Inflammatory cytokine network in schizophrenia

Induced pluripotent stem cell-derived astrocytes from patients with schizophrenia exhibit an inflammatory phenotype that affects vascularization

Molecular and functional abnormalities of astrocytes have been implicated in the etiology and pathogenesis of schizophrenia (SCZ). In this study, we examined the proteome, inflammatory responses, and secretome effects on vascularization of human induced pluripotent stem cell (hiPSC)-derived astrocytes from patients with SCZ. Proteomic analysis revealed alterations in proteins related to immune function and vascularization. Reduced expression of the nuclear factor kappa B (NF-κB) p65 subunit was observed in these astrocytes, with no incremental secretion of cytokines after tumor necrosis factor alpha (TNF-α) stimulation. Among inflammatory cytokines, secretion of interleukin (IL)-8 was particularly elevated in SCZ-patient-derived-astrocyte-conditioned medium (A_SCZCM). In a chicken chorioallantoic membrane (CAM) assay, A_SCZCM reduced the diameter of newly grown vessels. This effect could be mimicked with exogenous addition of IL-8. Taken together, our results suggest that SCZ astrocytes are immunologically dysfunctional and may consequently affect vascularization through secreted factors.

The Effect of TNF-alpha rs1800629 Polymorphism on White Matter Structures and Memory Function in Patients With Schizophrenia: A Pilot Study

OBJECTIVE

This study investigated the effect of TNF-α rs1800629 polymorphism on white matter integrity and memory function in patients with schizophrenia.

METHODS

Fifty-five participants with schizophrenia were enrolled in this study. They were genotyped for TNF-α rs1800629 polymorphism and underwent diffusion tensor imaging. Memory function was assessed using the Rey-Kim memory test. Participants with schizophrenia were grouped into GG homozygotes and A-allele carriers.

RESULTS

Compared to GG homozygotes, A-allele carriers had significantly lower scores for immediate and delayed recall and recognition of verbal memory and showed significantly lower fractional anisotropy in extensive brain regions. Lower total scores in immediate and delayed recall of verbal memory, immediate recall of visual memory, and figure copy of visual memory were significantly correlated with decreased mean fractional anisotropy in the white matter tracts of the corresponding brain regions.

CONCLUSION

Our findings suggest that the A-allele, which is associated with higher levels of TNF-α expression, correlates with lower connectivity of the fronto-temporal white matter compared to that in GG homozygotes. Impaired fronto-temporal connectivity may be associated with genetic vulnerability to schizophrenia, leading to verbal and visual memory deficits in patients with schizophrenia.

Linking Inflammation, Aberrant Glutamate-Dopamine Interaction, and Post-synaptic Changes: Translational Relevance for Schizophrenia and Antipsychotic Treatment: a Systematic Review

Evidence from clinical, preclinical, and post-mortem studies supports the inflammatory/immune hypothesis of schizophrenia pathogenesis. Less evident is the link between the inflammatory background and two well-recognized functional and structural findings of schizophrenia pathophysiology: the dopamine-glutamate aberrant interaction and the alteration of dendritic spines architecture, both believed to be the “quantal” elements of cortical-subcortical dysfunctional network. In this systematic review, we tried to capture the major findings linking inflammation, aberrant glutamate-dopamine interaction, and post-synaptic changes under a direct and inverse translational perspective, a paramount picture that at present is lacking. The inflammatory effects on dopaminergic function appear to be bidirectional: the inflammation influences dopamine release, and dopamine acts as a regulator of discrete inflammatory processes involved in schizophrenia such as dysregulated interleukin and kynurenine pathways. Furthermore, the link between inflammation and glutamate is strongly supported by clinical studies aimed at exploring overactive microglia in schizophrenia patients and maternal immune activation models, indicating impaired glutamate regulation and reduced N-methyl-D-aspartate receptor (NMDAR) function. In addition, an inflammatory/immune-induced alteration of post-synaptic density scaffold proteins, crucial for downstream NMDAR signaling and synaptic efficacy, has been demonstrated. According to these findings, a significant increase in plasma inflammatory markers has been found in schizophrenia patients compared to healthy controls, associated with reduced cortical integrity and functional connectivity, relevant to the cognitive deficit of schizophrenia. Finally, the link between altered inflammatory/immune responses raises relevant questions regarding potential new therapeutic strategies specifically for those forms of schizophrenia that are resistant to canonical antipsychotics or unresponsive to clozapine.

Adiponectin and Stnfr2 peripheral levels are associated with cardiovascular risk in patients with schizophrenia

OBJECTIVES

To investigate the association between cytokine peripheral levels and the risk of cardiovascular disease in patients with schizophrenia and controls.

METHODS

A sample of 40 patients and 40 control subjects participated in the study. Psychiatric diagnosis was established following structured clinical assessment. The Framingham Score was used to assess cardiovascular risk (CVR). Serum levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α were determined by cytometric bead array (CBA) technique, and the serum levels of IL-33, sST2, sTNFR1, sTNFR2, Leptin and Adiponectin by Enzyme-Linked Immunosorbent assay (ELISA).

