Vascular endothelial growth factor in major depressive disorder, schizophrenia, and bipolar disorder: A network meta-analysis

Toxoplasma gondii, endothelial cells and schizophrenia: is it just a barrier matter?

Toxoplasma gondii is an obligatory intracellular parasite responsible for causing toxoplasmosis. It is estimated that approximately one-third of the world's population has positive serology for toxoplasmosis. Acute T. gondii infection often results in subtle symptoms because of its nonspecific nature. Owing to immune pressure, parasites tend to encyst and persist in different tissues and organs, such as the brain, chronicling the infection. While most chronically infected individuals do not develop significant symptoms, the parasite can affect the central nervous system (CNS), leading to symptoms that range from dizziness to behavioral changes. To reach the CNS, parasites must overcome the blood-brain barrier, which is composed primarily of endothelial cells. While these cells are typically efficient at separating blood elements from the CNS, in T. gondii infection, they not only permit parasitic colonization of the CNS but also contribute to an inflammatory profile that may exacerbate previously established conditions at both the local CNS and systemic levels. An increasing body of research has demonstrated a potential link between the CNS, infection by T. gondii and the cellular or humoral response to infection, with the worsening of psychiatric conditions, such as schizophrenia. Therefore, continually advancing research aimed at understanding and mitigating the relationship between parasitic infection and schizophrenia is imperative.

ACSL3 is a promising therapeutic target for alleviating anxiety and depression in Alzheimer's disease

Alzheimer's disease (AD), the leading cause of dementia, affects over 55 million people worldwide and is often accompanied by depression and anxiety. Both significantly impact patients' quality of life and impose substantial societal and economic burdens on healthcare systems. Identifying the complex regulatory mechanisms that contribute to the psychological and emotional deficits in AD will provide promising therapeutic targets. Biosynthesis of omega-3 (ω3) and omega-6 fatty acids (ω6-FA) through long-chain acyl-CoA synthetases (ACSL) is crucial for cell function and survival. This is due to ω3/6-FA's imperative role in modulating the plasma membrane, energy production, and inflammation. While ACSL dysfunction is known to cause heart, liver, and kidney diseases, the role of ACSL in pathological conditions in the central nervous system (e.g., depression and anxiety) remains largely unexplored. The impact of ACSLs on AD-related depression and anxiety was investigated in a mouse model of Alzheimer's disease (3xTg-AD). ACSL3 levels were significantly reduced in the hippocampus of aged 3xTg-AD mice (via capillary-based immunoassay). This reduction in ACAL3 was closely associated with increased depression and anxiety-like behavior (via forced swim, tail suspension, elevated plus maze, and sucrose preference test). Upregulation of ACSL3 via adenovirus in aged 3xTg-AD mice led to increased protein levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor C (VEGF-C) (via brain histology, capillary-based immunoassay), resulting in alleviation of depression and anxiety symptoms. The present study highlights a novel neuroprotective role of ACSL3 in the brain. Targeting ACSL3 will offer an innovative approach for treating AD-related depression and anxiety.

In vivo evidence of increased vascular endothelial growth factor in patients with major depressive disorder

BACKGROUND

Vascular endothelial growth factor (VEGF) is a candidate mediator of blood-brain barrier (BBB) disruption in depression. However, previous studies have mainly focused on peripheral blood VEGF levels, and the results are heterogeneous. Here we use astrocyte-derived extracellular vesicles (ADEVs) isolated from plasma to explore the in vivo changes of VEGF levels in patients with major depressive disorder (MDD).

METHODS

Thirty-five unmedicated patients with MDD and 35 healthy controls (HCs) were enrolled, and plasma ADEVs were isolated from each participant. VEGF levels in ADEVs and glial fibrillary acidic protein (GFAP) in plasma were measured. Additionally, Alix and CD81, two established extracellular vesicle markers, were quantified in ADEVs.

