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
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, N- o% C5 s5 k" p3 L" L4 NSkeletalmusclehasaremarkablecapacitytoregeneratefollowingexerciseorinjuryandharborstwodifferenttypesofadultstemcellstoaccomplishthejob:satellitecellsandadultstemcellsthatcanbeisolatedassidepopulation(SP)cells.Acertaingroupofthesestemcellsisinvolvedinmuscletissuerepair,butisonlytriggeredintothemusclecelldevelopmentpathwaybyinjury.Thequestionthenarises:whatmolecularfactorsturntheseadultstemcellsintomusclecells?NowMichaelRudnickiandcolleagueshaveshownthatonegene,Pax7,hasacrucialroleinthisprocess.
! ]1 _# b* n# A5 x7 Q0 FInpreviousstudies,Rudnicki’sgroupdemonstratedthatPax7isrequiredtoturnadultstemcellsintomusclecellsduringregeneration.Here,theresearchersworkedwithmousemodelsandinvitroexperimentstoinvestigatewhetherPax7issufficienttoinitiatemusclecellformationininjuredtissue.7 b) y* @4 d, K6 V7 c
TheyshowthatstemcellstakenfromregeneratingmuscleinmicelackingthePax7genecouldnotbecomemusclecells,andthatbyputtingPax7backintostemcellstakenfromuninjuredmuscle,theycangenerateapopulationofcellsthatreadilydifferentiateintomusclecells.WhenstemcellsengineeredtoexpressPax7proteinswereinjectedintothemusclesofmicelackingdystrophin(theproteindefectiveinmusculardystrophy),thecellsdifferentiated,formingdystrophin-expressingmusclecellsinthedefectivemuscle.Thisshowsthatengineereddonorcellscandifferentiateinlivingtissueandhelprepairdamagedmuscleofrecipientmice.WhentheresearchersinjectedPax7(usingagenetherapyvirus)intothedamagedmuscleofmicelackingPax7,theyobservedtheproductionofmuscle-formingcellsthatnotonlygaverisetodifferentiatedmusclecells,butalsoaidedintissuerepair., \3 Z* V2 I! G" {) a
TheresearchersarguethattheseresultsunequivocallyestablishPax7asakeyregulatorofmusclecelldifferentiationinspecificpopulationsofadultstemcellsduringmuscletissueregenerationinmice.IftherapeuticstrategiesthatactivatePax7inadultstemcellscanturnthemintomusclecells,effectivelyreplenishinginjuredordiseasedmuscletissue,there’shopeofreversingthedebilitatingeffectsofprogressivemuscle-wastingdiseases.Thoughtheusefulnessofsuchanapproachinhumanswillrequireintensiveinvestigation,theresultsonthesemouseadultstemcellsareencouraging.  t) C' f' j0 ^( Y% q& p! U

& L- o3 p& v3 m* y' ACitation:SealeP,IshibashiJ,ScimA,RudnickiMA(2004)Pax7isnecessaryandsufficientforthemyogenicspecificationofCD45 :Sca1 stemcellsfrominjuredmuscle.PLoSBiol2(5):e130DOI:10.1371/journal.pbio.0020130
/ f6 y% p& V8 q& t! E        Moreinformation:        http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020130% H3 ?' ?1 q- ?1 H2 \0 v

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, K6 o6 a  q: ^  N发布者: 刘斌