RESULTS

Patients with schizophrenia showed greater frequency of moderate CVR when compared with controls (p = 0.14). In addition, patients showed higher levels of sTNFR2 and Adiponectin compared to controls (p = 0.007 and p < 0.001, respectively). Adiponectin and sTNFR2 were associated with CVR only in patients (p = 0.0002 and p = 0.033, respectively). In multivariate analysis controlling for socio-demographic and clinical confounders, illness duration (r = 0.492; p < 0.002) and sTNFR2 (r = 0.665; p < 0.004) were independent predictors of CVR.

CONCLUSION

Our results reinforce the concept that patients with schizophrenia are at greater risk to develop cardiovascular diseases, and suggest that the associated chronic low-grade inflammation might play a role in this process.

The Impact of SARS-CoV-2 Infection on Youth Mental Health: A Narrative Review

BACKGROUND

COVID-19 pandemic has affected the physical health, psychological wellbeing, and mental health of the whole population. Young people are among those most at risk of developing mental health symptoms or disorders related to the pandemic.

PURPOSE

the present narrative review is aimed at providing an updated overview of the current literature concerning the psychological impact of the SARS-CoV-2 infection but also of the COVID-19 outbreak, environmental restriction, and social distancing on mental health outcomes among the youth population aged between 15 and 25 years.

METHODS

in December 2021, an electronic search on this topic was performed on PubMed. Relevant publications from January 2020 until December 2021 were included.

FINDINGS

53 cross-sectional studies, 26 longitudinal studies, 4 ecological studies, 1 qualitative study, and 1 systematic review were included. We found many methodological limitations in the studies included, especially poor choice of study samples and short follow-ups. Little literature was in support of a strong relationship between SARS-CoV-2 infection and consequences on youth mental health. On the contrary, many studies showed how extraordinary measures to limit the spread of the virus have impacted young people in terms of onset of new mental disorders and symptoms, suicidality, and access to emergency psychiatric services. Depressive and anxiety symptoms and disorders show the greatest increase in incidence, especially in girls and young women.

CONCLUSIONS

it seems important to pay attention to the mental health of young people in relation to the consequences of the COVID-19 pandemic. However, studies with more robust methodologies and longer follow-ups are needed to establish precise indications for targeted interventions in this context.

The Transcriptome and Methylome of the Developing and Aging Brain and Their Relations to Gliomas and Psychological Disorders

Mutually linked expression and methylation dynamics in the brain govern genome regulation over the whole lifetime with an impact on cognition, psychological disorders, and cancer. We performed a joint study of gene expression and DNA methylation of brain tissue originating from the human prefrontal cortex of individuals across the lifespan to describe changes in cellular programs and their regulation by epigenetic mechanisms. The analysis considers previous knowledge in terms of functional gene signatures and chromatin states derived from independent studies, aging profiles of a battery of chromatin modifying enzymes, and data of gliomas and neuropsychological disorders for a holistic view on the development and aging of the brain. Expression and methylation changes from babies to elderly adults decompose into different modes associated with the serial activation of (brain) developmental, learning, metabolic and inflammatory functions, where methylation in gene promoters mostly represses transcription. Expression of genes encoding methylome modifying enzymes is very diverse reflecting complex regulations during lifetime which also associates with the marked remodeling of chromatin between permissive and restrictive states. Data of brain cancer and psychotic disorders reveal footprints of pathophysiologies related to brain development and aging. Comparison of aging brains with gliomas supports the view that glioblastoma-like and astrocytoma-like tumors exhibit higher cellular plasticity activated in the developing healthy brain while oligodendrogliomas have a more stable differentiation hierarchy more resembling the aged brain. The balance and specific shifts between volatile and stable and between more irreversible and more plastic epigenomic networks govern the development and aging of healthy and diseased brain.

Reduced Serum Levels of Soluble Interleukin-15 Receptor α in Schizophrenia and Its Relationship to the Excited Phenotype

Our previous studies documented that interleukin-15 receptor α (IL-15Rα) knockout (KO) mice exhibited hyperactivity, memory impairment, and desperate behavior, which are core features of schizophrenia and depression. Due to the overlapping symptomology and pathogenesis observed for schizophrenia and depression, the present study attempted to determine whether IL-15Rα was associated with the risk of schizophrenia or depression. One hundred fifty-six participants, including 63 schizophrenia patients, 29 depressive patients, and 64 age-matched healthy controls, were enrolled in the study. We investigated the circulating levels of soluble IL-15Rα and analyzed potential links between the IL-15Rα levels and clinical symptoms present in schizophrenia or depressive patients. We observed reduced serum IL-15Rα levels in schizophrenia patients, but not depressive patients compared with controls. Moreover, a significant negative association was observed between the circulating IL-15Rα levels and excited phenotypes in the schizophrenia patients. The IL-15Rα KO mice displayed pronounced pre-pulse inhibition impairment, which was a typical symptom of schizophrenia. Interestingly, the IL-15Rα KO mice exhibited a remarkable elevation in the startle amplitude in the startle reflex test compared to wild type mice. These results demonstrated that serum levels of soluble IL-15Rα were reduced in schizophrenia and highlighted the relationship of IL-15Rα and the excited phenotype in schizophrenia patients and mice.

Clozapine: Why Is It So Uniquely Effective in the Treatment of a Range of Neuropsychiatric Disorders?

