Objective:Neuropathic pain(NP)is one of the most common forms of chronic pain,yet current treatment options are limited in effectiveness.Peripheral nerve injury activates spinal microglia,altering their inflammatory r...Objective:Neuropathic pain(NP)is one of the most common forms of chronic pain,yet current treatment options are limited in effectiveness.Peripheral nerve injury activates spinal microglia,altering their inflammatory response and phagocytic functions,which contributes to the progression of NP.Most current research on NP focuses on microglial inflammation,with relatively little attention to their phagocytic function.Early growth response factor 2(EGR2)has been shown to regulate microglial phagocytosis,but its specific role in NP remains unclear.This study aims to investigate how EGR2 modulates microglial phagocytosis and its involvement in NP,with the goal of identifying potential therapeutic targets.Methods:Adult male Sprague-Dawley(SD)rats were used to establish a chronic constriction injury(CCI)model of the sciatic nerve.Pain behaviors were assessed on days 1,3,7,10,and 14 post-surgery to confirm successful model induction.The temporal and spatial expression of EGR2 in the spinal cord was examined using real-time quantitative PCR(RT-qPCR),Western blotting,and immunofluorescence staining.Adeno-associated virus(AAV)was used to overexpress EGR2 in the spinal cord,and behavioral assessments were performed to evaluate the effects of EGR2 modulation of NP.CCI and lipopolysaccharide(LPS)models were established in animals and microglial cell lines,respectively,and changes in phagocytic activity were measured using RT-qPCR and fluorescent latex bead uptake assays.After confirming the involvement of microglial phagocytosis in NP,AAV was used to overexpress EGR2 in both in vivo and in vitro models,and phagocytic activity was further evaluated.Finally,eukaryotic transcriptome sequencing was conducted to screen differentially expressed mRNAs,followed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses to identify potential downstream effectors of EGR2.Results:The CCI model successfully induced NP.Following CCI,EGR2 expression in the spinal cord was upregulated in parallel with NP development.Overexpression of EGR2 via spinal AAV injection enhanced microglial phagocytic activity and increased pain hypersensitivity in rats.Both animal and cellular models showed that CCI or LPS stimulation enhanced microglial phagocytosis,which was further amplified by EGR2 overexpression.Transcriptomic analysis of spinal cord tissues from CCI rats overexpressing EGR2 revealed upregulation of numerous genes associated with microglial phagocytosis and pain regulation.Among them,Lag3 emerged as a potential downstream target of EGR2.Conclusion:EGR2 contributes to the maintenance of NP by enhancing microglial phagocytosis in the spinal dorsal horn.展开更多
OBJECTIVE Neuroinflammation is considered to be an important and inevitable pathological process associated with all types of damages to the central nervous system.The hallmark of neuroinflammation is the microglia ac...OBJECTIVE Neuroinflammation is considered to be an important and inevitable pathological process associated with all types of damages to the central nervous system.The hallmark of neuroinflammation is the microglia activation.In response to different micro-environmental disturbances,microglia could polarize into either an M1 pro-inflammatory phenotype,exacerbating neurotoxicity,or an M2 anti-inflammatory phenotype,exerting neuroprotection.Therefore,shifting the polarization of microglia toward the M2 phenotype could possess a more viable strategy for the neuroinflammatory disorders treatment.Naringenin(NAR) is natural y a grapefruit flavonoid and possesses various kinds of pharmacological activities,such as anti-inflammatory and neuroprotective activities.In the present study,we aimed to investigate the potential effects of NAR on microglial M1/M2 polarization and further reveal the underlying mechanisms of actions.METHODS BV-2 cells were pretreated with NAR(100 μmol·L^(-1)) for 1 h and then incubated with LPS(1 mg·L^(-1)) for 24 h.The effects of NAR on LPS-induced microglia activation,microglial M1/M2 polarization and MAPK pathways were detected.In addition,BV-2 cells were incubated with or without anisomycin(ANI,a selective agonist of JNK) to evaluate the role of JNK on microglia activation and microglia M1/M2 polarization.RESULTS First,NAR inhibited LPS-induced microglial activation.Then,NAR shifted the M1 pro-inflammatory microglia phenotype to the M2 anti-inflammatory M2 microglia state as demonstrated by the decreased expression of M1 markers,ie,inducible tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and the elevated expression of M2 markers(ie,arginase 1,IL-4 and IL-10).In addition,the effects of NAR on microglial polarization was dependent on MAPK signaling,particularly JNK inactivation,as evidenced by the fact that the selective activator of JNK abolished NAR-promoted M2 polarization and further NAR-inhibited microglial activation.CONCLUSION NAR promotes microglia M1/M2 polarization,thus conferring anti-neuroinflammatory effects via the inhibition of MAPK signaling activation.These findings might provide new alternative avenues for neuroinflammation-related disorders treatment.展开更多
OBJECTIVE Inhibition of phosphodiesterase 4(PDE4) improves the learning and memory abilities in Alzheimer disease animal models. The cognition-enhancing effects of PDE4 inhibition involve reduced inflammatory response...OBJECTIVE Inhibition of phosphodiesterase 4(PDE4) improves the learning and memory abilities in Alzheimer disease animal models. The cognition-enhancing effects of PDE4 inhibition involve reduced inflammatory responses in the brain. However,the underlying mechanisms are illunderstood. cA MP induces autophagy,and deficiency of autophagy leads to elevated inflammatory factors.In the present study,we aimed to investigate the contribution of autophagy to the anti-inflammatory effect of PDE4 inhibitor ROF. METHODS Acidic vesicles were traced by Lysotracker(LYT) red and acridine orange(AO) staining. Autophagosomes in BV-2 cells was observed by immunofluorescence staining of microtubule-associated protein 1 light chain 3(LC3). Aβ_(25-35) or lipopolysaccharide(LPS) with ATP were used to activate microglial cells and inflammasome. Cytokine levels were measured by ELISA method. The levels of pro-inflammatory factors and essential proteins involved in the formation of autophagosome were detected by Western blotting. RESULTS ROF increased the level of LC3-Ⅱ,while the level of p62 was decreased. Enhanced fluorescent signals were observed in BV-2 cells treated with ROF by AO and LYT red staining. In addition,immunofluorescence indicated a significant increase in punctate LC3. Both LPS plus ATP and Aβ_(25-35) enhanced the conversion of pro-caspase-1 to cleaved-caspase-1 and increased the production of mature IL-1β. Interestingly,these effects were blocked by the treatment of ROF. Moreover,ROF decreased the apoptosis of neuronal N2 a cells in conditioned media from BV-2 microglia. These effects were reversed by inhibition of microglial autophagy.Treatment with ROF also showedenhanced autophagy in mcie treated with LPS. CONCLUSION PDE4 inhibitor ROF inhibits inflammasome activities and reduces the release of IL-1β by inducing autophagy.展开更多
OBJECTIVE Microglia-mediated dis-placement of synapses has been reported in the setting of experimental neuroinflammation,but its role in neurological disorders is poorly understood.Complex febrile seizures(FS)are the...OBJECTIVE Microglia-mediated dis-placement of synapses has been reported in the setting of experimental neuroinflammation,but its role in neurological disorders is poorly understood.Complex febrile seizures(FS)are the most common infantile seizures,yet its pathological progress is largely unknown.METHODS Mice pups(postnatal 8-10 d)were posted to 43℃hyperthermia condition to develop FS,and then the latency and threshold of seizures were determined.The displacement of synapses was observed through immunofluorescence staining.We researched whether microglial displacement of GABAergic synapses will influence complex FS-induced increase in GABAergic neurotransmission and neuronal excitability with patch-clamp electrophysiology.Moreover,we used the CD11 bD TR mice to selective ablation of microglia or pharmacological inhibition of microglia to observe their effects on susceptibility to FS and synaptic stripping.RESULTS GABAergic presynaptic terminals surrounding neuronal soma and GABAergic transmissions were increased in complex FS.Meanwhile,the activated microglia ensheathe glutamatergic neuronal soma to displace,but do not phagocytize,GABAergic presynaptic terminals.Patch-clamp electrophysiology established that the microglial displacement of GABAergic synapses reduced complex FS-induced increase in GABAergic neurotransmission and neuronal excitability,while GABA exerts excitatory action in this immature stage.Moreover,pharmacological inhibition of microglial displacement of GABAergic synapses or selective ablation of microglia in CD11 bDTR mice promoted the generation of complex FS.CONCLUSION Displacement of GABAergic synapses by microglia is a protective event in the pathological progress of complex FS.展开更多
