Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological s...Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological stimuli.These functional states can be visualized using a combination of multi-omics techniques(e.g.,gene and protein expression,posttranslational modifications,mRNA profiling,and metabolomics),and,in the case of homeostatic microglia,are largely defined by the global(e.g.,genetic variations,organism’s age,sex,circadian rhythms,and gut microbiota)as well as local(specific area of the brain,immediate microglial surrounding,neuron-glia interactions and synaptic density/activity)signals(Paolicelli et al.,2022).While phenomics(i.e.,ultrastructural microglial morphology and motility)is also one of the key microglial state-defining parameters,it is known that cells with similar morphology can belong to different functional states.展开更多
Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a...Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.展开更多
Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microgl...Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.展开更多
Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in s...Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.展开更多
Inflammation plays a key role in driving the secondary brain injury that follows ischemic stroke.Melatonin is an endogenous neuroendocrine hormone that regulates mitochondrial homeostasis.However,the role and mechanis...Inflammation plays a key role in driving the secondary brain injury that follows ischemic stroke.Melatonin is an endogenous neuroendocrine hormone that regulates mitochondrial homeostasis.However,the role and mechanisms by which melatonin regulates microglial pyroptosis and the inflammatory cascade through double-stranded DNA(dsDNA)-sensing cyclic GMP-AMP synthase(cGAS)signaling warrant further study.Using middle cerebral artery occlusion mice,we investigated the effects of melatonin on cGAS-mediated pyroptosis and neuroinflammation.Middle cerebral artery occlusion model mice exhibited significantly increased DNA damage and cytoplasmic dsDNA release,as reflected byγH2AX staining,as well as heightened activation of the cytosolic dsDNA-sensing cGAS-STING pathway,both of which were notably suppressed by melatonin treatment.Melatonin also mitigated NOD-like receptor family pyrin domain-containing protein 3(NLRP3)inflammasome activation and nuclear factor(NF)-κB/gasdermin D-mediated pyroptosis in microglia following ischemic stroke,while exhibiting the capacity to attenuate the immune response to ischemia in mice.This led to reduced infiltration of peripheral neutrophils and monocytes/macrophages in the ischemic brain.Specifically,melatonin administration resulted in reductions in the numbers of ionized calcium-binding adapter molecule 1-positive cells and production of interleukin-6 and tumor necrosis factor-αby microglia.Regarding neurological outcomes,melatonin significantly reduced cerebral infarct volume and ameliorated neurological deficits in mice.Notably,the neuroprotective effect of melatonin was correlated with the inhibition of cGAS activity.We also developed and tested melatonin co-loaded macrophage membrane-biomimetic reactive oxygen species-responsive nanoparticles(Mф-MLT@FNGs),which exhibited therapeutic properties in middle cerebral artery occlusion mice.Our findings suggest that melatonin acts on microglial pyroptosis to inhibit neuroinflammation and reshape the immune microenvironment through regulation of the cGAS-STING-NF-κB signaling pathway.By doing so,melatonin rescues damaged brain tissue and protects neurological function,highlighting its potential as a neuroprotective treatment for ischemic stroke.展开更多
Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central n...Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central nervous system,microglia play a dual function in the progression of glaucoma.Under standard physiological states,microglia safeguard the retina by offering neurotrophic support and removing cellular debris.In the pathological progression of glaucoma,microglia become activated and release significant levels of inflammatory factors,resulting in retinal ganglion cell injury,cell death,and impaired neuroregeneration.This review focuses on examining the dual functions of microglia in glaucoma,evaluating their influence on retinal neurodegeneration and repair,and suggesting that modulating microglial activity could serve as a promising therapeutic strategy.Understanding the mechanisms of microglial action in glaucoma is crucial for unveiling the complex pathophysiological processes of the disease and developing new therapeutic strategies.展开更多
The cerebellum is receiving increasing attention for its cognitive,emotional,and social functions,as well as its unique metabolic profiles.Cerebellar microglia exhibit specialized and highly immunogenic phenotypes und...The cerebellum is receiving increasing attention for its cognitive,emotional,and social functions,as well as its unique metabolic profiles.Cerebellar microglia exhibit specialized and highly immunogenic phenotypes under both physiological and pathological conditions.These immune cells communicate with intrinsic and systemic factors and contribute to the structural and functional compartmentalization of the cerebellum.In this review,we discuss the roles of microglia in the cerebellar microenvironment,neuroinflammation,cerebellar adaptation,and neuronal activity,the associated molecular and cellular mechanisms,and potential therapeutic strategies targeting cerebellar microglia in the context of neuroinflammation.Future directions and unresolved questions in this field are further highlighted,particularly regarding therapeutic interventions targeting cerebellar microglia,functional mechanisms and activities of microglia in the cerebellar circuitry,neuronal connectivity,and neurofunctional outcomes of their activity.Cerebellar morphology and neuronal performance are influenced by both intrinsic and systemic factors that are actively monitored by microglia in both healthy and diseased states.Under pathological conditions,local subsets of microglia exhibit diverse responses to the altered microenvironment that contribute to the structural and functional compartmentalization of the cerebellum.Microglia in the cerebellum undergo early maturation during the embryonic stage and display specialized,highly immunogenic phenotypes.In summary,cerebellar microglia have the capacity to serve as regulatory tools that influence outcomes across a wide range of neurological and systemic conditions,including neurodevelopmental,neurodegenerative,metabolic,and stress-related disorders.展开更多
