June 20, 2011

Targeting Stem Cells, Reducing Fat

(Ivanhoe Newswire) -- Researchers have found a way to rid the body of stem cells that are responsible for driving fat expansion.

The investigators discovered the first protein marker on the surface of adipose stromal cells (ASCs). These cells serve as progenitors of the cells that make up fat tissue.

"Our long-term goal is to identify an approach to inactivate these cells in disease," Mikhail Kolonin of University of Texas Health Science Center at Houston, was quoted as saying. "By administering a peptide with a toxin to ASCs, we could deplete these cells." In previous studies, Kolonin has used a similar approach to develop a therapy targeting the blood vessels that feed fat tissue.

In order to target ASCs, researchers had to find a unique marker on their surfaces that indentified them. They used a method that relies on billions of viral particles, each displaying a different peptide on its outer coat.

This led the scientists to a previously undescribed fragment of decorin, which is a multifunctional protein regulating cell adhesion, proliferation, and migration. The team showed that this new marker (delta-decorin) interacts with a hormone called resistin. Resistin has been known for its connection to obesity and insulin, but its receptor had remained elusive.

"The expansion of fat tissue is the foundation of obesity," Kolonin said. "For that to happen, you need progenitors to proliferate and spread around." The effects of resistin in ASCs, acting via decorin, appear to be responsible, according to the researchers.

The investigators say their research may lead to regenerative therapies as well as explaining factors in obesity. However, they say while the cells can be useful, they are also potentially dangerous, as they have been linked to cancer progression.

SOURCE: Cell Stem Cell, June, 2011