Study identifies the cells responsible for regenerating damaged muscle and the switch that triggers the repair process

Ottawa, ON July 5, 2003 A research team from the Ottawa Health Research Institute, led by Dr Michael Rudnicki, has published a study demonstrating how a novel population of adult stem cells resident in muscle tissue plays an important role in muscle regeneration.

For the first time, the research also identifies details of the molecular signals that direct these adult stem cells to form new muscle, offering hope for millions of people with neuromuscular disorders.

The Rudnicki team’s findings were published in the June 27 issue of the prestigious scientific journal Cell.

The research shows that a class of adult muscle stem cells, called CD45+ cells, play a natural role in regeneration when they receive signals in the form of a secreted protein known as Wnt. Wnt proteins are secreted in response to tissue damage and act to trigger the stem cells to divide and then develop into highly specialized muscle cells.

“A central question in the application of stem cells to repair damage has been ‘what are the switches that trigger the stem cells to make new tissue of a specific type?’," says Dr Rudnicki, who is a professor of medicine at the University of Ottawa. "Now that this question has been answered for muscle tissue, we can exploit this knowledge to potentially benefit people with neuromuscular diseases such as muscular dystrophy or diseases that involve muscle wasting such as multiple sclerosis, ALS, and cancer.”

A focus of future research will be to develop drugs that target the Wnt signaling pathway as new treatments for neuromuscular diseases and muscle injury.

Dr Rudnicki’s research is funded by the Canadian Institutes of Health Research, US National Institutes of Health, Howard Hughes Medical Institute, the Muscular Dystrophy Association, the Canada Research Chair Program and the Stem Cell Network, a Network of Centres of Excellence based at the University of Ottawa.

Patents covering therapeutic and diagnostic aspects of the work reported in Dr Rudnicki’s paper have been filed by StemPath. StemPath is a new company created to capture the commercial potential of the stem cell research ongoing at the Ottawa Health Research Institute under the direction of founding scientists Dr Rudnicki and Dr Lynn Megeney.