In recent years,rising life expectancy has led to a significant increase in the prevalence of neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease,and age-related cognitive decline.Addit...In recent years,rising life expectancy has led to a significant increase in the prevalence of neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease,and age-related cognitive decline.Additionally,other neurological conditions such as glioblastoma,the most common and aggressive brain tumor in adults have been more frequently reported in aging populations.The brain itself is highly vulnerable to age-related changes,particularly disruptions in homeostatic regulation,which further contribute to its functional decline and heightened susceptibility to disease.This has led to a surge of interest in understanding the cellular and molecular mechanisms driving these changes.展开更多
Microglia are the resident macrophages of the central nervous system.They act as the first line of defense against pathogens and play essential roles in neuroinflammation and tissue repair after brain insult or in neu...Microglia are the resident macrophages of the central nervous system.They act as the first line of defense against pathogens and play essential roles in neuroinflammation and tissue repair after brain insult or in neurodegenerative and demyelinating diseases(Borst et al.,2021).Together with infiltrating monocyte-derived macrophages,microglia also play a critical role for brain tumor development,since immunosuppressive interactions between tumor cells and tumor-associated microglia and macrophages(TAM)are linked to malignant progression.This mechanism is of particular relevance in glioblastoma(GB),the deadliest form of brain cancer with a median overall survival of less than 15 months(Khan et al.,2023).Therefore,targeting microglia and macrophage activation is a promising strategy for therapeutic interference in brain disease.展开更多
Chronic cerebral hypoperfusion can lead to neuronal necrosis,trigger inflammatory responses,promote white matter damage,and ultimately result in cognitive impairment.Consequently,chronic cerebral hypoperfusion is an i...Chronic cerebral hypoperfusion can lead to neuronal necrosis,trigger inflammatory responses,promote white matter damage,and ultimately result in cognitive impairment.Consequently,chronic cerebral hypoperfusion is an important factor influencing the onset and progression of vascular dementia.The myelin sheath is a critical component of white matter,and damage and repair of the white matter are closely linked to myelin sheath integrity.This article reviews the role of microglia in vascular dementia,focusing on their effects on myelin sheaths and the potential therapeutic implications.The findings suggest that ischemia and hypoxia cause disruption of the blood-brain barrier and activate microglia,which may worsen blood-brain barrier damage through the release of matrix-degrading enzymes.Microglia-mediated metabolic reprogramming is recognized as an important driver of inflammation.Damage to the blood-brain barrier and subsequent inflammation can lead to myelin injury and accelerate the progression of vascular dementia.Early activation of microglia is a protective response that contributes to the maintenance of blood-brain barrier integrity through sensing,debris-clearing,and defensive mechanisms.However,prolonged activation can trigger a shift in microglia toward the pro-inflammatory M1 phenotype,resulting in myelin damage and cognitive impairment.Triggering receptor expressed on myeloid cells 2 and triggering receptor expressed on myeloid cells 1 have been identified as potential biomarkers for vascular dementia,as both are closely linked to cognitive decline.Although effective clinical treatments for myelin damage in the central nervous system are currently lacking,researchers are actively working to develop targeted therapies.Several drugs,including nimodipine,dopaminergic agents,simvastatin,biotin,and quetiapine,have been evaluated for clinical use in treating microglial and myelin damage.Future research will face challenges in developing targeted therapeutic strategies for vascular dementia,requiring further investigation into the timing,duration,and specific mechanisms of microglial activation,as well as the exploration of new drug combinations and additional therapeutic targets.展开更多
For diverse neurodegenerative disorders,microglial cells are activated.Furthermore,dysfunctional and hyperactivated microglia initiate mitochondrial autophagy,oxidative stress,and pathological protein accumulation,end...For diverse neurodegenerative disorders,microglial cells are activated.Furthermore,dysfunctional and hyperactivated microglia initiate mitochondrial autophagy,oxidative stress,and pathological protein accumulation,ending with neuroinflammation that exacerbates damage to dopaminergic neurons and contributes significantly to the pathology of neurodegenerative disorder.Microglial overactivation is closely associated with the secretion of pro-inflammatory cytokines,the phagocytosis of injured neurons,and the modulation of neurotoxic environments.This review summarizes the role of microglia neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease,multiple sclerosis,multiple system atrophy,amyotrophic lateral sclerosis,frontotemporal dementia,progressive supranuclear palsy,cortical degeneration,Lewy body dementia,and Huntington's disease.It also discusses novel forms of cell death such as ferroptosis,cuproptosis,disulfidptosis,and parthanatos(poly(adenosine diphosphate ribose)polymerase 1-dependent cell death),as well as the impact of regulatory factors related to microglial inflammation on microglial activation and neuroinflammation.The aim is to identify potential targets for microglial cell therapy in neurodegenerative diseases.展开更多
In Alzheimer’s disease,microglial phagocytosis is engaged in the pathogenesis as it clears abnormal protein accumulations,debris,and apoptotic cells in the early stages of Alzheimer’s disease,but fuels neuroinflamma...In Alzheimer’s disease,microglial phagocytosis is engaged in the pathogenesis as it clears abnormal protein accumulations,debris,and apoptotic cells in the early stages of Alzheimer’s disease,but fuels neuroinflammation and accelerates disease progression in later stages.In vivo parabiosis experiments in aged animals have demonstrated that blood-born factors modulate synaptic plasticity,neurogenesis,and microglial responses.We hypothesize that peripheral factors can modulate microglial function and thereby possibly influence Alzheimer’s disease pathology.The objective of this study is to investigate the effects of Alzheimer’s disease serum on microglial phagocytosis.Here,we use an immortalized human microglial cell line in an in vitro parabiosis assay to investigate the impact of the serum from individuals diagnosed with Alzheimer’s disease(n=30)and age-matched controls(n=30)(PRODEM study)on microglial phagocytosis.Exposure to Alzheimer’s disease serum increased microglial phagocytic uptake of pH-sensitive fluorescent particles and downregulated expression of the lysosomal master regulator transcription factor EB(TFEB)and of ATPase H^(+)transporting lysosomal V1 subunit B2(ATP6V1B2),a component of the vacuolar ATPase.To