Cytokines in schizophrenia: possible role of anti-inflammatory medications in clinical and preclinical stages

The association between inflammation and kynurenine pathway metabolites in electroconvulsive therapy for schizophrenia: Implications for clinical efficacy

The kynurenine pathway (KP) of tryptophan has been implicated in the pathogenesis of schizophrenia and its interaction with the immune system has been suggested to play a role. In this study, 28 schizophrenia patients and 25 healthy controls were recruited and divided into different inflammatory subgroups using a two-step recursive clustering analysis. Cytokine gene expression and plasma KP metabolites were measured before, during and after treatment. Our findings indicated that schizophrenia patients had lower levels of Tryptophan (TRP), N-formylkynurenine (NFK), xanthinic acid (XA), quinolinic acid (QA), kynurenic acid (KYNA), KYNA/KYN and QA/KYNA, but higher levels of IL-18 mRNA, KYN/TRP compared to healthy controls (all p < 0.05). After electroconvulsive therapy (ECT), patients with low inflammation achieved better clinical improvement (PANSS scores) compared to those with high inflammation (F = 5.672, P = 0.025), especially in negative symptoms (F = 6.382, P = 0.018, η2 = 0.197). While IL-18 mRNA (F = 32.910, P < 0.0001) was significantly decreased following ECT, the KYN/TRP (F = 3.455, p = 0.047) and KYNA/TRP (F = 4.264, P = 0.026) only significantly decreased in patients with low inflammation. Correlation analyses revealed that baseline IL-18 gene expression significantly correlated with pre- (r = 0.537, p = 0.008) and post-KYNA/TRP (r = 0.443, p = 0.034), post-KYN/TRP (r = 0.510, p = 0.013), and post-negative symptoms (r = 0.525, p = 0.010). Moreover, baseline TRP (r = -0.438, p = 0.037) and XA (r = -0.516, p = 0.012) were negatively correlated with baseline PANSS, while post-KYN (r = -0.475, p = 0.022), 2-AA (r = -0.447, p = 0.032) and KYN/TRP (r = -0.566, p = 0.005) were negatively correlated with Montreal Cognitive Assessment (MoCA) following ECT. Overall, these findings suggested that the association between inflammation and kynurenine pathway plays an essential role in mechanism of ECT for schizophrenia and that the regulation of ECT on KP is influenced by inflammatory characteristics, which may relate to clinical efficacy in schizophrenia.

The Microbiota–Gut–Brain Axis in Psychiatric Disorders

Modulating the gut microbiome and its influence on human health is the subject of intense research. The gut microbiota could be associated not only with gastroenterological diseases but also with psychiatric disorders. The importance of factors such as stress, mode of delivery, the role of probiotics, circadian clock system, diet, and occupational and environmental exposure in the relationship between the gut microbiota and brain function through bidirectional communication, described as “the microbiome–gut–brain axis”, is especially underlined. In this review, we discuss the link between the intestinal microbiome and the brain and host response involving different pathways between the intestinal microbiota and the nervous system (e.g., neurotransmitters, endocrine system, immunological mechanisms, or bacterial metabolites). We review the microbiota alterations and their results in the development of psychiatric disorders, including major depressive disorder (MDD), schizophrenia (SCZ), bipolar disorder (BD), autism spectrum disorder (ASD), and attention-deficit hyperactivity disorder (ADHD).

Cytokine Level and Symptoms of Schizophrenia

BACKGROUND: The study was intended to find one of the cytokines, that is, tumor necrosis factor (TNF)-alpha correlation with PANSS scores of people with schizophrenia (PwS) and their differences compared to the healthy people of Malayan- Mongoloid Race. AIM: The aim of this study was providing a profile of TNF-alpha level in PwS of Malayan-Mongoloid race and its correlation with positive and negative symptoms in schizophrenia. METHODS: It was conducted using cross-sectional and following sampling methods, with inclusion and exclusion criteria set for the PwS and control groups. RESULTS: The result was no correlation between TNF-alpha levels with PANSS scores on PwS (p > 0.005), with very weak correlation and positive correlation direction, and there were differences in TNF-alpha levels.between PwS and control groups. CONCLUSION: It can be concluded that the higher levels of TNF-alpha would impact on the severity symptoms experienced by PwS.

Resveratrol Adjunct Therapy for Negative Symptoms in Patients With Stable Schizophrenia: A Double-Blind, Randomized Placebo-Controlled Trial

BACKGROUND

Patients with schizophrenia can generally manifest a broad variety of primary negative symptoms. The current study aimed to assess the efficacy and tolerability of resveratrol add-on therapy in the treatment of negative symptoms in patients with stable schizophrenia.

METHODS

In a randomized, double-blind, and placebo-controlled setting, schizophrenia patients were assigned to receive either 200 mg/d resveratrol or matched placebo in addition to a stable dose of risperidone for 8 weeks. Patients were assessed using the positive and negative syndrome scale, the extrapyramidal symptom rating scale, and Hamilton Depression Rating Scale over the trial period. The primary outcome was considered as the change in positive and negative subscale score from baseline to week 8 between the treatment arms.

