婴幼儿牙齿可能成为新的干细胞来源

韩雪娜

日期: 2003-04-23 今日/总浏览: 1/460$ P5 |2 ?: W2 ~9 z0 [

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4 o1 r; {. P/ g; e# PYourseven-year-old'sbabytoothmaybeworthalotmorethanthequarterthetoothfairyleftunderthepillow.Scientistshavediscoveredthatthepulpinsidedeciduousteethisatreasuretroveoffast-growingstemcells.Naturally-shedchopperscouldthusprovideaneasilyaccessiblenewsourceofthesesought-aftercellsforclinicalstudiesofstem-celltransplantationandtissueengineering.
! }- y' d7 e( C! m, ~. x! s  P" u  ZWhenhissix-year-olddaughterpulledoutherbabytooth,SongtaoShioftheNationalInstituteofDentalandCraniofacialResearchinBethesda,Md.,washeditofftoprepareitforthetoothfairy.Holdinghisdaughter'spartialtooth,thestemcellresearchernoticedlivingtissueinsideandwonderedwhetheritmightcontainrelativelyyoungstemcells.Shitookthetoothtohislabandfoundthathewasindeedabletoisolatesuchcellsfromthetoothpulpleftinthecrown.( I7 n- Z$ K5 L/ z8 h/ u$ I" Z$ V
Extractingmorestemcellsfromthelostbabyteethofseven-andeight-year-olds,ShicalledthenewgroupofcellsSHED(stemcellsfromhumanexfoliateddeciduousteeth).Inthelab,theculturedcellsgrewquickly,formingsphere-likeclustersindicativeofafastrateofproliferationnotobservedinstemcellsisolatedfrombonemarroworadultteeth.Notonlydidtheygrowrapidly,butwhenimplantedundertheskinofimmunocompromisedmice,SHEDinducedboneformation--afeatthatstemcellsextractedfromadultwisdomteethcouldnotaccomplish.SHEDcellsalsotriggeredneuralcellformationinthebrainandfatcellgrowth;stemcellsfromadultteeth,ontheotherhand,arenotasgoodatneuralcellgenerationandcannottriggerfatcellgrowthatall.AreportdescribingthesefindingswaspublishedonlinethisweekbytheProceedingsoftheNationalAcademyofSciences.
7 \, \+ N2 _$ ]* _6 i$ IOneofthechallengesofstemcellresearchisthatnobodyquiteknowstheextenttowhichtheycanbeusedtoinducegrowthintissuesotherthanthatfromwhichtheywereextracted.Inthatregard,SHEDcellscouldpotentiallyworkbetterthanothertypesofstemcellsbecauseoftheiryouth(andthusfastproliferation)andtheirdemonstratedabilitytoinducethegrowthofseveraltypesofcells.Whenkids'teethfalloutwecansavethem,Shiremarks.Iftheyneed[thestemcellsfrom]themin20years,therewillbenoimmunorejection.Justwhatthoseneedsmightbe,Shicannotsay.Butconsideringthatotherresearchersarealreadyfreezingstemcellsfromumbilicalcords,hemuses,Whydon'twesavethisone?
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作者: + |3 A& L! a$ N/ B% G8 s% h$ a" n
来源: Scientific American# P  w" t+ U% G& s7 I+ v
发布者: 亦云