Changes in the serum levels of inflammatory cytokines in antidepressant drug-naïve patients with major depression

miR-29a-5p rescues depressive-like behaviors in a CUMS-induced mouse model by facilitating microglia M2-polarization in the prefrontal cortex via TMEM33 suppression

BACKGROUND

Depression accounts for a high proportion of neuropsychiatric disorders and is associated with abnormal states of neurons in specific brain regions. Microglia play a pivotal role in the inflammatory state during depression development; however, the exact mechanism underlying chronic mood states remains unknown. Thus, the present study aimed to determine whether microRNAs (miRNAs) alleviate stress-induced depression-like behavior in mice by regulating the expression levels of their target genes, explore the role of neuroinflammation induced by microglial activation in the pathogenesis and progression of depression, and determine whether the role of the miR-29a-5p/transmembrane protein 33 (TMEM33) axis.

METHODS

In this study, chronic unpredictable mild stress (CUMS) mouse depression model, various behavioral tests, western blotting, dual-luciferase reporter assay, enzyme-linked immunosorbent assay, real-time quantitative reverse transcription PCR, immunofluorescence and lentivirus-mediated gene transfer were used.

RESULTS

After exposure to the CUMS paradigm, miR-29a-5p was significantly down-regulated. This downregulation subsequently promoted the polarization of microglia M1 by upregulating the expression of TMEM33, resulting in enhanced inflammatory chemokines affecting neurons. Conversely, the upregulation of miR-29a-5p within the prefrontal cortex (PFC) suppressed TMEM33 expression, facilitated microglia M2-polarization, and ameliorated depressive-like behavior.

LIMITATIONS

Only rodent models of depression were used, and human samples were not included.

CONCLUSIONS

The results of this study suggest that miR-29a-5p deficits within the PFC mediate microglial anomalies and contribute to depressive-like behaviors. miR-29a-5p and TMEM33 may, therefore, serve as potential therapeutic targets for the treatment of depression.

Antidepressant effect of PT-31, an α₂-adrenoceptor agonist, on lipopolysaccharide-induced depressive-like behavior in mice

Increasing evidence indicates that neuroinflammation, oxidative stress, and neurotrophic factors play a key role in the pathophysiology of major depressive disorder (MDD). In addition, the attenuation of inflammatory response has been considered a putative mechanism for MDD treatment. PT-31 is an imidazolidine derivative and a putative α₂-adrenoceptor agonist that has previously demonstrated antinociceptive activity. The present study aimed to investigate the effect of PT-31 on depressive-like behavior and lipopolysaccharide-induced neurochemical changes. To this end, mice received intraperitoneally saline or lipopolysaccharide (600 µg/kg), and 5 h postinjection animals were orally treated with saline, PT-31 (3, 10, and 30 mg/kg), or fluoxetine (30 mg/kg). Mice were subjected to the open field test (OFT) 6 and 24 h after lipopolysaccharide administration and to the tail suspension test (TST) 24 h postlipopolysaccharide. Subsequently, animals were euthanized, and brains were dissected for neurochemical analyses. The administration of lipopolysaccharide-induced sickness- and depressive-like behaviors, besides promoting an increase in myeloperoxidase activity and a reduction in brain-derived neurotrophic factor (BDNF) levels. Noteworthy, PT-31 3 mg/kg attenuated lipopolysaccharide-induced decreased locomotor activity 6 h after lipopolysaccharide in the OFT. All tested doses of PT-31 significantly reduced the immobility time of animals in the TST and attenuated lipopolysaccharide-induced increased myeloperoxidase activity in the cortex of mice. Our results demonstrate that PT-31 ameliorates behavioral changes promoted by lipopolysaccharide in OFT and TST, which is possibly mediated by attenuation of the inflammatory response.

Nutritional Strategies in Major Depression Disorder: From Ketogenic Diet to Modulation of the Microbiota-Gut-Brain Axis

Major depressive disorder (MDD) is a leading cause of disability worldwide. While traditional pharmacological treatments are effective for many cases, a significant proportion of patients do not achieve full remission or experience side effects. Nutritional interventions hold promise as an alternative or adjunctive approach, especially for treatment-resistant depression. This review examines the potential role of nutrition in managing MDD through addressing biological deficits and modulating pathways relevant to its pathophysiology. Specifically, it explores the ketogenic diet and gut microbiome modulation through various methods, including probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation. Numerous studies link dietary inadequacies to increased MDD risk and deficiencies in nutrients like omega-3 s, vitamins D and B, magnesium, and zinc. These deficiencies impact neurotransmitters, inflammation, and other biological factors in MDD. The gut-brain axis also regulates mood, stress response, and immunity, and disruptions are implicated in MDD. While medications aid acute symptoms, nutritional strategies may improve long-term outcomes by preventing relapse and promoting sustained remission. This comprehensive review aims to provide insights into nutrition's multifaceted relationship with MDD and its potential for developing more effective integrated treatment approaches.

Cognition and gut microbiota in schizophrenia spectrum and mood disorders: A systematic review

FRILEUX, M., BOLTRI M. and al. Cognition and Gut microbiota in schizophrenia spectrum and mood disorders: a Systematic Review. NEUROSCI BIOBEHAV REV (1) 2024 Schizophrenia spectrum disorders and major mood disorders are associated with cognitive impairments. Recent studies suggest a link between gut microbiota composition and cognitive functioning. Here, we review the relationship between gut microbiota and cognition in these disorders. To do this, we conducted a systematic review, searching Cochrane Central Register of Controlled Trials, EBSCOhost, Embase, Pubmed, Scopus, and Web of Science. Studies were included if they investigated the relationship between gut microbiota composition and cognitive function through neuropsychological assessments in patients with bipolar, depressive, schizophrenia spectrum, and other psychotic disorders. Ten studies were identified. Findings underscore a link between gut dysbiosis and cognitive impairment. This relationship identified specific taxa (Haemophilus, Bacteroides, and Alistipes) as potential contributors to bolstered cognitive performance. Conversely, Candida albicans, Toxoplasma gondii, Streptococcus and Deinococcus were associated with diminished performance on cognitive assessments. Prebiotics and probiotics interventions were associated with cognitive enhancements, particularly executive functions. These results emphasize the role of gut microbiota in cognition, prompting further exploration of the underlying mechanisms paving the way toward precision psychiatry.

Inflammation and Connexin 43 profiles in the prefrontal cortex are relevant to stress susceptibility and resilience in mice

Depression is a major chronic mental illness worldwide, characterized by anhedonia and pessimism. Exposed to the same stressful stimuli, some people behave normally, while others exhibit negative behaviors and psychology. The exact molecular mechanisms linking stress-induced depressive susceptibility and resilience remain unclear. Connexin 43 (Cx43) forms gap junction channels between the astrocytes, acting as a crucial role in the pathogenesis of depression. Cx43 dysfunction could lead to depressive behaviors, and depression down-regulates the expression of Cx43 in the prefrontal cortex (PFC). Besides, accumulating evidence indicates that inflammation is one of the most common pathological features of the central nervous system dysfunction. However, the roles of Cx43 and peripheral inflammation in stress-susceptible and stress-resilient individuals have rarely been investigated. Thus, animals were classified into the chronic unpredictable stress (CUS)-susceptible group and the CUS-resilient group based on the performance of behavioral tests following the CUS protocol in this study. The protein expression of Cx43 in the PFC, the Cx43 functional changes in the PFC, and the expression levels including interleukin (IL)-1β, tumor necrosis factor-α, IL-6, IL-2, IL-10, and IL-18 in the peripheral serum were detected. Here, we found that stress exposure triggered a significant reduction in Cx43 protein expression in the CUS-susceptible mice but not in the CUS-resilient mice accompanied by various Cx43 phosphorylation expression and the changes of inflammatory signals. Stress resilience is associated with Cx43 in the PFC and fluctuation in inflammatory signaling, showing that therapeutic targeting of these pathways might promote stress resilience.

Stress, pain, anxiety, and depression in endometriosis-Targeting glial activation and inflammation

Endometriosis (EM) is a gynecological inflammatory disease often accompanied by stress, chronic pelvic pain (CPP), anxiety, and depression, leading to a diminished quality of life. This review aims to discuss the relationship between systemic and local inflammatory responses in the central nervous system (CNS), focusing on glial dysfunctions (astrocytes and microglia) as in critical brain regions involved in emotion, cognition, pain processing, anxiety, and depression. The review presents that EM is connected to increased levels of pro-inflammatory cytokines in the circulation. Additionally, chronic stress and CPP as stressors may contribute to the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, depleting the production of inflammatory mediators in the circulatory system and the brain. The systemic cytokines cause blood-brain barrier (BBB) breakdown, activate microglia in the brain, and lead to neuroinflammation. Furthermore, CPP may induce neuronal morphological alterations in critical regions through central sensitization and the activation of glial cells. The activation of glial cells, particularly the polarization of microglia, leads to the activation of the NLRP3 inflammasome and the overproduction of inflammatory cytokines. These inflammatory cytokines interact with the signaling pathways involved in neural plasticity. Additionally, persistent inflammatory conditions in the brain lead to neuronal death, which is correlated with a reduced volume of key brain regions such as the hippocampus. This review highlights the involvement of glial cells in the pathogenesis of the mental comorbidities of EM (i.e., pain, anxiety, and depression) and to discuss potential therapeutic approaches for targeting the inflammation and activation of microglia in key brain regions.

