Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway

JOURNAL/nrgr/04.03/01300535-202511000-00028/figure1/v/2024-12-20T164640Z/r/image-tiff Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells, and can thus be used as substitutes for stem cells in stem cell therapy, thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived treatments. This lays a foundation for the development of potentially potent new treatment modalities for ischemic stroke. However, the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear, presenting challenges for clinical translation. To promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside, we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic stroke. We found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal apoptosis. The human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase, mammalian target of rapamycin, and protein kinase B, and these effects were reversed by treatment with a phosphoinositide 3-kinase inhibitor. These findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway. Finally, we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety profile. Therefore, human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

Berberine: An isoquinoline alkaloid targeting the oxidative stress and gut-brain axis in the models of depression

Depression seriously affects people's quality of life, and there is an urgent need to find novel drugs to cure treatment-resistant depression. Berberine (BBR), extracted from Coptis chinensis Franch., Phellodendron bark, Berberis vulgaris, and Berberis petiolaris, could be a potential multi-target drug for depression. To summarize the effects of BBR on depression in terms of in vitro or in vivo experiments, we searched electronic databases, such as PubMed, Web of Science, Google Scholar, Wanfang Database, and China National Knowledge Infrastructure, from inception until May 2024. Then, we summarize that BBR has indirect antidepressant properties to improve depressive symptoms, manifesting in modulating the gut microbial community, strengthening the intestinal barrier, increasing the abundance of short-chain fatty acid-producing bacteria, and regulating tryptophan metabolism. BBR also exerts antidepressant-like effects via remodulating nuclear factor-erythroid 2-related factor 2/antioxidant response element pathway, hypothalamic-pituitary-adrenal axis, and peroxisome proliferators-activated receptor-delta. Nevertheless, further clinical trials and more high-quality animal studies are needed to show the actual clinical value of BBR for depression.

AA147 Alleviates Symptoms in a Mouse Model of Multiple Sclerosis by Reducing Oligodendrocyte Loss

Inflammation-induced oligodendrocyte death and CNS demyelination are key features of multiple sclerosis (MS). Inflammation-triggered endoplasmic reticulum (ER) stress and oxidative stress promote tissue damage in MS and in its preclinical animal model, experimental autoimmune encephalitis (EAE). Compound AA147 is a potent activator of the ATF6 signaling arm of the unfolded protein response (UPR) that can also induce antioxidant signaling through activation of the NRF2 pathway in neuronal cells. Previous work showed that AA147 protects multiple tissues against ischemia/reperfusion damage through ATF6 and/or NRF2 activation; however, its therapeutic potential in neuroinflammatory disorders remains unexplored. Here, we demonstrate that AA147 ameliorated the clinical symptoms of EAE and reduced ER stress, oligodendrocyte loss, and demyelination. Additionally, AA147 suppressed T cells in the CNS without altering the peripheral immune response. Importantly, AA147 significantly increased the expressions of Grp78, an ATF6 target gene, in oligodendrocytes, while enhancing levels of Grp78 as well as Ho-1, an NRF2 target gene, in microglia. In cultured oligodendrocytes, AA147 promoted nuclear translocation of ATF6, but not NRF2. Intriguingly, AA147 altered the microglia activation profile, possibly by triggering the NRF2 pathway. AA147 was not therapeutically beneficial during the acute EAE stage in mice lacking ATF6 in oligodendrocytes, indicating that protection primarily involves ATF6 activation in these cells. Overall, our results suggest AA147 as a potential therapeutic opportunity for MS by promoting oligodendrocyte survival and regulating microglia status through distinct mechanisms.

Prenatal immune origins of brain aging differ by sex

With an increasing aging population and Alzheimer's disease tsunami, it is critical to identify early antecedents of brain aging to target for intervention and prevention. Women and men develop and age differently, thus using a sex differences lens can contribute to identification of early risk biomarkers and resilience. There is growing evidence for fetal antecedents to adult memory impairments, potentially through disruption of maternal prenatal immune pathways. Here, we hypothesized that in utero exposure to maternal pro-inflammatory cytokines will have sex-dependent effects on specific brain circuitry regulating offspring's memory and immune function that will be retained across the lifespan. Using a unique prenatal cohort, we tested this in 204 adult offspring, equally divided by sex, who were exposed/unexposed to an adverse in utero maternal immune environment and followed into early midlife (~age 50). Functional magnetic resonance imaging results showed exposure to pro-inflammatory cytokines in utero (i.e., higher maternal IL-6 and TNF-α levels) was significantly associated with sex differences in brain activity and connectivity underlying memory circuitry and performance and with a hyperimmune state, 50 years later. In contrast, the anti-inflammatory cytokine, IL-10 alone, was not significantly associated with memory circuitry in midlife. Predictive validity of prenatal exposure was underscored by significant associations with age 7 academic achievement, also associated with age 50 memory performance. Results uniquely demonstrated that adverse levels of maternal in utero pro-inflammatory cytokines during a critical period of the sexual differentiation of the brain produced long-lasting effects on immune function and memory circuitry/function from childhood to midlife that were sex-dependent, brain region-specific, and, within women, reproductive stage-dependent.

[1H-13C]-NMR-Based Metabolic Kinetics Reveals Brain Neurochemical Alterations in Mice After Retinal Ischemia-Reperfusion Injury

Retinal ischemia-reperfusion injury (RIRI) is a pathological process that occurs in various blinding eye diseases and is often accompanied by anxiety and depression. However, the underlying metabolic mechanism of mood disorders remains unclear. This study aimed to investigate the metabolic dynamics of the brain after RIRI. C57BL/6 J mice were used to establish the RIRI model and assessed after 1 and 7 days. Mood-related behaviors were examined using open-field, elevated plus-maze, and forced swimming tests. Retinal injury histology was assessed using retinal hematoxylin and eosin staining. Retinal apoptosis was measured via the TdT-mediated dUTP nick-end labeling staining. The 13C-labeled metabolite information for six brain regions of interest was obtained using the [1H-13C]-NMR technique. Retinal tissue damage and cell apoptosis in the retina were observed 1 and 7 days after RIRI. One day after RIRI, mice displayed anxiety- and depression-like behaviors, and multiple metabolites involved in the glutamine (Gln)/glutamate (Glu)-γ-aminobutyric acid (GABA) and tricarboxylic acid (TCA) cycles exhibited reductions in all studied brain regions, with frontal cortex (FC) and temporal cortex (TC) being the most markedly altered. Metabolites and behavioral indicators nearly returned to normal after 7 days. Significant positive correlations between Gln/Glu-GABA and TCA cycle metabolites were observed in the RIRI brain. The results revealed that within a short period after RIRI, there was a reduction in brain metabolites and a disruption of the Gln/Glu-GABA and TCA cycles, which may contribute to mood disorders in mice.

Ayahuasca Pretreatment Prevents Sepsis-Induced Anxiety-Like Behavior, Neuroinflammation, and Oxidative Stress, and Increases Brain-Derived Neurotrophic Factor

The psychoactive decoction Ayahuasca (AYA) used for therapeutic and religious purposes by indigenous groups and peoples from Amazonian regions produces anti-inflammatory and neuroprotective effects. Thus, it may be useful to attenuate the neuroinflammation and related anxiety- and depressive-like symptoms elicited by inflammatory insults such as sepsis. Rats were pretreated for 3 days with different doses of AYA. Twenty-four hours after, cecal ligation and puncture (CLP) was performed. On days 1-4, post-CLP behavioral tests to assess anxiety-like behavior were performed. After 24-h, neuroinflammation, oxidative stress, myeloperoxidase activity, and mitochondrial metabolism were assessed in the prefrontal cortex (PFC), hippocampus (HP), and cortex. AYA pretreatment increased the time spent in the open arms of the elevated plus maze and prevented the sepsis-induced hyper-grooming and -rearing behavior, suggesting an anxiolytic effect. AYA pretreatment increased the levels of the anti-inflammatory interleukin 4, in the PFC and the cortex, and brain-derived neurotrophic factor in the cortex. Moreover, AYA pretreatment increased myeloperoxidase activity in the PFC and the HP and decreased nitrite/nitrate concentration in the PFC, HP, and cortex of septic rats, suggesting enhanced neutrophil activation and decreased nitric oxide signaling. Furthermore, AYA pretreatment prevented lipid peroxidation in the PFC, HP, and cortex of septic rats as measured by decreased levels of thiobarbituric acid reactive substances. Levels of protein carbonyls and activity of superoxide dismutase, citrate synthase, succinate dehydrogenase, and mitochondrial respiratory chain were not affected. Together, AYA represents a promising approach to prevent sepsis-induced neuroinflammatory and oxidative stress and associated anxiety-like symptoms.

