Metal exposure and Alzheimer's pathogenesis

With the growing aging population in Western countries, Alzheimer's disease (AD) has become a major public health concern. No preventive measure and effective treatment for this burdensome disease is currently available. Genetic, biochemical, and neuropathological data strongly suggest that A beta amyloidosis, which originates from the amyloidogenic processing of a metalloprotein-amyloid precursor protein (APP), is the key event in AD pathology. However, neurochemical factors that impact upon the age-dependent cerebral AD amyloidogenesis are not well recognized. Growing data indicate that cerebral dysregulation of biometals, environmental metal exposure, and oxidative stress contribute to AD pathology. Herein we provided further evidence that both metals (such as Cu) and H2O2 promote formation of neurotoxic A beta oligomers. Moreover, we first demonstrated that laser capture microdissection coupled with X-ray fluorescence microscopy can be applied to determine elemental profiles (S, Fe, Cu, and Zn) in A beta amyloid plaques. Clearly the fundamental biochemical mechanisms linking brain biometal metabolism, environmental metal exposure, and AD pathophysiology warrant further investigation. Nevertheless, the study of APP and A beta metallobiology may identify potential targets for therapeutic intervention and/or provide diagnostic methods for AD. (c) 2006 Elsevier Inc. All rights reserved.