High concentrations of serum interleukin-6 and interleukin-8 in patients with bipolar disorder

Serum Levels of Zinc, Albumin, Interleukin-6 and CRP in Patients with Unipolar and Bipolar Depression: Cross Sectional Study

Unipolar (UD) and bipolar depression (BDD) show a high degree of similarity in clinical presentations, which complicates the differential diagnosis of these disorders. The aim of this study was to investigate the serum levels of interleukin 6 (IL-6), C-reactive protein (CRP), albumin (Alb), and zinc (Zn) in patients with UD, BDD, and healthy controls (HC). A total of 211 samples were collected: 131 patient samples (65 UD and 68 BDD) and 80 HC. The Montgomery-Asberg Depression Rating Scale (MADRS), along with the Hamilton Depression Rating Scale (HAMD-17), were administered to patient groups to evaluate symptoms. A cross-sectional study was performed to analyse the serum levels of IL-6, CRP, albumin, and zinc. The concentration of CRP was determined using the immunoturbidimetry method, zinc using the colorimetric method, and albumin using the colorimetric method with bromocresol green on the Alinity c device. IL-6 cytokine concentration in serum samples was ascertained using a commercial enzyme immunoassay, ELISA. We found no significant differences in serum concentrations of zinc, albumin, CRP, and IL-6 between the groups of patients with unipolar and bipolar depression. There was a significant statistical difference (p < 0.001) between serum levels of all investigated parameters in both groups of depressed patients in comparison with HC. Furthermore, correlations with specific items on HAMD-17; (namely, hypochondrias, work and activities, somatic symptoms-general, and weight loss) and on MADRS (concentration difficulties, lassitude) were observed in both patient groups. These findings confirm the presence of low-grade inflammation in depression, thus adding better insight into the inflammation hypothesis directed to explain the aetiology of depressive disorders. Our results do not indicate potential biomarkers for distinguishing between unipolar and bipolar depression.

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

Magnesium-lithium thin films for neurological applications-An in vitro investigation of glial cytocompatibility and neuroinflammatory response

Lithium (Li), a widely used drug for bipolar disorder management, is associated with many side effects due to systemic exposure. The localized delivery of lithium through implants could be an approach to overcome this challenge, for which biodegradable magnesium (Mg)-based materials are a promising choice. In this study, we focus on Mg-Li thin film alloys as potential Li-releasing implants. Therefore, we investigated the in vitro short-term corrosion behavior and cytocompatibility of two alloys, Mg-1.6wt%Li and Mg-9.5wt%Li. As glial cells are the key players of foreign body responses to implants, we used human glial cell lines for cytocompatibility studies, and a murine brain slice model for a more holistic view at the neuroinflammatory response. We found that Mg-1.6wt%Li corrodes approximately six times slower than Mg-9.5wt%Li. Microscopic analysis showed that the material surface (Mg-1.6wt%Li) is suitable for cell adhesion. The cytocompatibility test with Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts revealed that both cell types proliferated well up to 10 mM Mg concentration, irrespective of the Li concentration. In the murine brain slice model, Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts did not provoke a significant upregulation of glial inflammatory/ reactivity markers (IL-1β, IL-6, FN1, TNC) after 24 h of exposure. Furthermore, the gene expression of IL-1β (up to 3-fold) and IL-6 (up to 16-fold) were significantly downregulated after 96 h, and IL-6 downregulation showed a Li concentration dependency. Together, these results indicate the acute cytocompatibility of two Mg-Li thin film alloys and provide basis for future studies to explore promising applications of the material. STATEMENT OF SIGNIFICANCE: We propose the idea of lithium delivery to the brain via biodegradable implants to reduce systemic side effects of lithium for bipolar disorder therapy and other neurological applications. This is the first in vitro study investigating Mg-xLi thin film degradation under physiological conditions and its influence on cellular responses such as proliferation, viability, morphology and inflammation. Utilizing human brain-derived cell lines, we showed that the material surface of such a thin film alloy is suitable for normal cell attachment. Using murine brain slices, which comprise a multicellular network, we demonstrated that the material extracts did not elicit a pro-inflammatory response. These results substantiate that degradable Mg-Li materials are biocompatible and support the further investigation of their potential as neurological implants.

