Effects of interleukin-1beta polymorphisms on brain function and behavior in healthy and psychiatric disease conditions

Ethanol drinking sex-dependently alters cortical IL-1β synaptic signaling and cognitive behavior in mice

Individuals with alcohol use disorder (AUD) struggle with inhibitory control, decision making, and emotional processing. These cognitive symptoms reduce treatment adherence, worsen clinical outcomes, and promote relapse. Neuroimmune activation is a key factor in the pathophysiology of AUD, and targeting this modulatory system is less likely to produce unwanted side effects compared to directly targeting neurotransmitter dysfunction. Notably, the cytokine interleukin-1β (IL-1β) has been broadly associated with the cognitive symptoms of AUD, though the underlying mechanisms are not well understood. Here we investigated how chronic intermittent 24-hour access two bottle choice ethanol drinking affects medial prefrontal cortex (mPFC)-related cognitive function and IL-1 synaptic signaling in male and female C57BL/6J mice. In both sexes, ethanol drinking decreased reference memory and increased mPFC IL-1 receptor 1 (IL-1R1) mRNA levels. In neurons, IL-1β can activate either pro-inflammatory or neuroprotective intracellular pathways depending on the isoform of the accessory protein (IL-1RAcP) recruited to the IL-1R1 complex. Moreover, ethanol drinking sex-dependently shifted mPFC IL-1RAcP isoform gene expression and IL-1β regulation of mPFC GABA synapses, both of which may contribute to female mPFC resiliency and male mPFC susceptibility. This type of signaling bias has become a recent focus of rational drug development. Therefore, in addition to increasing our understanding of how IL-1β sex-dependently contributes to mPFC dysfunction in AUD, our current findings also support the development of a new class of pharmacotherapeutics based on biased IL-1 signaling.

Baicalin Ameliorates Depression-like Behaviors via Inhibiting Neuroinflammation and Apoptosis in Mice

Depression is a common neuropsychiatric disease which brings an increasing burden to all countries globally. Baicalin, a flavonoid extracted from the dried roots of Scutellaria, has been reported to exert anti-inflammatory, antioxidant, and neuroprotective effects in the treatment of depression. However, the potential biological mechanisms underlying its antidepressant effect are still unclear. In the present study, we conducted extensive research on the potential mechanisms of baicalin's antidepressant effect using the methods of network pharmacology, including overlapped terms-based analysis, protein-protein interaction (PPI) network topology analysis, and enrichment analysis. Moreover, these results were further verified through molecular docking, weighted gene co-expression network analysis (WGCNA), differential gene expression analysis, and subsequent animal experiments. We identified forty-one genes as the targets of baicalin in the treatment of depression, among which AKT1, IL6, TP53, IL1B, and CASP3 have higher centrality in the more core position. Meanwhile, the roles of peripheral genes derived from direct potential targets were also observed. Our study suggested that biological processes, such as inflammatory reaction, apoptosis, and oxidative stress, may be involved in the therapeutic process of baicalin on depression. These mechanisms were validated at the level of structure, gene, protein, and signaling pathway in the present study. Taken together, these findings propose a new perspective on the potential mechanisms underlying baicalin's antidepressant effect, and also provide a new basis and clarified perspective for its clinical application.

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.

Prenatal maternal Inflammation, childhood cognition and adolescent depressive symptoms

BACKGROUND

Accumulating evidence indicates that higher prenatal maternal inflammation is associated with increased depression risk in adolescent and adult-aged offspring. Prenatal maternal inflammation (PNMI) may increase the likelihood for offspring to have lower cognitive performance, which, in turn, may heighten risk for depression onset. Therefore, this study explored the potential mediating role of childhood cognitive performance in the relationship between PNMI and adolescent depressive symptoms in offspring.

METHODS

Participants included 696 mother-offspring dyads from the Child Health and Development Studies (CHDS) cohort. Biomarkers of maternal inflammation [interleukin (IL)-6, IL-8, IL-1 receptor antagonist (IL-1RA) and soluble TNF receptor-II (sTNF-RII)] were assayed from first (T1) and second trimester (T2) sera. Childhood (ages 9-11) cognitive performance was assessed via standardized Peabody Picture Vocabulary Test (PPVT), a measure of receptive vocabulary correlated with general intelligence. Adolescent (ages 15-17) depressive symptoms were assessed via self-report.

RESULTS

There were no significant associations between T1 biomarkers and childhood PPVT or adolescent depressive symptoms. Higher T2 IL1-RA was directly associated with lower childhood PPVT (b = -0.21, SE = 0.08, t = -2.55, p = 0.01), but not with adolescent depressive symptoms. T2 IL-6 was not directly associated with childhood PPVT, but higher T2 IL-6 was directly associated at borderline significance with greater depressive symptoms in adolescence (b = 0.05, SE = 0.03, t = 1.96, p = 0.05). Lower childhood PPVT predicted significantly higher adolescent depressive symptoms (b = -0.07, SE = 0.02, t = -2.99, p < 0.01). There was a significant indirect effect of T2 IL-1RA on adolescent depressive symptoms via childhood PPVT (b = 0.03, 95 % CI = 0.002-0.03) indicating a partially mediated effect. No significant associations were found with T2 sTNF-RII nor IL-8.

CONCLUSIONS

Lower childhood cognitive performance, such as that indicated by a lower PPVT score, represents a potential mechanism through which prenatal maternal inflammation contributes to adolescent depression risk in offspring.

Modified Danzhi XiaoyaoSan inhibits neuroinflammation via regulating TRIM31/NLRP3 inflammasome in the treatment of CUMS depression

The NLRP3 inflammasome is critically involved in the development of depression. The E3 ubiquitin ligase TRIM31 negatively regulates this process by promoting the degradation of NLRP3 through the ubiquitin-proteasome pathway. Modified Danzhi Xiaoyaosan (MDZXYS) has shown good therapeutic effect in both preclinical and clinical depression treatments, yet the underlying mechanisms of its antidepressant effects are not fully understood. In the present study, we aimed to explore the antidepressant mechanisms of MDZXYS, focusing on NLRP3 activation and ubiquitin-mediated degradation. We employed rats with depression induced by chronic unpredictable mild stress (CUMS) and conducted various behavioral tests, including the sucrose preference, forced swimming, and open field tests. Neuronal damage in CUMS-treated rats was assessed using Nissl staining. We measured proinflammatory cytokine levels using ELISA kits and analyzed NLRP3/TRIM31 protein expression via Western blotting and immunofluorescence staining. Our results disclosed that MDZXYS reversed CUMS-induced depression-like behaviors in rats, reduced proinflammatory cytokine levels (IL-1β), and ameliorated neuronal damage in the prefrontal cortex. Additionally, CUMS activated the NLRP3 inflammasome in the prefrontal cortex and upregulated the protein expression of TRIM31. After MDZXYS administration, the expression of NLRP3 inflammasome-associated proteins was reduced, while the expression level of TRIM31 was further increased. Through co-localized immunofluorescence staining, we observed a significant elevation in the co-localization expression of NLRP3 and TRIM31 in the prefrontal cortex of the MDZXYS group. These findings suggest that inhibiting NLRP3 inflammasome-mediated neuroinflammation by modulating the TRIM31signaling pathway may underlie the antidepressant effects of MDZXYS, and further support targeting NLRP3 as a novel approach for the prevention and treatment of depression.

919 granules improve postpartum depression through the regulation of abnormal peripheral blood IL-1β

Postpartum depression (PPD) has a significant impact on the physical and mental health of mothers, potentially leading to symptoms such as low mood, fatigue, and decreased appetite. It may also affect the healthy growth of the infant. The onset of PPD is closely related to abnormalities in inflammation and the immune system. PPD patients exhibit abnormalities in the proportion of peripheral blood immune cells, along with an increase in pro-inflammatory cytokines. Excessive pro-inflammatory cytokines in peripheral blood can disrupt the blood-brain barrier (BBB) by activating astrocytes and reducing transendothelial electrical resistance (TEER), allowing peripheral immune cells or cytokines to enter the brain and trigger inflammation, ultimately leading to the onset of depression. In addition, PPD lacks safe and effective treatment medications. In this study, we collected peripheral blood from both healthy postpartum women and those with PPD, conducted single cell RNA sequencing (scRNA-seq), and used an in-house analytical tool scSTAR to reveal that PPD patients exhibit elevated proportions of peripheral blood cDC2 and Proliferation B cells, which are significantly correlated with IL-1β. Additionally, animal experiments were designed to validate that 919 granules can improve PPD by modulating the levels of peripheral blood IL-1β, providing a potential therapeutic mechanism for PPD treatment.

