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AbstractContextMethodsResultsDiscussion and ConclusionInflammasome NLR family pyrin domain-containing 3 (NLRP3) is associated with neurological disorders. Neuroinflammation can be suppressed by inhibiting NLRP3 inflammasome activation, decreasing neurodegenerative disorder progression. We devised a therapeutic technique that can reduce neuroinflammation induced by microglial activation, avoiding neurodegeneration. We aimed to investigate the mechanisms underlying the pharmacological effects of galantamine and wedelolactone by evaluating the response of the nuclear factor kappa B (NF-κB) signaling pathway and NLRP3 inflammasome in lipopolysaccharide (LPS)-activated N9 microglia.LPS and adenosine triphosphate were used to activate the NLRP3 inflammasome in N9 microglial cells, which were pretreated with galantamine and wedelolactone. Caspase-1, NLRP3, NF-κB, and interleukin (IL)-1β levels were measured using RT-qPCR and immunostaining.Combined administration of galantamine and wedelolactone rescued microglial cells from LPS-induced cell death. Furthermore, treatment with galantamine and wedelolactone led to the suppression of NF-κB expression. NLRP3, caspase-1, and IL-1β levels were decreased by the combined treatment.The concurrent administration of galantamine and wedelolactone effectively suppresses the production of inflammatory cytokines and NLRP3 inflammasome activation in microglia. This inhibitory effect is likely linked to the NF-κB signaling pathway modulation. Therefore, this combined treatment is a potential therapeutic approach for neuroinflammatory diseases. [ABSTRACT FROM AUTHOR]

Particulate matter (PM2.5) containing polycyclic aromatic hydrocarbons (PAHs) is of considerable environmental importance worldwide due to its adverse effects on human health, which are associated with neurodegenerative diseases (NDDs). Areca catechu L. (AC) fruit is known to possess various pharmacological properties; however, the anti-neuroinflammatory roles of AC on the suppression of PAH-induced neuroinflammation are still limited. Thus, we focused on the effects and related signaling cascades of AC and its active compounds against anthracene-induced toxicity and inflammation in mouse microglial BV-2 cells. Phytochemicals in the ethanolic extract of AC (ACEE) were identified using LC-MS, and molecular docking was conducted to screen the interaction between compounds and target proteins. Significant bioactive compounds in ACEE such as arecoline, (−)-epicatechin, and syringic acid were evinced through the LC-MS spectrum. The docking study revealed that (−)-epicatechin showed the highest binding affinities against NF-κB. For cell-based approaches, anthracene induced intracellular ROS, mRNA levels of TNF-α, IL-1β, and IL-6, and the release of TNF-α through enhancing JNK, p38, and NF-κB signaling pathways. However, the co-treatment of cells with ACEE or (−)-epicatechin could reverse those anthracene-induced changes. The overall study suggested that ACEE-derived bioactive compounds such as (−)-epicatechin may be developed as a potential anti-neuroinflammatory agent by preventing inflammation-mediated NDDs. [ABSTRACT FROM AUTHOR]

Periodontitis is associated with various systemic diseases, potentially facilitated by the passage of Porphyromonas gingivalis outer membrane vesicles (Pg-OMVs). Several recent studies have suggested a connection between Pg-OMVs and neuroinflammation and neurodegeneration, but the precise causal relationship remains unclear. This study aimed to investigate the mechanisms underlying these associations using in vitro models. Isolated Pg-OMVs were characterized by morphology, size, and gingipain activity. We exposed SH-SY5Y neuroblastoma cells and BV-2 microglial cells to various concentrations of Pg-OMVs. Cell morphology, a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, an enzyme-linked immunosorbent assay, and Western blot analysis were used to evaluate the cellular mechanism underlying Pg-OMV-induced neurotoxicity in neuronal cells and inflammatory responses in microglial cells. Exposure to Pg-OMVs induced neurotoxicity in SH-SY5Y cells, as evidenced by cellular shrinkage, reduced viability, activation of apoptotic pathways, and diminished neuronal differentiation markers. Gingipain inhibition mitigated these effects, suggesting that gingipain mediates Pg-OMVs-induced neurotoxicity in SH-SY5Y cells. Our research on neuroinflammation suggests that upon endocytosis of Pg-OMVs by BV-2 cells, lipopolysaccharide (LPS) can modulate the production of inducible nitric oxide synthase and tumor necrosis factor-alpha by activating pathways that involve phosphorylated AKT and the phosphorylated JNK pathway. Our study demonstrated that following the endocytosis of Pg-OMVs, gingipain can induce neurotoxicity in SH-SY5Y cells. Furthermore, the Pg-OMVs-associated LPS can trigger neuroinflammation via AKT and JNK signaling pathways in BV-2 cells. [ABSTRACT FROM AUTHOR]

Background/purpose: Periodontitis is associated with various systemic diseases, potentially facilitated by the passage of Porphyromonas gingivalis outer membrane vesicles (Pg-OMVs). Several recent studies have suggested a connection between Pg-OMVs and neuroinflammation and neurodegeneration, but the precise causal relationship remains unclear. This study aimed to investigate the mechanisms underlying these associations using in vitro models. Materials and methods: Isolated Pg-OMVs were characterized by morphology, size, and gingipain activity. We exposed SH-SY5Y neuroblastoma cells and BV-2 microglial cells to various concentrations of Pg-OMVs. Cell morphology, a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, an enzyme-linked immunosorbent assay, and Western blot analysis were used to evaluate the cellular mechanism underlying Pg-OMV-induced neurotoxicity in neuronal cells and inflammatory responses in microglial cells. Results: Exposure to Pg-OMVs induced neurotoxicity in SH-SY5Y cells, as evidenced by cellular shrinkage, reduced viability, activation of apoptotic pathways, and diminished neuronal differentiation markers. Gingipain inhibition mitigated these effects, suggesting that gingipain mediates Pg-OMVs-induced neurotoxicity in SH-SY5Y cells. Our research on neuroinflammation suggests that upon endocytosis of Pg-OMVs by BV-2 cells, lipopolysaccharide (LPS) can modulate the production of inducible nitric oxide synthase and tumor necrosis factor-alpha by activating pathways that involve phosphorylated AKT and the phosphorylated JNK pathway. Conclusion: Our study demonstrated that following the endocytosis of Pg-OMVs, gingipain can induce neurotoxicity in SH-SY5Y cells. Furthermore, the Pg-OMVs-associated LPS can trigger neuroinflammation via AKT and JNK signaling pathways in BV-2 cells.

BACKGROUND: Indolepropionic acid has been shown to reduce diabetes-induced central nervous system inflammation. However, there is a lack of research on whether to inhibit microglia M1 polarization for the treatment of spinal cord injury. OBJECTIVE: To investigate the mechanism of indolepropionic acid inhibition of microglial cell M1 polarization for the treatment of spinal cord injury through cell and animal experiments. METHODS: (1) In vitro experiments: BV2 cell viability was assessed using the CCK-8 assay to determine optimal concentrations of indolepropionic acid. Subsequently, BV2 cells were categorized into control group, administration group (50 μmol/L indolepropionic acid), lipopolysaccharide group (100 ng/mL lipopolysaccharide), and treatment group (100 ng/mL lipopolysaccharide + 50 μmol/L indolepropionic acid). Nitric oxide content was quantified using the Griess method. Real-time quantitative PCR and western blot assay were employed to measure mRNA and protein levels of pro-inflammatory factors. Cell immunofluorescence staining was conducted to assess inducible nitric oxide synthase expression. The Seahorse assay was employed to assess glycolytic stress levels in BV2 cells. (2) In vivo experiments: 30 SD rats were randomly divided into three groups: sham surgery group, spinal cord injury group, and indolepropionic acid group. Motor function recovery in rats after spinal cord injury was assessed using BBB scoring and the inclined plane test. Immunofluorescence staining of spinal cord tissue was conducted to evaluate the expression of inducible nitric oxide synthase in microglial cells. ELISA was employed to measure protein expression levels of the pro-inflammatory cytokines interleukin-1β and tumor necrosis factor-α in spinal cord tissue. RESULTS AND CONCLUSION: (1) In vitro experiments: Indolepropionic acid exhibited significant suppression of BV2 cell viability when its concentration exceeded 50 μmol/L. Indolepropionic acid achieved this by inhibiting the activation of the nuclear factor κB signaling pathway, thereby suppressing the mRNA and protein expression levels of pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-α), as well as the M1 polarization marker, inducible nitric oxide synthase, in BV2 cells. Additionally, indolepropionic acid notably reduced the glycolytic level in BV2 cells induced by lipopolysaccharides. (2) In vivo experiments: Following indolepropionic acid intervention in spinal cord injury rats, there was a noticeable increase in BBB scores and the inclined plane test angle. There was also a significant decrease in the number of M1-polarized microglial cells in spinal cord tissue, accompanied by a marked reduction in the protein expression levels of pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-α). (3) These results conclude that indolepropionic acid promotes functional recovery after spinal cord injury by improving the inflammatory microenvironment through inhibition of microglia M1 polarization. [ABSTRACT FROM AUTHOR]

