Making metabolism more inefficient can reduce obesity

Oct 03, 2008

In a discovery that counters prevailing thought, a study in mice has found that inactivating a pair of key genes involved in "fat-burning" can actually increase energy expenditure and help lower diet-induced obesity. These unusual findings, appearing this week in the JBC, might lead to some new roads in weight-loss therapy.

Humans and other warm-blooded animals need to continually "burn fat" in order to maintain body temperature, and it's currently believed that an individual's fat-burning capacity, or thermogenic potential, is connected with obesity risk; that is, people with more thermogenic potential are less likely to become obese. In fact, bodybuilders and dieters looking to burn fat commonly use thermogenic supplements like ephedra.

In theory, lowering thermogenesis should increase the chances of obesity, but Leslie Kozak and colleagues at Pennington Biomedical Research Center found that this may not be the case. They knocked-out two thermogenic genes in mice, Ucp1 (mitochondrial uncoupling protein) and Gdm (glycerol 3-phosphate dehydrogenase) and then fed the mice a high-fat diet while rearing them at a cool 20 °C (68 °F).

Surprisingly, these mice were actually quite resistant to obesity, which resulted from the mice turning on backup heat generators, so to speak. Lacking Ucp1 and Gdm, genes that have been designed for the efficient production of heat, mouse white fat cells activated alternate, and more inefficient, fat burning pathways. In this case, though, inefficiency is beneficial, as the mice had to burn more fat than normal to stay warm (by analogy you burn more wood by warming your house with an open fire then with a well designed wood stove).

Importantly, after spending 10 weeks at 20 °C the mice retained these alternate pathways even after transferring to 28 °C (82 °F), suggesting their bodies had adapted to the change. Thus, Kozak and colleagues note, fat burning does not necessarily require making thermogenesis easier; by making it harder and forcing the body to use inefficient methods to stay warm, the same goals can be reached.

Source: American Society for Biochemistry and Molecular Biology

Explore further: Novel marker discovered for stem cells derived from human umbilical cord blood

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

New pain relief targets discovered

4 hours ago

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

Building 'smart' cell-based therapies

4 hours ago

A Northwestern University synthetic biology team has created a new technology for modifying human cells to create programmable therapeutics that could travel the body and selectively target cancer and other ...

Proper stem cell function requires hydrogen sulfide

7 hours ago

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study from the Center for Craniofacial Molecular Biology at the Herman Ostrow School of Dentistry ...

User comments : 0

More news stories

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Researchers discover target for treating dengue fever

Two recent papers by a University of Colorado School of Medicine researcher and colleagues may help scientists develop treatments or vaccines for Dengue fever, West Nile virus, Yellow fever, Japanese encephalitis and other ...

Our brains are hardwired for language

A groundbreaking study published in PLOS ONE by Prof. Iris Berent of Northeastern University and researchers at Harvard Medical School shows the brains of individual speakers are sensitive to language univer ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...