Salvianolic acid B (SalB) improves high-fat diet (HFD)-caused cognitive impairment in mice by modulating the Trem2/Dap12 pathway in vivo and in vitro

Salvianolic acid B (SalB), which extracted from Salvia miltiorrhiza Bunge (Labiatae), is a traditional Chinese medicine. SalB is widely used in nervous system diseases. This study evaluated the protective effect of SalB on high-fat diet (HFD)-induced cognitive impairment and its mechanisms in vivo and in vitro. The behavior tests demonstrated that SalB alleviated motor skills and learning capacity in HFD mice. Animal experiments have confirmed that SalB reduced the mRNA expression of inflammatory markers and the Trem2/Dap12 pathway in HIP. Furthermore, SalB inhibited the microglia Trem2/Dap12 pathway in HIP. In vivo, palmitic acid (PA) was used to intervene in BV2 cells to construct an inflammatory. SalB reduced the mRNA expression of inflammatory markers and inhibited the Trem2/Dap12 pathway in BV2 cells. In conclusion, SalB treatment may serve as a possible therapy for cognitive impairment induced by HFD.

The possible role of neurogenesis activators in temporal lobe epilepsy: State of art and future perspective

Neurogenesis is a complex process by which the neurons and supporting cells of the central nervous system (CNS) are generated by neural stem cells. Adult hippocampal neurogenesis (AHN) in the human brain is an active process during life and plays a critical role in the regulation of memory, cognition, and mood. It has been shown that epilepsy is linked with dysregulation of AHN. Of note, AHN is very sensitive to the pathological electrical stimuli during epileptic seizures, which result in the induction of neurogenesis in acute epilepsy and inhibition of neurogenesis in chronic epilepsy. Epileptic seizure-induced neurodegeneration activates the mobilization of neural stem cells during neurogenesis to substitute for neural loss in temporal lobe epilepsy (TLE), which is the most refractory type of epilepsy. Moreover, recurrent epileptic seizures in TLE trigger neurogenesis in certain brain regions. However, AHN is a transient acute epileptic seizure that terminated with 1-4 weeks following status epilepticus (SE). Nevertheless, adult AHN is dramatically reduced in chronic epilepsy and associated with the development of cognitive impairment in TLE. These findings indicate that impairment of AHN is linked with the severity of epileptic seizures. Hence, neurogenesis activators may attenuate the pathogenesis of TLE. Therefore, this review aims to discuss and explain the beneficial role of AHN in TLE and how neurogenesis activators could be effective in the management of epilepsy.

Gastrodin enhances stress resilience through promoting Wnt/β-Catenin-dependent neurogenesis

BACKGROUND

Enhancing stress resilience constitutes a pivotal strategy in mitigating the risk of depression, making it a critical component of both prevention and treatment. In the current work, we identified a compound, gastrodin (GAS), as capable of enhancing stress resilience, as demonstrated by its ability to protect against depression following chronic stress exposure.

OBJECTIVES

To elucidate the potential of GAS to promote neurogenesis under chronic stress, along with the associated cellular and molecular processes involved.

METHOD

We evaluated the effect of GAS on NSPC proliferation and differentiation using both in vitro and in vivo investigations. Neurogenesis was inhibited using temozolomide to verify GAS's impact on stress resilience. Comprehensive methodologies, including hippocampal transcriptome analysis and western blotting, were utilized to identify the involvement of the Wnt/β-catenin pathway. Immunolocalization was conducted to confirm β-catenin's nuclear translocation in SOX2+ cells within the hippocampal dentate gyrus subgranular zone.

RESULTS

GAS demonstrated robust stimulation of NSPC proliferation and neuronal differentiation, enhancing adult hippocampal neurogenesis under conditions of chronic stress. Inhibition of neurogenesis negated GAS's protective effects on stress resilience. Integrated analysis pointed to the Wnt/β-catenin signaling pathway within NSPCs as a crucial mechanism facilitating GAS-promoted neurogenesis. Inhibiting Wnt expression or blocking β-catenin's nuclear translocation abolished GAS's neurogenic and stress-resilience enhancing effects.

CONCLUSION

These results suggested that GAS directly activates the Wnt/β-catenin signaling pathway, which promotes the proliferation and neuronal differentiation of NSPCs, thereby enhancing adult hippocampal neurogenesis and promoting stress resilience to mitigate the risk of depression.

Stimulation of microglia leads to a rapid antidepressant effect by triggering astrocytic P2Y1Rs and promoting BDNF-mediated neurogenesis in the hippocampus

Reversing the decline of microglia in the dentate gyrus of stressed animals has antidepressant effects, but the molecular mechanisms are unclear. Since microglia normally interact with astrocytes and astrocytic purinergic 2Y1 receptor (P2Y1R) signaling plays an important role in regulating cellular crosstalk, we hypothesize that astrocytic P2Y1R signaling may mediate the antidepressant effects of microglia stimulation. Our results showed that a single injection of low-dose lipopolysaccharide (LPS) (100 μg/kg) elicited rapid antidepressant effects and a significant increase in adenosine triphosphate (ATP) levels in the dentate gyrus in chronically stressed mice, and that these effects of LPS were abolished by chemogenetic inhibition of microglia. Depletion of endogenous ATP, non-specific antagonization of purinergic receptors, or specific inhibition of P2Y1Rs, but not other purinergic receptors, by MRS2179 in the hippocampus abolished the antidepressant effects of low-dose LPS. Conditional gene knockout data showed that the antidepressant effect of low-dose LPS could not be observed in mice lacking P2Y1Rs in astrocytes but not in forebrain neurons. Chemogenetic inhibition of microglia in the dentate gyrus, specific deletion of P2Y1Rs in astrocytes and the absence of ATP abolished the increase in doublecortin (DCX)+ cells and brain-derived neurotrophic factor (BDNF) induced by a low dose of LPS in the dentate gyrus of stressed mice, and infusion of BDNF antibodies into the hippocampus simultaneously abolished the pro-neurogenesis and antidepressant effects of microglia stimulation in stressed mice. Taken together, these results suggest that ATP signaling mobilized by microglia stimulation has an antidepressant effect by triggering astrocytic P2Y1R-dependent synthesis of BDNF.

Ginsenoside CK modulates glucose metabolism via PPARγ to ameliorate SCOP-induced cognitive dysfunction

Ginsenoside compound K (CK) exhibits neuroprotective properties; however, the underlying mechanisms behind these effects have not been investigated thoroughly. CK is the primary active compound derived from ginseng and is metabolized in the gut. It enhances neuronal function by modulating the gut microflora. Therefore, the present study aimed to elucidate the mechanism through which CK enhances cognitive function, employing gut microbiome and microarray analyses. The results revealed that CK upregulated the expression of peroxisome proliferator-activated receptor gamma (PPARγ), suppressed amyloid-β (Aβ) aggregation in hippocampal neurons, and influenced the expression of cyclin-dependent kinase-5 (CDK5), (including insulin receptor substrate 2) IRS2, insulin-degrading enzyme (IDE), glycogen synthase kinase-3 beta (GSK-3β), glucose transporter type 1 (GLUT1), and glucose transporter type 3 (GLUT3) proteins. These proteins play crucial roles in regulating brain glucose metabolism, increasing neuronal energy, and reducing neuronal apoptosis, thereby ameliorating cognitive impairment in mice.

Kynurenic Acid and Promotion of Activity-Dependent Synapse Elimination in Schizophrenia

OBJECTIVE

Schizophrenia is a neurodevelopmental disorder characterized by an excessive loss of synapses. Kynurenic acid (KYNA), a neuroactive metabolite of tryptophan along the kynurenine pathway, can induce schizophrenia-related phenotypes in rodents, and clinical studies have revealed elevated KYNA levels in the CNS of individuals with schizophrenia. However, the factors that cause elevated KYNA levels in schizophrenia, and the mechanisms by which KYNA contributes to pathophysiology, remain largely elusive. The authors used patient-derived cellular modeling to test the hypothesis that KYNA can induce microglia-mediated synapse engulfment by reducing neuronal activity.

METHODS

Patient-derived induced pluripotent stem cells were used to generate 2D cultures of neurons and microglia-like cells, as well as forebrain organoids with innately developing microglia, to study how KYNA influences synaptic activity and microglial uptake of synaptic structures. To verify the experimental data in a clinical context, large-scale developmental postmortem brain tissue and genetic datasets were used to study coexpression networks for the KYNA-producing kynurenine aminotransferases (KATs) regarding enrichment for common schizophrenia genetic risk variants and functional annotations.

RESULTS

In these patient-derived experimental models, KYNA induced uptake of synaptic structures in microglia, and inhibition of the endogenous KYNA production led to a decrease in the internalization of synapses in microglia. The integrated large-scale transcriptomic and genetic datasets showed that KYNA-producing KATs enriched for genes governing synaptic activity and genetic risk variants for schizophrenia.

CONCLUSIONS

Together, these results link genetic risk variants for schizophrenia to elevated production of KYNA and excessive and activity-dependent internalization of synaptic material in microglia, while implicating pharmacological inhibition of KATs as a strategy to avoid synapse loss in schizophrenia.

