The Universal Drug Against Pain on the Way

There is no worse invention belonging to nature than pain. That gets even worse in the case of chronic pain, which unlike the acute pain linked with trauma, has no apparent physiological benefit and it is often called the "disease of pain". Complete and lasting relief of chronic pain is hard to achieve and often implies more than one drug.

Now one of the simplest organisms encountered in nature could expose the structure of a crucial molecule in controlling human pain. This could lead to a quick advanced investigation into the next generation of painkillers for easing chronic issues like migraine and backache.

The research team at the University of Manchester has investigated microscopic amoeboid protozoan organisms commonly named slime moulds to get further knowledge on the pain molecules called 'P2X receptors'.

"In humans, P2X receptors look identical to one another and so scientists have had difficulty understanding how they function. By looking at slime mould we were effectively able to turn the evolutionary clock back a billion years to see how a more primitive P2X molecule functions." said Dr Chris Thompson, who carried out the investigation together with Professor Alan North and Dr Sam Fountain in the Faculty of Life Sciences.

They found just a 10% similarity between human P2X and the slime mould counterpart. Based on the evolutionary theory, these similar parts of the molecule could be those regulating pain in humans.

"It's a big step forward in understanding how the molecule works and should make it possible to develop drugs that block the receptors' actions. Inhibiting P2X as a potential pain-relief therapy would be the Holy Grail of rational drug design and could revolutionize the way we manage chronic pain conditions like back pain and migraine." said Thompson.

The slime mould Dictyostelium is a kind of amoeba-like organism feeding off bacteria in the soil. If the food is getting scarcer, the moulds aggregate forming a 'fruiting body' of some 100,000 cells. Some of these cells turn into spores, while others build a stalk beneath the soil surface. The stalk cells die; but their sacrifice ensures the spread of the spores to new feeding areas.