OBJECTIVE Oleoylethanolamide(OEA) has shown neuroprotective effect in treating acute and chronic ischemic stroke.However,it is unclear whether OEA is able to modulate microglia/macrophage polarization,which has recent...OBJECTIVE Oleoylethanolamide(OEA) has shown neuroprotective effect in treating acute and chronic ischemic stroke.However,it is unclear whether OEA is able to modulate microglia/macrophage polarization,which has recently been documented to be important in the pathology of ischemic stroke.This study explored the potential role of OEA in modulating the microglial phenotypes.METHODS In vivo,middle cerebral artery occlusion(MCAO) was induced in both PPARα-/-(KO) and wild-type(WT)mice.In vitro,primary cortical microglia or neuron or coculture from KO/WT mice was subjected to oxygen glucose deprivation(OGD).Western blotting and immunofluorescence were used for detecting the specialized protein expression of M1/M2,such as CD206 and CD16/32.q PCR was utilized to detect the signature gene change of M1/M2.RESULTS OEA significantly reduced neuron damage of mice after MCAO.More importantly,OEA promoted microglia/macrophage transferring from inflammatory M1 phenotype to a protective,anti-inflammatory M2 phenotype in vivo or in vitro.Interestingly,these benifical effects of OEA could not be observed in the KO mice or KO microglia.CONCLUSION Our results reveal a novel pharmacological effect of OEA in modulating microglia/macrophage polarization after MCAO,thus depening our understanding of neuroprotective mechanisms of OEA in treatment of ischemic stroke.Furthermore,this new mechanism may allow OEA to be used in many other microglia/macrophage polarizationrelated inflammatory diseases.展开更多
OBJECTIVE To establish an in vitro cel model based on patient-specific human microglia to study the pathological mechanism of Alzheimer disease(AD) and to screen candidate drugs.METHODS First,the induced pluripotent s...OBJECTIVE To establish an in vitro cel model based on patient-specific human microglia to study the pathological mechanism of Alzheimer disease(AD) and to screen candidate drugs.METHODS First,the induced pluripotent stem cells(iPSCs) of AD patients and cognitive normal controls(CNC) were induced to hematopoietic progenitor cells(HPCs),and then HPCs were further induced with IL-34,M-CSF,GM-CSF and TGF-β1 for 20 d to obtain microglialike cells(MGLCs).HPCs were isolated by flow cytometry and MGLCs were identified by immunofluorescence.Cell phagocytosis was determined by phagocytosis neutral red experiusing Luminex assay kits,and the cell growth curve during the experiment was recorded by IncuCyte ZOOM.The phagocytic ability and secretion of cytokines of MGLCs were observed under the stimulation of LPS.RESULTS MGLCs from AD patients(AD-MGLCs) and CNC expressed microglia markers IBA1,TMEM119,P2 RY12,TREM2 and CD11 B.The results of phagocytosis neutral red experiment showed that under normal conditions,AD-MGLCs had stronger phagocytic ability(P<0.01).Stimulation by LPS resulted in increased phagocytosis of cel s,and the increase in phagocytosis of CNC-MGLCs was higher than AD-MGLCs(P<0.01).Experiments showed that high concentrations of LPS(>2 mg·L^(-1)) resulted in CNC-microglia death(P<0.01),whereas ADMGLCs did not show significant death.The cytokine assay showed that under normal conditions,the concentrations of IFN-γ and IL-2 secreted by AD patients were slightly higher than those of CNC.After LPS stimulation,the secretion of TNF-α,IL-6 and IL-10 was significantly increased.The increased secretion of AD-MGLCs was greater than that CNC-MGLCs(P<0.01).CONCLUSION AD-iPSCs derived MGLCs exhibit significant inflammatory characteristics and are more active than CNC,which may be associated with chronic inflammatory responses caused by microglia in AD,thus may provide valuable new tools to screen candidate drugs for the disease and to discover the mechanisms underlying AD pathogenesis.展开更多
OBJECTIVE To investigate the protective effect of icariin(ICA) on lipopolysaccharide(LPS)-induced BV2 microglia injury,and to clarify the role of nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway in ...OBJECTIVE To investigate the protective effect of icariin(ICA) on lipopolysaccharide(LPS)-induced BV2 microglia injury,and to clarify the role of nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway in BV2 microglia-mediated neuroinflammation.METHODS BV2 microglia were randomly divided into control,ICA(0.1 μmol·L^(-1)),LPS(1 mg·L^(-1)),LPS + ICA(0.01 μmol·L^(-1)),and LPS + ICA(0.1 μmol·L^(-1))groups.BV2 microglia were treated with ICA for 30 min and then treated with LPS for 24 h.MTT assay was used to determine the cells survival rate,Griess kit and ELISA kits were used to detect the contents of NO,IL-1β and IL-18 in the culture supernatant,Western blotting was used to detect the expression of Nrf2,HO-1 and NQO1.Real time RT-PCR was used to detect the expression of Nrf2,HO-1 and NQO1 after ICA addition for 2,6 and 24 h.And immunofluorescence was used to observe the activation of Nrf2.RESULTS ICA reduced LPS-induced NO,IL-1β and IL-18 production in the culture supernatant,and ICA increase LPS-induced mRNA and protein expression of Nrf2 signaling pathway.CONCLUSION ICA protects LPS induced neuroinflammation by regulating Nrf2 signaling pathway.展开更多
OBJECTIVE Pleckstrin homologylike domain family A member 1(PHLDA1),also known as TDAG51,was first identified as a potential transcription factor required for Fas expression and activation-induced apoptosis in mouse T ...OBJECTIVE Pleckstrin homologylike domain family A member 1(PHLDA1),also known as TDAG51,was first identified as a potential transcription factor required for Fas expression and activation-induced apoptosis in mouse T cell hybridomas.Subsequent research showed that PHILDA1 plays crucial roles in cell proliferation and apoptosis,PHLDA1 deficiency caused several phenotypic changes in macrophages that increased cytoprotection against oxidative and endoplasmic reticulum(ER) stress.However,little is known about the critical role of PHLDA1 in the neuroinflammation and neuronal apoptosis.METHODS Mouse Parkinson disease(PD) model was induced by intraperitoneal injection(ip) of MPTP for 7 d.Immunohistofluorescence staining was used to observe TH,Iba-1 and PHLDA1 in brain slides.Primary microglia and BV2 microglial cell lines were exposed to lipopolysacchrides(LPS) at different time points to determine PHLDA1 mRNA and protein level in vitro.BV2 cells with PHLDA1 knockdown using lentivirus experessing shRNA were exposed to LPS for the detection of proinflammatory genes expression by q-PCR or Western blotting.The NF-κB and MAPK pathways were detected to reveal the underlying mechanisms of PHLDA1 regulate microglia activation.Furthermore,to determine the effect of PHLDA1 deletion in the substantia nigra(SN) on motor dysfunction,the mice were previously infected with AAV-GFP(control) or AAV-shP HLDA1 in the SN in PD model,then were administered with behavior assessment.RESULTS PHLDA1 was expressed in microglia.PHLDA1 was increased in primary microglia or BV2 microglia cell lines by LPS treatment,acted as a positive regulator of TLR4 signaling.PHLDA1 deficiency suppressed LPS-induced microglia activation.The underlying mechanisms of PHLDA1 might be through directly interacting with TRAF6 to promote its auto-ubiquitination consequently enhanced neuroinflammatory.In PD model,PHLDA1 deletion in the SN limits microglial activation and protects dopaminergic neurons.PHLDA1 deficiency mice have a good behavioral score.CONCLUSION PHLDA1 deficiency in SN limits microglial inflammatory responses and protects dopaminergic neurons through attenuating auto-ubiquitination of TRAF6 in PD model.展开更多
OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine micr...OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine microglial morphological changes and the upstream molecular underlying IL^(-1)β production in Cys LT receptor agonist leukotriene D4(LTD4)-treated BV2 microglia in vitro.METHODS Twenty-four hours after murine microglial BV2 cells were stimulated with LTD4(1-100 nmol·L^(-1)),the cell proliferation and morphology were observed.The expression level of cysteinyl aspartate-specific protease 1(CASP1) protein was measured by Western blotin BV2 cells.In addition,BV2 cells were pretreated with or without CysLT1 receptor antagonist montelukast for 1 h and the effects of monte-lukaston LTD4-stimulated microglial activation and CASP1 expression were evaluated.RESULTS The number of BV2 cells had an increasing tendency after 24 h treatment with LTD4,but no significant differences were observed between the control and LTD4-treated cells(P>0.05).Under basal and resting conditions,BV2 microglial cells displayed a ramified morphology.However,LTD4 at 100 nmool·L^(-1) drove microglial morphological changes from a ramified towards an amoeboid shape.The expression of CASP1 protein was significantly upregulated in 100 nmool·L^(-1) LTD4-treated BV2 microglia(P<0.01).Furthermore,pretreatment with CysLT1 receptor antagonist montelukast prevented cell morphological changes and suppressed the increased CASP1 expression in LTD4-treated BV2 cells(P<0.05).CONCLUSION Cys LT receptor agonist LTD4 induces morphological changes and CASP1 expressionin BV2 microglia,which can be inhibited by CysLT1 antagonist.These results suggest the involvement of Cys LT signaling in microglial morphological changes and CASP1 expression.展开更多