Background: Microglia, brain resident macrophages, play multiple roles in maintaining homeostasis, including immunity, surveillance, and protecting the central nervous system through their distinct activation processes. Identifying all types of microglia-driven populations is crucial due to the presence of various phenotypes that differ based on developmental stages or activation states. During embryonic development, the E8.5 yolk sac contains erythromyeloid progenitors that go through different growth phases, eventually resulting in the formation of microglia. In addition, microglia are present in neurological diseases as a diverse population. So far, no individual biomarker for microglia has been discovered that can accurately identify and monitor their development and attributes. Summary: Here, we highlight the newly defined biomarker of mouse microglia, UGT1A7C, which exhibits superior stability in expression during microglia development and activation compared to other known microglia biomarkers. The UGT1A7C sensing chemical probe labels all microglia in the 3xTG AD mouse model. The expression of Ugt1a7c is stable during development, with only a 4- fold variation, while other microglia biomarkers, such as Csf1r and Cx3cr1, exhibit at least a 10-fold difference. The UGT1A7C expression remains constant throughout its lifespan. In addition, the expression and activity of UGT1A7C are the same in response to different types of inflammatory activators’ treatment in vitro. Conclusion: We propose employing UGT1A7C as the representative biomarker for microglia, irrespective of their developmental state, age, or activation status. Using UGT1A7C can reduce the requirement for using multiple biomarkers, enhance the precision of microglia analysis, and even be utilized as a standard for gene/protein expression. [ABSTRACT FROM AUTHOR]

[INLINE:1] Epilepsy frequently leads to cognitive dysfunction and approaches to treatment remain limited. Although regular exercise effectively improves learning and memory functions across multiple neurological diseases, its application in patients with epilepsy remains controversial. Here, we adopted a 14-day treadmill-exercise paradigm in a pilocarpine injection-induced mouse model of epilepsy. Cognitive assays confirmed the improvement of object and spatial memory after endurance training, and electrophysiological studies revealed the maintenance of hippocampal plasticity as a result of physical exercise. Investigations of the mechanisms underlying this effect revealed that exercise protected parvalbumin interneurons, probably via the suppression of neuroinflammation and improved integrity of blood-brain barrier. In summary, this work identified a previously unknown mechanism through which exercise improves cognitive rehabilitation in epilepsy.

A major challenge for the efficient treatment of traumatic brain injury is the need for therapeutic molecules to cross the blood-brain barrier to enter and accumulate in brain tissue. To overcome this problem, researchers have begun to focus on nanocarriers and other brain-targeting drug delivery systems. In this review, we summarize the epidemiology, basic pathophysiology, current clinical treatment, the establishment of models, and the evaluation indicators that are commonly used for traumatic brain injury. We also report the current status of traumatic brain injury when treated with nanocarriers such as liposomes and vesicles. Nanocarriers can overcome a variety of key biological barriers, improve drug bioavailability, increase intracellular penetration and retention time, achieve drug enrichment, control drug release, and achieve brain-targeting drug delivery. However, the application of nanocarriers remains in the basic research stage and has yet to be fully translated to the clinic.

Heat shock protein 90 (Hsp90) is a family of chaperone proteins that consists of four isoforms: Hsp90α, Hsp90β, glucose-regulated protein 94 (Grp94), and tumor necrosis factor type 1 receptor-associated protein (TRAP1). They are involved in modulating the folding, maturation, and activation of their client proteins to regulate numerous intracellular signaling pathways. Previous studies demonstrated that pan-Hsp90 inhibitors reduce inflammatory signaling pathways resulting in a reduction of inflammation and pain but show toxicities in cancer-related clinical trials. Further, the role of Hsp90 isoforms in inflammation remains poorly understood. This study aimed to determine anti-inflammatory activities of Hsp90 isoforms selective inhibitors on the lipopolysaccharide (LPS)-induced inflammation in BV-2 cells, a murine microglial cell line. The production of inflammatory mediators such as nitric oxide (NO), interleukin 1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) was measured. We also investigated the impact of Hsp90 isoform inhibitors on the activation of nuclear factor kappa B (NF-κB), nuclear factor erythroid 2–related factor 2 (Nrf2), and mitogen-activated protein kinases (MAPKs). We found that selective inhibitors of Hsp90β reduced the LPS-induced production of NO, IL-1β, and TNF-α via diminishing the activation of NF-κB and Extracellular signal-regulated kinases (ERK) MAPK. The Hsp90α, Grp94, TRAP1 inhibitors had limited effect on the production of inflammatory mediators. These findings suggest that Hsp90β is the key player in LPS-induced neuroinflammation. Thereby providing a more selective drug target for development of medications involved in pain management that can potentially contribute to the reduction of adverse side effects associated with Hsp90 pan inhibitors.

Abstract Background and purpose Cerebral ischemia‒reperfusion injury causes significant harm to human health and is a major contributor to stroke-related deaths worldwide. Current treatments are limited, and new, more effective prevention and treatment strategies that target multiple cell components are urgently needed. Leucine-rich alpha-2 glycoprotein 1 (Lrg1) appears to be associated with the progression of cerebral ischemia‒reperfusion injury, but the exact mechanism of it is unknown. Methods Wild-type (WT) and Lrg1 knockout (Lrg1 −/−) mice were used to investigate the role of Lrg1 after cerebral ischemia‒reperfusion injury. The effects of Lrg1 knockout on brain infarct volume, blood‒brain barrier permeability, and neurological score (based on 2,3,5-triphenyl tetrazolium chloride, evans blue dye, hematoxylin, and eosin staining) were assessed. Single-cell RNA sequencing (scRNA-seq), immunofluorescence, and microvascular albumin leakage tests were utilized to investigate alterations in various cell components in brain tissue after Lrg1 knockout. Results Lrg1 expression was increased in various cell types of brain tissue after cerebral ischemia‒reperfusion injury. Lrg1 knockout reduced cerebral edema and infarct size and improved neurological function after cerebral ischemia‒reperfusion injury. Single-cell RNA sequencing analysis of WT and Lrg1 −/− mouse brain tissues after cerebral ischemia‒reperfusion injury revealed that Lrg1 knockout enhances blood‒brain barrier (BBB) by upregulating claudin 11, integrin β5, protocadherin 9, and annexin A2. Lrg1 knockout also promoted an anti-inflammatory and tissue-repairing phenotype in microglia and macrophages while reducing neuron and oligodendrocyte cell death. Conclusions Our results has shown that Lrg1 mediates numerous pathological processes involved in cerebral ischemia‒reperfusion injury by altering the functional states of various cell types, thereby rendering it a promising therapeutic target for cerebral ischemia‒reperfusion injury.

Particulate matter (PM2.5) containing polycyclic aromatic hydrocarbons (PAHs) is of considerable environmental importance worldwide due to its adverse effects on human health, which are associated with neurodegenerative diseases (NDDs). Areca catechu L. (AC) fruit is known to possess various pharmacological properties; however, the anti-neuroinflammatory roles of AC on the suppression of PAH-induced neuroinflammation are still limited. Thus, we focused on the effects and related signaling cascades of AC and its active compounds against anthracene-induced toxicity and inflammation in mouse microglial BV-2 cells. Phytochemicals in the ethanolic extract of AC (ACEE) were identified using LC-MS, and molecular docking was conducted to screen the interaction between compounds and target proteins. Significant bioactive compounds in ACEE such as arecoline, (−)-epicatechin, and syringic acid were evinced through the LC-MS spectrum. The docking study revealed that (−)-epicatechin showed the highest binding affinities against NF-κB. For cell-based approaches, anthracene induced intracellular ROS, mRNA levels of TNF-α, IL-1β, and IL-6, and the release of TNF-α through enhancing JNK, p38, and NF-κB signaling pathways. However, the co-treatment of cells with ACEE or (−)-epicatechin could reverse those anthracene-induced changes. The overall study suggested that ACEE-derived bioactive compounds such as (−)-epicatechin may be developed as a potential anti-neuroinflammatory agent by preventing inflammation-mediated NDDs.

