雌二醇介导激活雄激素产生NO和oxLDL

Estradiol,actingthroughestrogenreceptoralpha,restoresdimethylargininedimethylaminohydrolaseactivityandnitricoxideproductioninoxLDL-treatedhumanarterialendothelialcells

SusanaNovellaa,b, ,AndrésLaguna-Fernándeza,MacarenaLázaro-Francoa,AguaSobrinoa,CarlosBueno-Betía,JuanJ.Tarínc,ElenaMonsalvea,b,JuanSanchísa,d,CarlosHermenegildoa,b

a

ResearchFoundation,HospitalClínicoofValencia–INCLIVA,SpainDepartmentofPhysiology,UniversityofValencia,Spainc

DepartmentofFunctionalBiologyandPhysicalAnthropology,UniversityofValencia,Spaind

CardiologyDepartment,HospitalClínicoofValencia,Spain

b

articleinfoabstract

Asymmetricdimethylarginine(ADMA)isanendogenousinhibitorofnitricoxide(NO)synthase.ADMAaccumulation,mainlyduetoadecreaseddimethylargininedimethylaminohydrolase(DDAH)activity,hasbeenrelatedtothedevelopmentofcardiovasculardiseases.Weinvestigatewhetherestradiolpre-ventsthechangesinducedbyoxidizedlowdensitylipoprotein(oxLDL)ontheDDAH/ADMA/NOpathwayinhumanumbilicalarteryendothelialcells(HUAEC).HUAECwereexposedtoestradiol,nativeLDL(nLDL),oxLDLandtheircombinationsfor24h.Insomeexperiments,cellswerealsoexposedtotheunspeci cestrogenreceptor(ER)antagonistICI182780,thespeci cERaantagonistMPPorspeci cago-nistsforERa,ERbandGPER.ADMAconcentrationwasmeasuredbyHPLCandconcentrationofNObyamperometry.ProteinexpressionandDDAHactivityweremeasuredbyimmunoblottingandanenzy-maticmethod,respectively.oxLDL,butnotnLDL,increasedADMAconcentrationwithaconcomitantdecreaseonDDAHactivity.oxLDLreducedeNOSproteinandNOproduction.EstradiolalonehadnoeffectsonDDAH/ADMA/NOpathway,butincreasedtheattenuatedendothelialNOproductioninducedbyoxLDLbyreductioninADMAandpreventinglossofeNOSproteinlevels.ICI182780andMPPcom-pletelyabolishedtheseeffectsofestradiolonoxLDL-exposedcells.ERaagonist,butnotERbandGPERagonists,mirroredestradioleffectsonNOproduction.Inconclusion,estradiolrestores(1)DDAHactivity,andthereforeADMAlevels,and(2)NOproductionimpairedbyoxLDLinHUAECactingthroughERa.

Ó2012ElsevierIrelandLtd.Allrightsreserved.

Articlehistory:

Received29December2011

Receivedinrevisedform28August2012Accepted29August2012

Availableonline7September2012Keywords:

AsymmetricdimethylarginineEstrogen

Nitricoxidesynthase

1.Introduction

Nitricoxide(NO)playsanessentialroleasmediatorinthecar-diovascularsystemanditsreleaseprotectsthevasculatureagainstvasculardiseases(Vanhoutteetal.,2009).NOismainlyproducedbyendothelialNOsynthase(eNOS)andendothelialdysfunctionischaracterizedbyalossofNObioavailability.ImpairmentofeNOSactivitybyendogenousinhibitorssuchasasymmetricaldimethyl-arginine(ADMA)inendothelialdysfunction-associateddiseaseshasgainedinterest(Leiperetal.,2007).

ADMAexertsitsbiologicaleffectsbycompetitivelyinhibitingNOsynthesisandthusmodulatingthevascularresponse,andelevatedlevelsofADMAhavebeenreportedinmanyconditionsassociatedwithahighcardiovascularrisk.ADMAisametabolicCorrespondingauthorat:ResearchFoundation–INCLIVA,HospitalClínicoUniversitarioofValencia,Av.BlascoIbañez,17,E46010Valencia,Spain.Tel.:+34963864900;fax:+34963864642.

