LOS ANGELES, Aug. 8 (UPI) -- U.S. researches say adult human cardiac cells lose their ability to proliferate, perhaps explaining why the human heart has little regenerative capacity.
Stem cell researchers at UCLA say the discovery may lead to methods of reprogramming a patient's cardiac myocytes, or muscle cells, within the heart itself to create new muscle to repair damage.
Recent research suggests mammals have the ability to regenerate the heart for a very brief period, about the first week of life, but the ability is quickly lost, a UCLA release said Monday.
The UCLA 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.
Some animals like newts and salamanders can spontaneously regrow damaged organs such as the heart at any point in their life, the researchers say.
During human development, progenitor stem cells create cardiac myocytes that proliferate to form the heart, but once the heart is formed the myocytes transform from immature cells into mature cells that cannot proliferate.
In newts and salamanders cardiac myocytes can go back and forth between immature, or primitive, states to proliferate and repair damage and then revert back into mature cells once the damage is repaired.
"In mammals, we've lost that potential," UCLA study leader Robb MadLellan said. "If we knew how to restore that, or knew the reason why adult myocytes can't do it, we could try to figure out a way to use nature's methods to regenerate the heart."