Clozapine is superior to other antipsychotics as a therapy for treatment-resistant schizophrenia and schizoaffective disorder with increased risk of suicidal behavior. This drug has also been used in the off-label treatment of bipolar disorder, major depressive disorder (MDD), and Parkinson's disease (PD). Although usually reserved for severe and treatment-refractory cases, it is interesting that electroconvulsive therapy (ECT) has also been used in the treatment of these psychiatric disorders, suggesting some common or related mechanisms. A literature review on the applications of clozapine and electroconvulsive therapy (ECT) to the disorders mentioned above was undertaken, and this narrative review was prepared. Although both treatments have multiple actions, evidence to date suggests that the ability to elicit epileptiform activity and alter EEG activity, to increase neuroplasticity and elevate brain levels of neurotrophic factors, to affect imbalances in the relationship between glutamate and γ-aminobutyric acid (GABA), and to reduce inflammation through effects on neuron-glia interactions are common underlying mechanisms of these two treatments. This evidence may explain why clozapine is effective in a range of neuropsychiatric disorders. Future increased investigations into epigenetic and connectomic changes produced by clozapine and ECT should provide valuable information about these two treatments and the disorders they are used to treat.

Concordance of Immune-Related Markers in Lymphocytes and Prefrontal Cortex in Schizophrenia

Schizophrenia is a severe neuropsychiatric disorder associated with a wide array of transcriptomic and neurobiochemical changes. Genome-wide transcriptomic profiling conducted in postmortem brain have provided novel insights into the pathophysiology of this disorder, and identified biological processes including immune/inflammatory-related responses, metabolic, endocrine, and synaptic function. However, few studies have investigated whether similar changes are present in peripheral tissue. Here, we used RNA-sequencing to characterize transcriptomic profiles of lymphocytes in 18 nonpsychotic controls and 19 individuals with schizophrenia. We identified 2819 differentially expressed transcripts (P nominal < .05) in the schizophrenia group when compared to controls. Bioinformatic analyses conducted on a subset of 293 genes (P nominal < .01 and |log2 FC| > 0.5) highlighted immune/inflammatory responses as key biological processes in our dataset. Differentially expressed genes in lymphocytes were highly enriched in gene expression profiles associated with cortex layer 5a and immune cells. Thus, we investigated whether the changes in transcripts levels observed in lymphocytes could also be detected in the prefrontal cortex (PFC, BA10) in a second replication cohort of schizophrenia subjects. Remarkably, mRNA levels detected in the PFC and lymphocytes were in strong agreement, and measurements obtained using RNA-sequencing positively correlated with data obtained by reverse transcriptase-quantitative polymerase chain reaction analysis. Collectively, our work supports a role for immune dysfunction in the pathogenesis of schizophrenia and suggests that peripheral markers can be used as accessible surrogates to investigate putative central nervous system disruptions.

Cytokines dysregulation in schizophrenia: A systematic review of psychoneuroimmune relationship

INTRODUCTION

Schizophrenia is a multifactorial psychiatric disease with complex interactions among the brain and the immune system. A psycho-immune relationship underling schizophrenia is supported by several studies and integrates a specific area of knowledge - psychoneuroimmunology.

METHODS

A systematic review was performed by 2009 Preferred Reporting Items (PRISMA) recommendations. Based on the inclusion/exclusion criteria, publications with relevant information (evaluated by the Joanna Briggs Institute Critical Appraisals tools to quality assessment) were included.

RESULTS

In this review, we considered the inflammatory activity promoted by cytokine alterations in schizophrenia aetiology, which reflects the systemic comprehension of this disease in opposition to the traditional approach focused solely on the brain. We focus on the analysis of several specific outcomes, such as proinflammatory cytokines, sample sort, laboratory techniques, diagnosis scales and results of each publication.

CONCLUSION

This systematic review confirms the existence of cytokines abnormalities in schizophrenia disease. Immune imbalances such as increased levels of some cytokines (either at protein level or at mRNA expression), cytokine mRNAs, as well as cytokine gene polymorphisms have been reported with a large support in schizophrenia. These findings provide a strong evidence of a concomitant process of inflammatory activity in schizophrenia illness course.

Epigallocatechin gallate improves airway inflammation through TGF‑β1 signaling pathway in asthmatic mice

The present study aimed to investigate the effect of epigallocatechin gallate (EGCG) on airway inflammation in mice with bronchial asthma, and the regulatory mechanism of transforming growth factor (TGF)-β1 signaling pathway, so as to provide theoretical basis for research and development of a novel drug for clinical treatment. Mouse models of bronchial asthma were established and injected with dexamethasone and EGCG via the caudal vein. 7 days later, bronchoalveolar tissue was collected for hematoxylin and eosin staining. Determination of airway resistance (AWR) and lung function in mice was detected. Serum was separated for cytometric bead array to detect the changes in inflammatory factors. Bronchoalveolar lavage fluid was collected for eosinophil and neutrophil counts. Fresh blood was obtained for flow cytometry to determine the percentages of Th17 and Treg cells. Bronchovesicular tissue was utilized for western blot assay and reverse transcription-quantitative polymerase chain reaction to determine the proteins and transcription factors in the TGF-β1 pathway. EGCG 20 mg/kg significantly reduced asthmatic symptoms, lung inflammatory cell infiltration, and the inflammatory factor levels of interleukin (IL)-2, IL-6 and tumor necrosis factor (TNF)-α. In addition, it increased the levels of inflammatory factors, including IL-10, diminished the percentage of Th17 cells, increased the percentage of Treg cells, and decreased the expression of TGF-β1 and phosphorylated (p)-Smad2/3 expression. Following the inhibition of the TGF-β1 receptor, the anti-inflammatory effect of EGCG disappeared, and the expression of TGF-β1 and p-Smad2/3 increased. EGCG attenuated airway inflammation in asthmatic mice, decreased the percentage of Th17 cells and increased the percentage of Treg cells. The anti-inflammatory effect of EGCG is achieved via the TGF-β1 signaling pathway.

