Paris (AFP) – Scientists on Thursday said they had tested a drug that in mice prevented the death of brain cells, boosting hopes in the fight against Alzheimer’s, Parkinson’s and other neurodegenerative diseases.
Still at a very early and experimental stage, the drug blocks disruption of a defence system in the brain which plays a common role in these tragic disorders.
Many brain diseases start with the buildup of rogue, scrunched-up proteins, or amyloids.
The organ’s response to this is to switch on a defence mechanism called the unfolded protein response, or UPR.
The mechanism orders cells to stop producing new proteins so that the problem is not worsened.
But the buildup of misshapen proteins prevents the UPR mechanism from being switched off.
As a result, the misshapen proteins are no longer made — but nor are normal proteins that are essential for brain-cell survival. Neurons start to die, are not replenished, and the disease progresses.
British researchers, reporting in the US journal Science Translational Medicine, tested a drug that works on a key point in this switching pathway, an enzyme called PERK, to keep protein production open.
Known by its lab name as GSK2606414 — it is made by British drugmaker GlaxoSmithKline — the orally-administered drug was tested on 29 mice with prion disease, a family of disorders that includes Creuzfeldt-Jakob disease.
These were compared against a group of “control” mice, whose brain had also been infected with prions but which did not receive the drug.
Mice that were treated seven weeks after being infected with the prions suffered no memory loss in a test to recognise a familiar object, but those treated at nine weeks lost their memory.
The mice were killed and autopsied, and examination of samples under a microscope confirmed that brain-cell death among all the treated mice was very low, although less so among the nine-week group.
The University of Leicester team say they are hugely buoyed by the success, although many more years of tests lie ahead.