Cytokines and major depression

Microglial cannabinoid receptor 2 and epigenetic regulation: Implications for the treatment of depression

Depression, often stress-induced, is closely related to neuroinflammation, in which microglia, the brain's immune cells, are the leading players. Microglia shift between a quiescent and an active state, promoting both pro- and anti-inflammatory responses. Cannabinoid type 2 (CB2) receptor encoded by the CNR2 gene is a key player to modulate inflammatory activity. CB2 receptor is highly controlled at the epigenetic level, especially in response to stressful stimuli, positioning it between stress, neuroinflammation, and depression. The following review addresses how epigenetic regulation of CNR2 expression affects depression and the dissection, further, of molecular pathways driving neuroinflammation-related depressive states. The present study emphasizes the therapeutic potential of CB2 receptor agonists that selectively interact with activated microglia and opens a new avenue for the treatment of depression associated with neuroinflammation. The review, therefore, provides a framework of underlying mechanisms for developing novel therapeutic strategies that focus on relieving symptoms by modulating the neuroinflammatory response. Finally, this review underlines the possibilities of therapeutic interventions taking into account CB2 receptors in combating depression.

Depression as a risk factor for Alzheimer's disease: A human post-mortem study

Depression is associated with persistent low mood. In mid to late life, it has been identified as a risk factor for Alzheimer's disease (AD) with evidence that depression might be an early manifestation of AD. Although the underlying mechanisms by which depression enhances AD development remain unknown, there are several features commonly seen in both diseases such as the presence of neuroinflammation. In this study, we aimed to identify whether neuroinflammation is increased in depression as observed in the early stages of AD by examining post-mortem human brain tissue. Post-mortem human brain tissue from 54 cases with depression and 37 controls without depression were retrieved from the Douglas Bell Canada Brain Bank. Sixteen early-stage AD cases defined as a Braak stage III-IV and 15 controls were sourced from the South West Dementia Brain Bank. Frozen tissue from the dorsal prefrontal cortex was obtained for all cases in order to measure inflammatory proteins (IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and TNF-α) and endothelial markers (ICAM-1, VCAM) using ELISA and MesoScale Multiplex Assays. In the depression group, increase of IL-6 and IL-10, and decrease of IL-1β were observed compared to controls, with no changes detected for the other cytokines and the endothelial markers. In early-stage AD cases, only increased ICAM-1 expression was found compared to controls, indicating endothelial activation as an early feature of AD. None of the cytokines measured showed alteration of their expression in early-stage AD cases. Depression, but not AD, was associated with evidence of neuroinflammation. Depression may increase AD risk through different mechanism(s) than inflammation.

The association between cytokines and cognitive function in patients with major depressive disorder and controls

BACKGROUND

Cognitive dysfunction is a symptom of depression (MDD). While the involvement of the immune system has long been suggested to contribute to the biological underpinnings of depression, less is known about the underpinnings of cognitive dysfunction. A recent genome-wide association study pointed to genes related to immune function to be relevant for cognitive processes in depression. However, only a few studies have explored immune proteins in blood in MDD who also suffer from cognitive dysfunction. In this study we investigate associations between cognitive impairment and cytokines using a comprehensive cognitive test battery and a broad cytokine assay.

METHODS

124 patients with MDD and 69 healthy controls (HC) were recruited. To assess cognition, RBANS was used, which measures immediate and delayed memory, visual-spatial functions, language and attention. Moreover, six cytokines (IL-8, IL-1beta, IL-6, IL-10; TNF-alpha and IL-12p70) were recorded. Associations were examined by regression analyses with age, sex, education, country, group and symptom severity as covariates.

RESULTS

There is an exploratory tendency that higher cytokine levels (IL-1beta, IL-6, IL-8, IL-10, IL-12p70) are associated with mostly lower cognition ("language", "visual-constructional", "attention" and "total score"). After conservative, corrected interpretation, interleukins were not statistically significant associated with poorer cognitive function.

LIMITATIONS

Despite a large sample, the unbalanced sample size is a limitation. For future studies, it is advisable to match participants based on age and gender.

CONCLUSIONS

Cognitive dysfunction could be associated with specific cytokines that underpin the contribution of the immune system, but further research is necessary.

Genistein improves depression-like behavior in rats by regulating intestinal flora and altering glutamate gene expression

Depression is a mental disorder, and genistein is known to have antidepressant effects, but its mechanism of action is still unclear. Here, the mechanism of genistein improving depression based on gut microbiota was explored using classic behavioral indicators of depression combined with genomic technology. The behavioral evaluation showed that rats gavaged with 20-40 mg/kg genistein showed an increase in body weight, glucose preference, absenteeism score, body temperature, and 5-hydroxytryptamine (5-HT) content, while a decrease in adrenocorticotropic hormone (ACTH) and corticosterone (CORT) content compared to the depression rat model group, but there was no significant difference compared to the positive control (fluoxetine). The results of high-throughput sequencing showed that genistein increased the relative abundance of Firmicutes and Actinobacteriota and decreased the relative abundance of Bacteroidota at the phylum level. At the genus level, the abundance of Bifidobacterium, a short-chain fatty acid producing bacterium, was increased. Furthermore, metagenome results revealed that the antidepressant effect of genistein can be achieved by promoting glutamate metabolism, increasing glutamic acid decarboxylase (GAD) expression levels, promoting γ-aminobutyric acid (GABA) synthesis, and indirectly increasing 5-HT levels.

Are S100B and VILIP-1 Involved in a Common Mechanism of Neuroinflammation in Major Depressive Disorder?

This study aimed to evaluate the role of neuroinflammation in neuronal and glial cells in the pathophysiology of Major Depressive Disorder (MDD) through different biomarkers.S100-B and VILIP-1 levels of patients diagnosed with MDD were evaluated before and after antidepressant treatment. A total of 65 patients diagnosed with MDD and 69 healthy controls were included. Serum levels of S100B and VILIP-1 were measured at the time of diagnosis and after eight weeks antidepressant treatment and compared with healthy controls. Hamilton Depression Rating Scale (HDRS) and the Clinical Global Impression Scale (CGI) were applied to assess the severity of depression. In our study, although serum S100B levels were higher in patients before treatment compared to healthy controls, this difference was not statistically significant. Regarding VILIP-1 levels, there was no statistically significant difference between patients and healthy controls. A positive and statistically significant correlation was found between S100B and VILIP-1 levels in MDD group before the treatment. At the eighth week of treatment, a statistically significant positive correlation was also found between S100B and VILIP-1 levels. Our research is the first study to evaluate MDD through two separate biomarkers specific to glial and neuronal cells.The fact that S100B and VILIP-1 levels showed significant correlations in patients diagnosed with MDD both before and after treatment suggests that they may play a shared role in the pathophysiology of the disorder. The correlation between S100B and VILIP-1 may serve as a guide in understanding the pathophysiology of the disorder and in identifying new drug development targets.

The interface of depression and diabetes: treatment considerations

This state-of-the-art review explores the relationship between depression and diabetes, highlighting the two-way influences that make treatment challenging and worsen the outcomes of both conditions. Depression and diabetes often co-occur and share genetic, lifestyle, and psychosocial risk factors. Lifestyle elements such as diet, physical activity, and sleep patterns play a role on the development and management of both conditions, highlighting the need for integrated treatment strategies. The evidence suggests that traditional management strategies focusing on either condition in isolation fall short of addressing the intertwined nature of diabetes and depression. Instead, integrated care models encompassing psychological support and medical management are recommended to improve treatment efficacy and patient adherence. Such models require collaboration across multiple healthcare disciplines, including endocrinology, psychiatry, and primary care, to offer a holistic approach to patient care. This review also identifies significant patient-related barriers to effective management, such as stigma, psychological resistance, and health literacy, which need to be addressed through patient-centered education and support systems. Future directions for research include longitudinal studies in diverse populations to further elucidate causal relationships and the exploration of novel therapeutic targets, as well as the effectiveness of healthcare models aimed at preventing the onset of one condition in individuals diagnosed with the other.

Ontogenetic Neuroimmune Changes Following Prenatal Alcohol Exposure: Implications for Neurobehavioral Function

This chapter reviews the enduring effects of prenatal alcohol exposure (PAE) on neuroimmune function across the lifespan, including discussion of associated neurobehavioral alterations. Alcohol has potent teratogenic effects, with a large body of work linking PAE to perturbations in neuroimmune function. These PAE-related neuroimmune disturbances may have downstream effects on neurobehavioral function given the critical role of the neuroimmune system in central nervous system development. The neuroimmune system matures over time, playing distinct roles depending on the developmental processes occurring within that maturational stage. This chapter thus takes an ontogenetic approach to understanding how PAE induces unique neuroimmune changes across the lifespan, beginning with a review of changes in early life before moving into adolescence and ending in adulthood. The focus will be on work utilizing rodent models, which allow for more tightly controlled conditions than are possible in human research. The chapter concludes with a discussion of possible mechanisms underlying the developmental changes in neuroimmune function following PAE, with a specific focus on the role of the gut microbiota.

