It’s been just over 15 years since James Thomson first isolated embryonic stem cells in his lab at the University of Wisconsin-Madison. In that time, some remarkable advances have been made. Namely, I’m talking about the ability to transform adult human cells into extremely useful pluripotent stem cells.
A new treatment using pluripotent cells could potentially repair and regenerate damaged heart tissue. In a 2013 study published in The Lancet, Dr. Eduardo Marban, director of the Cedars Sinai Heart Institute, treated 17 heart attack patients with an injection of heart cells grown from their stem cells. A year after the procedure, scar tissue on the hearts had shrunk by about 50%.
This sounds promising, but stem cells have not been approved to treat any heart disease in the United States. The field is young and researchers have just begun to scratch the surface of understanding. Some studies show little or no improvement, but others have shown dramatically improved heart function.
Stem cells do a fairly good job. But they can be coaxed to work harder and longer. For reasons still not totally understood, the body stops dispatching stem cells to repair the heart about a week after the damage has occurred. Researchers are still working to overcome this and many other challenges.
Scientists still have many more mysteries to unlock before stem cell therapy for damaged hearts can be proven fully safe and beneficial. For example, getting stem cells to stay put amidst the high pressure flow rate inside a beating heart and on tissue scarred by a heart attack remain challenges in need of a more refined solution.
Video courtesy Xiaojun Lian, department of chemical and biological engineering, UW-Madison
Cardiomyocytes, the beating, muscle cells of the heart, can be made from stem cells in the laboratory to model heart disease and test drugs. Researchers are trying to prove that they can be used for cell replacement and other treatments.