In a promising science-fiction-meets-real-world juxtaposition, researchers have discovered that the mammalian newborn heart can heal itself completely.
Working with mice researchers found that a portion of the heart removed during the first week after birth grew back wholly and correctly – as if nothing had happened.
“We found that the heart of newborn mammals can fix itself; it just forgets how as it gets older," said Dr. Hesham Sadek, assistant professor of internal medicine at the University of Texas Southwestern Medical Center. "The challenge now is to find a way to remind the adult heart how to fix itself again.”
“In contrast, the hearts of adult mammals lack the ability to regrow lost or damaged tissue, and as a result, when the heart is injured, for example after a heart attack, it gets weaker, which eventually leads to heart failure,” added Dr. Sadek.
Researchers found that within three weeks of removing 15 percent of the newborn mouse heart, the heart was able to completely grow back the lost tissue, and as a result looked and functioned just like a normal heart. The researchers believe that uninjured beating heart cells, called cardiomyocytes, are a major source of the new cells. They stop beating long enough to divide and provide the heart with fresh cardiomyocytes.
“The inability of the adult heart to regenerate following injury represents a major barrier in cardiovascular medicine,” said Dr. Eric Olson, chairman of the department of molecular biology at UT Southwestern. “This work demonstrates that cardiac regeneration is possible in the mammalian heart during a window of time after birth, but this regenerative ability is then lost. Armed with this knowledge, we can next work to discover methods to reawaken cardiac regeneration in adulthood.”
Adapted from the UT Southwestern Medical Center announcement.