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.

A randomized, double-blinded, placebo-controlled clinical trial on Lactobacillus-containing cultured milk drink as adjuvant therapy for depression in irritable bowel syndrome

Irritable bowel syndrome (IBS) is frequently linked with coexisting mental illnesses. Our previous study discovered that 32.1% of IBS patients had subthreshold depression (SD), placing them at higher risk of developing major depression. Gut microbiota modulation through psychobiotics was found to influence depression via the gut-brain axis. However, the efficacy of lessening depression among IBS patients remains ambiguous. The study's aim was to investigate the roles of cultured milk drinks containing 109 cfu Lactobacillus acidophilus LA-5 and Lactobacillus paracasei L. CASEI-01 on depression and related variables among IBS participants with SD. A total of 110 IBS participants with normal mood (NM) and SD, were randomly assigned to one of four intervention groups: IBS-NM with placebo, IBS-NM with probiotic, IBS-SD with placebo, and IBS-SD with probiotic. Each participant was required to consume two bottles of cultured milk every day for a duration of 12 weeks. The following outcomes were assessed: depression risk, quality of life, the severity of IBS, and hormonal changes. The depression scores were significantly reduced in IBS-SD with probiotic and placebo from baseline (p < 0.001). Only IBS-SD with probiotic showed a significant rise in serotonin serum levels (p < 0.05). A significantly higher life quality measures were seen in IBS-SD with probiotic, IBS-SD with placebo, and IBS-NM with placebo (p < 0.05). All groups, both placebo and probiotic, reported significant improvement in IBS severity post-intervention with a higher prevalence of remission and mild IBS (p < 0.05). Dual strains lactobacillus-containing cultured milk drink via its regulation of relevant biomarkers, is a potential anti-depressive prophylactic agent for IBS patients at risk.

Pro-inflammatory cytokines in stress-induced depression: Novel insights into mechanisms and promising therapeutic strategies

Stress-mediated depression is one of the common psychiatric disorders with a high prevalence and suicide rate, there is a lack of effective treatment. Accordingly, effective treatments with few adverse effects are urgently needed. Pro-inflammatory cytokines (PICs) may play a key role in stress-mediated depression. Thereupon, both preclinical and clinical studies have found higher levels of IL-1β, TNF-α and IL-6 in peripheral blood and brain tissue of patients with depression. Recent studies have found PICs cause depression by affecting neuroinflammation, monoamine neurotransmitters, hypothalamic pituitary adrenal axis and neuroplasticity. Moreover, they play an important role in the symptom, development and progression of depression, maybe a potential diagnostic and therapeutic marker of depression. In addition, well-established antidepressant therapies have some relief on high levels of PICs. Importantly, anti-inflammatory drugs relieve depressive symptoms by reducing levels of PICs. Collectively, reducing PICs may represent a promising therapeutic strategy for depression.

ApoE4 dysregulation incites depressive symptoms and mitochondrial impairments in mice

Apolipoprotein E4 (ApoE4) is involved in the stress-response processes and is hypothesized to be a risk factor for depression by means of mitochondrial dysfunction. However, their exact roles and underlying mechanisms are largely unknown. ApoE4 transgenic mice (B6. Cg-ApoEtm1Unc Cdh18Tg( GFAP-APOE i4)1Hol /J) were subjected to stress (lipopolysaccharides, LPS) to elucidate the aetiology of ApoE4-induced depression. LPS treatment significantly aggravated depression-like behaviours, concurrent with neuroinflammation and impaired mitochondrial changes, and melatonin/Urolithin A (UA) + 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) reversed these effects in ApoE4 mice. Concurrently, ApoE4 mice exhibited mitophagy deficits, which could be further exacerbated by LPS stimulation, as demonstrated by reduced Atg5, Beclin-1 and Parkin levels, while PINK1 levels were increased. However, these changes were reversed by melatonin treatment. Additionally, proteomic profiling suggested mitochondria-related signalling and network changes in ApoE4 mice, which may underlie the exaggerated response to LPS. Furthermore, HEK 293T cells transfected with ApoE4 showed mitochondria-associated protein and mitophagy defects, including PGC-1α, TFAM, p-AMPKα, PINK1 and LC3B impairments. Additionally, it aggravates mitochondrial impairment (particularly mitophagy), which can be attenuated by triggering autophagy. Collectively, ApoE4 dysregulation enhanced depressive behaviour upon LPS stimulation.

Efficacy and safety of celecoxib for treatment of mild to moderate postpartum depression: a randomized, double-blind, placebo-controlled trial

PURPOSE

Evidence has demonstrated the roles of inflammatory processes in pathogenesis of depression. We aim to assess the effects of adjunctive celecoxib with cognitive behavioral therapy (CBT), an anti-inflammatory agent, in treatment of postpartum depression and on levels of Brain-derived neurotrophic factor (BDNF) and inflammatory cytokines.

METHODS

This was a randomized, double-blind, placebo-controlled trial to investigate the effects of adjunctive celecoxib with CBT on postpartum depression. Fifty outpatient women with postpartum depression, participated in this study. Patients randomly received either a celecoxib capsule twice a day or a placebo capsule twice a day for 6 weeks. Patients were assessed using the Hamilton Depression Rating Scale (HDRS) and the adverse event checklist at baseline and weeks 2, 4, and 6.

RESULTS

Patients in the celecoxib group showed a greater decline in HDRS scores from baseline to all three study time points compared to the placebo group (p = 0.12 for week 2, p = 0.001 for week 4, p < 0.001 for week 6). Rate of response to treatment was significantly higher in the celecoxib group compared to the placebo group at week 4 (60 vs 24%, p = 0.010) and week 6 (96 vs 44%, p < 0.001). Rate of remission was significantly higher in the celecoxib group compared to the placebo group at week 4 (52 vs 20%, p = 0.018) and week 6 (96 vs 36%, p < 0.001). Levels of most inflammatory markers were significantly lower in the celecoxib group compared to the placebo group at week 6. Levels of BDNF were significantly higher in the celecoxib group compared to the placebo group at week 6 (p < 0.001).

CONCLUSIONS

Findings suggest adjunctive celecoxib is an effective treatment for the improvement of postpartum depressive symptoms.

Emerging roles of SIRT1 activator, SRT2104, in disease treatment

Silent information regulator 1 (SIRT1) is a NAD+-dependent class III deacetylase that plays important roles in the pathogenesis of numerous diseases, positioning it as a prime candidate for therapeutic intervention. Among its modulators, SRT2104 emerges as the most specific small molecule activator of SIRT1, currently advancing into the clinical translation phase. The primary objective of this review is to evaluate the emerging roles of SRT2104, and to explore its potential as a therapeutic agent in various diseases. In the present review, we systematically summarized the findings from an extensive array of literature sources including the progress of its application in disease treatment and its potential molecular mechanisms by reviewing the literature published in databases such as PubMed, Web of Science, and the World Health Organization International Clinical Trials Registry Platform. We focuses on the strides made in employing SRT2104 for disease treatment, elucidating its potential molecular underpinnings based on preclinical and clinical research data. The findings reveal that SRT2104, as a potent SIRT1 activator, holds considerable therapeutic potential, particularly in modulating metabolic and longevity-related pathways. This review establishes SRT2104 as a leading SIRT1 activator with significant therapeutic promise.

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

The involvement of central and peripheral inflammation in the pathogenesis and prognosis of major depressive disorder (MDD) has been demonstrated. The increase of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-18, and TNF-α) in individuals with depression may elicit neuroinflammatory processes and peripheral inflammation, mechanisms that, in turn, can contribute to gut microbiota dysbiosis. Together, neuroinflammation and gut dysbiosis induce alterations in tryptophan metabolism, culminating in decreased serotonin synthesis, impairments in neuroplasticity-related mechanisms, and glutamate-mediated excitotoxicity. This review aims to highlight the inflammatory mechanisms (neuroinflammation, peripheral inflammation, and gut dysbiosis) involved in the pathophysiology of MDD and to explore novel anti-inflammatory therapeutic approaches for this psychiatric disturbance. Several lines of evidence have indicated that in addition to antidepressants, physical exercise, probiotics, and nutraceuticals (agmatine, ascorbic acid, and vitamin D) possess anti-inflammatory effects that may contribute to their antidepressant properties. Further studies are necessary to explore the therapeutic benefits of these alternative therapies for MDD.

Nrf2 activation rescues stress-induced depression-like behaviour and inflammatory responses in male but not female rats

BACKGROUND

Major depressive disorder (MDD) is a recurring affective disorder that is two times more prevalent in females than males. Evidence supports immune system dysfunction as a major contributing factor to MDD, notably in a sexually dimorphic manner. Nuclear factor erythroid 2-related factor 2 (Nrf2), a regulator of antioxidant signalling during inflammation, is dysregulated in many chronic inflammatory disorders; however, its role in depression and the associated sex differences have yet to be explored. Here, we investigated the sex-specific antidepressant and immunomodulatory effects of the potent Nrf2 activator dimethyl fumarate (DMF), as well as the associated gene expression profiles.

METHODS

Male and female rats were treated with vehicle or DMF (25 mg/kg) whilst subjected to 8 weeks of chronic unpredictable stress. The effect of DMF treatment on stress-induced depression- and anxiety-like behaviours, as well as deficits in recognition and spatial learning and memory were then assessed. Sex differences in hippocampal (HIP) microglial activation and gene expression response were also evaluated.

