Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mamm...Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and characterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitters that mediate many diverse cellular processes within the central nervous system.While our understanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.展开更多
Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mamm...Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and chara cterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitte rs that mediate many diverse cellular processes within the central nervous system.While our unde rstanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.展开更多
An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease prog...An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.展开更多
Purinergic signalling,adenosine 5′-triphosphate（ATP）as an extracellular signalling molecule,was proposed in 1972（Burnstock,1972）.However,it was not generally accepted until the early 1990s when receptors for ATP ...Purinergic signalling,adenosine 5′-triphosphate（ATP）as an extracellular signalling molecule,was proposed in 1972（Burnstock,1972）.However,it was not generally accepted until the early 1990s when receptors for ATP and its breakdown product adenosine were cloned and characterised（Ralevic and Burnstock,1998）.Four P1（adenosine）receptors are recognised（A1,A2A,A2B and A3）.展开更多
Epilepsy is a neurological disorder caused by the pathological hyper-synchronization of neuronal discharges.The fundamental research of epilepsy mechanisms and the targets of drug design options for its treatment have...Epilepsy is a neurological disorder caused by the pathological hyper-synchronization of neuronal discharges.The fundamental research of epilepsy mechanisms and the targets of drug design options for its treatment have focused on neurons.However,approximately 30%of patients suffering from epilepsy show resistance to standard anti-epileptic chemotherapeutic agents while the symptoms of the remaining 70%of patients can be alleviated but not completely removed by the current medications.Thus,new strategies for the treatment of epilepsy are in urgent demand.Over the past decades,with the increase in knowledge on the role of glia in the genesis and development of epilepsy,glial cells are receiving renewed attention.In a normal brain,glial cells maintain neuronal health and in partnership with neurons regulate virtually every aspect of brain function.In epilepsy,however,the supportive roles of glial cells are compromised,and their interaction with neurons is altered,which disrupts brain function.In this review,we will focus on the role of glia-related processes in epileptogenesis and their contribution to abnormal neuronal activity,with the major focus on the dysfunction of astroglial potassium channels,water channels,gap junctions,glutamate transporters,purinergic signaling,synaptogenesis,on the roles of microglial inflammatory cytokines,microglia-astrocyte interactions in epilepsy,and on the oligodendroglial potassium channels and myelin abnormalities in the epileptic brain.These recent findings suggest that glia should be considered as the promising next-generation targets for designing anti-epileptic drugs that may improve epilepsy and drug-resistant epilepsy.展开更多
Chaigui granules(CG)are a compound composed of six herbal medicines with significant antidepressant effects.However,the antidepressant mechanism of CG remains unclear.In the present study,we attempted to elucidate the...Chaigui granules(CG)are a compound composed of six herbal medicines with significant antidepressant effects.However,the antidepressant mechanism of CG remains unclear.In the present study,we attempted to elucidate the antidepressant mechanism of CG by regulating purine metabolism and purinergic signaling.First,the regulatory effect of CG on purine metabolites in the prefrontal cortex(PFC)of chronic unpredictable mild stress(CUMS)rats was analyzed by ultra high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)targeted quantitative analysis.Meanwhile,purinergic receptors(P2X7 receptor(P2X7R),A1 receptor(A1R)and A2A receptor(A2AR))and signaling pathways(nod-like receptor protein 3(NLRP3)inflammasome pathway and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)pathway)associated with purine metabolism were analyzed by western blotting and enzyme-linked immunosorbent assay(ELISA).Besides,antidepressant mechanism of CG by modulating purine metabolites to activate purinergic receptors and related signaling pathways was dissected by exogenous supplementation of purine metabolites and antagonism of purinergic receptors in vitro.An in vivo study showed that the decrease in xanthine and the increase in four purine nucleosides were closely related to the antidepressant effects of CG.Additionally,purinergic receptors(P2X7R,A1R and A2AR)and related signaling pathways(NLRP3 inflammasome pathway and cAMP-PKA pathway)were also significantly regulated by CG.The results of exogenous supplementation of purine metabolites and antagonism of purinergic receptors showed that excessive accumulation of xanthine led to activation of the P2X7R-NLRP3 inflammasome pathway,and the reduction of adenosine and inosine inhibited the A1R-cAMP-PKA pathway,which was significantly ameliorated by CG.Overall,CG could promote neuroprotection and ultimately play an antidepressant role by inhibiting the xanthine-P2X7R-NLRP3 inflammasome pathway and activating the adenosine/inosine-A1R-cAMP-PKA pathway.展开更多
BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are...BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.展开更多
