Raloxifene alleviates amyloid-β-induced cytotoxicity in HT22 neuronal cells via inhibiting oligomeric and fibrillar species formation

J Biochem Mol Toxicol. 2019 Nov;33(11):e22395. doi: 10.1002/jbt.22395. Epub 2019 Oct 4.

Abstract

Raloxifene, a selective estrogen receptor modulator, displays benefits for Alzheimer's disease (AD) prevention in postmenopausal women as hormonal changes during menopause have the potential to influence AD pathogenesis, but the underlying mechanism of its neuroprotection is not entirely clear. In this study, the effects of raloxifene on amyloid-β (Aβ) amyloidogenesis were evaluated. The results demonstrated that raloxifene inhibits Aβ42 aggregation and destabilizes preformed Aβ42 fibrils through directly interacting with the N-terminus and middle domains of Aβ42 peptides. Consequently, raloxifene not only reduces direct toxicity of Aβ42 in HT22 neuronal cells, but also suppresses expressions of tumor necrosis factor-α and transforming growth factor-β induced by Aβ42 peptides, and then alleviates microglia-mediated indirect toxicity of Aβ42 to HT22 neuronal cells. Our results suggested an alternative possible explanation for the neuroprotective activity of raloxifene in AD prevention.

Keywords: Alzheimer's disease; aggregate disassembly; amyloid-β; cytotoxicity; raloxifene.

MeSH terms

  • Alzheimer Disease / prevention & control
  • Amyloid beta-Peptides / chemistry
  • Amyloid beta-Peptides / toxicity*
  • Animals
  • Cell Line
  • Cell Survival / drug effects
  • Gene Expression / drug effects
  • Hydrophobic and Hydrophilic Interactions
  • Mice
  • Microglia / cytology
  • Microglia / metabolism
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuroprotective Agents / chemistry
  • Neuroprotective Agents / pharmacology*
  • Peptide Fragments / chemistry
  • Peptide Fragments / toxicity*
  • Protein Aggregates / drug effects*
  • Protein Aggregation, Pathological / metabolism
  • Protein Domains
  • Raloxifene Hydrochloride / chemistry
  • Raloxifene Hydrochloride / pharmacology*
  • Transforming Growth Factor beta / genetics
  • Tumor Necrosis Factor-alpha / genetics

Substances

  • Amyloid beta-Peptides
  • Neuroprotective Agents
  • Peptide Fragments
  • Protein Aggregates
  • Transforming Growth Factor beta
  • Tumor Necrosis Factor-alpha
  • amyloid beta-protein (1-42)
  • Raloxifene Hydrochloride