Stem Cells Create Mighty Mice

Stem cell injections boosted the leg muscles of mice and warded off the typical loss of muscle mass that comes with aging.

The discovery could be useful in treating humans with degenerative diseases such as muscular dystrophy, as well as help everyday people prevent at least some of the ravages of time, the researchers said.

Scientists removed stem cells from the legs of three-month-old healthy mice and injected them into the legs of mice that had temporary leg muscle injuries, induced by barium chloride injections, the study said.

The technique repaired the injuries within days and made the treated muscle double in size.

Two years later, they found that the "procedure permanently changed the transplanted cells, making them resistant to the aging process in the muscle," said study author Bradley Olwin of the University of Colorado.

"The transplanted material seemed to kick the stem cells to a high gear for self-renewal, essentially taking over the production of muscle cells," he said.

However, the team found no such effect when the transplant of cells was made into healthy mouse muscles.

"We found that the transplanted stem cells are permanently altered and reduce the aging of the transplanted muscle, maintaining strength and mass," said Olwin.

"This was a very exciting and unexpected result," he said of the findings, published in the journal Science Translational Medicine.

"In this study, the hallmarks we see with the aging of muscles just weren't occurring," said Olwin.

"With further research we may one day be able to greatly resist the loss of muscle mass, size and strength in humans that accompanies aging, as well as chronic degenerative diseases like muscular dystrophy."