Transcriptional and functional effects of lithium in bipolar disorder iPSC-derived cortical spheroids

Lithium (Li) is recommended for long-term treatment of bipolar disorder (BD). However, its mechanism of action is still poorly understood. Induced pluripotent stem cell (iPSC)-derived brain organoids have emerged as a powerful tool for modeling BD-related disease mechanisms. We studied the effects of 1 mM Li treatment for 1 month in iPSC-derived human cortical spheroids (hCS) from 10 healthy controls (CTRL) and 11 BD patients (6 Li-responders, Li-R, and 5 Li non-treated, Li-N). At day 180 of differentiation, BD hCS showed smaller size, reduced proportion of neurons, decreased neuronal excitability and reduced neural network activity compared to CTRL hCS. Li rescued excitability of BD hCS neurons by exerting an opposite effect in the two diagnostic groups, increasing excitability in BD hCS and decreasing it in CTRL hCS. We identified 132 Li-associated differentially expressed genes (DEGs), which were overrepresented in sodium ion homeostasis and kidney-related pathways. Moreover, Li regulated secretion of pro-inflammatory cytokines and increased mitochondrial reserve capacity in BD hCS. Through long-term Li treatment of a human 3D brain model, this study partly elucidates the functional and transcriptional mechanisms underlying the clinical effects of Li, such as rescue of neuronal excitability and neuroprotection. Our results also underscore the substantial influence of treatment duration in Li studies. Lastly, this study illustrates the potential of patient iPSC-derived 3D brain models for precision medicine in psychiatry.

Association of markers of inflammation on attention and neurobehavioral outcomes in survivors of childhood acute lymphoblastic leukemia

Background

Survivors of childhood acute lymphoblastic leukemia (ALL) are at-risk of developing cognitive impairment and neurobehavioral symptoms. Inflammation induced by a compromised health status during cancer survivorship is proposed as a pathophysiological mechanism underlying cognitive impairment in cancer survivors.

Objectives

To evaluate the associations of biomarkers of inflammation with attention and neurobehavioral outcomes in survivors of childhood ALL, and to identify clinical factors associated with biomarkers of inflammation in this cohort.

Methods

We recruited patients who were diagnosed with ALL at ≤ 18 years old and were currently ≥5 years post-cancer diagnosis. The study outcomes were attention (Conners Continuous Performance Test) and self-reported behavioral symptoms (Adult Self-Report [ASR] checklist). Using a commercial screening kit, survivors' plasma (5ml) was assayed for 17 cytokines/chemokine cell-signaling molecules that are associated with neurodegenerative diseases. The final panel of the targeted markers included interleukin (IL)-8, IL-13, interferon-gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1β, and tumor necrosis factor-α. Biomarker levels were rank-ordered into tertiles based on the sample distribution. Multivariable general linear modeling was used to test for associations between biomarkers and study outcomes in the overall cohort and stratified by gender.

Results

This study included 102 survivors (55.9% males, mean[SD] age 26.2[5.9] years; 19.3[7.1] years post-diagnosis). Survivors within top tertiles of IFN-γ (Estimate =6.74, SE=2.26; P=0.0037) and IL-13 (Estimate =5.10, SE=2.27; P=0.027) demonstrated more inattentiveness. Adjusting for age, gender and treatment, more self-reported thought (Estimate=3.53, SE=1.78; P=0.050) and internalizing problems (Estimate =6.52, SE=2.91; P=0.027) correlated with higher IL-8. Higher levels of IL-13 (RR = 4.58, 95% CI: 1.01-11.10) and TNF-α (RR = 1.44, 95% CI: 1.03-4.07) were observed in survivors had developed chronic health conditions (n=26, 25.5%). The stratified analysis showed that association of IFN-γ with attention was stronger in male survivors than in female survivors.