identify serum components that may relate to changes in phagocytosis,serum samples of the Three-City Study(3C Study)were used.In the 3C Study,blood samples were collected up to 12 years before the onset of cognitive decline or dementia and their serum metabolome is well-defined.Microglia exposed to the serum of future Alzheimer’s disease patients from the 3C Study displayed an increased phagocytic uptake compared with the serum of matched controls,depending on the presence of the apolipoprotein Eε4 allele in the Alzheimer’s disease patients.Furthermore,microglial phagocytosis correlated inversely with serum levels of the omega-3 fatty acid eicosapentaenoic acid.We confirmed this inverse correlation between eicosapentaenoic acid and phagocytosis in the serum samples of the PRODEM cohort.In addition,in vitro testing of eicosapentaenoic acid on microglial phagocytosis showed a concentration-dependent decrease in phagocytic uptake.In conclusion,following incubation with Alzheimer’s disease blood serum,we observed increased microglial phagocytic uptake and the downregulation of TFEB and ATP6V1B2,possibly indicating lysosomal dysfunction.Furthermore,microglial phagocytosis was inversely correlated with serum eicosapentaenoic acid levels,suggesting an important role for dietary eicosapentaenoic acid in microglial function.展开更多
Germinal matrix hemorrhage in preterm neonates often leads to white matter injury,contributing to long-term neurodevelopmental impairments.As resident brain immune cells,microglia play a complex role in injury respons...Germinal matrix hemorrhage in preterm neonates often leads to white matter injury,contributing to long-term neurodevelopmental impairments.As resident brain immune cells,microglia play a complex role in injury response,including inflammation and repair.Although colony-stimulating factor 1 receptor inhibitors such as PLX5622 enable the selective depletion of microglia,their therapeutic potential in neonatal germinal matrix hemorrhage remains underexplored.Here,we used a collagenase-induced germinal matrix hemorrhage model in postnatal day 5 mice,and intraperitoneally administered PLX562272 hours post-germinal matrix hemorrhage to achieve targeted,temporary microglial depletion during the peak injury response.We then assessed the effects of this delayed intervention on oligodendrocyte lineage cell maturation,white matter integrity,and neurobehavioral outcomes.Additionally,RNA sequencing data from a germinal matrix hemorrhage rat model were analyzed using weighted gene co-expression network analysis to identify the critical phases for interventions.RNA sequencing data revealed a critical period in which key synaptic functions declined while immune responses intensified post-germinal matrix hemorrhage,thus pinpointing the critical response phases for potential interventions.Delayed PLX5622 treatment effectively depleted activated microglia,protecting against white matter injury and enhancing oligodendrocyte lineage cell maturation and myelination in subcortical white matter regions.Moreover,magnetic resonance imaging analysis revealed reduced brain lesion volumes in treated mice.Behaviorally,PLX5622-treated mice exhibited significant improvements in motor coordination and reduced hyperactivity compared with vehicle-treated germinal matrix hemorrhage model mice.These findings suggest that,when timed to avoid interference with initial oligodendrocyte lineage cell proliferation,targeted microglial depletion with PLX5622 significantly mitigates white matter damage and improves neurobehavioral outcomes in neonatal germinal matrix hemorrhage.The present study highlights the therapeutic potential of selectively modulating microglial reactivity to support neurodevelopment in preterm infants with brain injury.展开更多
Early life stress correlates with a higher prevalence of neurological disorders,including autism,attention-deficit/hyperactivity disorder,schizophrenia,depression,and Parkinson's disease.These conditions,primarily...Early life stress correlates with a higher prevalence of neurological disorders,including autism,attention-deficit/hyperactivity disorder,schizophrenia,depression,and Parkinson's disease.These conditions,primarily involving abnormal development and damage of the dopaminergic system,pose significant public health challenges.Microglia,as the primary immune cells in the brain,are crucial in regulating neuronal circuit development and survival.From the embryonic stage to adulthood,microglia exhibit stage-specific gene expression profiles,transcriptome characteristics,and functional phenotypes,enhancing the susceptibility to early life stress.However,the role of microglia in mediating dopaminergic system disorders under early life stress conditions remains poorly understood.This review presents an up-to-date overview of preclinical studies elucidating the impact of early life stress on microglia,leading to dopaminergic system disorders,along with the underlying mechanisms and therapeutic potential for neurodegenerative and neurodevelopmental conditions.Impaired microglial activity damages dopaminergic neurons by diminishing neurotrophic support(e.g.,insulin-like growth factor-1)and hinders dopaminergic axon growth through defective phagocytosis and synaptic pruning.Furthermore,blunted microglial immunoreactivity suppresses striatal dopaminergic circuit development and reduces neuronal transmission.Furthermore,inflammation and oxidative stress induced by activated microglia can directly damage dopaminergic neurons,inhibiting dopamine synthesis,reuptake,and receptor activity.Enhanced microglial phagocytosis inhibits dopamine axon extension.These long-lasting effects of microglial perturbations may be driven by early life stress–induced epigenetic reprogramming of microglia.Indirectly,early life stress may influence microglial function through various pathways,such as astrocytic activation,the hypothalamic–pituitary–adrenal axis,the gut–brain axis,and maternal immune signaling.Finally,various therapeutic strategies and molecular mechanisms for targeting microglia to restore the dopaminergic system were summarized and discussed.These strategies include classical antidepressants and antipsychotics,antibiotics and anti-inflammatory agents,and herbal-derived medicine.Further investigations combining pharmacological interventions and genetic strategies are essential to elucidate the causal role of microglial phenotypic and functional perturbations in the dopaminergic system disrupted by early life stress.展开更多
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
