神经生物学课件：缺血性脑损伤及脑保护

缺血性脑损伤及脑保护

IschemicBrainInjuryandProtection1,

What:

ischemicbraininjury2,

Why:mechanismsunderlying3,

Self-protection:repair/protectitselfafterstroke4,

Therapies:

translationalstrategiesOUTLINE1,Whatisischemicbraininjury?Adecreaseinthebloodsupplytoabodilyorgan,tissue,orpartcausedbyconstrictionorobstructionofthebloodvessels.ISCHEMIA

:

(NewLatinischaemia,fromGreekiskhaimos,astoppingoftheblood:iskhein,tokeepback;seesegh-inIndo-Europeanroots+haima,blood)/ischemiaMayalsobespelledas:ischaemiaorischæmia

RelatedTermsIschemia

缺血

shortageofthebloodsupply(oxygen,glucose,etc)Hypoxia

缺氧

shortageofoxygenAnoxia

缺氧

anextremeformofhypoxia,absenceofoxygenBrainischemia

脑缺血

insufficientbloodflowtothebrain(eg:ischemicstroke)Ischemiccascade

缺血级联反应

aseriesofbiochemicalreactionsthattakeplaceaftersecondstominutesofischemia.Stroketypesandincidence中风中绝大多数是缺血性中风脑血栓形成脑栓塞Blockageofabloodvessel(inthebrainorneck)CerebralischemiaIschemicBrainInjuryFewseconds:littleornodamage10seconds:nooxygensupply30seconds:changesinbrainmetabolism1minute:noneuronalfunctionalactivities6-8minutes

→neuronaldeath,InfarctionNeurologicaldysfunctionoccurswithinsecondstominutesofvesselocclusionIschemicinjuryandcelldeathcontinuesinstagesforminutes,hours,andevendaysofvesselocclusion血栓使大脑中动脉栓塞，供血区血供不足大脑中动脉缺血脑水肿RedNeuronsMacrophagesOedemaCystformation神经细胞受损缺血1h再灌24h，同侧和对侧皮层、纹状 体神经元变化（CV染色）cortexstriatumcontralateralipsilateralSeverelydamagedtissueLowperfusiontissueAfterhourstodays,ischemiccoreterritoryexpands.Ischemiccoreappearswithinminutestohours.脑缺血造成脑梗死缺血核心区ischemiccore缺血半影区penumbraIschemiccore:

irreversiblydamagedtissuesdistaltoanoccludedbloodvessels

<20%ofbaselinebloodflowlevelsdepletedATPstoresirreversiblefailureofenergymetabolismSalvageabletissueisthetargetfortherapy.Ischemicpenumbra:

significantlydepressedtissueperfusionbarelysufficienttosupportbasalATPlevelsaswellasnormalionicgradientsinthepresenceofelectricalsilenceandsuppressedproteinsynthesis

“atrisk”region:functionallyimpaired,potentiallysalvageableDamageMechanismsProtectiveMechanismsCellFateischemiaINischemicpenumbra：1，启动细胞死亡机制2，激活脑内自身保护机制Live?Dead?2,Whydoesischemiacause

braininjury?

Experimentalmodels

ProminentmechanismsunderlyingneuronalinjuryRat,mice,andgerbilarethecommonlyusedmodelanimals.Monkey,cat,andrabbitarealsousedtoestablishstrokemodels.外周血液经两对动脉进入脑内：颈动脉和椎动脉阻断血流（颅内、颅外）：脑缺血

Middlecerebralarteryocclusion(MCAO)

Photothrombosis

光化学诱导

Spontaneousbraininfarction

Four-vesselocclusion

四血管结扎

Commoncarotidarteryocclusioningerbils

Two-vesselocclusionplushypotention

两血管结扎并低血压

Cardiacarrestcerebralischemia(CACI)心脏骤停

Hypoxicischemia

低氧缺血

Intracranialhypertensionandcommoncarotidarteryocclusion

Focalbrainischemia(transient/permanent)

