Single stem cells repair tissue damage

STANFORD, Calif., Dec. 18 (UPI) -- U.S. researchers say they've demonstrated a single adult stem cell can self-renew in a mammal and repair damaged tissue.

Stanford University Professor Helen Blau and researchers Alessandra Sacco and Regis Doyonnas said they transplanted skeletal adult muscle stem cells into special immune-suppressed mice whose muscle satellite cells and been destroyed in a hind limb by irradiation.

The scientists also genetically engineered the transplanted stem cells to express Pax7 and luciferase proteins. As a result, every transplanted cell glowed under ultraviolet light and was easy to trace.

"To be able to detect the presence of the cells by bioluminescence was really a breakthrough," said Blau. "It taught us so much more. We could see how the cells were responding, and really monitor their dynamics."

Sacco said the researchers were thrilled with the results. "It's been known that these satellite cells are crucial for the regeneration of muscle tissue, but this is the first demonstration of self-renewal of a single cell."

The scientists said the ability to isolate and then transplant skeletal adult muscle stem cells could have a wide impact in treating not only a variety of muscle wasting diseases such as muscular dystrophy, but also severe muscle injuries or loss of function from aging and disuse.

The research was presented last week in San Francisco during the annual meeting of the American Society for Cell Biology.