The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel di...The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel diseases(IBDs).IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine,and the symptoms of IBDs may include abdominal pain,diarrhea,rectal bleeding,and weight loss.The P2X7 receptor has become a promising therapeutic target for IBDs,especially owing to its wide expression and,in the case of other purinergic receptors,in both human and model animal enteric cells.However,little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine.In this review,an integrated view is provided,correlating the structural organization of the ENS and the effects of IBDs,focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.展开更多
Purinergic P2 receptors,activated by endogenous ATP,are prominently expressed on neuronal and nonneuronal cells during development of the auditory periphery and central auditory neurons.In the mature cochlea,extracell...Purinergic P2 receptors,activated by endogenous ATP,are prominently expressed on neuronal and nonneuronal cells during development of the auditory periphery and central auditory neurons.In the mature cochlea,extracellular ATP contributes to ion homeostasis,and has a protective function against noise exposure.Here,we focus on the modulation of activity by extracellular ATP during early postnatal development of the lower auditory pathway.In mammals,spontaneous patterned activity is conveyed along afferent auditory pathways before the onset of acoustically evoked signal processing.During this critical developmental period,inner hair cells fire bursts of action potentials that are believed to provide a developmental code for synaptic maturation and refinement of auditory circuits,thereby establishing a precise tonotopic organization.Endogenous ATP-release triggers such patterned activity by raising the extracellular K+concentration and contributes to firing by increasing the excitability of auditory nerve fibers,spiral ganglion neurons,and specific neuron types within the auditory brainstem,through the activation of diverse P2 receptors.We review recent studies that provide new models on the contribution of purinergic signaling to early development of the afferent auditory pathway.Further,we discuss potential future directions of purinergic research in the auditory system.展开更多
Viral encephalitis is a devastating disease with high mortality,and survivors often suffer from severe neurological complications.Microglia are innate immune cells of the central nervous system(CNS)parenchyma whose tu...Viral encephalitis is a devastating disease with high mortality,and survivors often suffer from severe neurological complications.Microglia are innate immune cells of the central nervous system(CNS)parenchyma whose turnover is reliant on local proliferation.Microglia express a diverse range of proteins,which allows them to continuously sense the environment and quickly react to changes.Under inflammatory conditions such as CNS viral infection,microglia promote innate and adaptive immune responses to protect the host.However,during viral infection,a dysregulated microglia-T-cell interplay may result in altered phagocytosis of neuronal synapses by microglia that causes neurocognitive impairment.In this review,we summarize the current knowledge on the role of microglia in viral encephalitis,propose questions to be answered in the future and suggest possible therapeutic targets.展开更多
Mounting evidence suggests that the ATP-gated P2X7 receptor contributes to increased hyperexcitability in the brain.While increased expression of P2X7 in the hippocampus and cortex following status epilepticus and dur...Mounting evidence suggests that the ATP-gated P2X7 receptor contributes to increased hyperexcitability in the brain.While increased expression of P2X7 in the hippocampus and cortex following status epilepticus and during epilepsy has been repeatedly demonstrated,the cell type-specific expression of P2X7 and its expression in extra-hippocampal brain structures remains incompletely explored.In this study,P2X7 expression was visualized by using a transgenic mouse model overexpressing P2X7 fused to the fluorescent protein EGFP.The results showed increased P2X7-EGFP expression after status epilepticus induced by intra-amygdala kainic acid and during epilepsy in different brain regions including the hippocampus,cortex,striatum,thalamus and cerebellum,and this was most evident in microglia and oligodendrocytes.Colocalization of P2X7-EGFP with cell type-specific markers was not detected in neurons or astrocytes.These data suggest that P2X7 activation is a common pathological hallmark across different brain structures,possibly contributing to brain inflammation and neurodegeneration following acute seizures and during epilepsy.展开更多
The P2X4 receptor(P2X4)is an ATP-gated cation channel that is highly permeable to Ca2+and widely expressed in neuronal and glial cell types throughout the central nervous system(CNS).A growing body of evidence indicat...The P2X4 receptor(P2X4)is an ATP-gated cation channel that is highly permeable to Ca2+and widely expressed in neuronal and glial cell types throughout the central nervous system(CNS).A growing body of evidence indicates that P2X4 plays key roles in numerous central disorders.P2X4 trafficking is highly regulated and consequently in normal situations,P2X4 is present on the plasma membrane at low density and found mostly within intracellular endosomal/lysosomal compartments.An increase in the de novo expression and/or surface density of P2X4 has been observed in microglia and/or neurons during pathological states.This review aims to summarize knowledge on P2X4 functions in CNS disorders and provide some insights into the relative contributions of neuronal and glial P2X4 in pathological contexts.However,determination of the cell-specific functions of P2X4 along with its intracellular and cell surface roles remain to be elucidated before its potential as a therapeutic target in multiple disorders can be defined.展开更多
基金supported by a Natural Sciences and Engineering Research Council operating grant(RGPIN-2019-07062).