GlobalbrainischemiaLonga,E.Z.,P.R.Weinstein,S.Carlson,R.Cummins(1989)."Reversiblemiddlecerebralarteryocclusionwithoutcraniectomyinrats".Stroke20(1):84–91.PMID2643202IntraluminalsutureMCAO大脑中动脉栓塞MCAO-inducedstrokemodelinrhesusmonkey大鼠行为学视频MCAOinducesbrainedema(bottomleft)andinfarction(right).TopleftshowsMCAO-affectedregioninhumanbrain.rosebengal玫瑰红B四碘四氯荧光素二钠PhotothrombosisstrokemodelWatsonBD,DietrichWD,BustoR,WachtelMS,GinsbergMD.(1985).Inductionofreproduciblebraininfarctionbyphotochemicallyinitiatedthrombosis.AnnNeurol.17(5):497-504Photosensitivedye:rosebengalSpecificlighting:卤素灯或氙灯Photochemicalreactionproducts:

reactiveoxygenspeciesDamage:VascularendothelialcellinjuryThrombosisformationLeft:Cortical“spot”lesion,carbonblackviewat4hRight:Occludedarterioleinpia,perfusedat2min;SEMx4160Left:562nmdyelaserbeam

positionedondMCARight:Rosebengaldye-photosensitized

dMCAthrombusImagesfrom/x301.xml光化学诱导模型可用于研究溶栓药物的作用Imagesfrom/lawrence.lab/files/page_4_01.html全脑缺血模型中，海马神经元最易受影响HypoxiachamberImagesfromJournalofCerebralBloodFlow&Metabolism(2004)24,259–270ligationoftheright(orleft)commoncarotidarteryof7-day-oldpups,followedby90minuteofhypoxia(8%02and92%N2)at37℃.

Hypoxia-ischemiamodel

CellcultureOrganotypicbrainslicecultureIn

VitrocultureOxygen-glucosedeprivation(OGD)

hypoxiachemicalhypoxia

NeuronalcultureOrganotypicslice——maintainneuronalorganizationforextendedperiodsoftime

更接近在体状态数周至数月(A)Brightfield,(B)and(C)PI-fluorescenceimagesofratorganotypichippocampalslicecultures(labeledareCA1,CA3subfieldsandDG:dentategyrus).(B)Neuronalcelldeath24hafter‘test’ischemia(40minofOGD).(C)Reducedcelldeathinapreconditionedslice(15minofOGD48hpriortotestischemia).Barindicates0.2mm.Neuroscienceletters,384(2005):87-92ischemiatreatment2,Whydoesischemiacause

braininjury?

Experimentalmodels

Prominentmechanismsunderlyingneuronalinjury缺血细胞内信号转导细胞间通讯缺血中心区细胞死亡缺血损伤向四周扩布？AB1B2CD神经元的突触结构CBFreduction↓Energyfailure↓Anoxicdepolarization,Excitotoxicity,Oxidativestress,Necrosis↓Peri-infarctdepolarization,Calciumoverload,Mitochondrialdamage↓Inflammation,celldeathNeuronalischemicinjurycascade

Glutamateexcitotoxicity谷氨酸兴奋毒神经元受损的早期环节(1)LucasD.R.OlneyJ.SchwarczR....Pre-1984Post-19841984LUCASDR,NEWHOUSEJP.(1957).ThetoxiceffectofsodiumL-glutamateontheinnerlayersoftheretina.AMAArchOphthalmol.58(2):193-201OlneyJW.(1969).Brainlesions,obesity,andotherdisturbancesinmicetreatedwithmonosodiumglutamate.Science.164(880):719-21

过量谷氨酸可以破坏新生小鼠视网膜神经元(LucasDR,1957)全身应用谷氨酸可导致脑内神经元的退化性病变(OlneyJW,1969)谷氨酸引起神经元死亡的作用通过兴奋突触后膜上离子通道型谷氨酸受体1984

缺血时细胞外谷氨酸含量上升(Benvenisteetal.).

谷氨酸受体拮抗剂保护培养的神经元免受谷氨酸或者门冬氨酸兴奋毒(Rothman).