Efficacy of Transcranial Direct Current Stimulation (tDCS) on Neuropsychiatric Symptoms in Multiple Sclerosis (MS)-A Review and Insight into Possible Mechanisms of Action

Introduction: Neuropsychiatric symptoms such as depression and anxiety are a significant burden on patients with multiple sclerosis (MS). Their pathophysiology is complex and yet to be fully understood. There is an urgent need for non-invasive treatments that directly target the brain and help patients with MS. One such possible treatment is transcranial direct current stimulation (tDCS), a popular and effective non-invasive brain stimulation technique. Methods: This mechanistic review explores the efficacy of tDCS in treating depression and anxiety in MS while focusing on the underlying mechanisms of action. Understanding these mechanisms is crucial, as neuropsychiatric symptoms in MS arise from complex neuroinflammatory and neurodegenerative processes. This review offers insights that may direct more focused and efficient therapeutic approaches by investigating the ways in which tDCS affects inflammation, brain plasticity, and neural connections. Searches were conducted using the PubMed/Medline, ResearchGate, Cochrane, and Google Scholar databases. Results: The literature search yielded 11 studies to be included in this review, with a total of 175 patients participating in the included studies. In most studies, tDCS did not significantly reduce depression or anxiety scores as the studied patients did not have elevated scores indicating depression and anxiety. In the few studies where the patients had scores indicating mild/moderate dysfunction, tDCS was more effective. The risk of bias in the included studies was assessed as moderate. Despite the null or near-null results, tDCS may still prove to be an effective treatment option for depression and anxiety in MS, because tDCS produces a neurobiological effect on the brain and nervous system. To facilitate further work, several possible mechanisms of action of tDCS have been reported, such as the modulation of the frontal-midline theta, reductions in neuroinflammation, the modulation of the HPA axis, and cerebral blood flow regulation. Conclusions: Although tDCS did not overall demonstrate positive effects in reducing depression and anxiety in the studied MS patients, the role of tDCS in this area should not be underestimated. Evidence from other studies indicates the effectiveness of tDCS in reducing depression and anxiety, but the studies included in this review did not include patients with sufficient depression or anxiety. Future studies are needed to confirm the effectiveness of tDCS in neuropsychiatric dysfunctions in MS.

The association of the comorbidity status of metabolic syndrome and cognitive dysfunction with health-related quality of life

PURPOSE

Both metabolic syndrome (MetS) and cognitive dysfunction impair health-related quality of life (HRQOL). This study aims to determine whether individuals experiencing both MetS and cognitive dysfunction have lower HRQOL.

METHODS

This cross-sectional study enrolled 567 participants who attended outpatient clinics at a medical center in northern Taiwan. MetS was diagnosed according to the modified criteria for the Asian population. Cognitive function was categorized as normal, mild cognitive dysfunction, and advanced cognitive dysfunction according to the score of the Montreal Cognitive Assessment, Taiwanese version. HRQOL was assessed using the SF-36v2® Health Survey (SF-36v2). The associations of the comorbidity status of MetS and cognitive dysfunction with HRQOL were analyzed using linear regression models, adjusting for age, sex, marital status, education level, income groups, and activities of daily living.

RESULTS

Out of 567 participants, 33 (5.8%) had MetS with mild cognitive dysfunction, and 34 (6.0%) had MetS with advanced cognitive dysfunction. Participants with both MetS and advanced cognitive dysfunction exhibited the lowest scores in the physical component summary and almost all scales of HRQOL. MetS exacerbated the inverse association between mild cognitive dysfunction and the mental component summary. For those with MetS, the scores on scales of role physical, bodily pain, vitality, and social functioning worsened as cognitive function deteriorated (all Ptrend<0.05).

CONCLUSION

As the severity of comorbidity between MetS and cognitive dysfunction varies, patients exhibited poorer performance in different aspects of HRQOL. Future research is needed to find solutions to improve HRQOL for patients with both MetS and cognitive dysfunction.

Microbiota-gut-brain axis: Natural antidepressants molecular mechanism

BACKGROUND

Major depressive disorder (MDD) is a severe mental health condition characterized by persistent depression, impaired cognition, and reduced activity. Increasing evidence suggests that gut microbiota (GM) imbalance is closely linked to the emergence and advancement of MDD, highlighting the potential significance of regulating the "Microbiota-Gut-Brain" (MGB) axis to impact the development of MDD. Natural products (NPs), characterized by broad biological activities, low toxicity, and multi-target characteristics, offer unique advantages in antidepressant treatment by regulating MGB axis.

PURPOSE

This review was aimed to explore the intricate relationship between the GM and the brain, as well as host responses, and investigated the mechanisms underlying the MGB axis in MDD development. It also explored the pharmacological mechanisms by which NPs modulate MGB axis to exert antidepressant effects and addressed current research limitations. Additionally, it proposed new strategies for future preclinical and clinical applications in the MDD domain.

METHODS

To study the effects and mechanism by which NPs exert antidepressant effects through mediating the MGB axis, data were collected from Web of Science, PubMed, ScienceDirect from initial establishment to March 2024. NPs were classified and summarized by their mechanisms of action.

RESULTS

NPs, such as flavonoids,alkaloids,polysaccharides,saponins, terpenoids, can treat MDD by regulating the MGB axis. Its mechanism includes balancing GM, regulating metabolites and neurotransmitters such as SCAFs, 5-HT, BDNF, inhibiting neuroinflammation, improving neural plasticity, and increasing neurogenesis.

CONCLUSIONS

NPs display good antidepressant effects, and have potential value for clinical application in the prevention and treatment of MDD by regulating the MGB axis. However, in-depth study of the mechanisms by which antidepressant medications affect MGB axis will also require considerable effort in clinical and preclinical research, which is essential for the development of effective antidepressant treatments.

Associations of muscle mass and strength with depression among US adults: A cross-sectional NHANES study

OBJECTIVES

The aim of our study was to assess the association between muscle mass and strength and depression through a cross-sectional study of the National Health and Nutrition Examination Survey from 2011 to 2014.

METHODS

Muscle mass was calculated by summing the lean body mass of the limbs and muscle strength was assessed by grip strength. Depression was determined by The 9-item Patient Health Questionnaire. We used weighted multivariate logistic regression models to explore the relationship between muscle mass and strength and depression. Generalized additive models were used to test for the presence of nonlinear associations. We then constructed a two-piece-wise linear regression model and performed a recursive algorithm to calculate inflection points. In addition, subgroup analyses and interaction tests were performed.

RESULTS

The study recruited 4871 adults from the United States. In regression models adjusted for all confounding variables, the OR (95 % CI) for the association between grip strength and appendicular lean mass (ALM) and depression were 0.943 (0.903, 0.985), 0.945 (0.908, 0.983), respectively. There was a non-linear association between grip strength and depression with a turning point of 46.3. The OR (95 % CI) before the turning point was 0.920 (0.872, 0.972). The interaction was statistically significant only in the age analysis. There was also a nonlinear association between ALM and depression, but no significant turning point was found. The interaction was statistically significant in the gender and BMI analyses.

CONCLUSION

Grip strength and ALM are negatively associated with an increased likelihood of depression in US adults. Exercises for muscle mass and strength may help prevent depression.

The interplay between polygenic score for tumor necrosis factor-α, brain structural connectivity, and processing speed in major depression

Reduced processing speed is a core deficit in major depressive disorder (MDD) and has been linked to altered structural brain network connectivity. Ample evidence highlights the involvement of genetic-immunological processes in MDD and specific depressive symptoms. Here, we extended these findings by examining associations between polygenic scores for tumor necrosis factor-α blood levels (TNF-α PGS), structural brain connectivity, and processing speed in a large sample of MDD patients. Processing speed performance of n = 284 acutely depressed, n = 177 partially and n = 198 fully remitted patients, and n = 743 healthy controls (HC) was estimated based on five neuropsychological tests. Network-based statistic was used to identify a brain network associated with processing speed. We employed general linear models to examine the association between TNF-α PGS and processing speed. We investigated whether network connectivity mediates the association between TNF-α PGS and processing speed. We identified a structural network positively associated with processing speed in the whole sample. We observed a significant negative association between TNF-α PGS and processing speed in acutely depressed patients, whereas no association was found in remitted patients and HC. The mediation analysis revealed that brain connectivity partially mediated the association between TNF-α PGS and processing speed in acute MDD. The present study provides evidence that TNF-α PGS is associated with decreased processing speed exclusively in patients with acute depression. This association was partially mediated by structural brain connectivity. Using multimodal data, the current findings advance our understanding of cognitive dysfunction in MDD and highlight the involvement of genetic-immunological processes in its pathomechanisms.

Possible roles of neuropeptide/transmitter and autoantibody modulation in emotional problems and aggression

The theoretical foundations of understanding psychiatric disorders are undergoing changes. Explaining behaviour and neuroendocrine cell communication leaning towards immunology represents a different approach compared to previous models for understanding complex central nervous system processes. One such approach is the study of immunoglobulins or autoantibodies, and their effect on peptide hormones in the neuro-endocrine system. In the present review, we provide an overview of the literature on neuropeptide/transmitter and autoantibody modulation in psychiatric disorders featuring emotional problems and aggression, including associated illness behaviour. Finally, we discuss the role of psycho-immunology as a growing field in the understanding of psychiatric disorders, and that modulation and regulation by IgG autoAbs represent a relatively new subcategory in psycho-immunology, where studies are currently being conducted.

