Co-culture with cardiomyocytes induces mesenchymal stem cells to differentiate into cardiomyocyte-like cells and express heart development-associated genes

【摘要】：正Recent studies have demonstrated that bone marrow mesenchymal stem cells(MSCs) have the potential to transdifferentiate into cardiomyocytes(CMs) in an appropriate condition both in vivo and in vitro,and our previous studies also confirmed it.However,there exists a controversy among a variety of studies about whether MSCs can differentiate into CMs without physical contacts with CMs,and the molecular signals that underlie this process are not fully understood.In the present study,MSCs isolated from adult rats were cocultured with CMs obtained from neonatal rat ventricles at 1:5 ratio in a dual chamber dish separated by a semipermeable membrane for 2 weeks.During this non-direct contact coculture procedure,cardiomyogenic differentiation and relative genes expression in MSCs were evaluated. After coculture with CMs,MSCs showed a stick-like or elliptical morphology.Immunofluorescent stain results revealed that a -actin and cardiac troponin T(cTnT) positive cells were found in MSCs at 5 days after coculture with CMs,and 29.63%of MSCs were positive forα-actin and 27.38%for cTnT at 14 days. Results from RT-PCR demonstrated the expression level of TGF-β,Nkx-2.5,GATA-4 and MEF-2C genes began to increase at 1 day and reached the peak at 7 days after coculture.In conclusion,non-direct contact with CMs(1:5) is conducive for MSCs to differentiate into CMs in vitro,and TGF-β,Nkx-2.5, GATA-4 and MEF-2C genes may play a crucial role during the transdifferentiation.