NMDA受体拮抗剂降低缺血诱导的神经元损伤

(Simonetal.).

Post-19841984Pre-1984脑缺血后细胞间隙谷氨酸含量显著升高corepenumbraGLUCytosol10mMVesicles100mMExtracellular1MTGLUGLUSynapticspace1mM？谷氨酸浓度梯度谷氨酸转运体的作用胞外<<胞浆<<囊泡内递质释放时excitotoxicityEndogenousPresynapticPostsynapticGliaGlu-RGluvGlucGlucs.c.e.s.e.s.Glia1984Pre-1984Post-1984YProcessesinvolvedintheinactivationofsynaptictransmissionYYYYYYUU=uptakeDD=diffusionYZMM=metaboliteYYYYRR=receptordesensitisationFaliureofglutamatereuptakeOutInATPNa+K+

K+Na+

K+CGlu2Na+DeficientglutamateuptakeDeficientenergysupply(ischaemia,mitochondrialdamage)LossoftheNa/K-transmembranegradient(drivingforceofthecarrier)谷氨酸转运体AMPA-RPostsynapticabnormalitiesleadingtoexcessiveexcitationIonotropicreceptors(GluR)Metabotropicreceptors(mGluR)Ca2+NMDA-RNa+Na+Kainate-RG

Increasedaffinityoftheglutamatebindingsite;

Increaseddensityofglutamatereceptor;

Deficientcationselectivityoftheionophore;

Abnormal(positive)modulationofGluRfunction.谷氨酸受体Presynaptic

release:↑Reuptake:↓synapticglutamate:↑Postsynaptic

receptor:↑Excitation:↑Na+内流Na+内流Ca2+内流内钙释放Ca2+内流NMDA受体AMPA受体KA受体mGlu受体谷氨酸水肿内钙超载nNOSPLA2…ROSCelldeath？ClinicaltrialsfailureCategoryNameClinicalefficacyGlutamatereceptorblockadeAptiganel/dextrophan/EliprodilNoneGlutamatehypothesismay:Oversimplifiedthecomplexityofthecelldeathprocesses:Underestimatedthediversityofexpressingcelltypes:

beyondneurons

Shouldconsidertheheterogeneityofglutamateresponses:

selectivelytargetFunctionaldiversityofNMDARsisrootedintheirlocationandsubunitdiversity.Example1:→Selectivedrugtargetisimportant.Location:synapticvs.extrasynapticSubunitcomposition:GluN1,GluN2(2A-2D),GluN3(3A-3B)

GluN1/GluN2A:dominatinginadulthood;

withinsynapse

greaterassociationwithcellsurvival

GluN1/GluN2B:dominatingearlyindevelopment;

outsidesynapse

linkedtocelldeathsignalingGluN3:inhibitorysubunit,peakattheendofthefirstpostnatalweeksuppressesNMDARactivityLocationAssociateswithDifferentIntracellularSignalsParsonsMP,etal.Neuron,2014GluN2BLaiTW,etal.ProgNeurobiol.,2014SubunitscompositionAssociateswithDifferentIntracellularSignalsGluN2AC-terminaldomainSynapticactivityviaGluN2A:CREB/BDNFpositivefeedbackloopExtrasynapticactivityviaGluN2B:CREBshut-offpathwayPhospholipidpathwaysleadingtoneuronaldeathandsurvival:AktandPTENPI3KPIP3PIP2PTENAktAmJPhysiolCellPhysiol308:C570-C577,2015ImmunocytochemistryshowedcolocalizedlabelingofGluN1Igreen)andGluN3A(red)inprimarycorticalneurons.ExpressionpatternsofGluN3Ainthemousebrain.NeuroprotectiveeffectofGluN3AagainstexcitotoxicinsultsincorticalNeurons.NeuroprotectiveroleofGluN3AinischemicstrokeoftheadultmouseGLIAL:GLAST/EAAT1RetinalMullercells77MCerebellarBergmanngliaGLT-1/EAAT2Astrocytesthroughoutbrain2MNEURONAL:EAAC1/EAAT3Neuronalsomataanddendrites15MEAAT4CerebellarPurkinjecells3.3MEAAT5Retinalphotoreceptorsand64M

