Scientists in the US have discovered a potential new cause for Alzheimer's, and have used an existing drug to halt the progression of the disease and memory loss in mice.
The team, from Duke University in the US, figured out that when a person has Alzheimer's, the immune cells turn against the body and start consuming a nutrient called arginine. Arginine plays a crucial role in cell division, wound healing, immune function, and hormone regulation, and when levels in the brain are reduced, structures called amyloid plaques are allowed to accumulate and cause the memory loss and decline in cognitive function that are characteristic of Alzheimer's disease.
The finding is important because not only does it give researchers another avenue through which to explore treatment options, but it gives them a new possible cause for Alzheimer's disease, which has proven frustratingly elusive.
"We see this study opening the doors to thinking about Alzheimer's in a completely different way, to break the stalemate of ideas in Alzheimer's disease," one of the team, neurologist Carol Colton told Charlie Cooper at The Independent. "The field has been driven by amyloid for the past 15, 20 years and we have to look at other things because we still do not understand the mechanism of disease or how to develop effective therapeutics."
Publishing in the Journal of Neuroscience, the team describes how they used a drug called difluoromethylornithine (DFMO) to treat the arginine-eating immune systems of mice with Alzheimer's. This drug is also being used in trials to treat different types of cancer, Cooper reports, which means if it ends up being a viable option for Alzheimer's treatment, it could get approval much quicker than if it was a brand new drug.
The team watched as the DFMO drug stopped the reduction of arginine in the brains of the mice, and this in turn prevented the build-of sticky amyloid plaques. Both memory and cognitive function remained at healthy levels.
While mice are very different from humans, the results are encouraging, and the next step will be to see if they can be replicated in clinical trials. "Clinical trials are essential before any potential new treatment can be given to people, but these early findings could open new doors for future treatment development for Alzheimer's," Laura Phipps from Alzheimer's Research UK, who was not involved in the research, told The Independent. "The study suggests that low levels of arginine in the brain could contribute to the death of nerve cells in Alzheimer's, but there is much more we still need to understand about how and why nerve cells die in the disease."
It's early days, but for those working in a field like Alzheimer's research, where decades and entire careers have been dedicated to finding an effective treatment and/or method of prevention, an opportunity to focus on something new, such as arginine depletion, is no doubt extremely welcome. We'll just have to wait and see where it will take us.
Source: The Independent