RESULTS

A total 52 patients completed the trial (26 in each arm). Baseline characteristics of both groups were statistically similar (P  > .05). Despite the statistically similar behavior of positive symptoms between the groups across time (Greenhouse-Geisser corrected: F = 1.76, df = 1.88, P = .180), the resveratrol group demonstrated greater improvement in negative, general psychopathology, and total scores (Greenhouse-Geisser corrected: F = 12.25, df = 2.04, P < .001; F = 5.42, df = 1.56, P = .011; F = 7.64, df = 1.48, P = .003). HDRS scores and its changes, ESRS score, and frequency of other complications were not significantly different between resveratrol and placebo groups.

CONCLUSION

Adding resveratrol to risperidone can exhibit remarkable efficacy and safety in terms of management of schizophrenia-related negative symptoms.

Cyclooxygenase Inhibition Safety and Efficacy in Inflammation-Based Psychiatric Disorders

According to the World Health Organization, the major psychiatric and neurodevelopmental disorders include major depression, bipolar disorder, schizophrenia, and autism spectrum disorder. The potential role of inflammation in the onset and progression of these disorders is increasingly being studied. The use of non-steroidal anti-inflammatory drugs (NSAIDs), well-known cyclooxygenase (COX) inhibitors, combined with first-choice specific drugs have been long investigated. The adjunctive administration of COX inhibitors to classic clinical treatments seems to improve the prognosis of people who suffer from psychiatric disorders. In this review, a broad overview of the use of COX inhibitors in the treatment of inflammation-based psychiatric disorders is provided. For this purpose, a critical analysis of the use of COX inhibitors in the last ten years of clinical trials of the major psychiatric disorders was carried out.

The effect of minocycline on amelioration of cognitive deficits and pro-inflammatory cytokines levels in patients with schizophrenia

BACKGROUND

Cognitive deficits of schizophrenia are predictors of poor function, but antipsychotic medication has limited efficacy for cognitive deficits. These deficits in learning and memory may result from activity of pro-inflammatory cytokines, which microglia produce. The microglia inhibitor minocycline might arrest this cytokine damage to the hippocampus and reverse the cognitive deficits of schizophrenia.

METHODS

A double-blind, placebo-controlled study involved 75 patients with schizophrenia who randomly received low dose (100 mg/day) or high dose minocycline (200 mg/day) or placebo added to risperidone. MATRICS Consensus Cognitive Battery (MCCB) was used to assess the cognitive functioning, and serum levels of Interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) were assessed.

RESULTS

Minocycline_{high dose} group was significantly superior to minocycline_{low dose} or placebo group not only for the improvements in cognitive tests' scores as well (P < 0.05), but for IL-1β and IL-6 serum levels reduction (P < 0.01). The amelioration of cognitive deficits with minocycline correlated not only with the remission of negative symptoms, but also with the reduction in serum levels of IL-1β and IL-6.

CONCLUSIONS

Minocycline adjunctive treatment was effective in improving cognitive deficits of patients with schizophrenia. The beneficial effect of minocycline may be related to reducing pro-inflammatory cytokines through microglia inhibition.

Proinflammatory and anti-inflammatory biomarkers in schizophrenia and influence of simvastatin on the interleukin-6

The present study sought to assess biomarkers of inflammation in stable patients with schizophrenia (SZ) on clozapine therapy. We recruited 60 outpatients with SZ and 60 healthy controls, matched for sex and age. Compared with controls, patients had significantly increased concentrations of interleukin-6 and tumor necrosis factor-α. Interestingly, patients on simvastatin had lower interleukin-6 levels compared with patients not on simvastatin and controls. This study corroborated previous evidence for increased inflammatory biomarkers in SZ and detected a potential anti-inflammatory action of simvastatin in patients with a clinical diagnosis of SZ on clozapine therapy.

C-Reactive Protein: Higher During Acute Psychotic Episodes and Related to Cortical Thickness in Schizophrenia and Healthy Controls

There is increasing evidence for the role of inflammation in schizophrenia, yet the stability of increased peripheral inflammation in acute psychosis and the degree to which peripheral inflammation relates to cortical thickness, a measure of the degree of neuropathology, are unknown. In independent samples, we assessed the peripheral inflammation marker C-reactive protein (CRP) to determine the extent to which: (1) CRP was elevated and stable across admissions for acute psychosis, (2) cognition, daily function and symptom severity are characteristic of chronically ill patients with schizophrenia displaying elevated CRP, and (3) CRP levels predict cortical thickness. Study 1 assessed peripheral CRP (primary outcome) and other blood measures in 174/280 people with acute psychosis while Study 2 assessed peripheral CRP, cognition and cortical thickness (primary outcomes), symptoms, and daily function in 85/97 chronically ill patients with schizophrenia and 71/87 healthy controls. In acute psychosis, CRP and neutrophil-to-lymphocyte ratio were significantly elevated relative to a normal cutoff (with 59.8% of patients having elevated CRP) which remained elevated across admissions. CRP was significantly elevated in 43% of chronically ill patients with schizophrenia compared to 20% in controls. Elevated CRP patients displayed significantly worse working memory and CRP was inversely correlated with cortical thickness in frontal, insula, and temporal brain regions. This work supports the role of inflammation in psychotic illnesses and suggests that use of peripheral markers (e.g., CRP) in conjunction with diagnosis could be used to identify patients with more cortical neuropathology and cognitive deficits.

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.

