Development of Efficient Cardiac Differentiation Method of Mouse Embryonic Stem Cells

To obtain an enhanced population of cardiomyocytes from differentiating mouse embryonic stem (ES) cells, we confirmed the role of noggin treatment during the cardiac differentiation of mouse ES cells. ES cells were cultured in ES medium containing both noggin and LIF for 3 days on the mouse embryonic fibroblast feeder layer, followed by dissociated and suspension culture without LIF to form the embryoid body (EB). The next day, noggin was eliminated and EBs were cultured continuously. Noggin treated ES cells showed a relatively rapid increase of cardiac marker genes, while the vehicle (PBS) treated group showed no significant cardiac marker expression at 4 days after the EB formation. Furthermore, Noggin treated ES cells showed 68.00±9.16% spontaneous beating EBs at 12 days after the EB formation. To develop a more efficient cardiomyocyte differentiation method, we tested several known cardiogenic reagents (ascorbic acid, 5’-Azacytidine, LiCl, oxytocin, FGF2 and PDGF-BB) after noggin induction or we cultured noggin treated ES cells on various extracellular matrixes (collagen, fibronectin and Matrigel). Quantitative RT-PCR and immunocytochemistry results showed a significantly increased cardiac differentiation rate in the FGF2 treated group. Differentiation on the collagen extracellular matrix (ECM) could slightly increase the cardiac differentiation efficiency. These results show the possibilities for the establishment of selective differentiation conditions for the cardiac differentiation of mouse ES cells.