Microglia Sing the Prelude of Neuroinflammation-Associated Depression

Major depressive disorder (MDD) is a psychiatric condition characterized by sadness and anhedonia and is closely linked to chronic low-grade neuroinflammation, which is primarily induced by microglia. Nonetheless, the mechanisms by which microglia elicit depressive symptoms remain uncertain. This review focuses on the mechanism linking microglia and depression encompassing the breakdown of the blood-brain barrier, the hypothalamic-pituitary-adrenal axis, the gut-brain axis, the vagus and sympathetic nervous systems, and the susceptibility influenced by epigenetic modifications on microglia. These pathways may lead to the alterations of microglia in cytokine levels, as well as increased oxidative stress. Simultaneously, many antidepressant treatments can alter the immune phenotype of microglia, while anti-inflammatory treatments can also have antidepressant effects. This framework linking microglia, neuroinflammation, and depression could serve as a reference for targeting microglia to treat depression.

Patchouli alcohol from Pogostemon cablin Benth inhibits H1N1 infection by repressing inflammasome and proptosis by targeting ubiquitin specific peptidase 18

Influenza virus infection can cause lung inflammation and viral pneumonia in patients. Patchouli alcohol (PA), a tricyclic sesquiterpene derived from Pogostemonis Herba, has been shown to alleviate inflammation in various diseases. However, the molecular mechanism by which patchouli exerts its anti-inflammatory effects, particularly its role in mitigating influenza virus induced inflammation and pneumonia during H1N1 viral infection, remains largely unclear. Herein, we found that PA considerably reduced body weight loss, lung pathological index and attenuated lung histological damage in H1N1-infected mice. Mechanistically, PA reduced the production and secretion of inflammatory cytokines via inhibition of the NF-κB-signaling pathway and blocking inflammasome-mediated proptosis. Additionally, proteomic analysis identified several potential targets of PA, with ubiquitin-specific peptidase 18 (USP18) emerging as a key candidate. Further investigation revealed that PA binds to USP18, enhancing its stability and increasing its transcriptional and translational expression. Overall, our results emphasize the anti-inflammatory effects of PA during influenza virus infection. PA may alleviate lung inflammation and damage by targeting USP18, offering a potential therapeutic strategy for treating influenza-induced lung complications.

Minocycline treatment attenuates neurobehavioural abnormalities and neurostructural aberrations in the medial prefrontal cortex in mice fed a high-fat diet during adolescence

A preference for and overconsumption of a high-fat diet (HFD) are common among adolescents and are recognized as risk factors for multiple mental disorders. The protracted maturation of the medial prefrontal cortex (mPFC), a key brain structure that plays a critical role in mental functions that are essential for both developing and mature individuals (including emotional processing, decision making, risk assessment, and creative thinking), during adolescence renders it more vulnerable to the environmental insults experienced during this critical developmental window. However, the effects of HFD consumption during adolescence on mPFC-related behaviours and the underlying mechanisms need to be further investigated. In this study, we observed that mice fed a HFD throughout adolescence developed depressive- and anxiety-like behaviours and distinctively increased risk-avoidance behaviour, accompanied by morphological aberrations of both pyramidal neuron and microglia in the mPFC. The systemic administration of minocycline, a well-known broad-spectrum antibiotic, effectively attenuated the adverse effects of HFD consumption during adolescence on neurobehaviours and the morphology of pyramidal neurons in the mPFC. This study provides new insights into the psychological effects of long-term HFD consumption during adolescence and indicates the existence of a window during which microglial stabilization may be a promising strategy to protect against the HFD consumption-induced increase in the risk of psychiatric disorders.

The association between maternal sleep and circadian rhythms during pregnancy and infant sleep and socioemotional outcomes

Studies have established that maternal sleep and circadian rhythm disturbances during pregnancy are associated with poor prenatal and perinatal outcomes for mothers and offspring. However, little work has explored its effects on infant sleep or socioemotional outcomes. The current study examined the relationship between maternal sleep and circadian rhythm disturbances during pregnancy and infant sleep and socioemotional outcomes in a diverse sample of N = 193 mothers and their infants (51% White; 52% Female; Mage = 11.95 months). Maternal sleep and circadian rhythms during pregnancy were assessed using self-reports and actigraphy. Mothers reported on infants' sleep and socioemotional outcomes when infants were one year old. When controlling for infant sex, age, gestational age at birth, family income-to-needs ratios, and maternal depression, mothers who reported more sleep problems during pregnancy had infants with more sleep disturbances when they were one year old. Moreover, mothers who had later sleep timing (i.e., went to bed and woke up later, measured via actigraphy) during pregnancy had infants with more dysregulation (e.g., increased feeding difficulties, sensory sensitivities) and externalizing problems, and mothers with increased intra-daily variability in rest-activity rhythms (as measured via actigraphy) had infants with more externalizing problems. Findings suggest that maternal sleep and circadian rhythm disturbances during pregnancy may be a risk factor for infant sleep problems and socioemotional difficulties.

GPR120 internalization: a key mechanism for EPA in antidepressant action

The incidence of depression is on the rise, and currently available antidepressants often exhibit limited efficacy in many patients. Additionally, the underlying mechanisms of depression remain poorly understood. Research has shown that neuroinflammation, driven by M1 microglial phenotypic polarization, contributes to neuronal abnormalities implicated in the development of depression. Eicosapentaenoic acid (EPA) has emerged as a promising therapeutic agent for depression. However, the specific target of EPA's anti-stress effects is yet to be identified. This study aimed to explore the pathogenesis of depression and elucidate the central regulatory mechanisms underlying EPA's antidepressant efficacy. In this study, mice were orally administered EPA for five consecutive weeks. During this period, they were subjected to daily chronic unpredictable mild stress (CUMS) and treated with lipopolysaccharide (LPS, 0.5 mg kg-1, intraperitoneally) every other week. The results demonstrated that EPA significantly alleviated neuronal degeneration in the medial prefrontal cortex. Furthermore, EPA improved synaptic plasticity impairments induced by CUMS combined with LPSs, as indicated by the increased protein levels of Nlgn1, PSD95, GAP43, and Syn. EPA also reduced neuroinflammation by inhibiting M1 microglial polarization and NLRP3 inflammasome activation. Notably, EPA exerted antidepressant-like effects by modulating GPR120. These findings suggest that EPA intake can mitigate abnormal mood and behavior induced by elevated immune-inflammatory signals. These findings suggest that EPA intake can attenuate abnormal moods and behaviors induced by elevated immune-inflammatory signals. Therefore, EPA may be a promising strategy for the clinical treatment of inflammatory depression.

Microglia efferocytosis: an emerging mechanism for the resolution of neuroinflammation in Alzheimer's disease

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by significant neuroinflammatory responses. Microglia, the immune cells of the central nervous system, play a crucial role in the pathophysiology of AD. Recent studies have indicated that microglial efferocytosis is an important mechanism for clearing apoptotic cells and cellular debris, facilitating the resolution of neuroinflammation. This review summarizes the biological characteristics of microglia and the mechanisms underlying microglial efferocytosis, including the factors and signaling pathways that regulate efferocytosis, the interactions between microglia and other cells that influence this process, and the role of neuroinflammation in AD. Furthermore, we explore the role of microglial efferocytosis in AD from three perspectives: its impact on the clearance of amyloid plaques, its regulation of neuroinflammation, and its effects on neuroprotection. Finally, we summarize the current research status on enhancing microglial efferocytosis to alleviate neuroinflammation and improve AD, as well as the future challenges of this approach as a therapeutic strategy for AD.

Potential roles for microglia in drug addiction: Adolescent neurodevelopment and beyond

Adolescence is a sensitive period for development of addiction-relevant brain circuits, and it is also when people typically start experimenting with drugs. Unfortunately, such substance use may cause lasting impacts on the brain, and might increase vulnerability to later-life addictions. Microglia are the brain's immune cells, but their roles in shaping neural connectivity and synaptic plasticity, especially in developmental sensitive periods like adolescence, may also contribute to addiction-related phenomena. Here, we overview how drugs of abuse impact microglia, and propose that they may play poorly-understood, but important roles in addiction vulnerability and progression.

HMGB1: Different secretion pathways with pivotal role in epilepsy and major depressive disorder

High-mobility group box 1 (HMGB1) protein is a highly prevalent protein that, once it is translocated to an extracellular site, can contribute to the pathogenesis of autoimmune and inflammatory responses, including epilepsy and depression. The conditions needed for release are associated with the production of multiple isoforms, and this translocation may occur in response to both immune cell activation and cell death. HMGB1 has been shown to interact with different mediators, including exportin 1, notch receptors, mitogen-activated protein kinase, STAT, tumor protein 53, and inflammasomes. Furthermore, as a crucial inflammatory mediator, HMGB1 has demonstrated upregulated expression and a higher percentage of translocation from the nucleus to the cytoplasm, acting on downstream receptors such as toll-like receptor 4 and receptor for advanced glycation end products, thereby activating interleukin-1 beta and nuclear factor kappa-B, intensifying inflammatory responses. In this review, we aim to discuss the different molecular interactions for the secretion of HMGB1 along with its pivotal role in epilepsy and major depressive disorder.

