Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently understood.As potent anti-i...Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently understood.As potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet known.In the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of action.In vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial polarization.Lipopolysaccharide,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were administered.RNA-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of dexamethasone.The Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our hypothesis.High-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain injury.Thus dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in vivo.Glucocorticoid receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain injury.Additionally,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is the GR/JAK1/STAT3 pathway.Overactivation of glucocorticoid receptor by high-dose dexamethasone reduced the expression of M2 microglia,which plays an antiinflammatory role.In contrast,inhibiting the activation of glucocorticoid receptor reduced the number of apoptotic glia and neurons and decreased the loss of dendritic spines after traumatic brain injury.Dexamethasone may exe rt its neurotoxic effects by inhibiting M2 microglia through the GR/JAK1/STAT3 signaling pathway.展开更多
Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Na...Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Nanoscale perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory properties.However,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly understood.In this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s disease.Microglial suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in vitro.Consequently,the neurotoxic effects were mitigated,which alleviated neuronal degeneration.Additionally,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic reprogramming.We further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1αpathway.Collectively,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.展开更多
Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which...Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.展开更多
Neuropathic pain(NP)is one of the most common pathological pain types and is associated with limited treatment options;moreover,it affects patients’quality of life and causes a heavy social burden.Despite the emphasi...Neuropathic pain(NP)is one of the most common pathological pain types and is associated with limited treatment options;moreover,it affects patients’quality of life and causes a heavy social burden.Despite the emphasis on inhibiting neuronal apoptosis to relieve NP,the crucial role of a neuroinflammation is often overlooked.Therefore,refocusing on the regulation of microglia polarization to create a more conducive environment for neuron holds great potential in NP treatment.In recent years,small interfering RNAs(siRNAs)had become an attractive therapeutic option.However,an efficient loading and delivery system for siRNA is still in lack.In our study,a nanostructured tetrahedral framework nucleic acid loaded with the small interfering RNA C–C chemokine receptor 2(T-siCCR2)was successfully designed and synthesized for use in NP rat model in vivo and in a lipopolysaccharide(LPS)-induced inflammatory environment in vitro.This nanoscale complex is endowed with structural stability and satisfactory delivery efficiency while assuring the silencing effect of siRNA-CCR2.In vivo,T-siCCR2 treatment exhibited favorable effects on pain relief and functional improvement in the NP animal model by directly targeting microglia.In vitro,T-siCCR2 counteracts LPS-induced inflammation by inhibiting the differentiation of microglia toward the M1 phenotype,thus playing a neuroprotective role.RNA sequencing was subsequently performed to elucidate the underlying mechanism involved.These results indicate that T-siCCR2 may serve as a potential treatment option for NP in the future.展开更多
Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease indu...Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.However,the effect of GLP-1 on intrinsic synuclein malfunction remains unclear.In this study,we investigated the effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism in SncaA53T transgenic mice and explored the underlying mechanisms.Our data showed that Lactococcus lactis MG1363-pMG36e-GLP-1 inhibited dopaminergic neuronal death,reduced pathological aggregation ofα-synuclein,and decreased movement disorders in SncaA53T transgenic mice.Furthermore,Lactococcus lactis MG1363-pMG36e-GLP-1 downregulated lipopolysaccharide-related inflammation,reduced cerebral activation of microglia and astrocytes,and promoted cell survival via the GLP-1 receptor/PI3K/Akt pathway in the substantia nigra.Additionally,Lactococcus lactis MG1363-pMG36e-GLP-1 decreased serum levels of pro-inflammatory molecules including lipopolysaccharide,lipopolysaccharide binding protein,interleukin-1β,and interleukin-6.Gut histopathology and western blotting further revealed that Lactococcus lactis MG1363-pMG36e-GLP-1 increased the expression of gut integrity-related proteins and reduced lipopolysaccharide-related inflammation by reversing gut dysbiosis in SncaA53T transgenic mice.Our findings showed that the beneficial effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism traits in SncaA53T transgenic mice is mediated by microglial polarization and the reversal of dysbiosis.Collectively,our findings suggest that Lactococcus lactis MG1363-pMG36e-GLP-1 is a promising therapeutic agent for the treatment of Parkinson’s disease.展开更多
Triggering receptor expressed on myeloid cells 2(TREM2)-mediated microglial phagocytosis is an energy-intensive process that plays a crucial role in amyloid beta(Aβ)clearance in Alzheimer’s disease(AD).Energy metabo...Triggering receptor expressed on myeloid cells 2(TREM2)-mediated microglial phagocytosis is an energy-intensive process that plays a crucial role in amyloid beta(Aβ)clearance in Alzheimer’s disease(AD).Energy metabolic reprogramming(EMR)in microglia induced by TREM2 presents therapeutic targets for cognitive impairment in AD.Jiawei Xionggui Decoction(JWXG)has demonstrated effectiveness in enhancing energy supply,protecting microglia,and mitigating cognitive impairment in APP/PS1 mice.However,the mechanism by which JWXG enhances Aβphagocytosis through TREM2-mediated EMR in microglia remains unclear.This study investigates how JWXG facilitates microglial phagocytosis and alleviates cognitive deficits in AD through TREM2-mediated EMR.Microglial phagocytosis was evaluated through immunofluorescence staining in vitro and in vivo.The EMR level of microglia was assessed using high-performance liquid chromatography(HPLC)and enzyme-linked immunosorbent assay(ELISA)kits.The TREM2/protein kinase B(Akt)/mammalian target of rapamycin(mTOR)/hypoxia-inducible factor-1α(HIF-1α)signaling pathway was analyzed using Western blotting in BV_(2) cells.TREM2^(−/−)BV_(2) cells were utilized for reverse validation experiments.The Aβburden,neuropathological features,and cognitive ability in APP/PS1 mice were evaluated using ELISA kits,immunohistochemistry(IHC),and the Morris water maze(MWM)test.JWXG enhanced both the phagocytosis of EMR disorder-BV_(2) cells(EMRD-BV_(2))and increased EMR levels.Notably,these effects were significantly reversed in TREM2^(−/−)BV_(2) cells.JWXG elevated TREM2 expression,adenosine triphosphate(ATP)levels,and microglial phagocytosis in APP/PS1 mice.Additionally,JWXG reduced Aβ-burden,neuropathological lesions,and cognitive deficits in APP/PS1 mice.In conclusion,JWXG promoted TREM2-induced EMR and enhanced microglial phagocytosis,thereby reducing Aβdeposition,improving neuropathological lesions,and alleviating cognitive deficits.展开更多
