Australasian Science: Australia's authority on science since 1938

Excess Iron Linked to Alzheimer’s and Parkinson’s

By Stephen Luntz

is excess iron a cause or an effect?

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Both Alzheimer’s and Parkinson’s disease have been linked to failures in a protein that normally removes excess iron from brain cells. Many obstacles exist to treatment, but the discovery holds out the tantalising prospect of addressing the two most devastating neurological diseases in one go.

Both Alzheimer’s and Parkinson’s diseases are associated with iron accumulation in the brain, but there has been debate about whether this is a cause or an effect. Alzheimer’s is also associated with the tau protein, and there is recent evidence this may be more important than the more famous amyloid beta plaques (AS, March 2012, p.6).

Prof Ashley Bush of the Mental Health Research Institute co-authored a paper in Nature Medicine raising the possibility that the problem may not be too much tau, but rather the transformation of tau from its soluble to its insoluble form.

In Alzheimer’s disease tau is observed in neurofibrillary tangles. Less noticed is that this is associated with a reduction in soluble tau. A similar fall in tau is observed in Parkinson’s disease.

Now Bush has shown that one of the functions of tau in a healthy brain is to transport the protein APP to the surface of nerve cells, where it can pump out excess iron. A shortage of soluble tau prevents APP doing its job, allowing iron to build up.

“All cells use bellows to remove iron...

The full text of this article can be purchased from Informit.