Now, regenerating heart tissue in humans with stem cells a possibility

A new study, where heart tissues were regenerated in salamanders with the help of stem cells, has raised hopes for better therapies for people with damaged hearts.

We have known for hundreds of years that newts and other types of salamanders regenerate limbs. If you cut off a leg or tail, it will grow back within a few weeks.

Stanley Sessions, a researcher at Hartwich College in Oneonta, N.Y., wondered if this external phenomenon also took place internally. To find out, he surgically removed a piece of heart in more than two dozen newts.

"To our surprise, if you surgically remove part of the heart, the creature will regenerate a new heart within just six weeks or so," Sessions said.

In fact, you can remove up to half of the heart, and it will still regenerate completely, Sessions asserted.

Before the research team dove deeper into this finding, Sessions and his three undergraduate students, Grace Mele, Jessica Rodriquez and Kayla Murphy, had to determine how a salamander could even live with a partial heart.

It turns out that a clot forms at the surgical site, acting much like the cork in a wine bottle, to prevent the amphibian from bleeding to death.

The cork is in part made of stem cells that have unlimited potential for growth and can develop into cells with a specialized fate or function.

Embryonic stem cells, for example, can give rise to all of the cells in the body and, thus, have promising potential for therapeutics.

As it turns out, stem cells play an important role in regeneration in newts. Sessions explained that at least some of the stem cells for heart regeneration come from the blood, including the clot.

This finding could have exciting implications for therapies in humans with heart damage.

By finding the genes responsible for regeneration in the newt, researchers may be able to identify pathways that are similar in newts and people and could be used to induce regeneration in the human heart.