Master Stem Cell for Human Heart Identified

July 2 -- WEDNESDAY, July 1 (HealthDay News) -- For the first time, researchers have identified a single "master" stem cell in humans that is capable of differentiating into all three major cell types that make up the human heart.

"This is a very simple but very important and fundamental finding, and that is understanding how the human heart is built, how it is made, what are the progenitor cells which give rise to the human heart," said Dr. Kenneth Chien, head of the Harvard Stem Cell Institute's cardiovascular disease program and senior author of a paper in the July 2 issue of Nature.

"This means we are in a new era where we can envision entirely human-based models of cardiovascular disease," added Chien, who is also director of the Massachusetts General Hospital Cardiovascular Research Center.

Because this is a first, there could be enormous implications for further research into the human heart and, eventually, into repair and regeneration of the organ in people who have had heart attacks or have heart failure or congenital heart defects.

Understanding the mechanisms of the human heart might also help in the development of drugs with fewer heart-related side effects as well as allow better monitoring of drugs already available. Chien, who spoke to journalists in teleconference Wednesday, pointed out that many widely used and valuable drugs, such as Herceptin (for cancer) and Avandia (for diabetes), have heart-related side effects. The painkiller Vioxx was withdrawn from the market after widely publicized side effects were noted.

The breakthrough research "offers more understanding of how to model the development of the human heart, and, by understanding that, we might be able to understand what goes wrong," said Paul Sanberg, a stem cell expert and director of the University of South Florida Center for Aging and Brain Repair in Tampa. "One day there may even be the potential for stem cell therapy."

Although the genesis of the heart has been studied extensively in organisms including zebra fish, flies and mice, much less is known about what happens in the human heart, Chien said.