Bethesda, MD—In a genetic engineering breakthrough that could
help everyone from bed-ridden patients to elite athletes, a team of
American researchers—including 2007 Nobel Prize winner Mario
R. Capecchi—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. For humans, this
work could lead to a genetic switch, or drug, that allows people to
grow new muscle cells to replace those that are damaged, worn out, or
not working for other reasons (e.g., muscular dystrophy). In addition,
this same discovery also gives researchers a new tool for the study of
difficult-to-treat muscle cancers. The full report containing details
of this advance is available online in
The FASEB Journal (
http://www.fasebj.org).
“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
Charles Keller, M.D., 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 tumors start and progress, and to develop therapies
that are less toxic than chemotherapy.”
The scientists made their discovery by breeding special mice with a
specific gene, called “Cre,” which, when activated,
can trigger mutations in muscle stem cells. This Cre trigger is
restricted to muscle stem cells and requires a special drug for it to
be activated. In one part of the study, using fluorescent techniques,
the researchers were able to visualize stem cells and their derivatives
in order to pinpoint exactly where muscle tissue was being made. In
another part of the study, the scientists were able to activate
tumor-causing mutations in muscle stem cells, providing valuable
insights into the origins of muscle tumors, which have been previously
elusive.
“This is basic science at its best,” said Gerald
Weissmann, M.D, Editor-in-Chief of
The
FASEB Journal. “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.”
Subscribe to
The FASEB
Journal’s mailing list to receive monthly
article summaries right in your inbox by signing up at
http://www.faseb.org/fasebjournalreaders.htm.
The FASEB Journal (
http://www.fasebj.org)
is published by the Federation of the American Societies for
Experimental Biology (FASEB) and is the most biology cited journal worldwide
according to the Institute for Scientific Information. FASEB
comprises 22 nonprofit societies with more than 80,000 members, making
it the largest coalition of biomedical research associations in the
United States. FASEB advances biological science through
collaborative advocacy for research policies that promote scientific
progress and education and lead to improvements in human health.
###
Article Details:
The lead author of this study, Koichi Nishijo, M.D., Ph.D., is an
orthopedic surgeon whose interests are both traumatic muscle injury and
muscle cancer resections. Koichi Nishijo, Tohru Hosoyama, Christopher
R. R. Bjornson, Beverly S. Schaffer, Suresh I. Prajapati, Ali N.
Bahadur, Mark S. Hansen, Mary C. Blandford, Amanda T. McCleish, Brian
P. Rubin, Jonathan A. Epstein, Thomas A. Rando, Mario R. Capecchi, and
Charles Keller. Biomarker system for studying muscle, stem cells, and
cancer in vivo. FASEB J. doi:10.1096/fj.08-128116.
http://www.fasebj.org/cgi/content/abstract/fj.08-128116v1