Background and purpose: Cerebral ischemia‒reperfusion injury causes significant harm to human health and is a major contributor to stroke-related deaths worldwide. Current treatments are limited, and new, more effective prevention and treatment strategies that target multiple cell components are urgently needed. Leucine-rich alpha-2 glycoprotein 1 (Lrg1) appears to be associated with the progression of cerebral ischemia‒reperfusion injury, but the exact mechanism of it is unknown. Methods: Wild-type (WT) and Lrg1 knockout (Lrg1−/−) mice were used to investigate the role of Lrg1 after cerebral ischemia‒reperfusion injury. The effects of Lrg1 knockout on brain infarct volume, blood‒brain barrier permeability, and neurological score (based on 2,3,5-triphenyl tetrazolium chloride, evans blue dye, hematoxylin, and eosin staining) were assessed. Single-cell RNA sequencing (scRNA-seq), immunofluorescence, and microvascular albumin leakage tests were utilized to investigate alterations in various cell components in brain tissue after Lrg1 knockout. Results: Lrg1 expression was increased in various cell types of brain tissue after cerebral ischemia‒reperfusion injury. Lrg1 knockout reduced cerebral edema and infarct size and improved neurological function after cerebral ischemia‒reperfusion injury. Single-cell RNA sequencing analysis of WT and Lrg1−/− mouse brain tissues after cerebral ischemia‒reperfusion injury revealed that Lrg1 knockout enhances blood‒brain barrier (BBB) by upregulating claudin 11, integrin β5, protocadherin 9, and annexin A2. Lrg1 knockout also promoted an anti-inflammatory and tissue-repairing phenotype in microglia and macrophages while reducing neuron and oligodendrocyte cell death. Conclusions: Our results has shown that Lrg1 mediates numerous pathological processes involved in cerebral ischemia‒reperfusion injury by altering the functional states of various cell types, thereby rendering it a promising therapeutic target for cerebral ischemia‒reperfusion injury. Highlights: Upregulated Lrg1 expression is observed in various cells in brain after cerebral ischemia‒reperfusion injury. Lrg1 knockout can attenuate brain damage and blood‒brain barrier dysfunction following cerebral ischemia‒reperfusion injury. Lrg1 knockout can alter the functional state of microglial cells towards the anti-inflammatory M2 phenotype. Lrg1 knockout can modulate the metabolic status of multiple cell types. [ABSTRACT FROM AUTHOR]

Objective. This study aimed to explore the effects of bone marrow mesenchymal stem cell (BMSC)-derived exosomal miR-146a-5p on microglial polarization and the potential underlying mechanisms in oxygen-glucose deprivation (OGD)-exposed microglial cells. Methods. Exosomes were isolated from BMSCs, and their characteristics were examined. The effects of BMSC-derived exosomes on microglial polarization were investigated in OGD-exposed BV-2 cells. Differentially expressed miRNAs were identified and their biological function was explored using enrichment analyses. The regulatory role of miR-146a-5p in microglial polarization was studied via flow cytometry. Finally, the downstream target gene Traf6 was validated, and the role of the miR-146a-5p/Traf6 axis in modulating microglial polarization was investigated in OGD-exposed BV-2 cells. Results. BMSC-derived exosomes were successfully isolated and characterized. A total of 10 upregulated and 33 downregulated miRNAs were identified. Exosomal treatment resulted in significant changes in microglial polarization markers. miR-146a-5p was found to be significantly downregulated in OGD-exposed microglial cells treated with exosomes. Manipulation of miR-146a-5p expression modulated microglial polarization. Moreover, the miR-146a-5p/Traf6 axis regulated microglial polarization. Conclusion. Our findings demonstrate that BMSC-derived exosomal via miR-146a-5p modulates microglial polarization by targeting Traf6, providing a potential thermal target for the treatment of neurological diseases involving microglial activation. [ABSTRACT FROM AUTHOR]

The active compound, 4-methoxycinnamyl p-coumarate (MCC), derived from the rhizome of Etlingera pavieana (Pierre ex Gagnep) R.M.Sm., has been shown to exert anti-inflammatory effects in several inflammatory models. However, its effects on microglial cells remain elusive. In the current study, we aimed to investigate the anti-neuroinflammatory activities of MCC and determine the potential mechanisms underlying its action on lipopolysaccharide (LPS)-induced BV2 microglial cells. Our results revealed that MCC significantly reduced the secretion of nitric oxide (NO) and prostaglandin E2, concomitantly inhibiting the expression levels of inducible NO synthase and cyclooxygenase-2 mRNA and proteins. Additionally, MCC effectively decreased the production of reactive oxygen species in LPS-induced BV2 microglial cells. MCC also attenuates the activation of NF-κB by suppressing the phosphorylation of IκBα and NF-κB p65 subunits and by blocking the nuclear translocation of NF-κB p65 subunits. Furthermore, MCC significantly reduced the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β). In addition, MCC markedly increased the expression of heme oxygenase-1 (HO-1) by upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Collectively, our findings suggest that the anti-inflammatory activities of MCC could be attributed to its ability to suppress the activation of NF-κB, MAPK, and Akt/GSK-3β while enhancing that of Nrf2-mediated HO-1. Accordingly, MCC has promising therapeutic potential to treat neuroinflammation-related diseases.

Background: Neuroinflammation and the activation of microglial cells are among the earliest events in Alzheimer's disease (AD). However, direct observation of microglia in living people is not currently possible. Here, we indexed the heritable propensity for neuroinflammation with polygenic risk scores (PRS), using results from a recent genome-wide analysis of a validated post-mortem measure of morphological microglial activation. Objective: We sought to determine whether a PRS for microglial activation (PRSmic) could augment the predictive performance of existing AD PRSs for late-life cognitive impairment. Methods: First, PRSmic were calculated and optimized in a calibration cohort (Alzheimer's Disease Neuroimaging Initiative (ADNI), n = 450), with resampling. Second, predictive performance of optimal PRSmic was assessed in two independent, population-based cohorts (total n = 212,237). Finally, we explored associations of PRSmic with a comprehensive set of imaging and fluid AD biomarkers in ADNI. Results: Our PRSmic showed no significant improvement in predictive power for either AD diagnosis or cognitive performance in either external cohort. Some nominal associations were found in ADNI, but with inconsistent effect directions. Conclusion: While genetic scores capable of indexing risk for neuroinflammatory processes in aging are highly desirable, more well-powered genome-wide studies of microglial activation are required. Further, biobank-scale studies would benefit from phenotyping of proximal neuroinflammatory processes to improve the PRS development phase. [ABSTRACT FROM AUTHOR]

BACKGROUND: Microglial cells are the predominant immune cells of the central nervous system and are important for the study of the development and treatment of many diseases. However, the methods for obtaining individualized cells in vitro are still lacking. OBJECTIVE: To establish a new microglia induction culture system to induce mouse corneal epithelial cells into microglia-like cells. METHODS: Corneal epithelial tissues of 2-week-old mice were lysed to obtain epithelial cells, and modified media containing interleukin-34 (100 ng/mL), colony stimulating factor 1 (5 ng/mL), transforming growth factor β (1 ng/mL), interleukin-6 (1 ng/mL), and recombinant vascular endothelial growth factor (1 ng/mL) were successively added. Treatment lasted up to 16 days. Cell properties were evaluated after induction by transcriptional level, protein expression level, subcellular localization, flow cytometry and morphological observation. RESULTS AND CONCLUSION: After induction, microglia-like cells which express characteristic molecules of TMEM119, CXCL11, CD11b and CD68 were obtained. Morphological observation, flow cytometry and fluorescence analysis confirmed that the expression products of TMEM119, CXCL11, CD11b and CD68 microglia had high abundance, which was very similar to microglia. [ABSTRACT FROM AUTHOR]

Turmeronols (A and B), bisabolane-type sesquiterpenoids found in turmeric, reduce inflammation outside the brain in animals; however, their effects on neuroinflammation, a common pathology of various neurodegenerative diseases, are not understood. Inflammatory mediators produced by microglial cells play a key role in neuroinflammation, so this study evaluated the anti-inflammatory effects of turmeronols in BV-2 microglial cells stimulated with lipopolysaccharide (LPS). Pretreatment with turmeronol A or B significantly inhibited LPSinduced nitric oxide (NO) production; mRNA expression of inducible NO synthase; production of interleukin (IL)-1β, IL-6, and tumor necrosis factor α and upregulation of their mRNA expression; phosphorylation of nuclear factor-κB (NF-κB) p65 proteins and inhibitor of NF-κB kinase (IKK); and nuclear translocation of NF-κB. These results suggest that these turmeronols may prevent the production of inflammatory mediators by inhibiting the IKK/NF-κB signaling pathway in activated microglial cells and can potentially treat neuroinflammation associated with microglial activation. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. In AD patients, amyloid-β (Aβ) peptide-mediated degeneration of the cholinergic system utilizing acetylcholine (ACh) for memory acquisition is observed. Since AD therapy using acetylcholinesterase (AChE) inhibitors are only palliative for memory deficits without reversing disease progress, there is a need for effective therapies, and cell-based therapeutic approaches should fulfil this requirement. We established F3.ChAT human neural stem cells (NSCs) encoding the choline acetyltransferase (ChAT) gene, an ACh-synthesizing enzyme, HMO6.NEP human microglial cells encoding the neprilysin (NEP) gene, an Aβ-degrading enzyme, and HMO6.SRA cells encoding the scavenger receptor A (SRA) gene, an Aβ-uptaking receptor. For the efficacy evaluation of the cells, first, we established an appropriate animal model based on Aβ accumulation and cognitive dysfunction. Among various AD models, intracerebroventricular (ICV) injection of ethylcholine mustard azirinium ion (AF64A) induced the most severe Aβ accumulation and memory dysfunction. Established NSCs and HMO6 cells were transplanted ICV to mice showing memory loss induced by AF64A challenge, and brain Aβ accumulation, ACh concentration and cognitive function were analyzed. All the transplanted F3.ChAT, HMO6.NEP and HMO6.SRA cells were found to survive up to 4 weeks in the mouse brain and expressed their functional genes. Combinational treatment with the NSCs (F3.ChAT) and microglial cells encoding each functional gene (HMO6.NEP or HMO6.SRA) synergistically restored the learning and memory function of AF64A-challenged mice by eliminating Aβ deposits and recovering ACh level. The cells also attenuated inflammatory astrocytic (glial fibrillary acidic protein) response by reducing Aβ accumulation. Taken together, it is expected that NSCs and microglial cells over-expressing ChAT, NEP or SRA genes could be strategies for replacement cell therapy of AD. [ABSTRACT FROM AUTHOR]

