NEWS

Animal study shows human stem
cells from fat will evolve into bone

CHAPEL HILL -- In experiments showing human fat cells promise to become a new and more abundant source of adult stem cells, scientists at the Pennington Biomedical Research Center and the University of North Carolina at Chapel Hill have found that human fat stem cells can convert to bone when grown under the skin of mice.

Dr. Jeffrey Gimble of Pennington, working with Kevin Hicok, formerly of Artecel Sciences, and Dr. Lyndon Cooper, associate professor of prosthodontics at the UNC School of Dentistry, conducted the research. Pennington is a branch of the Louisiana State University System.

Their latest findings, published today (May 6) in the journal Tissue Engineering, are among the first experiments in which human fat stem cells convert to bone once implanted into a live animal. A Danish team led by Dr. Moustapha Kassem reports similar observations in the same journal issue.

Stem cells, found in all animals, are unspecialized cells that have the ability to convert to many specific cell types. Researchers had earlier determined that various signals in a growing animal cause stem cells to develop into bone, nerve, muscle, fat and other tissue types. Scientists recently duplicated the process in the laboratory.

At the annual meeting of the Orthopedic Research Society in February, Gimble and Duke University scientists described experiments demonstrating that individual stem cells in human fat, under the right biological conditions, could turn into muscle, cartilage, bone and perhaps even nerve cells in laboratory glassware.

Now, for the first time, researchers have seen those results in live animals.

"Because human fat is abundant and simple to obtain by liposuction, this finding holds the promise that patients in need of bone grafts could potentially use their own fat as a source of new bone cells," Gimble said.

To grow human bone, researchers extracted human fat through liposuction, identified and removed only the stem cells and propagated them in the laboratory. They then they attached the growing stem cells to chips of artificial bone that would serve as scaffolding.

At UNC, they implanted the chips under the skin of mice. After six weeks, the implants were recovered and studied at UNC’s core laboratory facility.

"The stem cells had converted to living human bone cells and had begun to grow on their own," Gimble said.

"These are exciting but preliminary findings," he said. "Many more experiments in animal models will be needed before this science can be used in a clinical setting."

The Pennington Biomedical Research Center, located in Baton Rouge, La., focuses on the role of nutrition and diet in human health and disease.

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Note: Gimble can be reached at (225) 763-3171, Cooper at (919) 966-4579.

Pennington Contact: Glen Duncan, (225) 763-2599
UNC News Services Contact: David Williamson, (919) 962-8596