Neuroimmune Impacts of Early-Life Stress on Development and Psychopathology

Maltreatment and trauma in childhood, termed early-life stress (ELS), has long-term effects on the immune system. ELS impacts immune signaling at the time of exposure but also disrupts the developmental trajectory of certain immunological processes, both in the periphery and in the brain. One consequence of these early alterations is a heightened immune response to stressors later in life. However, chronic and sustained inflammatory response can also lead to excitotoxicity and prevent typical brain development. In this chapter, we discuss current progress toward understanding the contribution of neuroimmune signaling to ELS-attributable dysfunction or maladaptation with a focus on postnatal experiences. To do so we first present an operational definition of ELS. Then, we offer a brief overview of the immune system and neuroimmune development, followed by a section discussing the interaction between immunity, childhood trauma, and mental disorders in humans. We present evidence from animal models about immune alterations after ELS and discuss the ways in which ELS-induced immune changes ultimately affect brain and behavior, as well as the importance of individual differences and future directions in this field. Taken together, we submit that when encountered with ELS, some core brain circuits could develop differently via various mechanisms involving dysfunctional immune reprograming. However, given the remarkable plasticity of both the brain and the immune system, many of the deleterious effects of ELS may be mitigated with interventions that account for sex and target neuroimmune interactions over the lifespan.

Antioxidant and anti-inflammatory nutrient status, supplementation, and mechanisms in patients with schizophrenia

Over 50 million people around the world suffer from schizophrenia, a severe mental illness characterized by misinterpretation of reality. Although the exact causes of schizophrenia are still unknown, studies have indicated that inflammation and oxidative stress may play an important role in the etiology of the disease. Pro-inflammatory cytokines are crucial for normal central nervous development and proper functioning of neural networks and neurotransmitters. Patients with schizophrenia tend to have abnormal immune activation resulting in elevated pro-inflammatory cytokine levels, ultimately leading to functional brain impairments. Patients with schizophrenia have also been found to suffer from oxidative stress, a result of an imbalance between the production of free radicals and the ability to detoxify their harmful effects. Furthermore, inflammation and oxidative stress are implicated to be related to the severity of psychotic symptoms. Several nutrients are known to have anti-inflammatory and antioxidant functions through various mechanisms in our body. The present review evaluates studies and literature that address the status and supplementation of omega-3 polyunsaturated fatty acids, vitamin D, B vitamins (B6, folate, B12), vitamin E, and carotenoids in different stages of schizophrenia. The possible anti-inflammatory and antioxidant mechanisms of action of each nutrient are discussed.

Simvastatin adjunct therapy for negative symptoms of schizophrenia: a randomized double-blind placebo-controlled trial

We investigated the effects of simvastatin adjunctive therapy on the negative symptoms of schizophrenia. In this double-blind trial, inpatients with chronic schizophrenia were clinically stabilized on a constant dose of risperidone for at least 4 weeks before the study and were then randomized to receive risperidone (4-6 mg/day) plus either simvastatin (40 mg/day) (n=33) or placebo (n=33) for 8 weeks. The Positive and Negative Syndrome Scale was used to measure the negative, positive, and general symptoms of schizophrenia at baseline and every 2 weeks. The Hamilton Depression Rating Scale and the Extrapyramidal Symptom Rating Scale were used to measure depression and extrapyramidal symptoms at baseline and week 8. Difference in change in negative symptoms score from the baseline to week 8 was considered the single primary outcome. At baseline, negative symptoms scores were higher than positive symptoms scores in both simvastatin and placebo groups. There was no baseline difference between the two groups in terms of any of the measured variables. Compared with the placebo group, the simvastatin group showed a significantly higher reduction in negative symptoms scores from baseline to week 8 [mean difference: 95% confidence interval=-1.42 (-2.32 to -0.52), P=0.003]. Similar findings were observed for total scores [mean difference: 95% confidence interval=-1.85 (-2.87 to -0.83), P=0.001]. The results were not significant for positive symptoms or general psychopathology scores. We found a favorable effect of simvastatin on negative symptoms of patients with schizophrenia; however, future studies are warranted to confirm these results.

Peripheral immuno-inflammatory abnormalities in ultra-high risk of developing psychosis

BACKGROUND

Immuno-inflammatory imbalances have been documented in schizophrenia, but very little is known about the immunological changes prior to the onset of disease.

OBJECTIVE

This work aimed to compare serum levels of pro- and anti-inflammatory cytokines in young subjects at ultra-high risk (UHR) of developing psychosis with age- and sex-matched healthy controls.

METHODS

A total of 12 UHR and 16 age- and sex-matched healthy controls (HC) subjects were enrolled in this study. Clinical profile was assessed using the Comprehensive Assessment of At-Risk Mental States (CAARMS), Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I) or Kiddie-SADS-Present and Lifetime Version (K-SADS-PL), and Global Assessment of Functioning (GAF) scale. Serum interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, IFN-γ, and IL-17 were measured by flow cytometry using the Th1/Th2/Th17 cytometric bead array.

RESULTS

Compared with the healthy control group, patients in UHR showed increased IL-6 levels (Z=-2.370, p=0.018) and decreased IL-17 levels in serum (Z=-1.959, p=0.050). Levels of IL-17 positively correlated to the values in GAF symptoms (rho=0.632, p=0.028).

CONCLUSION

Our results suggest that immunological imbalances could be present in the early stages of psychosis, including in at-risk stages. Future studies should replicate and expand these results.

