Fig. 1

a Study of cardiac morphology after induction with different epigenetic modifiers. Differentiation was performed with DC301, DC302, and DC303, and various combinations of these inhibitors, and the appearance of cardiac morphology was assessed by phase-contrast microscopy (scale bars = 100 μm, n = 3). Treatment with DC301 + DC302 indicates clear cardiac morphology (scale bar = 50 μm). b Analysis of cardiac markers by quantitative RT-PCR after cardiac induction with different epigenetic modifiers. Cardiac-specific genes GATA4, Nkx2.5, MLC, TnT, and cardiac actin were studied for their expression after cardiac induction with DC301, DC302, and DC303, and various combinations of these inhibitors as indicated. Results are mean ± SD of three independent experiments performed in triplicate (*p < 0.05, **p < 0.01, n = 3). c Structural markers of cardiomyocytes identified by immunocytochemistry using antibodies against cardiac actin (scale bars = 100 μm), GATA4, TnT, desmin, and troponin I, and visualized using fluorescence microscopy (scale bars = 50 μm, n = 3). d Markers of noncardiac lineages studied by qRT-PCR, which showed no change in osterix, PPARγ, and collagen II levels after treatment of WJMSCs with DC301 + DC302. e Flow cytometric analysis performed to quantify TnI-positive cells in WJMSC-derived cardiomyocytes. ANP atrial natriuretic peptide, TnI troponin I, TnT troponin T, WJMSC Wharton’s jelly mesenchymal stem cell