干细胞之家 - 中国干细胞行业门户第一站
标题:
Stem Cells Reverse Diabetes in Mice
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作者:
bobo
时间:
2008-12-31 00:22
标题:
Stem Cells Reverse Diabetes in Mice
日期: 2003-07-23 今日/总浏览: 1/567
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Bone marrow stem cells (green) induce the regeneration of insulin-producing islet cells of the pancreas (red) in mice. Scale bar, 50 micrometers.Nonobese diabetic mouse.
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Researchershavecureddiabetesinmicebyinjectingbonemarrowstemcellsintothebloodstream.Thestemcellsseekoutdamagedtissueinthepancreas,wheretheyappeartotriggerthegrowthofnewcells.Ifbonemarrowstemcellshavethesameeffectinhumanswithdiabetes,theycouldbeusedtotreatpatientsstraightaway.
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“Thisisaverysignificantstudy,”saysJoelHabenerofHarvardMedicalSchoolinBoston,whostudiesstemcellsinthepancreas.“Itsuggeststhatthereissomethinginthebonemarrowthatcanstimulatethepancreaticstemcellstoregenerate.”
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Itcantakedecadestobringanewdrugtothemarketplace.Butbonemarrowtransplantshavebeenusedforyearstotreatahostofblooddisorders,includingleukemiaandsicklecelldisease.Theyhavebeenprovensafeandwouldrequirenogovernmentapprovalforuseasapossiblediabetestreatmentinhumans.
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“There’snothingtopreventpeoplefromtryingthisinhumans,”saysHabener.“Peoplewithdiabeteshavebeenwaitingforacureforyearsandyears.Whynotgoaheadandtry?”
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Diabetes,whichaffects150millionpeopleworldwide,occurswhenthepancreasdoesnotproduceenoughinsulinorwhencellsofthebodybecomeresistanttoinsulin.Asaresult,glucoseaccumulatesinthebloodstream,leadingtoseverecomplications,includingheartdisease,nervedamage,stroke,blindness,andkidneyfailure.
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Inthenewstudy,MickieBhatiaandhiscolleaguesatRobartsResearchInstituteinLondon,Ontario,firsttreatedmicewithadrugthatdestroysthepancreasandmakesthemdiabetic.Thediabeticmicehadlowlevelsofinsulinandhighlevelsofglucoseintheirblood.
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Butwhentheresearchersinjectedthemicewithbonemarrowstemcells,thesymptomsofdiabetesreversedwithin2weeks.Insulinlevelsroseandbloodglucoselevelsfelltonear-normalvalues.
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Labelingofthedonorcellsrevealedthatthenewcellgrowthhadcomefromcellsalreadywithinthepancreas,notfromtheinjectedcells.
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“Wealmostdidn’tbelievetheresultsourselves,”saysBhatia.“Wehavehadtheresultsforafewyears,butheldbackpublishingthem.Butit’saconsistentrobusteffect.”
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Theresearchersalsofoundthattheinjectedbonemarrowcellstriggerednewgrowthonlyindamagedpancreatictissue.Inmicewithintactpancreases,noregenerationoccurred.
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“Bonemarrowcellsonlygotothepancreasifit’sinjured,”saysBhatia.“Somethingattheinjurysitecausesthestemcellstohomeintothedamagedpancreas.Wehavenoideawhatthatcouldbe.”
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Otherstudieshaveshownrecentlythatbonemarrowstemcellscanbecomedifferentkindsofcellsinthebody,includingheart,liver,pancreas,andnerve.Butthesefindingshavebeencontroversial.Someexperimentssuggestthatthestemcellscanthemselvesbeturnedintodifferenttypesofcells,whileotherssuggestthatthechangeoccursbecausethecellsfusetoformhybridcells.
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Bhatia’sstudyisdifferentbecauseitsuggeststhatthebonemarrowstemcellsdonotthemselvesbecomepancreascells.Instead,thecellssomehowstimulatenewgrowthincellsthatarealreadyinthepancreas.
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Justhowthisoccursisnotknown,butHabenerbelievesthatbonemarrowcellsaresecretingsomekindofsignalthattellsstemcellsinthepancreastogrow.
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Ifresearcherscouldisolatethesubstancethattriggerstheregenerationofpancreascellstotreatdiabetes,itcouldbegivendirectlytopatients,thusavoidingtransplants.
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“Wecouldjustgiveashotofthisstemcellstimulator,andthepancreascouldmakenewcells,”saysHabener.“Itwouldbeawonderfulwaytotreatthedisease.”
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作者: Nancy Touchette
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来源: Genome News Network
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发布者: 刘斌
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