Abnormal gene and protein expression of inflammatory cytokines in the postmortem brain of schizophrenia patients

Immune function abnormalities have been implicated in the pathophysiology of schizophrenia (SZ). This is primarily based on the observation that the levels of proinflammatory cytokines are significantly increased in the serum of SZ patients compared with normal control (NC) subjects. However, it is not known if similar cytokines abnormalities are also present in the brain of SZ patients. To further examine the involvement of inflammatory cytokines in the brain of SZ patients, we determined the protein and mRNA levels of TNF-α, IL-1β, IL-2, IL-6, IL-8, IL-10, IL-13, LTA and IL-1RA in the prefrontal cortex (PFC, Brodmann area 9) of SZ patients. We found that the protein and mRNA expression levels of the cytokines TNF-α and IL-6 are significantly increased and those of IL-10 are significantly decreased in the PFC of SZ patients. No difference in the protein and mRNA levels of IL-1β, IL-13, and IL-1RA was observed between SZ patients and NC subjects. The protein expression levels of IL-8 were significantly decreased and those of LTA were significantly increased in SZ patients, but no significant difference in the mRNA levels of IL-8 and LTA was observed between SZ patients and NC subjects. The levels of IL-2 were undetectable or very low in the postmortem brain of either SZ or NC subjects. These results suggest abnormalities of specific pro- and anti-inflammatory cytokines in the postmortem brain of SZ patients. These observations may have important implications in understanding the role of inflammatory cytokines in the pathophysiology of SZ.

Autoimmunity and autoinflammation: A systems view on signaling pathway dysregulation profiles

INTRODUCTION

Autoinflammatory and autoimmune disorders are characterized by aberrant changes in innate and adaptive immunity that may lead from an initial inflammatory state to an organ specific damage. These disorders possess heterogeneity in terms of affected organs and clinical phenotypes. However, despite the differences in etiology and phenotypic variations, they share genetic associations, treatment responses and clinical manifestations. The mechanisms involved in their initiation and development remain poorly understood, however the existence of some clear similarities between autoimmune and autoinflammatory disorders indicates variable degrees of interaction between immune-related mechanisms.

METHODS

Our study aims at contributing to a holistic, pathway-centered view on the inflammatory condition of autoimmune and autoinflammatory diseases. We have evaluated similarities and specificities of pathway activity changes in twelve autoimmune and autoinflammatory disorders by performing meta-analysis of publicly available gene expression datasets generated from peripheral blood mononuclear cells, using a bioinformatics pipeline that integrates Self Organizing Maps and Pathway Signal Flow algorithms along with KEGG pathway topologies.

RESULTS AND CONCLUSIONS

The results reveal that clinically divergent disease groups share common pathway perturbation profiles. We identified pathways, similarly perturbed in all the studied diseases, such as PI3K-Akt, Toll-like receptor, and NF-kappa B signaling, that serve as integrators of signals guiding immune cell polarization, migration, growth, survival and differentiation. Further, two clusters of diseases were identified based on specifically dysregulated pathways: one gathering mostly autoimmune and the other mainly autoinflammatory diseases. Cluster separation was driven not only by apparent involvement of pathways implicated in adaptive immunity in one case, and inflammation in the other, but also by processes not explicitly related to immune response, but rather representing various events related to the formation of specific pathophysiological environment. Thus, our data suggest that while all of the studied diseases are affected by activation of common inflammatory processes, disease-specific variations in their relative balance are also identified.

DNA Methylation Changes in Intron 1 of Triggering Receptor Expressed on Myeloid Cell 2 in Japanese Schizophrenia Subjects

A hypothesis for schizophrenia (SCZ) called the “microglia hypothesis” has been suggested. In SCZ, expression of triggering receptor expressed on myeloid cell 2 (TREM2) mRNA is higher in leukocytes than in healthy individuals. Here, the methylation rates of four CpG sites in TREM2 intron 1 that may bind important transcription factors and the correlation between the methylation rate and mRNA expression were determined. We compared the methylation rates in SCZ patients and age-matched controls (n = 50 each). SCZ patients had significantly lower methylation rates of CpG 2 (17.0 ± 6.7 vs. 20.2 ± 5.0; p = 0.02) and CpG 3 (23.8 ± 8.2 vs. 28.1 ± 6.2; p = 0.01). The average methylation rate (15.3 ± 5.2 vs. 17.6 ± 3.9; p = 0.009) was also lower. A significant negative correlation was found between TREM2 mRNA expression and the methylation rate of CpG 2 (r = −0.252, p = 0.012). SCZ susceptibility markers may include low methylation at TREM2 intron 1 and increased TREM2 mRNA levels. Our pilot study requires validation with higher numbers of participants and with other myeloid cell types.

