A study published in the Journal of Neuroscience has implicated a new biological pathway in the development Alzheimer's disease.
Using an improved animal model of the disease, the researchers found that immune cells called microglia that normally protect the brain, abnormally consume an important nutrient called arginine. Blocking this process with a small molecule drug prevented the development of brain plaques and memory loss in the mice. However, the researchers did not determine whether blocking arginine metabolism can prevent the death of brain cells that occurs in Alzheimer's disease.
The immune system is increasingly implicated in the development of dementia. This study points to a new potential mechanism linking the immune system and Alzheimer's disease that could eventually lead to the development of new treatments.
Dr James Pickett, Head of Research at Alzheimer's Society said:
'This study in animals joins some of the dots in our incomplete understanding of the processes that cause Alzheimer's disease, in particular around the role played by the immune system.
'Using a new animal model of Alzheimer's, the researchers have found that depletion of a nutrient called arginine occurs in the damaged brain areas. Blocking the use of arginine reduced some of the disease hallmarks and improved memory performance, offering hope that these findings could lead to new treatments for dementia.
'Importantly, these new findings reflect earlier observations that arginine is reduced in the brains of people with Alzheimer's disease. The next step would be to show that targeting arginine metabolism in the brain can reduce the death of brain cells, as this was not shown in the current study.'