Discovery Of First Plentiful
Source Of Stem Cells Could Make Fetal Tissue Use Unnecessary
http://www.sciencedaily.com/releases/2001/04/010410084918.htm
Source:
University Of California, Los Angeles (http://www.ucla.edu/)
Ushering in a new
era of tissue engineering research, scientists at UCLA and the University
of Pittsburgh have isolated fat as the first practical, plentiful and economic
source of stem cells used to grow a variety of human tissues in the laboratory.
Previously, stem
cells for tissue engineering research had been harvested from bone marrow,
brain and fetal tissue, limited sources that pose a variety of logistical
and ethical challenges. The availability of the plentiful source of stem
cells will accelerate development of new procedures for repairing and replacing
damaged, dead or missing tissue in people.
"Until now, we had
not identified a good source of stem cells, which can be thought of as
the building blocks of tissue engineering," said Dr. Marc Hedrick of the
UCLA School of Medicine's Division of Plastic and Reconstructive Surgery,
the research team's primary investigator. "Fat is perhaps the ideal source.
There's plenty of it. It's easy and inexpensive to obtain. It even has
a secondary cosmetic benefit.
"Our findings show
that fat is not the tissue we once thought. Just as the Industrial Revolution
transformed oil from trash to treasure, our research shows that unwanted
human fat actually is a vigorous tissue with a tremendous amount of potential
for good."
The researchers said
the discovery could render the controversial use of fetal tissue obsolete.
"We don't yet know
the limits for stem cells found in fat. So far, we have seen promising
results with all of the tissue types we have examined," said Dr. Adam J.
Katz, a member of the research team from the Division of Plastic and Reconstructive
Surgery at the University of Pittsburgh School of Medicine. "This discovery
potentially could obviate the need for using fetal tissue."
Immature and unspecified,
stem cells are key contributors to the body's ability to renew and repair
its own tissues. They are unique in their ability to mature into two or
more different types of specific cells, depending on their environment.
Researchers grow different tissues in the laboratory by manipulating stem
cell environments.
"Stem cells are like
little kids who, when they grow up, can enter a variety of professions,"
Hedrick said. "A child might become a fireman, a doctor or a plumber, depending
on the influences in their life - or environment. In the same way, these
stem cells can become many tissues by making certain changes in their environment."
Stem cells already
are used as a treatment for leukemia and some joint repairs. With fat as
a plentiful source of stem cells, researchers may be able to accelerate
the pace of overcoming obstacles that prevent broader applications. These
challenges include finding ways to supply blood to larger tissues, control
growth and maturation, and eliminate scarring.
"We're just figuring
out the best ways to apply this technology, but expect the first practical
uses for laboratory-grown tissues to enter the medical marketplace within
the next five years or so," Hedrick said. "We hope one day to be able to
remove diseased tissue or organs, harvest stem cells and replace the lost
tissues on the same day during the same operation. There is potential for
regenerating a lot of different tissues, perhaps some day solid organs,
glands, nerves or brain tissue."
The Wunderman Family
Foundation provided primary funding for the research team. Other contributors
include the Pittsburgh Tissue Engineering Initiative, the Plastic Surgery
Education Foundation and American Society for Aesthetic Plastic Surgery.
Patricia A. Zuk and
Dr. Min Zhu of the UCLA School of Medicine co-authored the paper. Other
researchers involved in the study were Dr. Hiroshi Mizuno, Jerry Huang,
Dr. Prosper Benhaim and Dr. H. Peter Lorenz, all of UCLA; and Dr. J. William
Futrell of the University of Pittsburgh School of Medicine.
Related Web Sites:
* UCLA School of
Medicine -- http://www.medsch.ucla.edu/
* University of Pittsburgh
School of Medicine -- http://www.dean-med.pitt.edu/
Date:
Posted 4/10/2001
The research team,
which details the discovery in the April edition of the peer-reviewed journal
Tissue Engineering, is the first to grow human tissue - bone, muscle, cartilage
and fat - using stem cells harvested from fat. The team obtained the fat
using liposuction.