IL-1β, the first piece to the puzzle of sepsis-related cognitive impairment?

Sepsis is a leading cause of death resulting from an uncontrolled inflammatory response to an infectious agent. Multiple organ injuries, including brain injuries, are common in sepsis. The underlying mechanism of sepsis-associated encephalopathy (SAE), which is associated with neuroinflammation, is not yet fully understood. Recent studies suggest that the release of interleukin-1β (IL-1β) following activation of microglial cells plays a crucial role in the development of long-lasting neuroinflammation after the initial sepsis episode. This review provides a comprehensive analysis of the recent literature on the molecular signaling pathways involved in microglial cell activation and interleukin-1β release. It also explores the physiological and pathophysiological role of IL-1β in cognitive function, with a particular focus on its contribution to long-lasting neuroinflammation after sepsis. The findings from this review may assist healthcare providers in developing novel interventions against SAE.

A systematic strategy for investigating the pharmacological effects and mechanism of traditional Chinese medicinal formula: Guilin Xiguashuang as a case

BACKGROUND

Traditional Chinese medicinal formula (TCMF) has specific advantages in treating diseases. However, the pharmacological effects and mechanism of TCMF composed of traditional Chinese medicines (TCM) with unclear active components or targets have not yet been fully elucidated.

OBJECTIVES

This research proposed a strategy for elucidating the pharmacological effects and mechanism to address this issue systematically.

METHODS

With Guilin Xiguashuang (GLXGS) taken as a case, this study newly provided the multi-level assays, which decomposes TCMF into components, TCM, and TCMF levels. The main pharmacological effects were acquired through a comprehensive analysis based on the active components, pharmacological effects of TCM, and clinical efficacy of TCMF, respectively. The core targets and pathways were further identified and verified to elucidate the mechanism.

RESULTS

The main pharmacological effects of GLXGS were anti-inflammatory, analgesic, antibacterial, immunoregulatory, and wound healing. Moreover, the mechanism analysis demonstrated that GLXGS was involved in the regulation of NF-κB and VEGF signaling pathways and core targets, such as IL-6 and TNF-α. Finally, unproven immunomodulatory and anti-inflammatory mechanism were verified using RAW264.7 and THP-1 cells. GLXGS was verified to down-regulate IL-6, IL-1β, TNF-α, and CD86 in lipopolysaccharides-stimulated RAW264.7 cells, while enhancing polarization in both RAW264.7 and THP-1 cells, which were consistent with analysis results.

CONCLUSION

The present research provides a systematic strategy for the pharmacological effect prediction and mechanism analysis of TCMF, which is of great significance for studying complex TCMF.

The effect of Vortioxetine on the NLRP3 pathway and microglial activity in the prefrontal cortex in an experimental model of depression

BACKGROUND

Increasing evidence suggests that early life stress (ELS) and neuroinflammation are associated with the pathophysiology of depression. The purpose of this study was to determine the effects of Vortioxetine (VOR), a novel antidepressant, on ELS-induced behavioral changes and neuroinflammation.

METHOD

Wistar Albino 4-week-old male rats were divided into four groups: control; chronic unpredictable stress (CUMS), VOR, CUMS + VOR. Neurobehavioral assessment was performed on the first, 21st, and 42nd days. RT-PCR was used to detect the expression of P2X7, NLRP3, IL1β, IL18 in the prefrontal cortex. To assess the microglial activities of the prefrontal cortex, immunohistochemically stained CD68, and leukocyte common antigen (LCA) preparations were scanned with Manual WSI software, Basler camera, and scored.

RESULT AND DISCUSSION

Exposure to CUMS was associated with depression and anxiety-like behaviors, and administration of VOR led to improvement in these behaviors. NLRP3, IL-1β, and IL-18 were shown to be upregulated in the prefrontal cortex of CUMS rats, while their high expression was inhibited by VOR treatment. CD68 and LCA expressions were significantly higher in the CUMS group compared to the other groups.

CONCLUSION

According to these results, it may be considered that NLRP3 inflammasome-associated neuroinflammatory response and microglial activation may play a role in the etiopathogenesis of ELS.

Machine learning and experiments revealed a novel pyroptosis-based classification linked to diagnosis and immune landscape in spinal cord injury

Background

Rising evidence indicates the development of pyroptosis in the initiation and pathogenesis of spinal cord injury (SCI). However, the associated effects of pyroptosis-related genes (PRGs) in SCI are unclear.

Methods

We obtained the gene expression profiles of SCI and normal samples in the GEO.

Database

The R package limma screened for differentially expressed (DE) PRGs and performed functional enrichment analysis. Mechanical learning and PPI analysis helped filter essential PRGs to diagnose SCI. Peripheral blood was collected for validation from ten SCI patients and eight healthy individuals. The association of essential PRGs with immune infiltration was evaluated, and pyroptosis subtypes were recognized in SCI patients by unsupervised cluster analysis. Besides, a SCI model was built for in vivo validation of essential PRGs.

Result

We identified 25 DE-PRGs between SCI and normal controls. Functional enrichment analysis revealed the principal involvement of DE-PRGs in pyroptosis, inflammasome complex, interleukin-1 beta production, etc. Subsequently, three essential PRGs were identified and validated, showing excellent diagnostic efficacy and significant correlation with immune cell infiltration. Additionally, we developed diagnostic nomograms to predict the occurrence of SCI. Two pyroptosis subtypes exhibited distinct biological functions and immune landscapes among SCI patients. Finally, the expression of these essential PRGswas verified in vivo.

Conclusion

The current study described the vital effects of pyroptosis-related genes in SCI, providing a novel direction for effective assessment and management of SCI.

Abnormal expression of miR-3653-3p, caspase 1, IL-1β in peripheral blood of schizophrenia

Schizophrenia (SCZ) is a chronic, highly relapsing, severe mental disorder with an unclear etiology. Cytokine-mediated neuroimmune abnormalities have been repeatedly revealed. IL-1β was reported to play a vital role in expanding the inflammatory response. However, the underlying molecular mechanism is poorly understood. In this study, we found that miR-3653-3p with the NLRP3 binding site in Targetscan was differentially expressed in miRNA high-throughput sequencing in schizophrenia (SCZ), and indeed, its downregulation in SCZ peripheral blood was also verified by RT-qPCR (P-value = 0.015). Furthermore, we found that the mRNAs of caspase 1 and IL-1β are elevated in people who suffer from SCZ (P = 0.044 and P = 0.001, respectively). Moreover, the interaction of NLRP3, Caspase1, and IL-1β was found in the peripheral blood of patients with SCZ. The expression level of miR-3653-3p was negatively correlated with NLRP3 and IL-1β mRNA contents (r = 0.487, P = 0.04 and r = 0.508, P = 0.037, respectively). NLRP3 mRNA was positively correlated with caspase1 mRNA. Meanwhile, the expression of miR-3653-3p was also negatively correlated with negative symptom subscores of PANSS (r = 0.450, P = 0.046). IL-1β mRNA is positively correlated with the total scores of PANSS (r = 0.690, P = 0.002) and the sub-scores of general psychopathology of PANSS (r = 0.583, P = 0.014). Additionally, a significant positive relationship exists between IL-1β and the total duration (r = 0.638, P = 0.006). We found that the combination of miR-3653-3p, caspase 1, and IL-1β have better diagnostic values. The results indicate that miR-3653-3p, caspase 1, and IL-1β can potentially be biomarkers of SCZ, identifying negative symptoms or a chronic course. A further understanding of the involvement of IL-1β in SCZ may be a crucial molecular effector for the chronic course to intervene.

Inflammasome assembly in neurodegenerative diseases

Neurodegenerative disorders are characterized by the progressive dysfunction and death of selectively vulnerable neuronal populations, often associated with the accumulation of aggregated host proteins. Sustained brain inflammation and hyperactivation of inflammasome complexes have been increasingly demonstrated to contribute to neurodegenerative disease progression. Here, we review molecular mechanisms leading to inflammasome assembly in neurodegeneration. We focus primarily on four degenerative brain disorders in which inflammasome hyperactivation has been well documented: Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and the spectrum of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We discuss shared and divergent principles of inflammasome assembly across these disorders, and underscore the differences between neurodegeneration-associated inflammasome activation pathways and their peripheral-immune counterparts. We examine how aberrant assembly of inflammasome complexes may amplify pathology in neurodegeneration, including misfolded protein aggregation, and highlight prospects for neurotherapeutic interventions based on targeting inflammasome pathways.

