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 analyzed the structure and function of a protein found in the brain's nerve fibers called SARM1.
Dr Jeff Nanson said the protein was activated when nerve fibers were damaged by injury, disease, or as a side effect of certain drugs.
After a damaging incident occurs, this protein often induces a form of nerve fiber degeneration - known as axon degeneration - a 'self-destruct' mechanism of sorts.
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 fiber 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."
Dr Jeff Nanson, Researcher, University of Queensland
Professor Bostjan Kobe said the researchers analyzed 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 visualization 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 aging 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."
Figley, M.D., et al. (2021) SARM1 is a metabolic sensor activated by an increased NMN/NAD+ ratio to trigger axon degeneration. Neuron. doi.org/10.1016/j.neuron.2021.02.009.