Peripheral CD4+ T helper lymphocytes alterations in major depressive disorder: A systematic review and meta-analysis

Previous research has shown that patients with major depressive disorder (MDD) develop immune dysfunction. However, the exact alterations of cluster of differentiation (CD)4+ T helper (Th) lymphocytes in MDD remains unclear. This meta-analysis aimed to examine the specific changes in CD4+ Th cells. A comprehensive search of PubMed, EMBASE, Web of Science, and PsycINFO databases was conducted to identify studies investigating CD4+ Th, Th1, Th2, Th17, and T regulatory (Treg) cell counts in the peripheral blood of MDD patients and healthy controls (HCs), covering the period up to June 22, 2024. Our findings revealed that patients with MDD might exhibit higher CD4+ Th cells (SMD=0.26, 95 %CI, 0.02 to 0.50), CD4+/CD8+ cell ratios (SMD=0.51, 95 %CI, 0.14 to 0.89), Th1/Th2 cell ratios (SMD=0.15, 95 %CI, 0.01 to 0.30) and lower Th1 (SMD=-0.17, 95 %CI, -0.30 to -0.03), Th2 (SMD=-0.25, 95 %CI, -0.40 to -0.11), and Treg cells (SMD=-0.69, 95 %CI, -1.27 to -0.11). However, no significant difference was observed in terms of Th17 cells and Th17/Treg cell ratios between MDD patients and the HCs. Heterogeneity was large (I2:18.1-95.2 %), and possible sources of heterogeneity were explored (e.g., age, depression scale, country, and antidepressant use). Our findings indicate that peripheral CD4+ T cells in depressed patients exhibit features of adaptive immune dysfunction, as evidenced by increased CD4+ Th cells and CD4+/CD8+ and decreased Treg cells. These findings offer insights into the underlying mechanism of MDD.

Effects of chronic intermittent cold stress on anxiety-depression-like behaviors in adolescent rats

Stress, which triggers numerous physiological and behavioral responses in the organism, is a significant risk factor that contributes to the development of psychiatric disorders such as depression and anxiety. This study aimed to investigate the inflammation, oxidative stress status, anxiety, and depression-like behaviors of adolescent rodents exposed to chronic intermittent cold stress. Adolescent male rats were subjected to a modified chronic intermittent cold stress model (21 days, 1 hour/day, 4 °C). Depression-like behaviors were evaluated using the sucrose preference and forced swimming tests, while anxiety-like behaviors were assessed using the open field, elevated plus maze, and light-dark box tests. We measured levels of cortisol, tumor necrosis factor-α, interleukin-1β, brain-derived natriuretic factor, reactive oxygen species, malondialdehyde, total oxidants and antioxidants, and other chemicals in the prefrontal cortex, thalamus, striatum, and hippocampus brain regions of rats using ELISA and colorimetric methods. Data were analyzed using Student's t-test and Pearson correlation analysis. After the cold stress treatment, both anxiety and depression-like behaviors increased remarkably in the subjects. Our study revealed significant changes in various brain regions among the stress-exposed subjects. Cold stress resulted in decreased BDNF levels in the prefrontal cortex and striatum (p < 0.05), increased cortisol levels in the prefrontal cortex (p < 0.05), increased IL-1β levels in the hippocampus and thalamus (p < 0.05), increased protein carbonyl levels in the striatum (p < 0.05), and decreased TAS in the prefrontal cortex and thalamus (p < 0.05). Adolescent rats exposed to cold exhibit both anxiety- and depression-like behaviors. This study observed an increase in inflammation in various brain regions, yet the responses to stress varied. Our findings suggest that adolescence is a period of heightened sensitivity to stress, which can lead to dramatic consequences.

Psychological Aspects of Cutaneous Pain in Psoriasis

Introduction: Psoriasis is a chronic inflammatory disease that negatively impacts patients' quality of life (QoL) and mental health. Itch and pain are prevalent symptoms of psoriasis and contribute to the psychosocial burden of this disease. This study aimed to evaluate the impact of skin pain on the prevalence and severity of symptoms of anxiety and depression and on the QoL in psoriasis patients. Methods: The studied population comprised 106 adults with psoriasis (34% female; mean age 42.1 ± 13.0 years). Disease severity was measured with the Psoriasis Area and Severity Index (PASI). The intensity of skin pain was assessed with the NRS and the Short Form McGill Pain Questionnaire (SF-MPQ). The Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) questionnaires were used to estimate the severity of depression and anxiety, respectively, as was the Hospital Anxiety and Depression Scale (HADS). Quality of life (QoL) was studied using the Dermatology Life Quality Index (DLQI). Results: Regarding anxiety assessment, females reported significantly higher scores with the HADS-A (8.42 ± 4.85 points vs. 5.14 ± 3.9 points; p < 0.001) and the GAD-7 compared to men (7.50 ± 5.58 points vs. 5.24 ± 4.79 points; p = 0.036). Similarly, the severity of depression was significantly higher in women, as measured with the PHQ-9 (7.50 ± 5.58 points vs. 5.24 ± 4.79 points, p = 0.021). Psoriasis patients with skin pain scored significantly higher in HADS Total score (p = 0.043), HADS-A (p = 0.022), PHQ-9 (p = 0.035), and DLQI (p < 0.001) than the rest of the studied group. The intensity of skin pain measured with the SF-MPQ correlated significantly with HADS Total score (p = 0.021), HADS-A (p < 0.001), HADS-D (p = 0.038), and PHQ-9 (p < 0.001). Additionally, there was a significant correlation between the intensity of cutaneous pain assessed using the VAS and the PHQ-9 (p = 0.022). Conclusions: Skin pain significantly influences the well-being of patients with psoriasis as well as the symptoms of anxiety and depression. In particular, women with psoriasis are at increased risk of developing anxiety and depression. Our findings underline the necessity for a multidisciplinary approach to the management of this dermatosis.

Ghrelin/GHSR System in Depressive Disorder: Pathologic Roles and Therapeutic Implications

Depression is the most common chronic mental illness and is characterized by low mood, insomnia, and affective disorders. However, its pathologic mechanisms remain unclear. Numerous studies have suggested that the ghrelin/GHSR system may be involved in the pathophysiologic process of depression. Ghrelin plays a dual role in experimental animals, increasing depressed behavior and decreasing anxiety. By combining several neuropeptides and traditional neurotransmitter systems to construct neural networks, this hormone modifies signals connected to depression. The present review focuses on the role of ghrelin in neuritogenesis, astrocyte protection, inflammatory factor production, and endocrine disruption in depression. Furthermore, ghrelin/GHSR can activate multiple signaling pathways, including cAMP/CREB/BDNF, PI3K/Akt, Jak2/STAT3, and p38-MAPK, to produce antidepressant effects, given which it is expected to become a potential therapeutic target for the treatment of depression.

The association between depressive symptoms and high-sensitivity C-reactive protein: Is body mass index a moderator?

Objective

Depression and obesity are highly comorbid conditions with shared biological mechanisms. It remains unclear how depressive symptoms and body mass index (BMI) interact in relation to inflammation. This cross-sectional study investigated the independent associations of depressive symptoms and BMI with high sensitivity C-reactive protein (hs-CRP), as well as the moderating role of BMI on the depressive symptoms-hs-CRP association.

Methods

Participants (n = 8827) from the 2015-2018 National Health and Nutrition Examination Surveys were aged ≥20 with a BMI ≥18.5 kg/m2, completed the Depression Screener, and had hs-CRP data. Multivariable linear regression was used to analyze hs-CRP in relation to depressive symptoms and BMI. An interaction term was included to examine whether the depressive symptoms-hs-CRP relationship differs depending on BMI.

Results

There was a slight, albeit non-significant, increase in hs-CRP levels with each one-point increase in depressive symptoms (aCoef.Estm. = 0.01, 95% CI = -0.05, 0.06, p = 0.754). Participants with overweight (aCoef.Estm. = 1.07, 95% CI = 0.61, 1.53, p < 0.001) or obese (aCoef.Estm. = 3.51, 95% CI = 3.04, 3.98, p < 0.001) BMIs had higher mean hs-CRP levels than those with a healthy BMI. There were no significant interactions between depressive symptoms and overweight (aCoef.Estm. = 0.04, 95% CI = -0.04, 0.13, p = 0.278) or obese (aCoef.Estm. = 0.11, 95% CI = -0.01, 0.22, p = 0.066) BMI indicating a lack of difference in the depressive symptoms-hs-CRP association across participants in the healthy versus overweight and obese ranges.

Conclusions

This study suggests that BMI might not act as a moderator in the association between depressive symptoms and hs-CRP. Results should be replicated in larger samples. Further research is warranted to understand underlying mechanisms.

Retinal microvascular abnormalities in major depression

BACKGROUND

The aim of our study was to find a possible association between retinal microvascular abnormality and major depression in a non-geriatric population.

