LOS ANGELES, APR. 10, 2001 (Zenit.org).- Human fat has been transformed into muscle, bone and cartilage for the first time, revolutionizing the prospects for regrowing diseased or damaged organs and tissues — and further undercutting the widely held belief that unborn babies are the only significant source of stem cells.
American scientists have discovered that stem cells harvested from fat, which can be extracted in a normal liposuction procedure, can easily be reprogrammed in the lab to grow a variety of tissue types.
The work is the latest in a recent series of discoveries suggesting that many parts of the adult body contain stem cells, which can mature into many kinds of tissues.
The newest findings have convinced researchers that fat reserves will provide a plentiful, easy to extract and ethically acceptable source of stem cells which have the potential to develop into many specialized cell types that can replace damaged, dead or missing tissue, The Times of London said.
Marc H. Hedrick, of the University of California at Los Angeles School of Medicine, who led the new study, said its results would revolutionize so-called tissue engineering.
«Until now, we had not identified a good source of stem cells, which can be thought of as the building blocks of tissue engineering,» he said. «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,» he said. «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.»
Adam J. Katz, of the University of Pittsburgh School of Medicine, another member of the research team, said the potential of fat could make the much-criticized use of fetal stem cells obsolete.
In the study, details of which are published today in the journal Tissue Engineering, researchers extracted fat from volunteers using liposuction — cosmetic surgery used to remove unwanted fat. They then isolated stem cells from the fat tissue and used growth factors and proteins to prompt them to develop into three distinct types of cell: muscle, cartilage and bone.
The team has been able to grow only cell cultures of the particular tissue types but believes it will be possible to induce these cells to grow along a three-dimensional lattice to «mould» replacement tissues. That could then be transplanted into, for example, a patient who had lost the cartilage in the knee through a football injury.
The transplanted tissue grown from fat would be genetically identical to the patient, preventing the possibility that it might be rejected by the immune system.
In the longer term, it may be possible to grow fat stem cells into more complicated tissue, such as liver or heart cells, to grow complete organs that might be used to replace damaged originals.
«It´s highly provocative work and they´re probably right,» Eric Olson, chairman of molecular biology at the University of Texas Southwestern Medical Center in Dallas, told the Washington Post.
At least one company is betting on fat´s potential as a source of new tissues, the Post reported. Jeffrey Gimble of Artecel Sciences in Durham, North Carolina, said the company has also derived various tissues from human fat, though it has not published its work.
