanisms underlying cocaine-induced psychosis (CIP) could supply integrated insights for understanding the pathogenic mechanism and potential novel therapeutic targets.

Aims

The aim of the study was to explore common alterations of CUD-schizophrenia-target genes and identify core risk genes contributing to CIP through data mining and network pharmacology approach.

Methods

Target genes of CUD were obtained from GeneCards, Comparative Toxicogenomics Database, Swiss Target Prediction platform and PubChem. Schizophrenia-related target genes were derived from DisGeNET, GeneCards, MalaCards and Online Mendelian Inheritance in Man databases. Then, the overlap genes of these two sets were regarded as risk genes contributing to CIP. Based on these CUD-schizophrenia-target genes, functional annotation and pathway analysis were performed using the clusterProfiler package in R. Protein–protein interaction network construction and module detection were performed based on the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. Gene expression datasets GSE54839 and GSE93577 were applied for data validation and diagnostic capacity evaluation of interested hub genes.

Results

A total of 165 CUD-schizophrenia-target genes were obtained. These genes were mainly contributing to chemical synaptic transmission, neuropeptide hormone activity, postsynaptic membrane and neuroactive ligand–receptor interaction pathway. Network analysis and validation analysis indicated that BDNF might serve as an important risk gene in mediating CIP.

Conclusions

This study generates a holistic view of CIP and provides a basis for the identification of potential CUD-schizophrenia-target genes involved in the development of CIP. The abnormal expression of BDNF would be a candidate therapeutic target underlying the pathogenesis of CUD and associated CIP.

Plasma BDNF concentrations and the antidepressant effects of six ketamine infusions in unipolar and bipolar depression

Objectives

Accumulating evidence has implicated that brain derived neurotrophic factor (BDNF) is thought to be involved in the pathophysiology of depression, but its correlation with ketamine's antidepressant efficacy focusing on Chinese individuals with depression is not known. This study was aim to determine the correlation of plasma BDNF (pBDNF) concentrations and ketamine's antidepressant efficacy.

Methods

Ninety-four individuals with depression received six intravenous infusions ketamine (0.5 mg/kg). Remission and response were defined as Montgomery-Asberg Depression Rating Scale (MADRS) scores less than 10 and a reduction of 50% or more in MADRS scores, respectively. Plasma was collected at baseline and at 24 h and 2 weeks after completing six ketamine infusions (baseline, 13 d and 26 d).

Results

A significant improvement in MADRS scores and pBDNF concentrations was found after completing six ketamine infusions compared to baseline (all ps < 0.05). Higher baseline pBDNF concentrations were found in ketamine responders/remitters (11.0 ± 6.2/10.1 ± 5.8 ng/ml) than nonresponders/nonremitters (8.0 ± 5.5/9.2 ± 6.4 ng/ml) (all ps < 0.05). Baseline pBDNF concentrations were correlated with MADRS scores at 13 d (t =  - 2.011, p = 0.047) or 26 d (t =  - 2.398, p = 0.019) in depressed patients (all ps < 0.05). Subgroup analyses found similar results in individuals suffering from treatment refractory depression.

Conclusion

This preliminary study suggests that baseline pBDNF concentrations appeared to be correlated with ketamine's antidepressant efficacy in Chinese patients with depression.

Non-Syndromic Intellectual Disability and Its Pathways: A Long Noncoding RNA Perspective

Non-syndromic intellectual disability (NS-ID or idiopathic) is a complex neurodevelopmental disorder that represents a global health issue. Although many efforts have been made to characterize it and distinguish it from syndromic intellectual disability (S-ID), the highly heterogeneous aspect of this disorder makes it difficult to understand its etiology. Long noncoding RNAs (lncRNAs) comprise a large group of transcripts that can act through various mechanisms and be involved in important neurodevelopmental processes. In this sense, comprehending the roles they play in this intricate context is a valuable way of getting new insights about how NS-ID can arise and develop. In this review, we attempt to bring together knowledge available in the literature about lncRNAs involved with molecular and cellular pathways already described in intellectual disability and neural function, to better understand their relevance in NS-ID and the regulatory complexity of this disorder.