Conclusion

Inflammation due to cancer-related late effects may potentially be mechanistic mediators of neurobehavioral problems in pediatric ALL survivors. Markers of inflammation can potentially be applied to assess or monitor the effectiveness of interventions, particularly behavioral interventions, in improving cognitive outcomes in survivors. Future work includes understanding the underlying gender-specific pathophysiology behind functional outcomes in the population.

Comparison of oxidative stress parameters, thiol-disulfide homeostasis, and pro-inflammatory cytokines levels in patients with bipolar disorder and their first-degree relatives

BACKGROUND

In this study, we aimed to compare the oxidative stress parameters, thiol-disulfide homeostasis, and plasma pro-inflammatory cytokines levels of patients with bipolar disorder (BD), BD patients' first-degree relatives (FDRs), and the healthy controls (HCs).

METHODS

Thirty-five patients with BD, 35 FDRs of BD, and 35 healthy controls (HCs) were included. The individuals' ages varied from 28 to 58, and the groups were well-matched in terms of age and gender. The total thiol (TT), native thiol (NT), disulfide (DIS), total oxidant status (TOS), total antioxidant status (TAS), IL-1β, IL-6, and TNF-α concentrations were measured from serum samples. The oxidative stress index (OSI) was calculated using mathematical formulas.

RESULTS

TOS was significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons). OSI, DIS, oxidized thiol, and the ratio of thiol oxidation-reduction levels were significantly higher in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). TAS, TT, NT, and reduced thiol levels were significantly lower in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). IL-1β, IL-6, and TNF-α were significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons).

LIMITATIONS

Small sample size.

CONCLUSIONS

Early diagnosis is important for treating of bipolar disorder. TT, NT, DIS, TOS, TAS, OSI, IL1-β, IL-6, and TNF-α can be used as potential biomarkers in the early diagnosis and intervention of BD. Furthermore, oxidative/antioxidative markers and plasma pro-inflammatory cytokine parameters may guide the determination of the disease's activity and response to treatment.

Clinical characteristics of bipolar 1 disorder in relation to interleukin-6: a cross-sectional study among Egyptian patients

Background

Strong evidence in the literature points to the role of pro-inflammatory cytokines in bipolar disorder (BD) pathophysiology. Interleukin-6 (IL-6) is a pro and anti-inflammatory cytokine that was repeatedly found higher in bipolar patients than in healthy controls. However, studies on the phasic differences of IL-6 in bipolar type I (BP-I) were limited. This study aims to explore the phasic differences of serum IL-6 levels in BP-I during euthymia, depression, and mania and their association with the disease’s clinical characteristics in a sample of Egyptian BP-I patients. Thirty currently euthymic, 24 currently depressed, 29 currently manic BP-I patients, and 20 healthy subjects were recruited. Serum IL-6 levels were compared among BP-I groups and then between each group and a group of 20 healthy controls. Serum IL-6 levels (pg/ml) were measured with a sandwich enzyme-linked immunosorbent assay (ELISA). Depression and mania symptoms were assessed using the Hamilton Depression Rating Scale (HDRS) and the Young Mania Rating Scale (YMRS), respectively. Clinical characteristics were evaluated through a semi-structured clinical psychiatric interview, and cognitive status was tested using the Montreal Cognitive Assessment (MoCA).

Results

Serum IL-6 levels were significantly higher in each bipolar phase than in healthy subjects. In the BP-I patients, IL-6 levels were lower in patients with a current manic episode than in patients with a current depressive episode (P < 0.05) or who were currently euthymic (P < 0.001). Moreover, IL-6 levels correlated inversely with the YMRS score (rs =  − 0.29; P < 0.05). Compared to patients without psychotic features, patients with psychotic features had decreased serum IL-6. Moreover, IL-6 levels were lower in inpatients compared to outpatients.

Conclusions

BP-I disorder is associated with an inflammatory state. The decreased levels of IL-6 during manic episodes, affective episodes with psychotic features, and their inverse correlation with the severity of mania symptoms indicate a possible anti-inflammatory role of IL-6 in mania and psychotic symptoms pathogenesis.

