Molecule could limit development of obesity

A new discovery from OMRF could help doctors limit obesity in patients.

“Obesity is a growing concern across the country, but especially in Oklahoma, where more than 33 percent of the population is considered morbidly obese,” said OMRF researcher Jana Barlic-Dicen, Ph.D. “It’s a risk factor for a number of serious conditions, including cardiovascular disease, diabetes, osteoarthritis, cancer and infertility.”

Efforts to understand obesity led Barlic-Dicen and scientist Longbiao Yao, M.D., to study the role of a surface molecule, the receptor called CXCR4, in body weight gain and fat tissue inflammation.

“The uncontrolled expansion of fat tissue that leads to obesity is supported by a vicious cycle,” she said. “When we consume more food than we need to, we store the extra energy in a form of fat. If we chronically overeat, fat cells, which continue to store extra caloric intake, send out alarm signals in the form of proteins known as chemokines, which recruit white blood cells into growing fat tissue.”

The white blood cells cause inflammation that encourages the tissue to grow even more. One of the alarm signals produced by the expanding fat tissue is able to activate the receptor CXCR4.

CXCR4, which is nearly identical in mouse and human, is present on fat cells in both organisms, but its role in this tissue was unknown. The researchers fed mice that lacked CXCR4 and normal mice a high-fat diet, similar in composition to fast food.

Mice missing CXCR4 on their fat cells gained more weight and gained the weight a lot faster than control mice which maintained this receptor on fat cells.

“We now know that the main role of CXCR4 in fat tissue is to set limits to obesity,“ she said. “It’s possible that if we stimulate CXCR4, we may be able to help patients to burn more energy and therefore reduce obesity.”

The work was published in FASEB Journal.

Other OMRF scientists contributing to the research were Luke Szweda, Ph.D., Timothy Griffin, Ph.D., Oana Herlea-Pana, Ph.D., and Janet Baker.

The research was funded by grant No. 8 P20 GM103441-08 from the National Institute of General Medical Sciences, a part of the National Institutes of Health, No. HR10-099 from the Oklahoma Center for the Advancement of Science & Technology and No. 4340-03-06 and 4340-04-120 from the Oklahoma Center for Adult Stem Cell Research.