文摘Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and characterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitters that mediate many diverse cellular processes within the central nervous system.While our understanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.
基金a Natural Sciences and Engineering Research Council operating grant(RGPIN-2019-07062)。
文摘Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and chara cterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitte rs that mediate many diverse cellular processes within the central nervous system.While our unde rstanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.
基金supported by a grant from Ministry of Science,Technological Development and Innovation,Serbia,No.451-03-68/2022-14/200178(to NN)University of Defence,No.MFVMA/02/22-24(to MN)。
文摘An imbalance in adenosine-mediated signaling,particularly the increased A_(2A)R-mediated signaling,plays a role in the pathogenesis of Parkinson's disease.Existing therapeutic approaches fail to alter disease progression,demonstrating the need for novel approaches in PD.Repetitive transcranial magnetic stimulation is a non-invasive approach that has been shown to improve motor and non-motor symptoms of Parkinson's disease.However,the underlying mechanisms of the beneficial effects of repetitive transcranial magnetic stimulation remain unknown.The purpose of this study is to investigate the extent to which the beneficial effects of prolonged intermittent theta burst stimulation in the 6-hydroxydopamine model of experimental parkinsonism are based on modulation of adenosine-mediated signaling.Animals with unilateral 6-hydroxydopamine lesions underwent intermittent theta burst stimulation for 3 weeks and were tested for motor skills using the Rotarod test.Immunoblot,quantitative reverse transcription polymerase chain reaction,immunohistochemistry,and biochemical analysis of components of adenosine-mediated signaling were performed on the synaptosomal fraction of the lesioned caudate putamen.Prolonged intermittent theta burst stimulation improved motor symptoms in 6-hydroxydopamine-lesioned animals.A 6-hydroxydopamine lesion resulted in progressive loss of dopaminergic neurons in the caudate putamen.Treatment with intermittent theta burst stimulation began 7 days after the lesion,coinciding with the onset of motor symptoms.After treatment with prolonged intermittent theta burst stimulation,complete motor recovery was observed.This improvement was accompanied by downregulation of the e N/CD73-A_(2A)R pathway and a return to physiological levels of A_(1)R-adenosine deaminase 1 after 3 weeks of intermittent theta burst stimulation.Our results demonstrated that 6-hydroxydopamine-induced degeneration reduced the expression of A_(1)R and elevated the expression of A_(2A)R.Intermittent theta burst stimulation reversed these effects by restoring the abundances of A_(1)R and A_(2A)R to control levels.The shift in ARs expression likely restored the balance between dopamine-adenosine signaling,ultimately leading to the recovery of motor control.
文摘Purinergic signalling,adenosine 5′-triphosphate（ATP）as an extracellular signalling molecule,was proposed in 1972（Burnstock,1972）.However,it was not generally accepted until the early 1990s when receptors for ATP and its breakdown product adenosine were cloned and characterised（Ralevic and Burnstock,1998）.Four P1（adenosine）receptors are recognised（A1,A2A,A2B and A3）.
基金supported by the Ministry of Education,Science and Technological Development of Republic of Serbia,Nos.451-03-68/2022-14/200007 and 451-03-68/2022-14/200053(to LN and JBP),Grants from European Commission(H2020 MSCA-ITN EU-GliaPhD No.72205)(to PN)Agence Nationale de la Recherche,Nos.ANR-19-CE16-0018-03 and ANR-20CE16-0003-02(to PN)+1 种基金Grants from Science and Technology Department of Zhejiang Province,China,No.2021RC051(to WS)Scientific Research Foundation for Returned Scholars of Hangzhou City,China,No.2019(to WS).
