牡荆素调控iRhom2介导血管内皮细胞焦亡减轻心肌缺血再灌注损伤机制研究

牡荆素调控iRhom2介导血管内皮细胞焦亡减轻心肌缺血再灌注损伤机制研究摘要

目的：本论文旨在探讨牡荆素对iRhom2介导的血管内皮细胞焦亡和心肌缺血再灌注损伤的影响及其机制，为心肌缺血再灌注损伤的临床治疗提供新思路。

方法：采用大鼠心肌缺血再灌注模型，应用Westernblot，real-timePCR，TUNEL染色，细胞定位，荧光染色等技术探究牡荆素在iRhom2介导的血管内皮细胞焦亡中的作用及其下游信号通路。

结果：牡荆素通过下调NF-κB介导的iRhom2的表达从而减轻心肌缺血再灌注损伤，并且调节iRhom2影响MMP-9及Bax，Bcl-2等蛋白的表达水平和细胞凋亡的发生率，从而发挥保护作用。

结论：牡荆素能够调控iRhom2介导血管内皮细胞焦亡及下游信号通路，减轻心肌缺血再灌注损伤。

关键词：牡荆素；iRhom2；心肌缺血再灌注损伤；血管内皮细胞；细胞凋亡

ResearchontheMechanismbyWhichOxymatrineRegulatesiRhom2-MediatedEndothelialCellAutophagytoAlleviateMyocardialIschemia-ReperfusionInjury

Abstract

Objective:ThepurposeofthisstudywastoinvestigatetheeffectofoxymatrineoniRhom2-mediatedendothelialcellautophagyandmyocardialischemia-reperfusioninjury,andtoprovidenewideasfortheclinicaltreatmentofmyocardialischemia-reperfusioninjury.

Methods:Aratmodelofmyocardialischemia-reperfusionwasused,andWesternblot,real-timePCR,TUNELstaining,celllocalization,fluorescencestainingandothertechniqueswereusedtoexploretheroleofoxymatrineiniRhom2-mediatedendothelialcellautophagyanddownstreamsignalingpathways.

Results:Oxymatrinereducedmyocardialischemia-reperfusioninjurybydownregulatingtheexpressionofiRhom2mediatedbyNF-κB,andregulatediRhom2affectingtheexpressionlevelsofMMP-9,Bax,Bcl-2andtheoccurrenceofcellapoptosis,thusexertingaprotectiveeffect.

Conclusion:OxymatrinecanregulateiRhom2-mediatedendothelialcellautophagyanddownstreamsignalingpathwaystoalleviatemyocardialischemia-reperfusioninjury.

Keywords:oxymatrine;iRhom2;myocardialischemia-reperfusioninjury;endothelialcell;cellapoptosisMyocardialischemia-reperfusioninjuryisacommoncomplicationofmyocardialinfarctionandcardiacsurgery,anditisamajorcauseofmorbidityandmortalityworldwide.Despiteadvancesinmedicaltechnology,thereisstillnoeffectivetreatmentformyocardialischemia-reperfusioninjury.

Inrecentyears,autophagyhasemergedasanoveltargetforthetreatmentofmyocardialischemia-reperfusioninjury.Autophagyisacellularprocessthatdegradesdamagedorunwantedcellularcomponentsandrecyclestheresultingproductsforenergyproduction.Autophagyplaysacrucialroleinmaintainingcellularhomeostasisandprotectingcellsfromvariousstresses,includinghypoxiaandnutrientdeprivation.

Endothelialcellsaretheprimarytargetofmyocardialischemia-reperfusioninjury,andtheirdysfunctioncontributestothepathogenesisofthiscondition.iRhom2isamemberoftherhomboidfamilyofproteinsthatisexpressedinendothelialcellsandplaysaroleinregulatingtheexpressionofvarioussignalingmoleculesinvolvedincellsurvival,proliferation,andapoptosis.

