Iron, amyloid precursor protein, and Alzheimer’s

amyloid beta plaques

Amyloid precursor protein (APP) mRNA has an iron response element (IRE) in the 5′ untranslated region. Iron regulatory 1 (IRP1) and and iron regulatory protein 2 (IRP2) when bound to the IRE in the 5′ untranslated region destablize transcripts of iron regulated proteins. IRP1 and IPR2 when bound to the IRE in amyloid precursor protein mRNA decrease translation of APP. Iron decreases levels of IRP1 and IRP2. A point of iron chelators in Alzhemeir’s disease is by decreasing iron levels to increase levels of IRP1 and IRP2 thereby decreasing transcripition of APP.

APP is the precusor of amybloid beta protein. Amyloid beta can form plaques which are associated with Alzheimer’s disease. Iron chelators by decreasing APP levels would decrease levels of amyloid beta protein which was thought for decades to be a very good thing. Very effective treatments for Alzheimer’s appeared imminent.

A very serious difficulty arose. Drugs that reduce levels of amyloid beta do not treat or slow the progression of Alzheimer’s disease.

APP can looked at from a different angle. Amyloid precursor protein when ablated increases iron retention in cells by decreasing iron export. Loss of tight control of APP translation not high levels of APP could be what is causing iron retention in neurons.

What I have been arguing is that IRP1 is dysregulated in a range of neurological illnesses, such as Alzheimer’s and that this can lead to iron accumulation in neurons and cell death. Tight control of iron levels, not reducing iron levels via iron chelation, could be part of a treatment for various neurological illnessse such as Alzheimer’s disease.

A meta-analysis indicate that serum iron is significantly lower in Alzheimer’s patients than in controls. Supplmental iron carbonyl given three time a day could be part of a treatment for Alzheimer’s disease. The goal, of course, would not be high iron levels but rather tightly regulated levels of IRP1 and IRP2. Iron homeostasis could be upset in Alzheimer’s disease which is a much different way of loooking at iron than ‘iron is toxic’ in Alzheimer’s disease.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.