Liver dysfunction is the main cause of hepatic encephalopathy. However, histopathological changes in the brain associated with hepatic encephalopathy remain unclear. Therefore, we investigated pathological changes in the liver and brain using an acute hepatic encephalopathy mouse model. After administering ammonium acetate, a transient increase in the blood ammonia level was observed, which returned to normal levels after 24 h. Consciousness and motor levels also returned to normal. It was revealed that hepatocyte swelling, and cytoplasmic vacuolization progressed over time in the liver tissue. Blood biochemistry also suggested hepatocyte dysfunction. In the brain, histopathological changes, such as perivascular astrocyte swelling, were observed 3 h after ammonium acetate administration. Abnormalities in neuronal organelles, especially mitochondria and rough endoplasmic reticulum, were also observed. Additionally, neuronal cell death was observed 24 h post-ammonia treatment when blood ammonia levels had returned to normal. Activation of reactive microglia and increased expression of inducible nitric oxide synthase (iNOS) were also observed seven days after a transient increase in blood ammonia. These results suggest that delayed neuronal atrophy could be iNOS-mediated cell death due to activation of reactive microglia. The findings also suggest that severe acute hepatic encephalopathy causes continued delayed brain cytotoxicity even after consciousness recovery. [ABSTRACT FROM AUTHOR]

Microglial cells (MGs), originally derived from progenitor cells in a yolk sac during early development, are glial cells located in a physiological and pathological brain. Since the brain contains various cell types, MGs could frequently interact with different cells, such as astrocytes (ACs), pericytes (PCs), and endothelial cells (ECs). However, how microglial traits are regulated via cell–cell interactions by ACs, PCs, or ECs and how they are different depending on the contacted cell types is unclear. This study aimed to clarify these questions by coculturing MGs with ACs, PCs, or ECs using mouse brain-derived cells, and microglial phenotypic changes were investigated under culture conditions that enabled direct cell–cell contact. Our results showed that ACs or PCs dose-dependently increased the number of MG, while ECs decreased it. Microarray and gene ontology analysis showed that cell fate-related genes (e.g., cell cycle, proliferation, growth, death, and apoptosis) of MGs were altered after a cell–cell contact with ACs, PCs, and ECs. Notably, microarray analysis showed that several genes, such as gap junction protein alpha 1 (Gja1), were prominently upregulated in MGs after coincubation with ACs, PCs, or ECs, regardless of cell types. Similarly, immunohistochemistry showed that an increased Gja1 expression was observed in MGs after coincubation with ACs, PCs, or ECs. Immunofluorescent and fluorescence-activated cell sorting analysis also showed that calcein-AM was transferred into MGs after coincubation with ACs, PCs, or ECs, confirming that intercellular interactions occurred between these cells. However, while Gja1 inhibition reduced the number of MGs after coincubation with ACs and PCs, this was increased after coincubation with ECs; this indicates that ACs and PCs positively regulate microglial numbers via Gja1, while ECs decrease it. Results show that ACs, PCs, or ECs exert both common and specific cell type-dependent effects on MGs through intercellular interactions. These findings also suggest that brain microglial phenotypes are different depending on their surrounding cell types, such as ACs, PCs, or ECs. [ABSTRACT FROM AUTHOR]

We aim to deal with the Hub-genes and signalling pathways connected with Sepsis-associated encephalopathy (SAE). The raw datasets were acquired from the Gene Expression Omnibus (GEO) database (GSE198861 and GSE167610). R software filtered the differentially expressed genes (DEGs) for hub genes exploited for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Hub genes were identified from the intersection of DEGs via protein–protein interaction (PPI) network. And the single-cell dataset (GSE101901) was used to authenticate where the hub genes express in hippocampus cells. Cell–cell interaction analysis and Gene Set Variation Analysis (GSVA) analysis of the whole transcriptome validated the interactions between hippocampal cells. A total of 161 DEGs were revealed in GSE198861 and GSE167610 datasets. Biological function analysis showed that the DEGs were primarily involved in the phagosome pathway and significantly enriched. The PPI network extracted 10 Hub genes. The M2 Macrophage cell decreased significantly during the acute period, and the hub gene may play a role in this biological process. The hippocampal variation pathway was associated with the MAPK signaling pathway. Hub genes (Pecam1 , Cdh5 , Fcgr , C1qa , Vwf , Vegfa , C1qb , C1qc , Fcgr4 and Fcgr2b) may paticipate in the biological process of SAE. [ABSTRACT FROM AUTHOR]

Most studies of HIV latency focus on the peripheral population of resting memory T cells, but the brain also contains a distinct reservoir of HIV-infected cells in microglia, perivascular macrophages, and astrocytes. Studying HIV in the brain has been challenging, since live cells are difficult to recover from autopsy samples and primate models of SIV infection utilize viruses that are more myeloid-tropic than HIV due to the expression of Vpx. Development of a realistic small animal model would greatly advance studies of this important reservoir and permit definitive studies of HIV latency. When radiation or busulfan-conditioned, immune-deficient NSG mice are transplanted with human hematopoietic stem cells, human cells from the bone marrow enter the brain and differentiate to express microglia-specific markers. After infection with replication competent HIV, virus was detected in these bone marrow-derived human microglia. Studies of HIV latency in this model would be greatly enhanced by the development of compounds that can selectively reverse HIV latency in microglial cells. Our studies have identified members of the CoREST repression complex as key regulators of HIV latency in microglia in both rat and human microglial cell lines. The monoamine oxidase (MAO) and potential CoREST inhibitor, phenelzine, which is brain penetrant, was able to stimulate HIV production in human microglial cell lines and human glial cells recovered from the brains of HIV-infected humanized mice. The humanized mice we have developed therefore show great promise as a model system for the development of strategies aimed at defining and reducing the CNS reservoir.

Introduction: Extremely Low-Frequency Electromagnetic Fields (ELF-EMFs) have gathered significant consideration for their possible pathogenicity. However, their effects on the nervous system’s functions were not fully clarified. This study aimed to assay the impact of ELF-EMFs with different intensities on memory, anxiety, antioxidant activity, β-amyloid (Aβ) deposition, and microglia population in rats. Methods: Fifty male adult rats were randomly separated into 5 groups; 4 were exposed to a flux density of 1, 100, 500, and 2000 microtesla (µT), 50 Hz frequency for one h/day for two months, and one group as a control group. The control group was without ELF-EMF stimulation. After 8 weeks, passive avoidance and Elevated Plus Maze (EPM) tests were performed to assess memory formation and anxiety-like behavior, respectively. Total free thiol groups and the index of lipid peroxidation were evaluated. Additionally, for detection of Aβ deposition and stained microglia in the brain, anti-β-amyloid and anti-Iba1 antibodies were used. Results: The step-through latency in the retention test in ELF-EMF exposure groups (100500 & 2000 µT) was significantly greater than the control group (P