OxymatrineisanaturalcompoundderivedfromtheplantSophoraflavescens,andithasbeenshowntopossessanti-inflammatory,anti-oxidative,andanti-apoptoticeffectsinvariouscelltypes.Inthisstudy,weinvestigatedtheroleofoxymatrineinregulatingiRhom2-mediatedendothelialcellautophagyanditsdownstreamsignalingpathwaysinthecontextofmyocardialischemia-reperfusioninjury.

Ourresultsshowedthatoxymatrinetreatmentsignificantlyimprovedmyocardialfunctionandreducedmyocardialinfarctsizeinaratmodelofmyocardialischemia-reperfusioninjury.OxymatrinetreatmentalsoincreasedtheexpressionofautophagymarkersinendothelialcellsandreducedtheexpressionofiRhom2,whichwasmediatedbyNF-κBsignaling.

FurtheranalysisrevealedthatoxymatrinetreatmentregulatediRhom2expression,whichinturnaffectedtheexpressionlevelsofMMP-9,Bax,Bcl-2,andtheoccurrenceofcellapoptosis,thusexertingaprotectiveeffectagainstmyocardialischemia-reperfusioninjury.

Inconclusion,ourfindingssuggestthatoxymatrinecanregulateiRhom2-mediatedendothelialcellautophagyanddownstreamsignalingpathwaystoalleviatemyocardialischemia-reperfusioninjury.Theseresultsprovidenewinsightsintothepathogenesisofthisconditionandmaypavethewayforthedevelopmentofnoveltherapeuticstrategiesforthetreatmentofmyocardialischemia-reperfusioninjuryBasedonourfindings,weproposethatfutureresearchonmyocardialischemia-reperfusioninjuryshouldfocusonfurtherelucidatingthemolecularmechanismsunderlyingiRhom2-mediatedendothelialcellautophagyanditsimpactondownstreamsignalingpathways.Additionally,investigatingthepotentialclinicalapplicationsofoxymatrineasatherapeuticagentforthisconditioniswarranted.

Furthermore,ourstudyhighlightstheimportanceofidentifyingnoveltargetsandtherapeuticstrategiesforthetreatmentofmyocardialischemia-reperfusioninjury.Currently,treatmentsforthisconditionarelimitedtoreperfusiontherapyandpharmacologicalinterventionstoalleviatesymptomsandreducecomplications.However,improvingourunderstandingofthemolecularmechanismsinvolvedinmyocardialischemia-reperfusioninjuryandidentifyingnewtherapeutictargetsmayleadtothedevelopmentofmoreeffectivetreatmentswithfewersideeffects.

Overall,ourstudyprovidesnewinsightsintothepathogenesisofmyocardialischemia-reperfusioninjuryandhighlightsthepotentialofoxymatrineasatherapeuticagentforthiscondition.FutureresearchshouldfocusonfurtherelucidatingthemolecularmechanismsunderlyingthisconditionandidentifyingnewtargetsandtherapeuticstrategiesthatcanimproveclinicaloutcomesforpatientsMyocardialischemia-reperfusioninjury(MIRI)isacomplexprocessthatinvolvesmultiplepathwaysandcellularprocesses,suchasapoptosis,inflammation,oxidativestress,andmitochondrialdysfunction.WhilecurrenttreatmentsforMIRImainlyinvolvereperfusionstrategiesandsupportivecare,thereisagrowingneedformoreeffectiveandtargetedtherapiesthatcanmitigatethedamagecausedbyMIRIandimproveclinicaloutcomesforpatients.

OnepromisingavenuefordevelopingnewtherapiesforMIRIistoidentifykeymoleculartargetsandpathwaysthatareinvolvedinthepathogenesisofthiscondition.Inrecentyears,agrowingbodyofevidencehassuggestedthatreactiveoxygenspecies(ROS)andinflammationplaykeyrolesinMIRI,andthattargetingthesepathwaysmayleadtothedevelopmentofmoreeffectivetreatmentswithfewersideeffects.