Background:Neuro-inflammation is regarded as one of the critical pathogenesis in neurodegenerative diseases,which is characterized by the activated microglial cells.Pectolinarin(Pec),a natural flavonoid that exists in...Background:Neuro-inflammation is regarded as one of the critical pathogenesis in neurodegenerative diseases,which is characterized by the activated microglial cells.Pectolinarin(Pec),a natural flavonoid that exists in many Chinese herbal medicines,has been reported to have various biological activities.However,the effects and mechanisms on neuro-inflammation are not clear.Methods:In this study,the inhibitory effects and mechanisms of Pec on neuro-inflammation were investigated in the LPS-stimulated microglial BV_(2) cells.BV_(2) microglial cells were treated with Pec or vehicle,followed by LPS.Enzyme-linked immunosorbent assay,real-time quantitative PCR,nitric oxide and reactive oxygen species assay,and western blot were performed to examine the effects of Pec on neuro-inflammatory responses.Results:We showed that Pec significantly inhibited the expression of tumor necrosis factorαand interleukin 6 in mRNA and protein levels induced by LPS.Moreover,the production of nitric oxide,iNOS,reactive oxygen species,and COX-2 were suppressed by Pec in LPS-stimulated microglial BV_(2) cells.In addition,Pec inhibited LPS-induced inflammation via nuclear factor kappa B signaling pathway,as evidenced by the reduction of the phosphorylation of inhibitor of nuclear factor kappa-B kinase,the degradation of IκBα,and the nuclear translocation of p65.Conclusion:Taken together,Pec exhibited anti-inflammatory effects in LPS-stimulated microglial BV_(2) cells via nuclear factor kappa B signaling pathway,which might provide therapeutic potential for neuro-inflammation and neurodegenerative diseases.展开更多
Microglia play multiple roles in such processes as brain development,homeostasis,and pathology.Due to their diverse mechanisms of functions,the complex sub-classifications,and the large differences between different s...Microglia play multiple roles in such processes as brain development,homeostasis,and pathology.Due to their diverse mechanisms of functions,the complex sub-classifications,and the large differences between different species,especially compared with humans,very different or even opposite conclusions can be drawn from studies with different research models.The choice of appropriate research models and the associated tools are thus key ingredients of studies on microglia.Mice are the most commonly used animal models.In this review,we summarize in vitro and in vivo models of mouse and human-derived microglial research models,including microglial cell lines,primary microglia,induced microglia-like cells,transgenic mice,human-mouse chimeric models,and microglial replacement models.We also summarize recent developments in novel single-cell and in vivo imaging technologies.We hope our review can serve as an efficient reference for the future study of microglia.展开更多
Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between neuronal autophag...Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between neuronal autophagy and microglial inflammation following ischemic stroke are poorly understood. CX3CL1/fractalkine, a membrane-bound chemokine expressed on neurons, can suppress microglial inflammation by binding to its receptor CX3CR1 on microglia. In the present study, to investigate whether autophagy could alter CX3CL1 expression on neurons and consequently change microglial inflammatory activity, middle cerebral artery occlusion(MCAO) was established in Sprague-Dawley rats to model ischemic stroke, and tissues from the ischemic penumbra were obtained to evaluate autophagy level and microglial inflammatory activity. MCAO rats were administered 3-methyladenine(autophagy inhibitor) or Tat-Beclin 1(autophagy inducer). Western blot assays were conducted to quantify expression of Beclin-1, nuclear factor kappa Bp65(NF-κB), light chain 3B(LC3B), and CX3CL1 in ischemic penumbra. Moreover, immunofluorescence staining was performed to quantify numbers of LC3B-, CX3CL1-, and Iba-1-positive cells in ischemic penumbra. In addition, enzyme linked immunosorbent assays were utilized to analyze concentrations of tumor necrosis factor alpha(TNF-α), interleukin 6(IL-6), interleukin 1 beta(IL-1β), and prostaglandin E2(PGE2). A dry/wet weight method was used to detect brain water content, while 2,3,5,-triphenyltetrazolium chloride staining was utilized to measure infarct volume. The results demonstrated that autophagy signaling(Beclin-1 and LC3B expression) in penumbra was prominently activated by MCAO, while CX3CL1 expression on autophagic neurons was significantly reduced and microglial inflammation was markedly activated. However, after inhibition of autophagy signaling with 3-methyladenine, CX3CL1 expression on neurons was obviously increased, whereas Iba-1 and NF-κB expression was downregulated; TNF-α, IL-6, IL-1β, and PGE2 levels were decreased; and cerebral edema was obviously mitigated. In contrast, after treatment with the autophagy inducer Tat-Beclin 1, CX3CL1 expression on neurons was further reduced; Iba-1 and NF-κB expression was increased; TNF-α, IL-6, IL-1β, and PGE2 levels were enhanced; and cerebral edema was aggravated. Our study suggests that ischemia-induced neuronal autophagy facilitates microglial inflammatory injury after ischemic stroke, and the efficacy of this process may be associated with downregulated CX3CL1 expression on autophagic neurons.展开更多
Inflammation plays important roles in the progress of neurodegenerative diseases,such as Parkinson’s disease and Alzheimer’s disease.Microglia is responsible for the homeostasis of the central nervous system(CNS),an...Inflammation plays important roles in the progress of neurodegenerative diseases,such as Parkinson’s disease and Alzheimer’s disease.Microglia is responsible for the homeostasis of the central nervous system(CNS),and involved in the neuroinflammation.Therefore,it could be potential in treatment of neurodegenerative diseases to suppress the microglia-mediated neuroinflammation.Mangiferin,a major glucoside of xanthone in Anemarrhena Rhizome,has anti-inflammatory,anti-diabetes,and anti-oxidative properties.However,the effect of mangiferin on the inflammatary responses of microglia cells are still poorly understand.In this study,we investigated the mechanism by which mangiferin inhibited inflammation in LPS-induced BV2 microglia cells.BV2 cells were pretreatment with mangiferin followed by LPS stimulation.In vitro assays,NO and cytokines production were quantified.Western blot and immunocytochemistry were used to examine the effect of mangiferin on the polarization of BV2 cells and signaling pathway.The results showed that mangiferin treatment significantly reduced NO,IL-1β,IL-6 and TNF-αproduction,also reduced the mRNA and protein of iNOS and COX-2,promoted the polarization of inflammatory toward anti-inflammatory,and inhibited activation of NF-κB and NLRP3 inflammasome.These data suggest that mangiferin has an anti-neuroinflammatory property via regulating microglia macrophage polarization and suppressing NF-κB and NLRP3 signaling pathway,and may act as a potential natural therapeutic candidate for neuroinflammatory diseases.展开更多
Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a gua...Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.展开更多
