Stem Cells to Fight Muscle Aging

Ivanhoe Newswire
Tuesday, June 17, 2008; 4:15 AM

(Ivanhoe Newswire) -- A recent study on mice shows stem cells may be able to stop the effects of aging on muscles, which could prevent conditions like muscle atrophy and Parkinson's disease.

Adult stem cells in muscles have a receptor called Notch that, when activated, tells them to grow and divide. As the body ages, this receptor's activity is inhibited by the activity of another receptor for the protein TGF-beta. These two pathways -- one an aging pathway, one a youthful pathway -- compete for control of stem cell growth and division.
"As we age, our stem cells are prevented, through chemical signals, from doing their jobs," lead researcher Irina Conboy, Ph.D., an assistant professor of bioengineering and an investigator at the Berkeley Stem Cell Center and the California Institute for Quantitative Biosciences, was quoted as saying.
In a study at the University of California, Berkeley, researchers disabled the aging pathway on a group of old mice and compared their muscle healing process with that of young mice and a control group. They found muscles in the "treated" old mice healed similarly to the young mice, and their levels of cellular regeneration were three to four times greater than those of the control group.

"When we are young, there is an optimal balance between Notch and TGF-beta," Dr. Conboy said. "We need to find out what the levels of these chemicals are in the young so we can calibrate the system when we're older. If we can do that, we could rejuvenate tissue repair for a very long time."

SOURCE: Nature; published online June 15, 2008

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