OBJECTIVE Microglial activation contributes to neuroinflammation and neuronal damages in neurodegenerative disorders including Alzheimer and Parkinson diseases.It has been suggested that neurodegenerative disorders ma...OBJECTIVE Microglial activation contributes to neuroinflammation and neuronal damages in neurodegenerative disorders including Alzheimer and Parkinson diseases.It has been suggested that neurodegenerative disorders may be improved if neuroinflammation can be controlled.Isoliquiritigenin(ISL)isolated from Glycyrrhiza glabra possess potent anti-inflammatory capability,we thus investigate the inhibitory effects of ISL on LPS-induced microglial activation and neuroinflammation and the roles of neuroprotection on neurodegenerative disorders.Moveover,we would explore the mechanism of itsassociated inflammatory signaling passway.METHODS By cultivating,isolating and purifying,we got the primary microglia of the rat.The form of those cells was observed under an optical microscope,the purity was identified by the CD11b immunefluorescence staining.Firstly,the effects of ISL on microglial viability were explored by the MTT assay.The microglial cells were pretreated by ISL(5μmol·L-1)and then stimulated by LPS(100 ng·mL-1),the production of NO was detected by Griess reagent,the change of microglial morphology was observed by immunefluorescence staining.The production of IL-1βand TNF-αin culture medium were tested by ELISA,and the m RNA expression of pro-inflammatory factors,including IL-1β,TNF-α,i NOS and COX-2 was detected by real time PCR.The protein expression of i NOS and COX-2was detected by Western blotting.RESULTS(1)After purifying,microglial showed the typical morphological characteristics.The cell body was small,protruding outstretched in the branch rod,spindle.After LPS stimulation,the shape was changed to amoeba-like,and the protrusions retracted,cell rounding.In the CD11b immunefluorescence staining,the purity of the microglial was over 98%,and showed powerful phagocytic activity.(2)The results show that ISL(0.16-20μmol·L-1)concentration has no effect on primary microglia′s vitality.And at the concentration of 5μmol·L-1ISL has the significantly inhibitory effect on NO production induced by LPS.(3)The results shows that ISL pretreatment can significantly inhibit LPS-induced microglial activation,and can significantly reduce the production of NO in a dose-dependent manner(P<0.05).When stimulated by LPS for12 h,the expression of TNF-αand IL-1βm RNA in the culture medium are reduced by ISL pre-treatment(P<0.05).After LPS stimulation for 24 h,the expression of COX2 and i NOS m RNA and protein can be reduced(P<0.05).After stimulated by LPS from 0.5 to 2 h,p-ERK expression has be decreased.CONCLUSION We successfully obtain primary microglia with high-purity by culturing in vitro.We find that ISL can significantly reduce the levels of proinflammatory facters,which indicate ISL can inhibit microglia activation and neuroinflammation by blocking ERK1/2 signal pathway.展开更多
OBJECTIVE Brain inflammation plays an important role in the pathophysiology of brain ischemicstroke,psychiatric and neurological diseases.During brain inflammation,microglia cells are activated and show pro-inflammato...OBJECTIVE Brain inflammation plays an important role in the pathophysiology of brain ischemicstroke,psychiatric and neurological diseases.During brain inflammation,microglia cells are activated and show pro-inflammatory M1 and anti-inflammatory M2 phenotypes,producing neurotoxic molecules and neurotrophic factors,respectively.We have previously discovered a novel natural product compound 3c exhibiting antiinflammatory effects in microglia cells,but the underlying mechanisms and its beneficial effects on brain inflammation and brain ischemia are unknown.METHODS The gene expression of M1 markers and M2 markers was measured by RT-PCR.The AMPK phosphorylation level and M2 marker CD206 protein expression were determined by Western blotting.TNFαrelease was measured by ELISA.The gene knowdown was performed by the si RNA transfection experiment.The LPS-induced brain inflammation mouse model and transient middle cerebral artery occlusion(t MCAO)stroke model were used.RESULTS We found that compound 3c inhibited M1polarization and promoted M2 polarization in LPS-stimulated BV2 and primary microglia cells,and these effects are mediated by Ca MKKβ/AMPK/JNK signaling pathway.Furthermore,compound 3c prevented M1 gene expression and enhanced M2 gene expression in a mouse model of LPS-induced neuroinflammation,and reduced the LPS-induced sickness behavior.In addition,compound 3c significantly reduced infarct volume,improved the neurological deficit,and reduced neuroinflammation in rats with acute focal cerebral ischemia.CONCLUSION Our results indicate that natural product compound 3c suppresses microglia activation by promoting M2 polarization and may provide a novel therapeutic approach to treat brain ischemic stroke associated with enhanced brain inflammation.展开更多
Microglia activation induced neuroinflammation closely relates with the development of Parkinson disease. Autophagy regulates many biological processes,but the role in microglial activation and the development of Park...Microglia activation induced neuroinflammation closely relates with the development of Parkinson disease. Autophagy regulates many biological processes,but the role in microglial activation and the development of Parkinson disease is not clear. In this study,we show that loss of microglial Atg5 cause neuroinflammation and motor and cognitive learning impairment in mice,with accumulation of α-synuclein and decrease of dopamine levels in the striatum. Inhibition of autophagy aggravates the activation of NLRP3 inflammasome via PDE10a-cAMP signaling in microglia. Furthermore,the downstream cytokine IL-1 increases Mif levels in a transcriptional dependent manner. Interestingly,Mif levels are significantly elevated in Parkinson disease patients. Taken together,our results reveal a protective role of autophagy in microglial activation-driven Parkinson disease,thus providing a potential targets for the clinical treatment.展开更多
Aim Brain inflammation plays an important role in the pathophysiology of many psychiatric and neuro- logical diseases. Angiotensin II type 1 receptor blockers （ARBs） ameliorate brain inflammation and reduce M1 mi- c...Aim Brain inflammation plays an important role in the pathophysiology of many psychiatric and neuro- logical diseases. Angiotensin II type 1 receptor blockers （ARBs） ameliorate brain inflammation and reduce M1 mi- croglia activation. The ARB telmisartan suppresses neuroinflammation in cultured neuronal cells. We wished to clarify whether telmisartan prevents microglia-mediated neuroinflammation through microglia polarization to an anti- inflammatory M2 phenotype. Methods The gene expression of M1 markers and M2 markers was measured by RT- PCR. The AMPK phosphorylation level and M2 marker CD206 protein expression were determined by Western blot. TNF-α and IL-10 release was measured by ELISA. The gene knowdown was performed by the siRNA transfec- tion experiment. Results Our results demonstrated that telmisartan promoted M2 polarization in LPS-stimulated BV2 and primary microglia cells. The promoting effects of telmisartan on M2 polarization were attenuated by an AMP-activated protein kinase （AMPK） inhibitor or AMPK knockdown, indicating that AMPK activation partici- pates on telmisartan effects. Furthermore, telmisartan enhanced brain AMPK activation and M2 gene expression in a mouse model of LPS-induced neuroinflammation. Conclusion Our results indicate that telmisartan can be con- sidered as a novel AMPK activator, suppressing neuroinflammation by promoting microglia M2 polarization. Telmis- artan may provide a novel and safe therapeutic approach for the treatment of brain disorders associated with neuroin- flammation.展开更多
Aim p53 up-regulated modulator of apoptosis （PUMA） is a known apoptosis inducer; however its role in microglial survival remains poorly understood. In addition to the classical transcription factor p53, microRNA- ...Aim p53 up-regulated modulator of apoptosis （PUMA） is a known apoptosis inducer; however its role in microglial survival remains poorly understood. In addition to the classical transcription factor p53, microRNA- 143 （miR-143） is involved in PUMA expression at the post-transcriptional level. Furthermore, they identify unique roles of miR-143/PUMA in mediating microglial survival via the regulation of apoptosis and autophagy interplay. Results Blockage of autophagy accelerated methamphetamine-induced apoptosis, whereas the induction of autoph- agy attenuated the decrease in microglial survival. Moreover, anti-miR-143-dependent PUMA up-regulation re- versed the methamphetamine-induced decrease in microglial survival via the regulation of apoptosis and autophagy. The in vivo relevance of these findings was confirmed in mouse models, which demonstrated that the microinjection of anti-miR-143 into the hippocampus ameliorated the methamphetamine-induced decrease in microglia as well as that observed in heterozygous miR-143 ^＋/- mice. Conclusion These findings provided new insight for the specific contributions of miR-143/PUMA to microglial survival in the context of drug abuse.展开更多
