Serious muscle injuries, such as the permanent debilitating
scarring that results from heart attack, could be repaired
by adult stem cells in blood, according to a University of
British Columbia researcher.
Fabio Rossi, Canada Research Chair in Regenerative Medicine,
has shown that adult stem cells found in bone marrow — blood-forming
(hematopoietic) cells — can also form muscle cells.
Rossi extracted individual blood-forming stem cells from
bone marrow. He introduced the single cells into blood and
found their “offspring” not only produced blood
but also helped to repair damaged muscle tissue.
Rossi’s discovery, in collaboration with Stanford University
scientists, will help scientists move closer to developing
new treatments for muscle injury. For example, heart attacks
create permanent scarring because the heart contains no adult
stem cells — specialized cells that can renew themselves
to repair specific tissues. Rossi’s findings suggest
that the blood-forming stem cells could be used to renew cardiac
muscle tissue after a heart attack.
The findings, recently published in Nature Medicine, suggest
a new avenue of treatment possibilities for muscle damage
“Now we can focus on these particular stem cells and
accelerate our efforts to make them a useful therapy,”
says Rossi, an assistant professor of Medical Genetics and
a member of UBC’s Biomedical Research Centre. “Right
now, the cells have significant potential but limited therapeutic
Scientists have been aware that cells found in bone marrow
have some positive effect on damaged muscle tissue, however,
they did not know which cell was responsible or the mechanics
of the process.
Also, adult stem cells are usually capable of renewing only
the tissue from which they originate and, until now, their
potential to generate other types of cells was questioned.
Adult stem cells hold promise as an alternative to embryonic
stem cells that are able to grow all types of human tissue
but are the subject of considerable ethical debate. Adult
stem cells are difficult to grow in the lab and clinically
significant amounts are hard to obtain.
Rossi estimates that it will be at least 10 years before
adult stem cells can replace embryonic stem cells as an effective
This study was done with the support of Canadian Institutes
of Health Research and the Stem Cell Network, one of Canada’s
Networks of Centres of Excellence.
NB. Editors: A brief biography and picture of the researcher
are available electronically, as well as colour images of
muscle cells repaired by hematopoietic stem cells.