Amyloid-β Activates Microglia and Regulates Protein Expression in a Manner Similar to Prions

Jian Tu1, Baian Chen, Lifeng Yang

  • 1State Key Laboratories for Agrobiotechnology, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, 100193, Beijing, China, tujian1980@126.com.

Insights

Amyloid-beta (Aβ) aggregates activate microglia similarly to prions, offering new insights into Alzheimer's disease (AD) pathogenesis. Aβ showed higher microglial activation and chemotaxis compared to prions.

Area of Science:

  • Neuroscience
  • Immunology
  • Protein Misfolding Diseases

Background:

  • Prions are known proteinaceous infectious particles.
  • Amyloid-beta (Aβ) aggregates exhibit self-propagation, inducing pathology similar to prion diseases in Alzheimer's disease (AD) models.
  • Gliosis, characterized by activated microglia, is a hallmark of both AD and prion diseases.

Purpose of the Study:

  • To compare the characteristics of microglia activated by Aβ and prions.
  • To gain new insights into the pathogenesis of Alzheimer's disease by analyzing microglial responses.

Main Methods:

  • Utilized BV-2 cells (a model microglia cell line).
  • Exposed BV-2 cells to amyloid-beta 1-42 (Aβ1-42) fibrils and prion peptide (PrP106-126).
  • Assessed microglial activation, proliferation index (PI), chemotaxis index (CI), and expression of monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor beta 1 (TGF-β1).

Main Results:

  • Both Aβ1-42 and PrP106-126 activated BV-2 microglial activity.
  • Aβ1-42 induced a significantly higher chemotaxis index (CI) than PrP106-126 at all tested concentrations.
  • Both Aβ1-42 and PrP106-126 increased the proliferation index (PI) and upregulated MCP-1 and TGF-β1 expression after 12 hours.

Conclusions:

  • Amyloid-beta activates microglia and regulates their protein expression in a manner comparable to prions.
  • These findings provide novel insights into the pathogenesis of Alzheimer's disease, highlighting shared mechanisms with prion diseases.
  • The study underscores the importance of microglial activation in AD pathology.