Microglia are the principal immune effectors in central nervous system and plays an extremely important role in the central nervous system disease. Under physiological conditions, resting state microglia plays a role ...Microglia are the principal immune effectors in central nervous system and plays an extremely important role in the central nervous system disease. Under physiological conditions, resting state microglia plays a role of nu- trition, support and protection of neurons. Interestingly, recent studies have revealed that resting microglia processes make brief and direct contacts with neuronal synapses at a frequency of about once per hour and through these con- tacts monitoring the function and state of the synapses, providing the brain with a dynamic and efficient monitoring system. Microglia can be quickly activated and proliferated after cerebral ischemia. It exerts dual effects by produ- cing neurotoxic molecules and neurotrophic factors. Therefore, studying the relationship between brain ischemia in- jury and microglia, give full play to its protective function and reduce its damage, will shed a light on the treatment of cerebral ischemia.展开更多
Aim Following cerebral isehemia, microglia respond to the injury acting as the first defense of central nervous system. Activated microglia play a dual role in the ischemie injury depending on the phenotype of micro-...Aim Following cerebral isehemia, microglia respond to the injury acting as the first defense of central nervous system. Activated microglia play a dual role in the ischemie injury depending on the phenotype of micro- gila, including deleterious M1 phenotype and neuroprotective M2 phenotype. However, microglia show transient M2 phenotype followed by a transition to M1 phenotype aggravating the ischemic injury. Many signal pathways par- ticipate in the modulation of microglial polarization , presenting potential therapeutic targets for selectively inducing the polarization of M2 microglia. In this review, we discuss M2 microglia phenotype mediated neuroprotective role and the signaling cascades controlling microglial phenotype after ischemic stroke.展开更多
Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulley...Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulleya- conitine A （ BAA or BLA） is an aconitine analog and has been prescribed for the management of pain. The present study aimed to evaluate the inhibitory effects of BAA on pain hypersensitivity and morphine anti-nociceptive toler- ance, and explore whether the release of dynorphin A from spinal microglia was associated with its mechanism of actions. Methods Rat models of neuropathic pain, formalin test and bone cancer pain were used, and spinal dynorphin A level and expression were measured. Sample size of animals was six in each study group. Resultes A single intrathecal or subcutaneous （but not intraventricular or local） injection of BAA blocked spinal nerve liga- tion-induced painful neuropathy, bone cancer-induced pain and formalin-induced hyperalgesia by 60% - 100% with the ED50 values of 94 - 126 ng/rat （intrathecal） and 42 - 59 μg · kg^-1 （ subcutaneous）, respectively. Follow- ing chronic treatment, BAA did not induce either self-tolerance to anti-nociception or cross-tolerance to morphine anti-nociception, and completely prevented morphine tolerance. Spinal BAA anti-nociception, but not neurotoxici- ty, was completely blocked by the specific microglial inhibitor minocycline. In a minocycline-sensitive and lido- BAA stimulated the release of dynorphin A from the spinal cord, and the caine- or ropivacaine-insensitive manner, primary culture of microglia but not from neurons or astrocytes. The blockade effects of BAA on nociception and morphine tolerance were completely blocked by the specific dynorphin A antiserum and/or K-opioid receptor antago- nist. Conclusions Our results demonstrated that BAA eliminated pain hypersensitivity and morphine tolerance through the direct stimulation of dynorphin A release from spinal microglia, which was not dependent on the interac- tions with sodium channels.展开更多
OBJECTIVE To establish an in vitro inflammatory model of BV2 by observing the activity,the release amount of NO and the expression of inflammatory factors of microglial cells(BV2)induced by lipopolysaccharides(LPS).ME...OBJECTIVE To establish an in vitro inflammatory model of BV2 by observing the activity,the release amount of NO and the expression of inflammatory factors of microglial cells(BV2)induced by lipopolysaccharides(LPS).METHODS BV2 was routinely cultured in vitro.Cell viability was measured by CCK-8 meth⁃od.And by drew cell growth curve to determine the logarithmic growth cycle of the cells.After 24 h of routine culture,BV2 were induced by adding different concentrations of LPS(0.1,1.0 and 10.0 mg·L-1)for 4,8,12,24 and 48 h,respectively.Meanwhile,the morphological changes of BV2 were observed under inverted microscope to compare the activation degree of microglia at dif⁃ferent time and concentration.Cell activity and nitric oxide(NO)level were determined by CCK-8 and Griess method respectively,which could help to determine the optimal concentration and time of modeling.Finally,It were determined by ELISA that the concentrations of tumor necrosis factorα(TNF-α),interleukin-6(IL-6)and IL-1βin supernatant of LPS 1 mg·L-1 culture for 24 h.RESULTS BV2 were in logarithmic growth phase for 1 to 3 d after subculture.LPS 1 mg·L-1 induced BV2 for 24 or 48 h which could increase the release amount of NO significantly(P<0.05).In order to save time,LPS induced BV2 for 24 h were selected for subsequent experiments.Microglial cells in resting state were observed to be elongated spindle shape under inverted micro⁃scope.After LPS activation,the cell body became larger and the branching processes shrank back,presenting an amoeba-like appearance.ELISA results showed that the concentrations of TNF-α,IL-6 and IL-1βin supernatant of LPS 1 mg·L-1 cultured for 24 h were significantly increased which compared with the control group(P<0.05).CONCLUSION LPS could induce the activation of BV2 and up-regulate the level of inflammatory factors.The optimal condition for establishing stable BV2 microglial inflammatory model was used LPS 1 g·L-1 induced for 24 h.展开更多
OBJECTIVE Microglial activation-mediated neuroinflammation plays an important pathological basis in the progression of many neurodegenerative diseases.Activated microglia cells show a metabolic shift from oxidative ph...OBJECTIVE Microglial activation-mediated neuroinflammation plays an important pathological basis in the progression of many neurodegenerative diseases.Activated microglia cells show a metabolic shift from oxidative phos⁃phorylation to aerobic glycolysis.However,the molecular mechanism underlying the role of glycolysis in microglial activation and progres⁃sion of neuroinflammatory diseases have not yet been fully understood.METHODS The anti-inflammatory effects and its underlying mecha⁃nisms of glycolytic inhibition in vitro were exam⁃ined in lipopolysaccharide(LPS)activated BV-2 microglial cells or primary microglial cells by enzyme-linked immunosorbent assay(ELISA),quantitative reverse transcriptase polymerase chain reaction(RT-PCR),Western blotting,immunoprecipitation,Flow cytometry and nuclear factor kappa B(NF-κB)luciferase reporter assays.In vivo,the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-or LPS-induced Par⁃kinson disease(PD)models were constructed to explored the anti-inflammatory and neuropro⁃tective effects of glycolytic inhibitor.RESULTS Inhibition of glycolysis by specific inhibitors[2-DG and 3-bromopyruvic acid(3-BPA)],knockdown of glucose transporter type 1(Glut-1)or hexoki⁃nase(HK)Ⅱabolished LPS-induced expres⁃sion of proinflammatory genes in microglia cells.Mechanistic studies demonstrated that glyco⁃lytic inhibitors significantly inhibited LPS-induced mTOR phosphorylation,IKKβphosphorylation,IκB phosphorylation,IκB degradation,nuclear translocation of P65 and NF-κB luciferase activity.Furthermore,LPS-induced P65 acetyla⁃tion on lysine 310,which is mediated by NAD-dependent protein deacetylase sirtuin-1 and is critical for NF-kB activation,were inhibited by glycolytic inhibitors.A coculture study revealed that 2-DG reduced the cytotoxicity of activated microglia toward MES23.5 dopaminergic neuron cells with no direct protective effect.In vivo,2-DG significantly ameliorated MPTP or LPS induced DA neuron loss and glial cell activation.CONCLUSION Glycolysis is actively involved in microglial activation.Inhibition of glycolysis can ameliorate microglial activation-related neuroinflammatory diseases.展开更多
基金supported by the National Natural Science Foundation of China(82071249 and 81771207).