bipolarcellsThenameoftheglutamatetransporterfamilymembers.Theexcitatoryaminoacidtransporter(EAAT)namesareforthehumantransporters;othernamesweregivenwhenthetransporterswerefirstclonedinnonhumanspecies.Example2:NonneuronalcelltypesCerebralcortexStriatumHippocampusThalamusInsituhybridizationforEAAT1mRNAandimmunohistochemistryforEAAT1proteinafterH-IDoublestainingwithconfocallaserscanningmicroscopicanalysisinneonatalratbrainsImmunohistochemicalstainingintheneonatalratbrainat48hfollowingH-IH-I+sense

H-I+antisense0510152025cerebralcortexstriatumhippocampusthalamusEAAT1-positivecells/mm2vehicleantisensesensemissense****Sham-operationH-I+senseH-I+antisenseCresylvioletstainingintheneonatalratbrainat48hfollowingH-I:*Example3:PDZproteinsatamammalianexcitatorysynapseintracellularcalciumoverload胞内钙超载神经元受损的早期环节(2)extracellularcalcium:[Ca2+]o=1~10mMintracellularcalcium:

cytosolic：

0.1%ofintracellularcalcium[Ca2+]i=100nM=0.1M

calciumstores：99.9%calciumbindingprotein:calmodulin,calbindin,parvalbumin,calretinin

endoplasmicreticulummitochondriaCalciumhomeostasisinneuronsVOCs:voltage-operatedchannelsROCs:receptor-operatedchannelsSMOCs:second-messengeroperatedchannelsSOCs:store-operatedchannelsRyRs:ryanodinereceptors,bycalciumitself(CICR)orbyvoltage(DICR)SR:sarcoplasmicreticulumER:endoplasmicreticulumS:ahypotheticalcalciumsensorAllcurrentlyknowncalciumchannelproteinsCalciuminflux:glutamate-dependentglutamate-independentCalciumreleasefromstores:CalciumeffluxERmitochondria3Na+2Ca2+Na+/Ca2+exchangerCa2+ATP-dependentCa2+pumpsIP3receptoruniporterCa2+pumpsNMDARmGluRsvoltage-dependentCa2+channels(VDCC)IP3GqPLCAMPARNa+/Ca2+exchangerNicholsonC,BruggencateGT,SteinbergR,StöckleH.(1977).Calciummodulationinbrainextracellularmicroenvironmentdemonstratedwithion-selectivemicropipette.ProcNatlAcadSciUSA.74(3):1287-90.

anoxiatriggersrapidtranslocationofcalciumfromextratointracellularspacesinneuraltissue.Thisworkpromptedspeculationaboutwhycertainneuronsareselectivelymoresensitivetoischemia,namelybecauseofahigherdensityofcalciumchannelsintheirplasmamembranes.1977;Nicholsonetal:缺血缺氧导致胞内钙超载Glutamate-inducedCa2+transientsincorticalneuronsobservedbyconfocallasermicroscopy.Thetimecourseofthenormalizedfluorescenceintensity.Zerotimeindicatesbeginningofpostexposurephase.Eachcurverepresentsapointrecordingfromadifferentcellinthedish.Fluo-3flunorescenceintensitywereobtainedbeforeandduringstimulationwith1mMglutamateatintervalsof4sec.IntracellularcalciumoverloadingnormalaspartatewashAsp+tauERmitochondria3Na+2Ca2+Na+-Ca2+exchangerCa2+ATP-dependentCa2+pumpsIP3receptoruniporterCa2+pumpsNMDARmGluRsvoltage-dependentCa2+channels(VDCC)IP3GqPLCAMPARIschemia!!细胞内游离钙离子激活一系列钙离子依赖性酶反应Ca2+→calcineurin-mediateddephosphorylationandactivationofDAPK1atser-308Excitotoxicityrecruitsdeath-associatedproteinkinase1(DAPK1)tothecytoplasmictailofGluN2B.Ca2+→calpainactivation→mGluR1truncation→neuronaldeath→p35truncation→neuronaldeath→STEP61truncation→neuronaldeathCouplingbetweenNMDAReceptorandAcid-SensingIonChannelContributestoIschemicNeuronalDeathASIC1a:

Acid-sensingionchannels(ASICs)highlypermeabletoCalciumCalciuminfluxGlobalIschemiaRapidlyElevatedSerinePhosphorylationofASIC1aSubunitGlobalIschemiaIncreasedtheAssociationofCaMKIIawithASIC1aNMDARActivationIsRequiredforIschemia-InducedEnhancementofASIC1aPhosphorylationNR2B-specificblockersNMDARAMPARActivationofNR2B-NMDARsEnhancedASICCurrentsNR2BAntagonistorCaMKIIInhibitorPreventedOGD-InducedEnhancementofASICCurrentsinHippocampalNeuronsNeuroprotectionbyASIC1aGeneDeficiencyandASIC1aMutantsinCulturedHippocampalNeuronsorCOS7Cells

NMDAR-CaMKIIcascadeisfunctionallycoupledtoASICsandcontributestoacidotoxicityduringischemia.SpecificblockadeofNMDAR/CaMKII-ASICcouplingmayreduceneuronaldeathafterischemiaandotherpathologicalconditionsinvolvingexcessiveglutamatereleaseandacidosis.Thus:Oxidative/nitrosativestress氧化/硝化应激神经元受损的分子基础AngioplastyKeshandisease(seleniumdeficiency)TraumaStrokeNeurotoxinsParkinson’sDiseaseAlzheimer’sDiseaseRadiationAgingCancerInflammatory-immuneinjuryIschemia-reperfusionDiabetesKidneySkinHeartJointsLungBrainMulti-organVesselsGIEyeRenalgraftGlomerulonephritisBurnDermatitisPsoriasisIschemicbowelEndotoxinliverInjuryAsthmaHyperoxiaVasospasmAtherosclerosisRheumatoidAthritisDegenerativeretinaldamageCataractogenesisOxidativeStressOxidativestress-relatedclinicalconditionsWhatisoxidativestress?Oxidativestressistheimbalancebetweencellularproductionofreactiveoxygenspecies(ROS)andtheabilityofcellstodefendagainstthem.氧化应激：体内氧化与抗氧化作用失衡，氧化作用增加，产生大量氧化中间产物。硝化应激：由NO或NO衍生的活性氮族与活性氧族共同联合发生的反应，可使蛋白质的酪氨酸硝化成硝基酪氨酸，或者使半胱氨酸巯基发生S-亚硝基化。Reactiveoxygenspecies(ROS)

活性氧自由基

Freeradicals:自由基

AnychemicalspecieswithoneormoreunpairedelectronsReactivenitrogenspecies(RNS)

活性氮自由基

themostcommoncellularfreeradicals-superoxideradicalO2-（超氧阴离子）-hydroxylradical•OH（羟自由基）-nitricoxideradicalNO•Others:(notfreeradicalsbutcanleadtothegenerationoffreeradicals)-Hydrogenperoxide

H2O2-PeroxynitriteONOO-

过氧亚硝酸阴离子ROS/RNSarephysiologicallygeneratedandmaintainedatrelativelylowlevels.Enzymes,antioxidantsROS的清除DifferentsourcesofROSgenerationleadingtovariouslipidperoxidesformation.脑缺血脑缺血脑缺血产生大量自由基，抗自由基系统活性下降Duringischemia,ROSweregeneratedprincipallybymitochondria.Recentlyshown:

NADPHoxidase(NOX)istheprimarysourceofsuperoxideinducedbyNMDAreceptoractivation.PKCnNOSXDH:黄嘌呤脱氢酶XO：黄嘌呤氧化酶

involvedinpurinedegradationNOX：NADPH氧化酶

amembrane-boundenzymecomplexbefoundmainlyintheplasmamembraneNOS：NO合酶线粒体功能障碍，SOD等活性下降黄嘌呤氧化酶过度活化次黄嘌呤→黄嘌呤+尿酸+O2-花生四烯酸代谢增加