RESULTS

At baseline, MDD patients exhibited significantly increased levels of VEGF in ADEVs and GFAP in plasma. Following four weeks of selective serotonin reuptake inhibitor treatment, these target protein levels did not significantly change. ROC curve analysis revealed an AUC of 0.711 for VEGF in ADEVs. In exploratory analysis, VEGF levels in ADEVs were positively correlated with Alix and CD81.

LIMITATIONS

Multiple factors regulate BBB permeability. This study focused solely on VEGF and the sample size for longitudinal analysis was relatively small.

CONCLUSION

Our study is the first to confirm increased ADEV-derived VEGF levels in patients with MDD, thereby providing preliminary evidence supporting the hypothesis that the BBB is disrupted in depression.

VEGF, IGF-1 and FGF-2 Serum Levels in Children and Adolescents with Autism Spectrum Disorder with and without Bipolar Disorder

PURPOSE

To investigate serum levels of VEGF, IGF-1 and FGF-2, and relationships with several clinical characteristics in children and adolescents with autism spectrum disorder (ASD) with and without bipolar disorder (BD).

METHOD

40 subjects with ASD + BD as study group, and 40 subjects with ASD as control group were included. Serum levels of VEGF, IGF-1, and FGF-2 were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

The study group was significantly higher than the control group in terms of ASD severity, self-harming behavior and sleep disturbance. Serum VEGF and FGF-2 levels were significantly higher in the ASD + BD group than in the control group. There was no significant difference in serum IGF-1 levels between the two groups. There was no correlation between VEGF, IGF-1 and FGF-2 serum levels and ASD severity in the study group. However there was a negative correlation between VEGF levels and age at first diagnosis of BD, and a positive correlation between IGF-1 levels and the number of bipolar episodes in the study group.

CONCLUSION

Growth factors like VEGF and FGF-2 may be potential biomarkers of bipolar disorder in young subjects with ASD. Given the difficulty of clinical management of BD in young subjects with ASD, potential biomarkers would help clinicians in the diagnosis and follow up of BD in this special population. Further research is needed whether VEGF and FGF-2 can be potential biomarkers in the clinical management of young subjects with ASD and BD.

Decreased serum VEGF and NRG1β1 levels in male patients with chronic schizophrenia: VEGF correlation with clinical symptoms and cognitive deficits

BACKGROUND

Vascular endothelial growth factor (VEGF) and neuregulin1 (NRG1) are multifunctional trophic factors reported to be dysregulated in schizophrenia. However, the relationships between serum concentrations and schizophrenia symptoms have differed markedly across studies, possibly because schizophrenia is a highly heterogenous disorder. The aim of this study was to investigate the associations of serum VEGF and NRG1 with clinical symptoms and cognitive deficits specifically in male patients with chronic schizophrenia.

METHODS

The study included 79 male patients with chronic schizophrenia and 79 matched healthy individuals. Serum VEGF, NRG1β1, S100B, S100A8, and neuropilin1 were measured using the Luminex liquid suspension chip detection method, psychopathological symptom severity using the Positive and Negative Symptom Scale (PANSS), and cognitive dysfunction using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

RESULTS

Serum VEGF and NRG1β1 concentrations were significantly lower in male chronic schizophrenic patients than healthy controls (P < 0.05), while serum S100B, S100A8, and neuropilin1 concentrations did not differ between groups (P > 0.05). Serum VEGF concentration was negatively correlated with PANSS negative subscore (beta = -0.220, t = -2.07, P = 0.042), general psychopathology subscore (beta = -0.269, t = -2.55, P = 0.013), and total score (beta = -0.234, t = -2.12, P = 0.038), and positively correlated with RBANS language score (beta = 0.218, t = 2.03, P = 0.045). Alternatively, serum NRG1β1 concentration was not correlated with clinical symptoms or cognitive deficits (all P > 0.05).

