Scientists identify protein that stimulates brown fat to burn calories

(Press-News.org) Scientists have identified a protein which regulates the activation of brown fat in both the brain and the body's tissues. Their research, which was conducted in mice, was published today, Friday 11 May, in the journal Cell.

Unlike white fat, which functions primarily to store up fat, brown fat (also known as brown adipose tissue) burns fats to generate heat in a process known as thermogenesis. The research, led by scientists at the University of Cambridge Metabolic Research Laboratories at the Institute of Metabolic Science, discovered that the protein BMP8B acts on a specific metabolic system (which operates in the brain and the tissues) to regulate brown fat, making it a potential therapeutic target.

The scientists believe that activating brown fat could help to support current weight loss programmes, which individuals often struggle to maintain.

Dr Andrew Whittle, one of the authors of the paper from the Institute of Metabolic Science, said: "Other proteins made by the body can enhance heat production in brown fat, such as thyroid hormone but often these proteins have important effects in other organs too. Therefore they are not good targets for developing new weight loss treatments. However, BMP8B seems to be very specific for regulating the heat producing activity of brown fat, making it a more ideal mechanism for new therapies."

The experiments showed that when mice lacked the protein BMP8B they found it more difficult to maintain their normal body temperature. They also became much more obese than normal mice, particularly when fed a high-fat diet. Additionally, when the researchers treated brown fat cells with BMP8B they responded more strongly to activation by the nervous system. Furthermore, when BMP8B was administered to specific parts of the brain it increased the amount of nervous activation of brown adipose tissue. The result was that these BMP8B-treated brown fat cells burned more fat and mice given BMP8B in the brain lost weight.

Professor Toni Vidal-Puig, lead author of the study from the Institute of Metabolic Science and a member of the MRC Centre for Obesity and Related Metabolic Diseases, said: "A major feature of current weight-loss strategies is that people lose a lot of weight early on, but then reach a plateau despite continuing to follow the same diet regime. This is because the human body is incredibly good at sensing a reduction in food consumption and slows the metabolic rate to compensate. A strategy to increase brown fat activity could potentially be used in conjunction with current weight loss strategies to help prevent the typical decrease in a person's metabolic rate.

"One could be sceptical that techniques to increase metabolic rate might just be compensated by the body trying to make you want to eat more, to fuel this increased metabolism. But our findings showed that treating mice with Bmp8b did not have this effect, it simply made them lose weight by burning more fat in their brown adipose tissue.

"There are obvious differences between mice and humans, and from a therapeutic perspective this work is preliminary. Validation will be necessary to see if manipulating BMP8B would be safe and effective in humans."

###The research was funded by the Medical Research Council (MRC), the Wellcome Trust, and the Biotechnology and Biological Sciences Research Council (BBSRC).

For additional information please contact: Genevieve Maul, Office of Communications, University of Cambridge
Tel: direct, +44 (0) 1223 765542, +44 (0) 1223 332300
Mob: +44 (0) 7774 017464
Email: Genevieve.maul@admin.cam.ac.uk

Notes to editors:

1. The paper 'BMP8B Increases Brown Adipose Tissue Thermogenesis through Both Central and Peripheral Actions' will appear in the journal CELL on Friday, 11 May. Volume: 149; Issue: 4; Manuscript: 6246; DOI: 10.1016 2. MRC
For almost 100 years the Medical Research Council has improved the health of people in the UK and around the world by supporting the highest quality science. The MRC invests in world-class scientists. It has produced 29 Nobel Prize winners and sustains a flourishing environment for internationally recognised research. The MRC focuses on making an impact and provides the financial muscle and scientific expertise behind medical breakthroughs, including one of the first antibiotics penicillin, the structure of DNA and the lethal link between smoking and cancer. Today MRC funded scientists tackle research into the major health challenges of the 21st century. www.mrc.ac.uk 3. About the Wellcome Trust
The Wellcome Trust is a global charitable foundation dedicated to achieving extraordinary improvements in human and animal health. It supports the brightest minds in biomedical research and the medical humanities. The Trust's breadth of support includes public engagement, education and the application of research to improve health. It is independent of both political and commercial interests. www.wellcome.ac.uk 4. About BBSRC
BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond. Funded by Government, and with an annual budget of around £445M, we support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals. For more information about BBSRC, our science and our impact see: http://www.bbsrc.ac.uk For more information about BBSRC strategically funded institutes see: http://www.bbsrc.ac.uk/institutes