Asthma - Obesity Link : protein linked to diabetes & obesity now has new role in controlling airway inflammation in asthma

A new asthma gene provides an unexpected link between asthma and obesity according to a research team at Sydney’s Garvan Institute, who are also part of the Cooperative Research Centre for Asthma and Airways.
13 June 2007

A new asthma gene provides an unexpected link between asthma and obesity according
to a research team at Sydney’s Garvan Institute, who are also part of the Cooperative
Research Centre for Asthma and Airways.

Bennett Shum and colleagues have found that a fatty acid binding protein called aP2,
which is already known for its role in diabetes and obesity, is also present in the lung
where it is crucial in controlling inflammation in asthma.

About one in ten adults and one in six children in Australia now suffer from asthma. Its
incidence in Western countries increased markedly over the last 20 years and has
purportedly been linked to the rise in obesity.

“There’s up to three times the risk of being asthmatic if you are obese: the more obese,
the greater the risk. We know that obese asthmatics who lose weight have large
improvements in their asthma,” says asthma project leader Dr Michael Rolph.

Various triggers such as dust mites and pollen bring on asthma attacks, which are
characterized by inflammation of the airways, a tightening of the surrounding muscles, and
excess mucus production.

The scientists used a technique called gene profiling to discover novel genes that regulate
airway inflammation and found very high levels of aP2 in human lung cells that had been
tricked into thinking they were undergoing an asthma attack.

“We were really surprised to find aP2 in the lung”, said Shum. “So, we then looked at what
would happen when we removed this gene in mouse models: mice without aP2 are
protected from asthma attacks”.

“These findings suggest that blocking aP2 function is a novel approach for asthma
treatment and other inflammatory lung diseases,” he added.

Notes to editors:
This research is being published in print in the August issue of the Journal of Clinical
Investigation, but will appear online at 1700 US EST on July 13 2006.
Shum BOV, Mackay CR, Gorgun CZ, Frost M, Kumar RK, Hotamisligil GS, Rolph MS
(2006) The adipocyte fatty acid-binding protein aP2 is required in allergic airway
inflammation.

N.B. This research was funded by the Cooperative Research Centre for Asthma and
Airways. Other authors on the paper include individuals at the Harvard School of Public
Health, Boston, USA; University of New South Wales and St Vincent’s Hospital, Sydney,
Australia.