New insight into the
heart's ability to repair itself could help scientists develop ways to improve
recovery after a heart attack, a new study of mice suggests.
Researchers found that a signalling
pathway called the Hippo pathway normally blocks heart repair in adult mice.
When certain signals were removed, the animals' hearts were able to regenerate
after being damaged.
This was because
specialised heart cells called "cardiomyocytes" were able to multiply
much better after the signals were removed, an ability that is normally lost in
damaged hearts, according to the researchers from the Baylor College of
Medicine and the Texas Heart Institute.
"The heart is very
poor at repairing itself after various types of injury including the most
common injury, the myocardial infarct [heart attack]," team leader James
Martin said in a news release from The Company of Biologists.
"We were very excited
to see full return of cardiac function in the Hippo-mutant hearts after injury.
It was the culmination of a lot of hard work and also a little good luck,"
The study was recently
published in the journal Development.
Ability lost during adulthood
Previous research has shown
that hearts can regenerate in embryos during their development, and also in
newborn mice. But this ability is lost during adulthood. Some fish and
amphibians can repair their hearts as adults, but it's believed that humans
lost this ability during the course of evolution.
This new finding suggests
that it may be possible to reactivate the human heart's ability to repair
"The implications for
treating heart disease are great. With recent advances, it is now clear that
the heart muscle can be coaxed to make new muscle cells," Martin said.
Scientists note, however,
that research with animals often fails to provide similar results in humans.
The US National Heart,
Lung, and Blood Institute has more about heart attack.