Family-based association study of interleukin 10 (IL10) and interleukin 10 receptor alpha (IL10RA) functional polymorphisms in schizophrenia in Polish population

Schizophrenia is a heterogeneous disorder and its etiology remains incompletely elucidated. Among possible causes, immunological factors have been implicated in its pathogenesis and course. Interleukin-10 (IL10) and it's receptor IL10RA may play an important role for immunological aspects in etiologies of major psychiatric disorders including schizophrenia. The aim of this study was to perform a transmission disequilibrium test (TDT) on a group of 146 schizophrenia trios from the Polish population. Functional polymorphisms from IL10 (rs1800872, rs1800871, rs1800896, rs1800890, and rs6676671) and IL10RA (rs3135932 and rs2229113) genes were analyzed. A lack of association with schizophrenia was detected for IL10 and IL10RA single polymorphisms and haplotypes.

Vitamin D in schizophrenia: a clinical review

Vitamin D (vitD) is known for its essential role in calcium homeostasis and bone health. VitD is made endogenously in the skin from UVB radiation from sunlight. VitD is now considered as a potent neurosteroid hormone, critical to brain development and normal brain function, and is known for its anti-inflammatory property affecting various aspects of human health. VitD ligand-receptor, a receptor that mediates much of vitD's biological actions, has been found throughout the body including the central nervous system. VitD deficiency is common in patients with severe mental illness such as schizophrenia. Schizophrenia is a debilitating chronic mental illness characterised by positive symptoms, such as hallucinations and delusions, and negative symptoms including flat affect and lack of motivation. Several environmental risk factors for schizophrenia, such as season of birth, latitude and migration, have been linked to vitD deficiency. Recent studies have suggested a potential role of vitD in the development of schizophrenia. For example, neonatal vitD status is associated with the risk of developing schizophrenia in later life obesity, insulin resistance, diabetes, hyperlipidaemia and cardiovascular disease, which are commonly seen in patients with schizophrenia. It has been well established that vitD deficiency is related to these metabolic problems. The biological mechanism is most likely related to vitD's action on the regulation of inflammatory and immunological processes, consequently affecting the manifestation of clinical symptoms and treatment response of schizophrenia. Potential benefits of vitD supplementation to improve schizophrenia symptoms as well as physical health in patients with schizophrenia should be further explored in future studies.

Changes in Astroglial Markers in a Maternal Immune Activation Model of Schizophrenia in Wistar Rats are Dependent on Sex

Data from epidemiological studies suggest that prenatal exposure to bacterial and viral infection is an important environmental risk factor for schizophrenia. The maternal immune activation (MIA) animal model is used to study how an insult directed at the maternal host can have adverse effects on the fetus, leading to behavioral and neurochemical changes later in life. We evaluated whether the administration of LPS to rat dams during late pregnancy affects astroglial markers (S100B and GFAP) of the offspring in later life. The frontal cortex and hippocampus were compared in male and female offspring on postnatal days (PND) 30 and 60. The S100B protein exhibited an age-dependent pattern of expression, being increased in the frontal cortex and hippocampus of the MIA group at PND 60, while at PND 30, male rats presented increased S100B levels only in the frontal cortex. Considering that S100B secretion is reduced by elevation of glutamate levels, we may hypothesize that this early increment in frontal cortex tissue of males is associated with elevated extracellular levels of glutamate and glutamatergic hypofunction, an alteration commonly associated with SCZ pathology. Moreover, we also found augmented GFAP in the frontal cortex of the LPS group at PND 30, but not in the hippocampus. Taken together data indicate that astroglial changes induced by MIA are dependent on sex and brain region and that these changes could reflect astroglial dysfunction. Such alterations may contribute to our understanding of the abnormal neuronal connectivity and developmental aspects of SCZ and other psychiatric disorders.

Association study of functional polymorphisms in interleukins and interleukin receptors genes: IL1A, IL1B, IL1RN, IL6, IL6R, IL10, IL10RA and TGFB1 in schizophrenia in Polish population

Schizophrenia has been associated with a large range of autoimmune diseases, with a history of any autoimmune disease being associated with a 45% increase in risk for the illness. The inflammatory system may trigger or modulate the course of schizophrenia through complex mechanisms influencing neurodevelopment, neuroplasticity and neurotransmission. In particular, increases or imbalance in cytokine before birth or during the early stages of life may affect neurodevelopment and produce vulnerability to the disease. A total of 27 polymorphisms of IL1N gene: rs1800587, rs17561; IL1B gene: rs1143634, rs1143643, rs16944, rs4848306, rs1143623, rs1143633, rs1143627; IL1RN gene: rs419598, rs315952, rs9005, rs4251961; IL6 gene: rs1800795, rs1800797; IL6R gene: rs4537545, rs4845617, rs2228145, IL10 gene: rs1800896, rs1800871, rs1800872, rs1800890, rs6676671; IL10RA gene: rs2229113, rs3135932; TGF1B gene: rs1800469, rs1800470; each selected on the basis of molecular evidence for functionality, were investigated in this study. Analysis was performed on a group of 621 patients with diagnosis of schizophrenia and 531 healthy controls in Polish population. An association of rs4848306 in IL1B gene, rs4251961 in IL1RN gene, rs2228145 and rs4537545 in IL6R with schizophrenia have been observed. rs6676671 in IL10 was associated with early age of onset. Strong linkage disequilibrium was observed between analyzed polymorphisms in each gene, except of IL10RA. We observed that haplotypes composed of rs4537545 and rs2228145 in IL6R gene were associated with schizophrenia. Analyses with family history of schizophrenia, other psychiatric disorders and alcohol abuse/dependence did not show any positive findings. Further studies on larger groups along with correlation with circulating protein levels are needed.

