Study Of Rat Bone Marrow Mesenchymal Stem Cells (BMSCs) Differentiating Into Cardiomyocyte-like In Vitro

Background The treatment of ischemic heart disease by myocardial regenerationhas been the focus of research at home and abroad. BMSCs is easy to be obtained,amplified in vitro under certain conditions and autologous transplantation. There isno ethical controversy、immune rejection and differentiating into endothelial cells,osteoblasts, cardiomyocytes cells in vitro and in vivo induction conditions [1-4]. Thestudy found that BMSCs can differentiate into cardiomyocyte-like cells in vivo and invitro induced environment, but its mechanism is not clear[5-7]. The rat BMSCs with5-aza-induced or myocardial cells co-cultured in vitro in this experimental to observethe growth and morphological changes induced differentiation of rat BMSCs and theirdifferentiation into cardiomyocyte-like cells in different time periods and the expressionof specific markers of myocardial cells of cTnI, Cx43and cardiac-specific transcriptionfactor GATA-4difference, providing the theoretical basis and technical means for thefuture research on the BMSCs differentiation machines and to be used in clinicaltreatment of ischemic heart disease. Objective To study the ability of rat bone marrow mesenchymal stem cells (BMSCs)differentiate into cardiomyocyte-like cells in vitro inducing conditions and differencesin expression of specific markers of myocardial cells in different periods.Methods To isolate and culture the SD rat BMSCs、SD neonatal rat CM andidentified. The3rd generation of BMSCs is be induced respectively by5-azacytidine(5-aza)、co-culture with CM and cultured alone. Using an inverted microscope toobserve cell growth and morphological changes at2,4,6,8,10weeks, and each set ofcardiac-specific genes of cTnI、Cx43and cardiac-specific transcription factor GATA-4.was detected by RT-PCR.Results There is no expression of cTnI、Cx43、GATA-4gene and pulsating cells incultured alone group;5-Aza induced cell group fusiform and arranged in the directionconsistent in the first two weeks, and no pulsating cells. cTnI、Cx43gene expression isup to peak in the first eight weeks. GATA-4gene expression to the peak in the fourweeks; Co-cultured cells are mostly fusiform myoblasts arranged visible、 theinconsistent frequency pulsating throb cells, cTnI, Cx43gene expression graduallyincreased in the first2-8weeks, GATA-4gene expression reach to peak in the first sixweeks. The expression of GATA-4、cTnI and Cx43gene are (P <0.05) higher than the5-aza induced in the same period within co-culture group. The three groups of cellsdisintegrating cell death with prolonged incubation time began to increase,12weeks oftraining is particularly evident.Conclusion BMSCs induced by5-aza or co-cultured with CM can be transformed intocardiomyocyte-like cells and expression of the cTnI Cx43and GATA-4gene, and theBMSCs co-cultured cells group has more ability to differentiate into cardiomyocyte-likecells than5-aza induced group.Myocardial microenvironment may promote bonemarrow mesenchymal stem cells to differentiate into cardiomyocyte-like cells.