Interleukin-4 plays an important protective role in Alzheimer’s disease by regulating microglial phenotype,phagocytosis of amyloid-β,and secretion of anti-inflammatory and neurotrophic cytokines.Recently,increasing ...Interleukin-4 plays an important protective role in Alzheimer’s disease by regulating microglial phenotype,phagocytosis of amyloid-β,and secretion of anti-inflammatory and neurotrophic cytokines.Recently,increasing evidence has suggested that autophagy regulates innate immunity by affecting M1/M2 polarization of microglia/macrophages.However,the role of interleukin-4 in microglial autophagy is unknown.In view of this,BV2 microglia were treated with 0,10,20 or 50 ng/mL interleukin-4 for 24,48,or 72 hours.Subsequently,light chain 3-II and p62 protein expression levels were detected by western blot assay.BV2 microglia were incubated with interleukin-4(20 ng/mL,experimental group),3-methyladenine(500μM,autophagy inhibitor,negative control group),rapamycin(100 nM,autophagy inductor,positive control group),3-methyladenine+interleukin-4(rescue group),or without treatment for 24 hours,and then exposed to amyloid-β(1μM,model group)or vehicle control(control)for 24 hours.LC3-II and p62 protein expression levels were again detected by western blot assay.In addition,expression levels of multiple markers of M1 and M2 phenotype were assessed by real-time fluorescence quantitative polymerase chain reaction,while intracellular and supernatant amyloid-βprotein levels were measured by enzyme-linked immunosorbent assay.Our results showed that interleukin-4 induced microglial autophagic flux,most significantly at 20 ng/mL for 48 hours.Interleukin-4 pretreated microglia inhibited blockade of amyloid-β-induced autophagic flux,and promoted amyloid-βuptake and degradation partly through autophagic flux,but inhibited switching of amyloid-β-induced M1 phenotype independent on autophagic flux.These results indicate that interleukin-4 pretreated microglia increases uptake and degradation of amyloid-βin a process partly mediated by autophagy,which may play a protective role against Alzheimer’s disease.展开更多
Microglia are important cells involved in the regulation of neuropathic pain(NPP)and morphine tolerance.Information on their plasticity and polarity has been elucidated after determining their physiological structure,...Microglia are important cells involved in the regulation of neuropathic pain(NPP)and morphine tolerance.Information on their plasticity and polarity has been elucidated after determining their physiological structure,but there is still much to learn about the role of this type of cell in NPP and morphine tolerance.Microglia mediate multiple functions in health and disease by controlling damage in the central nervous system(CNS)and endogenous immune responses to disease.Microglial activation can result in altered opioid system activity,and NPP is characterized by resistance to morphine.Here we investigate the regulatory mechanisms of microglia and review the potential of microglial inhibitors for modulating NPP and morphine tolerance.Targeted inhibition of glial activation is a clinically promising approach to the treatment of NPP and the prevention of morphine tolerance.Finally,we suggest directions for future research on microglial inhibitors.展开更多
The treatment of microglial BV-2 cells with sodium arsenate（As（V）：0.1-400 μmol/L — 48 hr）induces a dose-dependent response.The neurotoxic effects of high concentrations of As（V）（100,200 and 400 μmol/L） are...The treatment of microglial BV-2 cells with sodium arsenate（As（V）：0.1-400 μmol/L — 48 hr）induces a dose-dependent response.The neurotoxic effects of high concentrations of As（V）（100,200 and 400 μmol/L） are characterized by increased levels of mitochondrial complexesⅠ,Ⅱ,and Ⅳ followed by increased superoxide anion generation.Moreover,As（V） triggers an apoptotic mode of cell death,demonstrated by an apoptotic SubG1 peak,associated with an alteration of plasma membrane integrity.There is also a decrease in transmembrane mitochondrial potential and mitochondrial adenosine triphosphate ATP.It is therefore tempting to speculate that As（V） triggers mitochondrial dysfunction,which may lead to defective oxidative phosphorylation subsequently causing mitochondrial oxidative damage,which in turn induces an apoptotic mode of cell death.展开更多
We have previously found that long-term effects of exposure to radiofrequency electromagnetic fields in 5xFAD mice with severe late-stage Alzheimer’s disease reduced both amyloid-βdeposition and glial activation,inc...We have previously found that long-term effects of exposure to radiofrequency electromagnetic fields in 5xFAD mice with severe late-stage Alzheimer’s disease reduced both amyloid-βdeposition and glial activation,including microglia.To examine whether this therapeutic effect is due to the regulation of activated microglia,we analyzed mic roglial gene expression profiles and the existence of microglia in the brain in this study.5xFAD mice at the age of 1.5 months were assigned to sham-and radiofrequency electromagnetic fields-exposed groups and then animals were exposed to 1950 MHz radiofrequency electromagnetic fields at a specific absorption rate of 5 W/kg for 2 hours/day and 5 days/week for 6 months.We conducted behavioral tests including the object recognition and Y-maze tests and molecular and histopathological analysis of amyloid precursor protein/a myloid-beta metabolism in brain tissue.We confirmed that radiofrequency electromagnetic field exposure for 6 months ameliorated cognitive impairment and amyloid-βdeposition.The expression levels of Iba1(pan-microglial marker)and colony-stimulating factor 1 receptor(CSF1R;regulates microglial prolife ration)in the hippocampus in 5xFAD mice treated with radiofrequency electromagnetic fields were significantly reduced compared with those of the sham-exposed group.Subsequently,we analyzed the expression levels of genes related to mic rogliosis and microglial function in the radiofrequency electromagnetic fields-exposed group compared to those of a CSF1R inhibitor(PLX3397)-treated group.Both radiofrequency electromagnetic fields and PLX3397 suppressed the levels of genes related to microgliosis(Csf1r,CD68,and Ccl6)and pro-inflammatory cytokine interleukin-1β.N otably,the expression levels of genes related to mic roglial function,including Trem2,Fcgr1α,Ctss,and Spi1,were decreased after long-term radiofrequency electromagnetic field exposure,which was also observed in response to microglial suppression by PLX3397.These results showed that radiofrequency electromagnetic fields ameliorated amyloid-βpathology and cognitive impairment by suppressing amyloid-βdeposition-induced microgliosis and their key regulator,CSF1R.展开更多
Microglial activation plays an important role in a panel of neurological disorders such as multiple sclerosis(MS) and Parkinson's disease(PD),and is a key target for developing therapeutic strategies for these dis...Microglial activation plays an important role in a panel of neurological disorders such as multiple sclerosis(MS) and Parkinson's disease(PD),and is a key target for developing therapeutic strategies for these diseases.Ketogenic diet (KD),which is able to inhibit microglial activation in substantia nigra pars compacta of mice,has been shown effective in a mouse model of PD,possibly through increasing D-β-hydroxybutyrate(D-β-HB),a major component of ketone bodies.To verify this,we developed an in vitro model of microglia activation with a microglia line,BV-2,and investigated how D-β-HB have an effect on the LPS-stimulated BV-2 cells.We found D-β-HB is able to recover the cell viability,and inhibit the production of inflammatory mediators and cytokines such as ROS,nitrite,IL-1β,TNF-α,and IL-6,which otherwise were increased in LPS-stimulated BV-2 cells.We conclude that the LPS induced BV-2 cells activation is a valid in vitro model of microglia activation.D-β-HB is able to suppress the activation of BV-2 cells, which might account for one of the possible reasons of KD therapy on the PD model.展开更多
Epilepsy is one of the most common neurological diseases worldwide with a high prevalence and unknown pathogenesis.Further,its control is challenging.It is generally accepted that an imbalance between the excitatory a...Epilepsy is one of the most common neurological diseases worldwide with a high prevalence and unknown pathogenesis.Further,its control is challenging.It is generally accepted that an imbalance between the excitatory and inhibitory properties of the central nervous system(CNS)leads to a large number of abnormally synchronized neuronal discharges in the brain.Transient receptor potential vanilloid protein type 1(TRPV1)is a non-selective cation channel that contributes to the regulation of the nervous system and influences the excitability of the nervous system.This includes the release of neurotransmitters,action potential generation due to alterations in ion channels,synaptic transmission,and the changes in glial cells.There is abundant evidence that TRPV1 is widely expressed in the central nervous system(including microglia)and is involved in the development of epilepsy through neuroinflammation.In conclusion,microglial TRPV1 participates in neuroinflammatory reactions and functions as a potential proinflammatory mediator.This presents a novel treatment approach to regulate seizures brought on by neuroinflammation.展开更多