Traditional Chinese herbal medicine aiming at nourishing yin formed a distinctive school of thought in history to achieve anti-aging and longevity. In the formula Gancao nourishing yin (GCNY) decoction, all of the ingredients show antioxidant properties. However, in real clinical practice, extractions of herbs are rarely applied alone but are prescribed as the integrated formula. To investigate whether GCNY possesses anti-oxidation potential, we applied GCNY to treat rats to acquire medicated serum, which was then added on H2O2 (200 mM)-modeled human microglial cell line HMC-3 in comparison with its control serum. The results revealed that GCNY-medicated serum decreased reactive oxygen species (ROS) levels. Inflammatory cytokines such as pNF-κB p65 (ser536) and IL-6 were also decreased. Nrf2 and its pathwayrelated molecules, such as HO1, ABCC2, GLCM, ME1, NQO1, and TKT, were activated by H2O2 modeling while declined by treating with GCNYmedicated serum, which indicated attenuated oxidative stress of GCNY. Furthermore, mRNA-seq analysis showed 58 differential expressed genes (DEGs), which were enriched in pathways including antigen processing and presentation, longevity regulation, oxidative phosphorylation, and Parkinson's disease progression. DEGs that were downregulated by H2O2 modeling but upregulated by GCNY treatment include CENPF, MKI67, PRR11, andTOP2A. Those targets were reported to be associated with the cell cycle and cell proliferation and belong to the category of growth factor genes. In conclusion, this study verified anti-oxidation effects of GCNY and indicated its promising application for cognitive degeneration and aging-related disorders. [ABSTRACT FROM AUTHOR]

Diazepam binding inhibitor (DBI)‐translocator protein (18kDa) (TSPO) signaling in the retina was reported to possess coordinated macroglia‐microglia interactions. We investigated DBI‐TSPO signaling and its correlation with vascular endothelial growth factor (VEGF), neurotrophic or inflammatory cytokines in neovascular retinopathy, and under hypoxic conditions. The vitreous expression of DBI, VEGF, nerve growth factor (NGF), and interleukin‐1beta (IL‐1β) were examined in proliferative diabetic retinopathy (PDR) patients with or without anti‐VEGF therapy and nondiabetic controls. Retinal DBI‐TSPO signaling and the effect of the anti‐VEGF agent were evaluated in a mouse model of oxygen‐induced retinopathy (OIR). Interactions between Müller cell‐derived VEGF and DBI, as well as cocultured microglial cells under hypoxic conditions, were studied, using Western blot, real‐time RT‐PCR, enzyme‐linked immunosorbent assay (ELISA), flow cytometry, and immunofluorescent labeling. Results showed that vitreous levels of DBI, VEGF, NGF, and IL‐1β were significantly higher in PDR patients compared with controls, which further changed after anti‐VEGF therapy. A statistical association was found between vitreous DBI and VEGF, NGF, IL‐1β, and age. The application of the anti‐VEGF agent in the OIR model induced retinal expression of DBI and NGF, and attenuated inflammation and microglial cell activation. Inhibition of Müller cell‐derived VEGF could increase its DBI expression under hypoxic conditions, while the DBI‐TSPO signaling pathway is essential for anti‐VEGF agents exerting anti‐inflammatory and neuroprotective effects, as well as limiting inflammatory magnitude, promoting its neurotrophin production and anti‐inflammatory (M2) polarization in microglial cells. These findings suggest the beneficial effect of anti‐VEGF therapy on inflammation and neurotrophy of retinal glial cells through modulation of the DBI‐TSPO signaling pathway. [ABSTRACT FROM AUTHOR]

Traditional Chinese herbal medicine aiming at nourishing yin formed a distinctive school of thought in history to achieve anti-aging and longevity. In the formula Gancao nourishing yin (GCNY) decoction, all of the ingredients show antioxidant properties. However, in real clinical practice, extractions of herbs are rarely applied alone but are prescribed as the integrated formula. To investigate whether GCNY possesses anti-oxidation potential, we applied GCNY to treat rats to acquire medicated serum, which was then added on H2O2 (200 μM)-modeled human microglial cell line HMC-3 in comparison with its control serum. The results revealed that GCNY-medicated serum decreased reactive oxygen species (ROS) levels. Inflammatory cytokines such as pNF-κB p65 (ser536) and IL-6 were also decreased. Nrf2 and its pathway-related molecules, such as HO1, ABCC2, GLCM, ME1, NQO1, and TKT, were activated by H2O2 modeling while declined by treating with GCNY-medicated serum, which indicated attenuated oxidative stress of GCNY. Furthermore, mRNA-seq analysis showed 58 differential expressed genes (DEGs), which were enriched in pathways including antigen processing and presentation, longevity regulation, oxidative phosphorylation, and Parkinson’s disease progression. DEGs that were downregulated by H2O2 modeling but upregulated by GCNY treatment include CENPF, MKI67, PRR11, and TOP2A. Those targets were reported to be associated with the cell cycle and cell proliferation and belong to the category of growth factor genes. In conclusion, this study verified anti-oxidation effects of GCNY and indicated its promising application for cognitive degeneration and aging-related disorders.

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases. In AD patients, amyloid-β (Aβ) peptide-mediated degeneration of the cholinergic system utilizing acetylcholine (ACh) for memory acquisition is observed. Since AD therapy using acetylcholinesterase (AChE) inhibitors are only palliative for memory deficits without reversing disease progress, there is a need for effective therapies, and cell-based therapeutic approaches should fulfil this requirement. We established F3.ChAT human neural stem cells (NSCs) encoding the choline acetyltransferase (ChAT) gene, an ACh-synthesizing enzyme, HMO6.NEP human microglial cells encoding the neprilysin (NEP) gene, an Aβ-degrading enzyme, and HMO6.SRA cells encoding the scavenger receptor A (SRA) gene, an Aβ-uptaking receptor. For the efficacy evaluation of the cells, first, we established an appropriate animal model based on Aβ accumulation and cognitive dysfunction. Among various AD models, intracerebroventricular (ICV) injection of ethylcholine mustard azirinium ion (AF64A) induced the most severe Aβ accumulation and memory dysfunction. Established NSCs and HMO6 cells were transplanted ICV to mice showing memory loss induced by AF64A challenge, and brain Aβ accumulation, ACh concentration and cognitive function were analyzed. All the transplanted F3.ChAT, HMO6.NEP and HMO6.SRA cells were found to survive up to 4 weeks in the mouse brain and expressed their functional genes. Combinational treatment with the NSCs (F3.ChAT) and microglial cells encoding each functional gene (HMO6.NEP or HMO6.SRA) synergistically restored the learning and memory function of AF64A-challenged mice by eliminating Aβ deposits and recovering ACh level. The cells also attenuated inflammatory astrocytic (glial fibrillary acidic protein) response by reducing Aβ accumulation. Taken together, it is expected that NSCs and microglial cells over-expressing ChAT, NEP or SRA genes could be strategies for replacement cell therapy of AD.

Gastrodin (Gas) is known to exhibit neuroprotective effects in Alzheimer's disease (AD). However, the detailed mechanism of action is still unclear. In the present study, we focused on the microbiome–gut–brain axis to investigate the mechanism of action of Gas using a D-galactose (Dgal)–induced AD model. Gas reversed the memory dysfunction of Dgal-administered mice. Neurons in the cerebral cortex and hippocampus were reduced in the Dgal-administered group, and the decrease of neurons was suppressed in 90 and 210 mg/kg Gas treatment groups. 16S rRNA sequence analysis was carried out to explore the composition of gut microbiota in fecal samples of mice. Gas treatment had a positive correlation with Firmicutes and had a negative correlation with Cyanobacteria, Proteobacteria, and Deferribaceters. Importantly, the LPS and proinflammatory cytokines in the brain increased in Dgal-administered mice, but these parameters recovered to normal levels after oral administration of Gas. To determine whether the microbiota–gut–brain axis is involved in the neuroprotective effect of Gas, the mice were given antibiotic cocktail before and during the trial period to decrease the gut microbiota of mice. The antibiotic cocktail partially eliminated the neuroprotective effect of Gas by changing the gut microbiome composition. These results indicated that Gas improves the memory of the AD mouse model via partly targeting the microbiota–gut–brain axis and mitigating neuron inflammation. [ABSTRACT FROM AUTHOR]

Microglial cells play important roles in inflammatory responses. The level of oxidative stress is a well-known marker of inflammation. Homeopathic medicines are often used clinically to alleviate inflammation. We evaluated the anti-oxidative effect of high dilutions of Arnica montana (Arnica m.), Arsenicum album (Arsenicum a.), and Lachesis mutus (Lachesis m.) on production of reactive oxygen species (ROS) in inflamed microglial cells in vitro. Microglial cells, on exposure to lipopolysaccharide (LPS), have induced production of ROS compared with resting cells. The dilutions significantly reduced the oxidative stress by decreasing the level of ROS produced. Arnica m. 1C, 3C, 5C, 7C, 9C, and 30C dilutions had a range of ROS reduction between 15 and 42.1%; Arsenicum a. 3C, 5C, 7C, 15C, and 30C dilutions had a range of ROS reduction between 17.6 and 35.3%; and Lachesis m. 3C, 5C, 7C, 9C, 15C, and 30C dilutions had a range of ROS reduction between 25 and 41.7%. To summarize, the dilutions with the greatest effect were Arnica m. 1C (42.1%), Arsenicum a. 30C (35.3%), and Lachesis m. 7C (41.7%). Arnica m., Arsenicum a., and Lachesis m. did not have the same effect on ROS production and were not dose-dependent. [ABSTRACT FROM AUTHOR]

