Identifying Aβ-specific pathogenic mechanisms using a nematode model of Alzheimer's disease

Neurobiol Aging. 2015 Feb;36(2):857-66. doi: 10.1016/j.neurobiolaging.2014.10.016. Epub 2014 Oct 16.

Abstract

Multiple gene expression alterations have been linked to Alzheimer's disease (AD), implicating multiple metabolic pathways in its pathogenesis. However, a clear distinction between AD-specific gene expression changes and those resulting from nonspecific responses to toxic aggregating proteins has not been made. We investigated alterations in gene expression induced by human beta-amyloid peptide (Aβ) in a Caenorhabditis elegans AD model. Aβ-induced gene expression alterations were compared with those caused by a synthetic aggregating protein to identify Aβ-specific effects. Both Aβ-specific and nonspecific alterations were observed. Among Aβ-specific genes were those involved in aging, proteasome function, and mitochondrial function. An intriguing observation was the significant overlap between gene expression changes induced by Aβ and those induced by Cry5B, a bacterial pore-forming toxin. This led us to hypothesize that Aβ exerts its toxic effect, at least in part, by causing damage to biological membranes. We provide in vivo evidence consistent with this hypothesis. This study distinguishes between Aβ-specific and nonspecific mechanisms and provides potential targets for therapeutics discovery.

Keywords: Alzheimer's disease; Beta-amyloid; Dementia; Neurodegeneration; Neurodegenerative disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / genetics
  • Alzheimer Disease / genetics*
  • Alzheimer Disease / metabolism
  • Alzheimer Disease / therapy
  • Amyloid beta-Peptides / genetics*
  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Peptides / toxicity
  • Animals
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Caenorhabditis elegans*
  • Disease Models, Animal
  • Endotoxins
  • Gene Expression / genetics*
  • Hemolysin Proteins
  • Humans
  • Mitochondria / genetics
  • Molecular Targeted Therapy
  • Proteasome Endopeptidase Complex / genetics

Substances

  • Amyloid beta-Peptides
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis
  • Proteasome Endopeptidase Complex