β-Amyloid augments platelet aggregation: Reduced activity of familial angiopathy-associated mutants

Abstract

The β-amyloid (Aβ) peptide is present both in serum and in platelets, however it is unclear whether Aβ plays a role in platelet function. We have now investigated the effects of soluble Aβ on platelet function and have found that low levels (0.1-1 nM) of soluble Aβ augment ADP-dependent platelet aggregation and translocation of focal adhesion kinase to the platelet cytoskeleton. Addition of Aβ to gel-filtered platelets along with concentrations of adenosine diphosphate (ADP) producing submaximal aggregation responses increased the aggregation response by over 2-fold depending on the ADP:Aβ ratios. The structure activity requirements for Aβ activity showed intriguing constraints. Only full le..