METHOD

The participants with major depression were hospitalised at the University Hospital in Hradec Kralove, Department of Psychiatry. Retinal images were obtained using a stationary Fundus camera FF450 by Zeiss and a hand-held camera by oDocs.

RESULTS

Fifty patients (men n=18, women n=32) aged 16 to 55 (men's average age 33.7±9.9 years, women's average age 37.9±11.5 years) were compared with fifty mentally healthy subjects (men n=28, women n=22) aged 18 to 61 (men's average age 35.3±9.2 years, women's average age 36.6±10.6 years) in a cross-sectional design. The patients were diagnosed with a single depressive episode (n=26) or a recurrent depressive disorder (n=24) according to the ICD-10 classification. Our results confirmed significant microvascular changes in the retina in patients with depressive disorder in comparison to the control group of mentally healthy subjects, with significantly larger arteriolar (P<0.0001) as well as venular (P<0.001-0.0001) calibres in major depression.

CONCLUSION

According to the literature, acute and chronic neuroinflammation is associated with changes in microvascular form and function. The endothelium becomes a major participant in the inflammatory response damaging the surrounding tissue and its function. Because the retina and brain tissue share a common embryonic origin, we suspect similar microvascular pathology in the retina and in the brain in major depression. Our results may contribute to a better understanding of depression etiopathogenesis and to its personalized treatment.

Neuroimmune modulation by tryptophan derivatives in neurological and inflammatory disorders

The nervous and immune systems are highly developed, and each performs specialized physiological functions. However, they work together, and their dysfunction is associated with various diseases. Specialized molecules, such as neurotransmitters, cytokines, and more general metabolites, are essential for the appropriate regulation of both systems. Tryptophan, an essential amino acid, is converted into functional molecules such as serotonin and kynurenine, both of which play important roles in the nervous and immune systems. The role of kynurenine metabolites in neurodegenerative and psychiatric diseases has recently received particular attention. Recently, we found that hyperactivity of the kynurenine pathway is a critical risk factor for septic shock. In this review, we first outline neuroimmune interactions and tryptophan derivatives and then summarized the changes in tryptophan metabolism in neurological disorders. Finally, we discuss the potential of tryptophan derivatives as therapeutic targets for neuroimmune disorders.

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

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

Mediating effect of inflammation on the relationship between sleep disruption and suicidal ideation in major depressive disorder

BACKGROUND

Sleep disruption, particularly insomnia, is a notable characteristic of depression and is associated with an increased risk of suicide in patients diagnosed with major depressive disorder (MDD). Moreover, the pathophysiology of depression and suicide has been linked to inflammation, specifically proinflammatory cytokines. However, the complex interplay among these factors in individuals with MDD remains poorly understood. This study investigated the mediating role of inflammatory cytokines in the relationship between sleep disruption and suicidal ideation (SI), with a particular emphasis on gender differences.

METHODS

This study used a cross-sectional design in which 281 individuals diagnosed with MDD were recruited from psychiatric clinics. The main assessments included the evaluation of sleep disruption, inflammatory markers, and SI. The Beck Scale for Suicide Ideation (SSI) scores was employed to quantify SI, whereas HAMD-SLD, a component of the Hamilton Rating Scale (HAMD-17), was used to evaluate sleep disruption. Blood analysis was performed to measure inflammatory markers.

RESULT

For females diagnosed with MDD, significant associations between sleep disruption and the levels of IL-6 (B = 0.994, p = 0.013) and TNF-α (B = 1.986, p = 0.016) were found when IL-6 or TNF-α were considered as mediators in the regression model. In addition, IL-6 (B = 5.689, p < 0.001) and TNF-α (B = 9.916, p = 0.006) exhibited strong correlation with SSI scores.

CONCLUSIONS

The primary results of this study indicate that IL-6 and TNF-α could function as potential mediators in the relationship between sleep disruption and SI among female patients diagnosed with MDD.

CLINICAL TRIAL

Name of the registry: Zhejiang University Trial registration number: ChiCTR1800017626 Date of registration: 2018-08-07, 'Retrospectively registered' URL of trial registry record: https://www.chictr.org.cn/showproj.html?proj=27321.

Immunotherapy for depression: Recent insights and future targets

Depression stands as a prominent contributor to global disability, entailing an elevated risk of suicide. Substantial evidence supports the notion that immune dysregulation may play a role in the development of depression and impede responses to antidepressant treatments. Immune dysregulation may cause depression in susceptible individuals through raising inflammatory responses. Differences in immune cell types and the release of pro-inflammatory mediators are observed in the blood and cerebrospinal fluid of patients with major depressive disorder, which is associated with neuroimmune dysfunction. Therefore, the interaction of peripheral and central immune targets in depression needs to be understood. Urgent attention is required for the development of innovative therapeutics directed at modulating immune responses for the treatment of depression. This review delineates the immune mechanisms involved in the pathogenesis of depression, assesses the therapeutic potential of immune system targeting for depression treatment, and deliberates on the merits and constraints of employing immunotherapy in the management of depression.

The Pathophysiological Underpinnings of Gamma-Band Alterations in Psychiatric Disorders

Investigating the biophysiological substrates of psychiatric illnesses is of great interest to our understanding of disorders' etiology, the identification of reliable biomarkers, and potential new therapeutic avenues. Schizophrenia represents a consolidated model of γ alterations arising from the aberrant activity of parvalbumin-positive GABAergic interneurons, whose dysfunction is associated with perineuronal net impairment and neuroinflammation. This model of pathogenesis is supported by molecular, cellular, and functional evidence. Proof for alterations of γ oscillations and their underlying mechanisms has also been reported in bipolar disorder and represents an emerging topic for major depressive disorder. Although evidence from animal models needs to be further elucidated in humans, the pathophysiology of γ-band alteration represents a common denominator for different neuropsychiatric disorders. The purpose of this narrative review is to outline a framework of converging results in psychiatric conditions characterized by γ abnormality, from neurochemical dysfunction to alterations in brain rhythms.

Synergistic effects of citicoline and silymarin nanomicelles in restraint stress-exposed mice

This study evaluated the effects of citicoline and silymarin nanomicelles (SMnm) in repeated restraint stress (RRS).

METHOD

Mice were exposed to RRS for four consecutive days, 2 hrs. daily. On day 5 of the study, SMnm (25 and 50 mg/kg, i.p.) and citicoline (25 and 75 mg/kg), and a combination of them (25 mg/kg, i.p.) were initiated. On day 18, anxiety-like behavior, behavioral despair, and exploratory behavior were evaluated. The prefrontal cortex (PFC) and the hippocampus were dissected measuring brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), and tumor necrosis factor-alpha (TNF-α) through Western Blot and ELISA, respectively.

RESULTS

In RR-exposed mice, anxiety-like behavior in the elevated plus maze (EPM) was enhanced by reductions in open arm time (OAT%) P < 0.001, and open arm entry (OAE%) P < 0.001. In the forced swimming test (FST), the immobility increased P < 0.001 while the swimming and climbing reduced P < 0.001. In the open field test (OFT), general motor activity was raised P < 0.05. Further, body weights reduced P < 0.001, and tissue BDNF and pCREB expressions decreased P < 0.001 while TNF-α increased P < 0.001. Conversely, SMnm, citicoline and their combination could reduce anxiety-like behavior P < 0.001. The combination group reduced the depressive-like behaviors P < 0.001. Moreover, body weights were restored P < 0.001. Besides, BDNF and pCREB expressions increased while TNF-α reduced, P < 0.001.

CONCLUSION

The combination synergistically improved emotion-like behaviors, alleviating the inflammation and upregulating the hippocampal BDNF-mediated CREB signaling pathway.

Paediatric Atopic Dermatitis: The Unexpected Impact on Life with a Specific Look at the Molecular Level

Atopic dermatitis (AD) is a condition with a multifactorial aetiology that affects the skin. It most often begins at preschool age and involves the skin. The disease's main symptom is intense itching, which occurs especially at night and affects the child's sleep, negatively impacting the quality of life of affected children and, consequently, their families. The difficulty in resting during the night leads to many problems during the day, particularly behavioural disorders and difficulties in paying attention at school, which results in learning impairment. The unexpected symptoms of AD are caused by pathophysiological processes that include many molecular pathways and inflammatory cytokines such as IL-31, IL-1, IL-2, TNF-a, and IL-6. Drawing on a comprehensive review of the literature in PubMed/MedLine, our review offers an in-depth exploration of both the psychosocial impacts of AD and the molecular processes that contribute to this disorder.

Evaluation of anti-inflammatory activity of kaurenol: Experimental evaluation and mechanistic insights

BACKGROUND

Kaurenol, a diterpene alcohol found in Copaifera langsdorffii Desf. (known as "copaiba"), is historically used in traditional medicine for inflammatory conditions.

OBJECTIVES

This study aims to comprehensively assess the potential anti-inflammatory and antinociceptive properties of kaurenol.

METHODS

To this end, the following experiments were conducted to evaluated toxicity: locomotor performance and acute toxicity; nociception: acetic acid-induced writhing and formalin-induced antinociception; and anti-inflammatory activity: carrageenan and dextran-induced paw edema at 10, 20, and 40 mg/kg, and measurement of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in macrophages at 1, 3, and 9 μg/ml.