文摘Objective:Neuropathic pain(NP)is one of the most common forms of chronic pain,yet current treatment options are limited in effectiveness.Peripheral nerve injury activates spinal microglia,altering their inflammatory response and phagocytic functions,which contributes to the progression of NP.Most current research on NP focuses on microglial inflammation,with relatively little attention to their phagocytic function.Early growth response factor 2(EGR2)has been shown to regulate microglial phagocytosis,but its specific role in NP remains unclear.This study aims to investigate how EGR2 modulates microglial phagocytosis and its involvement in NP,with the goal of identifying potential therapeutic targets.Methods:Adult male Sprague-Dawley(SD)rats were used to establish a chronic constriction injury(CCI)model of the sciatic nerve.Pain behaviors were assessed on days 1,3,7,10,and 14 post-surgery to confirm successful model induction.The temporal and spatial expression of EGR2 in the spinal cord was examined using real-time quantitative PCR(RT-qPCR),Western blotting,and immunofluorescence staining.Adeno-associated virus(AAV)was used to overexpress EGR2 in the spinal cord,and behavioral assessments were performed to evaluate the effects of EGR2 modulation of NP.CCI and lipopolysaccharide(LPS)models were established in animals and microglial cell lines,respectively,and changes in phagocytic activity were measured using RT-qPCR and fluorescent latex bead uptake assays.After confirming the involvement of microglial phagocytosis in NP,AAV was used to overexpress EGR2 in both in vivo and in vitro models,and phagocytic activity was further evaluated.Finally,eukaryotic transcriptome sequencing was conducted to screen differentially expressed mRNAs,followed by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses to identify potential downstream effectors of EGR2.Results:The CCI model successfully induced NP.Following CCI,EGR2 expression in the spinal cord was upregulated in parallel with NP development.Overexpression of EGR2 via spinal AAV injection enhanced microglial phagocytic activity and increased pain hypersensitivity in rats.Both animal and cellular models showed that CCI or LPS stimulation enhanced microglial phagocytosis,which was further amplified by EGR2 overexpression.Transcriptomic analysis of spinal cord tissues from CCI rats overexpressing EGR2 revealed upregulation of numerous genes associated with microglial phagocytosis and pain regulation.Among them,Lag3 emerged as a potential downstream target of EGR2.Conclusion:EGR2 contributes to the maintenance of NP by enhancing microglial phagocytosis in the spinal dorsal horn.
基金National Natural Science Foundation of China(8146055681760658)+2 种基金Foundation for High-level Innovative Talents of Guizhou Province(20164027)Innovation Research Group Projectof Education Department of Guizhou Province(2016038)Foundation for ExcellentYoung
文摘OBJECTIVE Neuroinflammation is considered to be an important and inevitable pathological process associated with all types of damages to the central nervous system.The hallmark of neuroinflammation is the microglia activation.In response to different micro-environmental disturbances,microglia could polarize into either an M1 pro-inflammatory phenotype,exacerbating neurotoxicity,or an M2 anti-inflammatory phenotype,exerting neuroprotection.Therefore,shifting the polarization of microglia toward the M2 phenotype could possess a more viable strategy for the neuroinflammatory disorders treatment.Naringenin(NAR) is natural y a grapefruit flavonoid and possesses various kinds of pharmacological activities,such as anti-inflammatory and neuroprotective activities.In the present study,we aimed to investigate the potential effects of NAR on microglial M1/M2 polarization and further reveal the underlying mechanisms of actions.METHODS BV-2 cells were pretreated with NAR(100 μmol·L^(-1)) for 1 h and then incubated with LPS(1 mg·L^(-1)) for 24 h.The effects of NAR on LPS-induced microglia activation,microglial M1/M2 polarization and MAPK pathways were detected.In addition,BV-2 cells were incubated with or without anisomycin(ANI,a selective agonist of JNK) to evaluate the role of JNK on microglia activation and microglia M1/M2 polarization.RESULTS First,NAR inhibited LPS-induced microglial activation.Then,NAR shifted the M1 pro-inflammatory microglia phenotype to the M2 anti-inflammatory M2 microglia state as demonstrated by the decreased expression of M1 markers,ie,inducible tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and the elevated expression of M2 markers(ie,arginase 1,IL-4 and IL-10).In addition,the effects of NAR on microglial polarization was dependent on MAPK signaling,particularly JNK inactivation,as evidenced by the fact that the selective activator of JNK abolished NAR-promoted M2 polarization and further NAR-inhibited microglial activation.CONCLUSION NAR promotes microglia M1/M2 polarization,thus conferring anti-neuroinflammatory effects via the inhibition of MAPK signaling activation.These findings might provide new alternative avenues for neuroinflammation-related disorders treatment.
基金The project supported by National Natural Science Foundation of China(81373384)
文摘OBJECTIVE Inhibition of phosphodiesterase 4(PDE4) improves the learning and memory abilities in Alzheimer disease animal models. The cognition-enhancing effects of PDE4 inhibition involve reduced inflammatory responses in the brain. However,the underlying mechanisms are illunderstood. cA MP induces autophagy,and deficiency of autophagy leads to elevated inflammatory factors.In the present study,we aimed to investigate the contribution of autophagy to the anti-inflammatory effect of PDE4 inhibitor ROF. METHODS Acidic vesicles were traced by Lysotracker(LYT) red and acridine orange(AO) staining. Autophagosomes in BV-2 cells was observed by immunofluorescence staining of microtubule-associated protein 1 light chain 3(LC3). Aβ_(25-35) or lipopolysaccharide(LPS) with ATP were used to activate microglial cells and inflammasome. Cytokine levels were measured by ELISA method. The levels of pro-inflammatory factors and essential proteins involved in the formation of autophagosome were detected by Western blotting. RESULTS ROF increased the level of LC3-Ⅱ,while the level of p62 was decreased. Enhanced fluorescent signals were observed in BV-2 cells treated with ROF by AO and LYT red staining. In addition,immunofluorescence indicated a significant increase in punctate LC3. Both LPS plus ATP and Aβ_(25-35) enhanced the conversion of pro-caspase-1 to cleaved-caspase-1 and increased the production of mature IL-1β. Interestingly,these effects were blocked by the treatment of ROF. Moreover,ROF decreased the apoptosis of neuronal N2 a cells in conditioned media from BV-2 microglia. These effects were reversed by inhibition of microglial autophagy.Treatment with ROF also showedenhanced autophagy in mcie treated with LPS. CONCLUSION PDE4 inhibitor ROF inhibits inflammasome activities and reduces the release of IL-1β by inducing autophagy.
基金National Natural Science Foundation of China(8163000388).