Traumatic brain injury（TBI）remains one of the leading causes of disability and death in infants and children.Studies have demonstrated that the youngest age group（especially≤4 years old）exhibit worse functional o...Traumatic brain injury（TBI）remains one of the leading causes of disability and death in infants and children.Studies have demonstrated that the youngest age group（especially≤4 years old）exhibit worse functional outcome following moderate to severe TBI compared to older children or adults（Anderson et al.,2005;Emami et al.,2017）.These data suggest that age-at-injury may be an important determinant of outcome,展开更多
Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells wa...Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells was evaluated using a Cell Counting Kit-8(CCK-8)assay,and the effect of SYG concentrations on LPS-induced BV2 microglial cells was studied.The morphological changes were observed using an optical microscope.The nitric oxide(NO)concentration in cell culture supernatant was determined using Griess re-agent.The expression of cytokines and inflammatory mediators were also measured by an en-zyme-linked immunosorbent assay(ELISA).Western blot analysis was used to determine the levels of inducible NO synthase(iNOS),nuclear factor-kappa B(NF-κB)p65,alpha inhibitor of NF-κB(IκB-α),phosphorylation-IκB-α(p-IκB-α),NOD-like receptor 3(NLRP3),and cas-pase-1 expression.Moreover,the expression of iNOS,NLRP3,and ionized calcium binding adapter molecule 1(Iba1)was also observed using immunofluorescent staining.Results SYG had a low cytotoxic effect on BV2 microglial cells and could significantly decr-ease LPS-induced morphological changes of BV2 microglial cells(P<0.05).ELISA results showed that SYG significantly inhibited the LPS-induced increase in interleukin(IL)-1βand IL-6 in BV2 microglia cells(P<0.05),and Western blot analysis showed that the phosphoryla-tion levels of iNOS,NF-κB p65,and IκB-αas well as NLRP3 and caspase-1 expression were also significantly decreased,and IκB-αexpression was increased after SYG treatment(P<0.05,compared with the LPS-treated group).The immunofluorescence results were consist-ent with the Western blot results,and Iba1 staining indicated that the cell morphology tended to be resting.These results indicate that SYG has a certain inhibitory effect on LPS-induced inflammation in BV2 microglial cells.Conclusion SYG can inhibit LPS-induced release of inflammatory factors in BV2 microglial cells by affecting the phosphorylation levels of NF-κB p65 and IκB-α.SYG is a valuable candid-ate for treating neuroinflammation-related diseases.展开更多
Objective:To determine the anti-neuroinflammatory activity of Moringa oleifera leaf extract(MLE)under lipopolysaccharide stimulation of mouse murine microglia BV2 cells in vitro.Methods:The cytotoxicity effect of MLE ...Objective:To determine the anti-neuroinflammatory activity of Moringa oleifera leaf extract(MLE)under lipopolysaccharide stimulation of mouse murine microglia BV2 cells in vitro.Methods:The cytotoxicity effect of MLE was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay.The inflammatory response of BV-2 cells were induced with lipopolysaccharide.The generation of nitric oxide levels was determined by using Griess assay and the level of pro-inflammatory cytokines(IL-1β,IL-6 and TNF-α)was evaluated by ELISA kit.The expression of iNOS,COX-2 as well as IκB-ααwas carried out by immunoblot analysis.Results:MLE reduced the nitric oxide production in concentration-dependent manner,and maintained the viability of BV-2 microglial cells which indicated absence of toxicity.In addition,MLE repressed the activation of nuclear factor kappa B by arresting the deterioration of IκB-α,consequently resulted in suppression of cytokines expression such as COX-2 and iNOS.Conclusions:MLE inhibitory activities are associated with the inhibition of nuclear factor kappa B transcriptional activity in BV2 microglial cells.Thus MLE may offer a substantial treatment for neuroinflammatory diseases.展开更多
基金supported by research grants from the Ningbo Science and Technology Plan Project,No.2022Z143hezuo(to BL)the National Natural Science Foundation of China,No.82201520(to XD)。
文摘Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently understood.As potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet known.In the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of action.In vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial polarization.Lipopolysaccharide,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were administered.RNA-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of dexamethasone.The Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our hypothesis.High-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain injury.Thus dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in vivo.Glucocorticoid receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain injury.Additionally,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is the GR/JAK1/STAT3 pathway.Overactivation of glucocorticoid receptor by high-dose dexamethasone reduced the expression of M2 microglia,which plays an antiinflammatory role.In contrast,inhibiting the activation of glucocorticoid receptor reduced the number of apoptotic glia and neurons and decreased the loss of dendritic spines after traumatic brain injury.Dexamethasone may exe rt its neurotoxic effects by inhibiting M2 microglia through the GR/JAK1/STAT3 signaling pathway.
基金supported by the National Natural Science Foundation of China,No.82101327(to YY)President Foundation of Nanfang Hospital,Southern Medical University,No.2020A001(to WL)+1 种基金Guangdong Basic and Applied Basic Research Foundation,Nos.2019A1515110150,2022A1515012362(both to YY)Guangzhou Science and Technology Project,No.202201020111(to YY).
文摘Microglia,the primary immune cells within the brain,have gained recognition as a promising therapeutic target for managing neurodegenerative diseases within the central nervous system,including Parkinson’s disease.Nanoscale perfluorocarbon droplets have been reported to not only possess a high oxygen-carrying capacity,but also exhibit remarkable anti-inflammatory properties.However,the role of perfluoropentane in microglia-mediated central inflammatory reactions remains poorly understood.In this study,we developed perfluoropentane-based oxygen-loaded nanodroplets(PFP-OLNDs)and found that pretreatment with these droplets suppressed the lipopolysaccharide-induced activation of M1-type microglia in vitro and in vivo,and suppressed microglial activation in a mouse model of Parkinson’s disease.Microglial suppression led to a reduction in the inflammatory response,oxidative stress,and cell migration capacity in vitro.Consequently,the neurotoxic effects were mitigated,which alleviated neuronal degeneration.Additionally,ultrahigh-performance liquid chromatography–tandem mass spectrometry showed that the anti-inflammatory effects of PFP-OLNDs mainly resulted from the modulation of microglial metabolic reprogramming.We further showed that PFP-OLNDs regulated microglial metabolic reprogramming through the AKT-mTOR-HIF-1αpathway.Collectively,our findings suggest that the novel PFP-OLNDs constructed in this study alleviate microglia-mediated central inflammatory reactions through metabolic reprogramming.