CONCLUSION

Dysregulation of VEGF and NRG1β1 signaling may contribute to the pathogenesis of chronic schizophrenia in males. Moreover, abnormal VEGF signaling may contribute directly or through intermediary processes to neuropsychiatric and cognitive symptom expression.

Exploration on the potential efficacy and mechanism of methyl salicylate glycosides in the treatment of schizophrenia based on bioinformatics, molecular docking and dynamics simulation

The etiological and therapeutic complexities of schizophrenia (SCZ) persist, prompting exploration of anti-inflammatory therapy as a potential treatment approach. Methyl salicylate glycosides (MSGs), possessing a structural parent nucleus akin to aspirin, are being investigated for their therapeutic potential in schizophrenia. Utilizing bioinformation mining, network pharmacology, molecular docking and dynamics simulation, the potential value and mechanism of MSGs (including MSTG-A, MSTG-B, and Gaultherin) in the treatment of SCZ, as well as the underlying pathogenesis of the disorder, were examined. 581 differentially expressed genes related to SCZ were identified in patients and healthy individuals, with 349 up-regulated genes and 232 down-regulated genes. 29 core targets were characterized by protein-protein interaction (PPI) network, with the top 10 core targets being BDNF, VEGFA, PVALB, KCNA1, GRIN2A, ATP2B2, KCNA2, APOE, PPARGC1A and SCN1A. The pathogenesis of SCZ primarily involves cAMP signaling, neurodegenerative diseases and other pathways, as well as regulation of ion transmembrane transport. Molecular docking analysis revealed that the three candidates exhibited binding activity with certain targets with binding affinities ranging from -4.7 to -109.2 kcal/mol. MSTG-A, MSTG-B and Gaultherin show promise for use in the treatment of SCZ, potentially through their ability to modulate the expression of multiple genes involved in synaptic structure and function, ion transport, energy metabolism. Molecular dynamics simulation revealed good binding abilities between MSTG-A, MSTG-B, Gaultherin and ATP2B2. It suggests new avenues for further investigation in this area.

Non-canonical pathways in the pathophysiology and therapeutics of bipolar disorder

Bipolar disorder (BD) is characterized by extreme mood swings ranging from manic/hypomanic to depressive episodes. The severity, duration, and frequency of these episodes can vary widely between individuals, significantly impacting quality of life. Individuals with BD spend almost half their lives experiencing mood symptoms, especially depression, as well as associated clinical dimensions such as anhedonia, fatigue, suicidality, anxiety, and neurovegetative symptoms. Persistent mood symptoms have been associated with premature mortality, accelerated aging, and elevated prevalence of treatment-resistant depression. Recent efforts have expanded our understanding of the neurobiology of BD and the downstream targets that may help track clinical outcomes and drug development. However, as a polygenic disorder, the neurobiology of BD is complex and involves biological changes in several organelles and downstream targets (pre-, post-, and extra-synaptic), including mitochondrial dysfunction, oxidative stress, altered monoaminergic and glutamatergic systems, lower neurotrophic factor levels, and changes in immune-inflammatory systems. The field has thus moved toward identifying more precise neurobiological targets that, in turn, may help develop personalized approaches and more reliable biomarkers for treatment prediction. Diverse pharmacological and non-pharmacological approaches targeting neurobiological pathways other than neurotransmission have also been tested in mood disorders. This article reviews different neurobiological targets and pathophysiological findings in non-canonical pathways in BD that may offer opportunities to support drug development and identify new, clinically relevant biological mechanisms. These include: neuroinflammation; mitochondrial function; calcium channels; oxidative stress; the glycogen synthase kinase-3 (GSK3) pathway; protein kinase C (PKC); brain-derived neurotrophic factor (BDNF); histone deacetylase (HDAC); and the purinergic signaling pathway.

