Scientists at Brown University in Providence, Rhode Island engineered male and female mice to produce the IKKbeta enzyme in their fat. The altered mice can eat more but gain less weight. The animals exhibit the ability to burn sugar and fat more effectively.

"Turning on this molecule has a very dramatic impact on lipid metabolism," said Haiyan Xu in a paper describing the research in the January 2012 issue of Endocrinology. Xu is an assistant professor of medicine (research) in the Warren Alpert Medical School of Brown University and a researcher at Rhode Island Hospital's Hallett Center for Diabetes and Endocrinology.

The research cites that obesity and inflammation are the main contributors for insulin resistance with obesity being the worse one. The study changed the sequence of events leading to insulin resistance from obesity leading to inflammation. The test had two groups of mice who are fed high-fat diet.

The enzyme IKKbeta induces inflammation in the fatty tissues of the test mice before they become obese. The transgenically altered mice who were given the same diet as the unaltered weight less than 38 grams while the control group weight around 45 grams.

The mice that received the treatment experienced slower weight gain despite eating more food because of their increased metabolism. The mice exhibited increased activity proving that the sugar in the body were metabolized.

The mechanism of IKKbeta on how it helps metabolism is still not clear but the researchers measured increased expression of genes associated with both fatty acid oxidation and mitochondria production, the organism in the cell responsible for energy production.

"Lower body weight is always a beneficial thing for influencing insulin sensitivity," Dr. Xu said pointing out that obesity is worse than inflammation.

The research also pointed out that the enzyme was shown to be only effective in the fat tissue. Previous studies had the enzyme be applied to the liver without any effect in weight and the brain where it lead to an increased weight gain. There are still no hints on a future human trials.

The paper about the research were authored by Ping Jiao as lead author, also of the Hallett Center and Brown. Other authors were Bin Feng, Yaohui Nie, and Yujie Li of the Hallett Center; Jie Ma of Rhode Island Hospital and the Department of Medicine in the Alpert Medical School; and Erin Paul of Brown's Department of Molecular Biology, Cell Biology, and Biochemistry. The research was funded by the American Heart Association.