The cover illustration shows how researchers are able to “see” stem cells right through a subject’s chest wall, thanks to molecular and cellular imaging techniques that make the cells “glow like fireflies,” Ebert said.

Stem cells can create any type of tissue in the body and thus they hold great promise for regenerating heart muscle in patients with cardiovascular disease as well as treatments for other conditions, such as diabetes and Parkinson’s disease. While research on the cardiac applications for stem cells has intensified in recent years and has seen much progress, researchers still lack a great deal of information on how stem cells actually behave over time. “The question is how can we follow these guys in the lab and find out where they’re going?” Ebert said.

As part of their research, the College of Medicine team engineered the cells with the same enzyme that makes fireflies glow in the dark. As the cells develop into healthy heart muscle, they grow brighter and can be seen using a dark box and special camera. “The light comes from the heart itself,” Ebert said.

An advantage of bioluminescent imaging is that it is non-invasive, meaning the subject’s chest cavity doesn’t have to be opened to determine how the stem cells have performed. “I think the journal editors were excited about the work because we developed a novel tool for following the transplanted stem cells,” Ebert said. “Now we can peer inside the chest wall with greater precision. It’s very exciting.”

The next step, he said, is using the stem cells in disease models to see how they actually can heal the damaged heart and what conditions are most suitable for the stems cells to thrive and repair the heart.