Inflammasomes: Mechanisms of Action and Involvement in Human Diseases

Inflammasome complexes and their integral receptor proteins have essential roles in regulating the innate immune response and inflammation at the post-translational level. Yet despite their protective role, aberrant activation of inflammasome proteins and gain of function mutations in inflammasome component genes seem to contribute to the development and progression of human autoimmune and autoinflammatory diseases. In the past decade, our understanding of inflammasome biology and activation mechanisms has greatly progressed. We therefore provide an up-to-date overview of the various inflammasomes and their known mechanisms of action. In addition, we highlight the involvement of various inflammasomes and their pathogenic mechanisms in common autoinflammatory, autoimmune and neurodegenerative diseases, including atherosclerosis, rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, Alzheimer's disease, Parkinson's disease, and multiple sclerosis. We conclude by speculating on the future avenues of research needed to better understand the roles of inflammasomes in health and disease.

The role of signaling crosstalk of microglia in hippocampus on progression of ageing and Alzheimer's disease

Based on single-cell sequencing of the hippocampi of 5× familiar Alzheimer's disease (5× FAD) and wild type mice at 2-, 12-, and 24-month of age, we found an increased percentage of microglia in aging and Alzheimer's disease (AD) mice. Blood brain barrier injury may also have contributed to this increase. Immune regulation by microglia plays a major role in the progression of aging and AD, according to the functions of 41 intersecting differentially expressed genes in microglia. Signaling crosstalk between C-C motif chemokine ligand (CCL) and major histocompatibility complex-1 bridges intercellular communication in the hippocampus during aging and AD. The amyloid precursor protein (APP) and colony stimulating factor (CSF) signals drive 5× FAD to deviate from aging track to AD occurrence among intercellular communication in hippocampus. Microglia are involved in the progression of aging and AD can be divided into 10 functional types. The strength of the interaction among microglial subtypes weakened with aging, and the CCL and CSF signaling pathways were the fundamental bridge of communication among microglial subtypes.

Chronic ethanol induces a pro-inflammatory switch in interleukin-1β regulation of GABAergic signaling in the medial prefrontal cortex of male mice

Neuroimmune pathways regulate brain function to influence complex behavior and play a role in several neuropsychiatric diseases, including alcohol use disorder (AUD). In particular, the interleukin-1 (IL-1) system has emerged as a key regulator of the brain's response to ethanol (alcohol). Here we investigated the mechanisms underlying ethanol-induced neuroadaptation of IL-1β signaling at GABAergic synapses in the prelimbic region of the medial prefrontal cortex (mPFC), an area responsible for integrating contextual information to mediate conflicting motivational drives. We exposed C57BL/6J male mice to the chronic intermittent ethanol vapor-2 bottle choice paradigm (CIE-2BC) to induce ethanol dependence, and conducted ex vivo electrophysiology and molecular analyses. We found that the IL-1 system regulates basal mPFC function through its actions at inhibitory synapses on prelimbic layer 2/3 pyramidal neurons. IL-1β can selectively recruit either neuroprotective (PI3K/Akt) or pro-inflammatory (MyD88/p38 MAPK) mechanisms to produce opposing synaptic effects. In ethanol naïve conditions, there was a strong PI3K/Akt bias leading to a disinhibition of pyramidal neurons. Ethanol dependence produced opposite IL-1 effects - enhanced local inhibition via a switch in IL-1β signaling to the canonical pro-inflammatory MyD88 pathway. Ethanol dependence also increased cellular IL-1β in the mPFC, while decreasing expression of downstream effectors (Akt, p38 MAPK). Thus, IL-1β may represent a key neural substrate in ethanol-induced cortical dysfunction. As the IL-1 receptor antagonist (kineret) is already FDA-approved for other diseases, this work underscores the high therapeutic potential of IL-1 signaling/neuroimmune-based treatments for AUD.

Association of time spent in outdoor light and genetic risk with the incidence of depression

Depression is the consequence of both environment and genes working together. Genetic factors increase depression risk, but it is unclear whether this association can be offset by time spent in outdoor light. The study was undertaken to investigate the optimal time spent in outdoor light for lowering the risk of depression and the joint association of time spent in outdoor light and depression genetic risk. In UK Biobank, 380,976 depression-free individuals were included in this study. Polygenic risk score (PRS) was categorized into three groups in terms of tertiles. Time spent in outdoor light on a typical day in summer or winter originated from the questionnaire survey. Depression was defined as hospital admission. The potential dose-response relationship between time spent in outdoor light and depression risk was shown by a restricted cubic spline. Data were analyzed using Cox regressions and Laplace regression. After the median follow-up of 12.6 years, 13,636 individuals suffered from depression in the end. A nonlinear (J-shaped relationship) trend was observed between time spent in outdoor light and depression risk. On average, 1.5 h/day of outdoor light was related to the minimum risk of depression. Individuals below and above this optimal time both had elevated depression risk (below, HR = 1.09, 95% CI: 1.02-1.16; above, HR = 1.13, 95% CI: 1.07-1.20), and the time to incident depression were both shortened by 0.46 years (50th percentile differences [PD] = -0.46, 95% CI: -0.78, -0.14) and 0.63 years (50th PD = -0.63, 95% CI: -0.90, -0.35) years, respectively. In a comparison of individuals with the lowest tertile of PRS and average 1.5 h/day outdoor light, the HRs and 95% CIs of depression were 1.36 (1.21-1.53) and 1.43 (1.29-1.58) in those with the highest tertile of PRS and below/above this reference value, respectively. Significant multiplicative interactions were observed between intermediate genetic risks and longer time spent in outdoor light. We found that an average of 1.5 h/day spent in outdoor light was associated with a lower depression risk whatever the degree of depression genetic predisposition. Moderate time spent in outdoor light may contribute to a decreased depression risk even among people with a higher genetic risk of depression.

Bi-Directional Relationship Between Autophagy and Inflammasomes in Neurodegenerative Disorders

The innate immune system, as the first line of cellular defense, triggers a protective response called inflammation when encountered with invading pathogens. Inflammasome is a multi-protein cytosolic signaling complex that induces inflammation and is critical for inflammation-induced pyroptotic cell death. Inflammasome activation has been found associated with neurodegenerative disorders (NDs), inflammatory diseases, and cancer. Autophagy is a crucial intracellular quality control and homeostasis process which removes the dysfunctional organelles, damaged proteins, and pathogens by sequestering the cytosolic components in a double-membrane vesicle, which eventually fuses with lysosome resulting in cargo degradation. Autophagy disruption has been observed in many NDs presented with persistent neuroinflammation and excessive inflammasome activation. An interplay between inflammation activation and the autophagy process has been realized over the last decade. In the case of NDs, autophagy regulates neuroinflammation load and cellular damage either by engulfing the misfolded protein deposits, dysfunctional mitochondria, or the inflammasome complex itself. A healthy two-way regulation between both cellular processes has been realized for cell survival and cell defense during inflammatory conditions. Therefore, clinical interest in the modulation of inflammasome activation by autophagy inducers is rapidly growing. In this review, we discuss the structural basis of inflammasome activation and the mechanistic ideas of the autophagy process in NDs. Along with comments on multiple ways of neuroinflammation regulation by microglial autophagy, we also present a perspective on pharmacological opportunities in this molecular interplay pertaining to NDs.

Selected Biomarkers of Depression: What Are the Effects of Cytokines and Inflammation?

Depression is one of the leading mental illnesses worldwide and lowers the quality of life of many. According to WHO, about 5% of the worldwide population suffers from depression. Newer studies report a staggering global prevalence of 27.6%, and it is rising. Professionally, depression belonging to affective disorders is a psychiatric illness, and the category of major depressive disorder (MDD) comprises various diagnoses related to persistent and disruptive mood disorders. Due to this fact, it is imperative to find a way to assess depression quantitatively using a specific biomarker or a panel of biomarkers that would be able to reflect the patients' state and the effects of therapy. Cytokines, hormones, oxidative stress markers, and neuropeptides are studied in association with depression. The latest research into inflammatory cytokines shows that their relationship with the etiology of depression is causative. There are stronger cytokine reactions to pathogens and stressors in depression. If combined with other predisposing factors, responses lead to prolonged inflammatory processes, prolonged dysregulation of various axes, stress, pain, mood changes, anxiety, and depression. This review focuses on the most recent data on cytokines as markers of depression concerning their roles in its pathogenesis, their possible use in diagnosis and management, their different levels in bodily fluids, and their similarities in animal studies. However, cytokines are not isolated from the pathophysiologic mechanisms of depression or other psychiatric disorders. Their effects are only a part of the whole pathway.

Mechanisms of Panax Ginseng on Treating Sepsis by RNA-Seq Technology

Purpose

To explore the potential active targets and mechanisms of Panax Ginseng in the treatment of sepsis using network pharmacology and RNA-seq technology.

