Tiny magnetic iron crystals in the brain may be linked to the development of Alzheimer鈥檚 disease, suggests preliminary research.
If further work confirms the hypothesis, it could be possible to diagnose patients with early Alzheimer鈥檚 disease by measuring the level of iron oxide crystals, called magnetite, in their brains.
Jon Dobson at the University of Keele, UK, and his colleagues examined six brain samples and found that magnetite levels increased with Alzheimer鈥檚 disease severity, the first time such a link has been shown. 鈥淚f the data continues to go this way, the implications are quite profound,鈥� he told 快猫短视频.
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Dobson says it has been known for 50 years that there is an association between excess iron and Alzheimer鈥檚 disease, but that scientists had been baffled by the form in which this iron occurs.
鈥淭his is a very interesting hypothesis that definitely needs some further research,鈥� says Richard Harvey, director of research at the UK Alzheimer鈥檚 Society. 鈥淏ut the data is from very, very limited samples so you can鈥檛 draw any conclusions other than to say it鈥檚 interesting and fits into some of the theories of Alzheimer鈥檚.鈥�
Dobson鈥檚 group will now look at iron compounds in more brain samples. They will also examine samples from patients with other neurodegenerative diseases that are also linked to excess iron, such as Parkinson鈥檚 and Huntingdon鈥檚 disease. This further work will be part-funded by the UK Alzheimer鈥檚 Society.
Early detection
The team measured magnetite in brain tissue taken from patients who died from Alzheimer鈥檚. They used a technique called SQUID (superconducting quantum interference device) magnetometry, which measures the samples鈥� responses to different magnetic fields.
In the three samples from Alzheimer鈥檚 patients, increasing levels of the crystal correlated with the increasing severity of the disease in that patient. Two of the three control samples showed no magnetite at all. But the third sample had low levels of magnetite despite the person having had no clinical signs of the Alzheimer鈥檚 before they died.
When the team looked this person鈥檚 brain in detail they found changes associated with the devastating disease, such as the formation of plaques. 鈥淭he nice thing about that was that we were able to pick it up in magnetite measurements before clinical measurements,鈥� Dobson says.
Detecting early stage Alzheimer鈥檚 would be 鈥渧ery beneficial鈥�, he says, as patients they could be treated promptly with the new therapies that are now emerging.
Free radicals
Magnetite could cause disease in two ways, says Dobson. It is capable of generating free radicals, which damage cells, particularly in the brain. Also, because the crystal is strongly magnetic, it may interfere with ordinary biochemical reactions within cells, which may also lead to the formation of free radicals.
Harvey says Alzheimer鈥檚 disease is known to be associated with two proteins: amyloid proteins that cause plaques in the brain, and tau proteins that cause nerve cells to tangle.
鈥淲hat we don鈥檛 know is what triggers their production,鈥� he told 快猫短视频, but it is 鈥渏ust plausible鈥� that magnetite will provide the answer.
Journal reference: Biology Letters (DOI: 10.1098/rsbl.2003.0012)