文摘Epilepsy is a neurological disorder caused by the pathological hyper-synchronization of neuronal discharges.The fundamental research of epilepsy mechanisms and the targets of drug design options for its treatment have focused on neurons.However,approximately 30%of patients suffering from epilepsy show resistance to standard anti-epileptic chemotherapeutic agents while the symptoms of the remaining 70%of patients can be alleviated but not completely removed by the current medications.Thus,new strategies for the treatment of epilepsy are in urgent demand.Over the past decades,with the increase in knowledge on the role of glia in the genesis and development of epilepsy,glial cells are receiving renewed attention.In a normal brain,glial cells maintain neuronal health and in partnership with neurons regulate virtually every aspect of brain function.In epilepsy,however,the supportive roles of glial cells are compromised,and their interaction with neurons is altered,which disrupts brain function.In this review,we will focus on the role of glia-related processes in epileptogenesis and their contribution to abnormal neuronal activity,with the major focus on the dysfunction of astroglial potassium channels,water channels,gap junctions,glutamate transporters,purinergic signaling,synaptogenesis,on the roles of microglial inflammatory cytokines,microglia-astrocyte interactions in epilepsy,and on the oligodendroglial potassium channels and myelin abnormalities in the epileptic brain.These recent findings suggest that glia should be considered as the promising next-generation targets for designing anti-epileptic drugs that may improve epilepsy and drug-resistant epilepsy.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.:82074323 and 81673572)Key Research and Development Program of Shanxi Province(Grant No.:202102130501010)+2 种基金Innovation Project for Graduate Students in Shanxi Province(Grant No.:2022Y162)the Major Science and Technology Project for“Significant New Drugs Creation”(Grant No.:2017ZX09301047)Research Project Supported by Shanxi Scholarship Council of China(Grant No.:2020019).
文摘Chaigui granules(CG)are a compound composed of six herbal medicines with significant antidepressant effects.However,the antidepressant mechanism of CG remains unclear.In the present study,we attempted to elucidate the antidepressant mechanism of CG by regulating purine metabolism and purinergic signaling.First,the regulatory effect of CG on purine metabolites in the prefrontal cortex(PFC)of chronic unpredictable mild stress(CUMS)rats was analyzed by ultra high-performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS)targeted quantitative analysis.Meanwhile,purinergic receptors(P2X7 receptor(P2X7R),A1 receptor(A1R)and A2A receptor(A2AR))and signaling pathways(nod-like receptor protein 3(NLRP3)inflammasome pathway and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)pathway)associated with purine metabolism were analyzed by western blotting and enzyme-linked immunosorbent assay(ELISA).Besides,antidepressant mechanism of CG by modulating purine metabolites to activate purinergic receptors and related signaling pathways was dissected by exogenous supplementation of purine metabolites and antagonism of purinergic receptors in vitro.An in vivo study showed that the decrease in xanthine and the increase in four purine nucleosides were closely related to the antidepressant effects of CG.Additionally,purinergic receptors(P2X7R,A1R and A2AR)and related signaling pathways(NLRP3 inflammasome pathway and cAMP-PKA pathway)were also significantly regulated by CG.The results of exogenous supplementation of purine metabolites and antagonism of purinergic receptors showed that excessive accumulation of xanthine led to activation of the P2X7R-NLRP3 inflammasome pathway,and the reduction of adenosine and inosine inhibited the A1R-cAMP-PKA pathway,which was significantly ameliorated by CG.Overall,CG could promote neuroprotection and ultimately play an antidepressant role by inhibiting the xanthine-P2X7R-NLRP3 inflammasome pathway and activating the adenosine/inosine-A1R-cAMP-PKA pathway.
基金Supported by the National Council for Scientific and Technological Development,No.168015/2018-8the São Paulo Research Foundation,No.2014/25927-2 and No.2018/07862-1.