Patients and Methods

Patients with sepsis and healthy volunteers were collected according to SEPSIS 3.0, and their peripheral blood was used for RNA-seq analysis. The active ingredients and targets of Panax Ginseng were obtained using the TCMSP database, PPI and GO analysis were performed for disease-drug intersection targets. Then, we used Meta-analysis to screen core genes. Finally, single-cell RNA-seq was used to perform cell localization analysis on core genes.

Results

RNA-seq analysis collected 4521 sepsis-related genes, TCMSP database obtained 86 Panax Ginseng active ingredients and their 294 active targets. PPI and GO analysis showed intersection targets were closely linked, and mainly involved in cellular response to chemical stress, response to drug and molecule of bacterial origin, etc. Then, core targets, IL1B, ALOX5, BCL2 and IL4R, were sorted by Meta-analysis, and all four genes have high expression in the sepsis survivor group compared to the sepsis non-survivor group; single-cell RNA-seq revealed that IL1B was mainly localized in macrophages, ALOX5 was mainly localized in macrophages and B cells, BCL2 was mainly localized in natural killer cells, T cells and B cells, IL4R was widely distributed in immune cells. Finally, according to the correspondence between the active ingredients and targets of Panax Ginseng in TCMSP database, we found that Ginsenoside rh2 regulates the expression of IL1B, Ginsenoside rf regulates the expression of IL1B and IL4R, Kaempferol regulates the expression of ALOX5 and BCL2, and β-sitosterol regulates the expression of BCL2.

Conclusion

Ginsenoside rh2, Ginsenoside rf, Kaempferol and β-sitosterol may produce anti-sepsis effects by regulating the expression of IL1B, ALOX5, BCL2 and IL4R, thus improving the survival rate of sepsis patients.

Interface inhibitory action on Interleukin-1β using selected anti-inflammatory compounds to mitigate the depression: A computational investigation

Interleukin-1β (IL1β) is a keynote mediator of inflammation with diverse physiological functions, playing a fundamental role in memory and mood regulation. The pleiotropic effects of IL-1β have been proposed to be implicated in the pathogenesis and etiology of depression. Thus, targeting IL-1β offers an inimitable opportunity to develop new strategies for an alternative therapy to treat depression. The focus of this study is to find out the potential inhibitors against IL-1β. Since, there is no oral specific drug reported yet thus, demanding an urgent need to develop new immunomodulatory drugs to combat chronic diseases. In this study, ligand-based pharmacophore modeling integrated with virtual screening and molecular docking strategy was designed to identify novel compounds capable of inhibiting the interactions towards cognitive receptor IL-1RI. In this connection, a set of 30,000 compounds were screened by a developed pharmacophore model that led to the retrieval of 2043 molecules from the in-house library and ZINC Database. Primarily, specific binding regions for IL-1β inhibitors have been explored by blind docking studies. After the selection of the binding site, the hits identified as actives based on the 3D-pharmacophore model were assessed by molecular docking studies. In a stepwise screening, six potential virtual hits were shortlisted for molecular dynamic simulation to acquire insights into their dynamic behavior. The obtained results highlighted that these compounds are stabilized in the targeted pocket of IL-1β and possibly block the formation of an active heterocomplex, subsequently locking the associated signaling cascade. Further in vitro experiments confirmed the inhibitory potential of Compound-157 and compound-283 with the IC₅₀ of 1.6 ± 0.1 and 9.1 ± 1.7 µg/mL respectively.

Supramolecular organizing centers at the interface of inflammation and neurodegeneration

The pathogenesis of neurodegenerative diseases involves the accumulation of misfolded protein aggregates. These deposits are both directly toxic to neurons, invoking loss of cell connectivity and cell death, and recognized by innate sensors that upon activation release neurotoxic cytokines, chemokines, and various reactive species. This neuroinflammation is propagated through signaling cascades where activated sensors/receptors, adaptors, and effectors associate into multiprotein complexes known as supramolecular organizing centers (SMOCs). This review provides a comprehensive overview of the SMOCs, involved in neuroinflammation and neurotoxicity, such as myddosomes, inflammasomes, and necrosomes, their assembly, and evidence for their involvement in common neurodegenerative diseases. We discuss the multifaceted role of neuroinflammation in the progression of neurodegeneration. Recent progress in the understanding of particular SMOC participation in common neurodegenerative diseases such as Alzheimer's disease offers novel therapeutic strategies for currently absent disease-modifying treatments.

Association between Ultraviolet B Exposure Levels and Depression in Taiwanese Adults: A Nested Case-Control Study

Depression is a common mental disorder that affects more than 264 million people worldwide. Anxiety, diabetes, Alzheimer's disease, myocardial infarction, and cancer, among other disorders, are known to increase the risk of depression. Exposure to ultraviolet B (UVB) can cause human serotonin levels to increase. The vitamin D pathway is one mechanism through which ultraviolet light absorbed through the skin can affect mood; however, UVB exposure is known to increase the risk of cancer. In this study, we explored the effects of prolonged exposure to UVB on depression. Data were retrieved from the Taiwan National Health Insurance Research Database for 2008 to 2013. Each patient with depression was matched 1:4 with a comparison patient by sex and age (±5 years); thus, the study included 23,579 patients with depression and 94,316 healthy controls for comparison. The patients had been exposed to UVB for at least 1 year to observe the cumulative effect of UVB exposure. Based on the World Health Organization UV index, we divided the observation period data into five UV levels: low, moderate, high, very high, and extreme. A multivariate Poisson regression model was used to assess the risk of depression according to UVB exposure level, adjusting for sex, age, income, urbanization level, month, and comorbidities. The results revealed that the incidence rate ratio (IRR) for patients with depression was 0.889 for moderate levels (95% CI 0.835-0.947), 1.134 for high levels (95% CI: 1.022-1.260), 1.711 for very high levels (95% CI: 1.505-1.945), and 2.785 for extreme levels (95% CI: 2.439-3.180) when compared to low levels. Moderate levels of UVB lowered the risk of depression, while high levels of UVB gradually increased the risk. We propose that UVB at normal concentrations can effectively improve depression. However, exposure to high concentrations of UVB damage DNA results in physical diseases such as skin cancer, which increase the risk of depression.

The relationship between immune and cognitive dysfunction in mood and psychotic disorder: a systematic review and a meta-analysis

BACKGROUND

In psychotic and mood disorders, immune alterations are hypothesized to underlie cognitive symptoms, as they have been associated with elevated blood levels of inflammatory cytokines, kynurenine metabolites, and markers of microglial activation. The current meta-analysis synthesizes all available clinical evidence on the associations between immunomarkers (IMs) and cognition in these psychiatric illnesses.

METHODS

Pubmed, Web of Science, and Psycinfo were searched for peer-reviewed studies on schizophrenia spectrum disorder (SZ), bipolar disorder (BD), or major depressive disorder (MDD) including an association analysis between at least one baseline neuropsychological outcome measure (NP) and one IM (PROSPERO ID:CRD42021278371). Quality assessment was performed using BIOCROSS. Correlation meta-analyses, and random effect models, were conducted in Comprehensive Meta-Analysis version 3 investigating the association between eight cognitive domains and pro-inflammatory and anti-inflammatory indices (PII and AII) as well as individual IM.

RESULTS

Seventy-five studies (n = 29,104) revealed global cognitive performance (GCP) to be very weakly associated to PII (r = -0.076; p = 0.003; I² = 77.4) or AII (r = 0.067; p = 0.334; I² = 38.0) in the combined patient sample. Very weak associations between blood-based immune markers and global or domain-specific GCP were found, either combined or stratified by diagnostic subgroup (GCP x PII: SZ: r = -0.036, p = 0.370, I² = 70.4; BD: r = -0.095, p = 0.013, I² = 44.0; MDD: r = -0.133, p = 0.040, I² = 83.5). We found evidence of publication bias.

DISCUSSION

There is evidence of only a weak association between blood-based immune markers and cognition in mood and psychotic disorders. Significant publication and reporting biases were observed and most likely underlie the inflation of such associations in individual studies.

Depression and obesity among females, are sex specificities considered?