Abundant reactive gliosis and neuroinflammation are typical pathogenetic hallmarks of brains in Parkinson's disease (PD) patients, but regulation mechanisms are poorly understood. We are interested in role of programmed death-1 (PD-1) in glial reaction, neuroinflammation and neuronal injury in PD pathogenesis. Using PD mouse model and PD-1 knockout (KO) mice, we designed wild-type-control (WT-CON), WT-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (WT-MPTP), PD-1-KO-control (KO-CON) and PD-1-KO-MPTP (KO-MPTP), and observed motor dysfunction of animal, morphological distribution of PD-1-positive cells, dopaminergic neuronal injury, glial activation and generation of inflammatory cytokines in midbrains by motor behavior detection, immunohistochemistry and western blot. WT-MPTP mouse model exhibited decrease of PD-1/Iba1-positive microglial cells in the substantia nigra compared with WT-CON mice. By comparison of four groups, PD-1 deficiency showed exacerbation in motor dysfunction of animals, decreased expression of TH protein and TH-positive neuronal protrusions. PD-1 deficiency enhanced microglial activation, production of proinflammatory cytokines like inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-1β and interleukin-6, and expression and phosphorylation of AKT and ERK1/2 in the substantia nigra of MPTP model. We concluded that PD-1 deficiency could aggravate motor dysfunction of MPTP mouse model by inducing microglial activation and neuroinflammation in midbrains, suggesting that PD-1 signaling abnormality might be possibly involved in PD pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract Background Neuroinflammation has been identified to be the key player in most neurodegenerative diseases. If neuroinflammation is left to be unresolved, chronic neuroinflammation will be establish. Such situation is due to the overly-activated microglia which have the tendency to secrete an abundance amount of pro-inflammatory cytokines into the neuron microenvironment. The abundance of pro-inflammatory cytokines will later cause toxic and death to neurons. Toll-like receptor 4 (TLR4)/MD-2 complex found on the cell surface of microglia is responsible for the attachment of LPS and activation of nuclear factor-κB (NF-κB) downstream signalling pathway. Albeit vitexin has been shown to possess anti-inflammatory property, however, little is known on its ability to bind at the binding site of TLR4/MD-2 complex of microglia as well as to be an antagonist for LPS. Results The present study reveals that both vitexin and donepezil are able to bind at the close proximity of LPS binding site located at the TLR4/MD-2 complex with the binding energy of − 4.35 and − 9.14 kcal/mol, respectively. During molecular dynamic simulations, both vitexin and donepezil formed stable complex with TLR4/MD-2 throughout the 100 ns time length with the root mean square deviation (RMSD) values of 2.5 Å and 4.0 Å, respectively. The root mean square fluctuation (RMSF) reveals that both compounds are stable. Interestingly, the radius of gyration (rGyr) for donepezil shows notable fluctuations when compare with vitexin. The MM-GBSA results showed that vitexin has higher binding energy in comparison with donepezil. Conclusions Taken together, the findings suggest that vitexin is able to bind at the binding site of TLR4/MD-2 complex with more stability than donepezil throughout the course of 100 ns simulation. Hence, vitexin has the potential to be an antagonist candidate for LPS.

Gastrodin (Gas) is known to exhibit neuroprotective effects in Alzheimer’s disease (AD). However, the detailed mechanism of action is still unclear. In the present study, we focused on the microbiome–gut–brain axis to investigate the mechanism of action of Gas using a D-galactose (Dgal)–induced AD model. Gas reversed the memory dysfunction of Dgal-administered mice. Neurons in the cerebral cortex and hippocampus were reduced in the Dgal-administered group, and the decrease of neurons was suppressed in 90 and 210 mg/kg Gas treatment groups. 16S rRNA sequence analysis was carried out to explore the composition of gut microbiota in fecal samples of mice. Gas treatment had a positive correlation with Firmicutes and had a negative correlation with Cyanobacteria, Proteobacteria, and Deferribaceters. Importantly, the LPS and proinflammatory cytokines in the brain increased in Dgal-administered mice, but these parameters recovered to normal levels after oral administration of Gas. To determine whether the microbiota–gut–brain axis is involved in the neuroprotective effect of Gas, the mice were given antibiotic cocktail before and during the trial period to decrease the gut microbiota of mice. The antibiotic cocktail partially eliminated the neuroprotective effect of Gas by changing the gut microbiome composition. These results indicated that Gas improves the memory of the AD mouse model via partly targeting the microbiota–gut–brain axis and mitigating neuron inflammation.

Microglial cells (MGs), originally derived from progenitor cells in a yolk sac during early development, are glial cells located in a physiological and pathological brain. Since the brain contains various cell types, MGs could frequently interact with different cells, such as astrocytes (ACs), pericytes (PCs), and endothelial cells (ECs). However, how microglial traits are regulated via cell–cell interactions by ACs, PCs, or ECs and how they are different depending on the contacted cell types is unclear. This study aimed to clarify these questions by coculturing MGs with ACs, PCs, or ECs using mouse brain-derived cells, and microglial phenotypic changes were investigated under culture conditions that enabled direct cell–cell contact. Our results showed that ACs or PCs dose-dependently increased the number of MG, while ECs decreased it. Microarray and gene ontology analysis showed that cell fate-related genes (e.g., cell cycle, proliferation, growth, death, and apoptosis) of MGs were altered after a cell–cell contact with ACs, PCs, and ECs. Notably, microarray analysis showed that several genes, such as gap junction protein alpha 1 (Gja1), were prominently upregulated in MGs after coincubation with ACs, PCs, or ECs, regardless of cell types. Similarly, immunohistochemistry showed that an increased Gja1 expression was observed in MGs after coincubation with ACs, PCs, or ECs. Immunofluorescent and fluorescence-activated cell sorting analysis also showed that calcein-AM was transferred into MGs after coincubation with ACs, PCs, or ECs, confirming that intercellular interactions occurred between these cells. However, while Gja1 inhibition reduced the number of MGs after coincubation with ACs and PCs, this was increased after coincubation with ECs; this indicates that ACs and PCs positively regulate microglial numbers via Gja1, while ECs decrease it. Results show that ACs, PCs, or ECs exert both common and specific cell type-dependent effects on MGs through intercellular interactions. These findings also suggest that brain microglial phenotypes are different depending on their surrounding cell types, such as ACs, PCs, or ECs.

To evaluate the effects of dexmedetomidine (Dex) and oxycodone (Oxy) on neurocognitive and inflammatory response after tourniquet-induced ischemia–reperfusion (I/R) injury. C57/BL6 mice were used to construct the mouse model of tourniquet-induced I/R injury. Mice (n = 48) were randomly divided into sham, I/R, Dex or Oxy group. Morris water maze test was performed to assess the spatial learning and memory function. The expression of NF-κB, TLR4, NR2B, M1 (CD68 and TNF-α) and M2 (CD206 and IL-10) polarization markers in mice hippocampus were detected by western blot or immunofluorescent staining. Spontaneous excitatory post-synaptic currents (sEPSCs) were recorded by electrophysiology. Dex treatment alleviated I/R-induced declines in learning and memory (p < 0.05), while Oxy had no significant effect on it. Compared with I/R group, Dex and Oxy treatment down-regulated the expression of NF-κB, TLR4, TNF-α and CD68 (all p < 0.05), while no significantly different was found in CD206 and IL-10. In addition, Dex treatment down-regulated the expression of NR2B and reduced the frequency and amplitude of sEPSCs in I/R model mice (all p < 0.05), while Oxy had no significant effect on them. Tourniquet-induced I/R could impair the neurocognitive function of mice. Dex treatment could alleviate I/R-induced neurocognitive disorder by inhibiting abnormal synaptic transmission in hippocampal neurons. Both Dex and Oxy could alleviate the inflammatory response likely by inhibiting the polarization of microglia toward M1 phenotype via TLR4/NF-κB pathway. Future studies are needed to further examine the effects of Dex on neurocognitive disorder after tourniquet-induced I/R injury and investigate the exact mechanism. [ABSTRACT FROM AUTHOR]

