Inflammatory cytokines and nuclear factor-kappa B activation in adolescents with bipolar and major depressive disorders

Inflammatory and oxidative stress biomarkers in children and adolescents with bipolar disorder - A systematic review and meta-analysis

Evidence suggests a role for low-grade inflammation and oxidative stress in the pathophysiology of bipolar disorder. We conducted a systematic review and meta-analysis of peripheral markers of inflammation and oxidative stress in children and adolescents under 20 years of age with bipolar disorder. We searched PubMed, Embase and psycINFO and performed random effects meta-analysis calculating standardized mean differences (SMD) of marker levels between patients with bipolar disorder and healthy control individuals. Ten studies comprising a total of 418 patients with bipolar disorder and 3017 healthy control individuals were included. The levels of C-Reactive Protein were higher in patients with bipolar disorder compared with healthy individuals (SMD 0.53; 95 %CI: 0.33-0.74; I2 = 0 %). For other biomarkers there were no statistically significant differences between groups. Findings were limited by a low number of studies and participants and methodological issues in the included studies. More and larger studies using rigorous methodology are needed to establish the role of inflammation and oxidative stress in children and adolescents with bipolar disorder.

Molecular signatures of astrocytes and microglia maladaptive responses to acute stress are rescued by a single administration of ketamine in a rodent model of PTSD

Stress affects the brain and alters its neuroarchitecture and function; these changes can be severe and lead to psychiatric disorders. Recent evidence suggests that astrocytes and microglia play an essential role in the stress response by contributing to the maintenance of cerebral homeostasis. These cells respond rapidly to all stimuli that reach the brain, including stressors. Here, we used a recently validated rodent model of post-traumatic stress disorder in which rats can be categorized as resilient or vulnerable after acute inescapable footshock stress. We then investigated the functional, molecular, and morphological determinants of stress resilience and vulnerability in the prefrontal cortex, focusing on glial and neuronal cells. In addition, we examined the effects of a single subanesthetic dose of ketamine, a fast-acting antidepressant recently approved for the treatment of resistant depression and proposed for other stress-related psychiatric disorders. The present results suggest a prompt glial cell response and activation of the NF-κB pathway after acute stress, leading to an increase in specific cytokines such as IL-18 and TNF-α. This response persists in vulnerable individuals and is accompanied by a significant change in the levels of critical glial proteins such as S100B, CD11b, and CX43, brain trophic factors such as BDNF and FGF2, and proteins related to dendritic arborization and synaptic architecture such as MAP2 and PSD95. Administration of ketamine 24 h after the acute stress event rescued many of the changes observed in vulnerable rats, possibly contributing to support brain homeostasis. Overall, our results suggest that pivotal events, including reactive astrogliosis, changes in brain trophic factors, and neuronal damage are critical determinants of vulnerability to acute traumatic stress and confirm the therapeutic effect of acute ketamine against the development of stress-related psychiatric disorders.

Role of brain renin-angiotensin system in depression: A new perspective

Depression is a mood disorder characterized by abnormal thoughts. The pathophysiology of depression is related to the deficiency of serotonin (5HT), which is derived from tryptophan (Trp). Mitochondrial dysfunction, oxidative stress, and neuroinflammation are involved in the pathogenesis of depression. Notably, the renin-angiotensin system (RAS) is involved in the pathogenesis of depression, and different findings revealed that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may be effective in depression. However, the underlying mechanism for the role of dysregulated brain RAS-induced depression remains speculative. Therefore, this review aimed to revise the conceivable role of ACEIs and ARBs and how these agents ameliorate the pathophysiology of depression. Dysregulation of brain RAS triggers the development and progression of depression through the reduction of brain 5HT and expression of brain-derived neurotrophic factor (BDNF) and the induction of mitochondrial dysfunction, oxidative stress, and neuroinflammation. Therefore, inhibition of central classical RAS by ARBS and ACEIs and activation of non-classical RAS prevent the development of depression by regulating 5HT, BDNF, mitochondrial dysfunction, oxidative stress, and neuroinflammation.

Possible Role of Correlation Coefficients and Network Analysis of Multiple Intracellular Proteins in Blood Cells of Patients with Bipolar Disorder in Studying the Mechanism of Lithium Responsiveness: A Proof-Concept Study

Background: The mechanism of lithium treatment responsiveness in bipolar disorder (BD) remains unclear. The aim of this study was to explore the utility of correlation coefficients and protein-to-protein interaction (PPI) network analyses of intracellular proteins in monocytes and CD4+ lymphocytes of patients with BD in studying the potential mechanism of lithium treatment responsiveness. Methods: Patients with bipolar I or II disorder who were diagnosed with the MINI for DSM-5 and at any phase of the illness with at least mild symptom severity and received lithium (serum level ≥ 0.6 mEq/L) for 16 weeks were divided into two groups, responders (≥50% improvement in Montgomery-Asberg Depression Rating Scale and/or Young Mania Rating Scale scores from baseline) and non-responders. Twenty-eight intracellular proteins/analytes in CD4+ lymphocytes and monocytes were analyzed with a tyramine-based signal-amplified flow cytometry procedure. Correlation coefficients between analytes at baseline were estimated in both responders and non-responders and before and after lithium treatment in responders. PPI network, subnetwork, and pathway analyses were generated based on fold change/difference in studied proteins/analytes between responders and non-responders. Results: Of the 28 analytes from 12 lithium-responders and 11 lithium-non-responders, there were more significant correlations between analytes in responders than in non-responders at baseline. Of the nine lithium responders with pre- and post-lithium blood samples available, the correlations between most analytes were weakened after lithium treatment with cell-type specific patterns in CD4+ lymphocytes and monocytes. PPI network/subnetwork and pathway analyses showed that lithium response was involved in four pathways, including prolactin, leptin, neurotrophin, and brain-derived neurotrophic factor pathways. Glycogen synthase kinase 3 beta and nuclear factor NF-kappa-B p65 subunit genes were found in all four pathways. Conclusions: Using correlation coefficients, PPI network/subnetwork, and pathway analysis with multiple intracellular proteins appears to be a workable concept for studying the mechanism of lithium responsiveness in BD. Larger sample size studies are necessary to determine its utility.

Adolescent intermittent ethanol (AIE) produces lasting, sex-specific changes in rat body fat independent of changes in white blood cell composition

Early initiation of alcohol use during adolescence, and adolescent binge drinking are risk factors for the development of alcohol use disorder later in life. Adolescence is a time of rapid sex-dependent neural, physiological, and behavioral changes as well as a period of heightened vulnerability to many effects of alcohol. The goal of the present studies was to determine age-related changes in blood (leukocyte populations) and body composition across adolescence and early adulthood, and to investigate whether adolescent intermittent ethanol (AIE) exposure would alter the trajectory of adolescent development on these broad physiological parameters. We observed significant ontogenetic changes in leukocyte populations that were mirrored by an age-related increase in cytokine expression among mixed populations of circulating leukocytes. Despite these developmental changes, AIE did not significantly alter overall leukocyte numbers or cytokine gene expression. However, AIE led to sex-specific changes in body fat mass and fat percentage, with AIE-exposed male rats showing significantly decreased fat levels and female rats showing significantly increased fat levels relative to controls. These changes suggest that while AIE may not alter overall leukocyte levels, more complex phenotypic changes in leukocyte populations could underlie previously reported differences in cytokine expression. Coupled with long-term shifts in adipocyte levels, this could have long-lasting effects on innate immunity and the capacity of individuals to respond to later immunological and physiological threats.

Antidepressant mechanisms of ketamine's action: NF-κB in the spotlight

Ketamine recently approved for therapy of treatment-resistant depression shows a complex and not fully understood mechanism of action. Apart from its classical glutamatergic N-methyl-D-aspartate receptor antagonistic action, it is thought that anti-inflammatory properties of the drug are of clinical relevance due to the contribution of activated inflammatory mediators to the pathophysiology of depression and non-responsiveness of a group of patients to current antidepressant therapies. In a search of the mechanism underlying anti-inflammatory effects of ketamine, the nuclear factor kappa B transcription factor (NF-κB) has been proposed as a target for ketamine. The NF-κB forms precisely regulated protein signaling cascades enabling a rapid response to cellular stimuli. In the central nervous systems, NF-κB signaling appears to have pleiotropic but double-edged functions: on the one hand it participates in the regulation of processes that are crucial in the treatment of depression, such as neuroplasticity, neurogenesis or neuronal survival, on the other - in the activation of neuroinflammation and cell death. Ketamine has been found to reduce inflammation mediated by NF-κB, leading to decreased level of pro-inflammatory cytokines and other inflammatory or stress mediators. Therefore, this review presents recent data on the significance of the NF-κB cascade in the mechanism of ketamine's action and its future perspectives in designing new strategies for the treatment of depression.

Altered IL-3 and lipocalin-2 levels are associated with the pathophysiology of major depressive disorder: a case-control study

BACKGROUND

Major Depressive Disorder (MDD) is a common mental ailment and is the primary reason for disability. It manifests a severe impact on moods, thoughts, and physical health. At present, this disorder has become a concern in the field of public health. Alteration of neurochemicals is thought to be involved in the pathogenesis of many psychiatric disorders. Therefore, we aimed to evaluate serum IL-3 and lipocalin-2 in MDD patients and healthy controls (HCs).

