Researchers have identified a protein found in the blood of both mice and humans cable of reverses the aging of the heart.

The most common form of heart failure occurs with normal systolic function (systolic meaning the rhythmic contraction of the heart) and often involves the thickening of the heart muscles in the elderly.

However, despite its prevalence, there is currently no treatment to reverse this process, a reality which led stem cell biologist Amy Wagers and cardiologist Richard Lee, both from the Harvard Stem Cell institute (HSCI), to wonder if circulating factors in young blood, such as hormones, might have an effect on aging hearts.

To test this hypothesis, the researchers employed an old but little-used technique in which they surgically linked the circulatory system of 2-year-old mice with 2-month-old mice by opening a flap of skin on the side of each one and stitching them together.

Sure enough, after four weeks of exposure to the circulation of the young mice, the heart muscles in the older mice decreased dramatically and began to resemble the hearts of the younger mice.

The reason, they discovered was a protein called GDF-11.

The potential impacts of the discovery are, Wagers and Lee believe, are tremendous.

“I have 300 patients right now, and I think about 20 who are suffering from this type of heart failure, which we sometimes call diastolic heart failure,” Lee said in an HSCI press release. “They come into the hospital, have a lot of fluid taken off, then they’ll go home. Then they come back again. It’s really frustrating because we don’t have any drugs to treat this. We need to work as hard as we can to figure out if it this discovery can be turned into a treatment for heart failure in our aging patients.”

Lee added, “This is the coolest thing I’ve ever been a part of.”

Ultimately, however, as HSCI Co-Director Doug Melton sees it, Lee’s and Wagers’ discovery doesn’t just shed light on diastolic heart failure, it will “change the way we think about aging.”