Angiotensin converting enzyme activity is positively associated with IL-17a levels in patients with schizophrenia

Previous studies of our group showed increased plasmatic Angiotensin-I Converting Enzyme (ACE) activity in schizophrenia (SCZ) patients compared to healthy controls, which was also associated to poor cognitive functioning. The ACE main product angiotensin II (Ang-II) has pro-inflammatory properties. Activated immune-inflammatory responses in SCZ and their association with disease progression and cognitive impairments are also well-described. Therefore, we examined here the association of plasma ACE activity and inflammatory mediators in 33 SCZ patients and 92 healthy controls. Non-parametric correlations were used to investigate the association of the enzyme activity and the peripheral levels of immune inflammatory markers as interleukins, tumor necrosis factor (TNF-α), and interferon (IFN-γ). Although no significant correlations could be observed for ACE activity and measured cytokines levels in healthy controls, a significant positive correlation for ACE enzymatic activity and IL-17a levels was observed in SCZ patients. Correcting for gender did not change these results. Moreover, a significant association for ACE activity and IFN-γ levels was also observed. To our knowledge, this is the first study to show a significant association between higher ACE activity and the levels of cytokines, namely IL-17a and IFN-γ, in patients with SCZ.

Toxoplasma gondii-induced neuronal alterations

The zoonotic pathogen Toxoplasma gondii infects over 30% of the human population. The intracellular parasite can persist lifelong in the CNS within neurons modifying their function and structure, thus leading to specific behavioural changes of the host. In recent years, several in vitro studies and murine models have focused on the elucidation of these modifications. Furthermore, investigations of the human population have correlated Toxoplasma seropositivity with changes in neurological functions; however, the complex underlying mechanisms of the subtle behavioural alteration are still not fully understood. The parasites are able to induce direct modifications in the infected cells, for example by altering dopamine metabolism, by functionally silencing neurons as well as by hindering apoptosis. Moreover, indirect effects of the peripheral immune system and alterations of the immune status of the CNS, observed during chronic infection, might also contribute to changes in neuronal connectivity and synaptic plasticity. In this review, we will provide an overview and highlight recent advances, which describe changes in the neuronal function and morphology upon T. gondii infection.

Metabolic and inflammatory genes in schizophrenia

Energy metabolism and immunity are characterized as abnormal in schizophrenia. Because these two systems are highly coordinated, we measured expression of prototypic obesogenic and immunogenic genes in freshly harvested PBMC from controls and participants with schizophrenia. We report significant increases in PPARγ, SREBP1, IL-6 and TNFα, and decreases in PPARα and C/EPBα and mRNA levels from patients with schizophrenia, with additional BMI interactions, characterizing dysregulation of genes relating to metabolic-inflammation in schizophrenia.

A randomised double-blind placebo-controlled 12- week feasibility trial of methotrexate added to treatment as usual in early schizophrenia: study protocol for a randomised controlled trial

Background

Methotrexate is a commonly used anti-inflammatory and immunosuppressive drug. There is growing evidence that inflammatory processes are involved in the pathogenesis of schizophrenia. In our recent randomised double-blind placebo-controlled clinical trial in Pakistan and Brazil, the addition of minocycline (antibiotic and anti-inflammatory drug) for 1 year to treatment as usual reduced negative symptoms and improved some cognitive measures. A meta-analysis of cytokine changes in the peripheral blood has identified IL-2, IFN-gamma, TNF-alpha and soluble IL-2 receptor as trait markers of schizophrenia because their levels were elevated during acute exacerbations and reduced in remission. This suggests immune activation and an inflammatory syndrome in schizophrenia. Based on the evidence of the strong anti-inflammatory properties of methotrexate, we propose that low-dose methotrexate may be an effective therapy in early schizophrenia.

Methods/Design

This is a double-blind placebo-controlled study of methotrexate added to treatment as usual for patients suffering from schizophrenia, schizoaffective disorder, psychosis not otherwise specified or schizophreniform disorder. This will be with 72 patients, 36 in each arm over 3 months. There will be screening, randomisation and follow-up visits. Full clinical assessments will be carried out at baseline, 2, 4, 8 and 12 weeks. Social and cognitive assessments will be carried out at baseline and 12 weeks. Methotrexate will be given at a dose of 10 mgs orally once a week for a 3-month period.

Discussion

Evidence suggests inflammatory processes are involved in the pathogenesis of schizophrenia and anti-inflammatory treatments have shown to have some beneficial effects. Methotrexate is a known immunosuppressant and anti-inflammatory drug. The aim of this study is to establish the degree of improvement in positive and negative symptoms, as well as cognitive functioning with the addition of methotrexate to treatment as usual.

ClinicalTrials.gov identifier: NCT02074319 (24 February 2014).

Eicosanoids Derived From Arachidonic Acid and Their Family Prostaglandins and Cyclooxygenase in Psychiatric Disorders

Arachidonic acid (AA)-derived lipid mediators are called eicosanoids. Eicosanoids have emerged as key regulators of a wide variety of physiological responses and pathological processes, and control important cellular processes. AA can be converted into biologically active compounds by metabolism by cyclooxygenases (COX). Beneficial effect of COX-2 inhibitor celecoxib add-on therapy has been reported in early stage of schizophrenia. Moreover, add-on treatment of celecoxib attenuated refractory depression and bipolar depression. Further, the COX/prostaglandin E pathway play an important role in synaptic plasticity and may be included in pathophysiology in autism spectrum disorders (ASD). In this regard, plasma transferrin, which is an iron mediator related to eicosanoid signaling, may be related to social impairment of ASD. COX-2 is typically induced by inflammatory stimuli in the majority of tissues, and the only isoform responsible for propagating the inflammatory response. Thus, COX-2 inhibitors considered as the best target for Alzheimer's disease.

