Bone Marrow Cells Take On New Role In The Brain

韩雪娜

日期: 2003-02-05 今日/总浏览: 1/499
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ResearchersintheBaxterLaboratoryatStanfordUniversityMedicalCenterhavepublishednewevidenceshowingthatcellsfromthebonemarrowmighthelprepairormaintaincellsinothertissues.Inapaperinthisweek'sonlineeditionoftheProceedingsoftheNationalAcademyofSciences,theresearchersdescribefindingchromosomesfromabonemarrowtransplantinthebraincellsoftransplantrecipients.
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Whenpeoplereceiveabonemarrowtransplantafterhigh-dosechemotherapy,someofthetransplantedcellsregeneratetheblood-makingcellsthatweredestroyed.Inpastexperimentsinmice,HelenBlau,PhD,theDonaldE.andDeliaB.BaxterProfessorofPharmacologyattheSchoolofMedicine,foundthatcellsfromthetransplantcouldalsorelocatetotissuesthroughoutthebodyratherthanbeingrestrictedtothebonemarrowandblood.
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Nowweknowthatitcanalsohappeninhumans,saidJamesWeimann,PhD,firstauthoronthepaperandaseniorresearchscientistinBlau'slab.2 @: ]5 U* w  i* M
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BlauandWeimannlookedatbrainsamplestakenfromwomenwhounderwentchemotherapytotreattheirleukemiaandthenlaterreceivedbonemarrowtransplantsfrommaledonors.ThesesampleswereidealforthisexperimentbecausethedonorcellscontainedaYsexchromosomewhereascellsinthewomencontainedonlyXchromosomes.AnyYchromosomethatBlauandWeimannidentifiedmusthavecomefromthetransplantdonor.
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/ w: g: B) Y& }( |1 J7 a9 HTolookforthetelltaleYchromosome,theresearchersusedmoleculeswithadoubleidentity.OnepartofthemoleculecouldbindtoeithertheXorYchromosome,whiletheotherpartactedasafluorescentmolecularbeacon.ThemoleculethatboundtheXchromosomehadaredbeaconwhereastheY-recognizingmoleculehadagreenbeacon.Whentheyputthesestainsonthepreservedsamples,theXchromosomesglowedredandanyYchromosomesglowedgreen.Weimannthensearchedthesamplesunderamicroscopeforgreenchromosomesinthebraintissue.
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5 \5 _2 l! _' z2 z. ~# E. X& k3 l' ~' @* `! eAsexpected,bloodcellswithinthebraincontainedYchromosomesbecausetheyweremadebybonemarrowcellsfromthetransplant.TheresearchersalsofoundfivenervecellscalledPurkinjecells-involvedincontrollingbalanceandmovement-thatcontainedYchromosomesinadditiontotheiroriginalXchromosomes.Theseout-of-placechromosomescouldonlyhavecomefrommalecellsinthebonemarrowtransplant.1 ^3 N  J5 i- V! J6 O7 e+ W5 g, f
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BlaususpectsthePurkinjecellsmayhavegottentheirYchromosomefromagroupoftravelingbonemarrowcells.Ithinkthesecellsmayactasarepairsquad,Blausaid.Thecellstravelthebloodstream,respondtostressandrepairdamagedtissuessuchasbrain,muscleandpossiblyothersthroughoutthebody.Sheaddedthatinsomecasesthebonemarrowcellsmightfusewithdamagedcellswhileinotherinstancestheytransformtoreplacethecells.
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Shesaidthenextstepsaretolearnwhichcellsinthebonemarrowactastherepairsquad,howthesecellsareluredtotissuesandhowtheyrepairdamageoncetheygetthere.Ifwecanlearnwhatthesignalsare,wemaybeabletodirecttherepaircellstowheretheyareneeded,Blausaid.Wouldn'titbeterrificifwecouldenlistthebodytotreatitsowndisease?
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Blauaddedthatadultbonemarrowcellsmaybeparticularlyusefulfortreatingsomediseasesorsometissuesbutnotothers.Weneedtostudyalltypesofstemcells,shesaid.% K) ^$ v* Z# o0 }
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OtherStanfordresearcherswhocontributedtothisworkincludeCarolCharlton,PhD,aresearchassociate,andgraduatestudentTimothyBrazelton,PhD.
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# Q, r; `9 ~& b( u8 a, ?1 H来源: Stanford University Medical Center( c( S' L4 N3 b1 C  I
发布者: 刘斌