METHOD

We included a total of 376 participants in this study. Among them, 196 were MDD patients, and 180 were age-sex-matched HCs. MDD patients were recruited from the Psychiatry Department of Bangabandhu Sheikh Mujib Medical University (BSMMU), but the controls were from different parts of Dhaka. All study participants were evaluated by a psychiatrist using the DSM-5 criteria. To assess the severity of the depression, we used the Hamilton depression (Ham-D) rating scale. Serum IL-3 and lipocalin-2 levels were measured using commercially available enzyme-linked immune-sorbent assay kits (ELISA kits).

RESULTS

According to this study, we observed elevated serum levels of IL-3 (1,024.73 ± 29.84 pg/mL) and reduced levels of serum lipocalin-2 (29.019 ± 2.073 ng/mL) in MDD patients compared to HCs (911.11 ± 20.55 pg/mL and 48.065 ± 3.583 ng/mL, respectively). No associations between serum levels of IL-3 and lipocalin-2 and depression severity were observed in patients.

CONCLUSIONS

According to the present findings, alterations of serum IL-3 and lipocalin might be associated with the pathogenesis of MDD. These results support that altered serum neurochemicals can serve as early risk assessment markers for depression. Further interventional studies are recommended for a better understanding of the role of IL-3 and lipocalin-2 in the pathophysiology of depression.

Reverse cholesterol transport and lipid peroxidation biomarkers in major depression and bipolar disorder: A systematic review and meta-analysis

BACKGROUND

Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses.

OBJECTIVES

To systematically review and meta-analyze all data concerning biomarkers of reverse cholesterol transport (RCT), lipid-associated antioxidants, lipid peroxidation products, and autoimmune responses to oxidatively modified lipid epitopes in MDD and BD.

METHODS

Databases including PubMed, Google scholar and SciFinder were searched to identify eligible studies from inception to January 10th, 2023. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

The current meta-analysis included 176 studies (60 BD and 116 MDD) and examined 34,051 participants, namely 17,094 with affective disorders and 16,957 healthy controls. Patients with MDD and BD showed a) significantly decreased RCT (mainly lowered high-density lipoprotein cholesterol and paraoxonase 1); b) lowered lipid soluble vitamins (including vitamin A, D, and coenzyme Q10); c) increased lipid peroxidation and aldehyde formation, mainly increased malondialdehyde (MDA), 4-hydroxynonenal, peroxides, and 8-isoprostanes; and d) Immunoglobulin (Ig)G responses to oxidized low-density lipoprotein and IgM responses to MDA. The ratio of all lipid peroxidation biomarkers/all lipid-associated antioxidant defenses was significantly increased in MDD (standardized mean difference or SMD = 0.433; 95% confidence intervals (CI): 0.312; 0.554) and BD (SMD = 0.653; CI: 0.501-0.806). This ratio was significantly greater in BD than MDD (p = 0.027).

CONCLUSION

In MDD/BD, lowered RCT, a key antioxidant and anti-inflammatory pathway, may drive increased lipid peroxidation, aldehyde formation, and autoimmune responses to oxidative specific epitopes, which all together cause increased immune-inflammatory responses and neuro-affective toxicity.

Deregulation of NF-κB associated long non-coding RNAs in bipolar disorder

Long non-coding RNAs (lncRNAs) are major genetic factors whose disruption lead to many diseases, including nervous system diseases. Bipolar disorder (BD) is a neuro-psychiatric disease with no definitive diagnosis and incomplete treatment. Regarding the role of NF-κB-associated lncRNAs in the neuro-psychiatric disorders, we examined the expression of three lncRNAs, DICER1-AS1, DILC, and CHAST, in BD patients. To assess lncRNA expression in peripheral blood mononuclear cells (PBMCs) of 50 BD patients and 50 healthy individuals, Real-time PCR was used. Additionally, some clinical characteristics of BD patients were investigated via an analysis of ROC curves and correlations. Based on our results, the expression level of CHAST increased significantly in BD patients in comparison with healthy people, in BD men compared with healthy men, as well as in BD women in comparison with control females (p < 0.05). A similar increase in expression was observed for DILC and DICER1-AS1 lncRNAs in female patients compared with healthy women. Whereas compared to healthy men, DILC was decreased in diseased men. Based on the results of the ROC curve, the area under the curve (AUC) for CHAST lncRNA was 0.83 with a P value of 0.0001. So, the expression level of CHAST lncRNA could play a role in the pathobiology of the BD and be considered a good putative biomarker for individuals with bipolar disorder.

Differentiation between bipolar disorder and major depressive disorder in adolescents: from clinical to biological biomarkers

Background

Mood disorders are very common among adolescents and include mainly bipolar disorder (BD) and major depressive disorder (MDD), with overlapping depressive symptoms that pose a significant challenge to realizing a rapid and accurate differential diagnosis in clinical practice. Misdiagnosis of BD as MDD can lead to inappropriate treatment and detrimental outcomes, including a poorer ultimate clinical and functional prognosis and even an increased risk of suicide. Therefore, it is of great significance for clinical management to identify clinical symptoms or features and biological markers that can accurately distinguish BD from MDD. With the aid of bibliometric analysis, we explore, visualize, and conclude the important directions of differential diagnostic studies of BD and MDD in adolescents.

Materials and methods

A literature search was performed for studies on differential diagnostic studies of BD and MDD among adolescents in the Web of Science Core Collection database. All studies considered for this article were published between 2004 and 2023. Bibliometric analysis and visualization were performed using the VOSviewer and CiteSpace software.

Results

In total, 148 publications were retrieved. The number of publications on differential diagnostic studies of BD and MDD among adolescents has been generally increasing since 2012, with the United States being an emerging hub with a growing influence in the field. Boris Birmaher is the top author in terms of the number of publications, and the Journal of Affective Disorders is the most published journal in the field. Co-occurrence analysis of keywords showed that clinical characteristics, genetic factors, and neuroimaging are current research hotspots. Ultimately, we comprehensively sorted out the current state of research in this area and proposed possible research directions in future.

Conclusion

This is the first-ever study of bibliometric and visual analyses of differential diagnostic studies of BD and MDD in adolescents to reveal the current research status and important directions in the field. Our research and analysis results might provide some practical sources for academic scholars and clinical practice.

Sex and cell-specific gene expression in corticolimbic brain regions associated with psychiatric disorders revealed by bulk and single-nuclei RNA sequencing

BACKGROUND

There are sex-specific differences in the prevalence, symptomology and course of psychiatric disorders. However, preclinical models have primarily used males, such that the molecular mechanisms underlying sex-specific differences in psychiatric disorders are not well established.

METHODS

In this study, we compared transcriptome-wide gene expression profiles in male and female rats within the corticolimbic system, including the cingulate cortex, nucleus accumbens medial shell (NAcS), ventral dentate gyrus and the basolateral amygdala (n = 22-24 per group/region).

FINDINGS

We found over 3000 differentially expressed genes (DEGs) in the NAcS between males and females. Of these DEGs in the NAcS, 303 showed sex-dependent conservation DEGs in humans and were significantly enriched for gene ontology terms related to blood vessel morphogenesis and regulation of cell migration. Single nuclei RNA sequencing in the NAcS of male and female rats identified widespread sex-dependent expression, with genes upregulated in females showing a notable enrichment for synaptic function. Female upregulated genes in astrocytes, Drd3+MSNs and oligodendrocyte were also enriched in several psychiatric genome-wide association studies (GWAS).

INTERPRETATION

Our data provide comprehensive evidence of sex- and cell-specific molecular profiles in the NAcS. Importantly these differences associate with anxiety, bipolar disorder, schizophrenia, and cross-disorder, suggesting an intrinsic molecular basis for sex-based differences in psychiatric disorders that strongly implicates the NAcS.

FUNDING

This work was supported by funding from the Hope for Depression Research Foundation (MJM).

Multi-omics analysis of a drug-induced model of bipolar disorder in zebrafish

Emerging studies demonstrate that inflammation plays a crucial role in the pathogenesis of bipolar disorder (BD), but the underlying mechanism remains largely unclear. Given the complexity of BD pathogenesis, we performed high-throughput multi-omic profiling (metabolomics, lipidomics, and transcriptomics) of the BD zebrafish brain to comprehensively unravel the molecular mechanism. Our research proved that in BD zebrafish, JNK-mediated neuroinflammation altered metabolic pathways involved in neurotransmission. On one hand, disturbed metabolism of tryptophan and tyrosine limited the participation of the monoamine neurotransmitters serotonin and dopamine in synaptic vesicle recycling. On the other hand, dysregulated metabolism of the membrane lipids sphingomyelin and glycerophospholipids altered the synaptic membrane structure and neurotransmitter receptors (chrnα7, htr1b, drd5b, and gabra1) activity. Our findings revealed that disturbance of serotonergic and dopaminergic synaptic transmission mediated by the JNK inflammatory cascade was the key pathogenic mechanism in a zebrafish model of BD, provides critical biological insights into the pathogenesis of BD.

Differences in intracellular protein levels in monocytes and CD4+ lymphocytes between bipolar depressed patients and healthy controls: A pilot study with tyramine-based signal-amplified flow cytometry

BACKGROUND

Molecular biomarkers for bipolar disorder (BD) that distinguish it from other manifestations of depressive symptoms remain unknown. The aim of this study was to determine if a very sensitive tyramine-based signal-amplification technology for flow cytometry (CellPrint™) could facilitate the identification of cell-specific analyte expression profiles of peripheral blood cells for bipolar depression (BPD) versus healthy controls (HCs).