MgSO4 alleviates hippocampal neuroinflammation and BBB damage to resist CMS-induced depression

Purpose

Magnesium sulfate (MgSO4) possesses the advantages of being readily accessible, cost-effective, and having low toxicity. It has potential applications as a neuroprotective agent. The mechanisms underlying the effects of Mg2+ treatment on depression and its neuroprotective properties remain poorly elucidated.

Methods

In this study, we employed chronic mild unpredictable stress (CMS)-induced mice were orally administered with MgSO4 or pioglitazone. The CMS-induced depressive-like behaviors of mice were monitored. After sacrifice, the levels of Mg2+ and inflammatory cytokines were observed. Blood-brain barrier (BBB) permeability and the M1-to-M2 shift of microglia in mouse hippocampus were detected. The expression of proteins in IKK/NF-κB and NLRP3 inflammasome signal pathway were analyzed.

Results

We found that CMS induced depressive-like behaviors as well as hypomagnesemia in mice, which were accompanied with hypersecretion of inflammatory cytokines in hippocampus of mice. These animals induced by CMS exhibited hippocampal neuroinflammation characterized by an elevated number of Iba+ microglia with enlarged cell bodies and increased branching structures. In CMS-induced mice, MgSO4 alleviated CMS-induced depressive-like behaviors and hypomagnesemia, reduced the levels of inflammatory cytokines in both serum and hippocampus, decreased the number of Iba+ microglia, modulated microglia polarization and repaired the BBB damage. MgSO4 also significantly facilitates the M1-to-M2 shift in CMS-induced mouse hippocampus and lipopolysaccharide (LPS)-induced BV2 microglia. Mechanically, we found that MgSO4 inhibited microglia activation and BBB damage, possibly by suppressing IKK/NF-κB and NLRP3 inflammasome signaling pathways.

Conclusion

Our findings showed that MgSO4 supplementation played an active role in the prevention and treatment of depression.

Environmental Enrichment Exposure Alleviates Geriatric Depressive-Like Symptoms through Regulating Neurogenesis and Neuroinflammation

Environmental enrichment (EE) is a significant approach to influencing brain function by altering the environment and changing living conditions and has been shown to modulate mood-related diseases, including depression. Among the elderly, depression is particularly prevalent and is often linked to social isolation. However, the specific role of EE in social isolation-related geriatric depression remains imprecise. This study was intended to explore the status of EE exposure in geriatric depression and to uncover its underlying mechanisms. We utilized 19-month-old male C57BL/6J mice, which are equivalent to humans aged 50-60 years, and induced depression through social isolation. After 2 weeks of social isolation, mice were identified as depressive by using the sugar preference test and then classified into either standard or enrichment environment groups for 4 weeks. Subsequently, conventional indices associated with depression, including neurogenesis, neurotrophic factors, and neuroinflammation, were measured. Results display that EE alleviated the depressive-like symptoms in elderly mice and enriched their social activities. Concurrently, EE regulated levels of certain neurotransmitters in the hippocampus, including the systems of glutamate, tyrosine, and histamine. Moreover, the ability of neurogenesis also increased in the hippocampus of EE mice. At the neuroinflammation level, the activation of Natural Killer (NK) cells and ARG1+ microglia is considered a major contributor to mediating the effects of EE-regulated geriatric depression. Collectively, these results underline the importance of EE in the treatment of geriatric depression and partially elucidate its underlying mechanism, offering valuable suggestions for treating social isolation--related depression via environmental modulation.

Foods for Sleep Improvement: A Review of the Potential and Mechanisms Involved

Insomnia affects one-third of the world's population; the negative effects of insomnia are significant, and traditional insomnia medications have numerous side effects and cause considerable suffering. This has aroused interest in obtaining sleep-improving substances from foods. This study conducted a comprehensive literature review using Web of Science and PubMed with keywords like "sleep", "insomnia", and "food". A subsequent summary of the literature revealed that certain foods, including milk, Ziziphus jujuba, Lactuca sativa, ginseng, Schisandra chinensis, and Juglans regia, etc., are purported to enhance sleep quality by prolonging sleep duration, reducing sleep latency, and alleviating anxiety. The mechanisms of these foods' effects mainly occur via the central nervous system, particularly the gamma-aminobutyric acid (GABA)ergic and 5-hydroxytryptamine (5-HT)ergic systems. Although this review supports the fact that they have potential, further research is needed. There are also issues such as more limited foods, fewer mechanisms, fewer pharmacokinetic studies, and more traditional research models being involved. These need to be addressed in the future to adequately address the problem of insomnia. It is hoped that this study will contribute to research into foods with sleep-improving properties and, in the future, provide an effective natural alternative for those seeking medication.

Gastrodin prevents stress-induced synaptic plasticity impairment and behavioral dysfunction via cAMP/PKA/CREB signaling pathway

BACKGROUND

Chronic stress is widely recognized as a critical factor that impairs synaptic plasticity dependent brain function and behavior, contributing to the onset of depression and anxiety disorders, which subsequently undermine learning and memory processes. Gastrodin (GAS), a prominent bioactive constituent of Gastrodiae Rhizoma exhibiting notable neuroprotective properties, holds significant potential for the prevention and treatment of stress-induced neurological dysfunction. However, the protective effects of GAS on stress-induced synaptic plasticity impairment and the underlying mechanisms have yet to be fully elucidated.

OBJECTIVES

To investigate the potential of GAS in protecting synaptic plasticity from chronic stress and its underlying cellular and molecular mechanisms.

METHOD

A chronic stress model was constructed in C57BL/6J mice, and the effects of GAS on synaptic plasticity were examined using Golgi staining and immunohistochemistry. Systematic behavioral analysis was employed to assess the impact of GAS on depressive- and anxiety-like behaviors and cognitive function of mice. Metabolomics, transcriptomics, Western blotting, immunolocalization, enzyme-linked immunosorbent assay, and the administration of signal blockers were utilized to investigate the cellular and molecular pathways via which GAS safeguards synaptic plasticity.

RESULTS

The results showed that chronic stress exposure reduces the dendritic arbor complexity, density of dendritic spines, proportion of mushroom spines of hippocampal neurons, as well as disrupts synaptic function, impairs cognitive function and induces depressive-like behaviors. Importantly, impairment of hippocampal synaptic plasticity, anxiety- and depressive-like behaviors, and cognitive decline induced by chronic stress were significantly ameliorated following GAS treatment. Moreover, we identified the cAMP/PKA/CREB signaling in hippocampal neurons as a potential mechanism through which GAS prevents synaptic plasticity impairment from chronic stress exposure. Blockade of cAMP/PKA/CREB signaling abolished the protective effects of GAS on synaptic plasticity of hippocampal neurons and behaviors in stress-exposed mice.

CONCLUSION

This study is the first to identify GAS as a potential natural compound for alleviating stress-induced synaptic plasticity impairment and behavioral dysfunction by activating the cAMP/PKA/CREB signaling pathway in hippocampal neurons, offering a promising strategy for stress-induced neurological disorders.

Unlocking the therapeutic potential of tumor-derived EVs in ischemia-reperfusion: a breakthrough perspective from glioma and stroke

Clinical studies have revealed a bidirectional relationship between glioma and ischemic stroke, with evidence of spatial overlap between the two conditions. This connection arises from significant similarities in their pathological processes, including the regulation of cellular metabolism, inflammation, coagulation, hypoxia, angiogenesis, and neural repair, all of which involve common biological factors. A significant shared feature of both diseases is the crucial role of extracellular vesicles (EVs) in mediating intercellular communication. Extracellular vesicles, with their characteristic bilayer structure, encapsulate proteins, lipids, and nucleic acids, shielding them from enzymatic degradation by ribonucleases, deoxyribonucleases, and proteases. This structural protection facilitates long-distance intercellular communication in multicellular organisms. In gliomas, EVs are pivotal in intracranial signaling and shaping the tumor microenvironment. Importantly, the cargos carried by glioma-derived EVs closely align with the biological factors involved in ischemic stroke, underscoring the substantial impact of glioma on stroke pathology, particularly through the crucial roles of EVs as key mediators in this interaction. This review explores the pathological interplay between glioma and ischemic stroke, addressing clinical manifestations and pathophysiological processes across the stages of hypoxia, stroke onset, progression, and recovery, with a particular focus on the crucial role of EVs and their cargos in these interactions.

Crosstalk between neuroinflammation and ferroptosis: Implications for Parkinson's disease progression

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the degeneration of dopaminergic neurons and the aggregation of α-synuclein. Neuroinflammation is triggered by the activation of microglia and astrocytes, which release pro-inflammatory factors that exacerbate neuronal damage. This inflammatory state also disrupts iron homeostasis, leading to the occurrence of ferroptosis. Ferroptosis is characterized by lipid peroxidation of cell membranes and iron overload. Abnormal accumulation of iron in the brain increases oxidative stress and lipid peroxidation, further aggravating neuroinflammation and damage to dopaminergic neurons. Natural products have garnered attention for their antioxidant, anti-inflammatory, and neuroprotective properties, with many plant extracts showing promising therapeutic potential in PD research. This study further investigates the potential therapeutic roles of various natural products in regulating neuroinflammation and ferroptosis. The results suggest that natural products have significant therapeutic potential in modulating the interaction between neuroinflammation and ferroptosis, making them potential treatments for PD. Future research should further validate the safety and efficacy of these natural compounds in clinical applications to develop novel therapeutic strategies for PD.