RESULTS

Kaurenol did not show significant locomotor changes, acute toxicity, and central analgesic activity in the first phase of formalin test at dosages tested. Kaurenol showed 53%, 64%, 64%, and 58% of inhibition in the acetic acid-induced writhing, second phase of formalin test, carrageenan and dextran-induced paw edema, respectively.

CONCLUSION

The anti-inflammatory activity was associated with the regulation of NO release and probably with the regulation of mediators, such as serotonin and prostaglandin in vascular permeability, as well as by being associated with the regulation of IL-6 and IL-10. Kaurenol display anti-inflammatory activity but has no analgesic activity.

Chronic stress alters lipid mediator profiles associated with immune-related gene expressions and cell compositions in mouse bone marrow and spleen

Despite the importance of lipid mediators in stress and depression and their link to inflammation, the influence of stress on these mediators and their role in inflammation is not fully understood. This study used RNA-seq, LC-MS/MS, and flow cytometry analyses in a mouse model subjected to chronic social defeat stress to explore the effects of acute and chronic stress on lipid mediators, gene expression, and cell population in the bone marrow and spleen. In the bone marrow, chronic stress induced a sustained transition from lymphoid to myeloid cells, accompanied by corresponding changes in gene expression. This change was associated with decreased levels of 15-deoxy-d12,14-prostaglandin J2, a lipid mediator that inhibits inflammation. In the spleen, chronic stress also induced a lymphoid-to-myeloid transition, albeit transiently, alongside gene expression changes indicative of extramedullary hematopoiesis. These changes were linked to lower levels of 12-HEPE and resolvins, both critical for inhibiting and resolving inflammation. Our findings highlight the significant role of anti-inflammatory and pro-resolving lipid mediators in the immune responses induced by chronic stress in the bone marrow and spleen. This study paves the way for understanding how these lipid mediators contribute to the immune mechanisms of stress and depression.

CRISPR/Cas9 based gene editing of Frizzled class receptor 6 (FZD6) reveals its role in depressive symptoms through disrupting Wnt/β-catenin signaling pathway

INTRODUCTION

As one of the common psychiatric diseases, depression poses serious threats to human health. Although many genes have been nominated for depression, few of them were investigated in details at the molecular level.

OBJECTIVES

To demonstrate Frizzled class receptor 6 (FZD6) functions in depression through disrupting Wnt/β-catenin signal pathway.

METHODS

The FZD6 edited cell line and mouse model were generated by using CRISPR/Cas9 technique. The expression of key genes and proteins in Wnt/β-catenin pathway was determined by qRT-PCR and Western blotting, respectively. Animal behavioral tests, including open field test (OFT), elevated plus maze test (EPM), forced swimming test (FST), tail suspension test (TST), and sucrose preference test (SPT), were employed to determine anxiety- and depressive-like behaviors. Immunofluorescent staining was used to assess cell proliferation in the hippocampus of mouse brain.

RESULTS

Among patients with depression, FZD6, one of the receptors of Wnt ligand, was significantly decreased. In CRISPR/Cas9-based FZD6 knockdown cells, we showed that FZD6 plays a significant role in regulating expression of genes involved in Wnt/β-catenin pathway. Subsequently behavioral studies on Fzd6 knockdown mice (with a 5-nucleotide deletion; Fzd6-Δ5) revealed significant changes in depressive symptoms, including increased immobility duration in FST, less preference of sucrose in SPT, reduction of distance traveled in OFT, and decreased time spent in open arms in EPM. Immunofluorescent staining showed decreased cell proliferation in the hippocampus of Fzd6-Δ5 mice with reduced number of Ki67+ and PCNA+ cells. Moreover, decreased Gsk3β mRNA expression, phosphorylated GSK3β, and cytoplasmic β-catenin in the hippocampus of Fzd6-Δ5 mice provided further evidence supporting the role of Fzd6 in depression.

CONCLUSION

Together, above findings proved the significant role of FZD6 in depression through its effect on hippocampal cell proliferation and its ability to regulate canonical Wnt/β-catenin pathway.

Maternal prenatal lead levels and neonatal brain volumes: Testing moderations by maternal depressive symptoms and family income

There is considerable evidence that prenatal lead exposure is detrimental to child cognitive and socio-emotional development. Further evidence suggests that the effects of prenatal lead on developmental outcomes may be conditional upon exposure to social stressors, such as maternal depression and low socioeconomic status. However, no studies have examined associations between these co-occurring stressors during pregnancy and neonatal brain volumes. Leveraging a sample of 101 mother-infant dyads followed beginning in mid-pregnancy, we examined the main effects of prenatal urinary lead levels on neonatal lateralized brain volumes (left and right hippocampus, amygdala, cerebellum, frontal lobes) and total gray matter. We additionally tested for moderations between lead and depressive symptoms and between lead and family income relative to the federal poverty level (FPL) on the same neurodevelopmental outcomes. Analyses of main effects indicated that prenatal lead was significantly (ps < 0.05) associated with reduced right and left amygdala volumes (βs = -0.23- -0.20). The testing and probing of cross-product interaction terms using simple slopes indicated that the negative effect of lead on the left amygdala was conditional upon mothers having low depressive symptoms or high income relative to the FPL. We interpret the results in the context of trajectories of prenatal and postnatal brain development and susceptibility to low levels of prenatal lead in the context of other social stressors.

N-acetylcysteine ameliorates chemotherapy-induced impaired anxiety and depression-like behaviors by regulating inflammation, oxidative and cholinergic status, and BDNF release

Mood disorders caused by chemotherapy have become more important as the survival of cancer patients increases, and new studies in this field will contribute to the prevention of this disorder. For this purpose, we used methotrexate, a chemotherapeutic agent frequently preferred in oncological cases. Mtx was administered as a single dose of 100 mg/kg intraperitoneally to male Wistar albino rats. Since oxidative stress plays an important role in chemotherapy-induced emotional impairment, n-acetylcysteine (NAC), a potent antioxidant, was administered at 500 mg/kg in two doses before Mtx administration. We evaluated anxiety and depression-like behaviors 24 h after Mtx administration, as well as some oxidative and inflammatory markers in blood serum and hippocampal tissue, acetylcholinesterase activity (AChE), and brain-derived neurotrophic factor (BDNF) release in hippocampal tissue. In rats, Mtx induced anxiety and depression-like behaviors as well as abnormalities in oxidative and inflammatory markers in blood serum and hippocampal tissue, increased AChE activity in hippocampal tissue, and decreased BDNF release. NAC treatment was found to ameliorate Mtx-induced anxiety and depression-like behaviors, increase antioxidant capacity, reduce oxidative stress and inflammatory response, and regulate AChE activity and BDNF release. In conclusion, the fact that NAC treatment of Mtx was effective is important for revising the treatment strategies for individuals suffering from this disorder, and this effect is thought to be related to the antioxidant and anti-inflammatory power of NAC.

Gender difference on the mediation effects of filial piety on the association between chronic obstructive pulmonary disease and depressive symptoms in older adults: A community-based study

Filial piety is viewed as strong family support for older Chinese people, and strongly associated with depressive symptoms. It is unknown if there exists gender difference in the mediation effects of filial piety on the relationship between chronic obstructive pulmonary disease (manifested as lung function) and depression. We investigated whether filial piety mediates the association between lung function and depression in community-dwelling older men and women using the Healthy Aging Longitudinal Study in Taiwan (HALST). Community dwelling adults aged 65 and above were analyzed. Pulmonary function, depressive symptoms, and filial piety expectation (FPE) and receipt of filial piety (RFP) were collected. The interaction and mediation of filial piety between lung function and depression was analyzed. We found that in older men, forced expiratory volume in the first second (FEV1) was inversely correlated with depression (β = -0.1281, p = 0.004) with no mediation effect of FPE. In older women, FEV1 was negatively associated with FPE, but FPE did not increase the risk of depression (β = 0.0605, p = 0.12). In both older men and women, FEV1 was negatively associated with RFP, while RFP reduced the risk of depression (p< 0.001). In older women, the correlation between FEV1 was complete mediation of RFP. Results indicate that feelings of insufficient filial piety may increase the likelihood of depression, especially in elderly women with worse lung function. Although modest, the main mediation effect of filial piety was improvement of lung function in older subjects, which might decrease depression.