METHODS

The diagnosis of psychiatric disorders was ascertained with Mini International Neuropsychiatric Interview for DSM-5. Expression levels for eighteen protein analytes previously shown to be related to bipolar disorder were assessed with CellPrint™ in CD4⁺ T cells and monocytes of bipolar patients and HCs. Implementation of protein-protein interaction (PPI) network and pathway analysis was subsequently used to identify new analytes and pathways for subsequent interrogations.

RESULTS

Fourteen drug-naïve or -free patients with bipolar I or II depression and 17 healthy controls (HCs) were enrolled. The most distinguishable changes in analyte expression based on t-tests included GSK3β, HMGB1, IRS2, phospho-GSK3αβ, phospho-RELA, and TSPO in CD4⁺ T cells and calmodulin, GSK3β, IRS2, and phospho-HS1 in monocytes. Subsequent PPI and pathway analysis indicated that prolactin, leptin, BDNF, and interleukin-3 signal pathways were significantly different between bipolar patients and HCs.

LIMITATION

The sample size of the study was small and 2 patients were on medications.

CONCLUSION

In this pilot study, CellPrint™ was able to detect differences in cell-specific protein levels between BPD patients and HCs. A subsequent study including samples from patients with BPD, major depressive disorder, and HCs is warranted.

Flavonols in Action: Targeting Oxidative Stress and Neuroinflammation in Major Depressive Disorder

Major depressive disorder is one of the most common mental illnesses that highly impairs quality of life. Pharmacological interventions are mainly focused on altered monoamine neurotransmission, which is considered the primary event underlying the disease's etiology. However, many other neuropathological mechanisms that contribute to the disease's progression and clinical symptoms have been identified. These include oxidative stress, neuroinflammation, hippocampal atrophy, reduced synaptic plasticity and neurogenesis, the depletion of neurotrophic factors, and the dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. Current therapeutic options are often unsatisfactory and associated with adverse effects. This review highlights the most relevant findings concerning the role of flavonols, a ubiquitous class of flavonoids in the human diet, as potential antidepressant agents. In general, flavonols are considered to be both an effective and safe therapeutic option in the management of depression, which is largely based on their prominent antioxidative and anti-inflammatory effects. Moreover, preclinical studies have provided evidence that they are capable of restoring the neuroendocrine control of the HPA axis, promoting neurogenesis, and alleviating depressive-like behavior. Although these findings are promising, they are still far from being implemented in clinical practice. Hence, further studies are needed to more comprehensively evaluate the potential of flavonols with respect to the improvement of clinical signs of depression.

Prospective study on Maresin-1 and cytokine levels in medication-naïve adolescents with first-episode major depressive disorder

Background

Inflammation and immune activation may play a role in the pathological mechanism of Major Depressive Disorder (MDD). Evidence from cross-sectional and longitudinal studies of adolescents and adults has shown that MDD is associated with increased plasma pro-inflammatory cytokines (e.g., IL-1β, IL-6). It has been reported that Specialized Pro-resolving Mediators (SPMs) mediate inflammation resolution, and Maresin-1 can activate the process of inflammation and promote inflammation resolution by promoting macrophage phagocytosis. However, no clinical studies have been conducted to evaluate the relationship between the levels of Maresin-1 and cytokine and the severity of MDD symptomatology in adolescents.

Methods

40 untreated adolescent patients with primary and moderate to severe MDD and 30 healthy participants as the healthy control (HC) group aged between 13 and 18 years old were enrolled. They received clinical and Hamilton Depression Rating Scale (HDRS-17) evaluation and then, blood samples were collected. Patients in the MDD group were re-evaluated for HDRS-17, and blood samples were taken after a six to eight-week fluoxetine treatment.

Results

The adolescent patients with MDD had lower serum levels of Maresin-1 and higher serum levels of interleukin 6 (IL-6) compared with the HC group. Fluoxetine treatment alleviated depressive symptoms in MDD adolescent patients, which was reflected by higher serum levels of Maresin-1 and IL-4 and lower HDRS-17 scores, serum levels of IL-6, and IL-1β. Moreover, the serum level of Maresin-1 was negatively correlated with the depression severity scores on the HDRS-17.

Conclusion

Adolescent patients with primary MDD had lower levels of Maresin-1 and higher levels of IL-6 compared with the HC group, implying that the peripheral level of pro-inflammatory cytokines may be elevated in MDD, resulting in the insufficiency of inflammation resolution. The Maresin-1 and IL-4 levels increased after anti-depressant treatment, whereas IL-6 and IL-1β levels decreased significantly. Moreover, Maresin-1 level negatively correlated with depression severity, suggesting that reduced levels of Maresin-1 promoted the progression of MDD.

Resveratrol exerts anxiolytic-like effects through anti-inflammatory and antioxidant activities in rats exposed to chronic social isolation

Emerging evidence has confirmed resveratrol's (RES) antioxidant, anti-inflammatory, and antidepressant effects. The beneficial effects of RES were confirmed for several emotional and cognitive deficits. This research aimed to assess the impacts of RES on behavior and hippocampal levels of anti-inflammatory and pro-inflammatory factors in rats exposed to chronic social isolation (SI) stress, which is known to induce mental disorders such as depressive-like behavior. The animals were treated by RES (20, 40, or 80 mg/kg/intraperitoneally) for 28 days following a 28-day exposure to stress. Behavioral tests, including the forced swim test (FST), open-field test (OFT), tail suspension test (TST), and sucrose preference test (SPT), assessed depressive symptoms. Finally, the animals were sacrificed, and molecular studies (qPCR and ELISA) were performed. Exposure of animals to SI dramatically increased the immobility of animals in TST and FST, enhanced the time spent in the open-field peripheral zone of the OFT, and reduced the sucrose preference rate. In addition, SI increased serum levels of corticosterone and hippocampal content of MDA, whereas it reduced hippocampal SOD and CAT activities. Moreover, SI upregulated the expression of IL-10, IL-18, and IL-1β and downregulated the expression of TGF-β in the hippocampus. RES treatment (40 & 80 mg/kg) significantly improved the behavioral alterations through the modulation of neuroinflammation and oxidative stress. The 20 mg/kg RES dose was inefficient for treating SI-induced depressive-like behavior. These results indicated that RES attenuated depressive-like behavior in prolonged stressed animals. These properties might be associated with RES-mediated improvements in serum corticosterone and hippocampal inflammatory and oxidative stress biomarkers.

A gene expression analysis of long non-coding RNAs NKILA and PACER as well as their target genes, NF-κB and cox-2 in bipolar disorder patients

Bipolar disorder (BD) is a severe condition characterized by periods of mania and depression. Despite advances in the neurobiology of bipolar disorder, the exact etiology of the disease remains unclear. There is evidence that Inflammation is associated with bipolar disorder. COX-2 and NF-κB are two critical mediators in the inflammatory pathways. Long non-coding RNAs (lncRNAs) are a new class of non-coding RNAs that play a wide range of roles, especially in developing and maintaining normal brain functions. Two lncRNAs called PACER and NKILA control the expression of COX-2 and NF-κB genes, respectively. In this study, Expression levels of PACER and NKILA lncRNAs, as well as, COX-2 and NF-κB genes were measured in fifty patients with bipolar disorder and 50 healthy individuals by real-time PCR. Expression levels of NKILA and COX2 were considerably reduced in BD patients compared with healthy controls. Such significant downregulation in the expression of NKILA and PACER was only observed in male patients with BD compared with male healthy subjects. Also, according to the results of the ROC curve, the area under curve values for NKILA and COX2 were 0.68 and 0.52 respectively. Consequently, the NKILA gene could be considered a biomarker. By examining the degree of pairwise correlation between genes, all genes had a significant positive correlation with each other. Taken together, these results revealed a function for NKILA and PACER lncRNAs in the pathogenesis of BD.

Divergent Directionality of Immune Cell-Specific Protein Expression between Bipolar Lithium Responders and Non-Responders Revealed by Enhanced Flow Cytometry

Background and Objectives: There is no biomarker to predict lithium response. This study used CellPrint™ enhanced flow cytometry to study 28 proteins representing a spectrum of cellular pathways in monocytes and CD4⁺ lymphocytes before and after lithium treatment in patients with bipolar disorder (BD). Materials and Methods: Symptomatic patients with BD type I or II received lithium (serum level ≥ 0.6 mEq/L) for 16 weeks. Patients were assessed with standard rating scales and divided into two groups, responders (≥50% improvement from baseline) and non-responders. Twenty-eight intracellular proteins in CD4⁺ lymphocytes and monocytes were analyzed with CellPrint™, an enhanced flow cytometry procedure. Data were analyzed for differences in protein expression levels. Results: The intent-to-treat sample included 13 lithium-responders (12 blood samples before treatment and 9 after treatment) and 11 lithium-non-responders (11 blood samples before treatment and 4 after treatment). No significant differences in expression between the groups was observed prior to lithium treatment. After treatment, the majority of analytes increased expression in responders and decreased expression in non-responders. Significant increases were seen for PDEB4 and NR3C1 in responders. A significant decrease was seen for NR3C1 in non-responders. Conclusions: Lithium induced divergent directionality of protein expression depending on the whether the patient was a responder or non-responder, elucidating molecular characteristics of lithium responsiveness. A subsequent study with a larger sample size is warranted.

