Rodent of the Week: Carb gene found!
This article was originally on a blog post platform and may be missing photos, graphics or links. See About archive blog posts.
Imagine you’ve bellied up to the all-you-can-eat pasta bar in Berkeley, Calif., only to meet one of the mice from Hei Sook Sul’s Nutritional Science and Toxicology Lab. (Work with me here.)
Now, if you come here often, you know that loading up on carbohydrates is going to make you pretty chubby. But you notice your fellow diner -- the mouse -- is pretty slim. How does he do it?
This lucky mouse has had a gene knocked out of his genome by researchers in Hei Sook Sul’s lab. The observation that mice without this gene can eat all the carbs they want and stay slim -- while other mice fed a high-carb diet do indeed become fat -- leads Dr. Sul to conclude that her lab has found a gene that plays a critical role in the process of converting carbohydrates to fat. And that discovery points to an important new target for drug developers hoping to find a way to prevent and perhaps even reverse obesity in humans.
The discovery of the gene’s role in obesity is published in an article in the March 20 issue of the journal Cell.
The gene involved, known as DNA-PK (short for DNA-dependent protein kinase), is widely studied for its role in repairing breaks in the DNA -- a function that has made it critical to cancer research and treatment. But Sul says it was a surprise to discover that the same gene has a key role in the liver’s conversion of excess glucose (all that bread, pasta and sugary soda you’ve failed to work off) to fatty acids.
Not only were mice whose DNA-PK gene had been knocked out 40% leaner than normal mice when all were fed a high-carb, low-fat diet. They also had better blood-lipid profiles, suggesting they’d be at lower risk of developing heart disease.
In an interview, Sul said no one at this point is thinking about gene therapy as a treatment for obesity -- that would be way down the road. Instead, drug developers might look at how the DNA-PK gene calls out other actors to set in motion the conversion of excess calories to fat and find an agent that might disrupt the process.
And if they’re successful, you’ll be able to join that mouse at the all-you-can-eat pasta bar and look just as svelte as he does.
-- Melissa Healy
