成体干细胞再生损伤肌肉

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日期: 2004-05-12 今日/总浏览: 1/559* h/ o( ]9 q9 Y

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Skeletalmusclehasaremarkablecapacitytoregeneratefollowingexerciseorinjuryandharborstwodifferenttypesofadultstemcellstoaccomplishthejob:satellitecellsandadultstemcellsthatcanbeisolatedassidepopulation(SP)cells.Acertaingroupofthesestemcellsisinvolvedinmuscletissuerepair,butisonlytriggeredintothemusclecelldevelopmentpathwaybyinjury.Thequestionthenarises:whatmolecularfactorsturntheseadultstemcellsintomusclecells?NowMichaelRudnickiandcolleagueshaveshownthatonegene,Pax7,hasacrucialroleinthisprocess.
/ D. N: S1 V) OInpreviousstudies,Rudnicki’sgroupdemonstratedthatPax7isrequiredtoturnadultstemcellsintomusclecellsduringregeneration.Here,theresearchersworkedwithmousemodelsandinvitroexperimentstoinvestigatewhetherPax7issufficienttoinitiatemusclecellformationininjuredtissue.. j$ c, P+ x! U5 V( i
TheyshowthatstemcellstakenfromregeneratingmuscleinmicelackingthePax7genecouldnotbecomemusclecells,andthatbyputtingPax7backintostemcellstakenfromuninjuredmuscle,theycangenerateapopulationofcellsthatreadilydifferentiateintomusclecells.WhenstemcellsengineeredtoexpressPax7proteinswereinjectedintothemusclesofmicelackingdystrophin(theproteindefectiveinmusculardystrophy),thecellsdifferentiated,formingdystrophin-expressingmusclecellsinthedefectivemuscle.Thisshowsthatengineereddonorcellscandifferentiateinlivingtissueandhelprepairdamagedmuscleofrecipientmice.WhentheresearchersinjectedPax7(usingagenetherapyvirus)intothedamagedmuscleofmicelackingPax7,theyobservedtheproductionofmuscle-formingcellsthatnotonlygaverisetodifferentiatedmusclecells,butalsoaidedintissuerepair." o0 t* S- M  ]$ h$ b
TheresearchersarguethattheseresultsunequivocallyestablishPax7asakeyregulatorofmusclecelldifferentiationinspecificpopulationsofadultstemcellsduringmuscletissueregenerationinmice.IftherapeuticstrategiesthatactivatePax7inadultstemcellscanturnthemintomusclecells,effectivelyreplenishinginjuredordiseasedmuscletissue,there’shopeofreversingthedebilitatingeffectsofprogressivemuscle-wastingdiseases.Thoughtheusefulnessofsuchanapproachinhumanswillrequireintensiveinvestigation,theresultsonthesemouseadultstemcellsareencouraging.
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Citation:SealeP,IshibashiJ,ScimA,RudnickiMA(2004)Pax7isnecessaryandsufficientforthemyogenicspecificationofCD45 :Sca1 stemcellsfrominjuredmuscle.PLoSBiol2(5):e130DOI:10.1371/journal.pbio.0020130
: y: ]! \6 R' K8 `. g+ W. d  S        Moreinformation:        http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020130
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发布者: 刘斌