Antioxidant, Anti-Inflammatory, Anti-Menopausal, and Anti-Cancer Effects of Lignans and Their Metabolites

Since chronic inflammation can be seen in severe, long-lasting diseases such as cancer, there is a high demand for effective methods to modulate inflammatory responses. Among many therapeutic candidates, lignans, absorbed from various plant sources, represent a type of phytoestrogen classified into secoisolariciresionol (Seco), pinoresinol (Pino), matairesinol (Mat), medioresinol (Med), sesamin (Ses), syringaresinol (Syr), and lariciresinol (Lari). Lignans consumed by humans can be further modified into END or ENL by the activities of gut microbiota. Lignans are known to exert antioxidant and anti-inflammatory activities, together with activity in estrogen receptor-dependent pathways. Lignans may have therapeutic potential for postmenopausal symptoms, including cardiovascular disease, osteoporosis, and psychological disorders. Moreover, the antitumor efficacy of lignans has been demonstrated in various cancer cell lines, including hormone-dependent breast cancer and prostate cancer, as well as colorectal cancer. Interestingly, the molecular mechanisms of lignans in these diseases involve the inhibition of inflammatory signals, including the nuclear factor (NF)-κB pathway. Therefore, we summarize the recent in vitro and in vivo studies evaluating the biological effects of various lignans, focusing on their values as effective anti-inflammatory agents.

Expression analysis of NF-ƙB-related long non-coding RNAs in bipolar disorder

Bipolar disorder (BD) is a mental disorder that leads to abnormal swings in mood, energy, activity level, attention, and the capability to accomplish daily tasks. Several long non-coding RNAs (lncRNAs) are dysregulated in BD patients. We have compared expression levels of five NF-κB-associated lncRNAs, namely ANRIL, CEBPA-DT, H19, NKILA and HNF1A-AS1 in blood samples of BD patients compared with controls. While ANRIL, CEBPA-DT and HNF1-AS1 were significantly under-expressed in BD patients compared with controls, NKILA levels were higher in patients versus controls. Among differentially expressed genes, HFN1A-AS1 exhibited the best diagnostic parameters in the separation of patients from controls (AUC ± SD = 0.86 ± 0.03, sensitivity = 0.82, specificity = 0.82, P value < 0.0001). AUC values for NKILA, ANRIL and CEBPA-DT were 0.71, 0.68 and 0.65, respectively. In accordance with the previously reported participation of NF-ƙB in the pathophysiology of BD, the current study provides evidence for dysregulation of NF-κB-associated lncRNAs in BD.

Elevation of C-reactive protein in adolescent bipolar disorder vs. anxiety disorders

Bipolar disorder (BD) largely begins in adolescence, but diagnosis lags for years, causing significant morbidity and mortality, and demonstrating the need for better diagnostic tools. Suggesting an association between BD and immune activity, elevated levels of peripheral inflammatory markers, including C-reactive protein (CRP), have been found in adults with BD. As similar data are extremely limited in adolescents, this study examined CRP levels in adolescents with BD (n = 37) compared to those with anxiety disorders (ADs, n = 157) and healthy controls with no psychiatric diagnoses (HCs, n = 2760). CRP blood levels for patients aged 12-17 years were retrieved from a nationwide repository of deidentified clinical data. After excluding patients with inflammatory conditions, differences in CRP were examined using multivariate and weighted regressions (covariates: demographics and BMI). Mean CRP levels were significantly elevated in adolescents with BD relative to those with ADs and HCs. Mean CRP levels were lower in the ADs cohort versus HCs. Although CRP levels were significantly higher in males and younger patients, the significant between-cohort differences in CRP remained after controlling for multiple confounders. To our knowledge, our study is the first to compare CRP levels between adolescent BD, ADs, and HCs, comprising a novel and essential contribution. Our results suggest the presence of a unique immune process in adolescents with BD and indicate that CRP may represent a biomarker with a crucial role in the diagnostic assessment of adolescent BD.

Evaluation of Inflammatory Response System (IRS) and Compensatory Immune Response System (CIRS) in Adolescent Major Depression

Purpose

Nowadays, the role of two tightly interconnected systems, the inflammatory response system (IRS) and the compensatory immune response system (CIRS) in depression, is increasingly discussed. Various studies indicate pro-inflammatory activity in adolescent depression; however, there is an almost complete lack of findings about IRS and CIRS balance. Thus, we aimed to assess different IRS and CIRS indices, profiles, and IRS/CIRS ratios in drug-naïve MDD patients at adolescent age, with respect to sex.

Patients and Methods

One hundred MDD adolescents (40 boys, average age: 15.4±1.2 yrs.) and 60 controls (28 boys, average age: 15.3±1.5 yrs.) were examined. Evaluated parameters were 1. plasma levels of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, interferon gamma, tumor necrosis factor alpha (TNF-α), soluble receptor of IL-6 (sIL-6R), soluble receptors of TNF-α (sTNF-R1, sTNF-R2); 2. profiles: IL-6 trans-signaling, M1 macrophage signaling, helper T lymphocytes (Th) 1 profile, regulatory T lymphocytes (Treg)+Th2, allIRS, and allCIRS; 3. IRS vs CIRS activity ratios: TNF-α/TNF-R1, TNF-α/TNF-R2, TNF-α/sTNF-Rs (ie sTNF-R1+sTNF-R2), Th1/Th2, Th1/Treg, Th1/Th2+Treg, M1/Th2, M1/Treg, M1/Treg+Th2, allIRS/allCIRS.

Results

MDD patients showed increased IL-4, IL-10, TNF-α, sIL-6R, Treg+Th2, allIRS, allCIRS, and TNF-α/sTNF-Rs, and decreased Th1/Th2+Treg. MDD females showed increased IL-10 and TNF-α compared to control females. MDD males showed increased IL-4, IL-10, sIL-6R, Treg+Th2, and TNF-α/TNF-R1 compared to control males. Increased sTNF-R1 was found in MDD males compared to MDD females. Positive correlations were found between CDI score and sIL-6R and IL-10 in the total group and between CDI score and IL-10 in adolescent males.

Conclusion

Our study for the first time extensively evaluated IRS and CIRS interactions revealing enhanced pro-inflammatory TNF-α signaling and IL-6 trans-signaling in association with increased IL-10- and IL-4-mediated anti-inflammatory activity in first-episode depression at the adolescent age. Moreover, results reflect the sex-specific simultaneous activation of IRS and CIRS pathways in adolescent depression.

Cytokine alterations in pediatric internalizing disorders: Systematic review and exploratory multi-variate meta-analysis

Pediatric internalizing disorders are prevalent and characterized by a maladaptive cognitive, emotional response to a perceived stressor. The hypothesized effect of this response is observable changes in behavior mediated by homeostatic inflammatory cytokines. The aim of this study was to synthesize the literature and analyze the effect of cytokines on pediatric internalizing disorders. Influential moderating variables, including mean body mass index, fasting status at blood collection, participant sex, cytokine type, mean age, percentage of sample medicated, and diagnosis, were also assessed. A systematic literature search was performed in electronic databases (Medline, PubMed, and PsycINFO) from January 1, 1980 to June 15, 2022. Case-control studies of pediatric internalizing disorders, specifically anxiety and depression, were reviewed for their association with peripheral cytokine levels. Meta-analyses were performed using a random effects multi-variate model and effect sizes were calculated using Hedge's g for IL-2, CRP, IL-6, TNF-α, IL-1β, IFN-γ, and IL-10. Thirty-three studies were reviewed and 28 studies were included in the meta-analysis (n = 1322 cases and n = 3617 controls). Peripheral cytokine levels were elevated in pediatric internalizing disorders compared to controls (Hedge's g = 0.19, p < 0.001). In the moderator analyses, depression diagnosis (Hedge's g = 0.18, p = 0.009) and non-fasting blood collection (Hedge's g = 0.20, p = 0.006) were significant. The meta-analytic findings are limited by methodological variation between studies, high heterogeneity, and low statistical power. Despite this, the findings suggest that elevated peripheral cytokine levels may play a role in the etiology and/or symptom maintenance of pediatric internalizing disorders.

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Depression diagnosis and non-fasting blood collection were observed to significantly influenced peripheral cytokine levels.

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No individual peripheral cytokines tested were associated with pediatric internalizing disorders.

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Overall, elevated peripheral cytokines were observed in pediatric internalizing disorders compared to controls.

