Retinoic-acid-concentration-dependent acquisition of neural cell identity during in vitro differentiation of mouse embryonic stem cells

摘要

Retinoicacid(RA)isoneofthemostimportantmorphogens,anditsembryonicdistributioncorrelateswithneuraldifferentiationandpositionalspecificationinthedevelopingcentralnervoussystem.Toinvestigatetheconcentration-dependenteffectsofRAonneuraldifferentiationofmouseembryonicstemcells(EScells),weinvestigatedthepreciseexpressionprofilesofneuralandregionalspecificgenesbyEScellsaggregatedintoembryoidbodies(EBs)exposedtovariousconcentrationsofRAortheBMPantagonistNoggin.RApromotedbothneuraldifferentiationandcaudalizationinaconcentration-dependentmanner,andtheconcentrationofRAwasfoundtoregulatedorso-ventralidentity,i.e.,higherconcentrationsofRAinducedadorsalphenotype,andlowerconcentrationsofRAinducedamoreventralphenotype.TheinductionofthemoreventralphenotypewasduetothehigherexpressionleveloftheN-terminusofsonichedgehogprotein(Shh-N)whentreatedwithlowconcentrationRA,asitwasabrogatedbyaninhibitorofShhsignaling,cyclopamine.ThesefindingssuggestthattheconcentrationofRAstrictlyandsimultaneouslyregulatestheneuralizationandpositionalspecificationduringdifferentiationofmouseEScellsandthatitmaybepossibletouseittoestablishastrategyforcontrollingtheidentityofES-cell-derivedneuralcells./p/div