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: 1/4609 a5 a6 q6 M* [" ^& g

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+ P; D, [% ~8 s7 a- ?Yourseven-year-old'sbabytoothmaybeworthalotmorethanthequarterthetoothfairyleftunderthepillow.Scientistshavediscoveredthatthepulpinsidedeciduousteethisatreasuretroveoffast-growingstemcells.Naturally-shedchopperscouldthusprovideaneasilyaccessiblenewsourceofthesesought-aftercellsforclinicalstudiesofstem-celltransplantationandtissueengineering.- n& {1 C5 i9 g  r
Whenhissix-year-olddaughterpulledoutherbabytooth,SongtaoShioftheNationalInstituteofDentalandCraniofacialResearchinBethesda,Md.,washeditofftoprepareitforthetoothfairy.Holdinghisdaughter'spartialtooth,thestemcellresearchernoticedlivingtissueinsideandwonderedwhetheritmightcontainrelativelyyoungstemcells.Shitookthetoothtohislabandfoundthathewasindeedabletoisolatesuchcellsfromthetoothpulpleftinthecrown.
7 g: q1 I( w1 J( O, FExtractingmorestemcellsfromthelostbabyteethofseven-andeight-year-olds,ShicalledthenewgroupofcellsSHED(stemcellsfromhumanexfoliateddeciduousteeth).Inthelab,theculturedcellsgrewquickly,formingsphere-likeclustersindicativeofafastrateofproliferationnotobservedinstemcellsisolatedfrombonemarroworadultteeth.Notonlydidtheygrowrapidly,butwhenimplantedundertheskinofimmunocompromisedmice,SHEDinducedboneformation--afeatthatstemcellsextractedfromadultwisdomteethcouldnotaccomplish.SHEDcellsalsotriggeredneuralcellformationinthebrainandfatcellgrowth;stemcellsfromadultteeth,ontheotherhand,arenotasgoodatneuralcellgenerationandcannottriggerfatcellgrowthatall.AreportdescribingthesefindingswaspublishedonlinethisweekbytheProceedingsoftheNationalAcademyofSciences.
0 U, W# }* b1 v! w; M' lOneofthechallengesofstemcellresearchisthatnobodyquiteknowstheextenttowhichtheycanbeusedtoinducegrowthintissuesotherthanthatfromwhichtheywereextracted.Inthatregard,SHEDcellscouldpotentiallyworkbetterthanothertypesofstemcellsbecauseoftheiryouth(andthusfastproliferation)andtheirdemonstratedabilitytoinducethegrowthofseveraltypesofcells.Whenkids'teethfalloutwecansavethem,Shiremarks.Iftheyneed[thestemcellsfrom]themin20years,therewillbenoimmunorejection.Justwhatthoseneedsmightbe,Shicannotsay.Butconsideringthatotherresearchersarealreadyfreezingstemcellsfromumbilicalcords,hemuses,Whydon'twesavethisone?; Q- O% m, H; X$ [4 F* A

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作者:
9 t) k' _, e! \% @来源: Scientific American
# c8 k& C' U, a2 x# r1 k发布者: 亦云