文摘OBJECTIVE Microglia-mediated dis-placement of synapses has been reported in the setting of experimental neuroinflammation,but its role in neurological disorders is poorly understood.Complex febrile seizures(FS)are the most common infantile seizures,yet its pathological progress is largely unknown.METHODS Mice pups(postnatal 8-10 d)were posted to 43℃hyperthermia condition to develop FS,and then the latency and threshold of seizures were determined.The displacement of synapses was observed through immunofluorescence staining.We researched whether microglial displacement of GABAergic synapses will influence complex FS-induced increase in GABAergic neurotransmission and neuronal excitability with patch-clamp electrophysiology.Moreover,we used the CD11 bD TR mice to selective ablation of microglia or pharmacological inhibition of microglia to observe their effects on susceptibility to FS and synaptic stripping.RESULTS GABAergic presynaptic terminals surrounding neuronal soma and GABAergic transmissions were increased in complex FS.Meanwhile,the activated microglia ensheathe glutamatergic neuronal soma to displace,but do not phagocytize,GABAergic presynaptic terminals.Patch-clamp electrophysiology established that the microglial displacement of GABAergic synapses reduced complex FS-induced increase in GABAergic neurotransmission and neuronal excitability,while GABA exerts excitatory action in this immature stage.Moreover,pharmacological inhibition of microglial displacement of GABAergic synapses or selective ablation of microglia in CD11 bDTR mice promoted the generation of complex FS.CONCLUSION Displacement of GABAergic synapses by microglia is a protective event in the pathological progress of complex FS.
基金Fundamental Research Funds for the Central Universities (20720180042)Health Science ResearchPersonnel Training Program of Fujian Province(2018-CXB-30)+2 种基金Natural Science Foundation of Fujian Province of China (2016J014152016D024)Science and Technology Pro
文摘OBJECTIVE Oleoylethanolamide(OEA) has shown neuroprotective effect in treating acute and chronic ischemic stroke.However,it is unclear whether OEA is able to modulate microglia/macrophage polarization,which has recently been documented to be important in the pathology of ischemic stroke.This study explored the potential role of OEA in modulating the microglial phenotypes.METHODS In vivo,middle cerebral artery occlusion(MCAO) was induced in both PPARα-/-(KO) and wild-type(WT)mice.In vitro,primary cortical microglia or neuron or coculture from KO/WT mice was subjected to oxygen glucose deprivation(OGD).Western blotting and immunofluorescence were used for detecting the specialized protein expression of M1/M2,such as CD206 and CD16/32.q PCR was utilized to detect the signature gene change of M1/M2.RESULTS OEA significantly reduced neuron damage of mice after MCAO.More importantly,OEA promoted microglia/macrophage transferring from inflammatory M1 phenotype to a protective,anti-inflammatory M2 phenotype in vivo or in vitro.Interestingly,these benifical effects of OEA could not be observed in the KO mice or KO microglia.CONCLUSION Our results reveal a novel pharmacological effect of OEA in modulating microglia/macrophage polarization after MCAO,thus depening our understanding of neuroprotective mechanisms of OEA in treatment of ischemic stroke.Furthermore,this new mechanism may allow OEA to be used in many other microglia/macrophage polarizationrelated inflammatory diseases.
基金National Key Research and Development Program(2016YFC1306301).
文摘OBJECTIVE To establish an in vitro cel model based on patient-specific human microglia to study the pathological mechanism of Alzheimer disease(AD) and to screen candidate drugs.METHODS First,the induced pluripotent stem cells(iPSCs) of AD patients and cognitive normal controls(CNC) were induced to hematopoietic progenitor cells(HPCs),and then HPCs were further induced with IL-34,M-CSF,GM-CSF and TGF-β1 for 20 d to obtain microglialike cells(MGLCs).HPCs were isolated by flow cytometry and MGLCs were identified by immunofluorescence.Cell phagocytosis was determined by phagocytosis neutral red experiusing Luminex assay kits,and the cell growth curve during the experiment was recorded by IncuCyte ZOOM.The phagocytic ability and secretion of cytokines of MGLCs were observed under the stimulation of LPS.RESULTS MGLCs from AD patients(AD-MGLCs) and CNC expressed microglia markers IBA1,TMEM119,P2 RY12,TREM2 and CD11 B.The results of phagocytosis neutral red experiment showed that under normal conditions,AD-MGLCs had stronger phagocytic ability(P<0.01).Stimulation by LPS resulted in increased phagocytosis of cel s,and the increase in phagocytosis of CNC-MGLCs was higher than AD-MGLCs(P<0.01).Experiments showed that high concentrations of LPS(>2 mg·L^(-1)) resulted in CNC-microglia death(P<0.01),whereas ADMGLCs did not show significant death.The cytokine assay showed that under normal conditions,the concentrations of IFN-γ and IL-2 secreted by AD patients were slightly higher than those of CNC.After LPS stimulation,the secretion of TNF-α,IL-6 and IL-10 was significantly increased.The increased secretion of AD-MGLCs was greater than that CNC-MGLCs(P<0.01).CONCLUSION AD-iPSCs derived MGLCs exhibit significant inflammatory characteristics and are more active than CNC,which may be associated with chronic inflammatory responses caused by microglia in AD,thus may provide valuable new tools to screen candidate drugs for the disease and to discover the mechanisms underlying AD pathogenesis.
基金National Natural Science Foundation of China(81760658).
文摘OBJECTIVE To investigate the protective effect of icariin(ICA) on lipopolysaccharide(LPS)-induced BV2 microglia injury,and to clarify the role of nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway in BV2 microglia-mediated neuroinflammation.METHODS BV2 microglia were randomly divided into control,ICA(0.1 μmol·L^(-1)),LPS(1 mg·L^(-1)),LPS + ICA(0.01 μmol·L^(-1)),and LPS + ICA(0.1 μmol·L^(-1))groups.BV2 microglia were treated with ICA for 30 min and then treated with LPS for 24 h.MTT assay was used to determine the cells survival rate,Griess kit and ELISA kits were used to detect the contents of NO,IL-1β and IL-18 in the culture supernatant,Western blotting was used to detect the expression of Nrf2,HO-1 and NQO1.Real time RT-PCR was used to detect the expression of Nrf2,HO-1 and NQO1 after ICA addition for 2,6 and 24 h.And immunofluorescence was used to observe the activation of Nrf2.RESULTS ICA reduced LPS-induced NO,IL-1β and IL-18 production in the culture supernatant,and ICA increase LPS-induced mRNA and protein expression of Nrf2 signaling pathway.CONCLUSION ICA protects LPS induced neuroinflammation by regulating Nrf2 signaling pathway.
基金National Natural Science Foundation of China(81373382,81773702,81130023)PriorityAcademic Program Development of JiangsuHigher Education Institutes (PAPD).
文摘OBJECTIVE Pleckstrin homologylike domain family A member 1(PHLDA1),also known as TDAG51,was first identified as a potential transcription factor required for Fas expression and activation-induced apoptosis in mouse T cell hybridomas.Subsequent research showed that PHILDA1 plays crucial roles in cell proliferation and apoptosis,PHLDA1 deficiency caused several phenotypic changes in macrophages that increased cytoprotection against oxidative and endoplasmic reticulum(ER) stress.However,little is known about the critical role of PHLDA1 in the neuroinflammation and neuronal apoptosis.METHODS Mouse Parkinson disease(PD) model was induced by intraperitoneal injection(ip) of MPTP for 7 d.Immunohistofluorescence staining was used to observe TH,Iba-1 and PHLDA1 in brain slides.Primary microglia and BV2 microglial cell lines were exposed to lipopolysacchrides(LPS) at different time points to determine PHLDA1 mRNA and protein level in vitro.BV2 cells with PHLDA1 knockdown using lentivirus experessing shRNA were exposed to LPS for the detection of proinflammatory genes expression by q-PCR or Western blotting.The NF-κB and MAPK pathways were detected to reveal the underlying mechanisms of PHLDA1 regulate microglia activation.Furthermore,to determine the effect of PHLDA1 deletion in the substantia nigra(SN) on motor dysfunction,the mice were previously infected with AAV-GFP(control) or AAV-shP HLDA1 in the SN in PD model,then were administered with behavior assessment.RESULTS PHLDA1 was expressed in microglia.PHLDA1 was increased in primary microglia or BV2 microglia cell lines by LPS treatment,acted as a positive regulator of TLR4 signaling.PHLDA1 deficiency suppressed LPS-induced microglia activation.The underlying mechanisms of PHLDA1 might be through directly interacting with TRAF6 to promote its auto-ubiquitination consequently enhanced neuroinflammatory.In PD model,PHLDA1 deletion in the SN limits microglial activation and protects dopaminergic neurons.PHLDA1 deficiency mice have a good behavioral score.CONCLUSION PHLDA1 deficiency in SN limits microglial inflammatory responses and protects dopaminergic neurons through attenuating auto-ubiquitination of TRAF6 in PD model.