RESULTS

DMF treatment during stress exposure had antidepressant effects in male but not female rats, with no anxiolytic effects in either sex. Recognition learning and memory and spatial learning and memory were impaired in chronically stressed males and females, respectively, and DMF treatment rescued these deficits. DMF treatment also prevented stress-induced HIP microglial activation in males. Conversely, females displayed no HIP microglial activation associated with stress exposure. Last, chronic stress elicited sex-specific alterations in HIP gene expression, many of which were normalized in animals treated with DMF. Of note, most of the differentially expressed genes in males normalized by DMF were related to antioxidant, inflammatory or immune responses.

CONCLUSIONS

Collectively, these findings support a greater role of immune processes in males than females in a rodent model of depression. This suggests that pharmacotherapies that target Nrf2 have the potential to be an effective sex-specific treatment for depression.

Novel hippocampal genes involved in enhanced susceptibility to chronic pain-induced behavioral emotionality

Altered mood and psychiatric disorders are commonly associated with chronic pain conditions; however, brain mechanisms linking pain and comorbid clinical depression are still largely unknown. In this study, we aimed to identify whether key genes/cellular mechanisms underlie susceptibility/resiliency to development of depressive-like behaviors during chronic pain state. Genome-wide RNA-seq analysis was used to examine the transcriptomic profile of the hippocampus, a limbic brain region that regulates mood and stress responses, from male rats exposed to chronic inflammatory pain. Pain-exposed animals were separated into either 'resilient' or 'susceptible' to development of enhanced behavioral emotionality based on behavioral testing. RNA-seq bioinformatic analysis, followed by validation using qPCR, revealed dysregulation of hippocampal genes involved in neuroinflammation, cell cycle/neurogenesis and blood-brain barrier integrity. Specifically, ADAM Metallopeptidase Domain 8 (Adam8) and Aurora Kinase B (Aurkb), genes with functional roles in activation of the NLRP3 inflammasome and microgliosis, respectively, were significantly upregulated in the hippocampus of 'susceptible' animals expressing increased behavioral emotionality. In addition, genes associated with blood-brain barrier integrity, such as the Claudin 4 (Cldn4), a tight junction protein and a known marker of astrocyte activation, were also significantly dysregulated between 'resilient' or 'susceptible' pain groups. Furthermore, differentially expressed genes (DEGs) were further characterized in rodents stress models to determine whether their hippocampal dysregulation is driven by common stress responses vs. affective pain processing. Altogether these results continue to strengthen the connection between dysregulation of hippocampal genes involved in neuroinflammatory and neurodegenerative processes with increased behavioral emotionality often expressed in chronic pain state.

Differences in bacterial taxa between treatment-naive patients with major depressive disorder and non-affected controls may be related to a proinflammatory profile

BACKGROUND

Major depressive disorder (MDD) is characterized by sadness and anhedonia, but also physical symptoms such as changes in appetite and weight. Gut microbiota has been hypothesized to be involved in MDD through gut-brain axis signaling. Moreover, antidepressants display antibacterial properties in the gastrointestinal tract. The aim of this study was to compare the gut microbiota and systemic inflammatory profile of young patients with MDD before and after initiation of antidepressant treatment and/or psychotherapy in comparison with a non-depressed control group (nonMDD).

METHODS

Fecal and blood samples were collected at baseline and at follow-up after four and twelve weeks, respectively. Patients started treatment immediately after collection of the baseline samples. The gut microbiota was characterized by 16 S rRNA gene sequencing targeting the hypervariable V4 region. Plasma levels of 49 unique immune markers were assessed using Mesoscale.

RESULTS

In total, 27 MDD patients and 32 nonMDD controls were included in the study. The gut microbiota in the baseline samples of MDD versus nonMDD participants did not differ regarding α- or β-diversity. However, there was a higher relative abundance of the genera Ruminococcus gnavus group, and a lower relative abundance of the genera Desulfovibrio, Tyzzerella, Megamonas, Olsenella, Gordonibacter, Allisonella and Rothia in the MDD group compared to the nonMDD group. In the MDD group, there was an increase in the genera Rothia, Desulfovibrio, Gordinobacteer and Lactobacillus, while genera belonging to the Firmicutes phylum were found depleted at twelve weeks follow-up compared to baseline. In the MDD group, IL-7, IL-8 and IL-17b levels were elevated compared to the nonMDD group at baseline. Furthermore, MDI score in the MDD group was found to correlate with Bray-Curtis dissimilarity at baseline, and several inflammatory markers at both baseline and after initiation of antidepressant treatment.

CONCLUSION

Several bacterial taxa differed between the MDD group and the nonMDD group at baseline and changed in relative abundance during antidepressant treatment and/or psychotherapy. The MDD group was furthermore found to have a pro-inflammatory profile compared to the nonMDD group at baseline. Further studies are required to investigate the gut microbiota and pro-inflammatory profile of patients with MDD.

Assessing myocardial indices and inflammatory factors to determine anxiety and depression severity in patients with chronic heart failure

BACKGROUND

Patients with chronic heart failure (CHF) have a progressive disease that is associated with poor quality of life and high mortality. Many patients experience anxiety and depression (A&D) symptoms, which can further accelerate disease progression. We hypothesized that indicators of myocardial function and inflammatory stress may reflect the severity of A&D symptoms in patients with CHF. Changes in these biomarkers could potentially predict whether A&D symptoms will deteriorate further in these individuals.

AIM

To measure changes in cardiac and inflammatory markers in patients with CHF to determine A&D severity and predict outcomes.

METHODS

We retrospectively analyzed 233 patients with CHF treated at the Jingzhou Hospital, Yangtze University between 2018-2022 and grouped them according to Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) scores. We compared clinical data in the no-A&D, mild-A&D, moderate-A&D, and severe-A&D groups, the SAS and SDS scores with the New York Heart Association (NYHA) functional classification, and cardiac markers and inflammatory factors between the no/mild-A&D and moderate/severe-A&D groups. Regression analysis was performed on the markers with P < 0.05 to determine their ability to predict A&D severity in patients and the area under the receiver operating characteristic curve (AUROC) was used to evaluate their accuracy.

RESULTS

In the inter-group comparison, the following variables had an effect on A&D severity in patients with CHF: NYHA class, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, N-terminal pro-brain natriuretic peptide (NT-proBNP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (P < 0.05). Other variables did not differ significantly between the A&D groups (P > 0.05). In addition, we found that higher NYHA classes were associated with higher the SAS and SDS scores (P < 0.05). Regression analysis showed that LVEF, NT-proBNP, and IL-6 were independent risk factors for A&D severity (P < 0.05). Among them, NT-proBNP had the best predictive ability as a single indicator (AUROC = 0.781). Furthermore, the combination of these three indicators exhibited a good predictive effect toward discriminating the extent of A&D severity among patients (AUROC = 0.875).

CONCLUSION

Cardiac and inflammatory biomarkers, such as LVEF, NT-proBNP, and IL-6, are correlated with A&D severity in patients with CHF and have predictive value.

Evaluation of serum interleukin-12 and interleukin-4 as potential biomarkers for the diagnosis of major depressive disorder

Recently, scientists have focused on pro-inflammatory cytokines and immunological dysregulation in major depressive disorder (MDD). Some research suggests pro-inflammatory cytokines' role in MDD development, whereas anti-inflammatory studies are sparse. There is no systematic investigation of Bangladeshi MDD patients' pro- and anti-inflammatory cytokines. This study examines the blood levels of IL-12 and IL-4 in Bangladeshi patients and healthy controls (HCs) to determine the diagnostic accuracy of these cytokines to identify MDD patients from those without MDD. A total of 110 people with MDD from the department of psychiatry of a teaching hospital in Dhaka and 107 HCs from Dhaka participated in this case-control study. Depression and illness severity were gauged using DSM-5 criteria and Ham-D scores. Commercially marketed ELISA kits were used in accordance with manufacturer guidelines to measure the levels of IL-12 and IL-4 in peripheral blood, allowing a comparison of the patient and control groups. In comparison to HCs, MDD patients (5333.00 ± 307.40 pg/ml) showed noticeably higher levels of IL-12 than in HCs (2331.00 ± 207.40 pg/ml). The increased levels were positively correlated with Ham-D scores (male: r = 0.351, p < 0.050; female: r = 0.389, p < 0.050), suggesting a possible relationship to disease progression. Additionally, compared to HCs (272.81 ± 23.94 pg/ml), MDD patients had significantly higher peripheral blood levels of IL-4 (876.35 ± 66.73 pg/ml) (p < 0.001). Also, there was a positive correlation between IL-4 serum levels and Ham-D scores (male: r = 0.361, p < 0.050; female: r = 0.398, p < 0.050). Therefore, we observed increased levels of these serum cytokines and their association with the severity of depression. The results of this study demonstrate the possibility of IL-12 and IL-4 blood levels as distinct markers capable of differentiating between MDD patients and HCs, possibly acting as markers of MDD susceptibility. To ascertain the diagnostic effectiveness of these two cytokines, more research is necessary.