Cellular and immunometabolic mechanisms of inflammation in depression: Preliminary findings from single cell RNA sequencing and a tribute to Bruce McEwen

Inflammation is associated with symptoms of anhedonia, a core feature of major depression (MD). We have shown that MD patients with high inflammation as measured by plasma C-reactive protein (CRP) and anhedonia display gene signatures of metabolic reprograming (e.g., shift to glycolysis) necessary to sustain cellular immune activation. To gain preliminary insight into the immune cell subsets and transcriptomic signatures that underlie increased inflammation and its relationship with behavior in MD at the single-cell (sc) level, herein we conducted scRNA-Seq on peripheral blood mononuclear cells from a subset of medically-stable, unmedicated MD outpatients. Three MD patients with high CRP (>3 mg/L) before and two weeks after anti-inflammatory challenge with the tumor necrosis factor antagonist infliximab and three patients with low CRP (≤3 mg/L) were studied. Cell clusters were identified using a Single Cell Wizard pipeline, followed by pathway analysis. CD14⁺ and CD16⁺ monocytes were more abundant in MD patients with high CRP and were reduced by 29% and 55% respectively after infliximab treatment. Within CD14⁺ and CD16⁺ monocytes, genes upregulated in high CRP patients were enriched for inflammatory (phagocytosis, complement, leukocyte migration) and immunometabolic (hypoxia-inducible factor [HIF]-1, aerobic glycolysis) pathways. Shifts in CD4⁺ T cell subsets included ∼30% and ∼10% lower abundance of CD4⁺ central memory (T_CM) and naïve cells and ∼50% increase in effector memory-like (T_EM-like) cells in high versus low CRP patients. T_CM cells of high CRP patients displayed downregulation of the oxidative phosphorylation (OXPHOS) pathway, a main energy source in this cell type. Following infliximab, changes in the number of CD14⁺ monocytes and CD4⁺ T_EM-like cells predicted improvements in anhedonia scores (r = 1.0, p < 0.001). In sum, monocytes and CD4⁺ T cells from MD patients with increased inflammation exhibited immunometabolic reprograming in association with symptoms of anhedonia. These findings are the first step toward determining the cellular and molecular immune pathways associated with inflammatory phenotypes in MD, which may lead to novel immunomodulatory treatments of psychiatric illnesses with increased inflammation.

Childhood trauma and the plasma levels of IL-6, TNF-α are risk factors for major depressive disorder and schizophrenia in adolescents: A cross-sectional and case-control study

BACKGROUND

It has been reported that childhood trauma and inflammation are associated with major depressive disorder (MDD) and schizophrenia (SZ), but previous researches were almost aimed at adults. The aim of the present research is to observe the alteration of peripheral interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in adolescents (12-20 years) with MDD and SZ, to investigate the impact of childhood abuse in early-onset MDD and SZ, and to furtherly explore the correlation between childhood maltreatment and plasma IL-6, TNF-α levels.

SUBJECTS AND METHODS

Enzyme-linked immunosorbent assay (ELISA) is applied to obtain the plasma concentrations of IL-6 and TNF-α in 55 patients with MDD, 51 patients with SZ and 47 healthy minors. The short form of the Childhood Trauma Questionnaire (CTQ-SF) is used to assess the severity of early trauma.

RESULTS

Plasma IL-6 and TNF-α levels are significantly elevated in patients with early-onset MDD and SZ compared with healthy subjects (p <0.01), whose results display that the correlation between IL-6 and TNF-α is significantly positive (γ=0.787, p <0.01) in all participants. Compared with the healthy adolescents, patients with MDD and SZ show more serious childhood trauma, and the plasma IL-6, TNF-α concentrations are closely related to childhood maltreatment.

CONCLUSIONS

Early trauma and peripheral inflammatory response play an important role in the pathophysiology of early-onset MDD or SZ. The current findings provide effective targets for the prevention, diagnosis, and treatment of major depressive disorder and schizophrenia in adolescents.

Elevated C-reactive protein among symptomatic youth with bipolar disorder

RATIONALE AND OBJECTIVES

Increased levels of high-sensitivity C-reactive protein (CRP) are associated with mood symptoms in adults with bipolar disorder (BD). The few studies on this topic in youth with BD have not included controls. We, therefore, examined CRP levels in relation to symptomatic status in youth with and without BD.

METHODS

Participants included 154 youth (mean age 17 years; 48 asymptomatic BD, 39 symptomatic BD, 67 healthy controls (HC)). Rank analysis of covariance test examined group differences in CRP, controlling for age and sex. Correlation between CRP and mood symptom severity was examined using Spearman's correlation within the BD group.

RESULTS

There were significant group differences in CRP levels (F_(2,151) = 5.06, p = 0.007, ηp2=0.06); post hoc analyses showed higher CRP levels in the symptomatic BD group compared with HC (p = 0.01). In sensitivity analyses, this finding was no longer significant after controlling for body mass index (BMI). CRP was not significantly associated with symptomatic severity.

CONCLUSIONS

CRP levels are elevated among symptomatic youth with BD, partly related to BMI. As elevated BMI is associated with mood symptom burden, prospective studies are warranted to parse the associations among mood symptoms, BMI, and inflammation. Given the proportion of time that youth with BD are symptomatic, present findings raise concern about the long-term impact of elevated CRP on blood vessels, brain, and related clinical outcomes.

Are pro-inflammatory markers associated with psychological distress in a cross-sectional study of healthy adolescents 15-17 years of age? The Fit Futures study

Background

Inflammatory markers have been associated with depression and anxiety disorder in adolescents. Less is known about the association between inflammation and subclinical symptoms in the form of psychological distress. We investigated prevalence of psychological distress and examined the associations between common pro-inflammatory markers and psychological distress in an adolescent population sample.

Methods

The study was based on data from 458 girls and 473 boys aged 15–17 years from the Fit Futures Study, a large-scale study on adolescent health, conducted in Northern Norway. Psychological distress was measured with the Hopkins Symptom Checklist (HSCL-10). Serum-levels of the following low-grade inflammatory markers were measured: C-reactive protein (CRP), interleukin 6 (IL-6), transforming growth factor-alpha (TGF-α), tumor necrosis factor alpha variant 1 (TRANCE) and tumor necrosis factor alpha variant 2 (TWEAK). Associations between quartiles of inflammatory markers and HSCL-10 were examined by logistic regression and adjusted for potential confounders in sex-stratified analyses.

Results

The proportion of psychological distress above cutoff were 26.9% and 10.8% among girls and boys, respectively. In both girls and boys, crude analysis showed positive associations between all inflammatory markers and HSCL-10, except for TWEAK and TRANCE in boys. However, none of these associations were statistically significant. Further, there were no significant findings in the adjusted analyses.

Conclusion

There was a higher prevalence of psychological distress in girls compared to boys. Pro-inflammatory markers were not significantly associated with psychological distress in data from healthy adolescents aged 15–17 years.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-022-00779-8.

Validating MARK2 Gene Polymorphism as a Predictor of Response to Lithium Treatment in Bipolar Patients

Background

Lithium is a therapeutic option for the treatment of the acute phase of the bipolar disorder and long-term management of this disorder. However, it is estimated that 10 to 60% of patients do not properly response to this medication.

Methods

To investigate the role of MARK2 gene in response to lithium, we genotyped the MARK2 rs10792421 polymorphism in Iranian bipolar patients using amplification Refractory Mutation System-PCR.

Results

Results of this study showed a significant association of this polymorphism with response to lithium. The A allele was more frequent in the responder than the non-responder group and also in the semi- responder group compared to the non-responder group in the codominant model of analysis. AA and AG genotypes were more frequent in both the responder and semi-responder groups compared to the non-responder group in dominant model of analysis.

Conclusion

Based on the findings of the current study, the rs10792421 variant of MARK2 gene could be considered as a potential biomarker for predicting the treatment outcome of bipolar disorder type 1 in Iranian population.

Protein Biomarkers in Monocytes and CD4+ Lymphocytes for Predicting Lithium Treatment Response of Bipolar Disorder: a Feasibility Study with Tyramine-Based Signal-Amplified Flow Cytometry

Purpose

To determine if enhanced flow cytometry (CellPrint™) can identify intracellular proteins of lithium responsiveness in monocytes and CD4⁺ lymphocytes from patients with bipolar disorder.

Methods

Eligible bipolar I or II patients were openly treated with lithium for 16-weeks. Baseline levels of Bcl2, BDNF, calmodulin, Fyn, phospho-Fyn/phospho-Yes, GSK3β, phospho-GSK3αβ, HMGB1, iNOS, IRS2, mTor, NLPR3, PGM1, PKA C-α, PPAR-γ, phospho-RelA, and TPH1 in monocytes and CD4⁺ lymphocytes of lithium responders and non-responders were measured with CellPrint™. Their utility of discriminating responders from non-responders was explored. Protein-protein network and pathway enrichment analyses were conducted.

Results

Of the 24 intent-to-treat patients, 12 patients completed the 16-week study. Eleven of 13 responders and 8 of 11 non-responders were available for this analysis. The levels of the majority of analytes in lithium responders were lower than non-responders in both cell types, but only the level of GSK3β in monocytes was significantly different (p = 0.034). The combination of GSK3β and phospho-GSK3αβ levels in monocytes correctly classified 11/11 responders and 5/8 non-responders. Combination of GSK3β, phospho-RelA, TPH1 and PGM1 correctly classified 10/11 responders and 6/7 non-responders, both with a likelihood of ≥ 85%. Prolactin, leptin, BDNF, neurotrophin, and epidermal growth factor/epidermal growth factor receptor signaling pathways are involved in the lithium treatment response. GSK3β and RelA genes are involved in 4 of 5 these pathways.

Conclusion

CellPrint™ flow cytometry was able to detect differences in multiple proteins in monocytes and CD4⁺ lymphocytes between lithium responders and non-responders. A large study is warranted to confirm or refute these findings.

Inflammatory markers, brain-derived neurotrophic factor, and the symptomatic course of adolescent bipolar disorder: A prospective repeated-measures study

BACKGROUND

Numerous studies have found elevated pro-inflammatory markers and reduced brain-derived neurotrophic factor (BDNF) during symptomatic episodes of bipolar disorder (BD) in adults. There is a paucity of research examining these markers in youth with BD, or longitudinally in any BD age group.