基金supported by National Natural Science Foundation of China(81671188)Zhejiang Provincial Natural Science Foundation of China(LY12H31010)the Key Laboratory of Hangzhou City Project(20090233T12)
文摘OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine microglial morphological changes and the upstream molecular underlying IL^(-1)β production in Cys LT receptor agonist leukotriene D4(LTD4)-treated BV2 microglia in vitro.METHODS Twenty-four hours after murine microglial BV2 cells were stimulated with LTD4(1-100 nmol·L^(-1)),the cell proliferation and morphology were observed.The expression level of cysteinyl aspartate-specific protease 1(CASP1) protein was measured by Western blotin BV2 cells.In addition,BV2 cells were pretreated with or without CysLT1 receptor antagonist montelukast for 1 h and the effects of monte-lukaston LTD4-stimulated microglial activation and CASP1 expression were evaluated.RESULTS The number of BV2 cells had an increasing tendency after 24 h treatment with LTD4,but no significant differences were observed between the control and LTD4-treated cells(P>0.05).Under basal and resting conditions,BV2 microglial cells displayed a ramified morphology.However,LTD4 at 100 nmool·L^(-1) drove microglial morphological changes from a ramified towards an amoeboid shape.The expression of CASP1 protein was significantly upregulated in 100 nmool·L^(-1) LTD4-treated BV2 microglia(P<0.01).Furthermore,pretreatment with CysLT1 receptor antagonist montelukast prevented cell morphological changes and suppressed the increased CASP1 expression in LTD4-treated BV2 cells(P<0.05).CONCLUSION Cys LT receptor agonist LTD4 induces morphological changes and CASP1 expressionin BV2 microglia,which can be inhibited by CysLT1 antagonist.These results suggest the involvement of Cys LT signaling in microglial morphological changes and CASP1 expression.
基金The project supported by National Natural Science Foundation of China(81274119)
文摘OBJECTIVE Microglial activation contributes to neuroinflammation and neuronal damages in neurodegenerative disorders including Alzheimer and Parkinson diseases.It has been suggested that neurodegenerative disorders may be improved if neuroinflammation can be controlled.Isoliquiritigenin(ISL)isolated from Glycyrrhiza glabra possess potent anti-inflammatory capability,we thus investigate the inhibitory effects of ISL on LPS-induced microglial activation and neuroinflammation and the roles of neuroprotection on neurodegenerative disorders.Moveover,we would explore the mechanism of itsassociated inflammatory signaling passway.METHODS By cultivating,isolating and purifying,we got the primary microglia of the rat.The form of those cells was observed under an optical microscope,the purity was identified by the CD11b immunefluorescence staining.Firstly,the effects of ISL on microglial viability were explored by the MTT assay.The microglial cells were pretreated by ISL(5μmol·L-1)and then stimulated by LPS(100 ng·mL-1),the production of NO was detected by Griess reagent,the change of microglial morphology was observed by immunefluorescence staining.The production of IL-1βand TNF-αin culture medium were tested by ELISA,and the m RNA expression of pro-inflammatory factors,including IL-1β,TNF-α,i NOS and COX-2 was detected by real time PCR.The protein expression of i NOS and COX-2was detected by Western blotting.RESULTS(1)After purifying,microglial showed the typical morphological characteristics.The cell body was small,protruding outstretched in the branch rod,spindle.After LPS stimulation,the shape was changed to amoeba-like,and the protrusions retracted,cell rounding.In the CD11b immunefluorescence staining,the purity of the microglial was over 98%,and showed powerful phagocytic activity.(2)The results show that ISL(0.16-20μmol·L-1)concentration has no effect on primary microglia′s vitality.And at the concentration of 5μmol·L-1ISL has the significantly inhibitory effect on NO production induced by LPS.(3)The results shows that ISL pretreatment can significantly inhibit LPS-induced microglial activation,and can significantly reduce the production of NO in a dose-dependent manner(P<0.05).When stimulated by LPS for12 h,the expression of TNF-αand IL-1βm RNA in the culture medium are reduced by ISL pre-treatment(P<0.05).After LPS stimulation for 24 h,the expression of COX2 and i NOS m RNA and protein can be reduced(P<0.05).After stimulated by LPS from 0.5 to 2 h,p-ERK expression has be decreased.CONCLUSION We successfully obtain primary microglia with high-purity by culturing in vitro.We find that ISL can significantly reduce the levels of proinflammatory facters,which indicate ISL can inhibit microglia activation and neuroinflammation by blocking ERK1/2 signal pathway.
文摘OBJECTIVE Brain inflammation plays an important role in the pathophysiology of brain ischemicstroke,psychiatric and neurological diseases.During brain inflammation,microglia cells are activated and show pro-inflammatory M1 and anti-inflammatory M2 phenotypes,producing neurotoxic molecules and neurotrophic factors,respectively.We have previously discovered a novel natural product compound 3c exhibiting antiinflammatory effects in microglia cells,but the underlying mechanisms and its beneficial effects on brain inflammation and brain ischemia are unknown.METHODS The gene expression of M1 markers and M2 markers was measured by RT-PCR.The AMPK phosphorylation level and M2 marker CD206 protein expression were determined by Western blotting.TNFαrelease was measured by ELISA.The gene knowdown was performed by the si RNA transfection experiment.The LPS-induced brain inflammation mouse model and transient middle cerebral artery occlusion(t MCAO)stroke model were used.RESULTS We found that compound 3c inhibited M1polarization and promoted M2 polarization in LPS-stimulated BV2 and primary microglia cells,and these effects are mediated by Ca MKKβ/AMPK/JNK signaling pathway.Furthermore,compound 3c prevented M1 gene expression and enhanced M2 gene expression in a mouse model of LPS-induced neuroinflammation,and reduced the LPS-induced sickness behavior.In addition,compound 3c significantly reduced infarct volume,improved the neurological deficit,and reduced neuroinflammation in rats with acute focal cerebral ischemia.CONCLUSION Our results indicate that natural product compound 3c suppresses microglia activation by promoting M2 polarization and may provide a novel therapeutic approach to treat brain ischemic stroke associated with enhanced brain inflammation.
文摘Microglia activation induced neuroinflammation closely relates with the development of Parkinson disease. Autophagy regulates many biological processes,but the role in microglial activation and the development of Parkinson disease is not clear. In this study,we show that loss of microglial Atg5 cause neuroinflammation and motor and cognitive learning impairment in mice,with accumulation of α-synuclein and decrease of dopamine levels in the striatum. Inhibition of autophagy aggravates the activation of NLRP3 inflammasome via PDE10a-cAMP signaling in microglia. Furthermore,the downstream cytokine IL-1 increases Mif levels in a transcriptional dependent manner. Interestingly,Mif levels are significantly elevated in Parkinson disease patients. Taken together,our results reveal a protective role of autophagy in microglial activation-driven Parkinson disease,thus providing a potential targets for the clinical treatment.
文摘Aim Brain inflammation plays an important role in the pathophysiology of many psychiatric and neuro- logical diseases. Angiotensin II type 1 receptor blockers （ARBs） ameliorate brain inflammation and reduce M1 mi- croglia activation. The ARB telmisartan suppresses neuroinflammation in cultured neuronal cells. We wished to clarify whether telmisartan prevents microglia-mediated neuroinflammation through microglia polarization to an anti- inflammatory M2 phenotype. Methods The gene expression of M1 markers and M2 markers was measured by RT- PCR. The AMPK phosphorylation level and M2 marker CD206 protein expression were determined by Western blot. TNF-α and IL-10 release was measured by ELISA. The gene knowdown was performed by the siRNA transfec- tion experiment. Results Our results demonstrated that telmisartan promoted M2 polarization in LPS-stimulated BV2 and primary microglia cells. The promoting effects of telmisartan on M2 polarization were attenuated by an AMP-activated protein kinase （AMPK） inhibitor or AMPK knockdown, indicating that AMPK activation partici- pates on telmisartan effects. Furthermore, telmisartan enhanced brain AMPK activation and M2 gene expression in a mouse model of LPS-induced neuroinflammation. Conclusion Our results indicate that telmisartan can be con- sidered as a novel AMPK activator, suppressing neuroinflammation by promoting microglia M2 polarization. Telmis- artan may provide a novel and safe therapeutic approach for the treatment of brain disorders associated with neuroin- flammation.
