LSD1抑制介導(dǎo)脊髓損傷早期神經(jīng)元自噬影響調(diào)亡的實(shí)驗(yàn)研究

LSD1抑制介導(dǎo)脊髓損傷早期神經(jīng)元自噬影響調(diào)亡的實(shí)驗(yàn)研究摘要：

長(zhǎng)鏈非編碼RNA調(diào)節(jié)蛋白1(LSD1)是一種與神經(jīng)元自噬和細(xì)胞凋亡密切相關(guān)的蛋白。本研究旨在探究LSD1是否介導(dǎo)脊髓損傷(SM)早期神經(jīng)元自噬影響調(diào)亡，以期為神經(jīng)系統(tǒng)損傷治療提供新思路。采用大鼠SM模型，結(jié)合行為學(xué)、免疫組化、熒光定量PCR、Westernblot,electronmicroscopy等多種實(shí)驗(yàn)手段，研究LSD1的表達(dá)、神經(jīng)元自噬、凋亡以及細(xì)胞核內(nèi)甲基化等相關(guān)變化。結(jié)果顯示，SM早期，LSD1表達(dá)顯著升高，伴隨著神經(jīng)元自噬和細(xì)胞凋亡的增加，脊髓神經(jīng)元核內(nèi)甲基化水平降低。應(yīng)用化學(xué)藥劑抑制LSD1后發(fā)現(xiàn)，LSD1抑制可以顯著抑制SM早期神經(jīng)元凋亡，且據(jù)文獻(xiàn)報(bào)道，LSD1抑制可誘導(dǎo)細(xì)胞自噬，對(duì)神經(jīng)元自噬的影響也值得研究。但本文的數(shù)據(jù)不支持LSD1介導(dǎo)神經(jīng)元自噬，進(jìn)一步研究可考慮LSD1在細(xì)胞凋亡通路其他分子途徑中介的作用。綜上所述，本研究表明LSD1介導(dǎo)SM早期神經(jīng)元凋亡的發(fā)生，抑制LSD1可為提高神經(jīng)元存活率提供新的治療方案。

關(guān)鍵詞：LSD1,自噬,細(xì)胞凋亡,脊髓損傷(SM)

Abstract：

Lysine-specificdemethylase1(LSD1)isaproteincloselyrelatedtoneuronalautophagyandapoptosis.ThisstudyaimstoinvestigatewhetherLSD1mediatestheeffectofearlynervecellautophagyonapoptosisafterspinalcordinjury(SCI),inordertoprovidenewideasforthetreatmentofneurologicaldamage.UsingaratmodelofSCI,acombinationofbehavioraltests,immunohistochemistry,quantitativePCR,Westernblotanalysis,electronmicroscopy,andotherexperimentalmethods,theexpressionofLSD1,neuronalautophagy,apoptosis,andnuclearmethylationchangeswerestudied.TheresultsshowedthatLSD1expressionsignificantlyincreasedintheearlystageofSCI,accompaniedbyanincreaseinneuronalautophagyandapoptosis,andadecreaseinnuclearmethylationlevelsinspinalcordneurons.ItwasfoundthatpharmacologicalinhibitionofLSD1significantlyinhibitedtheearlyapoptosisofnervecellsafterSCI.Accordingtopreviousliteraturereports,LSD1inhibitioncaninduceautophagyincells,butthisstudydidnotfindthatLSD1mediatesneuronalautophagy.Therefore,furtherresearchcanconsidertheroleofLSD1inothermolecularpathwaysofthecellapoptosispathway.Insummary,thisstudyshowsthatLSD1isinvolvedintheearlyapoptosisofspinalcordneuronsafterSCI,andtheinhibitionofLSD1mayprovideanewtherapeuticstrategytoimproveneuronalsurvival.

Keywords:LSD1,autophagy,apoptosis,spinalcordinjury(SCISpinalcordinjury(SCI)isadevastatingeventthatoftenleadstoirreversibledamageandfunctionalimpairments.OneofthemajorcausesofsecondarydamageafterSCIisneuronalapoptosis.Therefore,identifyingthemolecularmechanismsofneuronalapoptosisanddevelopingtherapeuticstrategiestopreventorreduceapoptosisarecriticalforpromotingneuronalsurvivalandimprovingfunctionaloutcomesafterSCI.

Inrecentyears,therehasbeengrowinginterestintheroleofhistonemethylationinregulatinggeneexpressionandcellularprocesses,includingapoptosis.LSD1,alsoknownasKDM1A,isalysine-specificdemethylasethatremovesmono-anddi-methylgroupsfromhistoneH3lysine4(H3K4)andregulatesgenetranscription.SeveralstudieshavereportedtheinvolvementofLSD1invariouscellularprocesses,includingdifferentiation,proliferation,andapoptosis.However,theroleofLSD1inneuronalapoptosisafterSCIisnotwellunderstood.

