Transcriptome profiling as a biological marker for bipolar disorder sub-phenotypes.

PURPOSE: Bipolar affective disorder (BP) causes major functional impairment and reduced quality of life not only for patients, but also for many close relatives. We aimed to investigate mRNA levels in BP patients to find differentially expressed genes linked to specific clinical course variants; assuming that several gene expression alterations might indicate vulnerability pathways for specific course and severity of the disease. MATERIALS: We searched for up- and down-regulated genes comparing patients with diagnosis of BP type I (BPI) vs type II (BPII), history of suicide attempts, psychotic symptoms, predominance of manic/hypomanic episodes, and history of numerous episodes and comorbidity of substance use disorders or anxiety disorders. RNA was extracted from peripheral blood mononuclear cells and analyzed with use of microarray slides. RESULTS: Differentially expressed genes (DEGs) were found in all disease characteristics compared. The lowest number of DEGs were revealed when comparing BPI and BPII patients (18 genes), and the highest number when comparing patients with and without psychotic symptoms (3223 genes). Down-regulated genes identified here with the use of the DAVID database were among others linked to cell migration, defense response, and inflammatory response. CONCLUSIONS: The most specific transcriptome profile was revealed in BP with psychotic symptoms. Differentially expressed genes in this variant include, among others, genes involved in inflammatory and immune processes. It might suggest the overlap of biological background between BP with a history of psychotic features and schizophrenia.

Plasma biomarkers in adolescents with schizophrenia-spectrum disorder.

AIM: Schizophrenia onset in the developmental age has a strong neurodevelopmental burden and is associated with a poorer prognosis. The approach to diagnosis is still based on symptomatic description without objective validation. In this study, we aimed to compare the peripheral blood levels of hypothesized biomarker proteins: brain-derived neurotrophic factor (BDNF), proBDNF, p75 neurotrophin receptor (p75NTR ) and S100B between early-onset schizophrenia-spectrum adolescents (n = 45) and healthy controls (n = 34). METHODS: Clinical assessment of the participants encompassed symptomatic description with the use of structured interviews and executive function objective measurement. Plasma levels of BDNF protein were significantly lower in schizophrenia patients than in controls both at admission (p = .003) and 6-8 weeks follow-up (p = .007). RESULTS: We observed significant correlations between BDNF, proBDNF and p75NTR levels and positive and negative symptoms scale (PANSS) scores, p75NTR and S100B levels and suicidal parameters, as well as a correlation of BDNF plasma level with the risky decision-making style in Iowa Gambling Task (IGT). CONCLUSIONS: The results indicate a potential value of studied proteins as a biomarker in the diagnosis and monitoring of the disease's course.

Differential expression profile between amygdala and blood during chronic lithium treatment in a rat model of depression - a pilot study.

Lithium is a mood stabilizer widely used in the pharmacotherapy of bipolar disorder and treatment­resistant depression. Taking into account dysregulated inflammatory activity in depression and the immunomodulatory role of lithium, we hypothesized that genes associated with inflammatory responses may be potential biomarkers of lithium action. We aimed to compare gene expression changes between the brain and the periphery after chronic lithium administration in an animal model of depression. Depressive behavior was induced by chronic mild stress protocol for 4 weeks. After 2 weeks, rats started to receive lithium (study group) or water (reference group). The control group were rats not exposed to stress. Amygdala, hippocampus, frontal cortex and peripheral blood were analyzed using whole transcriptome expression microarrays. Changes were confirmed with qPCR and ELISA assay. After 2 weeks of lithium administration, we observed significant changes in gene expression between amygdala and peripheral blood. Logistic regression analysis determined Alox15 expression as a predictor of lithium status, as its expression was tissue­specific and increased in amygdala and decreased in blood. Analysis of serum ALOX15 protein revealed its upregulation after two­week lithium administration. Our study suggests that lithium may have therapeutic potential in depressive behaviors. These results indicate immunomodulatory effect of lithium and that Alox15 may be a new potential marker of chronic lithium treatment.

Glycine transporters in schizophrenia. A new hope or informational noise? / Transportery glicynowe w schizofrenii. Nowa nadzieja czy szum informacyjny?

Currently, we observe a huge number of publications describing the role of glycine transporter (GlyT1) inhibitors in schizophrenia treatment. The concept of application for these drugs derives from the glutamatergic theory of schizophrenia. This theory explains psychotic disturbances as the consequence of NMDA receptor functioning defect. The role of the mentioned receptor depends mostly on the presence of cofactors. One such cofactor is the simplest aminoacid, glycine. This amino acid affects the glycine-binding site, located on the NR1 subunit of NMDAR and enables activation of the receptor. Substances enhancing the access of glycine to the receptor could hypothetically improve neuroplasticity. Higher efficacy of these neuroplastic processes may protect from cognitive deterioration and negative symptoms in the course of schizophrenia. In this article we present a systematic review of current literature on the topic of GlyT1 inhibitors in schizophrenia treatment (the state of literature as of November 2019). Firstly, we described the preclinical reasons for glycine enhancement use. Next, we used CINAHL, EMBASE, EMCARE, Medline, PsycINFO, PubMed and Google Scholar databases to extract and analyze evidence from clinical trials. GlyT1 inhibitors seem to have a potential in searching for novel substances in the treatment of negative symptoms, but their capacity to reduce cognitive deficits is not evidenced. So far, the clinical efficacy of several substances was proven, including N-methylglycine (sarcosine), bitopertin and derivatives obtained with chemical synthesis. Some of these substances demonstrate a beneficial clinical effect, but the number of published reports in this area is disproportionate to the value of evidence.