E-mailaddress:susana.novella@uv.es(S.Novella).

0303-7207/$-seefrontmatterÓ2012ElsevierIrelandLtd.Allrightsreserved.http://www.77cn.com.cn/10.1016/j.mce.2012.08.020

by-productofcontinuousproteinturnoverincells,formedduringproteolysisofmethylatedproteins,whichiscatalyzedbyS-adeno-sylmethionineproteinN-methyltransferaseI(PRMT-1).MostofADMAismetabolizedtocitrullineanddimethylaminethroughtheactivityoftwoisoformsofdimethylargininedimethylami-nohydrolase(DDAH)(Popeetal.,2009).DDAH-Iisassociatedwithtissuesthatexpresshighlevelsofneuronalnitricoxidesynthase(nNOS),whereasDDAH-IIisthoughttobeassociatedwithtissuesthatexpresseNOS(LeiperandVallance,1999).However,thebio-chemicalpropertiesandthecontributionofeachenzymetotheregulationofendothelialNOproductionhaveyettobeelucidated(Popeetal.,2009).

Oxidizedlow-densitylipoprotein(oxLDL)actsasariskmarkerforhumancardiovasculardiseaseandasanetiologicalfactorinthepathogenesisofatherosclerosis(Steinberg,2009).Inconditionsofoxidativestress,oxLDLresultsfromoxidationoflow-densitylipoprotein(LDL)atthevascularwallandcancauseendothelialdysfunction(DavignonandGanz,2004).EndothelialcellsexposedtooxLDLshowedmanysignsofdysfunctionorinjury,suchas

12S.Novellaetal./MolecularandCellularEndocrinology365(2013)11–16

impairedNOrelease,disruptedendothelialbarrier,decreasedmigration,inductionofapoptosisandincreasedvesselstiffnesswhichcausemorphologicalchanges(Vanhoutteetal.,2009).

TheincreaseofADMAlevelinpatientsandanimalswithhyper-cholesterolemiaandinendothelialcellstreatedwithoxLDLhasbeenrelatedtoanincreaseofADMAconcentrationasaconse-quenceofadecreasedDDAHactivity,inducedbyoxidativestressand/orin ammatoryfactors(Itoetal.,1999;Bogeretal.,2000).Clinicalandexperimentalstudieshavehighlightedtheroleofestrogensinmanyphysiologicalprocesses,amongthemthecar-diovascularsystem.Indeed,experimentalevidencesuggestthatestrogen,particularlytheendogenous17b-estradiol,exertscardio-vascularprotectionviathepromotionofendothelialvasodilatorsynthesis,includingNOproductionthroughbothincreasedexpres-sionandactivityofeNOS(Mendelsohn,2009)andprostacyclin(Sobrinoetal.,2010)aswellasthroughareductioninendothelialproductionofADMA(Holdenetal.,2003;Monsalveetal.,2007).Theseeffectsaremainlymediatedthroughclassicalestrogenreceptor(ER)aandERb,whicharebothexpressedinendothelialcells(Sobrinoetal.,2010).AthirdtypeofER,G-proteincoupledwhichisprimarilylocalizedtotheendoplasmicreticulum,namedGPER,mediatesseveralrapidandnon-genomicestrogeneffects(ProssnitzandBarton,2011).

TheavailableinformationontheroleofADMAintheregulationofendothelialresponsetoestradiolhasbeenmainlyobtainedinendothelialcellsfromvenousorigin.However,thereisalackofdataabouttheeffectsofestradiolonDDAH/ADMA/NOpathwayonarterialendothelialcells.Despitetheircommondevelopmentalorigins,venousandarte …… 此处隐藏：27261字，全部文档内容请下载后查看。喜欢就下载吧 ……