Decreased serum TNF-alpha levels in chronic schizophrenia patients on long-term antipsychotics: correlation with psychopathology and cognition

OBJECTIVE

A substantial body of evidence implicates TNF-alpha (TNFα) and TNFα-related signaling pathways in the pathophysiology of schizophrenia. The current study examined the relationship between TNFα serum levels and both psychopathological as well as cognitive symptoms in schizophrenia.

MATERIALS AND METHODS

Serum TNFα levels were assessed in 89 patients diagnosed with schizophrenia and compared to 43 healthy control subjects matched for age and gender. Schizophrenic symptomatology was assessed with the Positive and Negative Syndrome Scale (PANSS), and serum TNFα levels were measured by sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

TNFα levels were significantly lower in patients with chronic schizophrenia relative to healthy control subjects (p<0.01). Correlation analysis revealed a significant negative correlation between the TNFα levels and the PANSS total score (p<0.01). Additionally, TNFα levels were significantly negatively correlated with scores on general psychopathology (p<0.01), positive (p<0.05) and cognitive subscales (p<0.05). Stepwise multiple regression analysis identified TNFα levels as a significant predictor of scores on the general psychopathology subscale of the PANSS.

CONCLUSION

The significant relations observed in the current study between TNFα and the PANSS and its subscales suggest that immune disturbance may be involved in the psychopathology and cognitive deficits of schizophrenia.

Chronic lipopolysaccharide exposure induces cognitive dysfunction without affecting BDNF expression in the rat hippocampus

Previous studies have shown that lipopolysaccharide (LPS) has the potential to cause cognitive dysfunction. However, the underlying pathogenesis has yet to be fully elucidated. Increasing attention is being focused on infection in the central nervous system. Therefore, the present study aimed to investigate the behavioral performance of rats receiving intraperitoneal injections of LPS and to determine the expression levels of amyloid-β (Aβ), brain-derived neurotrophic factor (BDNF) and pro-inflammatory cytokines in the hippocampus. In total, 30 male Wistar rats were randomly divided into 3 groups (each n=10): Control and 3 and 7 day LPS administration groups. The rats were intraperitoneally injected with saline or LPS for 3 or 7 days. Following this, rats performed the Morris water maze test, in which the latency to the platform and proportion of time spent in the target quadrant were recorded. Rats were then sacrificed and the hippocampi were harvested for determination of interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), Aβ and BDNF expression levels. LPS administration for 3 and 7 days significantly increased the latency to the platform and decreased the proportion of time spent in the target quadrant compared with those in the control group, (P<0.05). Administration of LPS for 3 and 7 days induced statistically significant increases in the expression levels of IL-1β, IL-6 and TNF-α in the hippocampus, compared with those in the control group (P<0.05). Additionally, the administration of LPS for 7 days induced a statistically significant increase in the expression level of Aβ in the hippocampus, compared with that in the control group (P<0.05). However, the administration of LPS did not elicit a statistically significant change in the expression level of BDNF in the hippocampus, compared with that in the control group (P>0.05). The results indicate that LPS induces cognitive dysfunction, which is associated with increased expression levels of pro-inflammatory cytokines and Aβ, but does not affect the expression of BDNF in the hippocampus.

Cytomegalovirus seropositivity and serointensity are associated with hippocampal volume and verbal memory in schizophrenia and bipolar disorder

INTRODUCTION

Cytomegalovirus (CMV) is a member of the herpesviridae family that has a limbic and temporal gray matter tropism. It is usually latent in humans but has been associated with schizophrenia, bipolar disorder and cognitive deficits in some populations. Hippocampal decreased volume and dysfunction play a critical role in these cognitive deficits. We hypothesized that CMV seropositivity and serointensity would be associated with hippocampal volume and cognitive functioning in patients with schizophrenia or bipolar disorder.

METHODS

102 healthy controls, 118 patients with bipolar disorder and 69 patients with schizophrenia performed the California Verbal Learning Test (CVLT) and had blood samples drawn to assess CMV IgG levels. A subgroup of 52 healthy controls, 31 patients with bipolar disorder and 27 patients with schizophrenia underwent T1 MRI for hippocampal volumetry. We analyzed the association between CMV serointensity and seropositivity with hippocampal volume. We also explored the correlation between CMV serointensity and seropositivity and CVLT scores.

RESULTS

In both patient groups but not in controls, higher CMV serointensity was significantly associated with smaller right hippocampal volume. Further, in the group of patients with schizophrenia but not bipolar disorder, CMV serointensity was negatively correlated with CVLT scores.

CONCLUSION

CMV IgG titers are associated with decreased hippocampal volume and poorer episodic verbal memory in patients with schizophrenia or bipolar disorder. The mechanism of this association warrants further exploration.

Is there an association between peripheral immune markers and structural/functional neuroimaging findings?

