Xenografted Human Amniotic Membrane–Derived Mesenchymal Stem Cells Are Immunologically Tolerated and Transdifferentiated Into Cardiomyocytes

Rationale: Amniotic membrane is known to have the ability to transdifferentiate into multiple organs and is expected to stimulate a reduced immunologic reaction. Objective: Determine whether human amniotic membrane–derived mesenchymal cells (hAMCs) can be an ideal allograftable stem cell source for cardiac regenerative medicine. Methods and Results: We established hAMCs. After cardiomyogenic induction in vitro, hAMCs beat spontaneously, and the calculated cardiomyogenic transdifferentiation efficiency was 33%. Transplantation of hAMCs 2 weeks after myocardial infarction improved impaired left ventricular fractional shortening measured by echocardiogram (34±2% [n=8] to 39±2% [n=11]; P P Conclusions: Because hAMCs have a high ability to transdifferentiate into cardiomyocytes and to acquire immunologic tolerance in vivo, they can be a promising cellular source for allograftable stem cells for cardiac regenerative medicine.