In this way, the researchers were able to isolate heart progenitor cells then coax them into three different types of heart cells, called cardiomyocytes, which make up functioning heart muscle.
"Now we have our hands on a cell that doesn't have the same developmental potential as embryonic stem cells but can still make three of the major types of heart cells," Keller explained. "When we have these cells in isolation, we have a better handle on directing their pathway to cells that beat, or other [cardiac] cells. That's much more difficult when we haven't isolated the cells."
Also, when these cells were transplanted, they didn't form tumors, which often happens when a group of cells is more mixed. "In essence, we have isolated the most immature human heart cells, and we think we can control these cells much better than we would if we were starting with embryonic stem cells," Keller said.
The findings will help researchers better understand how the heart develops in humans, but therapeutic applications are still a ways off.
"It's important that we understand the basic biology," Sanberg said. "But it's still going to be a while till we see this in the clinic."
The National Institutes of Health has more on stem cells.
SOURCES: Gordon Keller, Ph.D., director, McEwen Centre for Regenerative Medicine, University Health Network, Toronto; Paul R. Sanberg, Ph.D., director, Center for Aging and Brain Repair, University of South Florida College of Medicine, Tampa; April 24, 2008, Nature
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