FLICKR, GEORGE SHULKINC-kit cells, which are found in the heart and supposedly act as cardiac stem cells, are the basis of a clinical trial to repair cardiac injury. But a new study published in Nature today (May 7) adds what some researchers are calling “definitive” evidence to the idea that these cells hardly ever produce new heart muscle in vivo. Using genetic lineage tracing in a mouse, a team led by Jeff Molkentin of Cincinnati Children’s Hospital Medical Center found that, while c-kit cells readily produce cardiac endothelium, they very rarely generate cardiomyocytes.
“The conclusion I am led to from this is that the c-kit cell is not a cardiac stem cell, at least in term of its normal, in vivo role,” said Charles Murry, a heart regeneration researcher at the University of Washington who was not involved in this study.
The latest findings add to a string of recent setbacks for advancing the use of these cells as a therapy—including a retraction and an expression of concern regarding two publications and an institutional investigation of one of the leaders in the field, Piero Anversa at Harvard Medical School. “There’s been a tidal wave in the last few weeks of rising skepticism,” said Eduardo Marbán, an author of the new study and a cardiologist at the Cedars-Sinai Heart ...
