Bone Marrow Extract Improves Cardiac Function
Reported July 03, 2009
(Ivanhoe Newswire) -- A University of California, San Francisco (UCSF)
study found that therapy using the extract derived from bone marrow cells
effectively improves cardiac function by decreasing the formation of scar
tissue and improving cardiac pumping capacity after heart attack.
The studies were done in mice using a novel stem cell delivery method
developed by UCSF researchers to show that the extract from bone marrow
cells is as beneficial to cardiac function as are intact, whole cells. Both
the cell and cell extract therapies resulted in the presence of more blood
vessels and less cardiac cell death than no therapy. The study also showed
that heart function benefitted even though few of the injected cells
remained in the heart at one month after therapy.
"Peer-reviewed medical literature is controversial as to whether bone marrow
cells differentiate into cardiomyocytes, or cardiac muscle cells, but there
is general agreement that stem cell therapy with these cells results in some
level of functional improvement after a heart attack. The exact mechanism
for this is not yet clear. Our results confirm that whole cells are not
necessarily required in order to see the beneficial effects of bone marrow
cell therapy," Yerem Yeghiazarians, MD, study author, cardiologist and
director of UCSF's Translational Cardiac Stem Cell Development Program is
quoted as saying.
UCSF researchers are searching for new therapies to prevent heart failure
after heart attack. Heart failure occurs when cardiac muscle is damaged and
develops scar tissue. As scar replaces healthy tissue, it causes the heart
to enlarge and to lose its pumping capacity. When the pumping capacity
decreases, the heart fills with fluid, which moves to the lungs and can lead
to organ failure and death.
"Current therapies improve symptoms but do not replace scar tissue. Our hope
is to use stem cells to decrease the scar, minimize the loss of cardiac
muscle and maintain or even improve the cardiac function after a heart
attack," said Yeghiazarians.
Using a novel, closed-chest, ultrasound-guided injection technique developed
by Yeghiazarians and his colleagues, the team administered three different
groups of mice with bone marrow cells, bone marrow cell extract, or saline
(for the control group). The injections were administered at day three after
heart attack – a timeframe similar to human biology on days six-to-seven
after heart attack.
The team found at day 28 that both the bone marrow cell group and the
extract group had significantly less heart damage than the control group.
The team is continuing to evaluate bone marrow cell and extract therapies to
gain insight into the possible mechanisms of cardiac functional improvement.
"We hope our findings can help in the development of new therapies for
improving heart function after the deleterious effects of a heart attack,"
"The best acute therapy for a heart attack remains early recognition and
revascularization of the blocked artery to minimize the damage to the heart
muscle," Yeghiazarians continued. "Although the prognosis depends on
multiple factors, what we know for sure is that the sooner a heart attack
gets diagnosed and cardiologists open the blocked artery, the better the
long-term outcome. There are a number of ongoing stem cell-based clinical
trials, and depending on further research and the outcome of these studies,
we might have new therapies for the treatment of patients who suffer from a
heart attack in the not-too-distant future."
SOURCE: Journal of Molecular Therapy, July 2009