基金supported by the National Natural Science Foundation of China(grant numbers 81371440,82271454 and 81971195).
文摘Objective Stroke is a main cause of disability and mortality worldwide.It has been reported that ischemic preconditioning(IP)has neuroprotective effects against stroke.This study aimed to verify the mechanism by which calcium-sensing recep-tor(Casr)inhibition-mediated M2 microglial transformation in the IP protects against stroke,which will provide a potential therapeutic target for stroke.Methods Middle cerebral artery occlusion(MCAO)rats and oxygen-glucose deprivation(OGD)neurons were used in this study.IP was induced via the transient MCAO and OGD methods.RNA sequencing(RNA-Seq)was used to explore the underlying key molecules.Western blotting and immunohistochemistry were performed to detect the expression of Casr and the M1 and M2 microglial markers.CCK8 was used to detect cell viability.The calcium concentration was detected via the use of Fluo-4 AM,a fluorescence probe.The Casr inhibitor NPS2143 and the Casr activator R568 were used to explore the role of Casr in M2 microglial transformation and neuroprotection.Results We first revealed that IP induced M2 microglial transformation in ischemic injury.In addition,MCAO injury increased Casr expression and the calcium concentration,which was inhibited by IP.Furthermore,Casr activation inhibited the M2 microglial transformation induced by IP.Finally,we found that Casr inhibition improved the survival rate,alleviated neurological deficits,and reduced the infarct volume induced by MCAO.Conclusions We confirmed that Casr-related neuroprotection induced by IP is associated with the transformation of M2 microglia.These findings can be used to understand the protective mechanisms of IP against ischemic stroke.
基金supported by National Natural Science Foundation of China(Nos.81874027,82370929,81970916)Sichuan Science and Technology Program(Nos.2019YFQ0003,2022YFS0051,2022NSFSC0002)+3 种基金Sichuan Province Youth Science and Technology Innovation Team(No.2022JDTD0021)Research and Develop Program,West China Hospital of Stomatology Sichuan University(Nos.RD03202302,RCDWJS2024–1)135-project for disciplines of excellenceClinical Research Incubation project of West China Hospital of Sichuan University(No.2021HXFH036)。
文摘Neuropathic pain(NP)is one of the most common pathological pain types and is associated with limited treatment options;moreover,it affects patients’quality of life and causes a heavy social burden.Despite the emphasis on inhibiting neuronal apoptosis to relieve NP,the crucial role of a neuroinflammation is often overlooked.Therefore,refocusing on the regulation of microglia polarization to create a more conducive environment for neuron holds great potential in NP treatment.In recent years,small interfering RNAs(siRNAs)had become an attractive therapeutic option.However,an efficient loading and delivery system for siRNA is still in lack.In our study,a nanostructured tetrahedral framework nucleic acid loaded with the small interfering RNA C–C chemokine receptor 2(T-siCCR2)was successfully designed and synthesized for use in NP rat model in vivo and in a lipopolysaccharide(LPS)-induced inflammatory environment in vitro.This nanoscale complex is endowed with structural stability and satisfactory delivery efficiency while assuring the silencing effect of siRNA-CCR2.In vivo,T-siCCR2 treatment exhibited favorable effects on pain relief and functional improvement in the NP animal model by directly targeting microglia.In vitro,T-siCCR2 counteracts LPS-induced inflammation by inhibiting the differentiation of microglia toward the M1 phenotype,thus playing a neuroprotective role.RNA sequencing was subsequently performed to elucidate the underlying mechanism involved.These results indicate that T-siCCR2 may serve as a potential treatment option for NP in the future.
基金supported by grants from the Jiangxi Provincial Natural Science Foundation,No.20242BAB26134(to XF)the National Natural Science Foundation of China,Nos.82060638(to TC),82060222(to XF),82460237(to XF)+1 种基金the Major Disciplines of Academic and Technical Leaders Project of Jiangxi Province,Nos.20194BCJ22032(to TC),20213BCJL22049(to XF)Science and Technology Plan of Jiangxi Health Planning Committee,No.202210390(to XF).
文摘Parkinson’s disease is characterized by synucleinopathy-associated neurodegeneration.Previous studies have shown that glucagon-like peptide-1(GLP-1)has beneficial effects in a mouse model of Parkinson’s disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.However,the effect of GLP-1 on intrinsic synuclein malfunction remains unclear.In this study,we investigated the effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism in SncaA53T transgenic mice and explored the underlying mechanisms.Our data showed that Lactococcus lactis MG1363-pMG36e-GLP-1 inhibited dopaminergic neuronal death,reduced pathological aggregation ofα-synuclein,and decreased movement disorders in SncaA53T transgenic mice.Furthermore,Lactococcus lactis MG1363-pMG36e-GLP-1 downregulated lipopolysaccharide-related inflammation,reduced cerebral activation of microglia and astrocytes,and promoted cell survival via the GLP-1 receptor/PI3K/Akt pathway in the substantia nigra.Additionally,Lactococcus lactis MG1363-pMG36e-GLP-1 decreased serum levels of pro-inflammatory molecules including lipopolysaccharide,lipopolysaccharide binding protein,interleukin-1β,and interleukin-6.Gut histopathology and western blotting further revealed that Lactococcus lactis MG1363-pMG36e-GLP-1 increased the expression of gut integrity-related proteins and reduced lipopolysaccharide-related inflammation by reversing gut dysbiosis in SncaA53T transgenic mice.Our findings showed that the beneficial effect of Lactococcus lactis MG1363-pMG36e-GLP-1 on parkinsonism traits in SncaA53T transgenic mice is mediated by microglial polarization and the reversal of dysbiosis.Collectively,our findings suggest that Lactococcus lactis MG1363-pMG36e-GLP-1 is a promising therapeutic agent for the treatment of Parkinson’s disease.
基金supported by the National Natural Science Foundation of China(Nos.82074150 and 82274240)the Natural Science Foundation of Sichuan Province(No.2023NSFSC1779).