METHODS

79 adolescents, ages 13-19 years, were enrolled, including 43 symptomatic adolescents with BD and 36 age-matched healthy controls (HC). Blood samples were collected from all participants at intake, and repeatedly from BD participants at pre-specified intervals over the course of two years. Serum was assayed for levels of pro-inflammatory markers (c-reactive protein [CRP], interleukin [IL]-6, tumor necrosis factor alpha [TNF-α]), BDNF and the anti-inflammatory marker, IL-10. Week-by-week severity of mood symptoms was assessed using semi-structured interviews.

RESULTS

Adolescents with BD provided an average of 4.6 blood samples, on average every 5.0 months. During the most severe symptomatic interval (i.e., highest sum of mood symptom scores) among BD adolescents, levels of CRP (p = 0.01) and pro- to anti-inflammatory ratios (CRP/IL-10; p < 0.001 and IL-6/IL-10; p = 0.046) were significantly greater, and IL-10 levels (p = 0.004) were significantly lower, vs. HC. There were no differences between BD and HC in IL-6, TNF-α or BDNF. Within BD participants, higher BDNF (p = 0.01) and IL-10 levels (p = 0.001) significantly predicted greater burden of mood symptoms over the subsequent epoch. Moreover, higher CRP levels (p = 0.009) at intake predicted greater time to recovery from the index symptomatic episode.

CONCLUSIONS

In the first repeated-measures study on this topic in adolescents with BD, we found evidence that CRP, an inexpensive and ubiquitous blood test, may be useful in predicting the prospective course of BD symptoms. Future larger studies are warranted.

Vascular and blood-brain barrier-related changes underlie stress responses and resilience in female mice and depression in human tissue

Prevalence, symptoms, and treatment of depression suggest that major depressive disorders (MDD) present sex differences. Social stress-induced neurovascular pathology is associated with depressive symptoms in male mice; however, this association is unclear in females. Here, we report that chronic social and subchronic variable stress promotes blood-brain barrier (BBB) alterations in mood-related brain regions of female mice. Targeted disruption of the BBB in the female prefrontal cortex (PFC) induces anxiety- and depression-like behaviours. By comparing the endothelium cell-specific transcriptomic profiling of the mouse male and female PFC, we identify several pathways and genes involved in maladaptive stress responses and resilience to stress. Furthermore, we confirm that the BBB in the PFC of stressed female mice is leaky. Then, we identify circulating vascular biomarkers of chronic stress, such as soluble E-selectin. Similar changes in circulating soluble E-selectin, BBB gene expression and morphology can be found in blood serum and postmortem brain samples from women diagnosed with MDD. Altogether, we propose that BBB dysfunction plays an important role in modulating stress responses in female mice and possibly MDD.

Interleukin-8 and tumor necrosis factor-alpha in youth with mood disorders-A longitudinal study

Bipolar disorder (BD) is one of the most disabling psychiatric illnesses. Over half of BD patients experienced early onset of the disease, and in most cases, it begins with a depressed mood episode. Up to 50% of adolescents initially diagnosed with major depressive disorder (MDD) convert to bipolar spectrum disorder. Diagnostic tools or biomarkers to facilitate the prediction of diagnosis conversion from MDD to BD are still lacking. Our study aimed to find biomarkers of diagnosis conversion in young patients with mood disorders. We performed a 2-year follow-up study on 69 adolescent patients diagnosed with MDD or BD. The control group consisted of 31 healthy youths. We monitored diagnosis change from MDD to BD. Impulsiveness was assessed using Barratt Impulsiveness Scale (BIS-11) and defense mechanisms using Defense Style Questionnaire (DSQ-40). According to the immunological hypothesis of mood disorders, we investigated baseline cytokines levels either in depressive or hypomanic/manic episodes. We correlated interleukin 8 (IL-8) and Tumor Necrosis Factor-alpha (TNF-alpha) levels with clinical factors. We detected higher IL-8 and TNF-alpha in patients in hypomanic/manic compared to depressed episodes. We found correlations of cytokine levels with immature defense style. We did not discover predictors of diagnosis conversion from MDD to BD.

Inflammation and depression in young people: a systematic review and proposed inflammatory pathways

Depression onset peaks during adolescence and young adulthood. Current treatments are only moderately effective, driving the search for novel pathophysiological mechanisms underlying youth depression. Inflammatory dysregulation has been shown in adults with depression, however, less is known about inflammation in youth depression. This systematic review identified 109 studies examining the association between inflammation and youth depression and showed subtle evidence for inflammatory dysregulation in youth depression. Longitudinal studies support the bidirectional association between inflammation and depression in youth. We hypothesise multiple inflammatory pathways contributing to depression. More research is needed on anti-inflammatory treatments, potentially tailored to individual symptom profiles.

Quercetin reverses chronic unpredictable mild stress-induced depression-like behavior in vivo by involving nuclear factor-E2-related factor 2

Quercetin is a flavonoid compound rich in many natural plants with a wide range of pharmacological effects and nutritional value. Although previous studies have initially shown the antidepressant effect of quercetin in some models. However, the exact mechanism of the antidepressant effect of quercetin on the depression model induced by chronic unpredictable mild stress (CUMS) is still unclear or has not been clearly elucidated. The present study aimed to investigate the antidepressant effect of quercetin in vivo on a CUMS-induced depression model that is closest to human depression, and to explore its mechanism of action around nuclear factor-E2-related factor 2 (Nrf2) related signaling pathways, for the first time. Our results demonstrated that CUMS for 21 consecutive days caused significant decreases in the sucrose preference, and the horizontal score and vertical score in the open field test of mice respectively by 22.6%, 34.4%, and 66.6% (all P < 0.01), and a significant increase in the immobility time during the forced swimming test by 110.5% (P < 0.01), but fortunately, after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 26.2%, 40.1%, 152.7%, 43.5% (all P < 0.01). Further western blot analysis showed that CUMS caused the phosphorylation or expression levels of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), Nrf2 and heme oxygenase-1 (HO-1) proteins in the hippocampus of mice to significantly down-regulate by 60.0%, 72.1%, 90.0% and 50.1% (all P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of these proteins were significantly up-regulated by 85.8%, 182.0%, 325.1% and 60.3% (all P < 0.01). In addition, CUMS also caused significant reduction in the levels of antioxidants including superoxide dismutase (SOD) and glutathione-s transferase (GST) in the mice hippocampus by 51.3%, 40.3% (both P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 69.2% and 49.5% (both P < 0.01), as well as significant elevation in the levels of lipid peroxide malondialdehyde (MDA), inflammation medium nitric oxide (NO) and inducible nitric oxide synthase (iNOS) by 156.4%, 255.4% and 72.7% (all P < 0.01), while after chronic oral administration of high dose quercetin at 40 mg/kg, the abnormalities of the above indicators were significantly reversed by 45.9%, 26.8% and 55.2% (all P < 0.01). The medium dose of quercetin (20 mg/kg) only reversed some of the above indicators, while the low dose of quercetin (10 mg/kg) had no reversal effect on the above indicators. Collectively, the present study confirmed for the first time that quercetin weakened CUMS-induced depression in vivo, and its mechanism was at least partially attributable to the upregulation of hippocampal Nrf2 and the inhibition of iNOS, thereby correcting the central inflammatory response, and the imbalance between oxidation and antioxidant.

Influence of the inflammasome complex on psychiatric disorders: clinical and preclinical studies

INTRODUCTION

The innate immune complex, an inflammasome complex, has a role in the etiology of psychiatric disorders. Preclinical studies have demonstrated that the inflammasome activation leads to psychiatric disorders and clinical studies have proved that specific psychiatric illnesses are associated with aberrant levels of inflammatory cytokines and inflammasome. The inflammasome complex could be a major factor in the progression and pathology of psychiatric disorders.

AREA COVERED

We discuss the pathogenesis of psychiatric disorders with respect to the activation of the inflammasome complex. Inflammasome-associated inflammatory cytokines are observed in patients and animal models of psychiatric disorders. The article also reflects on inflammasome regulatory options for the prevention and treatment of psychiatric disorders. Relevant literature available on PubMed from 1992 to 2021 has been included in this review.

EXPERT OPINION

Modulating the inflammasome complex is a potential therapeutic strategy to treat symptom severity for patients with psychiatric disorders, particularly those with inflammasome-associated disorders. However, the nature of the psychiatric disorders should be considered when targeting inflammasome.

Alterations in plasma kynurenine pathway metabolites in children and adolescents with bipolar disorder and unaffected offspring of bipolar parents: A preliminary study

BACKGROUND

There has been growing scientific evidence in recent years that bipolar disorder (BD) is associated with alterations in the kynurenine (KYN) pathway. However, many of these studies have been limited by their focus on adults. Thus, this preliminary study investigated differences in the peripheral levels of KYN metabolites in children and adolescents with BD, unaffected offspring of parents with BD, and healthy controls (HCs).

METHODS

Plasma samples were collected from 49 youths with BD, 19 bipolar offspring, and 31 HCs. Tryptophan (TRP), KYN, and kynurenic acid (KYNA) were separated using electrospray ionization.