The primary mechanism of secondary injury after cerebral ischemia may be the brain inflammation that emerges after an ischemic stroke,which promotes neuronal death and inhibits nerve tissue regeneration.As the first i...The primary mechanism of secondary injury after cerebral ischemia may be the brain inflammation that emerges after an ischemic stroke,which promotes neuronal death and inhibits nerve tissue regeneration.As the first immune cells to be activated after an ischemic stroke,microglia play an important immunomodulatory role in the progression of the condition.After an ischemic stroke,peripheral blood immune cells(mainly T cells)are recruited to the central nervous system by chemokines secreted by immune cells in the brain,where they interact with central nervous system cells(mainly microglia)to trigger a secondary neuroimmune response.This review summarizes the interactions between T cells and microglia in the immune-inflammatory processes of ischemic stroke.We found that,during ischemic stroke,T cells and microglia demonstrate a more pronounced synergistic effect.Th1,Th17,and M1 microglia can co-secrete proinflammatory factors,such as interferon-γ,tumor necrosis factor-α,and interleukin-1β,to promote neuroinflammation and exacerbate brain injury.Th2,Treg,and M2 microglia jointly secrete anti-inflammatory factors,such as interleukin-4,interleukin-10,and transforming growth factor-β,to inhibit the progression of neuroinflammation,as well as growth factors such as brain-derived neurotrophic factor to promote nerve regeneration and repair brain injury.Immune interactions between microglia and T cells influence the direction of the subsequent neuroinflammation,which in turn determines the prognosis of ischemic stroke patients.Clinical trials have been conducted on the ways to modulate the interactions between T cells and microglia toward anti-inflammatory communication using the immunosuppressant fingolimod or overdosing with Treg cells to promote neural tissue repair and reduce the damage caused by ischemic stroke.However,such studies have been relatively infrequent,and clinical experience is still insufficient.In summary,in ischemic stroke,T cell subsets and activated microglia act synergistically to regulate inflammatory progression,mainly by secreting inflammatory factors.In the future,a key research direction for ischemic stroke treatment could be rooted in the enhancement of anti-inflammatory factor secretion by promoting the generation of Th2 and Treg cells,along with the activation of M2-type microglia.These approaches may alleviate neuroinflammation and facilitate the repair of neural tissues.展开更多
Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells...Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.展开更多
The development of neurodegenerative diseases is closely related to the disruption of central nervous system homeostasis.Microglia,as innate immune cells,play important roles in the maintenance of central nervous syst...The development of neurodegenerative diseases is closely related to the disruption of central nervous system homeostasis.Microglia,as innate immune cells,play important roles in the maintenance of central nervous system homeostasis,injury response,and neurodegenerative diseases.Lactate has been considered a metabolic waste product,but recent studies are revealing ever more of the physiological functions of lactate.Lactylation is an important pathway in lactate function and is involved in glycolysis-related functions,macrophage polarization,neuromodulation,and angiogenesis and has also been implicated in the development of various diseases.This review provides an overview of the lactate metabolic and homeostatic regulatory processes involved in microglia lactylation,histone versus non-histone lactylation,and therapeutic approaches targeting lactate.Finally,we summarize the current research on microglia lactylation in central nervous system diseases.A deeper understanding of the metabolic regulatory mechanisms of microglia lactylation will provide more options for the treatment of central nervous system diseases.展开更多
The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia ...The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia polarization from M1(neurotoxic and proinflammatory type)to M2(neuroprotective and anti-inflammatory type)after spinal cord injury appears to be crucial.Tryptanthrin possesses an anti-inflammatory biological function.However,its roles and the underlying molecular mechanisms in spinal cord injury remain unknown.In this study,we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro.Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway.Additionally,we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury,inhibited neuronal loss,and promoted tissue repair and functional recovery in a mouse model of spinal cord injury.Finally,using a conditional co-culture system,we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis.Taken together,these results suggest that by targeting the cGAS/STING/NF-κB axis,tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype.展开更多
基金supported by Deutsche Forschungsgemeinschaft,German Research Foundation grant GA 654/13-2 to OG.
文摘Microglia,the resident immune cells of the central nervous system,exhibit a wide array of functional states,even in their so-called“homeostatic”condition,when they are not actively responding to overt pathological stimuli.These functional states can be visualized using a combination of multi-omics techniques(e.g.,gene and protein expression,posttranslational modifications,mRNA profiling,and metabolomics),and,in the case of homeostatic microglia,are largely defined by the global(e.g.,genetic variations,organism’s age,sex,circadian rhythms,and gut microbiota)as well as local(specific area of the brain,immediate microglial surrounding,neuron-glia interactions and synaptic density/activity)signals(Paolicelli et al.,2022).While phenomics(i.e.,ultrastructural microglial morphology and motility)is also one of the key microglial state-defining parameters,it is known that cells with similar morphology can belong to different functional states.
基金supported by the National Natural Science Foundation of China,82471345(to LC)the Key Research and Development Program for Social Development by the Jiangsu Provincial Department of Science and Technology.No.BE2022668(to LC).
文摘Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.
基金supported by the Natural Science Foundation of Yunnan Province,No.202401AS070086(to ZW)the National Key Research and Development Program of China,No.2018YFA0801403(to ZW)+1 种基金Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(to ZW)the Natural Science Foundation of China,No.31960120(to ZW)。
文摘Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.
基金supported by the National Natural Science Foundation of China,Nos.82072165 and 82272256(both to XM)the Key Project of Xiangyang Central Hospital,No.2023YZ03(to RM)。
文摘Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.
基金supported by the Natural Science Foundation of Heilongjiang Province,No.YQ2021H011(to QL)China Postdoctoral Science Foundation,Nos.2020M670925,2022T150172(to QL)+2 种基金Postdoctoral Foundation of Heilongjiang Province,Nos.LBH‐Z19027,LBH‐TZ2019(to QL)Institute Cultivation Fund,No.PYMS2023-1(to QL)Natural Science Foundation of Jiangsu Province,No.BK20241233(to YL).
