ObjectivesToinvestigatetheanti-apoptoticeffectsofmesenchymalstemcells(MSCs)onhypoxicinjuredcardiacmyocytesinvitro.MethodsMSCswereisolatedfrombonemarrowofSprague-Dawley(SD)rats,andcardiacmyocytesfromneonatalrats.Theratcardiacmyocyteswereco-culturedwithMSCsorMSC-conditionedmediainanoxia(95%N2+5%CO2)for72hours.CellapoptosiswasmeasuredbyHoechst33258staining.TheexpressionofBcl-2andBaxincardiacmyocyteswastestedbyWesternBlot.ResultsTheapoptoticratewas51.6%±2.4%whencardiacmyocyteswereculturedincontinuoushypoxiaandwassignificantlydecreasedwhencardiacmyocyteswerecoculturedwithMSCsorMSC-conditionedmedia(15.1%±5.4%and24.0%±4.2%respectively,P<0.001).ThedecreasedexpressionofBaxinthecardiacmyocyteswasgreatlyrelatedtothedecreasingofapoptosis,buttherewasnodifferenceinBcl-2expressionamongthesegroups.ConclusionsCo-culturedMSCsshowedsignificantanti-apoptoticeffectsoncardiacmyocytesincontinuoushypoxia.ThemechanismmaybetheinteractofcelltocellandparacrineofcytokineswhicheffectedtheexpressionofBaxinthecardiacmyocytes.