OBJECTIVES

There is mounting evidence that inflammatory processes play a key role in emotional as well as cognitive dysfunctions. In this context, research employing magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MR spectroscopy) suggests a possible link between structural/functional anomalies in the brain and an increase of circulating inflammation markers. The present paper reviews this research, with particular focus on major depressive disorder (MDD), cognitive impairment in older adults, Alzheimer's disease (AD) and schizophrenia.

RESULTS

In MDD, cognitive impairment and AD, inflammatory processes have been found to be associated with both structural and functional anomalies, perhaps under the influence of environmental stress. Not enough research can suggest similar considerations in schizophrenia, although studies in mice and non-human primates support the belief that inflammatory responses generated during pregnancy can affect brain development and contribute to the etiology of schizophrenia.

CONCLUSIONS

The present review suggests a link between inflammatory processes and MRI detected anomalies in the brain of individuals with MDD, older adults with cognitive impairment as well as of individuals with AD and schizophrenia.

Glycogen synthase kinase-3 inhibitors: Rescuers of cognitive impairments

Impairment of cognitive processes is a devastating outcome of many diseases, injuries, and drugs affecting the central nervous system (CNS). Most often, very little can be done by available therapeutic interventions to improve cognitive functions. Here we review evidence that inhibition of glycogen synthase kinase-3 (GSK3) ameliorates cognitive deficits in a wide variety of animal models of CNS diseases, including Alzheimer's disease, Fragile X syndrome, Down syndrome, Parkinson's disease, spinocerebellar ataxia type 1, traumatic brain injury, and others. GSK3 inhibitors also improve cognition following impairments caused by therapeutic interventions, such as cranial irradiation for brain tumors. These findings demonstrate that GSK3 inhibitors are able to ameliorate cognitive impairments caused by a diverse array of diseases, injury, and treatments. The improvements in impaired cognition instilled by administration of GSK3 inhibitors appear to involve a variety of different mechanisms, such as supporting long-term potentiation and diminishing long-term depression, promotion of neurogenesis, reduction of inflammation, and increasing a number of neuroprotective mechanisms. The potential for GSK3 inhibitors to repair cognitive deficits associated with many conditions warrants further investigation of their potential for therapeutic interventions, particularly considering the current dearth of treatments available to reduce loss of cognitive functions.

First manic episode in a patient with breast cancer

Mental disorders occur in as much as 50% of patients with cancer, impairing the oncologic prognosis and quality of life. The diagnostic investigation and treatment planning of this comorbidity impose a clinical challenge once complications related to the neoplasm, such as brain metastasis and paraneoplastic syndromes, must be excluded. In addition, psychotropic medications may interfere with oncologic treatment. We report the case of a 39-year-old female patient who presented with a first episode of psychotic mania after having been recently diagnosed with breast cancer. Also, we present a literature review of this comorbidity and point out a possible pathophysiological link between the two diseases.

Do sleep abnormalities and misaligned sleep/circadian rhythm patterns represent early clinical characteristics for developing psychosis in high risk populations?

Sleep architecture changes, such as slow-wave sleep (SWS) percentage variations and reductions in latency and density of rapid eye movement (REM), are found in most patients with schizophrenia and are considered to be an important part of the pathophysiology of the disorder. In addition to these sleep parameters changes, disruptions in sleep homeostasis and the sleep/circadian rhythm also occur in these patients. Sleep/circadian rhythm abnormalities negatively affect neocortical plasticity and cognition and often precede the diagnosis of the illness. Thus, it has been suggested that the sleep/circadian rhythm might be involved in the pathophysiology of psychosis. Recent advances in the identification of individuals at a high risk for developing schizophrenia allow us to investigate several neurobiological processes involved in the development of psychosis. In this article, we review the current evidence of the effects of sleep parameter abnormalities, disruptions in sleep homeostasis and misalignments of sleep circadian rhythm on the early stages of schizophrenia. In addition, we discuss the preliminary evidence of sleep and circadian rhythm abnormalities during the prodromal stages of psychosis and propose that these abnormalities can be explored as potential predictors, as an adjunct to clinical diagnosis, of developing a psychotic disorder in at risk populations.

Autoantibodies and the immune hypothesis in psychotic brain diseases: challenges and perspectives

The pathophysiology of psychosis is poorly understood, with both the cognitive and cellular changes of the disease process remaining mysterious. There is a growing body of evidence that points to dysfunction of the immune system in a subgroup of patients with psychosis. Recently, autoantibodies directed against neuronal cell surface targets have been identified in a range of syndromes that feature psychosis. Of interest is the detection of autoantibodies in patients whose presentations are purely psychiatric, such as those suffering from schizophrenia. Autoantibodies have been identified in a minority of patients, suggesting that antibody-associated mechanisms of psychiatric disease likely only account for a subgroup of cases. Recent work has been based on the application of cell-based assays-a paradigm whose strength lies in the expression of putative antigens in their natural conformation on the surface of live cells. The responsiveness of some of these newly described clinical syndromes to immune therapy supports the hypothesis that antibody-associated mechanisms play a role in the pathogenesis of psychotic disease. However, further investigation is required to establish the scope and significance of antibody pathology in psychosis. The identification of a subgroup of patients with antibody-mediated disease would promise more effective approaches to the treatment of these high-morbidity conditions.

