BBC 05 September
2007 [David Haslam]
A single gene can keep in check the
tendency to pile on fat, scientists have shown. The University of Texas team
manipulated the gene, called adipose, to alter the amount of fat tissue laid
down by fruit flies, worms and mice. If
the same effect could be achieved in humans, which also carry the gene, it is
hoped it could lead to new ways to fight obesity and diabetes. The study is published in the journal Cell Metabolism
Lead
researcher Dr Jonathan Graff said: "From worms to mammals, this gene
controls fat formation. "It could
explain why so many people struggle to lose weight, and suggests an entirely
new direction for developing medical treatments that address the current
epidemic of diabetes and obesity. "Maybe
if you could affect this gene, even just a little bit, you might have a
beneficial effect on fat." The
adipose gene was discovered in fat fruit flies more than 50 years ago, but
scientists had not pinned down its exact role. The Texas team used
several methods to turn the gene on and off at different stages of the animals'
lives and in various parts of their bodies.
Their work suggested that the gene acts as a high-level master switch
that tells the body whether to accumulate or burn fat.
Mice with
experimentally increased adipose activity ate as much or more than normal mice. However, they were leaner, had
diabetes-resistant fat cells, and were better able to control insulin and
blood-sugar metabolism. In contrast,
animals with reduced adipose activity were fatter and less healthy, and had
diabetes. The researchers also showed
that gene activity could be turned up or down, not just on or off. Dr Graff said this increased the potential to
manipulate its effect to treat obesity. The
next step will be to probe further the exact mechanisms by which the gene
exerts its control.
David Haslam warned that it could
take many years to develop genetic treatments for obesity. In the meantime, he said, the only way to
tackle the problem effectively was to encourage people to eat healthily and
take exercise. "I don't want
patients coming to me saying: 'It's not what I eat, it's all in my
genes'," he said. "Don't give
my patients another excuse to be victims." |