Pumping iron raises prospect Parkinson’s and Alzheimer's treatment

Researchers from the Mental Health Research Institute and University of Melbourne have found that an abnormal accumulation of iron in the brain, caused by a malfunctioning protein which helps regulate iron levels, contributes to Parkinson’s and Alzheimer's disease.

The researchers also treated mice with a drug that helps remove excess iron from the brain, reversing some of the effects of the Parkinson’s and Alzheimer’s and raising hopes for a possible future treatment for the neurological diseases.

The protein at the centre of the story, tau, has long been known to be associated with Parkinson’s and Alzheimer’s disease, although the specific mechanism involved was unclear.

It now appears as though tau works to transport another protein, amyloid precursor protein (APP), to the surface of cells, where it escorts excess iron from the premises.

If there are abnormalities in the function of tau, this process can break down, resulting in a build-up of iron in regions of the brain, leading to neurodegeneration.

The researchers used tau knockout mice, which lack the key protein, to see how it affected their neurological function.

As Parkinson’s and Alzheimer’s are both associated with old age, they hypothesised that the mice would only begin degenerating as they aged, and this is precisely what they found.

The tau knockout mice behaved normally for around the first six months, but then experienced neurodegeneration resulting in impaired physical ability by 12 months. At that point, the neurodegeneration plateaued.

Upon examining the brains of the tau knockout mice, the researchers observed neurodegeneration that is characteristic of Parkinson’s, suggesting the tau deficit plays a significant role in the disease.

They then treated some of the tau knockout mice with a drug, clioquinol, which reduces iron levels in key areas of the brain, and found the drug entirely prevented the onset of neurodegeneration.

The discovery not only sheds light on a potential mechanism responsible for causing Parkinson’s and Alzheimer’s disease, but also raises the prospect of a new drug treatment to rid the brain of excess iron.

The paper was published online yesterday at the journal Nature Medicine.