文摘Inflammation plays a key role in driving the secondary brain injury that follows ischemic stroke.Melatonin is an endogenous neuroendocrine hormone that regulates mitochondrial homeostasis.However,the role and mechanisms by which melatonin regulates microglial pyroptosis and the inflammatory cascade through double-stranded DNA(dsDNA)-sensing cyclic GMP-AMP synthase(cGAS)signaling warrant further study.Using middle cerebral artery occlusion mice,we investigated the effects of melatonin on cGAS-mediated pyroptosis and neuroinflammation.Middle cerebral artery occlusion model mice exhibited significantly increased DNA damage and cytoplasmic dsDNA release,as reflected byγH2AX staining,as well as heightened activation of the cytosolic dsDNA-sensing cGAS-STING pathway,both of which were notably suppressed by melatonin treatment.Melatonin also mitigated NOD-like receptor family pyrin domain-containing protein 3(NLRP3)inflammasome activation and nuclear factor(NF)-κB/gasdermin D-mediated pyroptosis in microglia following ischemic stroke,while exhibiting the capacity to attenuate the immune response to ischemia in mice.This led to reduced infiltration of peripheral neutrophils and monocytes/macrophages in the ischemic brain.Specifically,melatonin administration resulted in reductions in the numbers of ionized calcium-binding adapter molecule 1-positive cells and production of interleukin-6 and tumor necrosis factor-αby microglia.Regarding neurological outcomes,melatonin significantly reduced cerebral infarct volume and ameliorated neurological deficits in mice.Notably,the neuroprotective effect of melatonin was correlated with the inhibition of cGAS activity.We also developed and tested melatonin co-loaded macrophage membrane-biomimetic reactive oxygen species-responsive nanoparticles(Mф-MLT@FNGs),which exhibited therapeutic properties in middle cerebral artery occlusion mice.Our findings suggest that melatonin acts on microglial pyroptosis to inhibit neuroinflammation and reshape the immune microenvironment through regulation of the cGAS-STING-NF-κB signaling pathway.By doing so,melatonin rescues damaged brain tissue and protects neurological function,highlighting its potential as a neuroprotective treatment for ischemic stroke.
基金supported by the Deutsche Forschungsgemeinschaft(DFG)with grants PR1569/1-1 and PR 1569/1-3(to VP).
文摘Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central nervous system,microglia play a dual function in the progression of glaucoma.Under standard physiological states,microglia safeguard the retina by offering neurotrophic support and removing cellular debris.In the pathological progression of glaucoma,microglia become activated and release significant levels of inflammatory factors,resulting in retinal ganglion cell injury,cell death,and impaired neuroregeneration.This review focuses on examining the dual functions of microglia in glaucoma,evaluating their influence on retinal neurodegeneration and repair,and suggesting that modulating microglial activity could serve as a promising therapeutic strategy.Understanding the mechanisms of microglial action in glaucoma is crucial for unveiling the complex pathophysiological processes of the disease and developing new therapeutic strategies.
基金supported by grants from STI2030-Major Projects,No.2021ZD0204000(to YS)Key Strategic Science and Technology Cooperation Project of the Ministry of Science and Technology of China,No.SQ2023YFE0201430(to YS)+1 种基金the National Natural Science Foundation of China,Nos.31820103005(to YS),32200620(to LW)the Natural Science Foundation of Zhejiang Province of China,No.LZ24C090003(to YS)。
文摘The cerebellum is receiving increasing attention for its cognitive,emotional,and social functions,as well as its unique metabolic profiles.Cerebellar microglia exhibit specialized and highly immunogenic phenotypes under both physiological and pathological conditions.These immune cells communicate with intrinsic and systemic factors and contribute to the structural and functional compartmentalization of the cerebellum.In this review,we discuss the roles of microglia in the cerebellar microenvironment,neuroinflammation,cerebellar adaptation,and neuronal activity,the associated molecular and cellular mechanisms,and potential therapeutic strategies targeting cerebellar microglia in the context of neuroinflammation.Future directions and unresolved questions in this field are further highlighted,particularly regarding therapeutic interventions targeting cerebellar microglia,functional mechanisms and activities of microglia in the cerebellar circuitry,neuronal connectivity,and neurofunctional outcomes of their activity.Cerebellar morphology and neuronal performance are influenced by both intrinsic and systemic factors that are actively monitored by microglia in both healthy and diseased states.Under pathological conditions,local subsets of microglia exhibit diverse responses to the altered microenvironment that contribute to the structural and functional compartmentalization of the cerebellum.Microglia in the cerebellum undergo early maturation during the embryonic stage and display specialized,highly immunogenic phenotypes.In summary,cerebellar microglia have the capacity to serve as regulatory tools that influence outcomes across a wide range of neurological and systemic conditions,including neurodevelopmental,neurodegenerative,metabolic,and stress-related disorders.
基金supported by the Swedish ResearchCouncil and the Swedish Brain Foundation,theCancer Research Funds of Radiumhemmet,theStrategic Research Area in Cancer(StratCan),the Strategic Research Area in Neuroscience(StratNeuro),the Swedish Cancer Society,theSwedish Childhood Cancer Foundation,theKarolinska Institutet Foundation,the InnoHKinitiative of the Innovation and TechnologyCommission of the Hong Kong SpecialAdministrative Region Government(to BJ).Openaccess funding is provided by the KarolinskaInstitute.
文摘In recent years,rising life expectancy has led to a significant increase in the prevalence of neurodegenerative disorders,including Alzheimer’s disease(AD),Parkinson’s disease,and age-related cognitive decline.Additionally,other neurological conditions such as glioblastoma,the most common and aggressive brain tumor in adults have been more frequently reported in aging populations.The brain itself is highly vulnerable to age-related changes,particularly disruptions in homeostatic regulation,which further contribute to its functional decline and heightened susceptibility to disease.This has led to a surge of interest in understanding the cellular and molecular mechanisms driving these changes.
