Embryonic Stem Cells Treat Infarcted Rat Hearts
Purified human cardiomyocytes derived from embryonic stem cells improve the animals' cardiac function following transplantation
TUESDAY, Aug. 28 (HealthDay News) -- Transplanted heart cells derived from human embryonic stem cells improve heart function in rats, suggesting that similar transplants could benefit humans after a heart attack, according to a report published online Aug. 26 in Nature Biotechnology.
Charles E. Murry, M.D., Ph.D., of the University of Washington in Seattle, and colleagues used a scalable system for directed differentiation that relies on activin A and bone morphogenetic protein-4 (BMP4) to generate highly purified human heart cells (cardiomyocytes) derived from embryonic stem cells. They also identified a cocktail of pro-survival factors that limits cardiomyocyte death after transplantation. The researchers injected the cardiomyocytes into rats that had been subjected to experimental heart attacks.
After four weeks, the investigators found that the injections resulted in consistent formation of myocardial grafts in the infarcted rat heart, improved cardiac function and slowed the progression of heart failure.
"The most important observation in the present study is that engraftment of human embryonic stem cell-derived cardiomyocytes improved cardiac function. This raises questions about the mechanisms underlying this effect. The most straightforward explanation is that the implanted human cardiomyocytes beat synchronously with the host myocardium and thereby directly contribute systolic force," the authors write. "The ability of human embryonic stem cell-derived cardiomyocytes to partially remuscularize myocardial infarcts and attenuate heart failure encourages their study under conditions that closely match human disease," the authors conclude.