Untargeted Plasma Metabolomic Profiling in Patients with Depressive Disorders: A Preliminary Study

Depressive disorder is a multifactorial disease that is based on dysfunctions in mental and biological processes. The search for biomarkers can improve its diagnosis, personalize therapy, and lead to a deep understanding of the biochemical processes underlying depression. The purpose of this work was a metabolomic analysis of blood serum to classify patients with depressive disorders and healthy individuals using Compound Discoverer software. Using high-resolution mass spectrometry, blood plasma samples from 60 people were analyzed, of which 30 were included in a comparison group (healthy donors), and 30 were patients with a depressive episode (F32.11) and recurrent depressive disorder (F33.11). Differences between patient and control groups were identified using the built-in utilities in Compound Discoverer software. Compounds were identified by their accurate mass and fragment patterns using the mzCloud database and tentatively identified by their exact mass using the ChemSpider search engine and the KEGG, ChEBI, FDA UNII-NLM, Human Metabolome and LipidMAPS databases. We identified 18 metabolites that could divide patients with depressive disorders from healthy donors. Of these, only two compounds were tentatively identified using the mzCloud database (betaine and piperine) based on their fragmentation spectra. For three compounds ((4S,5S,8S,10R)-4,5,8-trihydroxy-10-methyl-3,4,5,8,9,10-hexahydro-2H-oxecin-2-one, (2E,4E)-N-(2-hydroxy-2-methylpropyl)-2,4-tetradecadienamide and 17α-methyl-androstan-3-hydroxyimine-17β-ol), matches were found in the mzCloud database but with low score, which could not serve as reliable evidence of their structure. Another 13 compounds were identified by their exact mass in the ChemSpider database, 9 (g-butyrobetaine, 6-diazonio-5-oxo-L-norleucine, 11-aminoundecanoic acid, methyl N-acetyl-2-diazonionorleucinate, glycyl-glycyl-argininal, dilaurylmethylamine, 12-ketodeoxycholic acid, dicetylamine, 1-linoleoyl-2-hydroxy-sn-glycero-3-PC) had only molecular formulas proposed, and 4 were unidentified. Thus, the use of Compound Discoverer software alone was not sufficient to identify all revealed metabolites. Nevertheless, the combination of the found metabolites made it possible to divide patients with depressive disorders from healthy donors.

A cross talk on the role of contemporary biomarkers in depression

Introduction: Biomarkers can be used to identify determinants of response to various treatments of mental disorders. Evidence to date demonstrates that markers of inflammatory, neurotransmitter, neurotrophic, neuroendocrine, and metabolic function can predict the psychological and physical consequences of depression in individuals, allowing for the development of new therapeutic targets with fewer side effects. Extensive research has included hundreds of potential biomarkers of depression, but their roles in depression, abnormal patients, and how bioinformatics can be used to improve diagnosis, treatment, and prognosis have not been determined or defined. To determine which biomarkers can and cannot be used to predict treatment response, classify patients for specific treatments, and develop targets for new interventions, proprietary strategies, and current research projects need to be tailored.Material and Methods: This review article focuses on - biomarker systems that would help in the further development and expansion of newer targets - which holds great promise for reducing the burden of depression.Results and Discussion: Further, this review point to the inflammatory response, metabolic marker, and microribonucleic acids, long non-coding RNAs, HPA axis which are - related to depression and can serve as future targets.

Investigation of peripheral inflammatory biomarkers in association with suicide risk in major depressive disorder

Suicide is the most severe complication of major depressive disorder (MDD). Novel research assumes the role of immunological dysregulation in the background - several studies have reported alterations in the number of inflammatory cells related to both MDD and suicidality. There are currently no objective, routinely measured parameters to indicate suicidal vulnerability. However, altered inflammatory cell numbers and ratios have been proposed as potential biomarkers of suicide risk (SR). The present research aims to examine changes of these values related to increased SR in MDD as an assumed inflammatory state. We investigated laboratory parameters of psychiatric in-patients diagnosed with MDD (n = 101) retrospectively. Individuals with recent suicide attempt (SA) (n = 22) and with past SA (n = 19) represented the high SR group. MDD patients with no history of SA (n = 60) composed the intermediate SR group. We compared the number of neutrophil granulocytes, monocytes, lymphocytes, platelets, white blood cell count (WBC), neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), red blood cell distribution width (RDW) and erythrocyte sedimentation rate (ESR). Furthermore, we evaluated alterations of these parameters related to antidepressant (AD) and antipsychotic (AP) treatment, which have been proved to have anti-inflammatory effects. We found a significant increase in neutrophil granulocyte count, NLR, monocyte count, MLR, WBC and ESR in patients with recent SA compared to patients with no history of SA. Moreover, there was a significant elevation in monocyte count, MLR, ESR and RDW in patients with high SR compared to patients with intermediate SR. AD treatment resulted in a significant decrease in neutrophil granulocyte count and NLR, however, it did not affect monocyte count and MLR. Assuming immunological mechanisms in the background of MDD and suicidality, our findings support the role of NLR as a biomarker of acute SR, though its alterations may be masked by possible anti-inflammatory effects of AD treatment in the long term. However, MLR, a marker exhibiting changes which are not attenuated by pharmacotherapy, may be a possible indicator of both acute and long-term suicidal vulnerability.

Role of metabolic risk factors in the relationship between ambient fine particulate matter and depressive symptoms: Evidence from a longitudinal population study

BACKGROUND

There is growing evidence indicating a connection between fine particulate matter (PM2.5) and depressive symptoms. Metabolic risk factors are critical determinants of depressive symptoms. However, the mediating role of these factors on the association between PM2.5 and depressive symptoms remains elusive. We aimed to investigate whether and to what extent metabolic risk factors mediated the link between long-term PM2.5 exposure and depressive symptoms.

METHODS

This study comprised 7794 individuals aged between 30 and 79 years who participated in two waves of the on-site surveys in the China Multi-Ethnic Cohort. Ambient PM2.5 concentrations were assessed utilizing a random forest method based on satellite data. We employed the Patient Health Questionnaire-9 to assess depressive symptoms at wave 2, and the overall as well as three sub-domain symptom scores (emotional, neurovegetative, and neurocognitive symptoms) were calculated. Three metabolic risk factors, including hypertension, diabetes, and dyslipidemia, were considered. Mediation analyses were conducted to assess the indirect effects of PM2.5 on depressive symptoms through metabolic risk factors.

RESULTS

We found a positive association between chronic exposure to ambient PM2.5 and overall depressive symptoms as well as the three sub-domains. In mediation analyses, metabolic risk factors partially mediated the associations of PM2.5 on depressive symptoms. The natural indirect effects (RR, 95% CI) of PM2.5 on overall, emotional, neurovegetative, and neurocognitive symptoms mediated through metabolic risk factors were 1.004(1.001, 1.007), 1.004 (1.001, 1.008), 1.004 (1.001, 1.007), and 1.003(0.999, 1.007), respectively. Larger indirect effects were found in elderly participants (mediated proportion, 29.3%), females (13.3%), and people who did not consume alcohol (19.6%).

CONCLUSIONS

Metabolic risk factors may act as mediators in the relationship between chronic PM2.5 exposure and depression. Treatment of metabolic risk factors may be an opportunity to reduce the burden of depression caused by long-term exposure to PM2.5.

Clinical characterization, physical frailty, and depression in elderly patients with psoriasis from a reference center in Brazil: a cross-sectional study

BACKGROUND

There are few studies dedicated to the characterization of the geriatric population with psoriasis, which has particularities in terms of clinical manifestations and therapeutic limitations. As psoriasis is a chronic disease, presenting a higher prevalence with age, the increase in life expectancy in Brazil demands knowledge about the behavior of the disease among the elderly.

OBJECTIVES

To characterize elderly people with psoriasis from a tertiary service, from the clinical-epidemiological point of view, presence of comorbidities, physical frailty, and affective impact, and to compare these aspects with adults with psoriasis and elderly people without the disease.

METHODS

Cross-sectional study of 64 elderly patients with psoriasis, 64 adults with psoriasis, and 64 elderly patients without the disease. Clinical-demographic aspects, the Beck depression scale, and Skindex-16 were evaluated. Indicators of physical frailty were evaluated in elderly patients: handgrip, sit-to-stand test, fatigue, and weight loss >5%.

RESULTS

In the elderly, the mean age (SD) of psoriasis onset was 44 (10) years, men represented 47% of the sample, the prevalence of arthritis was 22%, and ungual involvement occurred in 72%. Topical corticosteroids were used more often among elderly people with psoriasis (100%) than among adults with the disease (86%), with no difference among other systemic treatments. Diabetes mellitus occurred in 30% of the elderly. Hypertension (59%), dyslipidemia (52%), depression (34%), and fatigue (59%) were more prevalent among the elderly with psoriasis than among the healthy controls.

STUDY LIMITATIONS

The study was carried out in a public reference service for patients with psoriasis, all of which were undergoing treatment.

CONCLUSIONS

Elderly people with psoriasis from a tertiary service showed greater affective impairment, metabolic comorbidities, and physical frailty than elderly controls.

The Gut Microbiota and Major Depressive Disorder: Current Understanding and Novel Therapeutic Strategies

Major depressive disorder (MDD) is a common neuropsychiatric challenge that primarily targets young females. MDD as a global disorder has a multifactorial etiology related to the environment and genetic background. A balanced gut microbiota is one of the most important environmental factors involved in human physiological health. The interaction of gut microbiota components and metabolic products with the hypothalamic-pituitary-adrenal system and immune mediators can reverse depression phenotypes in vulnerable individuals. Therefore, abnormalities in the quantitative and qualitative structure of the gut microbiota may lead to the progression of MDD. In this review, we have presented an overview of the bidirectional relationship between gut microbiota and MDD, and the effect of pre-treatments and microbiomebased approaches, such as probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and a new generation of microbial alternatives, on the improvement of unstable clinical conditions caused by MDD.