文摘Triggering receptor expressed on myeloid cells 2(TREM2)-mediated microglial phagocytosis is an energy-intensive process that plays a crucial role in amyloid beta(Aβ)clearance in Alzheimer’s disease(AD).Energy metabolic reprogramming(EMR)in microglia induced by TREM2 presents therapeutic targets for cognitive impairment in AD.Jiawei Xionggui Decoction(JWXG)has demonstrated effectiveness in enhancing energy supply,protecting microglia,and mitigating cognitive impairment in APP/PS1 mice.However,the mechanism by which JWXG enhances Aβphagocytosis through TREM2-mediated EMR in microglia remains unclear.This study investigates how JWXG facilitates microglial phagocytosis and alleviates cognitive deficits in AD through TREM2-mediated EMR.Microglial phagocytosis was evaluated through immunofluorescence staining in vitro and in vivo.The EMR level of microglia was assessed using high-performance liquid chromatography(HPLC)and enzyme-linked immunosorbent assay(ELISA)kits.The TREM2/protein kinase B(Akt)/mammalian target of rapamycin(mTOR)/hypoxia-inducible factor-1α(HIF-1α)signaling pathway was analyzed using Western blotting in BV_(2) cells.TREM2^(−/−)BV_(2) cells were utilized for reverse validation experiments.The Aβburden,neuropathological features,and cognitive ability in APP/PS1 mice were evaluated using ELISA kits,immunohistochemistry(IHC),and the Morris water maze(MWM)test.JWXG enhanced both the phagocytosis of EMR disorder-BV_(2) cells(EMRD-BV_(2))and increased EMR levels.Notably,these effects were significantly reversed in TREM2^(−/−)BV_(2) cells.JWXG elevated TREM2 expression,adenosine triphosphate(ATP)levels,and microglial phagocytosis in APP/PS1 mice.Additionally,JWXG reduced Aβ-burden,neuropathological lesions,and cognitive deficits in APP/PS1 mice.In conclusion,JWXG promoted TREM2-induced EMR and enhanced microglial phagocytosis,thereby reducing Aβdeposition,improving neuropathological lesions,and alleviating cognitive deficits.
基金supported by the grants from the Training Program for Young Backbone Teachers in Colleges and Universities of Henan Province(2021GGJS103)the Program for Science and Technology Innovation Team in Universities of Henan Province(22IRTSTHN030)the Henan Neural Development Engineering Research Center for Children Foundation(SG201909).
文摘Background:Neuro-inflammation is regarded as one of the critical pathogenesis in neurodegenerative diseases,which is characterized by the activated microglial cells.Pectolinarin(Pec),a natural flavonoid that exists in many Chinese herbal medicines,has been reported to have various biological activities.However,the effects and mechanisms on neuro-inflammation are not clear.Methods:In this study,the inhibitory effects and mechanisms of Pec on neuro-inflammation were investigated in the LPS-stimulated microglial BV_(2) cells.BV_(2) microglial cells were treated with Pec or vehicle,followed by LPS.Enzyme-linked immunosorbent assay,real-time quantitative PCR,nitric oxide and reactive oxygen species assay,and western blot were performed to examine the effects of Pec on neuro-inflammatory responses.Results:We showed that Pec significantly inhibited the expression of tumor necrosis factorαand interleukin 6 in mRNA and protein levels induced by LPS.Moreover,the production of nitric oxide,iNOS,reactive oxygen species,and COX-2 were suppressed by Pec in LPS-stimulated microglial BV_(2) cells.In addition,Pec inhibited LPS-induced inflammation via nuclear factor kappa B signaling pathway,as evidenced by the reduction of the phosphorylation of inhibitor of nuclear factor kappa-B kinase,the degradation of IκBα,and the nuclear translocation of p65.Conclusion:Taken together,Pec exhibited anti-inflammatory effects in LPS-stimulated microglial BV_(2) cells via nuclear factor kappa B signaling pathway,which might provide therapeutic potential for neuro-inflammation and neurodegenerative diseases.
基金the National Key Research and Development Program of China(2017YFC0909200)the National Natural Science Foundation of China(81671336)+1 种基金Shanghai Key Laboratory of Psychotic Disorders(YG2016ZD06)the Shanghai Mental Health Center(2019-YJ06).
文摘Microglia play multiple roles in such processes as brain development,homeostasis,and pathology.Due to their diverse mechanisms of functions,the complex sub-classifications,and the large differences between different species,especially compared with humans,very different or even opposite conclusions can be drawn from studies with different research models.The choice of appropriate research models and the associated tools are thus key ingredients of studies on microglia.Mice are the most commonly used animal models.In this review,we summarize in vitro and in vivo models of mouse and human-derived microglial research models,including microglial cell lines,primary microglia,induced microglia-like cells,transgenic mice,human-mouse chimeric models,and microglial replacement models.We also summarize recent developments in novel single-cell and in vivo imaging technologies.We hope our review can serve as an efficient reference for the future study of microglia.
基金supported by the National Natural Science Foundation of China,No.81660383(to YHD),81860411(to HYH)a grant from the Applied Basic Research Projects of Yunnan Province of China,No.2017FB113(to YHD)the Scientific Research Fund of Yunnan Provincial Department of Education of China,No.2018JS016(to HYH)
文摘Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between neuronal autophagy and microglial inflammation following ischemic stroke are poorly understood. CX3CL1/fractalkine, a membrane-bound chemokine expressed on neurons, can suppress microglial inflammation by binding to its receptor CX3CR1 on microglia. In the present study, to investigate whether autophagy could alter CX3CL1 expression on neurons and consequently change microglial inflammatory activity, middle cerebral artery occlusion(MCAO) was established in Sprague-Dawley rats to model ischemic stroke, and tissues from the ischemic penumbra were obtained to evaluate autophagy level and microglial inflammatory activity. MCAO rats were administered 3-methyladenine(autophagy inhibitor) or Tat-Beclin 1(autophagy inducer). Western blot assays were conducted to quantify expression of Beclin-1, nuclear factor kappa Bp65(NF-κB), light chain 3B(LC3B), and CX3CL1 in ischemic penumbra. Moreover, immunofluorescence staining was performed to quantify numbers of LC3B-, CX3CL1-, and Iba-1-positive cells in ischemic penumbra. In addition, enzyme linked immunosorbent assays were utilized to analyze concentrations of tumor necrosis factor alpha(TNF-α), interleukin 6(IL-6), interleukin 1 beta(IL-1β), and prostaglandin E2(PGE2). A dry/wet weight method was used to detect brain water content, while 2,3,5,-triphenyltetrazolium chloride staining was utilized to measure infarct volume. The results demonstrated that autophagy signaling(Beclin-1 and LC3B expression) in penumbra was prominently activated by MCAO, while CX3CL1 expression on autophagic neurons was significantly reduced and microglial inflammation was markedly activated. However, after inhibition of autophagy signaling with 3-methyladenine, CX3CL1 expression on neurons was obviously increased, whereas Iba-1 and NF-κB expression was downregulated; TNF-α, IL-6, IL-1β, and PGE2 levels were decreased; and cerebral edema was obviously mitigated. In contrast, after treatment with the autophagy inducer Tat-Beclin 1, CX3CL1 expression on neurons was further reduced; Iba-1 and NF-κB expression was increased; TNF-α, IL-6, IL-1β, and PGE2 levels were enhanced; and cerebral edema was aggravated. Our study suggests that ischemia-induced neuronal autophagy facilitates microglial inflammatory injury after ischemic stroke, and the efficacy of this process may be associated with downregulated CX3CL1 expression on autophagic neurons.
