InductionofMarrowMesenchymalStemCellstoCardiomyocytesinvitroandimmunologicpropertiesofdifferentiatedmesenchymalstemcellsIntroductionBACKGROUNDMakinosuccessfulinductedcutivatedrat’sMSCintocardiomyocytesinvitroin1999BartholomewconfirmedthatMSCfailedtoelicitaproliferativeresponseofallogeneiclymphocytesin2002Lately,ithasbeenprovedthattheculturedcellsinducedintofat,boneandgristlecan’texpressMHCIImoleculeandfailedtoelicitaproliferativeresponseofallogeneiclymphocytesinmixedlymphocytereactionQuestion:ObjectiveMethodsTheculturedcellswereinducedintocardiomyocytesby5-AZAinvitroTheculturedcellswereevaluatedbyimmunohistochemicalstainingfor,cardiac-specifictroponinT(cTnT)andmyosinheavychain(MHC)TheMSCdifferentiationwasalsoobservedbyRT-PCRTheimmunologicpropertiesofMSCafterdifferentiationandthefeasibilityoftreatmentofmyocardialinfarctionbyexogenousstemcellsPartoneFlowchartMaterialsandmethodsMSCweretreatedwith10µmol/lof5-azacytidinefor24htoinducecelldifferentiationTheshapeofMSCwereobservedbyInverted-typephase-contrastvideomicroscopeReversetranscriptaseRT-PCRofcardiomyocyte-specificgenes,includingatrialnatriureticpeptide(ANP)andMHCPCRprimersusedinthisstudyInternalLaneStandardglyceraldehyde-3-phosphate-dehydroge-nase,(GAPDH)5′-CATCACCATCTTCCAGGAGCC-35′-TGACCTTGCCCACAGCCTTG-3′443bpANPprimer5′-GGCTCCTTCTCCATCACCAA-3′5′-TGTTATCTTCGGTACTGGCG-3′327bp(+4~+461bp)βMHCprimer5′-ATCCTGCCCTCTGCCTTT3′5′-GTGAAGGTGGGCAACGAA3′538bp(+6~+452bp)ResultsImmunohistochemicalmethodsindicatedtheexpressionsofMHCandcTnTrespectivelyNegativecomparison（×100）RTPCRanalysisofexpressionofcardiomyocytespecificgenes:ANPDISCUSSION5-AZAplaythedeterminingroleinthecardiomygenicdifferatiationofMSCTheinducedeffectdependedontheamountof5-AZADNAdemethvlatingagentQuestionsParttwoAnimalsWistarratsMetiaralRPMI-1640fetalbovineserumFicoll3H-TDRGlassfiberfilterTomtecharvestingmachineluminenscencecounterFlowchartCellscultureMixedlymphocytecultureResearchexvivoMethods-MixedCellCulture