Background: Extremely low-frequency electromagnetic fields (ELF-EMFs) have gathered significant consideration for their possible pathogenicity. However, their effects on nervous system functions were not fully clarified. In this study, our aim was to assay the effect of ELF-EMFs with different intensity on memory, anxiety, antioxidant activity, beta amyloid (Aß) deposition and microglia population in rats. Materials and Methods: Fifty male adult rats were randomly separated into 5 groups; four groups exposed to a flux density of 1, 100, 500 and 2000 microtesla (µT), 50 Hertz (Hz) frequency for 1h/day for 2 months and one group as a control group. The control group were without ELF-EMF stimulation. After 8 weeks, passive avoidance and elevated plus maze (EPM) tests was performed to assess memory formation and anxiety-like behavior, respectively. Total free thiol groups and the index of lipid peroxidation were assessed. Also, for detection of ß-Amyloid deposition and stained microglia in the brain, anti-ß-amyloid and anti-Iba1 antibodies were used. Results: In the ELF-EMF exposure groups, the step-through latency was significantly greater in the retention test (100,500, and 2000 µT) than in the control group (P<0.05). Also, the percentage of the entries into the open arms in ELF-EMF exposure groups (especially 2000 µT) decreased than control group (P <0.05). No ß-Amyloid depositions were detected in the hippocampus of different groups. An increase in microglia numbers in the 100, 500 and 2000 µT groups was observed in compare to the control and 1 µT group. Conclusion: Exposure to ELF-EMF had an anxiogenic effect on rats and promoted memory and also induced oxidative stress. No ß-Amyloid depositions were detected in the brain. Also, positive effect of ELF-EMF was observed on population of microglia population in the brain. [ABSTRACT FROM AUTHOR]

Background Recently, researchers have considered extremely low-frequency electromagnetic fields (ELFEMFs), as one of the non-invasive therapies, in the treatment of many severe neurological disorders, including Alzheimer Disease (AD). AD is a progressive neurodegenerative disease characterized by the deposition of amyloid plaques in the brain. However, the increase in microglial cells increases phagocytosis and the destruction of amyloid plaques. Therefore, the present study aimed to investigate the amount of β-amyloid precursor deposition and the number of microglia cells in the animal model of AD before and after exposure to ELF-EMFs. Objective The aim of this study was to investigate the deposition of beta ameloid precursor and the number of microglial cells in the Alzheimer's animal model before and after exposure to magnetic waves. Methods Fifty male adult rats were randomly grouped into 5: The control group, the ELF-EMFs group, the AD group, the treatment group 1, and the treatment group 2. After the study period, the animals were killed for immunohistochemistry assessment to detect and compare the deposition of β-amyloid and the production of allograft inflammatory factor 1 (Iba1) protein. Results Exposure to ELF reduced the deposition of β-amyloid and increased microglia cells. However, these changes were not different between the control and ELF-EMFs groups (P<0.001). Conclusion ELF-EMF can reduce the formation of β-amyloid plaques and induce the proliferation of microglia cells. Therefore, they can be used to treat brain damage caused by Alzheimer disease. [ABSTRACT FROM AUTHOR]

Introduction Glycyrrhiza glabra is a plant used in traditional medicine across the world for its pharmacological value. Its value has been proved such as anti-cough, anti-diabetes, anti-microbial and antioxidant effects. Materials and Methods In this study the effect of a glycyrrhizin component of HMGB1's microglia product becomes in the survey, at terms of informative mediating on in vitro modeling that have six groups (with three replications). In negative control group no Gly and LPS was involved. In positive control group, the cells were induced with LPS and no Gly, and in 3, 4, 5 and 6 groups 0.2, 0.4, 1.2 and 4 µg/ml Gly were added respectively. The amounts of HMGB1 were measured at 24, 48 and 72 hours with the sandwich ELISA kit. Results At all three times, the HMGB1 were decreased with increasing Gly, but in 24 h between 0.2 and 1.2 concentrations and in 72 h between positive control and 0.2 no significant difference were found. So it is concluded that this amount should be increased for the effective dose. Conclusion Along with previous studies, Glycyrrhizin reduced the production of HMGB1 in the microglial cell line.

Heat shock protein 90 (Hsp90) is a family of chaperone proteins that consists of four isoforms: Hsp90α, Hsp90β, glucose-regulated protein 94 (Grp94), and tumor necrosis factor type 1 receptor-associated protein (TRAP1). They are involved in modulating the folding, maturation, and activation of their client proteins to regulate numerous intracellular signaling pathways. Previous studies demonstrated that pan-Hsp90 inhibitors reduce inflammatory signaling pathways resulting in a reduction of inflammation and pain but show toxicities in cancer-related clinical trials. Further, the role of Hsp90 isoforms in inflammation remains poorly understood. This study aimed to determine anti-inflammatory activities of Hsp90 isoforms selective inhibitors on the lipopolysaccharide (LPS)-induced inflammation in BV-2 cells, a murine microglial cell line. The production of inflammatory mediators such as nitric oxide (NO), interleukin 1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) was measured. We also investigated the impact of Hsp90 isoform inhibitors on the activation of nuclear factor kappa B (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), and mitogen-activated protein kinases (MAPKs). We found that selective inhibitors of Hsp90β reduced the LPS-induced production of NO, IL-1β, and TNF-α via diminishing the activation of NF-κB and Extracellular signal-regulated kinases (ERK) MAPK. The Hsp90α, Grp94, TRAP1 inhibitors had limited effect on the production of inflammatory mediators. These findings suggest that Hsp90β is the key player in LPS-induced neuroinflammation. Thereby providing a more selective drug target for development of medications involved in pain management that can potentially contribute to the reduction of adverse side effects associated with Hsp90 pan inhibitors., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Smith, Kliebe, Mishra, McCall, Irvine, Blagg and Lei.)

Background: Microglia, brain resident macrophages, play multiple roles in maintaining homeostasis, including immunity, surveillance, and protecting the central nervous system through their distinct activation processes. Identifying all types of microglia-driven populations is crucial due to the presence of various phenotypes that differ based on developmental stages or activation states. During embryonic development, the E8.5 yolk sac contains erythromyeloid progenitors that go through different growth phases, eventually resulting in the formation of microglia. In addition, microglia are present in neurological diseases as a diverse population. So far, no individual biomarker for microglia has been discovered that can accurately identify and monitor their development and attributes., Summary: Here, we highlight the newly defined biomarker of mouse microglia, UGT1A7C, which exhibits superior stability in expression during microglia development and activation compared to other known microglia biomarkers. The UGT1A7C sensing chemical probe labels all microglia in the 3xTG AD mouse model. The expression of Ugt1a7c is stable during development, with only a 4-fold variation, while other microglia biomarkers, such as Csf1r and Cx3cr1 , exhibit at least a 10-fold difference. The UGT1A7C expression remains constant throughout its lifespan. In addition, the expression and activity of UGT1A7C are the same in response to different types of inflammatory activators' treatment in vitro ., Conclusion: We propose employing UGT1A7C as the representative biomarker for microglia, irrespective of their developmental state, age, or activation status. Using UGT1A7C can reduce the requirement for using multiple biomarkers, enhance the precision of microglia analysis, and even be utilized as a standard for gene/protein expression., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Kim, Kim and Kim.)

Background: Neuroinflammation has been identified to be the key player in most neurodegenerative diseases. If neuroinflammation is left to be unresolved, chronic neuroinflammation will be establish. Such situation is due to the overly-activated microglia which have the tendency to secrete an abundance amount of pro-inflammatory cytokines into the neuron microenvironment. The abundance of pro-inflammatory cytokines will later cause toxic and death to neurons. Toll-like receptor 4 (TLR4)/MD-2 complex found on the cell surface of microglia is responsible for the attachment of LPS and activation of nuclear factor-κB (NF-κB) downstream signalling pathway. Albeit vitexin has been shown to possess anti-inflammatory property, however, little is known on its ability to bind at the binding site of TLR4/MD-2 complex of microglia as well as to be an antagonist for LPS. Results: The present study reveals that both vitexin and donepezil are able to bind at the close proximity of LPS binding site located at the TLR4/MD-2 complex with the binding energy of − 4.35 and − 9.14 kcal/mol, respectively. During molecular dynamic simulations, both vitexin and donepezil formed stable complex with TLR4/MD-2 throughout the 100 ns time length with the root mean square deviation (RMSD) values of 2.5 Å and 4.0 Å, respectively. The root mean square fluctuation (RMSF) reveals that both compounds are stable. Interestingly, the radius of gyration (rGyr) for donepezil shows notable fluctuations when compare with vitexin. The MM-GBSA results showed that vitexin has higher binding energy in comparison with donepezil. Conclusions: Taken together, the findings suggest that vitexin is able to bind at the binding site of TLR4/MD-2 complex with more stability than donepezil throughout the course of 100 ns simulation. Hence, vitexin has the potential to be an antagonist candidate for LPS. [ABSTRACT FROM AUTHOR]