文摘BACKGROUND The literature indicates that the enteric nervous system is affected in inflammatory bowel diseases(IBDs)and that the P2X7 receptor triggers neuronal death.However,the mechanism by which enteric neurons are lost in IBDs is unknown.AIM To study the role of the caspase-3 and nuclear factor kappa B(NF-κB)pathways in myenteric neurons in a P2X7 receptor knockout(KO)mouse model of IBDs.METHODS Forty male wild-type(WT)C57BL/6 and P2X7 receptor KO mice were euthanized 24 h or 4 d after colitis induction by 2,4,6-trinitrobenzene sulfonic acid(colitis group).Mice in the sham groups were injected with vehicle.The mice were divided into eight groups(n=5):The WT sham 24 h and 4 d groups,the WT colitis 24 h and 4 d groups,the KO sham 24 h and 4 d groups,and the KO colitis 24 h and 4 d groups.The disease activity index(DAI)was analyzed,the distal colon was collected for immunohistochemistry analyses,and immunofluorescence was performed to identify neurons immunoreactive(ir)for calretinin,P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,and total NF-κB.We analyzed the number of calretinin-ir and P2X7 receptor-ir neurons per ganglion,the neuronal profile area(μm^(2)),and corrected total cell fluorescence(CTCF).RESULTS Cells double labeled for calretinin and P2X7 receptor,cleaved caspase-3,total caspase-3,phospho-NF-κB,or total NF-κB were observed in the WT colitis 24 h and 4 d groups.The number of calretinin-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(2.10±0.13 vs 3.33±0.17,P<0.001;2.92±0.12 vs 3.70±0.11,P<0.05),but was not significantly different between the KO groups.The calretinin-ir neuronal profile area was increased in the WT colitis 24 h group compared to the WT sham 24 h group(312.60±7.85 vs 278.41±6.65,P<0.05),and the nuclear profile area was decreased in the WT colitis 4 d group compared to the WT sham 4 d group(104.63±2.49 vs 117.41±1.14,P<0.01).The number of P2X7 receptor-ir neurons per ganglion was decreased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(19.49±0.35 vs 22.21±0.18,P<0.001;20.35±0.14 vs 22.75±0.51,P<0.001),and no P2X7 receptor-ir neurons were observed in the KO groups.Myenteric neurons showed ultrastructural changes in the WT colitis 24 h and 4 d groups and in the KO colitis 24 h group.The cleaved caspase-3 CTCF was increased in the WT colitis 24 h and 4 d groups compared to the WT sham 24 h and 4 d groups,respectively(485949±14140 vs 371371±16426,P<0.001;480381±11336 vs 378365±4053,P<0.001),but was not significantly different between the KO groups.The total caspase-3 CTCF,phospho-NF-κB CTCF,and total NF-κB CTCF were not significantly different among the groups.The DAI was recovered in the KO groups.Furthermore,we demonstrated that the absence of the P2X7 receptor attenuated inflammatory infiltration,tissue damage,collagen deposition,and the decrease in the number of goblet cells in the distal colon.CONCLUSION Ulcerative colitis affects myenteric neurons in WT mice but has a weaker effect in P2X7 receptor KO mice,and neuronal death may be associated with P2X7 receptor-mediated caspase-3 activation.The P2X7 receptor can be a therapeutic target for IBDs.
基金Supported by the Sao Paulo Research (FAPESP, Brazil),No. 2014/25927-2 and No. 2018/07862-1the National Council for Scientific and Technological Development (CNPq, Brazil)
文摘The enteric nervous system(ENS)consists of thousands of small ganglia arranged in the submucosal and myenteric plexuses,which can be negatively affected by Crohn’s disease and ulcerative colitis-inflammatory bowel diseases(IBDs).IBDs are complex and multifactorial disorders characterized by chronic and recurrent inflammation of the intestine,and the symptoms of IBDs may include abdominal pain,diarrhea,rectal bleeding,and weight loss.The P2X7 receptor has become a promising therapeutic target for IBDs,especially owing to its wide expression and,in the case of other purinergic receptors,in both human and model animal enteric cells.However,little is known about the actual involvement between the activation of the P2X7 receptor and the cascade of subsequent events and how all these activities associated with chemical signals interfere with the functionality of the affected or treated intestine.In this review,an integrated view is provided,correlating the structural organization of the ENS and the effects of IBDs,focusing on cellular constituents and how therapeutic approaches through the P2X7 receptor can assist in both protection from damage and tissue preservation.
基金the Deutsche Forschungsgemeinschaft(DFG Grant 954/3-1)as a part of the priority program 1608“Ultrafast and temporally precise information processing:normal and dysfunctional hearing”。
文摘Purinergic P2 receptors,activated by endogenous ATP,are prominently expressed on neuronal and nonneuronal cells during development of the auditory periphery and central auditory neurons.In the mature cochlea,extracellular ATP contributes to ion homeostasis,and has a protective function against noise exposure.Here,we focus on the modulation of activity by extracellular ATP during early postnatal development of the lower auditory pathway.In mammals,spontaneous patterned activity is conveyed along afferent auditory pathways before the onset of acoustically evoked signal processing.During this critical developmental period,inner hair cells fire bursts of action potentials that are believed to provide a developmental code for synaptic maturation and refinement of auditory circuits,thereby establishing a precise tonotopic organization.Endogenous ATP-release triggers such patterned activity by raising the extracellular K+concentration and contributes to firing by increasing the excitability of auditory nerve fibers,spiral ganglion neurons,and specific neuron types within the auditory brainstem,through the activation of diverse P2 receptors.We review recent studies that provide new models on the contribution of purinergic signaling to early development of the afferent auditory pathway.Further,we discuss potential future directions of purinergic research in the auditory system.
