Hot c-cbl mice

A genetically engineered mouse that eats more without gaining weight is the latest in a

long line of cutting edge discoveries by Garvan Institute’s Diabetes & Obesity research team

led by Professor David James.

The paper, published in today’s edition of the prestigious Journal of Clinical Investigation

(USA) demonstrates that mice lacking a specific gene called c-Cbl (pronounced c-sybil)

have a similar body weight to normal mice but have less fat, despite eating

significantly more food.

This remarkable trait appears due to the c-Cbl deficient mice having an increase in body

heat production (a 30% increase in oxygen consumption or metabolic rate) and an

increased core body temperature (higher by 1 degree C).

The mice also have lower amounts of triglycerides and free fatty acids in the blood and

reduced leptin levels - a hormone released from fat involved in regulating appetite.

Otherwise they develop and reproduce normally.

As a result of their lower fat content, the mice also display enhanced insulin action and an

improved ability to utilise blood sugar, making them more resistant to Type 2

diabetes. At a molecular level these effects appear to be due to a change in the way the

skeletal muscle of the mice handle glucose and fatty acid fuels.

“This novel mouse model provides a new avenue for investigating the possibility of

developing drugs that would allow people to eat more without gaining weight, by

converting food to heat (energy) instead of storing it as fat” said Garvan’s Professor

David James.

“Diabetes & Obesity (the ‘diabesity’ epidemic) is a combination of lifestyle and our genes.

Diet and exercise is very important, but only works against the background of our

fundamental genetic make-up” noted Professor John Shine, Executive Director of Garvan

Institute. “ This new insight allows us to develop new approaches to treat our genetic

risk factors as well as the better-known environmental ones.”

Further information contact: Suzie Freebury, PR & Media Manager, Garvan Institute

Tel 02 9295 8112 or 0410 554 775