This study aimed to systematically review the relationship of obesity-depression in the female sex. We carried out a systematic search (PubMed, MEDLINE, Embase) to quantify the articles (controlled trials and randomized controlled trials) regarding obesity and depression on a female population or a mixed sample. Successively, we established whether the sex specificities were studied by the authors and if they reported on collecting data regarding factors that may contribute to the evolution of obesity and depression and that could be responsible for the greater susceptibility of females to those conditions. After applying the inclusion and exclusion criteria, we found a total of 20 articles with a female sample and 54 articles with a mixed sample. More than half of all articles (51.35%, n = 38) evaluated the relationship between depression and obesity, but only 20 (27.03%) evaluated this relationship among females; still, 80% of those (n = 16) presented supporting results. However, few articles considered confounding factors related to female hormones (12.16%, n = 9) and none of the articles focused on factors responsible for the binomial obesity-depression in the female sex. The resulting articles also supported that depression (and related impairments) influencing obesity (and related impairments) is a two-way road. This systematic review supports the concurrency of obesity-depression in females but also shows how sex specificities are ultimately under-investigated. Female sex specificity is not being actively considered when studying the binomial obesity-depression, even within a female sample. Future studies should focus on trying to understand how the female sex and normal hormonal variations influence these conditions.

The Potential Role of Cytokines and Growth Factors in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is one of the most prominent neurodegenerative diseases, which impairs cognitive function in afflicted individuals. AD results in gradual decay of neuronal function as a consequence of diverse degenerating events. Several neuroimmune players (such as cytokines and growth factors that are key players in maintaining CNS homeostasis) turn aberrant during crosstalk between the innate and adaptive immunities. This aberrance underlies neuroinflammation and drives neuronal cells toward apoptotic decline. Neuroinflammation involves microglial activation and has been shown to exacerbate AD. This review attempted to elucidate the role of cytokines, growth factors, and associated mechanisms implicated in the course of AD, especially with neuroinflammation. We also evaluated the propensities and specific mechanism(s) of cytokines and growth factors impacting neuron upon apoptotic decline and further shed light on the availability and accessibility of cytokines across the blood-brain barrier and choroid plexus in AD pathophysiology. The pathogenic and the protective roles of macrophage migration and inhibitory factors, neurotrophic factors, hematopoietic-related growth factors, TAU phosphorylation, advanced glycation end products, complement system, and glial cells in AD and neuropsychiatric pathology were also discussed. Taken together, the emerging roles of these factors in AD pathology emphasize the importance of building novel strategies for an effective therapeutic/neuropsychiatric management of AD in clinics.

The AST-120 Recovers Uremic Toxin-Induced Cognitive Deficit via NLRP3 Inflammasome Pathway in Astrocytes and Microglia

Chronic kidney disease (CKD) is characterized by the progressive loss of renal function; moreover, CKD progression commonly leads to multiple comorbidities, including neurological dysfunction and immune disorders. CKD-triggered neuroinflammation significantly contributes to cognitive impairment. This study aimed to investigate the contribution of uremic toxins to cognitive impairment. Serum creatinine, blood urea nitrogen (BUN), indoxyl sulfate (IS), and p-cresol sulfate (PCS) levels were measured using an enzyme-linked immunosorbent assay and high-performance liquid chromatography. The creatinine, BUN, IS, and PCS levels were increased from 4 weeks after 5/6-nephrectomy in mice, which suggested that 5/6-nephrectomy could yield a CKD animal model. Further, CKD mice showed significantly increased brain and serum indoxyl sulfate levels. Immunohistochemistry analysis revealed hippocampal inflammation and NLRP3-inflammasomes in astrocytes. Further, the Y-maze and Morris water maze tests revealed learning and memory defects in CKD mice. AST-120, which is also an IS absorbent, effectively reduced serum and hippocampal IS levels as well as reversed the cognitive impairment in CKD mice. Additionally, NLRP3-knockout mice that underwent 5/6-nephrectomy showed no change in cognitive function. These findings suggested that IS is an important uremic toxin that induces NLRP3 inflammasome-mediated not only in microglia, but it also occurred in astrocytic inflammation, which subsequently causes cognitive impairment.

Inflammatory biomarkers and cognitive functioning in individuals with euthymic bipolar disorder: exploratory study

BACKGROUND

Neurobiological research frequently implicates inflammatory and neurogenic components with core aspects of bipolar disorder. Even in periods of symptom remission (euthymia), individuals with bipolar disorder experience cognitive impairments, which are increasingly being proposed as an outcome for interventions; identifying biomarkers associated with cognitive impairment in people with bipolar disorder could advance progress in this therapeutic field through identifying biological treatment targets.

AIMS

We aimed to identify proteomic biomarker correlates of cognitive impairment in individuals with euthymic bipolar disorder.

METHOD

Forty-four adults with a bipolar disorder diagnosis in euthymia underwent a battery of cognitive assessments and provided blood for biomarkers. We examined a comprehensive panel of inflammatory and trophic proteins as putative cross-sectional predictors of cognition, conceptualised according to recommended definitions of clinically significant cognitive impairment (binary construct) and global cognitive performance (continuous measure).

RESULTS

A total of 48% of the sample met the criteria for cognitive impairment. Adjusting for potentially important covariates, regression analyses identified lower levels of three proteins as significantly and independently associated with cognitive deficits, according to both binary and continuous definitions (interleukin-7, vascular endothelial growth factor C and placental growth factor), and one positively correlated with (continuous) global cognitive performance (basic fibroblast growth factor).

CONCLUSIONS

This study identifies four candidate markers of cognitive impairment in bipolar disorder, none of which have been previously compared with cognitive function in participants with bipolar disorder. Pending replication in larger samples and support from longitudinal studies, these markers could have implications for treating cognitive dysfunction in this patient population.

Prolonged Chronic Stress and Persistent Iron Dysregulation Prevent Anemia Recovery Following Trauma

Introduction Following major trauma, persistent injury-associated anemia is associated with organ failure, increased length of stay and mortality. We hypothesize that prolonged adrenergic stimulation following trauma is directly responsible for persistent iron dysfunction that impairs anemia recovery. Materials and Methods Naïve rodents, lung contusion and hemorrhagic shock followed by daily handling for 13 d (LCHS), LCHS followed by 6 d of restraint stress and 7 d of daily handling (LCHS/CS-7) and LCHS/CS followed by 13 d of restraint stress with day and/or night disruption (LCHS/CS-14) were sacrificed on day 14. Hemoglobin, plasma, urine, bone marrow/liver inflammatory and erythropoietic markers were analyzed. Results LCHS/CS-14 led to a significant decline in weight gain and persistently elevated plasma and urine inflammatory markers. Liver IL-6, IL-1β and hepcidin expression were significantly increased following LCHS/CS-14. LCHS/CS-14 also had impaired anemia recovery with reduced plasma transferrin and erythropoietin receptor expression. Conclusion Prolonged chronic stress following trauma/hemorrhagic shock led to sustained inflammation with increased expression of IL-1β, IL-6 and hepcidin with decreased iron availability for uptake into erythroid progenitor cells and a lack of anemia recovery.

Associations of Serum Cytokine Levels and Interleukin-6-572C/G Polymorphism with Myelin Damage in Chinese Children with Autism Spectrum Disorder

Increasing evidence suggests that immunological disturbances and abnormalities in axonal myelination are involved in the pathophysiology of autism spectrum disorder (ASD). The present study aimed to determine the role of cytokines in myelin damage in Chinese children with ASD and the role of cytokine dysregulation, myelin damage, and cytokine polymorphisms in ASD in Chinese children. The present case-control study included 98 ASD subjects and 252 typically developing (TD) controls; the levels of serum cytokines and myelin basic protein (MBP) were determined using enzyme-linked immunosorbent assay. Cytokine polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. Autistic clinical manifestations were assessed by the Childhood Autism Rating Scale (CARS). The results showed that serum levels of interleukin (IL)-1β, IL-2R, IL-6, IL-8, and MBP were higher in children with ASD compared with those in TD children. In individuals with ASD, serum MBP level was significantly positively associated with the CARS total score, and serum levels of IL-1β, IL-2R, IL-6, and MBP demonstrated positive correlations. The data identified IL-6*MBP as a factor that influenced the risk of ASD, and IL-2R*MBP was identified as a factor that influenced symptom severity, which influenced auxiliary diagnosis of ASD. The presence of the interleukin-6-572CC genotype was associated with significantly higher serum levels of IL-6 and MBP but did not influence the risk and symptom severity of ASD. Therefore, the results suggested inflammatory responses and myelin damage in Chinese children with ASD. Cytokine dysregulation influenced myelin damage in ASD; moreover, the interactions of the cytokines and myelin damage influenced the risk and symptom severity of ASD. The IL-6-572C/G genotypes may be associated with myelin damage in ASD by influencing the circulating level of IL-6.