Vascular Endothelial Growth Factor Polymorphism rs699947 Is Associated with Neurostructural Phenotypes in Youth with Bipolar Disorder

Background: Vascular endothelial growth factor (VEGF) may be relevant to bipolar disorder (BD) and brain structure. We evaluated VEGF rs699947 single-nucleotide polymorphism in relation to structural neuroimaging phenotypes in youth BD. Methods: We collected 3 T anatomical magnetic resonance images from 154 youth (79 BD and 75 healthy control [HC]) genotyped for VEGF rs699947. The participants were age (BD = 17.28 ± 1.40 and HC = 17.01 ± 1.83, t = -1.02, p = 0.31) and sex (BD = 63.3% females and HC = 52.0% females, χ2 = 2.01, p = 0.16) matched. Cortical thickness, surface area (SA), and volume were examined by region-of-interest (ROI) and vertex-wise analyses using general linear models (GLMs). ROI investigations selected for the prefrontal cortex (PFC), amygdala, and hippocampus. Vertex-wise analyses controlled for age, sex, and intracranial volume. Results: ROI results found lower PFC SA (p = 0.003, ηp2 = 0.06) and volume (p = 0.04, ηp2 = 0.03) in BD and a main effect of rs699947 on hippocampal volume (p = 0.03, ηp2 = 0.05). The latter two findings did not survive multiple comparisons. Vertex-wise analyses found rs699947 main effects on left postcentral gyrus volume (p < 0.001), right rostral anterior cingulate SA (p = 0.004), and right superior temporal gyrus thickness (p = 0.004). There were significant diagnosis-by-genotype interactions in the left superior temporal, left caudal middle frontal, left superior frontal, right fusiform, and right lingual gyri, and the left insular cortex. Posthoc analyses revealed the AA allele was associated with larger brain structures among HC, but smaller brain structures in BD for most clusters. Conclusions: Overall, we found preliminary evidence of divergent associations between BD and HC youth in terms of neurostructural correlates of VEGF rs699947 encompassing highly relevant frontotemporal regions.

Serum Levels of Tumor Necrosis Factor-α and Vascular Endothelial Growth Factor in the Subtypes of Clinical High Risk Individuals: A Prospective Cohort Study

Introduction

Numerous studies have established the roles of inflammation and angioneurins in the pathogenesis of schizophrenia (SCZ). This study aimed to compare the serum levels of tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF) in patients at clinical high risk (CHR) for psychosis or SCZ at baseline and one year after treatment.

Methods

A total of 289 CHR participants from the Shanghai At Risk for Psychosis Extended Program (SHARP) were tracked for a year. They were divided into two and four subtypes based on symptom severity according to the Structured Interview for Prodromal Syndromes (SIPS) and received standard medical care. At baseline and one-year follow-up, TNF-α and VEGF were detected using enzyme-linked immunosorbent assay, and pathological features were assessed using the Global Assessment of Function (GAF) score.

Results

Baseline TNF-α levels did not differ significantly, while VEGF levels were lower in patients with more severe symptoms. VEGF showed a negative correlation with negative features, both overall (r = -0.212, p = 0.010) and in the subgroup with higher positive scores (r = -0.370, p = 0.005). TNF-α was positively correlated with negative symptoms in the subgroup with higher negative scores (r = 0.352, p = 0.002). A three-way multivariate analysis of variance demonstrated that participants in Subtype 1 of positive or negative symptoms performed better than those in Subtype 2, with significant main effects and interactions of group and both cytokines.

Discussion

TNF-α and VEGF levels are higher and lower, respectively, in CHR patients with more severe clinical symptoms, particularly negative symptoms, which point to a worsening inflammatory and vascular status in the brain.

Clinical Improvement in Depression and Cognitive Deficit Following Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a long-standing treatment choice for disorders such as depression when pharmacological treatments have failed. However, a major drawback of ECT is its cognitive side effects. While numerous studies have investigated the therapeutic effects of ECT and its mechanism, much less research has been conducted regarding the mechanism behind the cognitive side effects of ECT. As both clinical remission and cognitive deficits occur after ECT, it is possible that both may share a common mechanism. This review highlights studies related to ECT as well as those investigating the mechanism of its outcomes. The process underlying these effects may lie within BDNF and NMDA signaling. Edema in the astrocytes may also be responsible for the adverse cognitive effects and is mediated by metabotropic glutamate receptor 5 and the protein Homer1a.