Dopamine, Immunity, and Disease

The neurotransmitter dopamine is a key factor in central nervous system (CNS) function, regulating many processes including reward, movement, and cognition. Dopamine also regulates critical functions in peripheral organs, such as blood pressure, renal activity, and intestinal motility. Beyond these functions, a growing body of evidence indicates that dopamine is an important immunoregulatory factor. Most types of immune cells express dopamine receptors and other dopaminergic proteins, and many immune cells take up, produce, store, and/or release dopamine, suggesting that dopaminergic immunomodulation is important for immune function. Targeting these pathways could be a promising avenue for the treatment of inflammation and disease, but despite increasing research in this area, data on the specific effects of dopamine on many immune cells and disease processes remain inconsistent and poorly understood. Therefore, this review integrates the current knowledge of the role of dopamine in immune cell function and inflammatory signaling across systems. We also discuss the current understanding of dopaminergic regulation of immune signaling in the CNS and peripheral tissues, highlighting the role of dopaminergic immunomodulation in diseases such as Parkinson's disease, several neuropsychiatric conditions, neurologic human immunodeficiency virus, inflammatory bowel disease, rheumatoid arthritis, and others. Careful consideration is given to the influence of experimental design on results, and we note a number of areas in need of further research. Overall, this review integrates our knowledge of dopaminergic immunology at the cellular, tissue, and disease level and prompts the development of therapeutics and strategies targeted toward ameliorating disease through dopaminergic regulation of immunity. SIGNIFICANCE STATEMENT: Canonically, dopamine is recognized as a neurotransmitter involved in the regulation of movement, cognition, and reward. However, dopamine also acts as an immune modulator in the central nervous system and periphery. This review comprehensively assesses the current knowledge of dopaminergic immunomodulation and the role of dopamine in disease pathogenesis at the cellular and tissue level. This will provide broad access to this information across fields, identify areas in need of further investigation, and drive the development of dopaminergic therapeutic strategies.

Interleukin-6-Production Is Responsible for Induction of Hepatic Synthesis of Several Chemokines as Acute-Phase Mediators in Two Animal Models: Possible Significance for Interpretation of Laboratory Changes in Severely Ill Patients

Simple Summary

The release of acute-phase proteins and cytokine storms are considered critical parameters for the progression of COVID-19 disease. The increase in the serum levels of cytokines such as IL6 and IL8 observed in patients primarily infected with the SARS-CoV-2 virus has been used to determine the severity of clinical conditions resulting from infection and for prognostic purposes. Animal models have been used to understand the mechanisms of the changes in homeostasis observed under pathological conditions. In the present study, we therefore report the changes in serum levels and hepatic gene expression of cytokines and chemokines in two different animal models of acute-phase responses. The acute-phase response is a transient emergency response aimed at preserving life and bringing about the changes necessary to reduce and repair tissue damage after the removal of damaging noxious agents. Our data suggest that the liver may be responsible for the increase in the serum levels of cytokines and chemokines as part of the body’s defense response to tissue damage. It is therefore doubtful that inhibiting this response at any stage after infection could improve the prognosis of patients. These results may help to interpret the laboratory changes observed in critically ill patients, as may be the case following SARS-CoV-2 infection.

