Effect of the aggregation state of amyloid-beta (25-35) on the brain oxidative stress in vivo

PLoS One. 2024 Oct 29;19(10):e0310258. doi: 10.1371/journal.pone.0310258. eCollection 2024.

Abstract

Aggregation pathway of amyloid-β (25-35) in water affects the oxidative stress in the brain observed after administration of aggregated peptide in animals in vivo. Our studies on peptide aggregation ex situ prior to injection suggest that from the onset of peptide incubation in aqueous media, all samples exhibit the formation of fibril-like aggregates, characterized by a significant amount of β-sheets. This induces significant oxidative stress in vivo as observed for up to 60 min of peptide aggregation time. As the aggregation advances, the fibril-like aggregates become longer and intertwined, while the amount of β-sheets does not change significantly. An injection of such large, thick, and entangled aggregates in the animal brain results in a drastic increase in oxidative stress. This may be related to the number of activated microglia that initiate a sequence of inflammatory responses in the presence of large, highly interconnected fibrils.

MeSH terms

  • Amyloid beta-Peptides* / metabolism
  • Animals
  • Brain* / metabolism
  • Male
  • Mice
  • Oxidative Stress*
  • Peptide Fragments* / metabolism
  • Protein Aggregates
  • Protein Aggregation, Pathological / metabolism

Substances

  • Amyloid beta-Peptides
  • Peptide Fragments
  • Protein Aggregates
  • amyloid beta-protein (25-35)

Grants and funding

A.K. received financial support from DGAPA-UNAM (PAPIIT-IN100322); https://dgapa.unam.mx/index.php/impulso-a-la-investigacion/papiit; J.G. received financial support from the Faculty of Medicine of UNAM (3/2023); http://www.facmed.unam.mx/ The sponsors or funders did not play any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.