A study at the Stanford University School of Medicine has revealed that a single protein is key in priming stem cells to respond to injury. Experiments in mice showed that the primer protein helped in quicker recovery from muscle injury. In fact, the skin also healed more rapidly and hair grew back quicker in the mice treated with the protein. Scientists hope to apply these findings to help people recovering from surgery and perhaps to restore youth to aging stem cells.
Wound Healing Following Trauma and Aging
Professor of Neurology and Neurological Sciences, Thomas Rando, M.D., Ph.D., explains that stem cells in the muscles and bone marrow respond to injury in distant organs by entering a state of alertness. When trying to gain a better understanding of wound healing following trauma and in aging individuals, the team discovered that a single protein is responsible for galvanizing the stem cells to perform better and faster.
Stanford Study Finds Key Protein in Injury Repair
Researchers at the Glenn Center for the Biology of Aging, led by senior study author Rando and Joseph Rodgers, Ph.D., of the University of Southern California, have published their findings in the journal Cell Reports.
The team believes the findings could lead to the development of a novel therapeutic approach for anticipated injuries, such as following surgery or for people engaged in contact sports. By priming the body with the protein in advance, the person will be better prepared to repair the anticipated injury. This mechanism is similar to vaccinating a person to help fight infection.
Stem Cells and Tissue Repair
In healthy adults, tissue-specific stem cells do not undergo unnecessary cell division and are maintained in a quiescent state. However, previous research has shown that injury to one side of the body puts stem cells on the other side of the body also into an alert state. Stem cells in the alert state are different from both quiescent and active stem cells.
The findings led the researchers to postulate that some factor is released by the damaged tissue that travels to distant areas of the body to galvanize quiescent stem cells into a state of alertness. The Stanford study identified a protein known as hepatocyte growth factor (HGF) that is critical in stimulating the production of proteins that make stem cells alert.
Stem Cells and Faster Wound Healing
Experiments at Stanford involved the injection of blood serum from injured mice into healthy mice. When tested a couple of days later, the uninjured mice who had received the serum had stem cells in the alert state that were dividing more rapidly. It was obvious that some factor in the blood of injured mice was alerting the stem cells.
A protein called HGFA was identified as the factor that activates HGF. Further, the scientists tried blocking HGFA with an antibody and found that the injury recovery benefit was no longer present. Moreover, mice who received an intravenous dose of HGFA two days before the injury was induced recovered more rapidly than untreated mice. Both muscle and skin responses were dramatically better.
In addition to injury repair, the findings are interesting in that they could pinpoint ways to alert stem cells in aging individuals. With advancing age, there is a decrease in stem cell activity, which is why older people are slower to heal from injuries.