Human heart master cells identified

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Researchers have identified the early master cells that make up the human heart and said on Wednesday they could someday be used to make patches to fix damaged hearts.

The discovery, published in the journal Nature, also sheds surprising light on how human hearts develop in the womb, and how congenital heart disease develops.

"This cell that we describe is probably not going to be used directly as cell-based therapy because it has the possibility of going into too many different cell types," said Kenneth Chien of the Harvard Stem Cell Institute and Massachusetts General Hospital.

But Chien said his team is now looking for intermediate cells that are on their way to becoming beating heart muscle, the cells that line the arteries, and other heart cell types.

More immediately, it helps in understand what causes heart disease, Chien told reporters in a telephone briefing.

"The study provides a new way of understanding heart disease as it appears in children and in adults," Chien said.

Chien's team worked entirely with human cells and found the human heart develops differently from hearts in mice -- a surprising finding.

"The human heart at birth is more than a thousand times bigger than the adult mouse heart, yet the size of the initial embryos are close in size. Humans are just a heck of a lot bigger than mice, and every organ is bigger. How is that achieved?" Chien asked.