Ca2+→PLA2/PLC→AA↑→O2-NOS→

NO，进一步介导自由基的生成。。。。。。脑缺血后多条途径产生自由基：

TheNobelPrizeinPhysiologyorMedicine1998RobertF.Furchgott

SUNYHealthScienceCenter

Brooklyn,NY,USA

b.1916LouisJ.Ignarro

UniversityofCaliforniaSchoolofMedicine

LosAngeles,CA,USAb.1941FeridMurad

UniversityofTexasMedicalSchoolatHouston

Houston,TX,USAb.1936Http:///research/medicine/biochemistry/bioc800/sig02-06.htmNOScoupling→NONOSuncoupling→O2-insteadofNOTypesofNOSnNOSneuronalNOSCentralandperipheralneuronalcellsCa2+dependent,usedforneuronalcommunicationiNOSinducibleNOSMostnucleatedcells,particularlymacrophagesIndependentofintracellularCa2+

InducibleinpresenceofinflammatorycytokineseNOSendothelialNOSVascularendothelialcellsCa2+dependentVascularregulation

H+

NO+O2

ONOO-

ONOOH

NO2•+OH•

协同花生四烯酸损Pr、核酸、脂质膜损Syn.前Glu转运体

Glureuptake

Glu浓度脑缺血时大量超氧化物与NO反应CategoryNameClinicalefficacyFreeradicalscavengers/antioxidantsPergorgotein/tirilazad/ebselenNoneorminimalClinicaltrialsfailureTosuppressdeleteriousradicalswithoutinterferingwithendogenoussignalingwillbeimportant.FromCalabresietal.,2003Celldeath细胞死亡神经元受损的最终归宿坏死凋亡焦亡自噬坏死性凋亡JNeurochem.(2015)10.1111/jnc.13362ApoptosisandnecrosisCellshrinkage,membraneblebbing,chromatincondensation,apoptoticbodyformationMethodsofdetectingapoptosisMorphologyElectronmicroscopyLightmicroscopyChromatincondensationStainingnucleiwithfluorescentdyessuchasDAPI,Hoechst,acridineorangeDNAfragmentationTUNEL(TdT-mediateddUTP-biotinnickendlabeling)InternucleosomalDNAladderFACSanalysisofDNAcontent(<2NDNA)Viabilitydyeexclusion,trypanblue,propidiumiodideAnnexinVbindingtophosphatidylserinewhichisflippedtooutsideofplasmamembrane earlyinapoptosisMTT-assaysabilityofactivemitochondriatocleavecolorimetricsubstrateCaspaseActivation--caspasecleavageeventsCytochromecreleasefrommitochondria

UVApoptosisinResponsetoUV-irradiationAnnexin-VstainingHoechststainingDNAFragmentationApoptosissignalsFasligandFasCaspase8BidCytochromecCaspase3Caspase7FADDIntrinsicpathwayExtrinsicpathwayAPOPTOSISBclBax细胞内源性通路细胞外通路BaxTakahashiA,MasudaA,SunM,CentonzeVE,HermanB.(2004).Oxidativestress-inducedapoptosisisassociatedwithalterationsinmitochondrialcaspaseactivityandBcl-2-dependentalterationsinmitochondrialpH(pHm).BrainResBull.62(6):497-504.LinksAutophagy:自噬Energydependentprocess“自食”