Abstract

A mild to moderate increase in acute-phase proteins (APPs) and a decrease in serum albumin levels are detected in hospitalized COVID-19 patients. A similar trend is also observed for acute-phase cytokines (APC), mainly IL6, besides chemokines (e.g., CXCL8 and CCL2). However, the source of the chemokines in these patients at different stages of disease remains to be elucidated. We investigated hepatic gene expression of CXC- and CC-chemokines in a model of a localized extrahepatic aseptic abscess and in a model of septicemia produced by the intramuscular injection of turpentine oil (TO) into each hindlimb or lipopolysaccharide (LPS) intraperitoneally (i.p.) in rats and mice (wild-type (WT) and IL6-KO). Together with a striking increase in the serum IL6 level, strong serum CXCL2 and CXCL8 concentrations were detected. Correspondingly, rapid (2 h) upregulation of CXCL1, CXCL2, CXCL5, and CXCL8 was observed in rat liver after intramuscular TO injection. The induction of the gene expression of CXCL1 and CXCL8 was the fastest and strongest. The hepatic CXC-chemokines behaved like positive APPs that depend on IL6 production by activated macrophages recruited to extrahepatic damaged tissue. Chemokine upregulation was greatly reduced in IL6-KO mice. However, IL6 was dispensable in the LPS–APR model, as massive induction of hepatic chemokines studied was measured in IL6-KO mice.

Altered Levels of Plasma Inflammatory Cytokines and White Matter Integrity in Bipolar Disorder Patients With Suicide Attempts

OBJECTIVE

Bipolar disorder (BD) has a higher lifetime rate of suicide attempts (SA) than other psychiatric disorders. Furthermore, BD patients with SA (BD + S) are prone to a worse quality of life. However, the pathophysiology of BD + S is poorly understood. To further reveal the potential mechanisms of BD + S, abnormalities in peripheral plasma inflammatory cytokines and brain white matter (WM) in BD + S, as well as the correlation between them are investigated.

METHODS

We tested the levels of TNF-α, IL-1β, and IL-6 in peripheral plasma and collected the diffusion tensor imaging (DTI) data from 14 BD + S, 24 BD patients without SA (BD-S), and 26 healthy controls (HCs). The three groups were matched by age and gender. The levels of TNF-α, IL-1β, and IL-6 were detected by Luminex multifactor detection technology, and the fractional anisotropy (FA) values were employed to depict the alterations of WM. Partial correlation analyses were conducted to detect correlations between levels of TNF-α, IL-1β, and IL-6 and changes of WM, and the relationships between severity of clinical symptoms, including scores of HAMD-17 and YMRS, and cytokine levels or FA values in all groups.

RESULTS

For plasma inflammatory cytokines, there was no significant difference in their levels except for IL-6 among the three groups. Post-hoc analyses revealed that increased IL-6 level was only detected in BD + S (p < 0.05, Bonferroni correction). For DTI, BD + S showed specifically decreased FA in the bilateral middle cerebellar peduncle and the left superior corona radiata compared to BD-S and HCs (p < 0.05, Bonferroni correction). Additionally, both BD + S and BD-S groups revealed decreased FA in the bilateral body and genu of corpus callosum (CC) compared to HCs (p < 0.05, Bonferroni correction). No significant correlation between plasma inflammatory cytokines and WM integrity was found. In the BD + S group, we found negative correlation between the scores of YMRS and FA values of the left middle cerebellar peduncle (r = -0.74, p = 0.035).

CONCLUSION

The inflammation and impaired WM integrity may provide a scientific basis to understand the potential mechanisms of BD + S.

Antiviral Therapy with Entecavir following Antituberculosis Therapy Alleviates Liver Injury and Restores Innate Immunity in Tuberculosis Patients Coinfected with Hepatitis B Virus

Objective

Coinfection of tuberculosis (TB) and viral hepatitis may increase the risk of antituberculosis treatment-induced hepatotoxicity, which is regarded as a common cause of termination of the first-line antituberculosis drugs. The study aimed at investigating the protective effects of antiviral therapy on the liver and innate immunity in patients with TB-HBV coinfection.

Methods

A total of 100 patients with TB-HBV coinfection were recruited and split into antituberculosis and antiviral groups, 50 per group, according to odd or even date of hospital admission from December 2019 to October 2020. The patients in the anti-TB group received antituberculosis therapy, and those in the antiviral group received antiviral therapy. The clinical effectiveness; HBV-DNA negative conversion rate; liver function assessment involving alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL); immune function evaluation including CD4⁺, CD8⁺, CD4⁺/CD8⁺, and CD3⁺ T cells; inflammatory cytokines containing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interferon-γ (IFN-γ); and intestinal microflora including bifidobacterium, lactobacillus, enterobacterium, enterococcus, and clostridium were main outcome measures after treatment.

