It sounds almost too good to be true: contained within the simple brains and biochemistry of the humble fruit fly may hide the answer to the obesity and diabetes trend that is sweeping across our nation. Despite advances in medicine, sports science, and nutrition, the population of the US has become ever fatter and more prone to becoming diabetic, to the point where many are calling the number one health crisis on hand. Yet this October’s issue of Genetics, available online today, reveals a fascinating study by neurobiologists at Wake Forest that might hold the secret to reversing this trend once and for all.
The question Erik Johnson, associate professor of biology, and his research team asked was simple: how do fruit flies respond to restricted diets? What they saw was that when starved the flies would enter a state of high energy, almost a frenzy as they flew around desperately looking for food. They discovered that this happens because their hunger releases an enzyme called AMP-activated kinase, whose job it is to cause the creation of large quantities of the adipokinetic hormone. This hormone tells the fruit fly’s little body to tap into its energy source by releasing sugar into its system, which in turn causes it to become hyper.
So what, you might ask? It turns out that the fruit fly adkipokinetic hormone has a human parallel: glucagon. This is the opposite of insulin, as it stimulates our body to release glucose into our bloodstream, depleting our stores, whereas insulin’s job is to shepherd excess glucose back into our fat cells and liver. So when Erik Johnson managed to turn off the fly’s AMP-activated kinase and prevent the stimulation of adipokinetic hormone, he not only managed to prevent the flies from becoming hyper in the face of starvation, but he also so the potential parallels and benefits for humans.
How could this help? Take diabetes. The great difficulty any diabetic has is in handling raised levels of blood sugar, which is why they have to take insulin shots in order to lower those very levels. Learning how to control a fly’s adipokinetic hormone release could be transposed over to controlling a human’s glucagon production, which releases blood sugar into the blood. If you stop the glucagon, you don’t get high levels of blood sugar, and you rule out the necessity for insulin shots.
What about weight loss? It turns out that exercise stimulates the release of AMP-activated kinase, which stimulates all the benefits that exercise gives us. Learning how to manipulate our own enzyme would allow us to trick the body into thinking we are exercising—without doing the exercise.
Yet how can the discovery within a fly map over to a vastly more complex creature such as a human being? Even though a fruit fly has only 100,000 neurons versus a human’s 11 billion, we still share about 30 percent of the same genetic code—and what’s more surprising, our brains are wired in the same manner. This base level similarity makes it possible to extrapolate discoveries from fruit flies and use them as road maps to approach the same goals in a human being, giving the biologists at Wake Forest—and ourselves—an exciting chance at creating new drugs that could change our lives and society forever.