Role of interleukin 8 in depression and other psychiatric disorders

Low grade neuroinflammation has been suggested as one of the underlying mechanisms of many psychiatric diseases as well as cognitive disorders. Interleukin 8 (IL-8), a proinflammatory cytokine produced by many cell types including macrophage and microglia, mainly functions as a neutrophil chemoattractant in the bloodstream. IL-8 is also found in the brain, where it is released from microglia in response to proinflammatory stimuli. In this review, we highlight studies focusing on the role of IL-8 in psychiatric diseases such as major depression, bipolar disorder, schizophrenia, sleep disorder, autism spectrum disorder, anxiety disorders and dementia. Increased peripheral IL-8 levels have been reported in these diseases, particularly in schizophrenic disorder, bipolar disorder, obstructive sleep apnea and autism spectrum disorder. The literature on IL-8 and major depression is inconsistent. IL-8 has been found to be a factor associated with schizophrenic prognosis and therapeutic response, and may affect a wide range of symptomatology. Considering that the exact role of immune alterations is still under research, the success of immune-based therapies in psychiatric diseases is limited for the time being.

Evaluation of IL1B rs1143634 and IL6 rs1800796 Polymorphisms with Autism Spectrum Disorder in the Turkish Children

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder caused by genetic, environmental and immunological factors. It is known that neural development processes are affected by immune functions. The aim of this study is to evaluate the relationship between cytokines IL6 and IL1B gene polymorphisms in ASD.Methods: DNA isolations were performed in 95 children diagnosed with ASD and 84 unrelated healthy children, single-nucleotide changes in IL6 (rs1800796) and IL1B (rs1143634) genes were determined by using Real-Time PCR (Real-Time Polymerase Chain Reaction) method.Results: IL6 rs1800796 polymorphism presented an elevated risk for the development of ASD with CG genotype and dominant model (CG+GG vs. CC), CG+GG carriers (OR = 1.867, p = 0.057; OR = 1.847, p = 0.055, respectively). CT genotype in IL1B rs1143634 polymorphism associated with 2.33 times elevated risk of autism and showed a significant association compared to wild-type CC genotype (p = 0.02). IL1B rs1143634 polymorphism presented a significantly elevated risk for the development of ASD with recessive model (CC+CT vs.TT), TT genotype (OR = 8.145, p = 0.02).Conclusion: This study concludes that rs1143634 is associated with the risk of ASD in Turkish children. Determining these polymorphisms in a larger sample group may contribute to understanding the etiology of ASD and developing new treatment protocols.Abbreviations: ASD: Autism spectrum disorder; DNA: Deoxyribonucleic acid; IL6: Interleukin 6; IL1B: Interleukin 1 beta; Real-time PCR: Real-time polymerase chain reaction; JAK-STAT: The Janus kinase/signal transducers and activators of transcription; MAPK: The mitogen-activated protein kinase; 5'UTR: The 5' untranslated region; IL1α: Interleukin 1 alpha; IL-1Ra: Interleukin 1 receptor antagonist; NF-κB: Nuclear factor-kappa B; DSM-V: The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; M-CHAT: Modified Checklist for Autism in Toddlers; EDTA: Ethylenediaminetetraacetic acid; gDNA: Genomic DNA; HWE: Hardy-Weinberg equilibrium; ANK2: Ankyrin 2; NL3: Neuroligin-3; XRCC4: X-ray repair cross complementing 4.

CARD8 and IL1B Polymorphisms Influence MRI Brain Patterns in Newborns with Hypoxic-Ischemic Encephalopathy Treated with Hypothermia

Inflammation and oxidative stress are recognized as important contributors of brain injury in newborns due to a perinatal hypoxic-ischemic (HI) insult. Genetic variability in these pathways could influence the response to HI and the outcome of brain injury. The aim of our study was to evaluate the impact of common single-nucleotide polymorphisms in the genes involved in inflammation and response to oxidative stress on brain injury in newborns after perinatal HI insult based on the severity and pattern of magnetic resonance imaging (MRI) findings. The DNA of 44 subjects was isolated from buccal swabs. Genotyping was performed for NLRP3 rs35829419, CARD8 rs2043211, IL1B rs16944, IL1B rs1143623, IL1B rs1071676, TNF rs1800629, CAT rs1001179, SOD2 rs4880, and GPX1 rs1050450. Polymorphism in CARD8 was found to be protective against HI brain injury detected by MRI overall findings. Polymorphisms in IL1B were associated with posterior limb of internal capsule, basal ganglia, and white matter brain patterns determined by MRI. Our results suggest a possible association between genetic variability in inflammation- and antioxidant-related pathways and the severity of brain injury after HI insult in newborns.

Therapeutic role of inflammasome inhibitors in neurodegenerative disorders

Neuroinflammation, characterized by the activation of glial cells, is a hallmark in several neurological and neurodegenerative disorders. Inadequate inflammation cannot eliminate the infection of pathogens, while excessive or hyper-reactive inflammation can cause chronic or systemic inflammatory diseases affecting the central nervous system (CNS). In response to a brain injury or pathogen invasion, the pathogen recognition receptors (PRRs) expressed on glial cells are activated via binding to cellular damage-associated molecular patterns (DAMPs) or pathogen-associated molecular patterns (PAMPs). This subsequently leads to the activation of NOD (nucleotide-binding oligomerization domain)-like receptor proteins (NLRs). In neurodegenerative diseases such as HIV-1-associated neurocognitive disorders (HAND), Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), chronic inflammation is a critical contributing factor for disease manifestation including pathogenesis. Emerging evidence points to the involvement of "inflammasomes", especially the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) complex in the development of these diseases. The activated NLRP3 results in the proteolytic activation of caspase-1 that facilitates the cleavage of pro-IL-1β and the secretion of IL-1β and IL-18 proinflammatory cytokines. Accordingly, these and other seminal findings have led to the development of NLRP-targeting small-molecule therapeutics as possible treatment options for neurodegenerative disorders. In this review, we will discuss the new advances and evidence-based literature concerning the role of inflammasomes in neurodegenerative diseases, its role in the neurological repercussions of CNS chronic infection, and the examples of preclinical or clinically tested NLRP inhibitors as potential strategies for the treatment of chronic neurological diseases.

The Gut-Brain Axis: How Microbiota and Host Inflammasome Influence Brain Physiology and Pathology

The human microbiota has a fundamental role in host physiology and pathology. Gut microbial alteration, also known as dysbiosis, is a condition associated not only with gastrointestinal disorders but also with diseases affecting other distal organs. Recently it became evident that the intestinal bacteria can affect the central nervous system (CNS) physiology and inflammation. The nervous system and the gastrointestinal tract are communicating through a bidirectional network of signaling pathways called the gut-brain axis, which consists of multiple connections, including the vagus nerve, the immune system, and bacterial metabolites and products. During dysbiosis, these pathways are dysregulated and associated with altered permeability of the blood-brain barrier (BBB) and neuroinflammation. However, numerous mechanisms behind the impact of the gut microbiota in neuro-development and -pathogenesis remain poorly understood. There are several immune pathways involved in CNS homeostasis and inflammation. Among those, the inflammasome pathway has been linked to neuroinflammatory conditions such as multiple sclerosis, Alzheimer's and Parkinson's diseases, but also anxiety and depressive-like disorders. The inflammasome complex assembles upon cell activation due to exposure to microbes, danger signals, or stress and lead to the production of pro-inflammatory cytokines (interleukin-1β and interleukin-18) and to pyroptosis. Evidences suggest that there is a reciprocal influence of microbiota and inflammasome activation in the brain. However, how this influence is precisely working is yet to be discovered. Herein, we discuss the status of the knowledge and the open questions in the field focusing on the function of intestinal microbial metabolites or products on CNS cells during healthy and inflammatory conditions, such as multiple sclerosis, Alzheimer's and Parkinson's diseases, and also neuropsychiatric disorders. In particular, we focus on the innate inflammasome pathway as immune mechanism that can be involved in several of these conditions, upon exposure to certain microbes.