The Impact of Psoriasis and Atopic Dermatitis on Quality of Life: A Literature Research on Biomarkers

Psoriasis (PSO) and Atopic dermatitis (AD) are common inflammatory skin diseases that affect people of all ages globally. They negatively impact the quality of life (QoL) of patients in health-related aspects such as physical, psychological and mental functioning. Here, we conducted a review of studies relating to candidate biomarkers and indicators associated with QoL impairment in PSO and AD. Data research was performed using PUBMED and SCOPUS databases from inception to September 2022. Most of the included studies reported genomic or proteomic biomarkers associated with disease activity and QoL outcomes. Sociodemographic, clinical and therapeutic factors have also been implicated in deterioration of life quality in these patients. The inclusion of clinical characteristics, QoL impairment and co-diagnosis should be considered in drug development programs, since processing biomarkers based on an increased number of features in addition to drug class and disease will intensify the value of the biomarker itself, thereby maximizing the future clinical utility as a stratification tool.

Association between vascular endothelial growth factor-mediated blood-brain barrier dysfunction and stress-induced depression

Several lines of evidence suggest that stress induces the neurovascular dysfunction associated with increased blood-brain barrier (BBB) permeability, which could be an important pathology linking stress and psychiatric disorders, including major depressive disorder (MDD). However, the detailed mechanism resulting in BBB dysfunction associated in the pathophysiology of MDD still remains unclear. Herein, we demonstrate the role of vascular endothelial growth factor (VEGF), a key mediator of vascular angiogenesis and BBB permeability, in stress-induced BBB dysfunction and depressive-like behavior development. We implemented an animal model of depression, chronic restraint stress (RS) in BALB/c mice, and found that the BBB permeability was significantly increased in chronically stressed mice. Immunohistochemical and electron microscopic observations revealed that increased BBB permeability was associated with both paracellular and transcellular barrier alterations in the brain endothelial cells. Pharmacological inhibition of VEGF receptor 2 (VEGFR2) using a specific monoclonal antibody (DC101) prevented chronic RS-induced BBB permeability and anhedonic behavior. Considered together, these results indicate that VEGF/VEGFR2 plays a crucial role in the pathogenesis of depression by increasing the BBB permeability, and suggest that VEGFR2 inhibition could be a potential therapeutic strategy for the MDD subtype associated with BBB dysfunction.

Neurotrophin Crosstalk in the Etiology and Treatment of Neuropsychiatric and Neurodegenerative Disease

This article reviews the current progress in our understanding of the mechanisms by which growth factors, including brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), and select neurotrophin-regulated gene products, such as VGF (non-acronymic) and VGF-derived neuropeptides, function in the central nervous system (CNS) to modulate neuropsychiatric and neurodegenerative disorders, with a discussion of the possible therapeutic applications of these growth factors to major depressive disorder (MDD) and Alzheimer’s disease (AD). BDNF and VEGF levels are generally decreased regionally in the brains of MDD subjects and in preclinical animal models of depression, changes that are associated with neuronal atrophy and reduced neurogenesis, and are reversed by conventional monoaminergic and novel ketamine-like antidepressants. Downstream of neurotrophins and their receptors, VGF was identified as a nerve growth factor (NGF)- and BDNF-inducible secreted protein and neuropeptide precursor that is produced and trafficked throughout the CNS, where its expression is greatly influenced by neuronal activity and exercise, and where several VGF-derived peptides modulate neuronal activity, function, proliferation, differentiation, and survival. Moreover, levels of VGF are reduced in the CSF of AD subjects, where it has been repetitively identified as a disease biomarker, and in the hippocampi of subjects with MDD, suggesting possible shared mechanisms by which reduced levels of VGF and other proteins that are similarly regulated by neurotrophin signaling pathways contribute to and potentially drive the pathogenesis and progression of co-morbid neuropsychiatric and neurodegenerative disorders, particularly MDD and AD, opening possible therapeutic windows.