RESULTS

One-Way ANCOVA after controlling for age, gender, race, BMI-for-age, and smoking status showed that BD had lower levels of KYN, while unaffected high-risk offspring subjects had lower levels of TRP, KYN, and KYNA when compared to HCs. Moreover, we found that KYN, KYN/TRP, and KYNA/KYN levels predicted the severity of depressive symptoms, while the YMRS score was not associated with any metabolite.

CONCLUSIONS

In summary, this preliminary study has shown that KYN metabolites are decreased in both affected and unaffected subjects, strengthening the idea that the KYN pathway might underlie the familial risk of BD shown by high-risk offspring individuals. However, longitudinal studies are needed to examine whether the alterations observed in this study represent early markers of risk for later developing BD.

The role of soluble epoxide hydrolase and its inhibitors in depression

Evidence suggests that around 30 % of patients with depression do not respond to antidepressant treatment, with most of them having sub-chronic levels of inflammation. Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, which metabolize cytochrome P (CYP)-derived epoxy fatty acids to their corresponding diols. Accumulating evidence suggests that sEH plays a key role in the anti-inflammatory properties exerted by the metabolism of omega-3 polyunsaturated fatty acids (ω-3 PUFAs). Crucial evidence demonstrates that protein expression of sEH in the brain of mice experiencing depressive-like behaviour, as well as in patients with major depressive disorder is higher than in controls. Of note, treatment with sEH inhibitors exert anti-inflammatory, neurogenic and antidepressant-like effects in pre-clinical models of depression. In this review, the author discusses the role of sEH in the metabolism of ω-3 PUFAs in the context of depression, and the clinical value of sEH inhibitors as alternative therapeutic strategies for patients suffering from this condition.

Evaluating the Relationship Between Depression and Cognitive Function Among Children and Adolescents with HIV in Zambia

Depression is common among people living with HIV. Multiple studies demonstrate a link between depression and cognitive dysfunction in adults with HIV, but the association has been minimally investigated in children and adolescents with HIV in Africa. We conducted a cross-sectional analysis as part of the HIV-associated Neurocognitive Disorders in Zambia study, a prospective cohort study in Lusaka, Zambia. We included 208 perinatally-infected children with HIV ages 8-17 taking antiretroviral therapy and 208 HIV-exposed uninfected (HEU) controls. Cognition was assessed with a comprehensive neuropsychological battery. Depressive symptoms were evaluated using self-report and parent-report versions of the NIH Toolbox Sadness module and the Patient Health Questionnaire-9 (PHQ-9). Risk factors for depression and associations between depressive symptoms and cognition were evaluated in bivariable and multivariable regression models. Participants with HIV demonstrated higher levels of depressive symptoms than controls (mean NIH Toolbox Sadness T-Score 50 vs. 44, p < 0.01; mean PHQ-9 score 2.0 vs. 1.5, p = 0.03), and were more likely to have cognitive impairment (30% vs. 13%, p < 0.001). Risk factors for depressed mood included self-reported poor health (OR 7.8, p < 0.001) and negative life events (OR 1.3, p = 0.004) Depressed mood was associated with cognitive impairment in participants with HIV (OR = 2.9, 95% CI 1.2-7.2, p = 0.02) but not in HEU participants (OR 1.7, 95% CI 0.18-15.7, p = 0.6). In conclusion, depressed mood is common among youth with HIV in Zambia, and is associated with cognitive impairment. Depression may be a result of HIV-related stress and stigma, or may be part of the spectrum of HIV-associated neurocognitive disorders. The causal relationship between depressed mood and cognitive impairment is unclear and should be evaluated in future longitudinal studies.

Xanthohumol Attenuates Lipopolysaccharide-Induced Depressive Like Behavior in Mice: Involvement of NF-κB/Nrf2 Signaling Pathways

Depression is the most common psychiatric disorder associated with brain and immune system abnormalities. In recent years, xanthohumol (Xn) a bioactive prenylated flavonoid has received ample attention for its polypharmacological effects, therefore, here we aimed to explore the protective effects of Xn against the LPS-induced depressive-like symptoms mediated by inflammation and oxidative stress. We tested the effect of Xn against LPS-induced behavioural changes in mice by means of forced swimming test (FST), tail suspention test (TST), sucrose preference test (SPT) and open field test (OPT). Examined the neuroinflammation and oxido-nitrosative stress (O&NS) markers and analyze Nrf2 and NF-κB signalling pathways in the hippocampus. Our results indicated that peripheral repeated administration of lipopolysaccharides (LPS) (1 mg/kg, intra peritoneally) induced depressive-like behavior, neuroinflammation and O&NS in mice. Pretreatment with Xn (10 and 20 mg/kg, intra gastrically) reverse the behavioural impairments prophylactically as obvious in the FST and TST without effecting locomotion, however only 20 mg dose improve anhedonic behavior as observed in SPT. Similarly, Xn pretreatment in dose-dependent manner prevented the LPS induced neuro-inflammation and O&NS. Immunofluorescence analysis showed that Xn reduced activated gliosis via attenuation of Iba-1 and GFAP in hippocampus. In addition, Xn considerably reduced the expression of phospho-NF-κB and cleaved caspase-3 while enhanced Nrf2 and HO-1 expression in the hippocampus. To the best of our knowledge, this is the first study to examine the underlying beneficial prophylactic effects of the Xn in neuroinflammation and O&NS mediating depressive-like behaviors.

Adolescent stress sensitizes the adult neuroimmune transcriptome and leads to sex-specific microglial and behavioral phenotypes

Adolescent exposure to chronic stress, a risk factor for mood disorders in adulthood, sensitizes the neuroinflammatory response to a subsequent immune challenge. We previously showed that chronic adolescent stress (CAS) in rats led to distinct patterns of neuroimmune priming in adult male and female rats. However, sex differences in the neuroimmune consequences of CAS and their underlying mechanisms are not fully understood. Here we hypothesized that biological sex would dictate differential induction of inflammation-related transcriptomic pathways and immune cell involvement (microglia activation and leukocyte presence) in the hippocampus of male and female rats with a history of CAS. Adolescent rats underwent CAS (six restraint and six social defeat episodes during postnatal days 38-49), and behavioral assessments were conducted in adolescence and adulthood. Neuroimmune measures were obtained following vehicle or a systemic lipopolysaccharide (LPS) challenge in adulthood. CAS led to increased time in the corners of the open field in adolescence. In males, CAS also increased social avoidance. As adults, CAS rats displayed an exaggerated enrichment of the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway and chemokine induction following LPS challenge, and increased number of perivascular CD45⁺ cells in the hippocampus. However, CAS females, but not males, showed exaggerated glucocorticoid receptor (GR) pathway enrichment and increased microglial complexity. These results provide further insight to the mechanisms by which peripheral immune events may influence neuroimmune responses differentially among males and females and further demonstrate the importance of adolescent stress in shaping adult responses.

The functional polymorphisms linked with interleukin-1β gene expression are associated with bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a severe psychiatric illness attributable to multifactorial risk components (e.g. environmental stimuli, neuroinflammation, etc.), and genetic variations affecting these risk components are considered pivotal predisposing factors. The interleukin-1β (IL-1β) gene and its protein product have been repeatedly highlighted in the pathogenesis of BD. As functional polymorphisms and haplotypes linked with IL-1β mRNA expression have been reported, whether they are correlated with the risk of developing BD remains to be tested.

METHODS

To examine whether variations in the IL-1β gene locus confer genetic risk of BD, we recruited 930 BD patients and 912 healthy controls for the current study. All subjects were Han Chinese, and were age- and gender-matched. We tested seven functional single nucleotide polymorphisms (SNPs) spanning the IL-1β gene and one haplotype composed of three SNPs for their associations with risk of BD.

RESULTS

We found that the functional SNPs in the promoter region of IL-1β gene were significantly associated with risk of BD. The haplotype analyses further supported the involvement of IL-1β promoter SNPs in BD. The BD risk SNPs in our study have been previously reported to predict higher IL-1β levels in the brain and peripheral blood, which is consistent with the clinical observation of elevated IL-1β levels in the lymphocytes or peripheral blood of patients with BD compared with healthy subjects.

CONCLUSION

Our results support the contention that IL-1β is likely a risk gene for BD, and further investigations on this gene may promote our understanding and clinical management of this illness.

Inflammation-Related Changes in Mood Disorders and the Immunomodulatory Role of Lithium

Mood disorders are chronic, recurrent diseases characterized by changes in mood and emotions. The most common are major depressive disorder (MDD) and bipolar disorder (BD). Molecular biology studies have indicated an involvement of the immune system in the pathogenesis of mood disorders, and showed their correlation with altered levels of inflammatory markers and energy metabolism. Previous reports, including meta-analyses, also suggested the role of microglia activation in the M1 polarized macrophages, reflecting the pro-inflammatory phenotype. Lithium is an effective mood stabilizer used to treat both manic and depressive episodes in bipolar disorder, and as an augmentation of the antidepressant treatment of depression with a multidimensional mode of action. This review aims to summarize the molecular studies regarding inflammation, microglia activation and energy metabolism changes in mood disorders. We also aimed to outline the impact of lithium on these changes and discuss its immunomodulatory effect in mood disorders.

