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Stem Cell News
Muscle Repair Potential Discovered in Human Source
of Adult Stem Cells
Science Daily, September 5, 2007
With the potential to treat muscle injuries and
diseases such as muscular dystrophy and heart attack,
scientists at Children's Hospital of Pittsburgh of
UPMC have discovered a unique population of adult stem
cells derived from human muscle that can be used for
this purpose for the first time.
Led by Johnny Huard, PhD, and Bruno Péault, PhD, a
study at the Children's Stem Cell Research Center has
isolated and characterized stem cells taken from blood
vessels (known as myoendothelial cells). The cells
were determined to be capable of proliferating into
cartilage, bone and muscle tissue. The study was
conducted using human muscle tissue and the cells were
easily isolated using cell-sorting techniques.
According to Drs. Huard and Péault, the cells are
ideally suited as a potential therapy for muscle
injuries and diseases because of these
characteristics.
"Finding this population of stem cells in a
human source represents a major breakthrough for us
because it brings us much closer to a clinical
application of this therapy," said Dr. Huard, the
Henry J. Mankin Professor and vice chair for Research
in the Department of Orthopaedic Surgery at the
University of Pittsburgh School of Medicine.
"To make this available as a therapy, we would
take a muscle biopsy from a patient with a muscle
injury or disease, remove the myoendothelial cells and
treat the cells in the lab. The stem cells would then
be re-injected into the patient to repair the muscle
damage. Because this is an autologous transplant,
meaning from the patient to himself, there is not the
risk of rejection you would have if you took the stem
cells from another source."
Dr. Huard's laboratory team first identified a
unique population of muscle-derived stem cells with
the ability to repair muscle 8 years ago while working
with dystrophic mice in the process of searching for a
cure for Duchenne muscular dystrophy (DMD).
The importance of determining the origin of these
muscle-derived stem cells was recognized by Dr. Péault,
who is a professor in the Department of Pediatrics,
Cell Biology and Physiology at the University of
Pittsburgh School of Medicine. It was discovered that
these myoendothelial cells are located adjacent to the
walls of blood vessels during human muscle biopsies
using techniques of confocal microscopy and cell
sorting by flow cytometry among others.
Opposed to other sources of stem cells known as
satellite and endothelial cells, myoendothelial cells
taken from the blood vessels are much more efficient
at forming muscle according to the study.
A concern with other stem cell therapies,
myoendothelial cells also showed no propensity to form
tumors. And compared with 9 and 5 muscle fibers for
endothelial and satellite cells, respectively; a
thousand myoendothelial cells transplanted into the
injured skeletal muscle of immunodeficient mice
produced, on average, 89 muscle fibers.
Numerous therapeutic uses for the population of
stem cells the SCRC team identified are being
developed and researched by Drs. Huard, Péault and
colleagues in Children's Stem Cell Research Center (SCRC).
Affecting an estimated 3,500 boys, DMD, which is a
genetic disease, could be one of hte most promising
application targets of the treatment. Patients with
DMD lack dystrophin, a protein that gives muscle cells
structure.
In order to treat a variety of orthopedic and
musculoskeletal diseases and injuries, Dr. Huard is an
internationally recognized cell biologist conducting
laboratory research into the therapeutic use of stem
cells. To repair damaged muscle and regenerate bone
and cartilage, Dr. Huard is developing cutting-edge
therapies in the lab. The repair of sports-related
bone, cartilage and muscle injuries to the repair of
heart muscle damaged by heart attack could be among
the range of applications the therapies could be used
to treat.
Dr. Péault's laboratory has also deciphered the
ultimate origin during embryonic life while becoming
internationally recognized principally for their work
on the prospective identification and characterization
of human hematopoietic (blood) stem cells. Elusive
populations of multipotent stem cells that persist in
adult tissues, including dispensable ones like fat,
are also being investigated by the team aside from
blood development. Patients suffering from multiple
organs damaged by acquired diseases, genetic diseases,
aging, or trauma should be greatly aided by
regenerative therapies using such cells.
The journal Nature Biotechnology has published the
results of the study in their September issue.
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