Apolipoprotein E impairs amyloid-β fibril elongation and maturation

Area of Science:

• Neuroscience
• Biochemistry
• Molecular Biology

Background:

• Alzheimer's disease (AD) is characterized by amyloid-beta (Aβ) peptide depositions.
• Apolipoprotein E (ApoE) influences Aβ amyloid formation and AD pathology.
• APOE ε4 allele carriers have an increased risk for developing AD.

Purpose of the Study:

• To investigate the mechanism by which ApoE interferes with Aβ amyloid formation.
• To determine how ApoE affects Aβ fibril elongation and maturation.

Main Methods:

• Surface plasmon resonance (SPR) assays.
• Thioflavin-T (ThT) fluorescence assays.

Main Results:

• ApoE directly targets the elongation phase of Aβ fibril formation.
• ApoE interference effectively prevents the maturation of Aβ amyloids.
• A complex equilibrium involving ApoE, Aβ monomers, and existing fibrils dictates amyloid formation rates and alternative assembly production.

Conclusions:

• ApoE acts as a potent inhibitor of Aβ amyloid fibril elongation.
• The findings elucidate a novel mechanism influencing Aβ assembly dynamics in vivo.
• This mechanism may affect both the clearance of Aβ aggregates and the formation of cytotoxic species.