BSCRC member W. Robb MacLellan and colleagues uncovered for the first time why adult human cardiac myocytes have lost their ability to proliferate, perhaps explaining why the human heart has little regenerative capacity.

The study, done in cell lines and mice, may lead to methods of reprogramming a patient’s own cardiac myocytes within the heart itself to create new muscle to repair damage, said Dr. Robb MacLellan, a researcher with the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA and senior author of the study.

Unlike newts and salamanders, human adults cannot spontaneously regrow damaged organs such as the heart. However, recent research suggests that mammals do have the ability to regenerate the heart for a very brief period, about the first week of life. But that ability is quickly lost. But if we had it once, MacLellan said, maybe it is possible to regain that ability.

Published in the Aug. 8 issue of the peer-reviewed Journal of Cell Biology, MacLellan’s study suggests it might be possible to turn back the cellular clock to a time when cardiac myocytes had the ability to proliferate and re-grow heart muscle.