American scientists have created a "switch" that allows mutations or light signals to be turned on in muscle stem cells to monitor muscle regeneration in a living mammal.
The research team, including 2007 Nobel Prize winner Mario R. Capecchi, say that their breakthrough may lead to a genetic switch, or drugs, that allows people to grow new muscle cells to replace those that are damaged, worn out, or non-functional.
The researchers also say that their work provides a new tool for studying muscle cancers, which are very difficult to treat.
"We hope that the genetically-engineered mouse models we developed will help scientists and clinicians better understand how to make muscle stem cells regenerate muscle tissue," said Dr. Charles Keller, assistant professor at the University of Texas Health Science Center and a senior researcher involved in the work.
"For our own work on childhood muscle cancers, we also hope to understand how tumours start and progress, and to develop therapies that are less toxic than chemotherapy," he added.
The researchers have revealed that they made this advance by breeding mice with a specific gene called "Cre", which, when activated, can trigger mutations in muscle stem cells.
They point out that this Cre trigger is restricted to muscle stem cells and requires a special drug for it to be activated.
During the study, the researchers used fluorescent techniques that allowed them to visualize stem cells and their derivatives, in order to pinpoint exactly where muscle tissue was being made.
The team say that, in one part of the study, they were also able to activate tumour-causing mutations in muscle stem cells, providing valuable insights into the origins of muscle tumours, which have been previously elusive.
A report on the groundbreaking work has been published online in The FASEB Journal.
"This is basic science at its best. This study in mice has not only shown us how stem cells turn into muscle in the living body, but brought us closer to the day when we can use stem cells to repair wounded flesh or a maimed physique," said Dr. Gerald Weissmann, Editor-in-Chief of the journal.