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.
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BlauandWeimannlookedatbrainsamplestakenfromwomenwhounderwentchemotherapytotreattheirleukemiaandthenlaterreceivedbonemarrowtransplantsfrommaledonors.ThesesampleswereidealforthisexperimentbecausethedonorcellscontainedaYsexchromosomewhereascellsinthewomencontainedonlyXchromosomes.AnyYchromosomethatBlauandWeimannidentifiedmusthavecomefromthetransplantdonor., B6 x6 h7 o, _6 e& p. t4 c
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TolookforthetelltaleYchromosome,theresearchersusedmoleculeswithadoubleidentity.OnepartofthemoleculecouldbindtoeithertheXorYchromosome,whiletheotherpartactedasafluorescentmolecularbeacon.ThemoleculethatboundtheXchromosomehadaredbeaconwhereastheY-recognizingmoleculehadagreenbeacon.Whentheyputthesestainsonthepreservedsamples,theXchromosomesglowedredandanyYchromosomesglowedgreen.Weimannthensearchedthesamplesunderamicroscopeforgreenchromosomesinthebraintissue.- X0 Y6 s2 E2 I& M4 k4 \8 j

" N2 |- h4 P% H: l8 gAsexpected,bloodcellswithinthebraincontainedYchromosomesbecausetheyweremadebybonemarrowcellsfromthetransplant.TheresearchersalsofoundfivenervecellscalledPurkinjecells-involvedincontrollingbalanceandmovement-thatcontainedYchromosomesinadditiontotheiroriginalXchromosomes.Theseout-of-placechromosomescouldonlyhavecomefrommalecellsinthebonemarrowtransplant.  x; @# K) u- {4 V) \7 H
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BlaususpectsthePurkinjecellsmayhavegottentheirYchromosomefromagroupoftravelingbonemarrowcells.Ithinkthesecellsmayactasarepairsquad,Blausaid.Thecellstravelthebloodstream,respondtostressandrepairdamagedtissuessuchasbrain,muscleandpossiblyothersthroughoutthebody.Sheaddedthatinsomecasesthebonemarrowcellsmightfusewithdamagedcellswhileinotherinstancestheytransformtoreplacethecells.1 a- [: s& J- K8 z

5 O! p( u5 B$ g; \/ W; sShesaidthenextstepsaretolearnwhichcellsinthebonemarrowactastherepairsquad,howthesecellsareluredtotissuesandhowtheyrepairdamageoncetheygetthere.Ifwecanlearnwhatthesignalsare,wemaybeabletodirecttherepaircellstowheretheyareneeded,Blausaid.Wouldn'titbeterrificifwecouldenlistthebodytotreatitsowndisease?/ Z' i1 Q; n2 m! y/ V$ F
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Blauaddedthatadultbonemarrowcellsmaybeparticularlyusefulfortreatingsomediseasesorsometissuesbutnotothers.Weneedtostudyalltypesofstemcells,shesaid.
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OtherStanfordresearcherswhocontributedtothisworkincludeCarolCharlton,PhD,aresearchassociate,andgraduatestudentTimothyBrazelton,PhD.7 v( L+ H( H* e
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作者:
. V0 Q% h: d* N6 n2 p6 E来源: Stanford University Medical Center& G: t0 X& o, I9 o2 J
发布者: 刘斌