成体干细胞再生损伤肌肉

bobo

日期: 2004-05-12 今日/总浏览: 1/559
3 J. _1 v+ P( s) I$ x# F
, @8 L% e6 B4 r$ t& }+ l
: ?2 p- O) c- [$ `, p# }" R5 S& l4 h8 |0 F3 V
% S7 L1 y( x2 Z2 ^/ G! m. I
$ U+ _9 c' A: x/ K
( A/ E% {+ h) K& w9 }4 ]
  ~- N. t* N" E
Skeletalmusclehasaremarkablecapacitytoregeneratefollowingexerciseorinjuryandharborstwodifferenttypesofadultstemcellstoaccomplishthejob:satellitecellsandadultstemcellsthatcanbeisolatedassidepopulation(SP)cells.Acertaingroupofthesestemcellsisinvolvedinmuscletissuerepair,butisonlytriggeredintothemusclecelldevelopmentpathwaybyinjury.Thequestionthenarises:whatmolecularfactorsturntheseadultstemcellsintomusclecells?NowMichaelRudnickiandcolleagueshaveshownthatonegene,Pax7,hasacrucialroleinthisprocess.
1 _+ v, w  ^7 H/ H9 X5 yInpreviousstudies,Rudnicki’sgroupdemonstratedthatPax7isrequiredtoturnadultstemcellsintomusclecellsduringregeneration.Here,theresearchersworkedwithmousemodelsandinvitroexperimentstoinvestigatewhetherPax7issufficienttoinitiatemusclecellformationininjuredtissue.
9 l* ]2 A3 s6 I( [5 wTheyshowthatstemcellstakenfromregeneratingmuscleinmicelackingthePax7genecouldnotbecomemusclecells,andthatbyputtingPax7backintostemcellstakenfromuninjuredmuscle,theycangenerateapopulationofcellsthatreadilydifferentiateintomusclecells.WhenstemcellsengineeredtoexpressPax7proteinswereinjectedintothemusclesofmicelackingdystrophin(theproteindefectiveinmusculardystrophy),thecellsdifferentiated,formingdystrophin-expressingmusclecellsinthedefectivemuscle.Thisshowsthatengineereddonorcellscandifferentiateinlivingtissueandhelprepairdamagedmuscleofrecipientmice.WhentheresearchersinjectedPax7(usingagenetherapyvirus)intothedamagedmuscleofmicelackingPax7,theyobservedtheproductionofmuscle-formingcellsthatnotonlygaverisetodifferentiatedmusclecells,butalsoaidedintissuerepair.
, s6 ]+ Y7 _2 {) \% d, i$ e. iTheresearchersarguethattheseresultsunequivocallyestablishPax7asakeyregulatorofmusclecelldifferentiationinspecificpopulationsofadultstemcellsduringmuscletissueregenerationinmice.IftherapeuticstrategiesthatactivatePax7inadultstemcellscanturnthemintomusclecells,effectivelyreplenishinginjuredordiseasedmuscletissue,there’shopeofreversingthedebilitatingeffectsofprogressivemuscle-wastingdiseases.Thoughtheusefulnessofsuchanapproachinhumanswillrequireintensiveinvestigation,theresultsonthesemouseadultstemcellsareencouraging.* M- c2 z8 O/ V$ S, v/ x, y2 E5 J
- ?5 q2 D7 e1 p
Citation:SealeP,IshibashiJ,ScimA,RudnickiMA(2004)Pax7isnecessaryandsufficientforthemyogenicspecificationofCD45 :Sca1 stemcellsfrominjuredmuscle.PLoSBiol2(5):e130DOI:10.1371/journal.pbio.0020130
; j- P  D' o4 R' J        Moreinformation:        http://www.plosbiology.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020130
# L* J1 g7 C- k4 _6 t# |4 w3 z, X3 \$ O. a
9 ~& i# }6 V; I! S! p# t
, ^# }! u, @' [% \" B
& y  A" o, z8 T

$ m% m4 ~. z+ M; `& X" Q作者: 1 T. x& j+ f, J/ i4 }
来源: 0 @' j+ J8 J# Y* Z- g
发布者: 刘斌