基金the National Natural Science Foundation of China(No.81603357)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2017.Q8043)the Scientific Research Program Funded by Shaanxi Provincial Education Department(No.20JY011).
文摘Inflammation plays important roles in the progress of neurodegenerative diseases,such as Parkinson’s disease and Alzheimer’s disease.Microglia is responsible for the homeostasis of the central nervous system(CNS),and involved in the neuroinflammation.Therefore,it could be potential in treatment of neurodegenerative diseases to suppress the microglia-mediated neuroinflammation.Mangiferin,a major glucoside of xanthone in Anemarrhena Rhizome,has anti-inflammatory,anti-diabetes,and anti-oxidative properties.However,the effect of mangiferin on the inflammatary responses of microglia cells are still poorly understand.In this study,we investigated the mechanism by which mangiferin inhibited inflammation in LPS-induced BV2 microglia cells.BV2 cells were pretreatment with mangiferin followed by LPS stimulation.In vitro assays,NO and cytokines production were quantified.Western blot and immunocytochemistry were used to examine the effect of mangiferin on the polarization of BV2 cells and signaling pathway.The results showed that mangiferin treatment significantly reduced NO,IL-1β,IL-6 and TNF-αproduction,also reduced the mRNA and protein of iNOS and COX-2,promoted the polarization of inflammatory toward anti-inflammatory,and inhibited activation of NF-κB and NLRP3 inflammasome.These data suggest that mangiferin has an anti-neuroinflammatory property via regulating microglia macrophage polarization and suppressing NF-κB and NLRP3 signaling pathway,and may act as a potential natural therapeutic candidate for neuroinflammatory diseases.
基金Natural Science Foundation of Liaoning Province (General Program),No.2017010825 (to JQ)。
文摘Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.
基金supported by the Natural Science Foundation of Liaoning Province of China,No.20170541036(to HYL)
文摘Interleukin-4 plays an important protective role in Alzheimer’s disease by regulating microglial phenotype,phagocytosis of amyloid-β,and secretion of anti-inflammatory and neurotrophic cytokines.Recently,increasing evidence has suggested that autophagy regulates innate immunity by affecting M1/M2 polarization of microglia/macrophages.However,the role of interleukin-4 in microglial autophagy is unknown.In view of this,BV2 microglia were treated with 0,10,20 or 50 ng/mL interleukin-4 for 24,48,or 72 hours.Subsequently,light chain 3-II and p62 protein expression levels were detected by western blot assay.BV2 microglia were incubated with interleukin-4(20 ng/mL,experimental group),3-methyladenine(500μM,autophagy inhibitor,negative control group),rapamycin(100 nM,autophagy inductor,positive control group),3-methyladenine+interleukin-4(rescue group),or without treatment for 24 hours,and then exposed to amyloid-β(1μM,model group)or vehicle control(control)for 24 hours.LC3-II and p62 protein expression levels were again detected by western blot assay.In addition,expression levels of multiple markers of M1 and M2 phenotype were assessed by real-time fluorescence quantitative polymerase chain reaction,while intracellular and supernatant amyloid-βprotein levels were measured by enzyme-linked immunosorbent assay.Our results showed that interleukin-4 induced microglial autophagic flux,most significantly at 20 ng/mL for 48 hours.Interleukin-4 pretreated microglia inhibited blockade of amyloid-β-induced autophagic flux,and promoted amyloid-βuptake and degradation partly through autophagic flux,but inhibited switching of amyloid-β-induced M1 phenotype independent on autophagic flux.These results indicate that interleukin-4 pretreated microglia increases uptake and degradation of amyloid-βin a process partly mediated by autophagy,which may play a protective role against Alzheimer’s disease.
基金Project supported by the National Natural Science Foundation of China(No.81660199).
文摘Microglia are important cells involved in the regulation of neuropathic pain(NPP)and morphine tolerance.Information on their plasticity and polarity has been elucidated after determining their physiological structure,but there is still much to learn about the role of this type of cell in NPP and morphine tolerance.Microglia mediate multiple functions in health and disease by controlling damage in the central nervous system(CNS)and endogenous immune responses to disease.Microglial activation can result in altered opioid system activity,and NPP is characterized by resistance to morphine.Here we investigate the regulatory mechanisms of microglia and review the potential of microglial inhibitors for modulating NPP and morphine tolerance.Targeted inhibition of glial activation is a clinically promising approach to the treatment of NPP and the prevention of morphine tolerance.Finally,we suggest directions for future research on microglial inhibitors.
基金supported by grants from the University of Bourgogne(Dijon,France)the University of Monastir(Monastir,Tunisia)
文摘The treatment of microglial BV-2 cells with sodium arsenate（As（V）：0.1-400 μmol/L — 48 hr）induces a dose-dependent response.The neurotoxic effects of high concentrations of As（V）（100,200 and 400 μmol/L） are characterized by increased levels of mitochondrial complexesⅠ,Ⅱ,and Ⅳ followed by increased superoxide anion generation.Moreover,As（V） triggers an apoptotic mode of cell death,demonstrated by an apoptotic SubG1 peak,associated with an alteration of plasma membrane integrity.There is also a decrease in transmembrane mitochondrial potential and mitochondrial adenosine triphosphate ATP.It is therefore tempting to speculate that As（V） triggers mitochondrial dysfunction,which may lead to defective oxidative phosphorylation subsequently causing mitochondrial oxidative damage,which in turn induces an apoptotic mode of cell death.
基金Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by Korea government(MSIT),Nos.2017-0-00961 and 2019-0-00102(to HDC)。
文摘We have previously found that long-term effects of exposure to radiofrequency electromagnetic fields in 5xFAD mice with severe late-stage Alzheimer’s disease reduced both amyloid-βdeposition and glial activation,including microglia.To examine whether this therapeutic effect is due to the regulation of activated microglia,we analyzed mic roglial gene expression profiles and the existence of microglia in the brain in this study.5xFAD mice at the age of 1.5 months were assigned to sham-and radiofrequency electromagnetic fields-exposed groups and then animals were exposed to 1950 MHz radiofrequency electromagnetic fields at a specific absorption rate of 5 W/kg for 2 hours/day and 5 days/week for 6 months.We conducted behavioral tests including the object recognition and Y-maze tests and molecular and histopathological analysis of amyloid precursor protein/a myloid-beta metabolism in brain tissue.We confirmed that radiofrequency electromagnetic field exposure for 6 months ameliorated cognitive impairment and amyloid-βdeposition.The expression levels of Iba1(pan-microglial marker)and colony-stimulating factor 1 receptor(CSF1R;regulates microglial prolife ration)in the hippocampus in 5xFAD mice treated with radiofrequency electromagnetic fields were significantly reduced compared with those of the sham-exposed group.Subsequently,we analyzed the expression levels of genes related to mic rogliosis and microglial function in the radiofrequency electromagnetic fields-exposed group compared to those of a CSF1R inhibitor(PLX3397)-treated group.Both radiofrequency electromagnetic fields and PLX3397 suppressed the levels of genes related to microgliosis(Csf1r,CD68,and Ccl6)and pro-inflammatory cytokine interleukin-1β.N otably,the expression levels of genes related to mic roglial function,including Trem2,Fcgr1α,Ctss,and Spi1,were decreased after long-term radiofrequency electromagnetic field exposure,which was also observed in response to microglial suppression by PLX3397.These results showed that radiofrequency electromagnetic fields ameliorated amyloid-βpathology and cognitive impairment by suppressing amyloid-βdeposition-induced microgliosis and their key regulator,CSF1R.