Interleukin-6-induced S100B secretion is inhibited by haloperidol and risperidone

Although inflammation may be a physiological defense process, imbalanced neuroinflammation has been associated with the pathophysiology of brain disorders, including major depression and schizophrenia. Activated glia releases a variety of pro-inflammatory cytokines that contribute to neuronal dysfunction. Elevated levels of S100B, a glia derived protein, have been observed in the serum and CSF of schizophrenic patients suggesting a glial role in the disease. We evaluated whether S100B secretion (in C6 glioma cells and hippocampal slices in Wistar rats) could be directly modulated by the main inflammatory cytokines (IL-1β, TNF-α, IL-6 and IL-8) altered in schizophrenia, as well as the possible involvement of mitogen-activated protein kinase (MAPK) pathways in these responses. We also investigated the effects of typical and atypical antipsychotic drugs on glial cytokine-induced S100B release. Our results suggest that S100B secretion is increased by pro-inflammatory cytokines via MAPK and that oxidative stress may be a component of this modulation. These results reinforce the idea that the S100B protein is involved in the inflammatory response observed in many brain diseases, including schizophrenia. Moreover the antipsychotics, haloperidol and risperidone, were able to inhibit the secretion of S100B following IL-6 stimulation in C6 glioma cells.

Ondansetron and simvastatin added to treatment as usual in patients with schizophrenia: study protocol for a randomized controlled trial

BACKGROUND

Negative symptoms and cognitive deficits are two partially-related features of schizophrenia which have a major negative impact on social function and objective quality of life. Standard drug treatments have little impact on either. There is some evidence that anti-inflammatory treatment may have beneficial effects in schizophrenia and major depression. Statins are cholesterol-lowering agents that have been found to be anti-inflammatory agents and are also known to decrease C-reactive protein (CRP). Ondansetron is a serotonin (5-HT3) receptor antagonist widely used to prevent nausea and vomiting in patients receiving chemotherapy for cancer. Small studies have suggested that ondansetron is effective as an adjunct drug in improving the symptoms of schizophrenia.

METHODS/DESIGN

This is a two center, six-month, double-blind placebo controlled, factorial design study of ondansetron and/or simvastatin added to treatment as usual for patients suffering from schizophrenia, schizoaffective disorder, psychosis not otherwise specified or schizophreniform disorder. This will be a 2 × 2 design, with 54 patients in each cell, giving a total of 216 patients over three years. There will be a screening, a randomization and seven follow-up visits. Full clinical and neurocognitive assessments will be carried out at baseline (randomization), 14 weeks and at 26 weeks, while the positive and negative syndrome scale (PANSS), pill count and side effects checklist will be carried out at every visit. Simvastatin will be started at 20 mg once daily (OD), this will be increased to 40 mg after four weeks. Ondansetron will be administered in an 8 mg dose.

DISCUSSION

Anti-inflammatory treatments have been shown to have some beneficial effects in schizophrenia. Both simvastatin and ondansetron provide some evidence of a reduction in symptoms compared to treatment as usual. The aim of this study is to establish the degree of improvement in negative symptoms with the addition of ondansetron and/or simvastatin to treatment as usual.

TRIAL REGISTRATION

[corrected] ClinicalTrials.gov NCT01602029.

Circulating levels of sTNFR1 as a marker of severe clinical course in schizophrenia

BACKGROUND

Schizophrenia (SZ) has been associated with an imbalance in the inflammatory cytokine TNF-α. The objectives of this study were to compare TNF-α and its soluble receptors' serum levels in individuals with SZ with the levels found in a group of healthy volunteers and to investigate the possible association between these biomarkers and the dimensions and severity of symptoms, clinical outcomes and response to treatment in patients with SZ.

METHODS

Fifty-four chronically medicated SZ outpatients and 118 healthy controls were included in the study. TNF-α levels were measured by Cytometric Bead Assay (CBA), and serum levels of soluble tumor necrosis factor receptor 1 (sTNFR1) and soluble tumor necrosis factor receptor 2 (sTNFR2) were measured by ELISA.

RESULTS

sTNFR1 and sTNFR2 were significantly elevated in patients with SZ as compared to the healthy control group. In the group of individuals with SZ, the levels of both types of soluble TNF receptors showed a negative correlation with global functioning. sTNFR1 levels were higher in the treatment-resistant patients as compared to the non-treatment-resistant patients and the controls. sTNFR1 levels were also heightened in patients with SZ and concomitant depression.

CONCLUSION

Our findings reinforce that SZ is associated with an inflammatory profile and suggest that sTNFR1 is a marker of a treatment-resistance and severe clinical course in SZ.

The "selfish brain" hypothesis for metabolic abnormalities in bipolar disorder and schizophrenia

Metabolic abnormalities are frequent in patients with schizophrenia and bipolar disorder (BD), leading to a high prevalence of diabetes and metabolic syndrome in this population. Moreover, mortality rates among patients are higher than in the general population, especially due to cardiovascular diseases. Several neurobiological systems involved in energy metabolism have been shown to be altered in both illnesses; however, the cause of metabolic abnormalities and how they relate to schizophrenia and BD pathophysiology are still largely unknown. The "selfish brain" theory is a recent paradigm postulating that, in order to maintain its own energy supply stable, the brain modulates energy metabolism in the periphery by regulation of both allocation and intake of nutrients. We hypothesize that the metabolic alterations observed in these disorders are a result of an inefficient regulation of the brain energy supply and its compensatory mechanisms. The selfish brain theory can also expand our understanding of stress adaptation and neuroprogression in schizophrenia and BD, and, overall, can have important clinical implications for both illnesses.