Enduring effects of an unhealthy diet during adolescence on systemic but not neurobehavioural measures in adult rats

Introduction: Adolescence is an important stage of maturation for various brain structures. It is during this time therefore that the brain may be more vulnerable to environmental factors such as diet that may influence mood and memory. Diets high in fat and sugar (termed a cafeteria diet) during adolescence have been shown to negatively impact upon cognitive performance, which may be reversed by switching to a standard diet during adulthood. Consumption of a cafeteria diet increases both peripheral and central levels of interleukin-1β (IL-1β), a pro-inflammatory cytokine which is also implicated in cognitive impairment during the ageing process. It is unknown whether adolescent exposure to a cafeteria diet potentiates the negative effects of IL-1β on cognitive function during adulthood.Methods: Male Sprague-Dawley rats consumed a cafeteria diet during adolescence after which time they received a lentivirus injection in the hippocampus to induce chronic low-grade overexpression of IL-1β. After viral integration, metabolic parameters, circulating and central pro-inflammatory cytokine levels, and cognitive behaviours were assessed.Results: Our data demonstrate that rats fed the cafeteria diet exhibit metabolic dysregulations in adulthood, which were concomitant with low-grade peripheral and central inflammation. Overexpression of hippocampal IL-1β in adulthood impaired spatial working memory. However, adolescent exposure to a cafeteria diet, combined with or without hippocampal IL-1β in adulthood did not induce any lasting cognitive deficits when the diet was replaced with a standard diet in adulthood. Discussion: These data demonstrate that cafeteria diet consumption during adolescence induces metabolic and inflammatory changes, but not behavioural changes in adulthood.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cumulative Influence of Inflammatory Response Genetic Variation on Long-Term Neurobehavioral Outcomes after Pediatric Traumatic Brain Injury Relative to Orthopedic Injury: An Exploratory Polygenic Risk Score

The addition of genetic factors to prognostic models of neurobehavioral recovery following pediatric traumatic brain injury (TBI) may account for unexplained heterogeneity in outcomes. The present study examined the cumulative influence of candidate genes involved in the inflammatory response on long-term neurobehavioral recovery in children with early childhood TBI relative to children with orthopedic injuries (OI). Participants were drawn from a prospective, longitudinal study evaluating outcomes of children who sustained TBI (n = 67) or OI (n = 68) between the ages of 3 and 7 years. Parents completed ratings of child executive function and behavior at an average of 6.8 years after injury. Exploratory unweighted and weighted polygenic risk scores (PRS) were constructed from single nucleotide polymorphisms (SNPs) across candidate inflammatory response genes (i.e., angiotensin converting enzyme [ACE], brain-derived neurotrophic factor [BDNF], interleukin-1 receptor antagonist [IL1RN], and 5'-ectonucleotidase [NT5E]) that showed nominal (p ≤ 0.20) associations with outcomes in the TBI group. Linear regression models tested the PRS × injury group (TBI vs. OI) interaction term and post-hoc analyses examined the effect of PRS within each injury group. Higher inflammatory response PRS were associated with more executive dysfunction and behavior problems in children with TBI but not in children with OI. The cumulative influence of inflammatory response genes as measured by PRS explained additional variance in long-term neurobehavioral outcomes, over and above well-established predictors and single candidate SNPs tested individually. The results suggest that some of the unexplained heterogeneity in long-term neurobehavioral outcomes following pediatric TBI may be attributable to a child's genetic predisposition to a greater or lesser inflammatory response to TBI.

Interleukin IL-1B gene polymorphism in Tunisian patients with chronic hepatitis B infection: Association with replication levels

Approaches based on association studies have proven useful in identifying genetic predictors for many diseases, including susceptibility to chronic hepatitis B. In this study we were interested by the IL-1B genetic variants that have been involved in the immune response and we analyzed their role in the susceptibility to develop chronic hepatitis B in the Tunisian population. IL-1B is a potent proinflammatory cytokine that plays an important role in inflammation of the liver. Polymorphic gene IL-1 (-511, +3954) was analyzed in a total of 476 individuals: 236 patients with chronic hepatitis B from different cities of Tunisia recruited in Pasteur Institute between January 2017 and December 2018 and 240 controls. Genomic DNA was obtained using the standard salting-out method and genotyping was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism. For -511C>T polymorphism a significant association was found between patients and controls when comparing the genotypic (P = 0.007; χ²  = 9.74 and odds ratio [OR] = 0.60; confidence interval [CI] = 0.41-0.89) and allelic (P = 0.001; χ²  = 10.60) frequencies. When the viral load was taken into account a highly significant difference was found (P = 9 × 10^-4 ; χ²  = 10.89). For +3954C>T polymorphism a significant association was found between patients and controls when comparing genotypic (P = 0.0058; χ²  = 7.60 and OR = 1.67; CI = 1.14-2.46) and allelic (P = 0.0029; χ²  = 8.81) frequencies. T allele can be used as a strong marker for hepatitis B virus disease for both polymorphisms.

Dysregulation of inflammation, neurobiology, and cognitive function in PTSD: an integrative review

Compelling evidence from animal and human research suggest a strong link between inflammation and posttraumatic stress disorder (PTSD). Furthermore, recent findings support compromised neurocognitive function as a key feature of PTSD, particularly with deficits in attention and processing speed, executive function, and memory. These cognitive domains are supported by brain structures and neural pathways that are disrupted in PTSD and which are implicated in fear learning and extinction processes. The disruption of these supporting structures potentially results from their interaction with inflammation. Thus, the converging evidence supports a model of inflammatory dysregulation and cognitive dysfunction as combined mechanisms underpinning PTSD symptomatology. In this review, we summarize evidence of dysregulated inflammation in PTSD and further explore how the neurobiological underpinnings of PTSD, in the context of fear learning and extinction acquisition and recall, may interact with inflammation. We then present evidence for cognitive dysfunction in PTSD, highlighting findings from human work. Potential therapeutic approaches utilizing novel pharmacological and behavioral interventions that target inflammation and cognition also are discussed.

Neuroprotective Effects of Fluoxetine Against Chronic Stress-Induced Neural Inflammation and Apoptosis: Involvement of the p38 Activity

Depression is considered a widespread neuropsychiatric disease associated with neuronal injury within specific brain regions. Fluoxetine, a selective serotonin reuptake inhibitor, has been widely used in depressed patients. Recently, fluoxetine has demonstrated neuroprotective effects apart from the effect on serotonin. However, the underlying mechanism involved in this neuroprotection remains unclear, in particular, whether fluoxetine exerts antidepressant effects via protecting against neuronal injury. Here, we found that treatment with fluoxetine (10 mg/kg, i.p.) for 2 weeks ameliorated depression-like behaviors in a chronic unpredictable mild stress (CUMS)-induced rat model of depression and was accompanied with an alleviation of glia activation and inhibition of interleukin-1β (IL-1β), interferon gamma (IFN-γ), and tumor necrosis factor-α (TNF-α) expression in the hippocampal dentate gyrus (DG) region. Meanwhile, CUMS rats treated with fluoxetine showed reductions in neuronal apoptosis and a downregulation of the apoptotic protein Bax, cleaved caspase 3, and caspase 9 levels. These effects appear to involve a downregulation of p38 mitogen-activated protein kinase (MAPK) signaling within the DG hippocampus as the specific inhibitor of p38 MAPK, SB203580, significantly suppressed apoptosis, as well as ameliorated depressive behaviors resulting from CUMS exposure. Moreover, fluoxetine could rescue neuronal deterioration and depression-like phenotypes caused by overexpression of p38 in DG. This finding extends our knowledge on the antidepressant-like effects of fluoxetine, which appear to at least partially profit from neuroprotection against inflammation and neuronal apoptosis via downregulation of the p38 MAPK pathway. The neuroprotective mechanisms of fluoxetine may provide some novel therapeutic avenues for stress-related neurological diseases.

Inflammasomes in neuroinflammatory and neurodegenerative diseases

Neuroinflammation and neurodegeneration often result from the aberrant deposition of aggregated host proteins, including amyloid‐β, α‐synuclein, and prions, that can activate inflammasomes. Inflammasomes function as intracellular sensors of both microbial pathogens and foreign as well as host‐derived danger signals. Upon activation, they induce an innate immune response by secreting the inflammatory cytokines interleukin (IL)‐1β and IL‐18, and additionally by inducing pyroptosis, a lytic cell death mode that releases additional inflammatory mediators. Microglia are the prominent innate immune cells in the brain for inflammasome activation. However, additional CNS‐resident cell types including astrocytes and neurons, as well as infiltrating myeloid cells from the periphery, express and activate inflammasomes. In this review, we will discuss current understanding of the role of inflammasomes in common degenerative diseases of the brain and highlight inflammasome‐targeted strategies that may potentially treat these diseases.

