Drug target could fight Parkinson’s and Alzheimer’s disease

Neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease are in the firing line after researchers identified an attractive therapeutic drug target.

An international collaboration, co-led by University of Queensland researchers, has isolated and analysed the structure and function of a protein found in the brain’s nerve fibres called SARM1.

Dr Jeff Nanson said the protein was activated when nerve fibres were damaged by injury, disease, or as a side effect of certain drugs.

The ring-like structure of the SARM1 protein, developed with X-ray crystallography and cryo-electron microscopy. Credit: The University of Queensland

“After a damaging incident occurs, this protein often induces a form of nerve fibre degeneration – known as axon degeneration – a ‘self-destruct’ mechanism of sorts,” Dr Nanson said.

“This is a key pathological feature of many terrible neurodegenerative diseases, such as Parkinson’s and Alzheimer's disease, and also amyotrophic lateral sclerosis (ALS), traumatic brain injury, and glaucoma.

“There are currently no treatments to prevent this nerve fibre degeneration, but now we know that SARM1 is triggering a cascade of degeneration we can develop future drugs to precisely target this protein.

“This work will hopefully help design new inhibiting drugs that could stop this process in its tracks.”

Professor Bostjan Kobe said the researchers analysed the structure of the protein and defined its three-dimensional shape using X-ray crystallography and cryo-electron microscopy.

“With X-ray crystallography, we make proteins grow into crystals, and then shoot X-rays at the crystals to get diffraction,” Professor Kobe said.

“And with cryo-electron microscopy, we freeze small layers of solution and then visualise protein particles by a beam of electrons.

“The resulting 3D images of SARM1’s ring-like structure were simply beautiful, and truly allowed us to investigate its purpose and function.

“This visualisation was a highly collaborative effort, working closely with our partners at Griffith University and our industry partners.”

The researchers hope that the discovery is the start of a revolution in treatments for neurodegenerative disorders.

“It’s time we had effective treatments for these devastating disorders,” Dr Nanson said.

“We know that these types of diseases are strongly related to age, so in the context of an ageing population here in Australia and globally, these diseases are likely to increase.

“It’s incredibly important that we understand how they work and develop effective treatments.”

Source: The University of Queensland