Clioquinol promotes the degradation of metal-dependent amyloid-ß (Aß) oligomers to restore endocytosis and ameliorate Aß toxicity

Academic Article

Abstract

  • Alzheimer's disease (AD) is a common, progressive neurodegenerative disorder without effective disease-modifying therapies. The accumulation of amyloid-ß peptide (Aß) is associated with AD. However, identifying new compounds that antagonize the underlying cellular pathologies caused by Aß has been hindered by a lack of cellular models amenable to high-throughput chemical screening. To address this gap, we use a robust and scalable yeast model of Aß toxicity where the Aß peptide transits through the secretory and endocytic compartments as it does in neurons. The pathogenic Aß 1-42 peptide forms more oligomers and is more toxic than Aß 1-40 and genome-wide genetic screens identified genes that are known risk factors for AD. Here, we report an unbiased screen of ̃140,000 compounds for rescue of Aß toxicity. Of ̃30 hits, several were 8-hydroxyquinolines (8-OHQs). Clioquinol (CQ), an 8-OHQ previously reported to reduce Aß burden, restore metal homeostasis, and improve cognition in mouse AD models, was also effective and rescued the toxicity of Aß secreted from glutamatergic neurons in Caenorhabditis elegans. In yeast, CQ dramatically reduced Aß peptide levels in a copper-dependent manner by increasing degradation, ultimately restoring endocytic function. This mirrored its effects on copper-dependent oligomer formation in vitro, which was also reversed by CQ. This unbiased screen indicates that copper- dependent Aß oligomer formation contributes to Aß toxicity within the secretory/endosomal pathways where it can be targeted with selective metal binding compounds. Establishing the ability of the Aß yeast model to identify disease-relevant compounds supports its further exploitation as a validated early discovery platform.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Matlack KES; Tardiff DF; Narayan P; Hamamichi S; Caldwell KA; Caldwell GA; Lindquist S
  • Start Page

  • 4013
  • End Page

  • 4018
  • Volume

  • 111
  • Issue

  • 11