基金Deutsche Forschungsgemeinschaft(DFG,German Research Foundation),project numbers 324633948 and 409784463(DFG grants Hi 678/9-3 and Hi 678/10-2,FOR2953)to HHBundesministerium für Bildung und Forschung-BMBF,project number 16LW0463K to HT.
文摘Microglia are the resident macrophages of the central nervous system.They act as the first line of defense against pathogens and play essential roles in neuroinflammation and tissue repair after brain insult or in neurodegenerative and demyelinating diseases(Borst et al.,2021).Together with infiltrating monocyte-derived macrophages,microglia also play a critical role for brain tumor development,since immunosuppressive interactions between tumor cells and tumor-associated microglia and macrophages(TAM)are linked to malignant progression.This mechanism is of particular relevance in glioblastoma(GB),the deadliest form of brain cancer with a median overall survival of less than 15 months(Khan et al.,2023).Therefore,targeting microglia and macrophage activation is a promising strategy for therapeutic interference in brain disease.
基金supported by the Natural Science Foundation of Beijing,No.7232279(to XW)the National Natural Science Foundation of China,No.U21A20400(to QW)Key Project of Beijing University of Chinese Medicine,Nos.2022-JYB-JBZR-004(to XW),2024-JYB-JBZD-043(to CL).
文摘Chronic cerebral hypoperfusion can lead to neuronal necrosis,trigger inflammatory responses,promote white matter damage,and ultimately result in cognitive impairment.Consequently,chronic cerebral hypoperfusion is an important factor influencing the onset and progression of vascular dementia.The myelin sheath is a critical component of white matter,and damage and repair of the white matter are closely linked to myelin sheath integrity.This article reviews the role of microglia in vascular dementia,focusing on their effects on myelin sheaths and the potential therapeutic implications.The findings suggest that ischemia and hypoxia cause disruption of the blood-brain barrier and activate microglia,which may worsen blood-brain barrier damage through the release of matrix-degrading enzymes.Microglia-mediated metabolic reprogramming is recognized as an important driver of inflammation.Damage to the blood-brain barrier and subsequent inflammation can lead to myelin injury and accelerate the progression of vascular dementia.Early activation of microglia is a protective response that contributes to the maintenance of blood-brain barrier integrity through sensing,debris-clearing,and defensive mechanisms.However,prolonged activation can trigger a shift in microglia toward the pro-inflammatory M1 phenotype,resulting in myelin damage and cognitive impairment.Triggering receptor expressed on myeloid cells 2 and triggering receptor expressed on myeloid cells 1 have been identified as potential biomarkers for vascular dementia,as both are closely linked to cognitive decline.Although effective clinical treatments for myelin damage in the central nervous system are currently lacking,researchers are actively working to develop targeted therapies.Several drugs,including nimodipine,dopaminergic agents,simvastatin,biotin,and quetiapine,have been evaluated for clinical use in treating microglial and myelin damage.Future research will face challenges in developing targeted therapeutic strategies for vascular dementia,requiring further investigation into the timing,duration,and specific mechanisms of microglial activation,as well as the exploration of new drug combinations and additional therapeutic targets.
基金funded by the Science and Technology Research of Henan Province,No.242103810041(to JY)。
文摘For diverse neurodegenerative disorders,microglial cells are activated.Furthermore,dysfunctional and hyperactivated microglia initiate mitochondrial autophagy,oxidative stress,and pathological protein accumulation,ending with neuroinflammation that exacerbates damage to dopaminergic neurons and contributes significantly to the pathology of neurodegenerative disorder.Microglial overactivation is closely associated with the secretion of pro-inflammatory cytokines,the phagocytosis of injured neurons,and the modulation of neurotoxic environments.This review summarizes the role of microglia neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease,multiple sclerosis,multiple system atrophy,amyotrophic lateral sclerosis,frontotemporal dementia,progressive supranuclear palsy,cortical degeneration,Lewy body dementia,and Huntington's disease.It also discusses novel forms of cell death such as ferroptosis,cuproptosis,disulfidptosis,and parthanatos(poly(adenosine diphosphate ribose)polymerase 1-dependent cell death),as well as the impact of regulatory factors related to microglial inflammation on microglial activation and neuroinflammation.The aim is to identify potential targets for microglial cell therapy in neurodegenerative diseases.