Supplementation with Lentil (Lens culinaris) Hull Soluble Dietary Fiber Ameliorates Sodium Dextran Sulfate-Induced Colitis and Behavioral Deficits via the Gut-Brain Axis

In this study, the impact of lentil hull soluble dietary fibers (SDFs) on colitis and behavioral deficits in mice was assessed. Structural characterizations of SDFs confirmed that cellulase-modified soluble dietary fiber exhibited better physicochemical properties: more porous microstructure; similar polysaccharide structure; more stable particle size distribution; higher crystallinity; better adsorption capacity; and lower viscosity. Additionally, we explored its potential cognitive benefits via the gut-brain axis by behavioral tests, histopathology, 16S rRNA sequencing, gas chromatography and metabolomics analysis. The results showed that SDFs significantly improved inflammatory symptoms in colon and brain and cognitive behaviors. LSDF had better efficacy than HSDF. LSDF intervention decreased the harmful bacteria abundance (Bacteroides, Flexispira and Escherichia, etc.) and increased beneficial bacteria abundance (Aggregatibacter and Helicobacter, etc.). LSDF also affected brain metabolites through the sphingolipid metabolism. Spearman correlation analysis showed that there was a positive correlation between harmful bacteria with inflammatory factors (LPS, IL-1β, IL-6, and TNF-α, etc.) and sphingolipid metabolites, while beneficial bacteria were positively correlated with brain-derived neurotrophic factor (BDNF), IL-10, and cognitive behavior. This study highlights the value of SDFs in future diet-based therapeutic strategies targeting gut-brain interactions.

Disturbing sleep in female adolescent mice does not increase vulnerability to depression triggers later in life

Poor sleep quality is a major issue for many adolescents and is associated with fatigue, poor academic performance, and depression. Adolescence is a crucial neurodevelopmental stage where multiple neuropsychiatric illnesses often emerge, suggesting increased central nervous system vulnerability, specifically at this age, which could be exacerbated by poor sleep. Studies on adolescent mice show that sleep deprivation or sleep disturbance (SD) induces structural and functional brain changes, indicating that SD affects the adolescent brain. The long-term consequences of such changes are poorly understood. We hypothesize that SD during adolescence increases vulnerability to future depression triggers in adulthood, such as social isolation or inflammation. To test this, female adolescent mice (post-natal day (P)36) were subjected to SD for seven days, 4 h per day during the light phase (zeitgeber time 2-6). We demonstrate that this SD protocol acutely leads to changes in the expression of Cx3Cr1, and Dnmt3b in the hippocampus and of Htr1a in the prefrontal cortex. To examine the long-term consequences of the SD protocol during adulthood (P77-84), the mice were then either exposed to single housing or received a single injection of lipopolysaccharide (LPS) to mimic known triggers of depression. Behavioral changes were examined using digital ventilated cages to track home-cage activity and the open field and tail suspension tests to assess anxiety- and despair-like behavior, respectively. In contrast to our hypothesis, we did not observe any changes in home-cage activity, anxiety- or despair-like behavior as a result of combining SD in adolescent female mice with a depression trigger in adulthood. We conclude that the adolescent brain is sensitive to SD, but SD during adolescence in mice does not lead to an exacerbated depression-like response to social isolation or inflammation during adulthood.

Luteolin ameliorates chronic stress-induced depressive-like behaviors in mice by promoting the Arginase-1+ microglial phenotype via a PPARγ-dependent mechanism

Accumulating evidence shows that neuroinflammation substantially contributes to the pathology of depression, a severe psychiatric disease with an increasing prevalence worldwide. Although modulating microglial phenotypes is recognized as a promising therapeutic strategy, effective treatments are still lacking. Previous studies have shown that luteolin (LUT) has anti-inflammatory effects and confers benefits on chronic stress-induced depression. In this study, we investigated the molecular mechanisms by which LUT regulates the functional phenotypes of microglia in mice with depressive-like behaviors. Mice were exposed to chronic restraint stress (CRS) for 7 weeks, and were administered LUT (10, 30, 40 mg· kg-1 ·day-1, i.g.) in the last 4 weeks. We showed that LUT administration significantly ameliorated depressive-like behaviors and decreased hippocampal inflammation. LUT administration induced pro-inflammatory microglia to undergo anti-inflammatory arginase (Arg)-1+ phenotypic polarization, which was associated with its antidepressant effects. Furthermore, we showed that LUT concentration-dependently increased the expression of PPARγ in LPS + ATP-treated microglia and the hippocampus of CRS-exposed mice, promoting the subsequent inhibition of the NLRP3 inflammasome. Molecular dynamics (MD) simulation and microscale thermophoresis (MST) analysis confirmed a direct interaction between LUT and peroxisome proliferator-activated receptor gamma (PPARγ). By using the PPARγ antagonist GW9662, we demonstrated that LUT-driven protection, both in vivo and in vitro, resulted from targeting PPARγ. First, LUT-induced Arg-1+ microglia were no longer detected when PPARγ was blocked. Next, LUT-mediated inhibition of the NLRP3 inflammasome and downregulation of pro-inflammatory cytokine production were reversed by the inhibition of PPARγ. Finally, the protective effects of LUT, which attenuated the microglial engulfment of synapses and prevented apparent synapse loss in the hippocampus of CRS-exposed mice, were eliminated by blocking PPARγ. In conclusion, this study showed that LUT ameliorates CRS-induced depressive-like behaviors by promoting the Arg-1+ microglial phenotype through a PPARγ-dependent mechanism, thereby alleviating microglial pro-inflammatory responses and reversing microglial phagocytosis-mediated synapse loss.

Effects of Fzd6 on intestinal flora and neuroinflammation in lipopolysaccharide-induced depression-like mice

BACKGROUND

The gut microbiome is critical for the pathophysiology of depression, and inflammation is one of the factors contributing to depression. Fzd6 has been implicated in depression. This study aimed to elucidate the effects of the Fzd6 mutation on gut microbiota structure and the possible regulatory mechanisms involved in depression-associated neuroinflammation.

METHODS

Wild-type (Fzd6WT) and Fzd6 mutant (Fzd6Q152E) male mice were treated with lipopolysaccharide (LPS) for 7 days. Behavioral experiments were used to detect the behavioral changes of mice in each group, and the composition of intestinal flora and systemic inflammation levels of mice were further detected.

RESULTS

In LPS mice, the Fzd6 mutation enhanced depression-like behavior symptoms, increased the release of pro-inflammatory cytokines, decreased the release of anti-inflammatory cytokines, and caused intestinal flora disturbance. Subsequently, 16SrRNA sequencing revealed significant changes in the relative abundance of the inflammation-associated bacterial groups Ruminococcaceae and Lachnospiraceae in Fzd6Q152E mice. In mice with depression, the levels of G protein-coupled receptors, GPR41 and GPR43, and glucagon-like peptide-1 (GLP-1) in the small intestine were down-regulated, and the expression of GLP-1 receptor (GLP-1R), peroxisome proliferators activated receptors gamma (PPAR-γ), and nuclear factor kappa-B inhibitor alpha (IκBα) in the hippocampus was also down-regulated, while the expression of nuclear factor kappa-B p65 (NF-κB p65) was up-regulated.

LIMITATIONS

The size of the spleen was not studied in this model, and the Fzd6 mutation itself does not cause systemic inflammation such as IL-6.

CONCLUSION

These results demonstrate that mutations in Fzd6 regulate the composition of the gut flora, which contributes to depression-associated inflammation.

Noradrenergic Locus Coeruleus-CA3 Activation Alleviates Neuropathic Pain and Anxiety- and Depression-Like Behaviors by Suppressing Microglial Neuroinflammation in SNI Mice

OBJECTIVE

Neuropathic pain (NP) arises from neuroimmune interactions following nerve injury and is often accompanied by anxiety and depression. The aim of the study is to evaluate the effects of the noradrenergic locus coeruleus (LC), a key regulator of pain and emotional states, projects extensively to the hippocampus.

METHOD

We investigated the effects of chronic NP on LC integrity and its projections to the hippocampal CA3 region in spared nerve injury (SNI) mice with behavioral tests, immunohistochemistry, neurochemical analyses, and Gq-DREADD.

RESULTS

Chronic NP induced LC neuronal loss, reduced hippocampal norepinephrine (NE) release, and triggered microglial activation and neuroinflammation in CA3. Selective activation of LC-CA3 noradrenergic neurons using Gq-DREADD chemogenetics alleviated NP and comorbid anxiety- and depression-like behaviors. This intervention suppressed microglial activation, decreased proinflammatory cytokines (TNF-α and IL-1β), and restored NE levels in CA3.

