Cardiologists are increasingly using adult stem cells in clinical trials to repair hearts following heart attacks, but no one has understood how the therapy actually works. Now, in animal experiments, researchers at The University of Texas M. D. Anderson Cancer Center have deconstructed the process, describing how the stem cells fuse with heart muscle cells to create new cells that repopulate the ailing organ.
In a paper posted Feb 15 at Online First of the journal Circulation Research, investigators found that this fusion is only possible if two cell adhesion proteins that stick to each other like Velcro are available to attach a stem cell to a heart muscle cell. They show in cell and mice studies that if either protein is blocked, the two cells don't blend.
The investigators also discovered that these new cells, once fused, divide again in an attempt to produce enough cells to help the heart contract.
"The accepted dogma is that heart cells cannot divide, but we show that fusing stem cells onto muscle cells bestows these cells with a new and wonderful ability to divide again to repair the heart," says the study's lead author Edward T. H. Yeh, M.D., professor and chair of the Department of Cardiology at M. D. Anderson Cancer Center.
"It is marvelous that adult stem cells can help heal a heart, and by understanding the mechanisms involved, we may be able to refine and optimize the process," he says.
But there are not enough natural stem cells available in a body to mount an effective repair response to a heart attack, Yeh says, which is why researchers and clinicians are focused on boosting that response. And in the future, given what the researchers also have discovered about how stem cells can build new cells to line blood vessels, it may be possible to "choose to ether augment rebuilding of heart muscle or restoration of blood vessels, depending on what is therapeutically best for the patient."......
Whole article: "http://www.physorg.com":[ http://www.physorg.com/news90780628.html]
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