Novel drug therapies for obesity and diabetes may come from new understanding of how the body converts fat for storage, rather than fuel.
Scientists at the University of Texas Health Science Center say the mTORC1 molecular pathway controls the conversion of white fat into beige fat, a process regulated by the Grb10 protein. The resulting adipose tissue from the conversion serves as a regulator of metabolism, with excessive amounts of white adipose tissue associated with chronic diseases such as obesity and type 2 diabetes.
But more broadly, greater knowledge about this molecular pathway may inform the future treatment of a broad range of diseases including cardiovascular and metabolic diseases, senior study author Feng Liu said in a press statement. "We know that if we want to keep our body lean, we have to get rid of extra nutrients in the body, which means burning more energy," he said. "Understanding how beigeing is controlled is so very important because if we can improve energy expenditure, we can reduce obesity.”
A good target for increasing energy expenditure is that white adipose tissue stored at the caprice of Grb10, according to co-author Lily Dong, a professor of cellular and structural biology at the university. "For the extra food we eat, it is better to release it, not store it,” she said in the statement. So finding a way to turn the white fat into beige and burn the energy that [we normally] store would have high therapeutic potential for the treatment of obesity and its related diseases. Dr. Liu has identified the pathway to do this.”
The possible new direction for obesity therapy comes as the United States, among other Westernized nations, grows increasingly more obese at 34.9 percent of adults, according to the Centers for Disease Control and Prevention. Among leading causes of death today are obesity and related illnesses including heart disease, stroke, type 2 diabetes, and some forms of cancer. The costs of treating obesity-related illnesses in America in 2008 was $147 billion, with average medical costs $1,429 per year higher for people with obesity.
The study was published on Friday in the journal Cell Metabolism.
Source: Liu M, Bai J, He S, et al. Grb10 Promotes Lipolysis and Thermogenesis by Phosphorylation-Dependent Feedback Inhibition of mTORC1. Cell Metabolism. 2014.