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Stem cell research: Study identifies the cells responsible for regenerating damaged muscle - and the switch that triggers the repair process

Research offers hope for patients with Muscular Dystrophy, ALS

OTTAWA, ON (June 26, 2003) - A research team from the Ottawa Hospital Research Institute (OHRI), led by Dr. Michael Rudnicki, has published a groundbreaking study that demonstrates 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 are published in the June 27 issue of the prestigious scientific journal Cell.

This landmark 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.

"Why is this important?" asks Dr. Rudnicki, who is a Professor of Medicine at the University of Ottawa. "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?' 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." However, he cautions, clinical applications are still some time away.

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, U.S. 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.

"This discovery has enormous implications for people with diseases such as muscular dystrophy, and it reflects the commitment made to stem cell research by the OHRI and the University of Ottawa," says Dr. Ron Worton, CEO of the OHRI and Scientific Director of the Stem Cell Network. "Dr. Rudnicki and his team have made a tremendous breakthrough that moves us closer to effective therapies for persons with neuromuscular disorders," said Yves Savoie, National Executive Director of Muscular Dystrophy Canada. "This groundbreaking work emphasizes the critical need to continue to expand funding for research. The path of progress blazed by Canadian researchers is outstanding and appropriate continuing funding is essential to capitalize on their results."

"Stem cell research holds out huge promise for people with ALS, and it could have an unbelievable effect on the quality of lives of many thousands of people around the world," says Helene Vassos, Interim Executive Director of the ALS Society of Canada. "Dr Rudnicki and his team at the Ottawa Hospital Research Institute have made a significant contribution. More research holds the answers."

"The work of Dr. Rudnicki and his group in the identification of the role of CD45+ cells as well as the significance of wnt protein signaling has exciting implications for future research in both the immediate and long-term. We are pleased that our funding has helped Dr. Rudnicki make this breakthrough and are certainly looking forward to following his progress," says Dr. Jill Conley, Director of International Research Resources at the Howard Hughes Medical Institute

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 that was created to capture the commercial potential of the stem cell research ongoing at the Ottawa Hospital Research Institute under the direction of founding scientists Dr. Rudnicki and Dr. Lynn Megeney.

Dr. Rudnicki is Senior Scientist and Director of the Molecular Medicine Program at the Ottawa Hospital Research Institute and future director of the Centre for Stem Cell and Gene Therapy. The 30,000-square-foot facility, which is scheduled for completion in 2004, will be one of the largest stem cell research facilities in the country. Dr. Rudnicki holds the Canada Research Chair in Molecular Genetics and is a member of the Stem Cell Network.

Patrick Seale is in his last year of Ph.D. studies at McMaster University under the supervision of Dr. Michael Rudnicki at the OHRI. Seale's studies have focused on the role of the transcription factor, Pax7 in the development and function of muscle stem cells in tissue regeneration. Patrick has accepted a postdoctoral fellowship at Harvard University where he will continue his scientific training. He currently holds a doctoral research award from the Canadian Institutes of Health Research.

Russian-born and educated Dr. Anna Polesskaya completed a post-doctoral fellowship in Dr. Rudnicki's lab in 2001-2002. She is currently a researcher in the Centre National de la Recherche Scientifique in France.


About the Ottawa Hospital Research Institute:
The OHRI is a research institute of The Ottawa Hospital and the University of Ottawa. With more than 200 scientists, 225 students and more than 400 support staff, and $42 million in external funding, the OHRI is one of the fastest growing and most respected hospital-based research institutes in Canada. Additional information about the OHRI and StemPath Inc. can be found at

About the Stem Cell Network:
The Stem Cell Network is a collaboration of 65 leading scientists, clinicians, engineers and ethicists, working together to harness the extraordinary potential of stem cells. The Network, which is based at the University of Ottawa, is one of Industry Canada's 22 Networks of Centres of Excellence, Canada's flagship science and technology program. For more information, visit

About the Canadian Institutes of Health Research:
The Canadian Institutes of Health Research is the Government of Canada's premier agency for health research. Its objective is to excel, according to internationally accepted standards of scientific excellence, in the creation of new knowledge and its translation into improved health for Canadians, more effective health services and products and a strengthened Canadian health care system. For more information visit

About the Howard Hughes Medical Institute:
The Howard Hughes Medical Institute was established in 1953 by the aviator-industrialist for whom it is named. It is a nonprofit philanthropy whose principal purpose is the direct conduct of biomedical research; its annual budget currently exceeds $600 million. Currently more than 300 HHMI investigators direct Institute research laboratories on the campuses of universities and other research organizations throughout the United States. HHMI's complementary grants program supports science education at every level in the United States and the work of selected scientists in many other countries.

For more information please contact:

Ron Vezina, The Ottawa Hospital/ Ottawa Hospital Research Institute, (613) 737-8460.
Cathy Campbell, Stem Cell Network, (613) 562-5696.
Janet Weichel, Canadian Institutes of Health Research, (613) 941-4563.

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