Alzheimer's Disease: Models and Molecular Mechanisms Informing Disease and Treatments

Alzheimer's Disease (AD) is a complex neurodegenerative disease resulting in progressive loss of memory, language and motor abilities caused by cortical and hippocampal degeneration. This review captures the landscape of understanding of AD pathology, diagnostics, and current therapies. Two major mechanisms direct AD pathology: (1) accumulation of amyloid β (Aβ) plaque and (2) tau-derived neurofibrillary tangles (NFT). The most common variants in the Aβ pathway in APP, PSEN1, and PSEN2 are largely responsible for early-onset AD (EOAD), while MAPT, APOE, TREM2 and ABCA7 have a modifying effect on late-onset AD (LOAD). More recent studies implicate chaperone proteins and Aβ degrading proteins in AD. Several tests, such as cognitive function, brain imaging, and cerebral spinal fluid (CSF) and blood tests, are used for AD diagnosis. Additionally, several biomarkers seem to have a unique AD specific combination of expression and could potentially be used in improved, less invasive diagnostics. In addition to genetic perturbations, environmental influences, such as altered gut microbiome signatures, affect AD. Effective AD treatments have been challenging to develop. Currently, there are several FDA approved drugs (cholinesterase inhibitors, Aß-targeting antibodies and an NMDA antagonist) that could mitigate AD rate of decline and symptoms of distress.

Neurodevelopmental and Neuropsychiatric Disorders

This chapter will focus on microglial involvement in neurodevelopmental and neuropsychiatric disorders, particularly autism spectrum disorder (ASD), schizophrenia and major depressive disorder (MDD). We will describe the neuroimmune risk factors that contribute to the etiopathology of these disorders across the lifespan, including both in early life and adulthood. Microglia, being the resident immune cells of the central nervous system, could play a key role in triggering and determining the outcome of these disorders. This chapter will review preclinical and clinical findings where microglial morphology and function were examined in the contexts of ASD, schizophrenia and MDD. Clinical evidence points out to altered microglial morphology and reactivity, as well as increased expression of pro-inflammatory cytokines, supporting the idea that microglial abnormalities are involved in these disorders. Indeed, animal models for these disorders found altered microglial morphology and homeostatic functions which resulted in behaviours related to these disorders. Additionally, as microglia have emerged as promising therapeutic targets, we will also address in this chapter therapies involving microglial mechanisms for the treatment of neurodevelopmental and neuropsychiatric disorders.

Investigating the Potential Mechanisms and Therapeutic Targets of Inflammatory Cytokines in Post-stroke Depression

Post-stroke depression (PSD) affects approximately one-third of stroke survivors, severely impacting general recovery and quality of life. Despite extensive studies, the exact mechanisms underlying PSD remain elusive. However, emerging evidence implicates proinflammatory cytokines, including interleukin-1β, interleukin-6, tumor necrosis factor-alpha, and interleukin-18, play critical roles in PSD development. These cytokines contribute to PSD through various mechanisms, including hypothalamic-pituitary-adrenal (HPA) axis dysfunction, neurotransmitter alterations, neurotrophic factor changes, gut microbiota imbalances, and genetic predispositions. This review is aimed at exploring the role of cytokines in stroke and PSD while identifying their potential as specific therapeutic targets for managing PSD. A more profound understanding of the mechanisms regulating inflammatory cytokine expression and anti-inflammatory cytokines like interleukin-10 in PSD may facilitate the development of innovative interventions to improve outcomes for stroke survivors experiencing depression.

The needle in the haystack: Identifying and validating common genes of depression, insomnia, and inflammation

BACKGROUND

Insomnia, inflammation, and depression are often co-occurring conditions. The mechanisms underlying these conditions remain unclear.

MATERIALS AND METHODS

We collected microarray datasets of depression and insomnia from GEO and analyzed them for differentially expressed genes (DEGs). We then overlapped the DEGs with a list of inflammatory response-related genes to identify genes associated with all three conditions. We next performed analyses of enrichment analyses, KEGG mapping, and protein-protein interaction to identify hub genes. Furthermore, we established a depression rat model with inflammation and insomnia to validate the potential genes. At last, a two-sample Mendelian randomization (MR) study was conducted to confirm the association of identified target genes with depression outcomes.

RESULTS

We obtained 32 common DEGs associated with the depression, insomnia and inflammatory, and found that the PI3K-AKT signaling pathway might be involved in the inflammatory response in insomnia and depression. CREB1, CYBB, FYN, and CCR5 were identified as targets for the next validation. In model rats, the CCR5 and PI3K-AKT pathways were significantly up-regulated, while the model group exhibited significantly lower hippocampal p-CREB protein expression. The MR study suggested a potential causal relationship between CREB1 and the risk of depression (OR = 1.11, p = 0.013).

LIMITATIONS

The identified potential genes and pathways require further laboratory and clinical evidence verification.

CONCLUSION

We identified four potential inflammatory related-genes (CREB1, CYBB, FYN, and CCR5). CREB1 may be a potential inflammatory response-related biomarker and drug target for depression and insomnia, as validated by the followed rat model and MR study.

Altered serum TNF-α and MCP-4 levels are associated with the pathophysiology of major depressive disorder: A case-control study results

BACKGROUND

Major Depressive Disorder (MDD) is a debilitating mental health condition with complex etiology, and recent research has focused on pro-inflammatory cytokines and chemokines as potential contributors to its pathogenesis. However, studies investigating the roles of TNF-α and MCP-4 in MDD within the Bangladeshi population are scarce. This study aimed to assess the association between serum TNF-α and MCP-4 levels and the severity of MDD, exploring their potential as risk indicators for MDD development.

METHODS

This case-control study enrolled 58 MDD patients from Bangabandhu Sheikh Mujib Medical University (BSMMU) Hospital, Dhaka, Bangladesh, alongside 30 age, sex, and BMI-matched healthy controls. MDD diagnosis followed DSM-5 criteria and disease severity using the 17-item Hamilton Depression Rating Scale (Ham-D). We measured serum TNF-α and MCP-4 levels using ELISA assays according to the supplied protocols.

RESULTS

The study revealed significantly elevated serum TNF-α levels in MDD patients (47±6.6 pg/ml, mean±SEM) compared to controls (28.06±1.07 pg/ml). These increased TNF-α levels positively correlated with Ham-D scores (Pearson's r = 0.300, p = 0.038), suggesting a potential association between peripheral TNF-α levels and MDD pathology. Additionally, MDD patients exhibited significantly higher serum MCP-4 levels (70.49±6.45 pg/ml) than controls (40.21±4.08 pg/ml). However, serum MCP-4 levels showed a significant negative correlation (r = -0.270, P = 0.048) with Ham-D scores in MDD patients, indicating a more complex role for MCP-4 in MDD pathogenesis.

CONCLUSION

This study highlights that Bangladeshi MDD patients exhibit heightened inflammatory and immune responses compared to controls, supporting the cytokine hypothesis in MDD pathogenesis. Serum TNF-α, but not MCP-4, shows promise as a potential biomarker for assessing the risk of MDD development, which could aid in early detection. Future investigations involving larger populations and longitudinal studies are essential to confirm the utility of these cytokines as biomarkers for MDD.

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.

T helper-1 activation via interleukin-16 is a key phenomenon in the acute phase of severe, first-episode major depressive disorder and suicidal behaviors

BACKGROUND

Immune-inflammatory pathways in major depressive disorder are confined to the major dysmood disorder (MDMD) phenotype (Maes et al., 2022). No studies have addressed the immune profile of first episode MDMD (FE-MDMD).

METHODS

This study investigated the immune profiles of 71 patients with the acute phase of first-episode major depressive disorder (FE-MDMD) and 40 healthy controls. We measured 48 cytokines/chemokines/growth factors, classical M1, alternative M2, T helper (Th)-1, Th-2, and Th-17 phenotypes, immune-inflammatory response system (IRS), compensatory immunoregulatory system (CIRS), and neuro-immunotoxicity profiles.

RESULTS

FE-MDMD patients show significantly activated M1, M2, Th-1, IRS, CIRS, and neurotoxicity, but not Th-2 or Th-17, profiles compared to controls. FE-MDMD is accompanied by Th-1 polarization, while there are no changes in M1/M2 or IRS/CIRS ratios. The top single indicator of FE-MDMD was by far interleukin (IL)-16, followed at a distance by TRAIL, IL-2R, tumor necrosis factor (TNF)-β. The severity of depression and anxiety was strongly associated with IRS (positively) and Th-2 (inversely) profiles, whereas suicidal behavior was associated with M1 activation. Around 56-60% of the variance in depression, anxiety, and suicidal behavior scores was explained by IL-16, platelet-derived growth factor (PDGF) (both positively), and IL-1 receptor antagonist (inversely). Increased neurotoxicity is mainly driven by IL-16, TNF-α, TRAIL, IL-6, and chemokine (CCL2, CCL11, CXCL1, CXCL10) signaling. Antidepressant-treated patients show an increased IRS/CIRS ratio as compared with drug-naïve FE-MDMD patients.

CONCLUSIONS

FE-MDMD is accompanied by positive regulation of the IRS mainly driven by Th-1 polarization and T cell activation (via binding of IL-16 to CD4), and TNF, chemokine, and growth factor signaling.