Disembodied Language in Early-Onset Schizophrenia.

A recent view on schizophrenia phenomenology underlines the impaired relations between the mind and the body. An aberrant feeling of ipseity may be the real source of suffering of the patients from psychosis and impacts general symptomatology. The disturbed connection between thinking processes and environmental stimuli may lead to language disembodiment. In the study, we aimed to experimentally test the presence of disembodied language and investigate its association with symptoms of psychosis in adolescents diagnosed with early-onset schizophrenia spectrum disorders. Assessment of language embodiment was conducted using the Zabór Verbal Task (ZVT) with concurrent linguistic and clinical assessment using the Thought, Language, and Communication Scale (TLCS) and Positive and Negative Symptoms Scale (PANSS). The study group of patients (n = 31) aged 11-18 years, with the diagnosis of schizophrenia spectrum according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and the International Classification of Diseases (ICD-10) criteria, was compared with a sex- and age-matched healthy control sample (n = 31). Patients with psychosis made more errors in ZVT than healthy controls (p = 0.01) and this parameter did not improve after 6-8 weeks of standard treatment (p = 0.55). A higher number of errors in ZVT were associated with the presence of auditory hallucinations (odds ratio [OR] 1.14; 95% CI 1.02-1.26). ZVT errors coincided with perception disorders, alternatively to the TLCS scores where we observed association with abnormal beliefs. The results of these preliminary studies indicate the value of the phenomenological approach in the diagnosis of schizophrenia spectrum and suggest a potential involvement of language disembodiment in symptomatology.

Genetic association study reveals impact of interleukin 10 polymorphisms on cognitive functions in schizophrenia.

AIM: Cognitive deficits are the core factors impacting quality of life among patients diagnosed with schizophrenia. Effective method of treatment for this domain of symptoms remains lacking. Recent evidence suggests the link between impaired cognition and aberrant inflammatory response. Severity of symptoms might be linked to individual genetic predispositions and single-nucleotide polymorphisms (SNPs) in genes encoding interleukins and their receptors. Current genetic association studies include anti-inflammatory interleukins, such as IL10. Functional polymorphisms of IL10 (rs1800871, rs18008729) have been indicated to affect information processing in schizophrenia. MATERIALS AND METHODS: In this study, we analyzed the potential impact of 27 functional SNPs in 8 cytokine genes on cognitive parameters measured by Wisconsin card-sorting test (WCST) in schizophrenia group (n = 150) and healthy controls (n = 152). RESULTS: We found significant associations of two functional polymorphisms of IL10 (rs1800871, rs1800872) and WCST results. Allele A carriers in rs1800871 performed significantly better in Percent of Conceptual Level Responses (CLR%). Allele A carriers in rs1800871 and allele T carriers in rs1800872 obtained better results in Completed Categories (CC). The impact of illness duration was observed, with better performance of recent-onset patients. CONCLUSIONS: Results of this study indicate that genetic variants of inflammatory response are associated with cognitive deficits in schizophrenia. The role of cytokines in schizophrenia need to be investigated in the aspect of pro-/anti-inflammatory imbalance. Altered inflammatory response promote chronic mild inflammation in the brain and aberrant synaptic plasticity.

Impulsivity as a Risk Factor for Suicide in Bipolar Disorder.

The accurate assessment of suicide risk in psychiatric, especially affective disorder diagnosed patients, remains a crucial clinical need. In this study, we applied temperament and character inventory (TCI), Barratt impulsiveness scale 11 (BIS-11), PEBL simple reaction time (SRT) test, continuous performance task (CPT), and Iowa gambling task (IGT) to seek for variables linked with attempted suicide in bipolar affective disorder group (n = 60; attempters n = 17). The main findings were: strong correlations between self-report tool scores and objective parameters in CPT; the difference between attempters and non-attempters was found in the number of correctly responded trials in IGT; only one parameter differed between attempters and non-attempters in BPI diagnosis; and no significant differences between suicide attempters and non-attempters in TCI, BIS-11, and SRT were found. These justify the conclusion that impulsivity itself is not a strong predictor, and used as a single variable might not be sufficient to indicate the high suicide risk group among bipolar patients.

Differences in the Clinical Picture in Women with a Depressive Episode in the Course of Unipolar and Bipolar Disorder.

