I've previously written about how muscle stem cells rev their engines in response to a distant injury, like drag cars at the starting line of a race. This priming function helps them respond more quickly to injury and trauma.
Now the same researchers, Stanford neurologist Thomas Rando, MD, PhD, and University of Southern California stem cell biologist Joseph Rodgers, PhD, have identified the specific protein responsible for alerting the stem cells and shown that it can be administered before injury to aid subsequent healing. They published their results today in Cell Reports.
From our release:
Normally, adult, tissue-specific stem cells are held in a kind of cellular deep freeze called quiescence to avoid unnecessary cell division in the absence of injury. In a 2014 paper published in Nature, Rodgers and Rando showed in laboratory mice that an injury to the muscle of one leg caused a change in the muscle stem cells of the other leg. These cells entered what the researchers called an “alert” phase of the cell cycle that is distinct from either fully resting or fully active stem cells.
Rando, who directs Stanford’s Glenn Center for the Biology of Aging, and Rodgers discovered in this new study that the "alerting" factor is a single protein that is transported in the animals' blood to prime stem cells to leap into action. Treating uninjured animals with this protein, called HGFA, enabled them to heal more quickly.
As Rodgers explained in our release:
Our research shows that by priming the body before an injury you can speed the process of tissue repair and recovery, similar to how a vaccine prepares the body to a fight infection. We believe this could be a therapeutic approach to improve recovery in situations where injuries can be anticipated, such as surgery, combat or sports.
Rando and Rodgers are also interested in learning more about the role played HGFA and its associated proteins in normal aging. “Stem cell activity diminishes with advancing age, and older people heal more slowly and less effectively than younger people," Rando told me. "Might it be possible to restore youthful healing by activating this pathway? We’d love to find out.”
Previously: Coaxing muscles to heal with less scarring could improve aging, muscular dystrophy treatments, One researcher's journey to understand the molecular basis of aging, using blood and Tick tock goes the clock - is aging the biggest illness of all?
Photo by Stephen Bowler