Immunity impacts cognitive deficits across neurological disorders

Cognitive deficits are a common comorbidity with neurological disorders and normal aging. Inflammation is associated with multiple diseases including classical neurodegenerative dementias such as Alzheimer's disease (AD) and autoimmune disorders such as multiple sclerosis (MS), in which over half of all patients experience some form of cognitive deficits. Other degenerative diseases of the central nervous system (CNS) including frontotemporal lobe dementia (FTLD), and Parkinson's disease (PD) as well as traumatic brain injury (TBI) and psychological disorders like major depressive disorder (MDD), and even normal aging all have cytokine-associated reductions in cognitive function. Thus, there is likely commonality between these secondary cognitive deficits and inflammation. Neurological disorders are increasingly associated with substantial neuroinflammation, in which CNS-resident cells secrete cytokines and chemokines such as tumor necrosis factor (TNF)α and interleukins (ILs) including IL-1β and IL-6. CNS-resident cells also respond to a wide variety of cytokines and chemokines, which can have both direct effects on neurons by changing the expression of ion channels and perturbing electrical properties, as well as indirect effects through glia-glia and immune-glia cross-talk. There is significant overlap in these cytokine and chemokine expression profiles across diseases, with TNFα and IL-6 strongly associated with cognitive deficits in multiple disorders. Here, we review the involvement of various cytokines and chemokines in AD, MS, FTLD, PD, TBI, MDD, and normal aging in the absence of dementia. We propose that the neuropsychiatric phenotypes observed in these disorders may be at least partially attributable to a dysregulation of immunity resulting in pathological cytokine and chemokine expression from both CNS-resident and non-resident cells.

Genotoxicity of cytokines at chemotherapy-induced 'storm' concentrations in a model of the human bone marrow

Donor cell leukaemia (DCL) is a complication of haematopoietic stem cell transplantation where donated cells become malignant within the patient's bone marrow. As DCL predominates as acute myeloid leukaemia, we hypothesized that the cytokine storm following chemotherapy played a role in promoting and supporting leukaemogenesis. Cytokines have also been implicated in genotoxicity; thus, we explored a cell line model of the human bone marrow (BM) to secrete myeloid cytokines following drug treatment and their potential to induce micronuclei. HS-5 human stromal cells were exposed to mitoxantrone (MTX) and chlorambucil (CHL) and, for the first time, were profiled for 80 cytokines using an array. Fifty-four cytokines were detected in untreated cells, of which 24 were upregulated and 10 were downregulated by both drugs. FGF-7 was the lowest cytokine to be detected in both untreated and treated cells. Eleven cytokines not detected at baseline were detected following drug exposure. TNFα, IL6, GM-CSF, G-CSF, and TGFβ1 were selected for micronuclei induction. TK6 cells were exposed to these cytokines in isolation and in paired combinations. Only TNFα and TGFβ1 induced micronuclei at healthy concentrations, but all five cytokines induced micronuclei at storm levels, which was further increased when combined in pairs. Of particular concern was that some combinations induced micronuclei at levels above the mitomycin C positive control; however, most combinations were less than the sum of micronuclei induced following exposure to each cytokine in isolation. These data infer a possible role for cytokines through chemotherapy-induced cytokine storm, in the instigation and support of leukaemogenesis in the BM, and implicate the need to evaluate individuals for variability in cytokine secretion as a potential risk factor for complications such as DCL.

Cytokine associated with severity of depressive symptoms in female nurses in Korea

Background

Depression has been associated with the risk of developing physical illnesses and diseases. Inflammatory hypotheses of immunoactive and dysregulated cytokine production have been proposed to describe this association; however, data pertaining to the high prevalence of depression among nurses are limited.

Objective

This study aimed to use a comprehensive immune-profiling approach to determine whether an abnormal profile of circulating cytokines could be identified in nurses with self-reported depression and whether this profile is associated with the severity of depression.

Methods

We investigated a cohort of 157 female nurses in Korea. The self-report Patient Health Questionnaire was used to measure the depression levels of nurses. In addition, peripheral blood samples were collected and used to measure the cytokine profile using the Luminex multiplexing system. Generalized gamma regression analyses were conducted to evaluate the association between cytokine and depressive symptoms.

Results

Regarding severity of depressive symptoms, 28.0% of nurses had moderately severe depression while 9.6% had severe depression. Moderately-severe depressive symptoms in nurses were associated with elevated levels of interleukin-6 (B = 0.460, p = 0.003), interleukin-8 (B = 0.273, p = 0.001), and interleukin-18 (B = 0.236, p = 0.023), whereas interferon-gamma levels (B = -0.585, p = 0.003) showed the opposite profile. Participants with severe depressive symptoms presented decreased interferon-gamma levels (B = -1.254, p < 0.001).

Conclusion

This study demonstrated that proinflammatory cytokines were associated with depression among nurses. This calls for early detection and intervention, considering the mechanisms linking depression to physical illness and disease.

Genetically predicted circulating levels of cytokines and the risk of depression: a bidirectional Mendelian-randomization study

Objective: Inflammatory cytokines disturbance is the main result of immune dysregulation, which is widely described in major depressive disorder (MDD). However, the potential causal relationship between these two factors has not been discovered. Therefore, the purpose of this study was to investigate the causal relationship between inflammatory cytokines and MDD risk by using the two-sample Mendelian randomization (MR) analysis. Method: Two genetic instruments obtained from publicly available gene profile data were utilized for the analysis. We obtained the genetic variation data of 41 inflammatory cytokines from genome-wide association studies (GWAS) meta-analysis of 8293 individuals of Finnish descent. The MDD data, including 135,458 MDD cases and 344,901 controls, were obtained from the Psychiatric Genomics Consortium Database. For the Mendelian randomization (MR) estimation, several methods were employed, namely, MR-Egger regression, inverse-variance weighted (IVW), weighted median, and MR-Pleiotropy RESidual Sum and Outlier (MR-PRESSO) methods. Result: A causal relationship was identified between the genetically proxied levels of Interleukin (IL) -18, IL-1β, and Regulated upon activation normal T cell expressed and secreted (RANTES) and the risk of MDD (OR = 0.968, 95%CI = 0.938, 0.998, p = 0.036; OR = 0.875, 95%CI = 0.787, 0.971, p = 0.012; OR = 0.947, 95%CI = 0.902, 0.995, p = 0.03; respectively). However, our Mendelian randomization (MR) estimates provided no causality of MDD on inflammatory cytokines. Conclusion: Our study elucidates the connection between inflammatory cytokines and MDD by using MR analysis, thereby enhancing our comprehension of the potential mechanisms. By identifying these associations, our findings hold substantial implications for the development of more effective treatments aimed at improving patient outcomes. However, further investigation is required to fully comprehend the exact biological mechanisms involved.

Inflammatory Markers in Patients With Major Depressive Disorder: A Prospective, Clinic-Based, Cohort Study From India

Background Patients with major depressive disorder have varying response rates to treatment. Multiple factors such as non-adherence, comorbidity, chronic stressors, and biological factors may be responsible for this variation. Inflammatory (pro and anti) markers have been well studied as a cause for depression, predisposing factors, and a consequence of depression. Among these, interleukins (ILs), interferons, C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) have been studied repeatedly. We conducted a pilot study to assess the levels of these inflammatory markers in patients with major depressive disorder. The specific objectives of this study were to compare and correlate changes in pro- and anti-inflammatory markers throughout different phases of depression, including pretreatment and posttreatment periods, and to evaluate the pattern of pro- and anti-inflammatory markers in patients who experienced remission or showed a positive response to treatment. Methodology This was a prospective, clinic-based, cohort study done for a period of one and a half years. Patients aged 18-65 years with depressive disorder per the International Classification of Diseases Tenth Edition and who scored more than 7 on the Hamilton Depression Rating Scale were included in this study. A total of 81 patients were recruited who were followed up till eight weeks after inclusion. A total of 31 patients completed the eight weeks of follow-up. Levels of IL-10 and TNF-α were assessed at baseline, two weeks, four weeks, and eight weeks of follow-up. Results This study tried to compare the levels of pro- and anti-inflammatory markers across pretreatment and various posttreatment phases of depression. Results showed that the levels of pro-inflammatory cytokine TNF-α increased from baseline till eight weeks of follow-up, and levels of IL-10 decreased from baseline till eight weeks of follow-up. However, these changes were not statistically significant. Conclusions This study supports the hypothesis that inflammatory markers can be trait markers of depression rather than the consequence or result.

Inulin-type oligosaccharides of Morinda officinalis exerted antidepressant effects by reducing hippocampal inflammation

Neuroinflammation contributes to the pathogenesis of depression. Inulin-type oligosaccharides of Morinda officinalis (IOMO) exert antidepressant-like effects in rodents and patients with depression, while the underlying mechanisms remain unclear. This study used chronic restraint stress (CRS) and lipopolysaccharide (LPS) to induce depression-like behaviors in mice. Western blotting and ELISA analysis were used to investigate the effects of IOMO on inflammatory cytokine levels. Immunofluorescence analysis was used to investigate the effects of IOMO on hippocampal NLRP3 inflammasome and microglial cells. The results suggested that 6 weeks of CRS induced significant depression-like behaviors based on the sucrose preference test (SPT), tail suspension test (TST), and forced swimming test (FST), which were accompanied by increases in the expression of IL-6 and the activation of hippocampal microglial cells. Chronic treatment with IOMO (25 mg/kg, i.g.) for 28 days significantly reversed these depression-like behaviors and inhibited the activation of microglial cells. Furthermore, LPS (0.5 mg/kg, i.p.) also significantly induced depression-like behaviors in the TST, FST, and novelty-suppressed feeding test (NSFT), as well as increased the expression of IL-1β and caspase-1, and activated the microglial cells and the NLRP3 inflammasome in the hippocampus. Treatment with IOMO for 9 days significantly reversed these depression-like behaviors and normalized the LPS-induced activation of the microglial cells and NLRP3 inflammasome. Taken together, these results suggested that IOMO exerted antidepressant-like effects via hippocampal microglial NLRP3 inflammasome mediation followed by caspase-1 inhibition and the production of IL-1β. These findings provide a basis for developing new antidepressants targeting the microglial NLRP3 inflammasome.