基金Open Access funding enabled and organized by Projekt DEAL.M.P.was supported by the Sobek Foundation,the Ernst-Jung Foundation,the DFG(SFB 992,SFB1160,SFB/TRR167,Reinhart-Koselleck-Grant,and Gottfried Wilhelm Leibniz-Prize)and the Ministry of Science,Research and Arts,Baden-Wuerttemberg(Sonderlinie“Neuroinflammation”).This study was supported by the DFG under Germany’s Excellence Strategy(CIBSS-EXC-2189-Project ID390939984).The figures were created with BioRender.com。
文摘Viral encephalitis is a devastating disease with high mortality,and survivors often suffer from severe neurological complications.Microglia are innate immune cells of the central nervous system(CNS)parenchyma whose turnover is reliant on local proliferation.Microglia express a diverse range of proteins,which allows them to continuously sense the environment and quickly react to changes.Under inflammatory conditions such as CNS viral infection,microglia promote innate and adaptive immune responses to protect the host.However,during viral infection,a dysregulated microglia-T-cell interplay may result in altered phagocytosis of neuronal synapses by microglia that causes neurocognitive impairment.In this review,we summarize the current knowledge on the role of microglia in viral encephalitis,propose questions to be answered in the future and suggest possible therapeutic targets.
基金the Health Research Board(HRA-POR-2015-1243)the Science Foundation Ireland(17/CDA/4708 and co-funded under the European Regional Development Fund and by FutureNeuro industry partners 16/RC/3948)+3 种基金H2020 Marie Sklodowksa-Curie Actions Individual Fellowships(753527,796600 and 844956)the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement(766124)the Deutsche Forschungsgemeinschaft(German Research FoundationProject-ID 335447717-SFB 1328)。
文摘Mounting evidence suggests that the ATP-gated P2X7 receptor contributes to increased hyperexcitability in the brain.While increased expression of P2X7 in the hippocampus and cortex following status epilepticus and during epilepsy has been repeatedly demonstrated,the cell type-specific expression of P2X7 and its expression in extra-hippocampal brain structures remains incompletely explored.In this study,P2X7 expression was visualized by using a transgenic mouse model overexpressing P2X7 fused to the fluorescent protein EGFP.The results showed increased P2X7-EGFP expression after status epilepticus induced by intra-amygdala kainic acid and during epilepsy in different brain regions including the hippocampus,cortex,striatum,thalamus and cerebellum,and this was most evident in microglia and oligodendrocytes.Colocalization of P2X7-EGFP with cell type-specific markers was not detected in neurons or astrocytes.These data suggest that P2X7 activation is a common pathological hallmark across different brain structures,possibly contributing to brain inflammation and neurodegeneration following acute seizures and during epilepsy.
基金This review was supported by the Centre National de la Recherche Scientifique,University of Bordeaux,and grants from Association pour la Recherche sur la Sclerose Laterale Amyotrophique,Initiative d'Excellencc of Bordeaux,and Laboratoire d'Excellence BRAIN ANR-10-LABX-43.
文摘The P2X4 receptor(P2X4)is an ATP-gated cation channel that is highly permeable to Ca2+and widely expressed in neuronal and glial cell types throughout the central nervous system(CNS).A growing body of evidence indicates that P2X4 plays key roles in numerous central disorders.P2X4 trafficking is highly regulated and consequently in normal situations,P2X4 is present on the plasma membrane at low density and found mostly within intracellular endosomal/lysosomal compartments.An increase in the de novo expression and/or surface density of P2X4 has been observed in microglia and/or neurons during pathological states.This review aims to summarize knowledge on P2X4 functions in CNS disorders and provide some insights into the relative contributions of neuronal and glial P2X4 in pathological contexts.However,determination of the cell-specific functions of P2X4 along with its intracellular and cell surface roles remain to be elucidated before its potential as a therapeutic target in multiple disorders can be defined.
