That means the amount of carbon-14 in DNA can serve as a date mark for when a cell was born.
Frisén and colleagues extracted DNA from the nuclei of heart cells in 14 patients who had died while at the Karolinska Institute, as well as from samples from the U.K. Human Tissue Bank, according to the study, to be published tomorrow in the journal Science.
All the tissues sampled were from people born up to 22 years before the onset of the 1950s nuclear tests.
The results showed that some heart cells had higher carbon-14 concentrations, suggesting that the cells had been created any years after birth.
(See heart photos.)
Other organs in the body also regenerate, most of them faster, study co-author Frisén added. For instance, all of a person's white blood cells regenerate over the course of a year.
Beyond Stem Cells
The finding may be promising for creating new drugs or other medical treatments that could boost heart cell growth in people with heart troubles, Frisén said.
For instance, people with heart injuries recover very slowly, probably because their heart cells are not regenerating fast enough.
Currently, regenerative treatments involve taking cells from other organs or bone marrow and injecting them into the heart, said the American Heart Association's Tomaselli, who also works at Johns Hopkins University in Baltimore.
Stem cell treatments are another option, but just getting the cells and preparing them is "complicated and expensive and fraught with a lot of side effects," Tomaselli said.
The new discovery may allow treatments that can "marshal forces and try to get cells to turn over in a more rapid rate in situ," Tomaselli said.
Meanwhile, study co-author Frisén and his team have already taken up a new project: Looking at whether a slower-than-normal regrowth rate of heart cells could portend disease.
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