Photo-oxygenation by a biocompatible catalyst reduces amyloid-β levels in Alzheimer's disease mice

Brain. 2021 Jul 28;144(6):1884-1897. doi: 10.1093/brain/awab058.

Abstract

Amyloid formation and the deposition of the amyloid-β peptide are hallmarks of Alzheimer's disease pathogenesis. Immunotherapies using anti-amyloid-β antibodies have been highlighted as a promising approach for the prevention and treatment of Alzheimer's disease by enhancing microglial clearance of amyloid-β peptide. However, the efficiency of antibody delivery into the brain is limited, and therefore an alternative strategy to facilitate the clearance of brain amyloid is needed. We previously developed an artificial photo-oxygenation system using a low molecular weight catalytic compound. The photocatalyst specifically attached oxygen atoms to amyloids upon irradiation with light, and successfully reduced the neurotoxicity of aggregated amyloid-β via inhibition of amyloid formation. However, the therapeutic effect and mode of actions of the photo-oxygenation system in vivo remained unclear. In this study, we demonstrate that photo-oxygenation facilitates the clearance of aggregated amyloid-β from the brains of living Alzheimer's disease model mice, and enhances the microglial degradation of amyloid-β peptide. These results suggest that photo-oxygenation may represent a novel anti-amyloid-β strategy in Alzheimer's disease, which is compatible with immunotherapy.

Keywords: Alzheimer’s disease; amyloid-β; clearance; microglia; peptide; photo-oxygenation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / pathology*
  • Amyloid beta-Peptides / drug effects*
  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Boron Compounds / pharmacology*
  • Brain / drug effects*
  • Brain / pathology
  • Disease Models, Animal
  • Humans
  • Mice
  • Microglia / metabolism
  • Phototherapy / methods
  • Protein Aggregates / drug effects

Substances

  • 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene
  • Amyloid beta-Peptides
  • Boron Compounds
  • Protein Aggregates