Serum high-sensitivity C-reactive protein: A delicate sentinel elevated in drug-free acutely agitated patients with schizophrenia

Increased levels of high-sensitivity C reactive protein (hsCRP) have been reported in schizophrenia, but to date, no study is designed to examine serum hsCRP in acutely agitated patients with schizophrenia, an extreme state that requires immediate diagnosis and medical treatment. Serum hsCRP levels were assessed in 32 clinically acutely agitated patients and 42 healthy control subjects matched for demographic properties. Further, serum hsCRP levels in acutely agitated patients were compared with control subjects and with the levels after the patients were treated with anti-psychiatric medications. Meanwhile, the influence of clinical subtypes, family history, and gender, as well as the levels of white blood cell (WBC) counts were also considered. In results, serum hsCRP levels were significantly higher in acutely agitated patients with schizophrenia than in healthy subjects. The elevation of serum hsCRP in patients was not affected by gender, family history (P>0.05), and clinical classification of schizophrenia (P>0.05). However, the elevation of hsCRP was suppressed by the medical treatment for schizophrenia with acute agitation (P<0.05). In addition, WBC counts, another inflammation-related indicator, were also increased significantly in acutely agitated patients compared with healthy subjects, consistent with the elevation of serum hsCRP. In conclusion, hsCRP is an important indicator of immune alterations in the pathogenesis of schizophrenia and has potential to be developed into a sensitive marker for the acute agitation in schizophrenia.

Blood-brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders

Background

Autism spectrum disorders (ASD) are complex conditions whose pathogenesis may be attributed to gene–environment interactions. There are no definitive mechanisms explaining how environmental triggers can lead to ASD although the involvement of inflammation and immunity has been suggested. Inappropriate antigen trafficking through an impaired intestinal barrier, followed by passage of these antigens or immune-activated complexes through a permissive blood–brain barrier (BBB), can be part of the chain of events leading to these disorders. Our goal was to investigate whether an altered BBB and gut permeability is part of the pathophysiology of ASD.

Methods

Postmortem cerebral cortex and cerebellum tissues from ASD, schizophrenia (SCZ), and healthy subjects (HC) and duodenal biopsies from ASD and HC were analyzed for gene and protein expression profiles. Tight junctions and other key molecules associated with the neurovascular unit integrity and function and neuroinflammation were investigated.

Results

Claudin (CLDN)-5 and -12 were increased in the ASD cortex and cerebellum. CLDN-3, tricellulin, and MMP-9 were higher in the ASD cortex. IL-8, tPA, and IBA-1 were downregulated in SCZ cortex; IL-1b was increased in the SCZ cerebellum. Differences between SCZ and ASD were observed for most of the genes analyzed in both brain areas. CLDN-5 protein was increased in ASD cortex and cerebellum, while CLDN-12 appeared reduced in both ASD and SCZ cortexes. In the intestine, 75% of the ASD samples analyzed had reduced expression of barrier-forming TJ components (CLDN-1, OCLN, TRIC), whereas 66% had increased pore-forming CLDNs (CLDN-2, -10, -15) compared to controls.

Conclusions

In the ASD brain, there is an altered expression of genes associated with BBB integrity coupled with increased neuroinflammation and possibly impaired gut barrier integrity. While these findings seem to be specific for ASD, the possibility of more distinct SCZ subgroups should be explored with additional studies.

Exercise-induced modulation of histone H4 acetylation status and cytokines levels in patients with schizophrenia

The present study aimed to investigate the short and long-term effects of a concurrent exercise protocol on global histone H4 acetylation levels and inflammatory markers (interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma (IFN-γ) and cortisol) in phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMC) and in peripheral blood of patients with schizophrenia (SZ), as well the intervention impact on anthropometric characteristics. Seventeen individuals were submitted to the intervention three times a week and blood samples were collected pre, 30, 60 and 90days after the intervention started. A remarkable reduction on body mass index and body mass were observed following intervention. The protocol also induced a histone H4 hypoacetylation status in PBMC all times evaluated when compared to the pre intervention period. Although the IL-4 and cortisol levels were not altered in response to the intervention, a reduction in IL-6 production during the 60 and 90days compared to the pre intervention period was observed. Finally, diminished IFN-γ production was found in the 90days period compared to the pre intervention and 30days after periods. In addition, systemic IL-6 levels were lower at 60 and 90days compared to the pre intervention. The concurrent exercise protocol was able to improve anthropometric characteristics in patients with SZ, engaging the modulation of cytokine and histone H4 acetylation levels.

Supra-therapeutic plasma concentrations of haloperidol induce moderate inhibition of lipopolysaccharide-induced interleukin-8 release in human monocytes

BACKGROUND

The clinical use of antipsychotics and mood-stabilizing drugs with proven efficacy is largely determined by the occurrence of treatment-emergent adverse events and routine clinical chemistry and haematology data, which together define the safety and tolerability profile of these psychopharmaceuticals. Whereas the effects of mood-stabilizing drugs on functional properties of blood cells have been poorly investigated, the effects of antipsychotics have received more attention. Such studies have yielded conflicting results. This study examined the effects of the mood-stabilizing drugs carbamazepine and valproic acid and of the antipsychotic drugs olanzapine, risperidone and haloperidol on the production of the pro-inflammatory chemokine interleukin-8 (IL-8), which is released from human monocytes when activated by Gram-negative lipopolysaccharide (LPS).

