α-Synuclein increases β-amyloid secretion by promoting β-/γ-secretase processing of APP

Hazel L. Roberts, Bernard L. Schneider, David R Brown

Research output: Contribution to journalArticlepeer-review

46 Citations (SciVal)

Abstract

a-Synuclein misfolding and aggregation is often accompanied by β-amyloid deposition in some neurodegenerative diseases. We hypothesised that α-synuclein promotes β-amyloid production from APP. β-Amyloid levels and APP amyloidogenic processing were investigated in neuronal cell lines stably overexpressing wildtype and mutant α-synuclein. γ-Secretase activity and β-secretase expression were also measured. We show that α-synuclein expression induces β-amyloid secretion and amyloidogenic processing of APP in neuronal cell lines. Certain mutations of α-synuclein potentiate APP amyloidogenic processing. γ-Secretase activity was not enhanced by wildtype α-synuclein expression, however β-secretase protein levels were induced. Furthermore, a correlation between α-synuclein and β-secretase protein was seen in rat brain striata. Iron chelation abolishes the effect of α-synuclein on neuronal cell β-amyloid secretion, whereas overexpression of the ferrireductase enzyme Steap3 is robustly pro-amyloidogenic. We propose that α-synuclein promotes β-amyloid formation by modulating β-cleavage of APP, and that this is potentially mediated by the levels of reduced iron and oxidative stress.

Original languageEnglish
Article numbere0171925
JournalPLoS ONE
Volume12
Issue number2
DOIs
Publication statusPublished - 1 Feb 2017

ASJC Scopus subject areas

  • General Medicine
  • General Biochemistry,Genetics and Molecular Biology
  • General Agricultural and Biological Sciences

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