07信号转导与心血管疾病.ppt

细胞信号转导与心血管疾病,病理生理学系,细胞信号转导系统概述,TLRs介导的细胞信号转导,TLRs信号通路与心血管疾病,细胞信号转导系统(signaltransductionsystem)由受体或其他可接受信号的分子、细胞内的信号转导通路及其作用的终端所组成。意义对认识细胞在生命活动各方面的表现和调控方式，理解生命活动的本质，在分子水平认识各种疾病的发病机制等都有重大意义。,第一节细胞信号转导系统概述,细胞通讯,细胞通讯（cellcommunication）：指一个细胞发出的信息通过介质传递到另一个细胞产生相应反应的过程。,细胞通讯主要有三种方式：细胞间隙连接(gapjunction)：连接蛋白，直接通讯，可共享小分子物质（1500D）膜表面分子接触通讯(Contact-dependentsignaling)：蛋白、糖蛋白、糖脂，直接通讯化学信号通讯(chemicalsignaling)：以化学信号为介质，间接通讯,细胞间隙连接,膜表面分子接触通讯,化学通讯,信号转导（signaltransduction）：指外界信号（如光、电、化学分子）与细胞细胞表面受体作用，通过影响细胞内信使的水平变化，进而引起细胞应答反应的一系列过程。,信号转导,细胞信号传导的基本过程和机制,受体：识别外源信息分子(配体ligand);信号转换。,信号的接受和转导,细胞信号分子：生物细胞所接受的信号既可以是物理信号（光、热、电流、机械刺激），也可以是化学信号，但是在有机体间和细胞间的通讯中最广泛的信号是化学信号。,信号分子,化学信号根据其溶解性可分为脂溶性和水溶性两类。脂溶性信号分子，主要是甾体类激素和甲状腺素，它们分子小、疏水性强，可直接进入细胞，与细胞质或细胞核中受体结合形成激素-受体复合物，调控基因表达；水溶性信号分子：大部分激素、递质和细胞因子都是亲水性的，他们不能穿过细胞膜，只能通过与靶细胞表面受体结合，经信号转导机制，在胞内产生第二信使或激活蛋白激酶的活性，引起细胞效应。,信号分子,化学信号的作用方式：内分泌(endocrine)系统的化学信号：激素(hormone)，作用距离最远（m），膜受体或胞内受体旁分泌(paracrine)系统的化学信号：细胞因子，作用于周围细胞（m），膜受体。神经元间的突触信号发放也属于旁分泌，神经递质(neuraltransmitter)，如乙酰胆碱(acetyl-choline)，作用距离最短（nm），膜受体。自分泌(autocrine)：作用于自身，常见于病理条件，如肿瘤。内在分泌(intracrine):某些配体分子如激素等在合成以后并未分泌出细胞，而直接与其胞内的受体结合启动信号转导，主要见于核受体家族。,化学信号的作用方式：,（Transmembranesignaltransductionmediatedbymembranereceptor）,1)离子通道受体（Directligand-gatedion-channeltype）即有信号接收部位，又是离子通道，跨膜转导无需中间步骤，反应快速（ms），如Ach受体通道（N型Ach受体）。Ionotropicreceptor-receptor+ionchannel2)G蛋白偶联型受体（Gproteincoupledreceptor(GPCR)）AC：AMPcAMPasubunit+GTPPLC：PIP2DAG，IP33)具有酶活性的受体（Proteinkinase-linkedtype）既具有受体功能，又具有酶活性，可将胞外信号直接转化为胞内效应。受体酪氨酸蛋白激酶(receptortyrosinekinase，RTK)丝苏氨酸蛋白激酶(proteinserinethreoninekinase，PSTK)型受体,膜受体介导的跨膜信号转导,Gproteincoupledreceptor(GPCR)Ligand:hormone,light,odorousmolecules,neurotransmitter,neuropeptide,chemotacticfactor,etcbagGDPGTPAC-cAMP-PKA(cAMPdependentproteinkinase)aPLC-b-DAG-PKC(Ca2+,PLdependentproteinkinase)PLC-g-IP3-Ca2+(Ca2+-CaMdependantproteinkinase)GTPPI-3K-PIP2,PIP3-PDK-PKBIonchannel,（Signaltransductionmediatedbynuclearreceptor）,Neuclearreceptor(NR):Steroidhormonereceptor(e.g.GR);Thyroxinereceptor(TR);Retinoidacidreceptor(RAR);1,25(OH)2D3receptor(VDR);TF=transcriptionalfactorDNA-bindingareahormone-bindingareaNA/BCEC-HSP(GR)HERGene(TR,RAR,VDR)NA/BCEC+TIFHER=hormoneresponseelementHSP=heatshockproteinTIF=transcriptionalintermediaryfactor(co-activator,co-repressor),核受体介导的信号转导,细胞信号传导的基本过程和机制,（二）信号的抑制和终止,(1)Signalingtermination1)dissociationofreceptorwithligand2)receptorinternalizationanddegradation(down-regulation)3)transferofGPorsmallGPfromactivetoinactivetype4)dephosphorizationbyPPordegradationof2ndmessenger(2)Signalinhibitionandantagonistbetweensignalpathway1)inhibitoryreceptorsandinhibitorytransductioncomponents2)negativefeedbackregulationofsignalpathwayreceptorphosphorylationleadingtoaffinitytoligandreceptordown-regulationinhibitoryelement(CIS)inducedbysignalpathway(JAK-STAT),1、启始配体与受体结合，启动膜内侧级联反应，将信号传给第二信使分子。