Real-time visualization of prion transport in single live cells using quantum dots

Area of Science:

• Neurobiology
• Cell Biology
• Biochemistry

Background:

• Prion diseases are fatal neurodegenerative conditions caused by misfolded prion proteins.
• The structural conversion of cellular PrP(C) to infectious PrP(Sc) is central to prion disease pathogenesis.
• It is hypothesized that prion structural conversion occurs during cellular internalization, but direct evidence is lacking.

Purpose of the Study:

• To directly visualize and characterize the real-time process of prion internalization in living cells.
• To investigate the role of cellular mechanisms, such as lipid rafts, in prion uptake.

Main Methods:

• Utilized quantum dots (QDs) as fluorescent probes to track prion internalization in real-time within living cells.
• Employed methyl-beta-cyclodextrin to disrupt cell membrane cholesterol and assess the involvement of lipid rafts.

Main Results:

• Provided the first real-time visualization of prion internalization, detailing four distinct stages of the process.
• Demonstrated that lipid rafts are essential for the initial localization of cellular PrP(C) to the cell membrane.
• Showed that lipid rafts are critical for initiating the endocytosis of PrP(C).

Conclusions:

• The study offers direct evidence supporting the hypothesis that prion structural conversion may occur during cellular internalization.
• Highlights the significant role of lipid rafts in mediating prion protein cell entry.
• Establishes a novel real-time imaging approach for studying prion dynamics in living cells.