The impact of antidepressants on human neurodevelopment: Brain organoids as experimental tools

The use of antidepressants during pregnancy benefits the mother's well-being, but the effects of such substances on neurodevelopment remain poorly understood. Moreover, the consequences of early exposure to antidepressants may not be immediately apparent at birth. In utero exposure to selective serotonin reuptake inhibitors (SSRIs) has been related to developmental abnormalities, including a reduced white matter volume. Several reports have observed an increased incidence of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) after prenatal exposure to SSRIs such as sertraline, the most widely prescribed SSRI. The advent of human-induced pluripotent stem cell (hiPSC) methods and assays now offers appropriate tools to test the consequences of such compounds for neurodevelopment in vitro. In particular, hiPSCs can be used to generate cerebral organoids - self-organized structures that recapitulate the morphology and complex physiology of the developing human brain, overcoming the limitations found in 2D cell culture and experimental animal models for testing drug efficacy and side effects. For example, single-cell RNA sequencing (scRNA-seq) and electrophysiological measurements on organoids can be used to evaluate the impact of antidepressants on the transcriptome and neuronal activity signatures in developing neurons. While the analysis of large-scale transcriptomic data depends on dimensionality reduction methods, electrophysiological recordings rely on temporal data series to discriminate statistical characteristics of neuronal activity, allowing for the rigorous analysis of the effects of antidepressants and other molecules that affect the developing nervous system, especially when applied in combination with relevant human cellular models such as brain organoids.

Subsequent maternal sleep deprivation aggravates neurobehavioral abnormalities, inflammation, and synaptic function in adult male mice exposed to prenatal inflammation

OBJECTIVE

Studies have suggested that prenatal exposure to inflammation increases the risk of neuropsychiatric disorders, including anxiety, depression, and cognitive dysfunction. Because of anatomical and hormonal alterations, pregnant women frequently experience sleep dysfunction, which can enhance the inflammatory response. The aim of this study was to explore the effects of maternal sleep deprivation on prenatal inflammation exposure-induced behavioral phenotypes in offspring and identify the associated mechanisms.

METHODS

Pregnant mice received an intraperitoneal injection of lipopolysaccharide (LPS) on gestational day 15 and were subsequently subjected to sleep deprivation during gestational days 15-21. Anxiety-like behavior was evaluated by the open field test and the elevated plus maze test. Depression-like behavior was assessed by the tail suspension test and the forced swimming test. Cognitive function was determined using the Morris water maze test. The levels of markers of inflammation and synaptic function were examined employing general molecular biological techniques.

RESULTS

The results showed that prenatal exposure to LPS resulted in anxiety- and depression-like symptoms and learning and memory deficits, and these effects were exacerbated by maternal sleep deprivation. Furthermore, maternal sleep deprivation aggravated the prenatal LPS exposure-induced increase in the expression of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α and decrease in the levels of postsynaptic density-95 and synaptophysin in the hippocampus.

DISCUSSION

Collectively, these results suggested that maternal sleep deprivation exacerbates anxiety, depression, and cognitive impairment induced by prenatal LPS exposure, effects that were associated with an inflammatory response and synaptic dysfunction.

Celecoxib in Treatment of Postpartum Depression: A Case Report

Postpartum depression (PPD) impairs mother-infant interaction and has negative effects on the child's emotional, behavioral, and cognitive skills. There is considerable evidence to suggest that inflammation plays a role in the pathogenesis of depression. Controlled trials indicate that celecoxib has antidepressant effects in patients with major depressive disorder. A 34-year-old woman with mild to moderate PPD received a celecoxib capsule twice a day. This treatment has not been reported in previous studies and is novel in clinical practice. The patient was assessed using the Hamilton Depression Rating Scale (HDRS). Moreover, levels of brain-derived neurotrophic factor (BDNF) and inflammatory cytokines were measured at baseline and at the end of celecoxib therapy. This case suggests that celecoxib can improve depressive symptoms in patients with mild to moderate PPD. No adverse effects occurred during follow-up.

Human Derived Dermal Fibroblasts as in Vitro Research Tool to Study Circadian Rhythmicity in Psychiatric Disorders

A number of psychiatric disorders are defined by persistent or recurrent sleep-wake disturbances alongside disruptions in circadian rhythm and altered clock gene expression. Circadian rhythms are present not only in the hypothalamic suprachiasmatic nucleus but also in peripheral tissues. In this respect, cultures of human derived dermal fibroblasts may serve as a promising new tool to investigate cellular and molecular mechanisms underlying the pathophysiology of mental illness. In this article, we discuss the advantages of fibroblast cultures to study psychiatric disease. More specifically, we provide an update on recent advances in modeling circadian rhythm disorders using human fibroblasts.

Toxicity and Impact of Silica Nanoparticles on the Configuration of Gut Microbiota in Immunodeficient Mice

Nanoparticles (NPs), having exceptional physicochemical and electrical characteristics with lower toxicity, have evolved as dynamic drug delivery carriers in living organisms. Potentially, the intragastric gavage of silica nanoparticles (SiNPs) affects gut microbiota profiles in immunodeficient mice. In this study, the impact of SiNPs of variable size and dosage was investigated in cyclophosphamide (Cy)-induced immunodeficient mice, specifically on their immune functions and gut microbiota, through physicochemical and metagenomic analysis. SiNPs of different sizes and doses were gavaged to Cy-induced immunodeficient mice for 12 days at an interval of 24 h to investigate their effects on immunological functions and the gut microbiome of mice. Our results showed that SiNPs had no significant toxicological effects on the cellular and hematological activities of immunodeficient mice. Furthermore, after the administration of different levels of SiNPs, no immune dysfunction was found in the immunosuppressed mice groups. However, gut-microbial studies and comparisons of characteristic bacterial diversity and compositions demonstrated that SiNPs significantly affect the abundance of different bacterial communities. LEfSe analysis revealed that SiNPs significantly increased the abundance of Lactobacillus, Sphingomonas, Sutterella, Akkermansia, and Prevotella, and potentially reduced Ruminococcus and Allobaculum. Thus, SiNPs significantly regulate and modify the configuration of the gut microbiota in immunodeficient mice. These dynamic variations in the intestinal bacterial community, abundance, and diversity provide new insight into the regulation and administration of silica-based NPs. This would be helpful for the further demonstration of the mechanism of action and prediction of the potential effects of SiNPs.

Roxadustat (FG-4592) abated lipopolysaccharides-induced depressive-like symptoms via PI3K signaling

Background

Despite its role in inflammation and the redox system under hypoxia, the effects and molecular mechanisms of hypoxia-inducible factor (HIF) in neuroinflammation-associated depression are poorly explored. Furthermore, Prolyl hydroxylase domain-containing proteins (PHDs) regulate HIF-1; however, whether and how PHDs regulate depressive-like behaviors under Lipopolysaccharides (LPS)-induced stress conditions remain covered.

Methods

To highlight the roles and underlying mechanisms of PHDs-HIF-1 in depression, we employed behavioral, pharmacological, and biochemical analyses using the LPS-induced depression model.

Results

Lipopolysaccharides treatment induced depressive-like behaviors, as we found, increased immobility and decreased sucrose preference in the mice. Concurrently, we examined increased cytokine levels, HIF-1 expression, mRNA levels of PHD1/PHD2, and neuroinflammation upon LPS administration, which Roxadustat reduced. Furthermore, the PI3K inhibitor wortmannin reversed Roxadustat-induced changes. Additionally, Roxadustat treatment attenuated LPS-induced synaptic impairment and improved spine numbers, ameliorated by wortmannin.

Conclusion

Lipopolysaccharides-dysregulates HIF-PHDs signaling may contribute to neuroinflammation-coincides depression via PI3K signaling.

Inhibitory effects of fluoxetine on the secretion of inflammatory mediators and JAK/STAT3 and JNK/TLR4 gene expression

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are the most common class of medicines used for the treatment of major depression. Recent studies have reported an association between depression and inflammation and suggested the significant effects of SSRIs on inflammatory processes.

METHODS

The current study aimed to evaluate the effects of fluoxetine, an SSRI, on the level of inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), in the rat serum and RAW264.7 mouse macrophage cell line, using ELISA sandwich assays. Also, the expression of inflammatory genes, including JAK/STAT3 and TLR4/JNK, was examined in macrophages, using real-time quantitative reverse transcription PCR to determine the potential mechanism of fluoxetine in inflammation. The rats received fluoxetine (10, 20, and 40 mg/kg) 30 min before lipopolysaccharide (LPS) treatment for 90 min. The cells received different doses of fluoxetine (5, 10, and 20 µg/mL) before stimulation with LPS for 24 or 48 h.

RESULTS

The serum concentrations of IL-1β, IL-6, and TNF-α were reduced in rats and cells treated with fluoxetine. Following fluoxetine administration, the expression of JAK/STAT3 and TLR4/JNK genes was significantly decreased in the RAW264.7 cells treated with LPS for 24 h. However, after 48 h of treatment with LPS, fluoxetine failed to diminish the elevated expression of JAK and JNK genes, while it significantly decreased the expression of STAT3 and TLR4 genes.