METHODS

Peripheral human whole blood was diluted with Roswell Park Memorial Institute (RPMI) cell culture medium and stimulated with LPS. Accumulating IL-8 was quantified in the supernatant with an adapted enzyme-linked immunosorbent assay (ELISA) and the results correlated to the number of monocytes at venipuncture.

RESULTS

At supra-therapeutic concentrations of 100 µM, haloperidol inhibited the LPS-induced release of IL-8 in peripheral human monocytes moderately, whereas olanzapine, risperidone, carbamazepine and valproic acid showed no such effect.

CONCLUSIONS

The results suggest that these mood-stabilizing drugs and antipsychotics are endowed with clinically favorable inertness rather than pro-inflammatory properties.

Effects of Electroconvulsive Therapy on Some Inflammatory Factors in Patients With Treatment-Resistant Schizophrenia

OBJECTIVES

Electroconvulsive therapy (ECT) is the most effective option for several psychiatric conditions, including treatment-resistant schizophrenia. However, little is known about the molecular mechanism of action of ECT. The link between inflammatory system and schizophrenia is the focus of recent studies. However, the impact of ECT on inflammatory functioning in this disorder remains elusive. Whether ECT could modulate inflammatory factors in patients with schizophrenia was examined.

METHODS

Plasma levels of interleukin-4 (IL-4), transforming growth factor-β (TGF-β), myeloperoxidase (MPO), and nuclear factor-κB (NF-κB) activation were analyzed in 20 schizophrenic patients, mainly with resistant to antipsychotic medication disorders, and in 20 sex- and age-matched healthy controls. Disease severity was evaluated using the Brief Psychiatric Rating Scale. All patients were followed with measurement of the inflammatory factors before and after ECT treatment and compared with the controls.

RESULTS

Patients with schizophrenia had markedly raised NF-κB and but decreased TGF-β levels compared with healthy controls. On the other hand, no significant differences were found for the levels of IL-4 and MPO levels. The clinical improvement during repeated ECT was accompanied by a gradual and significant increase in IL-4 and TGF-β level, but MPO and NF-κB activation were left unaffected. Increases in TGF-β were negatively correlated with the change in Brief Psychiatric Rating Scale scores after ECT.

CONCLUSIONS

It is shown that ECT, while increasing the anti-inflammatory response such as the levels of IL-4 and TGF-β, it did not affect the levels of MPO and NF-κB activation in this study.

For whom the endocannabinoid tolls: Modulation of innate immune function and implications for psychiatric disorders

Toll-like receptors (TLRs) mediate the innate immune response to pathogens and are critical in the host defence, homeostasis and response to injury. However, uncontrolled and aberrant TLR activation can elicit potent effects on neurotransmission and neurodegenerative cascades and has been proposed to trigger the onset of certain neurodegenerative disorders and elicit detrimental effects on the progression and outcome of established disease. Over the past decade, there has been increasing evidence demonstrating that the endocannabinoid system can elicit potent modulatory effects on inflammatory processes, with clinical and preclinical evidence demonstrating beneficial effects on disease severity and symptoms in several inflammatory conditions. This review examines the evidence supporting a modulatory effect of endocannabinoids on TLR-mediated immune responses both peripherally and centrally, and the implications for psychiatric disorders such as depression and schizophrenia.

Interaction of BDNF with cytokines in chronic schizophrenia

Brain-derived neurotrophic factor (BDNF) interacts with cytokines. Although both BDNF and cytokines occur at abnormal levels in schizophrenia patients, their interactions have not yet been examined. We therefore compared serum BDNF, TNF-α, interleukin (IL)-2, IL-6, and IL-8 levels in 92 chronically medicated schizophrenia patients and 60 healthy controls. We correlated these serum levels within these subject groups with each other and with clinical symptoms assessed according to the Positive and Negative Syndrome Scale (PANSS). Compared to the control group, the schizophrenia patients had significantly lower BDNF and TNF-α levels, and higher IL-2, IL-6, and IL-8 levels. The patients also showed a significant positive correlation between BDNF and both IL-2 and IL-8 levels, and low BDNF and TNF-α levels together were associated with poor performance on the PANSS cognitive factor. Thus, an interaction between cytokines and neurotrophic factors may be implicated in the pathophysiology of chronic schizophrenia. In particular, the cytokine TNF-α may interact with BNDF causing cognitive impairment.

Effects of olanzapine on LPS-induced inflammation in rat primary glia cells

Olanzapine (OLZ) is an atypical antipsychotic drug that also has mood-stabilizing effects. The mechanism of action of OLZ is not fully understood. Accumulating data suggest that inflammation plays a role in the pathophysiology of mental disorders and that psychotropic drugs exhibit some anti-inflammatory properties. This study was undertaken to examine the effects of OLZ on LPS-induced inflammation in rat primary glia cells. Glia cells were extracted from newborn rat brains. OLZ (1 or 50 µM) was added to culture medium at 6 or 72 h before addition of LPS for another 18 h, and levels of IL-10, prostaglandin (PG) E2, NO and TNF-α, and expression of cyclo-oxygensase (COX)-2 and inducible NO synthase (iNOS) were determined. Treatment with 50 µM OLZ (but not 1 µM) significantly decreased LPS-induced secretion of IL-10, PGE2 and TNF-α. In contrast, 50 µM OLZ significantly increased NO levels. OLZ did not alter the expression of COX-2 or iNOS in LPS-treated cells. These results suggest that OLZ differently affects the secretion of inflammatory mediators. Most of the significant effects of OLZ were obtained when 50 µM was used, which is a high and probably therapeutically irrelevant concentration. Therefore, under the conditions used in the present study OLZ seemed to lack a potent anti-inflammatory effect.