文摘Aim p53 up-regulated modulator of apoptosis （PUMA） is a known apoptosis inducer; however its role in microglial survival remains poorly understood. In addition to the classical transcription factor p53, microRNA- 143 （miR-143） is involved in PUMA expression at the post-transcriptional level. Furthermore, they identify unique roles of miR-143/PUMA in mediating microglial survival via the regulation of apoptosis and autophagy interplay. Results Blockage of autophagy accelerated methamphetamine-induced apoptosis, whereas the induction of autoph- agy attenuated the decrease in microglial survival. Moreover, anti-miR-143-dependent PUMA up-regulation re- versed the methamphetamine-induced decrease in microglial survival via the regulation of apoptosis and autophagy. The in vivo relevance of these findings was confirmed in mouse models, which demonstrated that the microinjection of anti-miR-143 into the hippocampus ameliorated the methamphetamine-induced decrease in microglia as well as that observed in heterozygous miR-143 ^＋/- mice. Conclusion These findings provided new insight for the specific contributions of miR-143/PUMA to microglial survival in the context of drug abuse.
文摘Microglia are the principal immune effectors in central nervous system and plays an extremely important role in the central nervous system disease. Under physiological conditions, resting state microglia plays a role of nu- trition, support and protection of neurons. Interestingly, recent studies have revealed that resting microglia processes make brief and direct contacts with neuronal synapses at a frequency of about once per hour and through these con- tacts monitoring the function and state of the synapses, providing the brain with a dynamic and efficient monitoring system. Microglia can be quickly activated and proliferated after cerebral ischemia. It exerts dual effects by produ- cing neurotoxic molecules and neurotrophic factors. Therefore, studying the relationship between brain ischemia in- jury and microglia, give full play to its protective function and reduce its damage, will shed a light on the treatment of cerebral ischemia.
文摘Aim Following cerebral isehemia, microglia respond to the injury acting as the first defense of central nervous system. Activated microglia play a dual role in the ischemie injury depending on the phenotype of micro- gila, including deleterious M1 phenotype and neuroprotective M2 phenotype. However, microglia show transient M2 phenotype followed by a transition to M1 phenotype aggravating the ischemic injury. Many signal pathways par- ticipate in the modulation of microglial polarization , presenting potential therapeutic targets for selectively inducing the polarization of M2 microglia. In this review, we discuss M2 microglia phenotype mediated neuroprotective role and the signaling cascades controlling microglial phenotype after ischemic stroke.
文摘Aim Aconitine and its structurally-related diterpenoid alkaloids have been shown to interact differential- ly with neuronal voltage-dependent sodium channels and be responsible for their analgesia and toxicity. Bulleya- conitine A （ BAA or BLA） is an aconitine analog and has been prescribed for the management of pain. The present study aimed to evaluate the inhibitory effects of BAA on pain hypersensitivity and morphine anti-nociceptive toler- ance, and explore whether the release of dynorphin A from spinal microglia was associated with its mechanism of actions. Methods Rat models of neuropathic pain, formalin test and bone cancer pain were used, and spinal dynorphin A level and expression were measured. Sample size of animals was six in each study group. Resultes A single intrathecal or subcutaneous （but not intraventricular or local） injection of BAA blocked spinal nerve liga- tion-induced painful neuropathy, bone cancer-induced pain and formalin-induced hyperalgesia by 60% - 100% with the ED50 values of 94 - 126 ng/rat （intrathecal） and 42 - 59 μg · kg^-1 （ subcutaneous）, respectively. Follow- ing chronic treatment, BAA did not induce either self-tolerance to anti-nociception or cross-tolerance to morphine anti-nociception, and completely prevented morphine tolerance. Spinal BAA anti-nociception, but not neurotoxici- ty, was completely blocked by the specific microglial inhibitor minocycline. In a minocycline-sensitive and lido- BAA stimulated the release of dynorphin A from the spinal cord, and the caine- or ropivacaine-insensitive manner, primary culture of microglia but not from neurons or astrocytes. The blockade effects of BAA on nociception and morphine tolerance were completely blocked by the specific dynorphin A antiserum and/or K-opioid receptor antago- nist. Conclusions Our results demonstrated that BAA eliminated pain hypersensitivity and morphine tolerance through the direct stimulation of dynorphin A release from spinal microglia, which was not dependent on the interac- tions with sodium channels.
基金Natural science foundation of Hebei Province(H2020405298)。
文摘OBJECTIVE To establish an in vitro inflammatory model of BV2 by observing the activity,the release amount of NO and the expression of inflammatory factors of microglial cells(BV2)induced by lipopolysaccharides(LPS).METHODS BV2 was routinely cultured in vitro.Cell viability was measured by CCK-8 meth⁃od.And by drew cell growth curve to determine the logarithmic growth cycle of the cells.After 24 h of routine culture,BV2 were induced by adding different concentrations of LPS(0.1,1.0 and 10.0 mg·L-1)for 4,8,12,24 and 48 h,respectively.Meanwhile,the morphological changes of BV2 were observed under inverted microscope to compare the activation degree of microglia at dif⁃ferent time and concentration.Cell activity and nitric oxide(NO)level were determined by CCK-8 and Griess method respectively,which could help to determine the optimal concentration and time of modeling.Finally,It were determined by ELISA that the concentrations of tumor necrosis factorα(TNF-α),interleukin-6(IL-6)and IL-1βin supernatant of LPS 1 mg·L-1 culture for 24 h.RESULTS BV2 were in logarithmic growth phase for 1 to 3 d after subculture.LPS 1 mg·L-1 induced BV2 for 24 or 48 h which could increase the release amount of NO significantly(P<0.05).In order to save time,LPS induced BV2 for 24 h were selected for subsequent experiments.Microglial cells in resting state were observed to be elongated spindle shape under inverted micro⁃scope.After LPS activation,the cell body became larger and the branching processes shrank back,presenting an amoeba-like appearance.ELISA results showed that the concentrations of TNF-α,IL-6 and IL-1βin supernatant of LPS 1 mg·L-1 cultured for 24 h were significantly increased which compared with the control group(P<0.05).CONCLUSION LPS could induce the activation of BV2 and up-regulate the level of inflammatory factors.The optimal condition for establishing stable BV2 microglial inflammatory model was used LPS 1 g·L-1 induced for 24 h.
文摘OBJECTIVE Microglial activation-mediated neuroinflammation plays an important pathological basis in the progression of many neurodegenerative diseases.Activated microglia cells show a metabolic shift from oxidative phos⁃phorylation to aerobic glycolysis.However,the molecular mechanism underlying the role of glycolysis in microglial activation and progres⁃sion of neuroinflammatory diseases have not yet been fully understood.METHODS The anti-inflammatory effects and its underlying mecha⁃nisms of glycolytic inhibition in vitro were exam⁃ined in lipopolysaccharide(LPS)activated BV-2 microglial cells or primary microglial cells by enzyme-linked immunosorbent assay(ELISA),quantitative reverse transcriptase polymerase chain reaction(RT-PCR),Western blotting,immunoprecipitation,Flow cytometry and nuclear factor kappa B(NF-κB)luciferase reporter assays.In vivo,the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-or LPS-induced Par⁃kinson disease(PD)models were constructed to explored the anti-inflammatory and neuropro⁃tective effects of glycolytic inhibitor.RESULTS Inhibition of glycolysis by specific inhibitors[2-DG and 3-bromopyruvic acid(3-BPA)],knockdown of glucose transporter type 1(Glut-1)or hexoki⁃nase(HK)Ⅱabolished LPS-induced expres⁃sion of proinflammatory genes in microglia cells.Mechanistic studies demonstrated that glyco⁃lytic inhibitors significantly inhibited LPS-induced mTOR phosphorylation,IKKβphosphorylation,IκB phosphorylation,IκB degradation,nuclear translocation of P65 and NF-κB luciferase activity.Furthermore,LPS-induced P65 acetyla⁃tion on lysine 310,which is mediated by NAD-dependent protein deacetylase sirtuin-1 and is critical for NF-kB activation,were inhibited by glycolytic inhibitors.A coculture study revealed that 2-DG reduced the cytotoxicity of activated microglia toward MES23.5 dopaminergic neuron cells with no direct protective effect.In vivo,2-DG significantly ameliorated MPTP or LPS induced DA neuron loss and glial cell activation.CONCLUSION Glycolysis is actively involved in microglial activation.Inhibition of glycolysis can ameliorate microglial activation-related neuroinflammatory diseases.