CONCLUSION

Our findings highlighted the therapeutic potential of targeting LC-CA3 projections to mitigate chronic NP and its neuropsychiatric comorbidities via modulation of hippocampal neuroinflammation.

Exogenous L-fucose attenuates depression induced by chronic unpredictable stress: Implicating core fucosylation has an antidepressant potential

Core fucosylation is one of the most essential modifications of the N-glycans, catalyzed by α1,6-fucosyltransferase (Fut8), which transfers fucose from guanosine 5'-diphosphate (GDP)-fucose to the innermost N-acetylglucosamine residue of N-glycans in an α1-6 linkage. Our previous studies demonstrated that lipopolysaccharide (LPS) can induce a more robust neuroinflammatory response in Fut8 homozygous knockout (KO) (Fut8-/-) and heterozygous KO (Fut8+/-) mice contrasted to the wild-type (Fut8+/+) mice. Exogenous administration of L-fucose suppressed LPS-induced neuroinflammation. Numerous studies indicate that neuroinflammation plays a vital role in the development of depression. Here, we investigated whether core fucosylation regulates depression induced by chronic unpredictable stress (CUS), a well-established model for depression. Our results showed that Fut8+/- mice exhibited depressive-like behaviors and increased neuroinflammation earlier than Fut8+/+ mice. Administration of L-fucose significantly reduced CUS-induced depressive-like behaviors and pro-inflammatory cytokine levels in Fut8+/- mice. The L-fucose treatment produced antidepressant effects by attenuating the complex formation between gp130 and the interleukin-6 (IL-6) receptor and the JAK2/STAT3 signaling pathway. Notably, L-fucose treatment increased dendritic spine density and postsynaptic density protein 95 (PSD-95) expression, which were suppressed in CUS-induced depression. Furthermore, the effects of L-fucose on the CUS-induced depression were also observed in Fut8+/+ mice. Our results clearly demonstrate that L-fucose ameliorates neuroinflammation and synaptic defects in CUS-induced depression, implicating that core fucosylation has significant anti-neuroinflammatory activity and an antidepressant potential.

Natural products target pyroptosis for ameliorating neuroinflammation: A novel antidepressant strategy

BACKGROUND

Depression is a common mental disorder characterized by prolonged loss of interest and low mood, accompanied by symptoms such as sleep disturbances and cognitive impairments. In severe cases, there may be a tendency toward suicide. Depression can be caused by a series of highly complex pathological mechanisms; However, its key pathogenic mechanism remains unclear. As a novel programmed cell death (PCD) pathway and inflammatory cell death mode, pyroptosis involves a series of tightly regulated gene expression events. It may play a significant role in the pathogenesis and management of depression by modulating neuroinflammatory processes. In addition, a large number of studies have shown that various pharmacologically active natural products can regulate pyroptosis through multiple targets and pathways, demonstrating significant potential in the treatment of depression. These natural products offer advantages such as low costs and minimal side effects, making them a viable supplement or alternative to traditional antidepressants. In this review, we summarized recent research on natural products that regulate pyroptosis and neuroinflammation to improve depression. The aim of this review was to contribute to a scientific basis for the discovery and development of more natural antidepressants in the future.

METHODS

To review the antidepressant effects of natural products targeting pyroptosis-mediated neuroinflammation, data were collected from the Web of Science, ScienceDirect databases, and PubMed to classify and summarize the relationship between pyroptosis and neuroinflammation in depression, as well as the pharmacological mechanisms of natural products.

RESULTS

Multiple researches have revealed that pyroptosis-mediated neuroinflammation serves as a pivotal contributory factor in the pathological process of depression. Natural products, such as terpenoids, terpenes, phenylethanol glycosides, and alkaloids, have antidepressant effects by regulating pyroptosis to alleviate neuroinflammation.

CONCLUSION

We comprehensively reviewed the regulatory effects of natural products in depression-related pyroptosis pathways, providing a uniquely insightful perspective for the research, development, and application of natural antidepressants. However, future research should further explore the modulatory mechanisms of natural products in regulating pyroptosis, which is of great importance for the genration of effective antidepressants.

Central nervous system and immune cells interactions in cancer: unveiling new therapeutic avenues

Cancer remains a leading cause of mortality worldwide. Despite significant advancements in cancer research, our understanding of its complex developmental pathways remains inadequate. Recent research has clarified the intricate relationship between the central nervous system (CNS) and cancer, particularly how the CNS influences tumor growth and metastasis via regulating immune cell activity. The interactions between the central nervous system and immune cells regulate the tumor microenvironment via various signaling pathways, cytokines, neuropeptides, and neurotransmitters, while also incorporating processes that alter the tumor immunological landscape. Furthermore, therapeutic strategies targeting neuro-immune cell interactions, such as immune checkpoint inhibitors, alongside advanced technologies like brain-computer interfaces and nanodelivery systems, exhibit promise in improving treatment efficacy. This complex bidirectional regulatory network significantly affects tumor development, metastasis, patient immune status, and therapy responses. Therefore, understanding the mechanisms regulating CNS-immune cell interactions is crucial for developing innovative therapeutic strategies. This work consolidates advancements in CNS-immune cell interactions, evaluates their potential in cancer treatment strategies, and provides innovative insights for future research and therapeutic approaches.

Gastrodin promotes CNS myelinogenesis and alleviates demyelinating injury by activating the PI3K/AKT/mTOR signaling

Demyelination is a common feature of numerous neurological disorders including multiple sclerosis and leukodystrophies. Although myelin can be regenerated spontaneously following injury, this process is often inadequate, potentially resulting in neurodegeneration and exacerbating neurological dysfunction. Several drugs aimed at promoting the differentiation of oligodendrocyte precursor cells (OPCs) have yielded unsatisfactory clinical effects. A recent study has shifted the strategy of pro-OPC differentiation towards enhancing myelinogenesis. In this study we identified the pro-myelinating drug using a zebrafish model. Five traditional Chinese medicine monomers including gastrodin, paeoniflorin, puerarin, salidroside and scutellarin were assessed by bath-application in Tg (MBP:eGFP-CAAX) transgenic line at 1-5 dpf. Among the 5 monomers, only gastrodin exhibited significant pro-myelination activity. We showed that gastrodin (10 µM) enhanced myelin sheath formation and oligodendrocyte (OL) maturation without affecting the number of OLs. Gastrodin markedly increased the phosphorylation levels of PI3K, AKT, and mTOR in primary cultured OLs via direct interaction with PI3K. Co-treatment with the PI3K inhibitor LY294002 (5 µM) mitigated gastrodin-induced OL maturation. Furthermore, injection of gastrodin (100 mg·kg-1·d-1, i.p.) effectively facilitated remyelination in a lysophosphatidylcholine-induced demyelinating mouse model and alleviated demyelination in the experimental autoimmune encephalomyelitis mice. These results identify gastrodin as a promising therapeutic agent for demyelinating diseases and highlight the potential of the zebrafish model for screening pro-myelinogenic pharmacotherapy.

Costunolide normalizes neuroinflammation and improves neurogenesis deficits in a mouse model of depression through inhibiting microglial Akt/mTOR/NF-κB pathway

Neuroinflammation is crucial for the pathogenesis of major depression. Preclinical studies have shown the potential of anti-inflammatory agents, specifically costunolide (COS), correlate with antidepressant effects. In this study, we investigated the molecular mechanisms underlying the antidepressant actions of COS. Chronic restraint stress (CRS) was induced in male mice. The mice were treated with either intra-DG injection of COS (5 μM, 1 μL per side) or COS (20 mg/kg, i.p.) for 1 week. We showed that administration of COS through the both routes significantly ameliorated the depressive-like behavior in CRS-exposed mice. Furthermore, administration of COS significantly improved chronic stress-induced adult hippocampal neurogenesis deficits in the mice through attenuating microglia-derived neuroinflammation. We demonstrated that COS (5 μM) exerted anti-neuroinflammatory effects in LPS-treated BV2 cells via inhibiting microglial Akt/mTOR/NF-κB pathway; inactivation of mTOR/NF-κB/IL-1β pathway was required for the pro-neurogenic action of COS in CRS-exposed mice. Our results reveal the antidepressant mechanism of COS that is normalizing neuroinflammation to improve neurogenesis deficits, supporting anti-inflammatory agents as a potential therapeutic strategy for depression.