基金part of the EU consortium DCog Plast ‘Diet Cognition and Plasticity” funded by the Joint Programming Initiative “A Health Diet for a Healthy Life”(JPI-HDHL) via the BMWFW (BMWFW-10.420/0009-WF/V/3c/2015 and the Medical Research Council UK:MR/N030087/1)(to LA and ST)supported by the PMU-FFF Research Fund (A-16/01/019-AIG)+9 种基金BA by the PMU-Research and Innovation Fund (PMU-RIF)(project 2023-PRE-008-Altendorfer)supported by the Center for Urban Mental Healthby Alzheimer Nederlandthe Zon MW Program Mechanisms Of DEMentia (MODEM)by the Gravitation program iCNS of the Dutch Research Council (NWO)supported by Grant PID2020-114921RB-C21Maria de Maeztu Unit of Excellence grant CEX2021-001234-M funded by MCIU/AEI/and CIBERFESCB16/10/00269, from the Instituto de Salud Carlos III all of them by “ERDF A way of making Europe”the Generalitat de Catalunya’s Agency AGAUR of 2021SGR00687ICREA Award
文摘In Alzheimer’s disease,microglial phagocytosis is engaged in the pathogenesis as it clears abnormal protein accumulations,debris,and apoptotic cells in the early stages of Alzheimer’s disease,but fuels neuroinflammation and accelerates disease progression in later stages.In vivo parabiosis experiments in aged animals have demonstrated that blood-born factors modulate synaptic plasticity,neurogenesis,and microglial responses.We hypothesize that peripheral factors can modulate microglial function and thereby possibly influence Alzheimer’s disease pathology.The objective of this study is to investigate the effects of Alzheimer’s disease serum on microglial phagocytosis.Here,we use an immortalized human microglial cell line in an in vitro parabiosis assay to investigate the impact of the serum from individuals diagnosed with Alzheimer’s disease(n=30)and age-matched controls(n=30)(PRODEM study)on microglial phagocytosis.Exposure to Alzheimer’s disease serum increased microglial phagocytic uptake of pH-sensitive fluorescent particles and downregulated expression of the lysosomal master regulator transcription factor EB(TFEB)and of ATPase H^(+)transporting lysosomal V1 subunit B2(ATP6V1B2),a component of the vacuolar ATPase.To identify serum components that may relate to changes in phagocytosis,serum samples of the Three-City Study(3C Study)were used.In the 3C Study,blood samples were collected up to 12 years before the onset of cognitive decline or dementia and their serum metabolome is well-defined.Microglia exposed to the serum of future Alzheimer’s disease patients from the 3C Study displayed an increased phagocytic uptake compared with the serum of matched controls,depending on the presence of the apolipoprotein Eε4 allele in the Alzheimer’s disease patients.Furthermore,microglial phagocytosis correlated inversely with serum levels of the omega-3 fatty acid eicosapentaenoic acid.We confirmed this inverse correlation between eicosapentaenoic acid and phagocytosis in the serum samples of the PRODEM cohort.In addition,in vitro testing of eicosapentaenoic acid on microglial phagocytosis showed a concentration-dependent decrease in phagocytic uptake.In conclusion,following incubation with Alzheimer’s disease blood serum,we observed increased microglial phagocytic uptake and the downregulation of TFEB and ATP6V1B2,possibly indicating lysosomal dysfunction.Furthermore,microglial phagocytosis was inversely correlated with serum eicosapentaenoic acid levels,suggesting an important role for dietary eicosapentaenoic acid in microglial function.
基金supported by the National Key Research and Development Program of China,No.2022YFC2704801(to CZhu)the National Natural Science Foundation of China,Nos.U21A20347(to CZhu),82203969(to YX),82371472(to XZ)+3 种基金Health Commission of Henan Province,Nos.SBGJ202303039(to XZ),SBGJ202301009(to CZhu),YQRC2024018(to XZ),YQRC2024019(to YX)Henan Science and Technology Department,Nos.242102311054(to XZ),241111521300(to CZhu),GZS2023003(to XW)Swedish Research Council,Nos.2022-01019(to CZhu),2021-01950(to XW)Swedish Governmental Grants to Scientists Working in Healthcare,Nos.ALFGBG-1005209(to CZhu),ALFBG-1005257(to XW),ALFGBG-965197(to CZhu).
文摘Germinal matrix hemorrhage in preterm neonates often leads to white matter injury,contributing to long-term neurodevelopmental impairments.As resident brain immune cells,microglia play a complex role in injury response,including inflammation and repair.Although colony-stimulating factor 1 receptor inhibitors such as PLX5622 enable the selective depletion of microglia,their therapeutic potential in neonatal germinal matrix hemorrhage remains underexplored.Here,we used a collagenase-induced germinal matrix hemorrhage model in postnatal day 5 mice,and intraperitoneally administered PLX562272 hours post-germinal matrix hemorrhage to achieve targeted,temporary microglial depletion during the peak injury response.We then assessed the effects of this delayed intervention on oligodendrocyte lineage cell maturation,white matter integrity,and neurobehavioral outcomes.Additionally,RNA sequencing data from a germinal matrix hemorrhage rat model were analyzed using weighted gene co-expression network analysis to identify the critical phases for interventions.RNA sequencing data revealed a critical period in which key synaptic functions declined while immune responses intensified post-germinal matrix hemorrhage,thus pinpointing the critical response phases for potential interventions.Delayed PLX5622 treatment effectively depleted activated microglia,protecting against white matter injury and enhancing oligodendrocyte lineage cell maturation and myelination in subcortical white matter regions.Moreover,magnetic resonance imaging analysis revealed reduced brain lesion volumes in treated mice.Behaviorally,PLX5622-treated mice exhibited significant improvements in motor coordination and reduced hyperactivity compared with vehicle-treated germinal matrix hemorrhage model mice.These findings suggest that,when timed to avoid interference with initial oligodendrocyte lineage cell proliferation,targeted microglial depletion with PLX5622 significantly mitigates white matter damage and improves neurobehavioral outcomes in neonatal germinal matrix hemorrhage.The present study highlights the therapeutic potential of selectively modulating microglial reactivity to support neurodevelopment in preterm infants with brain injury.
