This study looked at the distribution of non-heme iron as well as the expression of the iron-related proteins ferritin, hephaestin and ceruloplasmin as regards the oxidative damage in the brain tissue of 33 people with MS and 30 controls.
The researchers found an age related increase of iron in the white matter of controls and in people with MS with a short disease duration. They found a significant decrease of iron in normal appearing white matter (NAWM) in people with chronic MS.
The decrease of iron in oligodendrocytes and myelin was associated with an up-regulation of iron-exporting ferroxidases. In active lesions, iron was released from dying oligodenrdocytes with a resulting accumulation of extracelluar iron and uptake into microglia and macrophages. These iron containing macrophages showed signs of cell degeneration. At the edge of lesions the researchers found that iron accumulated in astrocytes and axons. Overall, these results show a decrease in iron in NAWM of people with MS with increasing disease duration. The researchers propose that cellular degeneration in MS lesions leads to waves of iron release, which may be involved in the progression of neurodegeneration in addition to the inflammatory oxidative burst.
Authors: Hametner S, Wimmer I
Source: Ann Neurol. 2013 Jul 19. doi: 10.1002/ana.23974. [Epub ahead of print]
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