Send a radio signal instead (Image: Superstock)

A radio-controlled mouse might sound like a child’s toy, but this version is flesh and blood and not for playing with. Genetically altered mice have shown that it is possible to regulate processes within the body remotely, opening the door to new ways of treating chronic disease.

Remarkably, the mice can respond to a radio signal by releasing insulin, which lowers blood sugar. One day this might allow people with type 1 diabetes to use an app on their phone to alleviate their disease at a cellular level. Jonathan Dordick of the Rensselaer Polytechnic Institute in New York, who was part of the team that carried out the work, says you can imagine tailoring the technique to treat other disorders, too.

The approach relies on the presence of iron particles, which can absorb energy from radio waves of the right frequency, changing cell behaviour.


Fast control

To test the concept, the team introduced three genes into mouse liver cells. One encoded an iron-containing protein called ferritin. This was placed next to a gene that coded for a protein that acts like a heat-sensitive door, allowing calcium to surge into the cell whenever ferritin was exposed to the radio signal. The third gene coded for insulin but was only active when there was a flood of calcium.

The team hoped this set-up would allow radio waves to trigger insulin release. Sure enough, the engineered mice showed a significant drop in blood glucose for several hours after being exposed to the radio signal.

The work is a long way from being used therapeutically in people, but Dordick says it is a first step to offering fast external control over many conditions. In Parkinson’s disease, for instance, the same approach could be used to lessen jerky movements by delivering dopamine to the brain.

“If it is true that ferritin could be used, this is very good news,” says Arnd Pralle of the University at Buffalo in New York, although he cautions that further work is needed to confirm the results.

Suicide gene

Gene therapies are still seen as an irreversible and potentially risky option, so are being investigated only for conditions that remain hard to treat, such as haemophilia and certain types of blindness. But team member Jeffrey Friedman of Rockefeller University in New York says radio control could make such therapies safer, as the introduced gene could be turned on and off at will.

What’s more, as well as genetically altering liver cells inside mice, the team got the approach to work by modifying mouse stem cells in a dish, then implanting them back into the animals. Such implanted stem cells could be given a “suicide gene” that can be activated to kill them off if they start causing dangerous side effects, says Friedman – another concern with gene therapy.

“Lots of different pieces are coming together at the moment,” says Dordick. “The exciting thing here is the ability to have remote control over the body.”

Journal reference: Nature Medicine, DOI: 10.1038/nm.3730

This article will appear in print under the headline “Point and zap to iron out diabetes”