Alcohol Use Disorder Affects Brain Metals

BackgroundOne of the risks associated with alcohol use disorder (AUD) is dementia. While the exact pathology is unknown, there is increasing evidence that alcohol consumption may dysregulate iron homeostasis in the brain leading to increased brain iron concentrations. Unregulated iron can produce oxidative stress and cellular damage to neurons. Iron-related cellular death is a relatively new finding and is called ferroptosis. To test the hypothesis that alcohol use disorder may cause brain iron dysregulation, we measured iron in hippocampus, caudate and substantia nigra in brain tissues obtained from individuals diagnosed with (AUD) and from individuals with no apparent alcohol-related problems. MethodsWe obtained hippocampus, caudate, and substantia nigra tissues from the New South Wales Brain Tissue Resource Centre, University of Sydney. The tissues came from 20 males and 20 females, half of each diagnosed with AUD. The tissues were wet-ashed and prepared for analysis of iron, copper, and zinc by total x-ray reflectance fluorescence. ResultsIn the hippocampus, we observed AUD-related decreased iron, but nothing more. In the substantia nigra, we observed a significant increase in iron and a trend toward an in increase in copper content in females and decreased iron and zinc in males. In the caudate we saw a near doubling of iron in females and a significant increase in copper in females and males. ConclusionsThese results provide direct evidence that at least part of AUD-related pathophysiology involves the dysregulation of trace metals in the brain. These changes are more severe in females, which may relate to extended levels of exposure due to slower alcohol metabolism.