Inthisstudy,theresearchersinvestigatedtheexpressionandroleofLSD1intheapoptosisofspinalcordneuronsafterSCI.UsingaratmodelofSCI,theyfoundthatLSD1expressionwassignificantlyupregulatedinthespinalcordtissueat24hoursafterinjury.Furthermore,immunofluorescencestainingrevealedthatLSD1wasmainlyexpressedinneuronsandcolocalizedwithcaspase-3,akeyexecutorofapoptosis.

TofurtherinvestigatetheroleofLSD1inneuronalapoptosisafterSCI,theresearchersusedaspecificinhibitorofLSD1,tranylcypromine(TCP),toblockLSD1activityinvitroandinvivo.TheyfoundthatTCPtreatmentsignificantlyreducedthenumberofTUNEL-positiveapoptoticcellsandincreasedtheexpressionoftheanti-apoptoticproteinBcl-2inthespinalcordtissueafterSCI.Moreover,TCPtreatmentimprovedthefunctionaloutcomesoftherats,asassessedbytheBasso,Beattie,andBresnahan(BBB)locomotorscale.

Interestingly,theresearchersalsoinvestigatedtheroleofLSD1inautophagy,acellularprocessthatdisposesofdamagedorganellesandproteinsandpromotescellsurvival.TheyfoundthatLSD1inhibitiondidnotinduceautophagyinspinalcordneuronsafterSCI,suggestingthatLSD1mediatesneuronalapoptosisthroughothermolecularpathways.

Inconclusion,thisstudyprovidesevidencethatLSD1isinvolvedintheearlyapoptosisofspinalcordneuronsafterSCIandthatLSD1inhibitionmayprovideanewtherapeuticstrategytoimproveneuronalsurvival.FutureresearchcanfurtherinvestigatethemolecularmechanismsbywhichLSD1regulatesapoptosisandidentifyotherpotentialtargetsfortherapeuticinterventionsafterSCIFurtherstudiescanalsoexploretheoptimaltimeanddosageforLSD1inhibitiontherapyafterSCI,aswellasitspotentialeffectsonmotorfunctionrecoveryandtissuerepair.

Moreover,thisstudyprovidesanewperspectiveontheroleofhistonedemethylationinmediatingneuronalapoptosisafterSCI.WhilepreviousstudiesmainlyfocusedontheinvolvementofhistoneacetylationandDNAmethylation,thisstudysuggeststhathistonedemethylationmayalsoplayacriticalroleinregulatinggeneexpressionandcellfateafterSCI.

Overall,thisstudyshedslightonthepotentialtherapeuticbenefitsofLSD1inhibitioninSCIandhighlightstheneedforfurtherresearchtofullyelucidateitsmolecularmechanismsandclinicalapplications.WiththedevelopmentofmorespecificandeffectiveLSD1inhibitors,itispossibletotranslatethesefindingsintoclinicalpracticeandimprovethelong-termoutcomesofSCIpatientsInadditiontothepotentialtherapeuticbenefitsofLSD1inhibition,itisimportanttoconsiderthelimitationsandchallengesindevelopingthisapproachforSCItreatment.OnemajorchallengeisthespecificityofLSD1inhibitors,astheymayalsoaffectotherhistonedemethylasesorothercellularpathwaysleadingtooff-targeteffects.Thus,itiscrucialtodevelopmoreselectiveandspecificLSD1inhibitorstominimizeadverseeffects.

AnotherchallengeisthecomplexityofSCIpathophysiology,whichinvolvesmultiplecellularandmolecularmechanisms.LSD1inhibitionmaybeeffectiveintargetingonespecificaspectofSCI,suchasneuronalsurvivalorglialscarformation,butmaynotbesufficienttoaddressallaspectsofSCI.Therefore,combinationtherapiestargetingmultiplepathwaysmaybenecessaryforeffectiveSCItreatment.

Inaddition,theoptimaltiminganddurationofLSD1inhibitionafterSCIrequiresfurtherinvestigation.ThestudybyWuetal.demonstratedtheefficacyofLSD1inhibitioninpromotingneuronalsurvivalandreducingglialscarformationwhenadministeredsoonafterSCI.However,thelong-termeffectsofLSD1inhibitionandthepotentialconsequencesofchronicinhibitionrequirefurtherstudy.

Furthermore,theuseofLSD1inhibitioninSCItreatmentraisesethicalandsafetyconcerns,asitinvolvesthemanipulationofgeneexpressioninlivingorganisms.Therefore,itisimportanttoconsiderthepotentialrisksandbenefitsofLSD1inhibitionandtoensurethatitisusedsafelyandresponsibly.

Inconclusion,thestudybyWuetal.highlightsthepotentialtherapeuticbenefitsofLSD1inhibitioninSCIandprovidesinsightsintoitsmolecularmechanisms.LSD1inhibitionoffersapromisingapproachforpromotingneuronalsurvivaland