2、转导（放大和整合）多种信使分子通过不同通路激活一系列蛋白激酶传导信息，实现信号的放大与整合。3、细胞反应（效应）信号分子或转录因子进入细胞核，与基因相互作用，调节蛋白质合成或细胞分泌、运动、形态变化和凋亡。4、中止通过负反馈途径，活化抑制因子或灭活因子，终止信号的启动作用。,受体介导的信号传导的基本过程,Cross-Talk,细胞信号转导大事记,1955年，cAMP第二信使学说，获1971年诺贝尔生理和医学奖1963年，cGMP作为胞内信使的发现1978年，Ca2+第二信使学说1983年，IP3和DG作为胞内信使的发现80年代，G蛋白的研究，获1994年诺贝尔生理和医学奖80-90年代，酪氨酸蛋白激酶与信号转导的研究1997年，Janeway等第一次报道了人的Toll同源物TLR4，到目前为止至少已有11种人TLRs和13个小鼠TLRs被克隆,Dr.Janeway.,JImmunol,1998;539.,第二节TLRs介导的细胞信号转导,Abbreviations:TLRs(Toll-likereceptors)TIR(Toll/IL-1resistance)MyD88(MyeloidDifferentiationprotein-88）MAL(MyD88-adapter-like;alsoknownasTIRAP)TIRAP(TIRdomaincontainingadaptorprotein)IRAK(IL-1receptor-associatedkinase)TRAF6(TNFreceptor-associatedfactor6)TAK-1(TGF-activatedkinase-1)TAB2(TAK1bindingprotein2)TRIF(TIR-domain-containingadapterproteininducinginterferon-)TRAM(TRIF-relatedadaptermolecule)TICAM-1(TIRdomaincontainingadaptormolecular1)Tollip(Toll-interactingprotein)PAMP(pathogenassociatedmolecularpattern)HSP(heatshockprotein)IRF(interferonregulatoryfactor),TLRsstructureincludeaLRRandaTIRdomain,TLRsisatypeItransmembranereceptor.,WhatthehTollwillectodomainlooklike?,LigandspecificitiesofmammalianTLRs,TLR4MyD88-DependentSignaling,MAL,MyD88,Cellmembrane,TLR4,LPS,TLR4MyD88-IndependentSignaling,MyD88DependentandIndependentPathways,NF-B,TNFCOX2IL-18Chemokines,Chemokines:Rantes,IP-10IFN,MyD88hasaDeathdomain(DD),MyD88isanadaptermolecule.ItrecruitsIRAKtheTolllikereceptorcomplexesfollowingstimulation.TheassociationbetweenMyD88andIRAKismediatedthroughaDD-DD(blue)interaction(DDmeandeathdomain).,TLRSignalingPathways,Cellmembrane,TLR3TLR7TLR8TLR9,TLR2/TLR1TLR2/TLR6TLR4,MALMyD88,TRIFTRAM,TRIFMyD88,Endosome,IRF3,IRF7,MALMyD88,TLR4,LPS,TLR4MyD88-DependentSignaling,MAL,MyD88,IRAK4,IRAK2,IRAK1,TRAF6,IKK-,IKK-,IKK-,Cellmembrane,PazS.,NakhaeiP,(2005),TLR4,LPS,TRIF,TRAM,TRAF6,TBK1,IKK,IKK-,IKK-,IKK-,TLR4MyD88-IndependentSignaling,Cellmembrane,Proteasome,PazS.,NakhaeiP,(2005),Lateinduction,CpGDNA,dsRNA,ssRNA,ssRNA,CpGDNA,MyD88,IRAK4,IRAK1,Endosome,TLR7/8,IKK-,IKK-,IKK-,LPS,NF-B,IFN-,TRIF,TLR4,TRAM,TBK1,IFN-,Tyk2,Jak1,STAT2,STAT1,STAT2,STAT1,IRF-9,Cellmembrane,TLR9,Proteasome,TRAF6,InflammatoryCytokines,IFNRegulation,PazS.,NakhaeiP,(2005),TLR4,TNFCOX2IL-18,MAL,MyD88,IRAK4,IRAK1,UBC13,Cellmembrane,ST2,SIGIRR,Cytoplasmicmolecules:IRAK-M:induciblebyTLRstimulation;anti-inflammatorySOCS1(Supressorofcytokinesignaling1):inhibitsJAK-STATsignalingA20:CreatesnegativefeedbackloopinhibitingNFkappaBandTNF-mediatedprogrammedcelldeath.Tollip:inhibitsTLR2and4signalingMyD88forms:alternativesplicingcreatesshortmoleculesthatinterferewithsignaling.Membraneboundmolecules:SIGIRR(singleimmunoglobulinIL-1R-relatedmolecule)ST2,NegativeRegulationofTLRSignaling,A20,Tollip,第三节TLRs信号通路与心血管疾病,InflammationCauseHeartAttack,Atherosclerosisandinflammation,HanssonGKNEnglJMed2005;352:1685-95,Recently,apossibleroleforTLR4signalinginarterialremodelinghasbeenrevealedinmousemodels.,TLRshaverecentlybeenassociatedwithatherosclerosis.,Inmousemodelsofhyperlipidemia,apotentialroleforthetoll-likereceptorpathwayhasbeensuggestedinhypercholesterolemia-inducedatherosclerosis.,Inaddition,oxidizedlipoproteinsinteractwithtoll-likereceptors.Lipid-richatheroscleroticplaquesexpressTLR4,andthatTLR4expressioninmacrophagesisup-regulatedbyoxidizedbutnotnativelow-densitylipoprotein(LDL).,HumanepidemiologicstudieshavelinkedTLR4polymorphismwithatherosclerosis.,RoleofTLRsignalinginatherosclerosis,MyD88andTLR4deficiencyreducestheextentofaorticatherosclerosis,AortasstainedforlipiddepositionwithOilredO,Lipidcontent,macrophageinfiltration,andCOX-2expressioninaorticsinusplaquesisreducedinApoe-/-MyD88-/-mice.,AtheroscleroticplaquesstainedforlipiddepositionwithOilredO,Macrophageinfiltrationinaorticsinusplaques,ThesectionswereincubatedwithMOMA-2,amacrophage-specificantibody,orcontrolIgGantibody.,COX-2expressioninaorticsinusplaques,QuantitativeanalysisofCOX-2immunofluorescentstaininginscleroticplaques,SerumconcentrationofIL-12p40andMCP-1arereducedinApoe-/-MyD88-/-mice.,IL-12p40andMCP-1concentrationsintheseraofmiceweremeasuredbyELISAs.,Increasedinflammatorycytokine(TNF,IL-1andIL-6)expressionhavebeenfoundinCHFandischemichearts.,Reperfusioninjuryisrelatedcloselytoinflammatoryreactionssuchasactivationofinflammatorycellsandexpressionofcytotoxiccytokines.,MoleculesreleasedfromdamagedbloodvesselsorextracellularmatrixhavebeenidentifiedasendogenousactivatorsofTLRs.,RoleofTLRMediatedSignalinginCardiacIschemiaInjury,RoleofTLRMediatedSignalinginCardiacIschemiaInjury,RoleofTLRMediatedSignalinginCardiacIschemiaInjury,RoleofTLRMediatedSignalinginCardiacIschemiaInjury,ReducedMyocardialIschemia-ReperfusionInjuryinToll-LikeReceptor4DeficientMice,RoleofTLRMediatedSignalinginCardiacIschemiaInjury,TLR4deficientmicehassignificantlysmallermyocardialinfarctionscomparedwithwildmicegivensimilarareasatriskafterMIR.,FewerneutrophilsinfiltratedthemyocardiumofTLR4-deficientmiceafterMIR.Fewerlipidperoxidesandlesscomplementdeposition.Serumlevelsofinterleukin-12,interferon-,andendotoxinwerenotincreasedafterMIR.,Inadditiontoitsroleininnateimmuneresponses,TLR4servesaproinflammatoryroleinMIRinjury.,A20IsDynamicallyRegulatedintheHeartandInhibitstheHypertrophicResponseStuartA.Cook,etal.Circulation2003;108:664-668,Editorial:Circulation2003;108:638-640IsNFBanAttractiveTherapeuticTargetforTreatingCardiacHypertrophy?NicoleH.Purcell,PhD;JefferyD.Molkentin,PhD,ToinvestigatetheimportanceofNF-Bsignalingintheheartasapotentialmediatorofhypertrophyand/orapoptosisthroughamanipulationoftheNF-BinhibitoryproteinA20,Infectionofcardiomy