The Scars That Heal a Heart

How do you mend a broken heart? Duke medical researchers think they have a new way, using the very scar tissue that forms after a heart attack.

Scientists at Duke University Medical Center used molecules called microRNAs to trigger scar tissue to convert itself into healthy heart muscle. They completed the conversion in a lab dish and, for the first time, in a mouse, potentially creating a way to regenerate heart tissue without the need for stem-cell transplantation.

“This is one of the exciting things about our study,” says Maria Mirotsou, assistant professor of cardiology at Duke and a senior author of the study. “We were able to achieve this tissue conversion in the heart with these microRNAs, which may be more practical for direct delivery into cells and allow for possible development of therapies without using genetic methods or transplantation of stem cells.”

The technique targets fibroblasts, cells of scar tissue that form after an attack and impair the heart’s ability to pump blood. But it may have implications beyond heart disease, says Victor Dzau, a senior author on the study and James B. Duke Professor of medicine.

“This is a significant finding with many therapeutic implications,” says Dzau, who is chancellor for health affairs at Duke. “If you can do this in the heart, you can do it in the brain, the kidneys, and other tissues. This is a whole new way of regenerating tissue.”