LSD1抑制介导脊髓损伤早期神经元自噬影响调亡的实验研究

LSD1抑制介导脊髓损伤早期神经元自噬影响调亡的实验研究摘要：

长链非编码RNA调节蛋白1(LSD1)是一种与神经元自噬和细胞凋亡密切相关的蛋白。本研究旨在探究LSD1是否介导脊髓损伤(SM)早期神经元自噬影响调亡，以期为神经系统损伤治疗提供新思路。采用大鼠SM模型，结合行为学、免疫组化、荧光定量PCR、Westernblot,electronmicroscopy等多种实验手段，研究LSD1的表达、神经元自噬、凋亡以及细胞核内甲基化等相关变化。结果显示，SM早期，LSD1表达显著升高，伴随着神经元自噬和细胞凋亡的增加，脊髓神经元核内甲基化水平降低。应用化学药剂抑制LSD1后发现，LSD1抑制可以显著抑制SM早期神经元凋亡，且据文献报道，LSD1抑制可诱导细胞自噬，对神经元自噬的影响也值得研究。但本文的数据不支持LSD1介导神经元自噬，进一步研究可考虑LSD1在细胞凋亡通路其他分子途径中介的作用。综上所述，本研究表明LSD1介导SM早期神经元凋亡的发生，抑制LSD1可为提高神经元存活率提供新的治疗方案。

关键词：LSD1,自噬,细胞凋亡,脊髓损伤(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