Pharmacological Mechanism and Drug Research Prospects of Ginsenoside Rb1 as an Antidepressant

This review explores the antidepressant effects of ginsenoside Rb1, a natural compound in traditional Chinese medicine, and its potential for treating major depressive disorder (MDD). The aetiology of depression was reviewed up to 2024, focusing on the pathways and mechanisms through which ginsenoside Rb1 may exert its effects. Notably, ginsenoside Rb1 regulates oxidative stress and inflammatory processes while enhancing neural plasticity by downregulating miR-134 expression and alleviating depressive symptoms. Unlike traditional antidepressants that act on a single target, ginsenoside Rb1 interacts with multiple pathways, reflecting its potential for broader therapeutic application. To compensate for the current deficiency in animal experiments, clinical data, and research on the side effects of ginsenoside Rb1 in the treatment of depression, we reviewed some clinical data on the use of this component in the treatment of other diseases to explore its relevance to depression. Ginsenoside Rb1 is expected to serve as a novel antidepressant or as a complementary component in combination with other antidepressant compounds. However, further clinical trials and molecular studies are necessary to confirm its efficacy and potential side effects.

Detrimental influence of Arginase-1 in infiltrating macrophages on poststroke functional recovery and inflammatory milieu

Poststroke inflammation critically influences functional outcomes following ischemic stroke. Arginase-1 (Arg1) is considered a marker for anti-inflammatory macrophages, associated with the resolution of inflammation and promotion of tissue repair in various pathological conditions. However, its specific role in poststroke recovery remains to be elucidated. This study investigates the functional impact of Arg1 expressed in macrophages on poststroke recovery and inflammatory milieu. We observed a time-dependent increase in Arg1 expression, peaking at 7 d after photothrombotic stroke in mice. Cellular mapping analysis revealed that Arg1 was predominantly expressed in LysM-positive infiltrating macrophages. Using a conditional knockout (cKO) mouse model, we examined the role of Arg1 expressed in infiltrating macrophages. Contrary to its presumed beneficial effects, Arg1 cKO in LysM-positive macrophages significantly improved skilled forelimb motor function recovery after stroke. Mechanistically, Arg1 cKO attenuated fibrotic scar formation, enhanced peri-infarct remyelination, and increased synaptic density while reducing microglial synaptic elimination in the peri-infarct cortex. Gene expression analysis of fluorescence-activated single cell sorting (FACS)-sorted CD45low microglia revealed decreased transforming growth factor-β (TGF-β) signaling and proinflammatory cytokine activity in peri-infarct microglia from Arg1 cKO animals. In vitro coculture experiments demonstrated that Arg1 activity in macrophages modulates microglial synaptic phagocytosis, providing evidence for macrophage-microglia interaction. These findings present unique insights into the function of Arg1 in central nervous system injury and highlight an interaction between infiltrating macrophages and resident microglia in shaping the poststroke inflammatory milieu. Our study identifies Arg1 in macrophages as a potential therapeutic target for modulating poststroke inflammation and improving functional recovery.

Microglial Regulation of Neural Networks in Neuropsychiatric Disorders

Microglia serve as vital innate immune cells in the central nervous system, playing crucial roles in the generation and development of brain neurons, as well as mediating a series of immune and inflammatory responses. The morphologic transitions of microglia are closely linked to their function. With the advent of single-cell sequencing technology, the diversity of microglial subtypes is increasingly recognized. The intricate interactions between microglia and neuronal networks have significant implications for psychiatric disorders and neurodegenerative diseases. A deeper investigation of microglia in neurologic diseases such as Alzheimer disease, depression, and epilepsy can provide valuable insights in understanding the pathogenesis of diseases and exploring novel therapeutic strategies, thereby addressing issues related to central nervous system disorders.

Impact of natural compounds on peroxisome proliferator-activated receptor: Molecular effects and its importance as a novel therapeutic target for neurological disorders

Neurological disorders refer to the pathological changes of the nervous system involving multiple pathological mechanisms characterized by complex pathogenesis and poor prognosis. Peroxisome proliferator-activated receptor (PPAR) is a ligand-activated transcription factor that is a member of the nuclear receptor superfamily. PPAR has attracted considerable attention in the past decades as one of the potential targets for the treatment of neurological disorders. Several in vivo and in vitro studies have confirmed that PPARs play a neuroprotective role by regulating multiple pathological mechanisms. Several selective PPAR ligands, such as thiazolidinediones and fibrates, have been approved as pharmacological agonists. Nevertheless, PPAR agonists cause a variety of adverse effects. Some natural PPAR agonists, including wogonin, bergenin, jujuboside A, asperosaponin VI, monascin, and magnolol, have been introduced as safe agonists, as evidenced by clinical or preclinical experiments. This review summarizes the effects of phytochemicals on PPAR receptors in treating various neurological disorders. Further, it summarizes recent advances in phytochemicals as potential, safe, and promising PPAR agonists to provide insights into understanding the PPAR-dependent and independent cascades mediated by phytochemicals. The phytochemicals exhibited potential for treating neurological disorders by inhibiting neuroinflammation, exerting anti-oxidative stress and anti-apoptotic activities, promoting autophagy, preventing demyelination, and reducing brain edema and neurotoxicity. This review presents data that will help clarify the potential mechanisms by which phytochemicals act as pharmacological agonists of PPARs in the treatment of neurological disorders. It also provides insights into developing new drugs, highlighting phytochemicals as potential, safe, and promising PPAR agonists. Additionally, this review aims to enhance understanding of both PPAR-dependent and independent pathways mediated by phytochemicals.

D30 Alleviates β2-Microglobulin-Facilitated Neurotoxic Microglial Responses in Isoflurane/Surgery-Induced Cognitive Dysfunction in Aged Mice

Postoperative cognitive dysfunction (POCD) is a common complication with no effective treatment in elderly patients. POCD, Alzheimer disease (AD), and many other cognitive diseases mostly involve neurotoxic microglia response, and recently, β2-microglobulin (B2M) has been suggested to play a pivotal role. A novel pyromeconic acid-styrene hybrid compound D30 was synthesized by our team and shown to be safe and effective in some neurodegenerative mouse models. In this study, we evaluated D30 on POCD and its potential mechanism. Fourteen- to 18-month-old male C57BL/6 mice were used to establish POCD through isoflurane anesthesia and surgery. The plasma of elderly patients was collected pre- and postoperatively. Primary mouse microglia were subjected to various stimulations in multiple experimental designs to imitate in vivo POCD-like conditions. Morris water maze, fear conditioning, western blot, immunofluorescent staining, and blood-brain barrier (BBB) permeability tests were conducted in this study. D30 administration significantly improved learning and memory in aged mice following POCD. Neurotoxic M1 microglia cells were dramatically increased following POCD, manifested as morphologically changing into fewer and shorter branches, enlarged somatic areas, and upregulated expression of iNOS and C1q. Notably, following POCD, B2M was significantly upregulated in the plasma and the brain. D30 treatment significantly suppressed these pathologic changes, by inhibiting the POCD-induced BBB breakdown while suppressing the surge of plasma B2M levels. D30 treatment suppressed POCD-induced surge of B2M and Aβ plaques in the brain and preserved adult hippocampal neurogenesis vulnerable to POCD. Furthermore, postoperative levels of B2M were significantly elevated over the preoperative levels in patients aged 80 years and over. In parallel with mouse plasma after POCD, the postoperative patient plasma was also much more effective at activating M1 microglia. Of note, this POCD plasma-induced activation of M1 microglia was largely prevented by D30 treatment. Taken together, by inhibiting the surge of plasma B2M, protecting BBB integrity, and reducing inflammatory response, D30 protected aged mice from B2M-facilitated POCD.

Immune mechanisms and shared immune targets in neurodegenerative diseases

The immune system plays a major part in neurodegenerative diseases. In some, such as multiple sclerosis, it is the primary driver of the disease. In others, such as Alzheimer disease, amyotrophic lateral sclerosis and Parkinson disease, it has an amplifying role. Immunotherapeutic approaches that target the adaptive and innate immune systems are being explored for the treatment of almost all neurological diseases, and the targets and approaches are often common across diseases. Microglia are the primary immune cells in the brain that contribute to disease pathogenesis, and are consequently a common immune target for therapy. Other therapeutic approaches target components of the peripheral immune system, such as regulatory T cells and monocytes, which in turn act within the CNS. This Review considers in detail how microglia, monocytes and T cells contribute to the pathogenesis of multiple sclerosis, Alzheimer disease, amyotrophic lateral sclerosis and Parkinson disease, and their potential as shared therapeutic targets across these diseases. The microbiome is also highlighted as an emerging therapeutic target that indirectly modulates the immune system. Therapeutic approaches being developed to target immune function in neurodegenerative diseases are discussed, highlighting how immune-based approaches developed to treat one disease could be applicable to multiple other neurological diseases.