Dextran Sulphate of Sodium-induced colitis in mice: antihyperalgesic effects of ethanolic extract of Citrus reticulata and potential damage to the central nervous system

Citrus species are widely related to antihyperalgesic and anti-inflammatory effects. The aim of this study was to investigate if treatment with ethanolic extract from peels of mature Citrus reticulata Blanco causes antihyperalgesic effects on the referred mechanical hyperalgesia in a model of dextran sulphate of sodium (DSS)-induced colitis in mice, as well as the possible oxidative damage in different regions of the brain induced by its inflammatory reaction. Antihyperalgesia (30 to 300 mg/kg) was investigated by behavioral response (frequency of response to von Frey filament stimulation) in Swiss mice, while damage to central nervous system was investigated through techniques that evaluated oxidative stress using male black C57 BL6 mice (n=8). Treatment of the animals with the extract (100 mg/kg) from days 3 to 5 after colitis induction reduced referred the mechanical hyperalgesia (32.6 ± 5.1) in relation to the control group (57.4 ± 2.0). Levels of lipid peroxidation or carbonyl proteins were augmented in colitis-induced animals in relation to the disease group. These results indicated an antihyperalgesic effect of the studied extract and a potential impairment of the central nervous system functioning caused by inflammation during colitis, which could be related to mental disorders observed in patients suffering of this pathology.

Role of Interleukin-6 in Depressive Disorder

Major depressive disorder (MDD), which is a leading psychiatric illness across the world, severely affects quality of life and causes an increased incidence of suicide. Evidence from animal as well as clinical studies have indicated that increased peripheral or central cytokine interleukin-6 (IL-6) levels play an important role in stress reaction and depressive disorder, especially physical disorders comorbid with depression. Increased release of IL-6 in MDD has been found to be a factor associated with MDD prognosis and therapeutic response, and may affect a wide range of depressive symptomatology. However, study results of the IL6 genetic effects in MDD are controversial. Increased IL-6 activity may cause depression through activation of hypothalamic-pituitary-adrenal axis or influence of the neurotransmitter metabolism. The important role of neuroinflammation in MDD pathogenesis has created a new perspective that the combining of blood IL-6 and other depression-related cytokine levels may help to classify MDD biological subtypes, which may allow physicians to identify the optimal treatment for MDD patients. To modulate the IL-6 activity by IL-6-related agents, current antidepressive agents, herb medication, pre-/probiotics or non-pharmacological interventions may hold great promise for the MDD patients with inflammatory features.

The cytokine network in the pathogenesis of major depressive disorder. Close to translation?

Major depressive disorder (MDD) is a common condition that afflicts the general population across a broad spectrum of ages and social backgrounds. MDD has been identified by the World Health Organization as a leading cause of disability worldwide. Approximately 30% of patients are poor responsive to standard of care (SOC) treatment and novel therapeutic approaches are warranted. Since chronic inflammation, as it is often observed in certain cancers, type 2 diabetes, psoriasis and chronic arthritis, are accompanied by depression, it has been suggested that immunoinflammatory processes may be involved in the pathogenesis of MDD. Cytokines are a group of glycoproteins secreted from lymphoid and non-lymphoid cells that orchestrate immune responses. It has been suggested that a dysregulated production of cytokines may be implicated in the pathogenesis and maintenance of MDD. On the basis of their functions, cytokines can be subdivided in pro-inflammatory and anti-inflammatory cytokines. Since abnormal blood and cerebrospinal fluid of both pro and anti-inflammatory cytokines are altered in MDD, it has been suggested that abnormal cytokine homeostasis may be implicated in the pathogenesis of MDD and possibly to induction of therapeutic resistance. We review current data that indicate that cytokines may represent a useful tool to identify MDD patients that may benefit from tailored immunotherapeutic approaches and may represent a potential tailored therapeutic target.

Alzheimer's Disease and Neurotransmission Gene Variants: Focus on Their Effects on Psychiatric Comorbidities and Inflammatory Parameters

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder accounting for 60-70% of dementia cases. Genetic origin accounts for 49-79% of disease risk. This paper aims to investigate the association of 17 polymorphisms within 7 genes involved in neurotransmission (COMT, HTR2A, PPP3CC, RORA, SIGMAR1, SIRT1, and SORBS3) and AD.

METHODS

A Greek and an Italian sample were investigated, for a total of 156 AD subjects and 301 healthy controls. Exploratory analyses on psychosis and depression comorbidities were performed, as well as on other available clinical and serological parameters.

RESULTS

AD was associated with rs4680 within the COMT gene in the total sample. Trends of association were found in the 2 subsamples. Some nominal associations were found for the depressive phenotype. rs10997871 and rs10997875 within SIRT1 were nominally associated with depression in the total sample and in the Greek subsample. rs174696 within COMT was associated with depression comorbidity in the Italian subsample.

DISCUSSION

Our data support the role of COMT, and particularly of rs4680, in the pathogenesis of AD. Furthermore, the SIRT1 gene seems to modulate depressive symptomatology in the AD population.

Longitudinal transcriptome-wide gene expression analysis of sleep deprivation treatment shows involvement of circadian genes and immune pathways

Therapeutic sleep deprivation (SD) rapidly induces robust, transient antidepressant effects in a large proportion of major mood disorder patients suffering from a depressive episode, but underlying biological factors remain poorly understood. Research suggests that these patients may have altered circadian molecular genetic 'clocks' and that SD functions through 'resetting' dysregulated genes; additional factors may be involved, warranting further investigation. Leveraging advances in microarray technology enabling the transcriptome-wide assessment of gene expression, this study aimed to examine gene expression changes accompanying SD and recovery sleep in patients suffering from an episode of depression. Patients (N = 78) and controls (N = 15) underwent SD, with blood taken at the same time of day before SD, after one night of SD and after recovery sleep. A transcriptome-wide gene-by-gene approach was used, with a targeted look also taken at circadian genes. Furthermore, gene set enrichment, and longitudinal gene set analyses including the time point after recovery sleep, were conducted. Circadian genes were significantly affected by SD, with patterns suggesting that molecular clocks of responders and non-responders, as well as patients and controls respond differently to chronobiologic stimuli. Notably, gene set analyses revealed a strong widespread effect of SD on pathways involved in immune function and inflammatory response, such as those involved in cytokine and especially in interleukin signalling. Longitudinal gene set analyses showed that in responders these pathways were upregulated after SD; in non-responders, little response was observed. Our findings emphasize the close relationship between circadian, immune and sleep systems and their link to etiology of depression at the transcriptomic level.

Adiponectin suppresses amyloid-β oligomer (AβO)-induced inflammatory response of microglia via AdipoR1-AMPK-NF-κB signaling pathway

Background

Microglia-mediated neuroinflammation is important in Alzheimer’s disease (AD) pathogenesis. Extracellular deposition of β-amyloid (Aβ), a major pathological hallmark of AD, can induce microglia activation. Adiponectin (APN), an adipocyte-derived adipokine, exerts anti-inflammatory effects in the periphery and brain. Chronic APN deficiency leads to cognitive impairment and AD-like pathologies in aged mice. Here, we aim to study the role of APN in regulating microglia-mediated neuroinflammation in AD.

Methods

Inflammatory response of cultured microglia (BV2 cells) to AβO and effects of APN were studied by measuring levels of proinflammatory cytokines (tumor necrosis factor α [TNFα] and interleukin-1β [IL-1β]) in cultured medium before and after exposure to AβO, with and without APN pretreatment. Adiponectin receptor 1 (AdipoR1) and receptor 2 (AdipoR2) were targeted by small interference RNA. To study the neuroprotective effect of APN, cultured HT-22 hippocampal cells were treated with conditioned medium of AβO-exposed BV2 cells or were co-cultured with BV2 cells in transwells. The cytotoxicity of HT-22 hippocampal cells was assessed by MTT reduction. We generated APN-deficient AD mice (APN^−/−5xFAD) by crossing APN-knockout mice with 5xFAD mice to determine the effects of APN deficiency on microglia-mediated neuroinflammation in AD.

Results

AdipoR1 and AdipoR2 were expressed in BV2 cells and microglia of mice. Pretreatment with APN for 2 h suppressed TNFα and IL-1β release induced by AβO in BV2 cells. Additionally, APN rescued the decrease of AMPK phosphorylation and suppressed nuclear translocation of nuclear factor kappa B (NF-κB) induced by AβO. Compound C, an inhibitor of AMPK, abolished these effects of APN. Knockdown of AdipoR1, but not AdipoR2 in BV2 cells, inhibited the ability of APN to suppress proinflammatory cytokine release induced by AβO. Moreover, pretreatment with APN inhibited the cytotoxicity of HT-22 cells co-cultured with AβO-exposed BV2 cells. Lastly, APN deficiency exacerbated microglia activation in 9-month-old APN^−/−5xFAD mice associated with upregulation of TNFα and IL-1β in the cortex and hippocampus.

Conclusions

Our findings demonstrate that APN inhibits inflammatory response of microglia to AβO via AdipoR1-AMPK-NF-κB signaling, and APN deficiency aggravates microglia activation and neuroinflammation in AD mice. APN may be a novel therapeutic agent for inhibiting neuroinflammation in AD.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1492-6) contains supplementary material, which is available to authorized users.