Brain vasculature disturbance in schizophrenia

PURPOSE OF REVIEW

The vascular hypothesis of schizophrenia (SZ) postulates that brain endothelial dysfunction contributes to brain pathophysiology. This review discusses recent evidence for and against this hypothesis, including data related to blood-brain barrier (BBB), brain endothelium, and brain blood supply, to provide a critical weighed update.

RECENT FINDINGS

Different studies report a consistent proportion of SZ patients showing increased BBB permeability, reflected by higher levels of albumin in the cerebral spinal fluid. Of note, this was not a result of antipsychotic medication. The high inflammatory profile observed in some SZ patients is strongly associated with increased BBB permeability to circulating immune cells, and with more severe cognitive deficiencies. Also, sex was found to interact with BBB integrity and permeability in SZ. The strongest independent genetic association with SZ has been identified in FZD1, a hypoxia-response gene that is 600-fold higher expressed in early development endothelium as compared to adult brain endothelium. Regarding brain blood supply, there is evidence to suggest alterations in proper brain perfusion in SZ. Nonetheless, ex-vivo experiments suggested that widely used antipsychotics favor vasoconstriction; thus, alterations in cerebral perfusion might be related to the patients' medication.

SUMMARY

In some patients with SZ, a vulnerable brain endothelium may be interacting with environmental stressors, such as inflammation or hypoxia, converging into a more severe SZ symptomatology. Gene expression and performance of human brain endothelium could vary along with development and the establishment of the BBB; therefore, we encourage to investigate its possible contribution to SZ considering this dynamic context.

Change of Circulating Vascular Endothelial Growth Factor Level and Reduction of Anhedonia Are Associated in Patients With Major Depressive Disorder Treated With Repetitive Transcranial Magnetic Stimulation

AIM

Vascular endothelial growth factor (VEGF) has been implicated in mediating the effect of antidepressant therapies as it plays a significant role in the neurogenesis. Anhedonia, an endophenotype of major depressive disorder (MDD), is related to the dorsolateral prefrontal cortex, the major focus of brain stimulation in MDD. The aim of our study was to analyze the change of serum VEGF level after rTMS treatment in association with anhedonia.

MATERIALS AND METHODS

A dataset of 17 patients with TRD who were treated with antidepressants and bilateral rTMS for 2 × 5 days was analyzed. Depression was measured by the Montgomery-Asberg Depression Scale (MADRS) and anhedonia by the Snaith-Hamilton Pleasure Scale (SHAPS) for monitoring the symptom changes. The serum VEGF levels and symptoms were assessed on the first (V1), on the 14th (V2), and on the 28th day (V3). The level of VEGF was measured by ELISA assay.

RESULTS

There was no significant association between MADRS scores and serum VEGF levels at any timepoint. The decrease in the SHAPS score was significantly associated with the increase in VEGF level between V1 and V2 (p = 0.001). The VEGF levels were significantly higher in non-responders than in responders (p = 0.04). The baseline VEGF level has been proven as a significant predictor of treatment response (p = 0.045).

CONCLUSION

Our results suggest that serum VEGF can be sensitive to the changes of anhedonia during rTMS treatment. Considering that the most widely used depression scales are not applicable for the assessment of anhedonia, measurement of anhedonia in rTMS treatment studies of patients with TRD can be suggested as more appropriate data on distinct pathogenic pathways and specific biomarkers of the disorder.