Results

It was found that the total response rate in the antiviral group was significantly higher than the anti-TB group after treatment (χ ² = 3.157, P=0.017). There was a significant difference in HBV-DNA negative conversion rates between the antiviral group and anti-TB group (82% vs. 58%, χ ² = 6.384, P=0.001). The ALT, AST, and TBIL in the two groups were all increased after treatment (P < 0.05), but the antiviral group indicated a rise of the above indices compared to the anti-TB group (P < 0.05). The two groups showed a rise on the concentration of CD3⁺, CD4⁺, and CD4⁺/CD8⁺ T cells and a decline on the CD8⁺ T cells after treatment (P < 0.05), but these changes in the antiviral group were more evident to those in the anti-TB group (P < 0.05). There was an increase on the IFN-γ level and decrease on the TNF-α and IL-6 levels in both groups after treatment (P < 0.05), but the antiviral group revealed a higher level of IFN-γ with lower levels of TNF-α and IL-6 compared to the anti-TB group (P < 0.05). After treatment, the number of bifidobacteria and lactobacilli was increased, and the number of enterobacteria, enterococci, and clostridium were decreased in the two groups (P < 0.05), while these changes in the antiviral group were more remarkable compared to the anti-TB group (P < 0.05). There was no significant difference in the incidence of adverse reactions between the two groups (χ2 = 0.267, P=0.731).

Conclusion

Antiviral therapy for tuberculosis-HBV coinfected patients could inhibit HBV replication, providing protection against liver damage, improving innate immunity, and balancing intestinal microflora.

Interleukin 8 as predictive factor for response to chemotherapy in colorectal cancer patients

Background: Colorectal cancer (CRC) represents a major public health problem owing to the fact that many patients are diagnosed in locally advanced or metastatic stage when chemotherapy is the only remaining option. However, treatment response is still unpredictable and depends upon a diversity of factors such as tumor inherited or acquired drug resistance and the host immune response to the malignant cells. The aim of this study was to evaluate the serum levels of interleukin 6, 8, 10 (IL-6, 8, 10) as possible predictive factors for response to chemotherapy and the correlation between the cytokines and the psychological distress.Methods: Forty-nine patients undergoing chemotherapy for locally advanced or metastatic CRC were included, for each patient IL-6, 8 and 10 were assessed through ELISA. Depression and anxiety were quantified through questionnaires. Statistical data were performed with GraphPad.Results: Patients with CRC had high serum levels of IL-8 and IL-6 compared to the healthy control group. High levels of IL-8 before treatment were correlated with progressive disease. There was a high incidence of psychological complication in CRC patients, especially in young male patients, from an urban area, with a positive correlation between serum levels of IL-8 and depression.Conclusions: These results indicate that high serum levels of IL-8 are predictive factors in CRC patients that undergo chemotherapy, but also could be useful in identifying psychological distress associated with this pathology.

Prefrontal dopamine D1 receptor manipulation influences anxiety behavior and induces neuroinflammation within the hippocampus

Background

Prefrontal dopamine D1 receptor (D1R) mediates behavior related to anxiety, reward and memory, and is involved in inflammatory processes, all of which are affected in bipolar disorder. Interleukin-6 (IL-6), a pro-inflammatory cytokine, is increased in patients with bipolar disorder in plasma samples, imaging studies and postmortem tissue and is an indicator for an inflammatory state. We could previously show that lentiviral overexpression of D1R in the medial prefrontal cortex (mPFC) of male adult rats and its termination induces bipolar disorder-like behavior. The purpose of this study was to investigate anxiety and the role of the immune system, specifically IL-6 positive neurons in this animal model. Due to its high density of inflammatory mediator receptors and therewith sensibility to immune activation, the hippocampus was investigated.