Anti-inflammatory strategies in the treatment of schizophrenia

Schizophrenia is a major mental illness with a lifetime prevalence of about 1%. Antipsychotic drugs, with a primary mechanism of action that involves dopamine receptor blockade, are the mainstay in the treatment of the disorder. However, despite optimum antipsychotic treatment, few patients return to pre-morbid levels; the treatment deficit includes refractory positive symptoms, negative symptoms, mood impairments, cognitive impairments, social impairments, and/or a variety of medication-related adverse effects, including extrapyramidal symptoms, metabolic disturbances, hyperprolactinemia, and others. To address these, antipsychotic treatment has been augmented with psychosocial interventions, cognitive rehabilitation, different kinds of electrical and magnetic brain stimulation, and a large range of drugs from the neuropsychiatric as well as, surprise, the general medical pharmacopeia. The pleomorphic pathophysiology of schizophrenia includes abnormalities in immunological and inflammatory pathways, and so it is not surprising that anti-inflammatory drugs have also been trialed as augmentation agents in schizophrenia. This article critically examines the outcomes after augmentation with conventional anti-inflammatory interventions; results from randomized controlled trials do not encourage the use of either aspirin (1000 mg/day) or celecoxib (400 mg/day), both of which have been studied for this indication during the past decade and a half.

IL-6, IL-18, sIL-2R, and TNFα proinflammatory markers in depression and schizophrenia patients who are free of overt inflammation

Major depressive disorder (MDD) and schizophrenia are associated with inflammatory processes. Studies have shown that these disorders exhibit increase in the level of one or more proinflammatory markers. However, these studies did not exclude patients with obvious inflammation (i.e., CRP>6mg/L). Therefore, a comprehensive study should include those inflammatory disorders. In the present study, the inflammatory natures of MDD and schizophrenia were investigated. To achieve this goal, serum levels of interleukin-6 (IL-6), interleukin-18 (IL-18), tumor necrosis factor alpha (TNFα), and soluble interleukin 2 receptor (sIL-2R) in depressed and schizophrenic patients were obtained and compared with those of the control group. Results showed a significant increase (p<0.05) in serum levels of IL-6, IL-18, TNFα, and sIL-2R in MDD and schizophrenic patients compared with the control group. Also patients with schizophrenia group showed higher levels of the inflammatory markers than MDD and control groups. The current study concluded that the immunological response in the MDD and schizophrenic patients groups was significantly stimulated. These disorders may be considered an inflammatory disorder because of elevated levels of proinflammatory cytokines in spite of lacking an overt inflammation. Furthermore results of this study suggested the possibility of the use of anti-inflammatory drugs as adjuvant therapy in schizophrenic and depressive disorders.

Proinflammatory cytokines and their membrane-bound receptors are altered in the lymphocytes of schizophrenia patients

Abnormalities of protein levels of proinflammatory cytokines and their soluble receptors have been reported in the plasma/serum of schizophrenia (SZ) patients. To examine if SZ is also associated with the abnormal gene expression of cytokines and their membrane-bound receptors, we studied mRNA expression of proinflammatory cytokines and their receptors in lymphocytes of SZ patients and normal control (NC) subjects. We determined the protein and mRNA expression of proinflammatory cytokines and mRNA expression of their receptors in lymphocytes from 30 SZ patients and 30 drug-free NC subjects. The subjects were diagnosed according to DSM-IV criteria. Protein levels of cytokines were determined by ELISA, and mRNA levels in lymphocytes were determined by the qPCR method. We found that the mRNA levels of IL-6, TNF-α, IL-1R1, TNFR1, and TNFR2, but not IL-1β, IL-1R2, IL-1RA, IL-6R, or GP130 were significantly increased in lymphocytes of SZ patients compared with NC subjects. We also found that the protein expression of IL-6 and TNF-α, but not IL-1β, was also significantly increased in SZ patients compared with NC subjects. These studies suggest that in addition to the reported abnormalities of proinflammatory cytokines and their soluble receptors in the plasma of SZ patients, an abnormal gene expression of these cytokines and their membrane-bound receptors may be involved in the pathogenesis of SZ.

The neurobiology and treatment of first-episode schizophrenia

It is evident that once psychosis is present in patients with schizophrenia, the underlying biological process of the illness has already been ongoing for many years. At the time of diagnosis, patients with schizophrenia show decreased mean intracranial volume (ICV) as compared with healthy subjects. Since ICV is driven by brain growth, which reaches its maximum size at approximately 13 years of age, this finding suggests that brain development in patients with schizophrenia is stunted before that age. The smaller brain volume is expressed as decrements in both grey and white matter. After diagnosis, it is mainly the grey matter loss that progresses over time whereas white matter deficits are stable or may even improve over the course of the illness. To understand the possible causes of the brain changes in the first phase of schizophrenia, evidence from treatment studies, postmortem and neuroimaging investigations together with animal experiments needs to be incorporated. These data suggest that the pathophysiology of schizophrenia is multifactorial. Increased striatal dopamine synthesis is already evident before the time of diagnosis, starting during the at-risk mental state, and increases during the onset of frank psychosis. Cognitive impairment and negative symptoms may, in turn, result from other abnormalities, such as NMDA receptor hypofunction and low-grade inflammation of the brain. The latter two dysfunctions probably antedate increased dopamine synthesis by many years, reflecting the much earlier presence of cognitive and social dysfunction. Although correction of the hyperdopaminergic state with antipsychotic agents is generally effective in patients with a first-episode psychosis, the effects of treatments to correct NMDA receptor hypofunction or low-grade inflammation are (so far) rather modest at best. Improved efficacy of these interventions can be expected when they are applied at the onset of cognitive and social dysfunction, rather than at the onset of psychosis.