Bridging immune-neurovascular crosstalk via the immunomodulatory microspheres for promoting neural repair

The crosstalk between immune cells and the neurovascular unit plays a pivotal role in neural regeneration following central nervous system (CNS) injury. Maintaining brain immune homeostasis is crucial for restoring neurovascular function. In this study, an interactive bridge was developed via an immunomodulatory hydrogel microsphere to link the interaction network between microglia and the neurovascular unit, thereby precisely regulating immune-neurovascular crosstalk and achieving neural function recovery. This immunomodulatory crosstalk microsphere (MP/RIL4) was composed of microglia-targeted RAP12 peptide-modified interleukin-4 (IL-4) nanoparticles and boronic ester-functionalized hydrogel using biotin-avidin reaction and air-microfluidic techniques. We confirmed that the immunomodulatory microspheres reduced the expression of pro-inflammatory factors including IL-1β, iNOS, and CD86, while upregulating levels of anti-inflammatory factors such as IL-10, Arg-1, and CD206 in microglia. In addition, injection of the MP/RIL4 significantly mitigated brain atrophy volume in a mouse model of ischemic stroke, promoted neurobehavioral recovery, and enhanced the crosstalk between immune cells and the neurovascular unit, thus increasing angiogenesis and neurogenesis of stroke mice. In summary, the immunomodulatory microspheres, capable of orchestrating the interaction between immune cells and neurovascular unit, hold considerable therapeutic potential for ischemic stroke and other CNS diseases.

Insufficient Evidence to Recommend Shu Mian Capsule in Managing Depression With or Without Comorbid Insomnia: A Systematic Review With Meta-Analysis and Trial Sequential Analysis

Aim

This systematic review with trial sequential analysis (TSA) aims to evaluate the efficacy and safety of Shu Mian Capsule (SMC), a commercial Chinese polyherbal preparation, for managing depression with or without comorbid insomnia.

Methods

Controlled clinical trials assessing SMC against waitlist control, placebo or active controls, or as an adjunct treatment were searched across seven databases. Risk of bias and evidence quality were assessed using Cochrane criteria and GRADE framework, respectively.

Results

Fourteen studies were analyzed, involving 1207 participants. Trials comparing SMC with placebo or standard antidepressive treatments were limited. In depressed patients without comorbid insomnia, combining SMC with antidepressants reduced the incidence of antidepressants-induced sleep disorders (from 12.2% to 3.8%) but did not significantly lower Hamilton Rating Scale for Depression (HAM-D) scores compared to antidepressants alone [SMD = -0.09, 95% CI (-0.32, 0.14), p = 0.45]. In depressed patients with comorbid insomnia, the combination of SMC and psychotropic drugs significantly reduced HAM-D [SMD = -1.29, 95% CI (-1.96, -0.62), p < 0.01] and Pittsburgh Sleep Quality Index scores [SMD = -1.53, 95% CI (-1.95, -1.11), p < 0.01], and exhibited a lower incidence of various drug-related adverse effects compared to psychotropic drugs alone. TSA validated the sample size adequacy; nevertheless, the methodological quality of supporting studies varied from very low to low due to substantial bias risk. Additionally, 92.9% of trials lacked follow-ups.

Conclusion

The effectiveness of SMC as an alternative to conventional antidepressive treatment is unclear. For depressed patients with comorbid insomnia, adding SMC to standard care demonstrates augmented efficacy and improved safety, though the supporting evidence is methodologically limited. Further rigorous trials are warranted to confirm SMC's short-term efficacy and explore its medium- to long-term effects as either an alternative or complementary therapy. Current evidence precludes recommendations for the administration of SMC in depression.

The RNA Demethyltransferase FTO Regulates Ferroptosis in Major Depressive Disorder

Major depressive disorder (MDD) is a widespread and severe mental health condition characterized by persistent low mood and loss of interest. Emerging evidence suggests that ferroptosis, an iron-dependent form of cell death, and epigenetic dysregulation contribute to the pathogenesis of MDD. This study investigates the role of RNA demethylase FTO and autophagy regulator BECN1 in ferroptosis and their regulation by the active compound ginsenoside Rb1 (GRb1) as a potential antidepressant strategy. Hippocampal tissues from postmortem MDD patient brains and mice with chronic restraint stress (CRS)-induced depression were analyzed. Ferroptosis was evaluated by analyzing the levels of markers such as glutathione (GSH) and malondialdehyde (MDA). GRb1 was administered to CRS model mice by gavage to explore its effects on ferroptosis-related pathways. The results showed that FTO and BECN1 expression was reduced in the hippocampal tissues of MDD patients and CRS model mice, promoting ferroptosis via disruption of the antioxidant system. Moreover, GRb1 treatment increased FTO and BECN1 expression, modulated m6A methylation, restored the antioxidant balance, and inhibited ferroptosis in CRS model mice. These findings reveal a novel epigenetic mechanism of ferroptosis in MDD and highlight GRb1 as a promising agent for treating depression through the targeting of ferroptosis pathways.

The immunological perspective of major depressive disorder: unveiling the interactions between central and peripheral immune mechanisms

Major depressive disorder is a prevalent mental disorder, yet its pathogenesis remains poorly understood. Accumulating evidence implicates dysregulated immune mechanisms as key contributors to depressive disorders. This review elucidates the complex interplay between peripheral and central immune components underlying depressive disorder pathology. Peripherally, systemic inflammation, gut immune dysregulation, and immune dysfunction in organs including gut, liver, spleen and adipose tissue influence brain function through neural and molecular pathways. Within the central nervous system, aberrant microglial and astrocytes activation, cytokine imbalances, and compromised blood-brain barrier integrity propagate neuroinflammation, disrupting neurotransmission, impairing neuroplasticity, and promoting neuronal injury. The crosstalk between peripheral and central immunity creates a vicious cycle exacerbating depressive neuropathology. Unraveling these multifaceted immune-mediated mechanisms provides insights into major depressive disorder's pathogenic basis and potential biomarkers and targets. Modulating both peripheral and central immune responses represent a promising multidimensional therapeutic strategy.

Differential effects of chronic unpredictable stress on behavioral and molecular (cortisol and microglia-related neurotranscriptomic) responses in adult leopard (leo) zebrafish

Stress plays a key role in mental, neurological, endocrine, and immune disorders. The zebrafish (Danio rerio) is rapidly gaining popularity as s model organism in stress physiology and neuroscience research. Although the leopard (leo) fish are a common outbred zebrafish strain, their behavioral phenotypes and stress responses remain poorly characterized. Here, we examined the effects of a 5-week chronic unpredictable stress (CUS) exposure on adult leo zebrafish behavior, cortisol levels, and brain gene expression. Compared to their unstressed control leo counterparts, CUS-exposed fish showed paradoxically lower anxiety-like, but higher whole-body cortisol levels and altered expression of multiple pro- and anti-inflammatory brain genes. Taken together, these findings suggest that behavioral and physiological (endocrine and genomic) responses to CUS do differ across zebrafish strains. These findings add further complexity to systemic effects of chronic stress in vivo and also underscore the importance of considering the genetic background of zebrafish in stress research.

A machine learning-based analysis for the effectiveness of online teaching and learning in Pakistan during COVID-19 lockdown

BACKGROUND

The COVID-19 pandemic has significantly disrupted daily life and education, prompting institutions to adopt online teaching.

OBJECTIVE

This study delves into the effectiveness of these methods during the lockdown in Pakistan, employing machine learning techniques for data analysis.

METHODS

A cross-sectional online survey was conducted with 300 respondents using a semi-structured questionnaire to assess perceptions of online education. Artificial intelligence methods analyzed the specificity, sensitivity, accuracy, and precision of the collected data.

RESULTS

Among participants, 42.3% expressed satisfaction with online learning, while 49.3% preferred using Zoom. Convenience was noted with 72% favoring classes between 8 AM and 12 PM. The survey revealed 87.33% felt placement activities were negatively impacted, and 85% reported effects on individual growth. Additionally, 90.33% stated that online learning disrupted their routines, with 84.66% citing adverse effects on physical health. The Decision Tree classifier achieved the highest accuracy at 86%. Overall, preferences leaned toward traditional in-person teaching despite satisfaction with online methods.

CONCLUSIONS

The study highlights the significant challenges in transitioning to online education, emphasizing disruptions to daily routines and overall well-being. Notably, age and gender did not significantly influence perceptions of growth or health. Finally, collaborative efforts among educators, policymakers, and stakeholders are crucial for ensuring equitable access to quality education in future crises.

Automated analysis of a novel object recognition test in mice using image processing and machine learning

The novel object recognition test (NORT) is one of the most commonly employed behavioral tests in experimental animals designed to evaluate an animal's interest in and recognition of novelty. However, manual procedures, which rely on researchers' observations, prevent high throughput analysis. In this study, we developed an automated analysis method for NORT utilizing machine learning-assisted exploratory behavior detection. We recorded the exploratory behavior of the mice using a video camera. The coordinates of the mouse nose and tail base in recorded video files were detected using a pre-trained machine learning model, DeepLabCut. Each video was then segmented into frame images, which were categorized into "exploratory," or "non-exploratory" frames based on manual observation. Mouse feature vectors were calculated as vectors from the nose to the vertices of the object and were utilized for SVM training. The trained SVM effectively detected exploratory behaviors, showing a strong correlation with human observer assessments. Upon application to NORT, the duration of mouse exploratory behavior towards objects predicted by the SVM exhibited a significant correlation with the assessments made by human observers. The novelty discrimination index derived from the SVM predictions also aligned well with that from human observations.