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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4 \$ l; t9 S& O0 \8 cResearchersintheBaxterLaboratoryatStanfordUniversityMedicalCenterhavepublishednewevidenceshowingthatcellsfromthebonemarrowmighthelprepairormaintaincellsinothertissues.Inapaperinthisweek'sonlineeditionoftheProceedingsoftheNationalAcademyofSciences,theresearchersdescribefindingchromosomesfromabonemarrowtransplantinthebraincellsoftransplantrecipients.$ ]; f3 \8 C; c% k9 g

$ l. \8 l% h3 I) A& n) ]; L, }Whenpeoplereceiveabonemarrowtransplantafterhigh-dosechemotherapy,someofthetransplantedcellsregeneratetheblood-makingcellsthatweredestroyed.Inpastexperimentsinmice,HelenBlau,PhD,theDonaldE.andDeliaB.BaxterProfessorofPharmacologyattheSchoolofMedicine,foundthatcellsfromthetransplantcouldalsorelocatetotissuesthroughoutthebodyratherthanbeingrestrictedtothebonemarrowandblood.9 F4 `( p  F7 |; w4 }1 x

- h" Q5 r2 @, N( t. WNowweknowthatitcanalsohappeninhumans,saidJamesWeimann,PhD,firstauthoronthepaperandaseniorresearchscientistinBlau'slab.
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( X4 w# I  e/ z  c% ^9 BBlauandWeimannlookedatbrainsamplestakenfromwomenwhounderwentchemotherapytotreattheirleukemiaandthenlaterreceivedbonemarrowtransplantsfrommaledonors.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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- b  X. W7 D6 L0 j7 kBlaususpectsthePurkinjecellsmayhavegottentheirYchromosomefromagroupoftravelingbonemarrowcells.Ithinkthesecellsmayactasarepairsquad,Blausaid.Thecellstravelthebloodstream,respondtostressandrepairdamagedtissuessuchasbrain,muscleandpossiblyothersthroughoutthebody.Sheaddedthatinsomecasesthebonemarrowcellsmightfusewithdamagedcellswhileinotherinstancestheytransformtoreplacethecells.( I; \0 Q1 @  w0 s* H
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Shesaidthenextstepsaretolearnwhichcellsinthebonemarrowactastherepairsquad,howthesecellsareluredtotissuesandhowtheyrepairdamageoncetheygetthere.Ifwecanlearnwhatthesignalsare,wemaybeabletodirecttherepaircellstowheretheyareneeded,Blausaid.Wouldn'titbeterrificifwecouldenlistthebodytotreatitsowndisease?
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Blauaddedthatadultbonemarrowcellsmaybeparticularlyusefulfortreatingsomediseasesorsometissuesbutnotothers.Weneedtostudyalltypesofstemcells,shesaid.
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& Q+ o, X8 b  H. \1 H/ B# sOtherStanfordresearcherswhocontributedtothisworkincludeCarolCharlton,PhD,aresearchassociate,andgraduatestudentTimothyBrazelton,PhD.
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) B& b5 L' E/ ^来源: Stanford University Medical Center$ }' @! i& d  s; }/ D1 t
发布者: 刘斌