Evaluation of In Vitro Differentiation of Cardiomyocyte-like cells Derived from Human Bone Marrow Mesenchymal Stem Cells

Purpose: To investigate the in vitro differentiation process of cardiomyocyte-like cells derived from human bone marrow mesenchymal stem cells under the influence of 5-azacytidine (5-aza). Materials and Methods: After purification, human bone marrow mesenchymal stem cells were exposed to 5-aza at a concentration of 5 μmol for 5 weeks to induce cardiomyocyte differentiation. To induce differentiation, the culture medium of human bone marrow mesenchymal stem cells was changed consecutively every 24 hours, so that the cells were placed in culture medium without and with 5-aza for 24 hours. This process continued until the sampling. To evaluate the cell differentiation process by comparing the pattern and mRNA expression of cardiac specific genes including actinin alpha, myosin heavy chain and connexin-43 by RT-PCR at the end of the first to fifth weeks after induction.The expression of actinin specific proteins Alpha, cardiac troponin and connexin-43 were used at the end of the third and fifth weeks after induction by flow cytometry. Results: The mRNAs of the examined genes were expressed in a time-dependent pattern, so that the mRNAs of α-actinin and Connexin-43 genes were expressed in an upward trend in all samples from the first to the fifth week, and also the expression of MHC mRNAs showed the highest rate on the 4th week. Expression of actin-alpha and cardiac troponin proteins was equal in the third and fifth weeks after induction, but the population of cells expressing connexin-43 protein increased from the third to the fifth week. Conclusion: The present study showed that mesenchymal stem cells can differentiate into cardiomyocytes under the influence of 5-aza at a concentration of 5 μmol. Also, with increasing induction time, cardiomyocytes become more developed.