Affiliations: Department of Biochemistry and Molecular Biology, Instituto de Neurociencias de Castilla y León (INCYL), University of Salamanca, Spain
Correspondence:
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Corresponding author: José M. Medina, Instituto de Neurociencias de Castilla y León (INCYL), c/ Pintor Fernando Gallego 1, 37007 Salamanca, Spain. Tel.: +34 923 294500 Ext. 5313; Fax: +34 923 294564; E-mail: medina@usal.es.
Abstract: Amyloid-β (Aβ) is the main component of senile plaques, one of the hallmarks of Alzheimer's disease. Our results showed that Aβ25-35 decreased neuronal viability while it increased generation of reactive oxygen species (ROS). Under these circumstances, albumin (BSA) prevented ROS production and neuronal death in a dose- and time-dependent manner. In addition, BSA partially prevented the decrease in the expression of GAP-43, MAP-2, and tubulin, and the phosphorylation of tau protein caused by Aβ, suggesting that BSA protects against the loss of plasticity caused by the peptide. Our findings suggest that BSA exerts its protective effect by binding to Aβ in an equimolecular way, which prevents heterodimer (Aβ-BSA) entry into neurons. In fact, BSA prevented Aβ internalization, as shown by confocal immunocytochemistry, suggesting that BSA causes its protective effect by sequestrating Aβ, which cannot reach its intracellular targets. This is consistent with the idea that Aβ must enter neurons to exert its deleterious effects.