Forexample,studieshaveshownthatROS,includingsuperoxideanionandhydrogenperoxide,aregeneratedduringreperfusionandcancauseoxidativedamagetocellularcomponents,suchaslipids,proteins,andDNA.This,inturn,cantriggeracascadeofeventsthatleadtoinflammation,celldeath,andtissuedamage.Therefore,antioxidanttherapies,suchastheuseofsuperoxidedismutase(SOD),catalase,orvitaminC,havebeenproposedaspotentialtreatmentsforMIRI.

InadditiontoROS,inflammationisalsoakeycontributortoMIRI.Duringischemiaandreperfusion,thereleaseofproinflammatorycytokines,suchastumornecrosisfactor-alpha(TNF-α),interleukin-1beta(IL-1β),andinterleukin-6(IL-6),canactivateimmunecellsandattractthemtotheinjuredtissue.This,inturn,cancausefurtherdamagetothetissuebyinducingoxidativestress,apoptosis,andnecrosis.Therefore,anti-inflammatorytherapies,suchastheuseofnonsteroidalanti-inflammatorydrugs(NSDs),corticosteroids,orcytokineinhibitors,havealsobeenproposedaspotentialtreatmentsforMIRI.

Whilethesestrategieshaveshownsomepromiseinpreclinicalstudies,theirclinicalefficacyandsafetyprofileremaintobefullyevaluated.Moreover,thereisagrowingneedtoidentifynewtargetsandtherapiesthatcancomplementorenhancetheseexistingapproaches.

Onesuchtargetthathasreceivedattentioninrecentyearsisthetransientreceptorpotentialvanilloid1(TRPV1)channel.TRPV1isanonselectivecationchannelthatisexpressedinavarietyoftissues,includingtheheart,andisinvolvedinpainsignaling,inflammation,andoxidativestress.StudieshaveshownthatTRPV1isupregulatedduringMIRIandthatitsactivationcanexacerbatetissuedamagebypromotinginflammationandoxidativestress.Therefore,blockingTRPV1maybeapromisingstrategyforreducingtissuedamageandimprovingclinicaloutcomesinMIRI.

SeveralcompoundsthatcanmodulateTRPV1activityhavebeenidentified,includingthenaturalproductoxymatrine.OxymatrineisabioactivealkaloidthatisextractedfromtherootoftheChineseherbSophoraflavescensandhasbeenusedintraditionalChinesemedicineforthousandsofyears.Inrecentyears,oxymatrinehasbeenshowntohaveantioxidant,anti-inflammatory,andcardioprotectiveeffectsinvariouspreclinicalmodelsofcardiovasculardisease,includingMIRI.

Studieshaveshownthatoxymatrinecanreduceinfarctsize,improvecardiacfunction,andinhibitapoptosisandinflammationinanimalmodelsofMIRI.OxymatrinehasbeenshowntoexertitseffectsbyinhibitingTRPV1activation,suppressingoxidativestress,andregulatingtheexpressionofpro-andanti-inflammatorycytokines.

Whilethesefindingsarepromising,moreresearchisneededtofullyunderstandthemolecularmechanismsunderlyingthecardioprotectiveeffectsofoxymatrineandtooptimizeitsuseasatherapeuticagentforMIRI.Inparticular,futurestudiesshouldfocusonevaluatingthesafetyandefficacyofoxymatrineinclinicaltrialsandidentifyingnewtargetsandtherapeuticstrategiesthatcanworksynergisticallywithoxymatrinetoimproveclinicaloutcomesforpatientswithMIRI.

Insummary,MIRIisacomplexprocessthatinvolvesmultiplepathwaysandcellularprocesses,manyofwhicharemediatedbyROSandinflammation.Targetingthesepathwaysusingantioxidantoranti-inflammatorytherapieshasshownsomepromise,butmoreresearchisneededtooptimizetheiruseandidentifynewtargetsandtherapies.Oxymatrine,aninhi