CONCLUSION

The findings revealed that fluoxetine has anti-inflammatory properties, mainly due to the reduction of inflammatory cytokines and inhibition of JAK/STAT3 and TLR4/JNK gene expression in macrophages.

Dimensions of the Hamilton Depression Rating Scale Correlate with Impulsivity and Personality Traits among Youth Patients with Depression

The heterogeneity of symptoms in young patients with major depression disorder makes it difficult to properly identify and diagnose. Therefore, the appropriate evaluation of mood symptoms is important in early intervention. The aim of this study was to (a) establish dimensions of the Hamilton Depression Rating Scale (HDRS-17) in adolescents and young adults and (b) perform correlations between the identified dimensions and psychological variables (impulsivity, personality traits). This study enrolled 52 young patients with major depression disorder (MDD). The severity of the depressive symptoms was established using the HDRS-17. The factor structure of the scale was studied using the principal component analysis (PCA) with varimax rotation. The patients completed the self-reported Barratt Impulsiveness Scale (BIS-11) and Temperament and Character Inventory (TCI). The three dimensions of the HDRS-17 identified as core in adolescent and young patients with MDD were (1) psychic depression/motor retardation, (2) disturbed thinking, and (3) sleep disturbances/anxiety. In our study, dimension 1 correlated with reward dependence and cooperativeness; dimension 2 correlated with non-planning impulsivity, harm avoidance, and self-directedness; and dimension 3 correlated with reward dependence. Conclusions: Our study supports the previous findings, which indicate that a certain set of clinical features (including the HDRS-17 dimensions, not only total score) may represent a vulnerability pattern that characterizes patients with depression.

Evaluation of inflammatory cytokines in drug-naïve major depressive disorder: A systematic review and meta-analysis

Objective: Altered levels of peripheral inflammatory and proinflammatory cytokine markers affect the different clinical stages of major depressive disorder (MDD). A concrete understanding of the causal mechanism of MDD is a prerequisite in developing treatment strategies and preventive plans. Here we aimed to conduct an updated systematic review and meta-analysis of studies assessing the association of C-reactive protein (CRP), INF-γ, MCP-1, and TNF-α in the peripheral fluid of drug-naïve MDD patients and healthy controls (HCs). Methods: We extracted articles from PubMed, ProQuest, PsycINFO, Web of Science, and Scopus databases from inception until 14 February 2021, to find relevant studies. In this meta-analysis, we included a total of 23 eligible studies (1,366 MDD patients and 1,342 controls) in the final meta-analysis. The Cochran's chi-square Q-test and I2-index were applied to measure the heterogeneity and inconsistency of all combined results. We selected a random-effect model during the analysis and measured publication biases using the funnel plot. We performed Bonferroni adjustment for multiple testing. Results: We found a high level of TNF-α in MDD patients than in control subjects Standardized Mean Difference (SMD) with a random-effects model: 1.04, 95% CI: 0.69-1.39, z = 5.84, p < 0.001). The levels of CRP (SMD with a random-effects model: 0.18, 95% CI: -0.85-1.23, z = 0.35, p = 0.73), INF-ɤ (SMD with a random-effects model: -0.05, 95% CI: -2.72-2.62, z = 0.03, p = 0.97), and MCP-1 (SMD with a random-effects model: 0.70, 95% CI: -0.09-1.49, z = 1.73, p = 0.08) were not significantly varies between MDD patients and HCs. Conclusion: The present study findings suggest the upregulated level of peripheral TNF-α but not CRP, INF-γ, and MCP-1 involve in depression. The elevated inflammatory cytokines confirmed the inflammatory state of depression. Therefore, inflammatory cytokines might serve as potential risk assessment markers in MDD.

Introducing a depression-like syndrome for translational neuropsychiatry: a plea for taxonomical validity and improved comparability between humans and mice

Depressive disorders are the most burdensome psychiatric disorders worldwide. Although huge efforts have been made to advance treatment, outcomes remain unsatisfactory. Many factors contribute to this gridlock including suboptimal animal models. Especially limited study comparability and replicability due to imprecise terminology concerning depressive-like states are major problems. To overcome these issues, new approaches are needed. Here, we introduce a taxonomical concept for modelling depression in laboratory mice, which we call depression-like syndrome (DLS). It hinges on growing evidence suggesting that mice possess advanced socioemotional abilities and can display non-random symptom patterns indicative of an evolutionary conserved disorder-like phenotype. The DLS approach uses a combined heuristic method based on clinical depression criteria and the Research Domain Criteria to provide a biobehavioural reference syndrome for preclinical rodent models of depression. The DLS criteria are based on available, species-specific evidence and are as follows: (I) minimum duration of phenotype, (II) significant sociofunctional impairment, (III) core biological features, (IV) necessary depressive-like symptoms. To assess DLS presence and severity, we have designed an algorithm to ensure statistical and biological relevance of findings. The algorithm uses a minimum combined threshold for statistical significance and effect size (p value ≤ 0.05 plus moderate effect size) for each DLS criterion. Taken together, the DLS is a novel, biologically founded, and species-specific minimum threshold approach. Its long-term objective is to gradually develop into an inter-model validation standard and microframework to improve phenotyping methodology in translational research.

Intranasal interferon-beta alleviates anxiety and depressive-like behaviors by modulating microglia polarization in an Alzheimer's disease model

Alzheimer's disease (AD) patients frequently experience neuropsychiatric symptoms (NPS), which are linked to a lower quality of life and a faster rate of disease progression. A growing body of research indicates that several microglial phenotypes control the inflammatory response and are crucial in the pathophysiology of AD-related NPS. Given the crucial role played by inflammatory mediators produced by microglia in developing of NPS, interferon-beta (IFNβ), a cytokine with anti-inflammatory capabilities, maybe a successful treatment for NPS caused by AD. In this investigation, using a rat model of AD, we examined the impact of intranasal treatment of IFNβ on anxious/depressive-like behavior and microglial M1/M2 polarization. The rat hippocampus was bilaterally injected with lentiviruses harboring mutant human amyloid precursor protein. Rats were given recombinant IFNβ1a (68,000 IU/rat) via the intranasal route, starting on day 23 following viral infection and continuing until day 49. On days 47-49, the elevated plus maze, forced swim, and tail suspension tests were applied to measure anxiety- and depressive-like behavior. Additionally, qPCR was utilized to quantify the expression of M1 markers (CD68, CD86, and CD40) and M2 markers (Ym1, CD206, Arg1, GDNF, BDNF, and SOCS1). Our findings demonstrated that decreased M2 marker expression is accompanied by anxious/depressive-like behavior when the mutant human APP gene is overexpressed in the hippocampus. In the rat model of AD, IFNβ therapy reduces anxious/depressive-like behaviors, at least in part by polarizing microglia towards M2. Therefore, IFNβ may be a viable therapeutic drug for reducing NPS in the context of AD.

The NLRP3 inflammasome in depression: Potential mechanisms and therapies

Increasing evidence suggests that the failure of clinical antidepressants may be related with neuroinflammation. The NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome is an intracellular multiprotein complex, and has been considered as a key contributor to the development of neuroinflammation. Inhibition of NLRP3 inflammasome is an effective method for depression treatment. In this review, we summarized current researches highlighting the role of NLRP3 inflammasome in the pathology of depression. Firstly, we discussed NLRP3 inflammasome activation in patients with depression and animal models. Secondly, we outlined the possible mechanisms driving the activation of NLRP3 inflammasome. Thirdly, we discussed the pathogenetic role of NLRP3 inflammasome in depression. Finally, we overviewed the current and potential antidepressants targeting the NLRP3 inflammasome. Overall, the inhibition of NLRP3 inflammasome activation may be a potential therapeutic strategy for inflammation-related depression.

How Oxidative Stress Induces Depression?

Depression increasingly affects a wide range and a large number of people worldwide, both physically and psychologically, which makes it a social problem requiring prompt attention and management. Accumulating clinical and animal studies have provided us with substantial insights of disease pathogenesis, especially central monoamine deficiency, which considerably promotes antidepressant research and clinical treatment. The first-line antidepressants mainly target the monoamine system, whose drawbacks mainly include slow action and treatment resistant. The novel antidepressant esketamine, targeting on central glutamatergic system, rapidly and robustly alleviates depression (including treatment-resistant depression), whose efficiency is shadowed by potential addictive and psychotomimetic side effects. Thus, exploring novel depression pathogenesis is necessary, for seeking more safe and effective therapeutic methods. Emerging evidence has revealed vital involvement of oxidative stress (OS) in depression, which inspires us to pursue antioxidant pathway for depression prevention and treatment. Fully uncovering the underlying mechanisms of OS-induced depression is the first step towards the avenue, thus we summarize and expound possible downstream pathways of OS, including mitochondrial impairment and related ATP deficiency, neuroinflammation, central glutamate excitotoxicity, brain-derived neurotrophic factor/tyrosine receptor kinase B dysfunction and serotonin deficiency, the microbiota-gut-brain axis disturbance and hypothalamic-pituitary-adrenocortical axis dysregulation. We also elaborate on the intricate interactions between the multiple aspects, and molecular mechanisms mediating the interplay. Through reviewing the related research progress in the field, we hope to depict an integral overview of how OS induces depression, in order to provide fresh ideas and novel targets for the final goal of efficient treatment of the disease.