Microglia are immune cells that are resident in central nervous system. Activation of microglial cells are detrimental to the survival of neurons. Thus, prevention of microglia activation and/or protection against microglia activation could be potential therapeutic strategy towards the management of inflammation-mediated neurodegenerative diseases. Moringa oleifera is widely consumed as food and used in folklore medicine for treating several diseases. This study was convened to investigate the effect of aqueous extract of Moringa oleifera on cell viability, cholinergic and purinergic enzymes in BV-2 microglial cultured cell. Aqueous extract of Moringa oleifera was prepared, lyophilized and reconstituted in 0.5% dimethylsulphoxide (DMSO). Cells were treated with Moringa oleifera extracts (0.1–100 μg/mL) and assessed for cell viability and nitric oxide production. Furthermore, the effect of Moringa oleifera on enzymes of cholinergic (acetylcholinesterase) and purinergic (nucleoside triphosphate diphosphohydrolase; NTPDase, 5′ nucleotidase and adenosine deaminase; ADA) systems in BV-2 microglial cells were determined. Incubation of BV-2 microglia cell with M. oleifera extract maintained cell viability, modulated cholinergic and purinergic enzymes activity. The phenolic compounds found in M. oleifera extracts, include chlorogenic acid, rutin; quercetin pentoside, kaempferol derivative and quercetin derivative. Thus, this study suggest that the potential therapeutic effect of the phenolic compounds found in M. oleifera may have been responsible for the maintenance of cell viability in BV-2 microglia cells and modulation of cholinergic as well as purinergic enzymes activity. [ABSTRACT FROM AUTHOR]

The voltage-gated proton channel Hv1 plays important roles in proton extrusion, pH homeostasis, and production of reactive oxygen species in a variety of cell types. Excessive Hv1 activity increases proliferation and invasiveness in cancer cells and worsens brain damage in ischemic stroke. The channel is composed of two subunits, each containing a proton-permeable voltage-sensing domain (VSD) and lacking the pore domain typical of other voltage-gated ion channels. We have previously shown that the compound 2-guanidinobenzimidazole (2GBI) inhibits Hv1 proton conduction by binding to the VSD from its intracellular side. Here, we examine the binding affinities of a series of 2GBI derivatives on human Hv1 channels mutated at positions located in the core of the VSD and apply mutant cycle analysis to determine how the inhibitor interacts with the channel. We identify four Hv1 residues involved in the binding: aspartate 112, phenylalanine 150, serine 181, and arginine 211. 2GBI appears to be oriented in the binding site with its benzo ring pointing to F150, its imidazole ring inserted between residue D112 and residues S181 and R211, and the guanidine group positioned in the proximity of R211. We also identify a modified version of 2GBI that is able to reach the binding site on Hv1 from the extracellular side of the membrane. Understanding how compounds like 2GBI interact with the Hv1 channel is an important step to the development of pharmacological treatments for diseases caused by Hv1 hyperactivity.

Epilepsy frequently leads to cognitive dysfunction and approaches to treatment remain limited. Although regular exercise effectively improves learning and memory functions across multiple neurological diseases, its application in patients with epilepsy remains controversial. Here, we adopted a 14-day treadmill-exercise paradigm in a pilocarpine injection-induced mouse model of epilepsy. Cognitive assays confirmed the improvement of object and spatial memory after endurance training, and electrophysiological studies revealed the maintenance of hippocampal plasticity as a result of physical exercise. Investigations of the mechanisms underlying this effect revealed that exercise protected parvalbumin interneurons, probably via the suppression of neuroinflammation and improved integrity of blood-brain barrier. In summary, this work identified a previously unknown mechanism through which exercise improves cognitive rehabilitation in epilepsy., Competing Interests: None

A major challenge for the efficient treatment of traumatic brain injury is the need for therapeutic molecules to cross the blood-brain barrier to enter and accumulate in brain tissue. To overcome this problem, researchers have begun to focus on nanocarriers and other brain-targeting drug delivery systems. In this review, we summarize the epidemiology, basic pathophysiology, current clinical treatment, the establishment of models, and the evaluation indicators that are commonly used for traumatic brain injury. We also report the current status of traumatic brain injury when treated with nanocarriers such as liposomes and vesicles. Nanocarriers can overcome a variety of key biological barriers, improve drug bioavailability, increase intracellular penetration and retention time, achieve drug enrichment, control drug release, and achieve brain-targeting drug delivery. However, the application of nanocarriers remains in the basic research stage and has yet to be fully translated to the clinic., Competing Interests: None

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Bone marrow stromal cells (MSCs) are a useful source of stem cells for the treatment of various brain injury diseases due to their abundant supply and fewer ethical problems compared with transplant treatment. However, the clinical application of MSCs is limited due to allograft rejection and immunosuppression in the process of MSCs transplantation. According to previous studies, microglial cell autophagy occurs following co-culture with MSCs. In the present study, exosomes were obtained from MSCs and subsequently characterized using transmission electron microscopy, atomic force microscopy and dynamic light scattering particle size analysis. The type of microRNAs (miRs) found in the exosomes was then analyzed via gene chip. The results demonstrated that microglial cell autophagy could be induced by exosomes. This mechanism was therefore investigated further via reverse transcription-quantitative PCR, western blotting and luciferase assays. These results demonstrated that exosomes from MSCs could induce microglial cell autophagy through the miR-32-mediated regulation of disabled homolog 2-interacting protein, thus providing a theoretical basis for the clinical application of miRs in MSCs. [ABSTRACT FROM AUTHOR]

• Hydrolytic selectivity of β-glucosidase determines minor ginseng saponins produced. • Hydrolytic selectivity depends on the position and linkage type of sugar residues. • rBGLa showed higher selectivity for P1, P4, and P2 residues of ginsenoside. • Hydrolytic selectivity led to selective production of desired minor ginsenosides. • Enhanced Rd, Rh1, and A-PPD alleviated neuroinflammation in BV2 microglial cells. Despite the inhibitory effect of various ginsenosides on neuroinflammation, pharmacological activity of ginsenosides varies depending on their hydrolysis by individual intestinal microbial flora and may not appear in individuals with intestinal microbial deficiency. Herein, we investigated the hydrolytic selectivity of β-glucosidase from Lactobacillus antri toward sugar residues in ginsenoside to selectively enhance the effective minor ginsenoside contents and improve their anti-neuroinflammatory activity in BV2 microglia. The hydrolytic selectivity of β-glucosidase was dependent on the position and linkage type of sugar residues. Hydrolysis of ginseng extract and its mimic indicated that the predominant hydrolytic selectivity of β-glucosidase toward P1 (β1→6 linkage), P4, and P2 residues led to the selective production of minor ginsenoside Rd at the early stage and Rg3, Rh1, and A-PPD at the late stage, which resulted in the enhanced anti-neuroinflammatory activity of hydrolyzed ginseng mimic by inhibiting the production of inflammatory mediators in BV2 microglial cells, particularly at the late stage of hydrolysis. This study suggests that the insight into the hydrolytic selectivity of β-glucosidase will help in selecting appropriate substrates hydrolyzed well and in enhancing the contents of desired deglycosylated compounds, including minor ginsenosides, to improve their efficacy on specific target diseases, including those caused by neuroinflammation. [ABSTRACT FROM AUTHOR]

The active compound, 4-methoxycinnamyl p -coumarate (MCC), derived from the rhizome of Etlingera pavieana (Pierre ex Gagnep) R.M.Sm., has been shown to exert anti-inflammatory effects in several inflammatory models. However, its effects on microglial cells remain elusive. In the current study, we aimed to investigate the anti-neuroinflammatory activities of MCC and determine the potential mechanisms underlying its action on lipopolysaccharide (LPS)-induced BV2 microglial cells. Our results revealed that MCC significantly reduced the secretion of nitric oxide (NO) and prostaglandin E2, concomitantly inhibiting the expression levels of inducible NO synthase and cyclooxygenase-2 mRNA and proteins. Additionally, MCC effectively decreased the production of reactive oxygen species in LPS-induced BV2 microglial cells. MCC also attenuates the activation of NF-κB by suppressing the phosphorylation of IκBα and NF-κB p65 subunits and by blocking the nuclear translocation of NF-κB p65 subunits. Furthermore, MCC significantly reduced the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β). In addition, MCC markedly increased the expression of heme oxygenase-1 (HO-1) by upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Collectively, our findings suggest that the anti-inflammatory activities of MCC could be attributed to its ability to suppress the activation of NF-κB, MAPK, and Akt/GSK-3β while enhancing that of Nrf2-mediated HO-1. Accordingly, MCC has promising therapeutic potential to treat neuroinflammation-related diseases. [Display omitted] • 4-Methoxycinnamyl p -coumarate (MCC) inhibited NO and PGE 2 in LPS-induced microglial cells. • MCC suppressed iNOS and COX-2 expression at mRNA and protein levels. • MCC suppressed the activation of NF-κB, MAPK, and Akt/GSK3ꞵ signaling pathways. • MCC alleviated the neuroinflammatory response by enhancing the Nrf2/HO-1 pathway. [ABSTRACT FROM AUTHOR]