Heart infarction is one of the major death causing diseases in the Chinese urban population. Up to date, there is no effective therapy on this disease. Human embryonic stem cell based cardiac repair is one of the most promising strategies to cure this disease. Under the current technology, human embryonic stem cells can indiscriminate differentiate into embryonic atrial, ventricular myocytes and pacing making cells. Because each subtype of cardiomyocytes has its unique electrophysiological properties, transplantation of these mixed cardiomyocytes could cause several arrhythmias, and raise the risk of future cardiac cell repair therapy. One solution for this problem is to direct differentiate human embryonic stem cells into either atrial or ventricular myocytes, and use the homogenous cardiac populations to fix the damaged atria or ventricle.

In the research article published at the November 23, 2010, Drs. Yue Ma and Guangju Ji reported their discoveries that retinoid signals control the atrial versus ventricular myocytes fate specification during human embryonic stem cell differentiation. Using the technology developed in Dr. Ma’s lab, human embryonic stem cells can be directly differentiated into either atrial myocytes or ventricular myocyte in 14 days. These cells process the electrophysiological properties of embryonic atrial or ventricular myoctes. This discovery make it possible that large amount of human atrial and ventricular myocytes be generated in laboratory, and have a significant impact on the drug development and heart regeneration. It is one major step closer toward successfully regenerating the heart, and developing cardiac repair therapies for heart infarction. This work was published on Cell Research online AOP. 

1. Beating embryonic ventricular myocytes differentiated from human embryonic stem cells (note: slow beating rate)

2. Beating embryonic atrial myocytes differentiated from human embryonic stem cells (note: fast beating rate)

3. Beating embryonic ventricular myocytes differentiated from human embryonic stem cells (note: with low magnification )