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Rapid Generation of Amyloid from Native Proteins In vitro
05:48

Rapid Generation of Amyloid from Native Proteins In vitro

Published on: December 5, 2013

Amyloid-beta fibril formation is not necessarily required for microglial activation by the peptides

Sadayuki Hashioka1, Akira Monji, Tadashi Ueda

  • 1Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Neurochemistry International
|July 12, 2005
PubMed

Insights

Microglial activation plays a role in Alzheimer's disease. This study shows amyloid-beta (Abeta) fibril formation is not essential for activating microglia or producing tumor necrosis factor-alpha (TNF-alpha).

Area of Science:

  • Neuroscience
  • Immunology
  • Biochemistry

Background:

  • Microglial activation by amyloid-beta (Abeta) peptides contributes to Alzheimer's disease pathogenesis.
  • Activated microglia release neurotoxic molecules, damaging neurons.
  • The link between Abeta peptide aggregation state and microglial activation is poorly understood.

Purpose of the Study:

  • To investigate the relationship between the aggregation state of Abeta peptides and their ability to activate microglia.
  • To clarify how Abeta peptide structure influences microglial activation and neuroinflammation.

Main Methods:

  • Structural and biochemical studies were performed on Abeta peptides.
  • Microglial activation and TNF-alpha production were assessed in the presence of interferon-gamma.
  • Thioflavine-T fluorometric assay was used to measure amyloid fibril formation.

Main Results:

  • Abeta25-35(M(35)Nle) peptide showed similar potency in activating microglia and producing TNF-alpha as Abeta25-35 peptide.
  • This occurred despite significantly less amyloid fibril formation by Abeta25-35(M(35)Nle) compared to Abeta25-35.
  • Results were observed at both protein and mRNA levels.

Conclusions:

  • Amyloid fibril formation by Abeta peptides is not a prerequisite for microglial activation.
  • These findings suggest alternative mechanisms by which Abeta peptides can trigger neuroinflammatory responses in Alzheimer's disease.

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