Evidence for aggregation-independent, PrP^C-mediated Aβ cellular internalization.

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Amyloid beta (Aβ) cellular uptake is linked to toxicity, but mechanisms remain unclear.
• Key questions involve Aβ aggregation dependence and sequence specificity in uptake.
• Cellular prion protein (PrP^C) is implicated in Aβ toxicity and neuronal internalization.

Purpose of the Study:

• To investigate if Aβ uptake is aggregation-dependent and sequence-specific.
• To determine the role of PrP^C in stereoselective Aβ internalization.
• To identify the molecular interactions between Aβ and PrP^C.

Main Methods:

• Utilized a soluble, nonfibrillizing Aβ (1-30) peptide to decouple aggregation from internalization.
• Assessed Aβ (1-30) uptake dependence on PrP^C expression.
• Employed NMR spectroscopy for molecular-level characterization of Aβ-PrP^C interactions.

Main Results:

• Aβ (1-30) peptide demonstrated stereoselective cellular uptake, independent of aggregation.
• Aβ (1-30) uptake was dependent on PrP^C expression.
• NMR identified the PrP^C docking site for stereoselective Aβ (1-30) binding, revealing a specific recognition sequence.

Conclusions:

• Aβ cellular uptake is stereoselective and mediated by specific sequences and receptors like PrP^C.
• PrP^C recognizes a specific Aβ sequence, facilitating PrP^C-dependent cellular uptake.
• Additional receptor interactions contribute to Aβ internalization; targeting surface receptors is a potential therapeutic strategy for Alzheimer's disease.