Due to current depression prevalence, it is crucial to make the correct diagnosis as soon as possible. The study aimed to identify commonly available, easy to apply, and quick to interpret tools allowing for a differential diagnosis between unipolar and bipolar disorder. The study group includes women with long duration of unipolar (UP, N = 34) and bipolar (BP, N = 43) affective disorder. The diagnosis was established according to the DSM criteria using SCID questionnaire. Additional questionnaires were used to differentiate between UP and BP. BP patients had an earlier age of onset, were hospitalized more times, and more often had a family history of psychiatric disorders than UP (p-value < 0.05). Moreover, BP achieved a higher impulsiveness score and more frequently had experienced severe problems with close individuals. To our knowledge, this is the first publication presenting results of numerous questionnaires applied simultaneously in patients on clinical group. Several of them suggest the direction of clinical assessment, such as: the age of onset, family psychiatric burdens, history of stressful life events, learning problems, social and job relations. Further studies are necessary to confirm the utility of this approach.

Transcriptome Changes in Three Brain Regions during Chronic Lithium Administration in the Rat Models of Mania and Depression.

Lithium has been the most important mood stabilizer used for the treatment of bipolar disorder and prophylaxis of manic and depressive episodes. Despite long use in clinical practice, the exact molecular mechanisms of lithium are still not well identified. Previous experimental studies produced inconsistent results due to different duration of lithium treatment and using animals without manic-like or depressive-like symptoms. Therefore, we aimed to analyze the gene expression profile in three brain regions (amygdala, frontal cortex and hippocampus) in the rat model of mania and depression during chronic lithium administration (2 and 4 weeks). Behavioral changes were verified by the forced swim test, open field test and elevated maze test. After the experiment, nucleic acid was extracted from the frontal cortex, hippocampus and amygdala. Gene expression profile was done using SurePrint G3 Rat Gene Expression whole transcriptome microarrays. Data were analyzed using Gene Spring 14.9 software. We found that chronic lithium treatment significantly influenced gene expression profile in both mania and depression models. In manic rats, chronic lithium treatment significantly influenced the expression of the genes enriched in olfactory and taste transduction pathway and long non-coding RNAs in all three brain regions. We report here for the first time that genes regulating olfactory and taste receptor pathways and long non-coding RNAs may be targeted by chronic lithium treatment in the animal model of mania.

Genes involved in glucocorticoid receptor signalling affect susceptibility to mood disorders.

OBJECTIVES: In mood disorders chronic stress contributes to decreased glucocorticoid receptor signalling in the brain and resistance in the periphery. We hypothesised that aberrant glucocorticoid receptor function may result from genetic predisposition and that decreased GR signalling in the brain correlates with the expression of genes regulating GR complex formation. METHODS: We performed the association analysis of 698 patients: 490 patients with bipolar disorder and 208 patients with major depressive disorder and 564 control subjects. We genotyped 11 variants using TaqMan assays. Gene expression in the brain tissue was done in male Wistar rats after chronic mild stress protocol. The SRSF5 serum concentration was performed using ELISA. Data were analysed in Statistica and GraphPad. RESULTS: We found an association of STIP1 and SRSF5 variants with major depressive disorder and BAG1 variant with bipolar disorder. Gene expression analysis in a rat model of depression confirmed significant changes in the expression of SRSF5, BAG1, and FKBP4 in the brain. For SRSF5, we observed significantly increased expression in the serum of depressed females and male rats exposed to chronic stress. CONCLUSIONS: Our results indicate the involvement of genes associated with GR function, SRSF5, BAG1, and FKBP4 with susceptibility to mood disorders.

Mambalgins, the Venom-origin Peptides as a Potentially Novel Group of Analgesics: Mini Review.

BACKGROUND: Despite a wide variety of current analgesia regimens, chronic pain is an incredibly difficult condition to treat. Its pathophysiology, initiation, development and course involve a range of different receptors and transmitters. The acid-sensing ion channels (ASICs) are being attributed to an increasingly larger significance in pain aetiology. Over the last few years, the mechanism of ASICs action, influence of their antagonists/agonists and clinical applications have been well described. However, the importance of this protein is significantly larger, not only from the perspective of pain management, but also in psychiatry of addiction or fear. Recently discovered peptides from three-finger toxin group, called mambalgins (isolated from Dendroaspis polylepis polylepsis) exhibit potent analgesic mechanisms of action on ASICs in animal model. AIMS & METHODS: The article reviews current knowledge in the field of mambalgins and assesses their potential analgesic application, based on the recent experimental evidence. RESULTS: The mambalgins seem to decrease the intensity of the inflammatory, neuropathic and mechanic pain. This has been demonstrated in animal studies of different pain models, including carrageenan- induced inflammatory pain, chronic constrictive injury-induced neuropathic pain and thermal pain. The mechanism of mambalgin action is not clearly defined, but it is suspected that they bind directly to the pH-sensitive region of the ASIC. CONCLUSION: In this short review, we attempted to summarise the current knowledge about mambalgins and their potential applications as a new substance in searching for the ideal analgesia without common side effects of the other drug groups.