基金supported by the National Natural Science Foundation of China,Nos.82304990(to NY),81973748(to JC),82174278(to JC)the National Key R&D Program of China,No.2023YFE0209500(to JC)+4 种基金China Postdoctoral Science Foundation,No.2023M732380(to NY)Guangzhou Key Laboratory of Formula-Pattern of Traditional Chinese Medicine,No.202102010014(to JC)Huang Zhendong Research Fund for Traditional Chinese Medicine of Jinan University,No.201911(to JC)National Innovation and Entrepreneurship Training Program for Undergraduates in China,No.202310559128(to NY and QM)Innovation and Entrepreneurship Training Program for Undergraduates at Jinan University,Nos.CX24380,CX24381(both to NY and QM)。
文摘Early life stress correlates with a higher prevalence of neurological disorders,including autism,attention-deficit/hyperactivity disorder,schizophrenia,depression,and Parkinson's disease.These conditions,primarily involving abnormal development and damage of the dopaminergic system,pose significant public health challenges.Microglia,as the primary immune cells in the brain,are crucial in regulating neuronal circuit development and survival.From the embryonic stage to adulthood,microglia exhibit stage-specific gene expression profiles,transcriptome characteristics,and functional phenotypes,enhancing the susceptibility to early life stress.However,the role of microglia in mediating dopaminergic system disorders under early life stress conditions remains poorly understood.This review presents an up-to-date overview of preclinical studies elucidating the impact of early life stress on microglia,leading to dopaminergic system disorders,along with the underlying mechanisms and therapeutic potential for neurodegenerative and neurodevelopmental conditions.Impaired microglial activity damages dopaminergic neurons by diminishing neurotrophic support(e.g.,insulin-like growth factor-1)and hinders dopaminergic axon growth through defective phagocytosis and synaptic pruning.Furthermore,blunted microglial immunoreactivity suppresses striatal dopaminergic circuit development and reduces neuronal transmission.Furthermore,inflammation and oxidative stress induced by activated microglia can directly damage dopaminergic neurons,inhibiting dopamine synthesis,reuptake,and receptor activity.Enhanced microglial phagocytosis inhibits dopamine axon extension.These long-lasting effects of microglial perturbations may be driven by early life stress–induced epigenetic reprogramming of microglia.Indirectly,early life stress may influence microglial function through various pathways,such as astrocytic activation,the hypothalamic–pituitary–adrenal axis,the gut–brain axis,and maternal immune signaling.Finally,various therapeutic strategies and molecular mechanisms for targeting microglia to restore the dopaminergic system were summarized and discussed.These strategies include classical antidepressants and antipsychotics,antibiotics and anti-inflammatory agents,and herbal-derived medicine.Further investigations combining pharmacological interventions and genetic strategies are essential to elucidate the causal role of microglial phenotypic and functional perturbations in the dopaminergic system disrupted by early life stress.
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,Nos.82104560(to CL),U21A20400(to QW)the Natural Science Foundation of Beijing,No.7232279(to XW)the Project of Beijing University of Chinese Medicine,No.2022-JYB-JBZR-004(to XW)。
文摘The primary mechanism of secondary injury after cerebral ischemia may be the brain inflammation that emerges after an ischemic stroke,which promotes neuronal death and inhibits nerve tissue regeneration.As the first immune cells to be activated after an ischemic stroke,microglia play an important immunomodulatory role in the progression of the condition.After an ischemic stroke,peripheral blood immune cells(mainly T cells)are recruited to the central nervous system by chemokines secreted by immune cells in the brain,where they interact with central nervous system cells(mainly microglia)to trigger a secondary neuroimmune response.This review summarizes the interactions between T cells and microglia in the immune-inflammatory processes of ischemic stroke.We found that,during ischemic stroke,T cells and microglia demonstrate a more pronounced synergistic effect.Th1,Th17,and M1 microglia can co-secrete proinflammatory factors,such as interferon-γ,tumor necrosis factor-α,and interleukin-1β,to promote neuroinflammation and exacerbate brain injury.Th2,Treg,and M2 microglia jointly secrete anti-inflammatory factors,such as interleukin-4,interleukin-10,and transforming growth factor-β,to inhibit the progression of neuroinflammation,as well as growth factors such as brain-derived neurotrophic factor to promote nerve regeneration and repair brain injury.Immune interactions between microglia and T cells influence the direction of the subsequent neuroinflammation,which in turn determines the prognosis of ischemic stroke patients.Clinical trials have been conducted on the ways to modulate the interactions between T cells and microglia toward anti-inflammatory communication using the immunosuppressant fingolimod or overdosing with Treg cells to promote neural tissue repair and reduce the damage caused by ischemic stroke.However,such studies have been relatively infrequent,and clinical experience is still insufficient.In summary,in ischemic stroke,T cell subsets and activated microglia act synergistically to regulate inflammatory progression,mainly by secreting inflammatory factors.In the future,a key research direction for ischemic stroke treatment could be rooted in the enhancement of anti-inflammatory factor secretion by promoting the generation of Th2 and Treg cells,along with the activation of M2-type microglia.These approaches may alleviate neuroinflammation and facilitate the repair of neural tissues.
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2022MH124the Youth Science Foundation of Shandong First Medical University,No.202201–105(both to YX)。
文摘Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.
文摘The development of neurodegenerative diseases is closely related to the disruption of central nervous system homeostasis.Microglia,as innate immune cells,play important roles in the maintenance of central nervous system homeostasis,injury response,and neurodegenerative diseases.Lactate has been considered a metabolic waste product,but recent studies are revealing ever more of the physiological functions of lactate.Lactylation is an important pathway in lactate function and is involved in glycolysis-related functions,macrophage polarization,neuromodulation,and angiogenesis and has also been implicated in the development of various diseases.This review provides an overview of the lactate metabolic and homeostatic regulatory processes involved in microglia lactylation,histone versus non-histone lactylation,and therapeutic approaches targeting lactate.Finally,we summarize the current research on microglia lactylation in central nervous system diseases.A deeper understanding of the metabolic regulatory mechanisms of microglia lactylation will provide more options for the treatment of central nervous system diseases.
基金supported by the National Natural Science Foundation of China,Nos.82071387(to HT),81971172(to YW)the Natural Science Foundation of Zhejiang Province,China,No.LY22H090012(to HT)the Basic Research Project of Wenzhou City,China,No.Y20220923(to MZ)。
文摘The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia polarization from M1(neurotoxic and proinflammatory type)to M2(neuroprotective and anti-inflammatory type)after spinal cord injury appears to be crucial.Tryptanthrin possesses an anti-inflammatory biological function.However,its roles and the underlying molecular mechanisms in spinal cord injury remain unknown.In this study,we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro.Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway.Additionally,we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury,inhibited neuronal loss,and promoted tissue repair and functional recovery in a mouse model of spinal cord injury.Finally,using a conditional co-culture system,we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis.Taken together,these results suggest that by targeting the cGAS/STING/NF-κB axis,tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype.