Methods

Expression of the gene for D1R in glutamatergic neurons within the mPFC of male, adult rats was manipulated through an inducible lentiviral vector. Animals over-expressing the gene (mania-like state), after termination of the expression (depressive-like) and their respective control groups were investigated. Anxiety behavior was studied in the elevated plus maze and marble burying test. Furthermore, IL-6-positive cells were counted within several subregions of the hippocampus.

Results

D1R manipulation in the mPFC had only mild effects on anxiety behavior in the elevated plus maze. However, subjects after termination buried more marbles compared to D1R over-expressing animals and their respective control animals indicating elevated anxiety behavior. In addition, animals in the depressive-like state showed higher numbers of IL-6 positive cells reflecting an elevated pro-inflammatory state in the hippocampus, in the CA3 and dentate gyrus. Consistently, inflammatory state in the whole hippocampus and anxiety behavior correlated positively, indicating a connection between anxiety and inflammatory state of the hippocampus.

Conclusions

Behavioral and neurobiological findings support the association of manipulation of the D1R in the mPFC on anxiety and inflammation in the hippocampus. In addition, by confirming changes in the inflammatory state, the proposed animal model for bipolar disorder has been further validated.

Effects of tDCS on neuroplasticity and inflammatory biomarkers in bipolar depression: Results from a sham-controlled study

OBJECTIVES

We investigated the role of peripheral biomarkers associated with neuroplasticity and immune-inflammatory processes on the effects of transcranial direct current stimulation (tDCS), a safe, affordable, and portable non-invasive neuromodulatory treatment, in bipolar depression.

METHODS

This is an exploratory analysis using a dataset from the sham-controlled study the Bipolar Depression Electrical Treatment Trial (BETTER)(clinicaltrials.govNCT02152878). Participants were 52 adults with type I or II bipolar disorder in a moderate-to-severe depressive episode, randomized to 12 bifrontal active or sham tDCS sessions over a 6-week treatment course. Plasma levels of brain derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor (GDNF), interleukins (IL) 2, 4, 6, 8, 10, 18, 33, 1β, 12p70, 17a, interferon gamma (IFN), tumor necrosis factor alpha (TNF) and its soluble receptors 1 and 2, ST2, and KLOTHO were investigated at baseline and endpoint. We performed analyses unadjusted for multiple testing to evaluate whether baseline biomarkers were predictive for depression improvement and changed during treatment using linear regression models.

RESULTS

A time x group interaction (Cohen's d: -1.16, 95% CI = -1.96 to -0.3, p = .005) was found for IL-8, with greater reductions after active tDCS. Higher baseline IL-6 plasma levels was associated with symptomatic improvement after tDCS (F_(1,43) = 5.43; p = .025). Other associations were not significant.

CONCLUSIONS

Our exploratory findings suggested that IL-6 is a potential predictor of tDCS response and IL-8 might decrease after tDCS; although confirmatory studies are warranted due to the multiplicity of comparisons.

Inflammation is correlated with abnormal functional connectivity in unmedicated bipolar depression: an independent component analysis study of resting-state fMRI

BACKGROUND

Inflammation might play a role in bipolar disorder (BD), but it remains unclear the relationship between inflammation and brain structural and functional abnormalities in patients with BD. In this study, we focused on the alterations of functional connectivity (FC), peripheral pro-inflammatory cytokines and their correlations to investigate the role of inflammation in FC in BD depression.

METHODS

In this study, 42 unmedicated patients with BD II depression and 62 healthy controls (HCs) were enrolled. Resting-state-functional magnetic resonance imaging was performed in all participants and independent component analysis was used. Serum levels of Interleukin-6 (IL-6) and Interleukin-8 (IL-8) were measured in all participants. Correlation between FC values and IL-6 and IL-8 levels in BD was calculated.

RESULTS

Compared with the HCs, BD II patients showed decreased FC in the left orbitofrontal cortex (OFC) implicating the limbic network and the right precentral gyrus implicating the somatomotor network. BD II showed increased IL-6 (p = 0.039), IL-8 (p = 0.002) levels. Moreover, abnormal FC in the right precentral gyrus were inversely correlated with the IL-8 (r = -0.458, p = 0.004) levels in BD II. No significant correlation was found between FC in the left OFC and cytokines levels.