Sex differences in TGFB-β signaling with respect to age of onset and cognitive functioning in schizophrenia

There are studies showing that gene polymorphisms within the transforming growth factor-β (TGF-β) signaling constitute schizophrenia risk variants. However, the association between TGFB1 gene polymorphisms (+869T/C and +915G/C), TGF-β level with schizophrenia course, and its symptomatology together with cognitive functioning has not been investigated so far. We included 151 patients with schizophrenia and 279 healthy controls. Cognitive functioning was assessed using Rey Auditory Verbal Learning Test, Trail Making Test (TMT)-A and TMT-B, Verbal Fluency task, Stroop test, as well as selected subtests from the Wechsler Adults Intelligence Scale - Revised, Polish adaptation (WAIS-R-Pl): Digit Symbol Coding, Digit Span Forward and Backward, and Similarities. Additionally, serum TGF-β levels were measured in 88 schizophrenia patients and 88 healthy controls. Serum TGF-β level was significantly higher among patients with schizophrenia in comparison with healthy controls; however, the studied polymorphisms were not associated with TGF-β level in schizophrenia patients. Subjects carrying the +869T allele performed significantly worse in comparison with +869CC homozygotes on Stroop task, Verbal Fluency task and Digit Symbol Coding task. There was a significant difference in age of psychosis onset in female schizophrenia patients with respect to the TGFB1 +869T/C polymorphism. Additionally, adjustment for possible confounders revealed that there was a significant difference in cognitive performance on Digit Symbol Coding task with respect to the TGFB1 +869T/C polymorphism among female schizophrenia patients. Our results suggest that TGF-β signaling might be a valid link contributing to observed differences in age of onset and the level of cognitive decline between male and female schizophrenia patients.

Regulation of interleukin-6 and leptin in schizophrenia patients: a preliminary analysis

Objective

Immune-inflammatory mediators play a pivotal role in brain signaling and have been increasingly associated with the pathophysiology of schizophrenia. Many studies have indicated an increased level of immune-inflammatory interleukin-6 (IL-6) in schizophrenia. IL-6 is a well-known chief stimulator of inflammation. Of late leptin has also been implicated in the inflammatory pathway of schizophrenia. In this study we measured and compared serum levels of IL-6 and leptin in patients with schizophrenia to healthy controls, and investigated the relationship between IL-6 and leptin.

Methods

Serum IL-6 and leptin were determined in 20 patients diagnosed with schizophrenia and in 19 healthy controls matched by gender, age and body mass index (BMI) using commercial Bioplex assays.

Results

Using Mann-Whitney U-test, significantly increased IL-6 levels were found in the patients but there was no significant difference in leptin levels though a trend towards higher leptin was observed in the patients. Spearman correlations did not show any correlation between IL-6 and clinical variables except antipsychotic dosage. Leptin significantly correlated with gender and BMI. A large effect size correlation was observed between IL-6 and leptin in the patients but not in the controls. Multiple regression analysis performed on patients, after adjusting for gender and BMI, revealed there was no significant association between IL-6 and leptin.

Conclusion

IL-6 and leptin levels may reflect the chronic inflammatory state associated with schizophrenia but further evaluation is required. Also, it is important to consider the confounding effects of obesity in any examination of relationships between groups with regard to cytokines and adipokines.

Cryoglobulins as potential triggers of inflammation in schizophrenia

This case study aimed to investigate effects of type III cryoglobulins isolated from the blood of patients with schizophrenia on the production of proinflammatory cytokines interleukin(IL)-1 β , IL-6 and tumor necrosis factor- α (TNF- α ), anti-inflammatory cytokine IL-10, and chemotactic cytokines IL-8 and monocyte chemoattractant protein-1 (MCP-1) by peripheral blood mononuclear cells (PBMCs). The experiments were performed in vitro using PBMCs healthy subjects and the blood of patients whit schizoprenia. The enzyme-linked immunosorbent assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay were used upon study. The results obtained indicated significant increase (P < 0.05) in IL-1 β , IL-6, TNF- α , IL-8, and MCP-1 production by cultured PBMCs when incubating for 24 hours with cryoglobulins, beginning from 0.4 mg/mL. The gender difference does not affect the cryoglobulins-induced production of these cytokines by PBMCs. No influence of cryoglobulins on production of IL-10 by PBMCs was observed. Also, it was shown that cryoglobulins in concentration ≤4 mg/mL possessed no cytotoxic effect towards cultured PBMCs. Based upon the results obtained, we concluded that type III cryoglobulins are implicated in schizophrenia-associated alterations in the immune response through induction of the expression of proinflammatory and chemotactic cytokines by PBMCs.