Alterations in 'inflammatory' pathways in the rat prefrontal cortex as early biological predictors of the long-term negative consequences of exposure to stress early in life

Early life stress, especially when experienced during the first period of life, affects the brain developmental trajectories leading to an enhanced vulnerability for stress-related psychiatric disorders later in life. Although both clinical and preclinical studies clearly support this association, the biological pathways deregulated by such exposure, and the effects in shaping the neurodevelopmental trajectories, have so far been poorly investigated. By using the prenatal stress (PNS) model, a well-established rat model of early life stress, we performed transcriptomic analyses in the prefrontal cortex of rats exposed or not to PNS and sacrificed at different postnatal days (PNDs 21, 40, 62). We first investigated the long-lasting mechanisms and pathways affected in the PFC. We have decided to focus on the prefrontal cortex because we have previously shown that this brain region is highly sensitive to PNS exposure. We found that adult animals exposed to PNS show alterations in 389 genes, mainly involved in stress and inflammatory signalling. We then wanted to establish whether PNS exposure could also affect the neurodevelopmental trajectories in order to identify the most critical temporal window. We found that PNS rats show the most significant changes during adolescence (between PND 40 versus PND 21), with alterations of several pathways related to stress, inflammation and metabolism, which were maintained until adulthood.

Higher levels of serum IL-1β and TNF-α are associated with an increased probability of major depressive disorder

Major depressive disorder (MDD) is a debilitating psychiatric disease. The dysregulated cytokines in depression are assumed due to the hyperactivation of the immune system. Here we aimed to evaluate the serum interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in MDD. This study recruited 87 MDD patients and 87 age and sex-matched healthy controls (HCs). The increased levels of serum IL-1β and TNF-α were observed among MDD patients. These higher levels of peripheral markers were positively correlated with the severity of depression. Therefore, the elevated levels of serum IL-1β and TNF-α might be used as risk assessment indicators for depression.

Depression and inflammation among children and adolescents: A meta-analysis

BACKGROUND

Increasing evidence suggests that youth with Major Depressive Disorder (MDD) exhibit early indicators of cardiovascular disease. A leading hypothesized mechanism of this association is via inflammatory pathways, however, results examining this direct association are mixed. Our objective was to synthesize and quantify observational studies examining the association of depression and inflammation among children and adolescents.

METHODS

Electronic searches were conducted in MEDLINE, Embase, PsycINFO, and Scopus, yielding 2,757 non-duplicate records from 1946 to 2019. The included studies measured depression or depressive symptoms and examined its association with inflammation in participants younger than 18 years. All relevant articles were reviewed and data extracted by two independent coders. Estimates were examined by using random-effects meta-analysis.

RESULTS

Twenty-two studies (20,791 participants) were included. Significant associations were observed between concurrent depression and CRP (n = 7; r = 0.12; 95% confidence interval [CI] = 0.04 to 0.19), and IL-6 (n = 7; r = 0.17; 95% CI= 0.10 to 0.24). Longitudinal analyses revealed that depression is a significant predictor of IL-6 (n = 3; r = 0.29; 95% CI= 0.04 to 0.50) and conversely, that inflammation (measured by CRP or IL-6) predicts future depression (n = 4; r = 0.04; 95% CI= 0.00 to 0.08).

LIMITATIONS

Results are limited by the small number of studies preventing examination of some moderator variables. Findings are correlational, not causal.

CONCLUSION

Depression is positively associated with concurrent and future inflammation among children and adolescents. Results suggest that bidirectional associations may exist between depression and a pro-inflammatory state.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.

Effects of adjunctive inflammatory modulation on IL-1β in treatment resistant bipolar depression

BACKGROUND

Adjunctive inflammatory modulation improved remission rates in treatment-resistant bipolar depression (TRBDD), but reliable biomarkers must be established to characterize the biosignature of TRBDD and the mechanisms underlying treatment response. In this molecular profiling study, we describe TRBDD and treatment response from the standpoint of interleukin-1 Beta (IL-1β) and KYN/TRP.

METHODS

47 TRBDD patients with moderately severe HAMD-17 scores were randomized to receive either escitalopram (ESC) (10 mg-40 mg daily dose range) + celecoxib (CBX) (200 mg twice daily), or ESC (10 mg-40 mg daily dose range) + placebo (PBO) (twice daily). Plasma cytokine levels were measured in both treatment arms at baseline and week 8, and in a healthy control (HC) group of subjects (N = 43) once. A linear mixed model (LMM) was applied to evaluate whether clinical outcome is related to CBX and changes to biomarkers throughout treatment. A binary logistic regression model was formulated from this series to predict both the primary outcome of treatment response to CBX, and the secondary outcome of diagnosis of TRBDD using age, BMI, gender, and IL-1β at baseline.

RESULTS

Patients receiving ESC + CBX had 4.278 greater odds of responding (p = 0.021) with NNT = 3, and 15.300 times more likely to remit (p < 0.001) with NNT = 2, compared with ESC + PBO patients. Patient BMI (p = 0.003), baseline IL-1β (p = 0.004), and baseline KYN/TRP (p = 0.001) were most predictive of TRBDD diagnosis. By Week 8, responders showed a downtrend in IL-1β compared to non-responders in the ESC + CBX treatment arm. However, there was no statistical difference in the IL-1β or KYN/TRP change after treatment between placebo and ESC + CBX group responders/non-responders (p = 0.239, and p = 0.146, respectively). While baseline IL-1β was elevated in TRBDD compared to HC (p < 0.001), there was no difference in IL-1β between treatment responders at Week 8 compared to HC (p = 0.067).

CONCLUSIONS

Elevated IL-1β and low KYN/TRP at baseline are components of the TRBDD molecular signature. CBX but not baseline IL-1β or KYN/TRP predict treatment response. Change in IL-1β and KYN/TRP did not predict treatment response.

Extracellular Vesicle Biomarkers Reveal Inhibition of Neuroinflammation by Infliximab in Association with Antidepressant Response in Adults with Bipolar Depression

Accumulating evidence suggests that neuroinflammation is involved in bipolar disorder (BD) pathogenesis. The tumor necrosis factor-alpha (TNF-α) antagonist infliximab was recently reported to improve depressive symptoms in a subpopulation of individuals with BD and history of childhood maltreatment. To explore the mechanistic mediators of infliximab's effects, we investigated its engagement with biomarkers of cellular response to inflammation derived from plasma extracellular vesicles enriched for neuronal origin (NEVs). We hypothesized that infliximab, compared to placebo, would decrease TNF-α receptors (TNFRs) and nuclear factor-kappa B (NF-κB) pathway signaling biomarkers, and that history of childhood abuse would moderate infliximab's effects. We immunocaptured NEVs from plasma samples collected at baseline and at weeks 2, 6, and 12 (endpoint) from 55 participants of this clinical trial and measured NEV biomarkers using immunoassays. A subset of participants (n = 27) also underwent whole-brain magnetic resonance imaging at baseline and endpoint. Childhood physical abuse moderated treatment by time interactions for TNFR1 (χ² = 9.275, p = 0.026), NF-κB (χ² = 13.825, p = 0.003), and inhibitor of NF-κB (IκBα) (χ² = 7.990, p = 0.046), indicating that higher levels of physical abuse were associated with larger biomarker decreases over time. Moreover, the antidepressant response to infliximab was moderated by TNFR1 (χ² = 7.997, p = 0.046). In infliximab-treated participants, reductions in TNFR1 levels were associated with improvement of depressive symptoms, an effect not detected in the placebo group. Conversely, reductions in TNFR1 levels were associated with increased global cortical thickness in infliximab- (r = -0.581, p = 0.029), but not placebo-treated, patients (r = 0.196, p = 0.501). In conclusion, we report that NEVs revealed that infliximab engaged the TNFR/NF-κB neuro-inflammatory pathway in individuals with BD, in a childhood trauma-dependent manner, which was associated with clinical response and brain structural changes.

Sex-specific effects of developmental exposure to polychlorinated biphenyls on neuroimmune and dopaminergic endpoints in adolescent rats

Exposure to environmental contaminants early in life can have long lasting consequences for physiological function. Polychlorinated biphenyls (PCBs) are a group of ubiquitous contaminants that perturb endocrine signaling and have been associated with altered immune function in children. In this study, we examined the effects of developmental exposure to PCBs on neuroimmune responses to an inflammatory challenge during adolescence. Sprague Dawley rat dams were exposed to a PCB mixture (Aroclor 1242, 1248, 1254, 1:1:1, 20 μg/kg/day) or oil control throughout pregnancy, and adolescent male and female offspring were injected with lipopolysaccharide (LPS, 50 μg/kg, ip) or saline control prior to euthanasia. Gene expression profiling was conducted in the hypothalamus, prefrontal cortex, striatum, and midbrain. In the hypothalamus, PCBs increased expression of genes involved in neuroimmune function, including those within the nuclear factor kappa b (NF-κB) complex, independent of LPS challenge. PCB exposure also increased expression of receptors for dopamine, serotonin, and estrogen in this region. In contrast, in the prefrontal cortex, PCB exposure blunted or induced irregular neuroimmune gene expression responses to LPS challenge. Moreover, neither PCB nor LPS exposure altered expression of neurotransmitter receptors throughout the mesocorticolimbic circuit. Almost all effects were present in males but not females, in agreement with the idea that male neuroimmune cells are more sensitive to perturbation and emphasizing the importance of studying both male and female subjects. Given that altered neuroimmune signaling has been implicated in mental health and substance abuse disorders that often begin during adolescence, these results highlight neuroimmune processes as another mechanism by which early life PCBs can alter brain function later in life.