文摘Microglial activation plays an important role in a panel of neurological disorders such as multiple sclerosis(MS) and Parkinson's disease(PD),and is a key target for developing therapeutic strategies for these diseases.Ketogenic diet (KD),which is able to inhibit microglial activation in substantia nigra pars compacta of mice,has been shown effective in a mouse model of PD,possibly through increasing D-β-hydroxybutyrate(D-β-HB),a major component of ketone bodies.To verify this,we developed an in vitro model of microglia activation with a microglia line,BV-2,and investigated how D-β-HB have an effect on the LPS-stimulated BV-2 cells.We found D-β-HB is able to recover the cell viability,and inhibit the production of inflammatory mediators and cytokines such as ROS,nitrite,IL-1β,TNF-α,and IL-6,which otherwise were increased in LPS-stimulated BV-2 cells.We conclude that the LPS induced BV-2 cells activation is a valid in vitro model of microglia activation.D-β-HB is able to suppress the activation of BV-2 cells, which might account for one of the possible reasons of KD therapy on the PD model.
文摘Epilepsy is one of the most common neurological diseases worldwide with a high prevalence and unknown pathogenesis.Further,its control is challenging.It is generally accepted that an imbalance between the excitatory and inhibitory properties of the central nervous system(CNS)leads to a large number of abnormally synchronized neuronal discharges in the brain.Transient receptor potential vanilloid protein type 1(TRPV1)is a non-selective cation channel that contributes to the regulation of the nervous system and influences the excitability of the nervous system.This includes the release of neurotransmitters,action potential generation due to alterations in ion channels,synaptic transmission,and the changes in glial cells.There is abundant evidence that TRPV1 is widely expressed in the central nervous system(including microglia)and is involved in the development of epilepsy through neuroinflammation.In conclusion,microglial TRPV1 participates in neuroinflammatory reactions and functions as a potential proinflammatory mediator.This presents a novel treatment approach to regulate seizures brought on by neuroinflammation.
文摘Traumatic brain injury（TBI）remains one of the leading causes of disability and death in infants and children.Studies have demonstrated that the youngest age group（especially≤4 years old）exhibit worse functional outcome following moderate to severe TBI compared to older children or adults（Anderson et al.,2005;Emami et al.,2017）.These data suggest that age-at-injury may be an important determinant of outcome,
基金The Space Medical Experiment Project of the China Manned Space Program(HYZHXM05003)National Natural Science Foundation of China(82171493)+2 种基金Natural Science Foundation of Hunan province(2021JJ30504)Scientific and Technological Innovation Project of the China Academy of Chinese Medical Sciences(CI2021A04905)Scientific Research Fund of Hunan Provincial Education of the Hunan University of Traditional Chinese Medicine First-class Discipline Project of Chinese Medicine(19B422)。
文摘Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells was evaluated using a Cell Counting Kit-8(CCK-8)assay,and the effect of SYG concentrations on LPS-induced BV2 microglial cells was studied.The morphological changes were observed using an optical microscope.The nitric oxide(NO)concentration in cell culture supernatant was determined using Griess re-agent.The expression of cytokines and inflammatory mediators were also measured by an en-zyme-linked immunosorbent assay(ELISA).Western blot analysis was used to determine the levels of inducible NO synthase(iNOS),nuclear factor-kappa B(NF-κB)p65,alpha inhibitor of NF-κB(IκB-α),phosphorylation-IκB-α(p-IκB-α),NOD-like receptor 3(NLRP3),and cas-pase-1 expression.Moreover,the expression of iNOS,NLRP3,and ionized calcium binding adapter molecule 1(Iba1)was also observed using immunofluorescent staining.Results SYG had a low cytotoxic effect on BV2 microglial cells and could significantly decr-ease LPS-induced morphological changes of BV2 microglial cells(P<0.05).ELISA results showed that SYG significantly inhibited the LPS-induced increase in interleukin(IL)-1βand IL-6 in BV2 microglia cells(P<0.05),and Western blot analysis showed that the phosphoryla-tion levels of iNOS,NF-κB p65,and IκB-αas well as NLRP3 and caspase-1 expression were also significantly decreased,and IκB-αexpression was increased after SYG treatment(P<0.05,compared with the LPS-treated group).The immunofluorescence results were consist-ent with the Western blot results,and Iba1 staining indicated that the cell morphology tended to be resting.These results indicate that SYG has a certain inhibitory effect on LPS-induced inflammation in BV2 microglial cells.Conclusion SYG can inhibit LPS-induced release of inflammatory factors in BV2 microglial cells by affecting the phosphorylation levels of NF-κB p65 and IκB-α.SYG is a valuable candid-ate for treating neuroinflammation-related diseases.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(NRF-2017R1C1B2010276 and 2017R1A2A2A07001035)
文摘Objective:To determine the anti-neuroinflammatory activity of Moringa oleifera leaf extract(MLE)under lipopolysaccharide stimulation of mouse murine microglia BV2 cells in vitro.Methods:The cytotoxicity effect of MLE was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay.The inflammatory response of BV-2 cells were induced with lipopolysaccharide.The generation of nitric oxide levels was determined by using Griess assay and the level of pro-inflammatory cytokines(IL-1β,IL-6 and TNF-α)was evaluated by ELISA kit.The expression of iNOS,COX-2 as well as IκB-ααwas carried out by immunoblot analysis.Results:MLE reduced the nitric oxide production in concentration-dependent manner,and maintained the viability of BV-2 microglial cells which indicated absence of toxicity.In addition,MLE repressed the activation of nuclear factor kappa B by arresting the deterioration of IκB-α,consequently resulted in suppression of cytokines expression such as COX-2 and iNOS.Conclusions:MLE inhibitory activities are associated with the inhibition of nuclear factor kappa B transcriptional activity in BV2 microglial cells.Thus MLE may offer a substantial treatment for neuroinflammatory diseases.
