Next, using the same fluorescent "tags," Orkin and Wu isolated the same cardiac progenitor cells directly from live mice early in embryonic development.
"There have been a number of publications about stem-like cells in the heart, but these are the first studies to identify such cells during embryonic development, and to show that they give rise to different cell types," says Orkin, who is the David G. Nathan Professor of Pediatrics at Harvard Medical School and also chairs the department of pediatric oncology at Dana-Farber Cancer Institute. He and Wu are also members of the Harvard Stem Cell Institute.
"Previously, it had been thought that each cell type in the heart had a different origin. Now, it's pretty clear that some have common origins," Orkin adds. "This changes the notion of how the heart develops. Instead of multiple different cell types migrating and coming together to form the heart, the heart comes from stem cells that give rise to multiple cell types in the same local environment ?a simpler way of building the organ. And because these cells can make multiple cell types, they could be more useful in repairing the heart than any single kind of cell."
Orkin cautions that there are many steps before cardiac progenitor cells could be used to repair a human heart. The studies were done in mice, and it's still unknown what factors make embryonic stem cells differentiate into cardiac progenitors, or what factors make cardiac progenitors differentiate into more specialized heart cells. But ultimately, cardiac surgeons at Children's hope to be able to use cardiac stem cells to repair congenital heart defects such as defective heart valves, missing or undeveloped arteries, or underdeveloped heart chambers.
"If you understand the process of how
Source:Children's Hospital Boston