LC3dependentOrLC3independentTreatmentofstrokeCategoryNameClinicalefficacyAnticoagulation/thrombolysisAspirin/heparin/tPA/urokinaseModestGlutamatereceptorblockadeAptiganel/dextrophan/EliprodilNoneVoltage-gatedCa2+channelblockersNimodipine/lifarizine/flunarizineNoneNa+channelblockersLubeluzole/riluzolUnclearornoneVoltage-dependentK+-channelagonistBMS-204352BeingtestedEnhancementofinhibitoryneurotransmissionClormethiazoleBeingtestedFreeradicalscavengers/antioxidantsPergorgotein/tirilazad/ebselenNoneorminimalNeuralrepairCiticholine/troferminUnclearorminimalTreatmentofstrokeCategoryNameClinicalefficacyAnticoagulation/thrombolysisAspirin/heparin/tPA/urokinaseModestGlutamatereceptorblockadeAptiganel/dextrophan/EliprodilNoneVoltage-gatedCa2+channelblockersNimodipine/lifarizine/flunarizineNoneNa+channelblockersLubeluzole/riluzolUnclearornoneVoltage-dependentK+-channelagonistBMS-204352BeingtestedEnhancementofinhibitoryneurotransmissionClormethiazoleBeingtestedFreeradicalscavengers/antioxidantsPergorgotein/tirilazad/ebselenNoneorminimalNeuralrepairCiticholine/troferminUnclearorminimal动物实验有效，但临床疗效不佳！Everythingworksinanimalsbutnothingworksinpeople.O’collinsetal,2006DamageMechanismsProtectiveMechanismsCellFateischemia缺血半影区的神经元病理变化：1，启动细胞死亡机制2，激活脑内自身保护机制Live?Dead?3,Howdoesthebrainrepair/protectitselfafterstroke?

Neurogenesisaftercerebralischemia!

SVZ:subventricularzoneSGZ:subgranularzoneNeurogenesisinthestriatuma,NeuralstemcellsorprogenitorcellsresideintheSVZ.b,Focalischemicinsultsgiverisetoincreasedproliferationofprogenitors.c,Neuroblastsformedafterandtosomeextentalsobeforethestrokethenmigratetothedamagedpartofthestriatum.d,Theyexpressmarkersspecificforstriatalprojectionneurons.CurrentopinioninNeurobiology,2003,13:127-132SelfrepairmechanismNaturemedicine,2002,8(9):963-970Dcx(green)andBrdu(red)immucoreactivityintheipsilateralstriatuminfusedwithsaline(upperlayer)andAra-c(lowlayer).Naturemedicine,2002,8(9):963-970Strokegeneratedcellsexpressmarkersofdevelopingstriatalneurons2weeksafterstrokeandmarkersofmaturestriatalneurons5weeksafterstroke..DARPP32BrdUDARPP32-BrdUScience,(287),2000,1433-1438NeurogenesisinthehippocampusNestininthehippocampusafterischemia.Nonischemichippocampus(A,D).Sevendaysafterischemia,(B,E)

JournalofNeuroscienceResearch69:750–756(2002)

Vascularremodelingaftercerebralischemia!StrokeinducestransientdecreaseofvesseldensityinSVZandlong-termincreaseofSVZvolumeandvesseldensityinadjacentstriatum.Strokeinduceslow-gradeangiogenesisinSVZandadjacentstriatum.Neuroblastsmigratelong-termafterstrokeclosetobloodvesselsinstriatalsubzonewithincreasedvascularization.JNeurochem.(2015)10.1111/jnc.13362Neurovascularunitdynamicsinthecerebraltissueatthesubacuteperiodpost-strokeTightjunctionsbreak;Basallaminadegrade;Astrocytesreactive;Parenchymalswells;TrophicfactorsincreaseProgressofcellularalterationinducedbystroke<8h8-48h>48hJNeurochem.(2015)10.1111/jnc.133624,NewTranslationalstrategies神经元并非孤立存在神经元星形胶质细胞神经元、星形胶质细胞小胶质细胞神经元神经元

星形胶质细胞RemodelingtheNeurovascularUnitinsteadofprotectneurononlyWhitematterstrokeinjury:disruptedconnectivity;injuredaxonsandglialcells

Differsfromthoseingreymatter!Brainresearch,2015(1623):123-134Ischemiccore:axon-gliacompletelossPeri-infarctarea:demyelinationRegenerativeresponseInhibitorysignalsTrophicfactorsMolecularpathwayinvovledinWhitematterstrokeinjuryandrepair:

Extracellularmatrixrelatedproteins:CSPGs,hyaluronan,MMPsActivity