Bone Marrow Cells Take On New Role In The Brain

韩雪娜

日期: 2003-02-05 今日/总浏览: 1/4997 W: _! @/ X6 i" l- R; W0 M6 j; _

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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 e6 ^, s! b- ]( \
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BlauandWeimannlookedatbrainsamplestakenfromwomenwhounderwentchemotherapytotreattheirleukemiaandthenlaterreceivedbonemarrowtransplantsfrommaledonors.ThesesampleswereidealforthisexperimentbecausethedonorcellscontainedaYsexchromosomewhereascellsinthewomencontainedonlyXchromosomes.AnyYchromosomethatBlauandWeimannidentifiedmusthavecomefromthetransplantdonor.
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TolookforthetelltaleYchromosome,theresearchersusedmoleculeswithadoubleidentity.OnepartofthemoleculecouldbindtoeithertheXorYchromosome,whiletheotherpartactedasafluorescentmolecularbeacon.ThemoleculethatboundtheXchromosomehadaredbeaconwhereastheY-recognizingmoleculehadagreenbeacon.Whentheyputthesestainsonthepreservedsamples,theXchromosomesglowedredandanyYchromosomesglowedgreen.Weimannthensearchedthesamplesunderamicroscopeforgreenchromosomesinthebraintissue.
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Asexpected,bloodcellswithinthebraincontainedYchromosomesbecausetheyweremadebybonemarrowcellsfromthetransplant.TheresearchersalsofoundfivenervecellscalledPurkinjecells-involvedincontrollingbalanceandmovement-thatcontainedYchromosomesinadditiontotheiroriginalXchromosomes.Theseout-of-placechromosomescouldonlyhavecomefrommalecellsinthebonemarrowtransplant.
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BlaususpectsthePurkinjecellsmayhavegottentheirYchromosomefromagroupoftravelingbonemarrowcells.Ithinkthesecellsmayactasarepairsquad,Blausaid.Thecellstravelthebloodstream,respondtostressandrepairdamagedtissuessuchasbrain,muscleandpossiblyothersthroughoutthebody.Sheaddedthatinsomecasesthebonemarrowcellsmightfusewithdamagedcellswhileinotherinstancestheytransformtoreplacethecells.
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Shesaidthenextstepsaretolearnwhichcellsinthebonemarrowactastherepairsquad,howthesecellsareluredtotissuesandhowtheyrepairdamageoncetheygetthere.Ifwecanlearnwhatthesignalsare,wemaybeabletodirecttherepaircellstowheretheyareneeded,Blausaid.Wouldn'titbeterrificifwecouldenlistthebodytotreatitsowndisease?* J  P8 [( g$ f" h: _+ Y5 D+ K7 S
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Blauaddedthatadultbonemarrowcellsmaybeparticularlyusefulfortreatingsomediseasesorsometissuesbutnotothers.Weneedtostudyalltypesofstemcells,shesaid.
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OtherStanfordresearcherswhocontributedtothisworkincludeCarolCharlton,PhD,aresearchassociate,andgraduatestudentTimothyBrazelton,PhD.
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来源: Stanford University Medical Center$ `8 f6 ^: L* B- l% N( q8 X
发布者: 刘斌