Study links metals imbalance with Alzheimer’s

Scientists from Australia and the US have published the results of a study linking an imbalance of metals in the brain with Alzheimer's disease.

Much research into Alzheimer’s focuses on the role played by amyloid precursor protein (APP), but to date this line of enquiry has yielded very little in the way of effective treatments. Reports last month that Eli Lilly's latest beta amyloid-based Alzheimer’s drug had failed key clinical indicators was further evidence that researchers may be barking up the wrong tree.

However, this latest report conducted by scientists at Melbourne University and Harvard Medical School focuses on the role that APP plays in exporting iron in and out of neurons in the brain, and presents data that which shows that if this function is impeded, iron builds up in the brain ultimately leading to cell death.

The researchers also demonstrated that incorrect levels of zinc in the brain prevent APP from performing its normal iron transporting role.

The announcement follows the publication earlier in the week of a US study highlighting a new protein which appears to be directly responsible for increasing levels of beta amyloid in the brain, a key indicator of Alzheimer’s disease. Most existing Alzheimer’s drugs work by suppressing an enzyme called gamma secretase, which produces beta amyloid.

The fact that gamma secretase has several other important functions is thought to be one of the main reaons why this class of drugs has so far been unsuccessful in treating Alzheimer’s.

One of the authors of this latest report, published this week in the journal Cell, is Professor Ashley Bush, co-founder of Australian company Prana Biotechnology. Prana is currently conducting Phase II trials of a new drug called PBT2, which is designed to restore normal levels and distribution of metals in the brain, including zinc, levels of which typically fluctuate with ageing.

It is also hoped that PBT2 may be able to help reverse brain damage in Alzheimer’s disease.

Prana Biotechnology’s shares closed today up one cent to $0.135.