CONCLUSIONS

Our findings that serum IL-8 levels are associated with impaired FC in the right precentral gyrus in BD II patients suggest that inflammation might play a crucial role in brain functional abnormalities in BD.

Cutaneous melanoma dissemination is dependent on the malignant cell properties and factors of intercellular crosstalk in the cancer microenvironment (Review)

The incidence of cutaneous malignant melanoma has been steadily increasing worldwide for several decades. This phenomenon seems to follow the trend observed in many types of malignancies caused by multiple significant factors, including ageing. Despite the progress in cutaneous malignant melanoma therapeutic options, the curability of advanced disease after metastasis represents a serious challenge for further research. In this review, we summarise data on the microenvironment of cutaneous malignant melanoma with emphasis on intercellular signalling during the disease progression. Malignant melanocytes with features of neural crest stem cells interact with non‑malignant populations within this microenvironment. We focus on representative bioactive factors regulating this intercellular crosstalk. We describe the possible key factors and signalling cascades responsible for the high complexity of the melanoma microenvironment and its premetastatic niches. Furthermore, we present the concept of melanoma early becoming a systemic disease. This systemic effect is presented as a background for the new horizons in the therapy of cutaneous melanoma.

Hypothesis: bipolar disorder is an Epstein-Barr virus-driven chronic autoimmune disease - implications for immunotherapy

Bipolar disorder (BD) is a chronic disease characterised by episodes of major depression and episodes of mania or hypomania, with a worldwide prevalence of 2.4%. The cause of BD is unknown. Here, I propose the hypothesis that BD is a chronic autoimmune disease caused by Epstein–Barr virus (EBV) infection of autoreactive B cells. It is postulated that EBV‐infected autoreactive B cells accumulate in the brain where they provide costimulatory survival signals to autoreactive T cells and differentiate into plasma cells producing pathogenic autoantibodies targeting brain components such as the N‐methyl‐D‐aspartate receptor. It is also proposed that the accumulation of EBV‐infected autoreactive B cells in the brain is a consequence of a genetically determined defect in the ability of CD8⁺ T cells to control EBV infection. The theory is supported by studies indicating that autoimmunity, EBV infection and CD8⁺ T‐cell deficiency all have roles in the pathogenesis of BD. According to the hypothesis, BD should be able to be treated by EBV‐specific T‐cell therapy and to be prevented by vaccination against EBV in early childhood. Exposure to sunlight or appropriate artificial light should also be beneficial in BD by augmenting CD8⁺ T‐cell control of EBV infection.

[Determination of some indicators of immunity and lipoperoxidation in the oral fluid in persons with a low vitamin D level.]

Oral fluid is a unique biological environment, containing a wide range of substances, coming from local and systemic sources, which makes it possible to use it as an object for assessing pathological changes in the body both at the local and systemic levels. In comparison with the traditional method of blood analysis, the advantage of evaluating the parameters of the oral fluid is the non-invasive of this method of obtaining material. All patients underwent oral fluid sampling using special plastic containers with a swab, which facilitate the selection of material, eliminating the penetration of mucin into a clean test sample, which helps to obtain more accurate analysis results. The amount of secretory IgA, lipopolysaccharide-binding protein (LBP), TBA-active products, the level of total antioxidant activity in the oral fluid in individuals with a low level of 25(OH)D before and after taking the native solution of vitamin D "Aqua Trim" were determined. The concentrations of secretory immunoglobulin A, lipopolysaccharide, binding protein and the level of total antioxidant activity are reduced in the oral fluid of people with vitamin D deficiency, but the number of intermediate products of lyoperoxidation increases. The course intake of the native solution of vitamin D (International Nonproprietary Name - Colecalciferol) normalizes the functioning of the immunity of the oral cavity and restores the balance of the "lipid peroxidation-antioxidants" system.