UW researchers find positive results repairing monkey hearts

Scientists at the University of Washington say they have determined stem cell therapy can regenerate a heart muscle in primates.

UW researchers were working to repair hearts weakened by myocardial infarctions, a common type of heart attack that blocks every major artery and deprives the heart of oxygen, when they made the discovery.

“We’ve been trying for a while to figure out a way to try and coax these stem cells, called human embryonic stem cells, in heart muscle cells and over the years had applied them in a variety of sort of models of myocardial infarctions,” explains UW Associate Professor Michael LaFlamme.

According to researchers, survivors of a severe heart episodes often continue their lives in poor health because their hearts are no longer working properly.

Hoping to restore hearts to their regular function, researchers ran tests using heart cells created from human embryonic stem cells.

“Each injured heart in the study received 1 billion cardiomyocytes (cardiac muscle cells) and they would form new muscles in the heart replacing the scar that you otherwise have after a heart attack,” says LaFlamme.

In this research, the human muscles were growing in a monkey heart.

“Ultimately, we’re interested in determining whether these cells will be safe and useful in human beings that have suffered a heart attack and could go into heart failure, or are already in heart failure in some cases,” says LaFlamme.

Researchers used a pig-tailed macaque for their study in order to see if they could create enough cardiac muscle cells to re-muscularize damaged hearts in a large animal whose heart size and physiology are human-like.

According to LaFlamme, the results appear to be successful. “We showed for the first time that those cells in those hearts were not only able to graft and live there, but they were able to hook up with the host muscle and fire with each beat.”