Downregulated NPAS4 in multiple brain regions is associated with major depressive disorder

Major Depressive Disorder (MDD) is a commonly observed psychiatric disorder that affects more than 2% of the world population with a rising trend. However, disease-associated pathways and biomarkers are yet to be fully comprehended. In this study, we analyzed previously generated RNA-seq data across seven different brain regions from three distinct studies to identify differentially and co-expressed genes for patients with MDD. Differential gene expression (DGE) analysis revealed that NPAS4 is the only gene downregulated in three different brain regions. Furthermore, co-expressing gene modules responsible for glutamatergic signaling are negatively enriched in these regions. We used the results of both DGE and co-expression analyses to construct a novel MDD-associated pathway. In our model, we propose that disruption in glutamatergic signaling-related pathways might be associated with the downregulation of NPAS4 and many other immediate-early genes (IEGs) that control synaptic plasticity. In addition to DGE analysis, we identified the relative importance of KEGG pathways in discriminating MDD phenotype using a machine learning-based approach. We anticipate that our study will open doors to developing better therapeutic approaches targeting glutamatergic receptors in the treatment of MDD.

Anxiolytic and antidepressant like effects of Zamzam water in STZ-induced diabetic rats, targeting oxidative stress, neuroinflammation, BDNF/ERK/CREP pathway with modulation of hypothalamo-pituitary-adrenal axis

Introduction

Recent studies have reported a strong relationship between diabetes and anxiety- and depression-like behaviors; however, there is a lack of information on the underlying pathophysiology. Alkaline Zamzam water (ZW), which is rich in several trace elements, has neuroprotective properties. This study aimed to investigate the anxiolytic and antidepressant effects of ZW against diabetes-induced behavioral changes and shed light on the possible underlying mechanisms.

Methods

Forty-eight rats were divided into four experimental groups (n = 12): group I (control group), group II (Zamzam water group), group III (diabetic group), and group IV (diabetic + Zamzam water group). Diabetes was induced by an intraperitoneal injection of 60 mg/kg streptozotocin (STZ). At the end of the experiment, the forced swimming test (FST) was used to assess depression-like effects. The elevated plus maze test (EPMT) and open field test (OFT) were performed to evaluate anxiety-like behavior. Blood levels of the hypothalamic-pituitary-adrenal (HPA) axis were measured, and prefrontal cortex and hippocampal tissue samples were removed for histological, immunohistochemical, ELISA, and Q-PCR analyses.

Results

ZW significantly decreased the immobility time in the FST, indicating an antidepressant effect (p < 0.001). Additionally, ZW significantly improved the OFT and open field entry (OFE) percentages in the EPMT, increasing center crossing and decreasing grooming and fecal boli in the OFT. This indicated an anxiolytic-like effect in diabetic rats with histological improvement. Interestingly, ZW significantly increased prefrontal cortical and hippocampal levels of antioxidant enzymes and the Nrf2/HO-1 pathway. It also modulated the HPA axis by increasing cortisol and corticotropin-releasing hormone (CRH) levels, with a decrease in ACTH and an increase in monoamine neurotransmitters. Furthermore, diabetic rats that received ZW showed a decrease in the inflammatory markers TNF-α and GFAP by immunohistochemistry and in the mRNA levels of NFκB, IL-1β, and IL6. In addition, ZW downregulated the expression of the BDNF/ERK2/CREP pathway.

Conclusion

Our results suggested a neuroprotective effect of ZW against diabetes-induced anxiety- and depression-like behaviors and explored the underlying mechanisms. These findings suggest a promising therapeutic strategy for patients with diabetes who experience anxiety and depression.

Itaconate: A promising precursor for treatment of neuroinflammation associated depression

Neuroinflammation triggers the production of inflammatory factors, influences neuron generation and synaptic plasticity, thus playing an important role in the pathogenesis of depression and becoming an important direction of depression prevention and treatment. Itaconate is a metabolite secreted by macrophages in immunomodulatory responses, that has potent immunomodulatory effects and has been proven to exert anti-inflammatory effects in a variety of diseases. Microglia are mononuclear macrophages that reside in the central nervous system (CNS), and may be the source of endogenous itaconate in the brain. Itaconate can directly inhibit succinate dehydrogenase (SDH), reduce the production of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), activate nuclear factor erythroid-2 related factor 2 (Nrf2), and block glycolysis, and thereby improving the depressive symptoms associated with the above mechanisms. Notably, itaconate also indirectly ameliorates the depressive symptoms associated with some inflammatory diseases. With the optimization of the structure and the development of new delivery systems, the application value and therapeutic potential of itaconate have been significantly improved. Dimethyl itaconate (DI) and 4-octyl itaconate (4-OI), cell-permeable derivatives of itaconate, are more suitable for crossing the blood-brain barrier (BBB), exhibiting therapeutic effects in the research of multiple diseases. This article provides an overview of the immunomodulatory effects of itaconate and its potential therapeutic efficacy in inflammatory depression, focusing on the promising application of itaconate as a precursor of antidepressants.

Altered cortical myelin in the salience and default mode networks in major depressive disorder patients: A surface-based analysis

INTRODUCTION

Evidence from previous genetic and post-mortem studies suggested that the myelination abnormality contributed to the pathogenesis of major depressive disorder (MDD). However, image-level alterations in cortical myelin content associated with MDD are still unclear.

METHODS

The high-resolution T1-weighted (T1w) and T2-weighted (T2w) brain 3D structural images were obtained from 52 MDD patients and 52 healthy controls (HC). We calculated the vertex-based T1w/T2w ratio using the HCP structural pipelines to characterize individual cortical myelin maps at the fs_LR 32 k surface. We attempted to detect the clusters with significant differences in cortical myelin content between MDD and HC groups. We correlated the cluster-wise averaged myelin value and the clinical performances in MDD patients.

RESULTS

The MDD patients showed significantly lower cortical myelin content in the cluster involving the left insula, orbitofrontal cortex, superior temporal cortex, transverse temporal gyrus, inferior frontal cortex, superior frontal gyrus, anterior cingulate cortex, precentral cortex, and postcentral cortex. The correlation analysis showed a significantly positive correlation between the cluster-wise cortical myelin content and the onset age of MDD patients.

CONCLUSION

The MDD patients showed lower cortical myelin content in regions of the default mode network regions and salience network than healthy controls.

Fluoxetine combined with swimming exercise synergistically reduces lipopolysaccharide-induced depressive-like behavior by normalizing the HPA axis and brain inflammation in mice

Major depression disorder is a debilitating psychiatric disease affecting millions of people worldwide. This disorder is the leading cause of morbidity and mortality in high-income countries. Selective serotonin reuptake inhibitors such as fluoxetine are first-line drugs for treating depression-related disorders, but not all patients respond well to these antidepressants. This study aimed to evaluate whether fluoxetine combined with aerobic exercise can affect lipopolysaccharide (LPS)-induced depressive-like behavior, hypothalamic-pituitary-adrenal (HPA) axis dysregulation, and brain inflammation in mice. Male mice were exposed to fluoxetine, swimming exercise, or a combination of both and finally treated with LPS. We measured depression-related symptoms such as anhedonia, behavioral despair, weight gain, and food intake. Hormones (corticosterone and testosterone) and cytokines (IL-1β, IL-6, TNF-α, IL-10) were also measured in serum and brain (hippocampus and prefrontal cortex), respectively. The findings indicated that LPS induced anhedonia and behavioral despair and increased corticosterone, hippocampal IL-1β, TNF-α, and decreased testosterone and hippocampal IL-10 in mice. Fluoxetine and exercise separately reduced LPS-induced depressive-like behavior, while their combination synergistically reduced these symptoms in LPS-treated mice. We found fluoxetine alone increased food intake and body weight in LPS-treated mice. Fluoxetine and exercise combination reduced corticosterone, hippocampal TNF-α, and prefrontal IL-6 and TNF-α levels and increased testosterone and hippocampal and prefrontal IL-10 levels more effectively than fluoxetine alone in LPS-treated mice. This study suggests that swimming exercise combined with fluoxetine can affect depression-related behavior, HPA axis, and brain inflammation more effectively than when they are used separately.

Correlations between omega-3 fatty acids and inflammatory/glial abnormalities: the involvement of the membrane and neurotransmitter dysfunction in schizophrenia

Introduction

Macrophages or T-lymphocytes triggered inflammation and, consequently, activated glial cells may contribute to neuroinflammation and neurotransmitter dysfunction in schizophrenia (SZ), while omega(n)-3 polyunsaturated fatty acids (PUFAs) can attenuate some SZ symptoms through anti-inflammatory effects. However, the correlations between macrophage/T-lymphocyte-produced cytokines and glia phenotypes, between inflammatory status and PUFAs composition, between cytokines and neurotransmitter function, and between n-3 PUFAs and neurotransmitter abnormality in SZ are unclear.