Associations of Serum Cytokines, Growth Factors, and High-Sensitivity C-Reactive Protein Levels in Patients with Major Depression with and without Type 2 Diabetes Mellitus: An Explanatory Investigation

PURPOSE

We investigated the serum levels of cytokines, including interleukin 1β (IL-β), IL-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), and growth factors, including brain-derived neurotrophic factor, vascular endothelial growth factor, and insulin-like growth factor 1, and their association with major depression in patients with and without type 2 diabetes mellitus. We also investigated the response to antidepressant treatment in both groups.

PATIENTS AND METHODS

Forty-one patients with major depression were recruited at the University Hospital of Occupational and Environmental Health. All patients were diagnosed with major depression using the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition. Type 2 diabetes mellitus was diagnosed according to the criteria of the Japan Diabetes Society. Six healthy controls with no history of psychiatric or physical diseases were also enrolled. Serum levels of several cytokines, growth factors, and high-sensitivity C-reactive protein (hs-CRP) were measured. The clinical symptoms of patients with major depression were assessed using the Montgomery-Asberg Depression Rating Scale.

RESULTS

Significant differences in cytokines, growth factors, and hs-CRP were observed between the major depression and healthy control groups. Serum TNF-α levels were significantly higher in patients with major depression and type 2 diabetes mellitus than in those without type 2 diabetes mellitus. In the major depression group, serum IL-6 and hs-CRP levels tended to be higher in patients with type 2 diabetes mellitus than in those without. Several correlations among cytokines, growth factors, and hs-CRP were observed in patients with major depression with and without type 2 diabetes mellitus. Responses to pharmacological interventions for major depression did not differ between patients with and without type 2 diabetes mellitus.

CONCLUSION

Serum levels of TNF-α, hs-CRP, and IL-6 were different between patients with major depression with and without type 2 diabetes mellitus. Also, correlations were found between serum levels of cytokines, growth factors, and hs-CRP in patients with major depression. Inflammatory factors, which may be associated with growth factors, may be involved in the pathophysiology of major depression, particularly among patients with comorbid type 2 diabetes mellitus.

Isoforms of soluble vascular endothelial growth factor in stress-related mental disorders: a cross-sectional study

Vascular endothelial growth factor (VEGF) has been implicated in the pathophysiology of stress-related mental disorders. However, VEGF levels have seldom been compared across mental disorders and never by isoforms. Pathophysiological processes involving leakage of astrocyte-derived extracellular vesicles (EVs) across the blood–brain barrier could be associated with VEGF levels in patients with stress-related mental disorders. This cross-sectional study compared plasma levels of VEGF₁₂₁, VEGF₁₆₅, and VEGF₁₂₁ + VEGF₁₆₅ (VEGF_total) in patients with stress-induced exhaustion disorder (SED) (n = 31), patients with major depressive disorder (MDD) (n = 31), and healthy controls (n = 61). It also analyzed the correlation between VEGF and astrocyte-derived EVs in plasma. An enzyme-linked immunosorbent assay (ELISA) was used to measure VEGF₁₂₁ and VEGF₁₆₅ in citrate plasma, and flow cytometry was used to measure astrocyte-derived EVs in plasma. The mean concentration of soluble VEGF₁₂₁ (sVEGF₁₂₁) was significantly higher in patients with SED than healthy controls (P = 0.043). Mean sVEGF₁₆₅ was significantly lower in patients with MDD than patients with SED (P = 0.004) or healthy controls (P = 0.037). Mean sVEGF_total was significantly higher in patients with SED than in patients with MDD (P = 0.021) and also higher in patients with SED than healthy controls (P = 0.040). Levels of sVEGF₁₂₁ were positively correlated with levels of astrocyte-derived EVs only in patients with SED (P = 0.0128). The same was true of levels of sVEGF_total and astrocyte-derived EVs (P = 0.0046). Differing levels of VEGF isoforms may reflect different pathophysiological mechanisms in SED and MDD. Further research is needed to better understand the potential roles of VEGF isoforms and astrocyte-derived EVs in mental disorders.