Cytokine Profiles Differentiate Symptomatic from Asymptomatic PTSD in Service Members and Veterans with Chronic Traumatic Brain Injury

Traumatic brain injuries (TBI) and posttraumatic stress disorder (PTSD) are commonly observed comorbid occurrences among military service members and veterans (SMVs). In this cross-sectional study, SMVs with a history of TBI were stratified into symptomatic and asymptomatic PTSD groups based on posttraumatic stress checklist-civilian (PCL-C) total scores. Blood-based biomarkers were assessed, and significant differential markers were associated with scores from multiple neurobehavioral self-report assessments. PCL-C cutoffs were total scores >50 (PTSD symptomatic) and <25 (asymptomatic). Cytokines IL6, IL8, TNFα, and IL10 were significantly elevated (p < 0.05−0.001) in the TBI+/PTSD symptomatic group compared to the TBI+/asymptomatic group. Cytokine levels of IL8, TNFα, and IL10 were strongly associated with PCL-C scores (0.356 < r > 0.624 for all, p < 0.01 for all), while TNFα and IL10 were additionally associated with NSI totals (r = 0.285 and r = 0.270, p < 0.05, respectively). This is the first study focused on PTSD symptom severity to report levels of circulating pro-inflammatory IL8, specifically in SMVs with TBI. These data suggest that within the military TBI population, there are unique cytokine profiles that relate to neurobehavioral outcomes associated with TBI and PTSD.

A network pharmacology approach to predict potential targets and mechanisms of "Ramulus Cinnamomi (cassiae) - Paeonia lactiflora" herb pair in the treatment of chronic pain with comorbid anxiety and depression

BACKGROUND

Traditional Chinese medicine (TCM) prescriptions have multiple bioactive properties. "Gui Zhi-Shao Yao" herb pair is widely used to treat chronic pain (CP), as well as anxiety and depression. However, its related targets and underlying mechanisms have not been deciphered.

METHODS

In this study, the network pharmacology method was used to explore the bioactive components and targets of "Gui Zhi-Shao Yao" herb pair and further elucidate its potential biological mechanisms of action in the treatment of CP with comorbid anxiety disorder (AD) and mental depression (MD).

RESULTS

Following a series of analyses, we identified 15 active compounds, hitting 130 potential targets. After the intersections the targets of this herb pair and CP, AD and MD - sorted by the value of degree - nine targets were identified as the vital ones: Akt1, IL6, TNF, PTGS2, JUN, CASP3, MAPK8, PPARγ and NOS3. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results demonstrated 11 pathways, such as AGE-RAGE signalling pathway, IL-17 signalling pathway, TNF signalling pathway, which primarily participate in the pathological processes.

CONCLUSIONS

This study preliminarily predicted and verified the pharmacological and molecular mechanisms of "Gui Zhi-Shao Yao" herb pair for treating CP with comorbid AD and MD from a holistic perspective. In vivo and in vitro experiments will be required to further investigate the mechanisms.KEY MESSAGEA network pharmacology approach was applied to identify key targets and molecular mechanisms.Nine targets were regarded as the vital targets for chronic pain with comorbid anxiety and depression.Predicted 11 pathways were the potential therapy targets and pharmacological mechanism of "Gui Zhi-Shao Yao" herb pair.

Is depression the missing link between inflammatory mediators and cancer?

Patients with cancer are at greater risk of developing depression in comparison to the general population and this is associated with serious adverse effects, such as poorer quality of life, worse prognosis and higher mortality. Although the relationship between depression and cancer is now well established, a common underlying pathophysiological mechanism between the two conditions is yet to be elucidated. Existing theories of depression, based on monoamine neurotransmitter system dysfunction, are insufficient as explanations of the disorder. Recent advances have implicated neuroinflammatory mechanisms in the etiology of depression and it has been demonstrated that inflammation at a peripheral level may be mirrored centrally in astrocytes and microglia serving to promote chronic levels of inflammation in the brain. Three major routes to depression in cancer in which proinflammatory mediators are implicated, seem likely. Activation of the kynurenine pathway involving cytokines, increases tryptophan catabolism, resulting in diminished levels of serotonin which is widely acknowledged as being the hallmark of depression. It also results in neurotoxic effects on brain regions thought to be involved in the evolution of major depression. Proinflammatory mediators also play a crucial role in impairing regulatory glucocorticoid mediated feedback of the hypothalamic-pituitary-adrenal axis, which is activated by stress and considered to be involved in both depression and cancer. The third route is via the glutamatergic pathway, whereby glutamate excitotoxicity may lead to depression associated with cancer. A better understanding of the mechanisms underlying these dysregulated and other newly emerging pathways may provide a rationale for therapeutic targeting, serving to improve the care of cancer patients.

Altered serum adiponectin and interleukin-8 levels are associated in the pathophysiology of major depressive disorder: A case-control study

BACKGROUND

Major depressive disorder (MDD) is a complex mental health condition that results in several obstacles including disabilities, loss of productivity, and economic burdens on both patients and society. Etiopathogenesis of MDD involves several factors such as sociodemographic, genetic, and biological determinants. However, any suitable biomarkers for risk assessment of depression have not been established yet. Alterations of cytokine are assumed to be involved in the pathophysiology and severity of the depressive disorder. Therefore, we aimed to evaluate serum adiponectin and interleukin-8 (IL-8) among MDD patients in Bangladesh.

METHODS

We recruited a total of 63 MDD patients and 94 age-sex matched healthy controls (HCs) in the present study. MDD patients were enrolled from a tertiary care teaching hospital, Dhaka, Bangladesh, and HCs from surrounding parts of Dhaka city. A psychiatrist assessed all the study participants following the criteria mentioned in the DSM-5. We applied the Hamilton depression (Ham-D) rating scale to assess the depression severity. Serum adiponectin and IL-8 levels were determined using ELISA kits (BosterBio, USA).

RESULTS

The mean serum concentration of adiponectin was decreased (30.67±4.43 μg/mL vs. 53.81±5.37 μg/mL), and the IL-8 level was increased (160.93±14.84 pg/mL vs. 88.68±6.33 pg/mL) in MDD patients compared to HCs. Sex-specific scatters plot graphs showed the distribution of adiponectin and IL-8 levels with Ham-D scores in MDD patients. Also, ROC curve analysis demonstrated good predictive performances of serum adiponectin and IL-8 for MDD with the area under the curve (AUC) as 0.895 and 0.806, respectively.

CONCLUSION

The present study findings suggest that alterations of serum adiponectin and IL-8 levels in MDD patients might be involved in the disease process. Therefore, we can use these changes of cytokines in serum levels as early risk assessment tools for depression. The present study findings should be considered preliminary. We propose further interventional studies to evaluate the exact role of adiponectin and IL-8 in depression.

Stress- and drug-induced neuroimmune signaling as a therapeutic target for comorbid anxiety and substance use disorders

Stress and substance use disorders remain two of the most highly prevalent psychiatric conditions and are often comorbid. While individually these conditions have a debilitating impact on the patient and a high cost to society, the symptomology and treatment outcomes are further exacerbated when they occur together. As such, there are few effective treatment options for these patients, and recent investigation has sought to determine the neural processes underlying the co-occurrence of these disorders to identify novel treatment targets. One such mechanism that has been linked to stress- and addiction-related conditions is neuroimmune signaling. Increases in inflammatory factors across the brain have been heavily implicated in the etiology of these disorders, and this review seeks to determine the nature of this relationship. According to the "dual-hit" hypothesis, also referred to as neuroimmune priming, prior exposure to either stress or drugs of abuse can sensitize the neuroimmune system to be hyperresponsive when exposed to these insults in the future. This review completes an examination of the literature surrounding stress-induced increases in inflammation across clinical and preclinical studies along with a summarization of the evidence regarding drug-induced alterations in inflammatory factors. These changes in neuroimmune profiles are also discussed within the context of their impact on the neural circuitry responsible for stress responsiveness and addictive behaviors. Further, this review explores the connection between neuroimmune signaling and susceptibility to these conditions and highlights the anti-inflammatory pharmacotherapies that may be used for the treatment of stress and substance use disorders.

Plasma levels of interleukin-8 and response to paroxetine in patients with major depressive disorder

OBJECTIVES

Immune dysregulation plays a key role in major depressive disorder (MDD). However, little is known about the complicated involvement of various interleukins in MDD. This study was performed to investigate the correlation between plasma interleukin-8 (IL-8) levels and treatment outcome of paroxetine (a selective serotonin reuptake inhibitor) in patients with MDD.

METHODS

A total of 115 hospitalized patients (36 males and 79 females), aged from 18 to 72 years, were enrolled. Plasma levels of IL-8 were measured before treatment initiation (baseline) and at 8 weeks after oral paroxetine treatment. Efficacy of paroxetine was evaluated by use of the Hamilton Depression Rating Scale (HAMD-17). Baseline IL-8 levels were compared between responders and non-responders to paroxetine treatment.

RESULTS

Plasma IL-8 levels decreased significantly after an 8-week antidepressant treatment in responders, in association with a dramatic decrease in HAMD-17 scores. In non-responders, plasma IL-8 levels did not change significantly at 8 weeks after antidepressant treatment. Baseline plasma IL-8 levels were found to be significantly lower in responders than in non-responders, showing a correlation between IL-8 and antidepressant response to paroxetine.

CONCLUSIONS

These results indicate that plasma IL-8 levels were related to treatment outcome of paroxetine, and therefore suggest that IL-8 could be a promising predicator of treatment response in individual patients with MDD.