Methods

Changes in T-helper (h) patterns, peripheral macrophage/glial markers, PUFAs profile, membrane fluidity, and neurotransmitter functions were evaluated in SZ patients (n = 50) and healthy controls (n = 30) using ELISA, gas chromatography, fluorescence anisotropy techniques, and HPLC, respectively.

Results

Compared to the control, blood lymphocyte proliferation, the concentration of macrophage/microglia phenotype M1 markers, including cytokines IL-1β, TNF-α (Th1) and IL-6 (Th2), and astrocyte phenotype A1 marker S100β was significantly increased, while IL-17 and n-3 PUFAs contents, n-3/n-6 ratio, and membrane fluidity (FLU) were significantly decreased in SZ. Moreover, increased DA and HVA, decreased 5-HT and NE, and their metabolites appeared in SZ. Moreover, negative correlations between IL-6 and A2 marker Brain-Derived Neurotrophic Factor (BDNF) or n-3 PUFAs EPA and between IL-1β and FLU or 5HIAA, while positive correlations between EPA and 5-HIAA and between FLU and DHA were found in SZ.

Discussion

These findings showed (1) no clear Th pattern, but pro-inflammatory-dominant immunity occurred; (2) the pro-inflammatory pattern may result in the activated microglia M1 and astrocyte A1 phenotype; and (3) increased pro-inflammatory cytokines were related to decreased n-3 PUFA and decreased membrane fluidity and dysfunctional neurotransmitter systems in SZ.

Interactions between environmental sensitivity and gut microbiota are associated with biomarkers of stress-related psychiatric symptoms

BACKGROUND

Humans vary in their sensitivity to stressful and supportive environments and experiences. Such individual differences in environmental sensitivity are associated with mechanisms of stress-related psychiatric symptoms. In recent years, researchers have focused on bidirectional interactions in the brain-gut-microbiota axis as a neurophysiological pathway contributing to the mechanisms of stress-related psychiatric symptoms, and evidence is rapidly accumulating.

METHODS

Data on environmental sensitivity, gut microbiota, gut permeability (lipopolysaccharide-binding protein; LBP) and inflammation (C-reactive protein; CRP) were collected from 90 adults (50 % female; Mage = 42.1; SDage = 10.0). Environmental sensitivity was measured using a self-report questionnaire. Study participants' feces were analyzed, and observed operational taxonomic units for richness, Shannon's index for evenness, and phylogenetic diversity for biodiversity were evaluated as indicators of gut microbiota. In addition, participants' serum was analyzed for CRP and LBP. We investigated whether the interaction between environmental sensitivity and gut microbiota is associated with biomarkers of inflammation and gut permeability.

RESULTS

The interaction between environmental sensitivity and gut microbiota (excluding the Shannon's index) explained the levels of these biomarkers. Individuals with high environmental sensitivity displayed higher levels of CRP and LBP, when the richness and diversity of the gut microbiota was low. However, even highly susceptible individuals had lower levels of CRP and LBP, when the richness and diversity of the gut microbiota was high.

CONCLUSIONS

Our study indicates that high environmental sensitivity can be a risk factor for inflammation and gut permeability, when the gut microbiota diversity is low, suggesting a brain-gut-microbiota axis interaction.

Inflammatory markers of symptomatic remission at 6 months in patients with first-episode schizophrenia

Neuroinflammation contributes to the pathophysiology of various mental illnesses including schizophrenia. We investigated peripheral inflammatory cytokines as a biomarker for predicting symptomatic remission in patients with first-episode schizophrenia. The study included 224 patients aged 15-60 years who fulfilled the criteria for schizophrenia spectrum disorder with a treatment duration ≤6 months. Serum levels of tumor necrosis factor (TNF) -α, interferon-γ, interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-10, and IL-12 were measured. Psychotic symptoms, depressive symptoms, and general functioning were assessed using the Positive and Negative Syndrome Scale, Beck Depression Inventory (BDI), Calgary Depression Scale for Schizophrenia, and Personal and Social Performance scale, respectively. Duration of untreated psychosis (DUP) was also recorded. We investigated the factors associated with remission for each sex in logistic regression analysis. In total, 174 patients achieved remission at the 6-month follow-up (females, 83.5%; males, 70.9%). Remission was associated with older age and lower BDI scores in male patients and with lower TNF-α levels and shorter DUP in female patients. Our findings suggest that peripheral inflammatory cytokines may impede early symptomatic remission in female patients with schizophrenia. In addition, depressive symptoms in males and long DUP in females may be poor prognostic factors for early remission in patients with first-episode psychosis.

Effectiveness of aerobic and resistance exercise in cancer survivors with depression: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

AE and RE have been found to be effective for depressive symptoms. However, a systematic review and meta-analysis of studies examining the effectiveness of exercises for cancer survivors with depressive symptoms is lacking. We aimed to synthesize studies assessing AE and RE's efficacy and examine their effects on depressive symptoms among cancer survivors using meta-analyses.

METHODS

This review was registered on the PROSPERO website with ID CRD42023389760. A systematic literature search was conducted in the four databases. Data were synthesized using a random-effect model to analyze the impact of AE and RE on depressive symptoms at posttreatment and in medium-term follow-up relative to the control group. Subgroup analyses were conducted to investigate which factors are relevant to greater or lesser effects of treating depressive symptoms among cancer survivors.

RESULTS

28 RCTs (2942 participants) were identified. Analyses of the between-group showed that AE and/or RE were effective in alleviating depressive symptoms among cancer survivors in immediate posttreatment (SMD = -0.16; 95% CI = -0.29 to -0.03; p = 0.02) but not in medium-term follow-up (SMD = -0.01; 95% CI = -0.57 to 0.55; p = 0.97). Subgroup analyses suggested that AE and exercise 3 times per week were significant moderators.

CONCLUSION

AE and RE were feasible in mitigating depressive symptoms in cancer patients. Further studies are needed to examine if exercise is psychologically beneficial for patients with specific types of cancer.

The role of gut microbiota in the pathogenesis and treatment of postpartum depression

Postpartum depression (PPD) is a common complication of pregnancy in women, and its pathogenesis mainly involves disturbances of the neuroendocrine regulation, immune system, neurotransmitters, hormone secretion, and the gut microbiome. Gut microbes play essential physiological and pathological roles in the gut-brain axis' pathways which are involved in various central nervous system (CNS) and psychiatric disorders, including PPD. Numerous studies have identified the fundamental role of the gut-brain axis in the pathogenesis and treatment of PPD patients and also correlates with other pathogenic mechanisms of PPD. Disturbances in gut microbes are associated with the disruption of multiple signaling pathways and systems that ultimately lead to PPD development. This review aimed to elucidate the potential connections between gut microbes and the established PPD network, and this might serve as a guide for the development of new efficient diagnostic, therapeutic, and prognostic strategies in the management of PPD.

Cutaneous neuropeptides: the missing link between psychological stress and chronic inflammatory skin disease?

A "brain-skin" connection has been long been observed between chronic stress and chronic inflammatory skin disease including urticaria, psoriasis, atopic dermatitis, and prurigo nodularis. The relationship appears to be bidirectional. Chronic psychological stress has been shown to sustain hyperactivity of the sympathetic branch of the autonomic nervous system. Chronic stress is proinflammatory and in the context of several dermatologic disorders may be associated with an increase in dermal nerve fiber density, mast cells, nerve growth factor and calcitonin-gene-related peptide (CGRP). Furthermore, CGRP elicits a TH2-polarized T-cell response that is a hallmark of chronic pruritic conditions such as atopic dermatitis and prurigo nodularis. This TH2 response contributes directly to acute pruritus as well as the sensitization of cutaneous sensory neurons that are critical for chronic pruritus. Prurigo nodularis is a debilitating skin disorder featuring prominent nerve structural, neuropeptide, and TH2 cytokine aberrations that is a model deserving of future study.

Ginsenoside-Rg1 synergized with voluntary running exercise protects against glial activation and dysregulation of neuronal plasticity in depression

Depression is a common psychological disease accompanied by mental disorders and somatic symptoms. However, the underlying mechanisms regarding the pathogenesis of depression are still not clear. Neuronal damage resulting from inflammation is considered to be one of the important risk factors for depression. Ginsenoside-Rg1, a sterol extract extracted from ginseng herbs, has been shown to have neuroprotective effects against neurodegenerative diseases. Moreover, running exercise, a simple behavioral therapy, has been recently shown to have antidepressant effects. However, whether these two synergized strategies are more efficient in depression treatment, especially the neural mechanisms underlying this practical and interesting treatment is unknown. In this study, we have shown that ginsenoside-Rg1 synergized with voluntary running exercise exerts more efficiency on suppressing neuroinflammation, up-regulating expression of neurotrophic factors, and synaptic-related proteins, ameliorating neuronal structural damages than that of ginsenoside-Rg1 or voluntary exercise alone, suggesting its better neuroprotective effects. More importantly, the antidepressant-like effect of this synergistic treatment was also significantly better than either of these two treatments. These results suggest that ginsenoside-Rg1, synergized with voluntary running, may have higher efficacy in the treatment of depression through anti-inflammation and the improvement of neuroplasticity. These findings may provide a new perspective for the development of a therapeutic strategy for depression.