Unaltered SNARE complex formation in an in vivo model of prion disease

Area of Science:

• Neuroscience
• Prion Biology
• Molecular Neurodegeneration

Background:

• Prion diseases cause chronic neurodegeneration, characterized by synaptic dysfunction preceding neuronal death.
• Misfolded prion protein (PrPSc) accumulation is implicated in synaptic dysfunction.
• SNARE complexes, crucial for neurotransmitter release, are potentially inhibited by PrPSc.

Purpose of the Study:

• To investigate the impact of PrPSc deposition on SNARE complex integrity in the ME7 mouse model of prion disease.
• To determine if PrPSc disrupts SNARE complex formation in vivo, contributing to synaptic dysfunction.

Main Methods:

• Biochemical analysis of hippocampal tissue from the ME7 prion disease model.
• Detergent extraction (SDS and Triton X-100) to isolate SNARE complexes.
• SDS-PAGE to quantify SNARE complex levels.

Main Results:

• No change in directly SDS-extracted SNARE complexes with increasing PrPSc deposition.
• A modest reduction in Triton X-100 pre-extracted SNARE complexes at late stages of disease.
• PrPSc accumulation does not disrupt the formation of core SNARE complexes.

Conclusions:

• Accumulated PrPSc in the ME7 model does not inhibit the formation of essential SNARE complexes.
• The synaptic dysfunction observed in prion disease is not caused by PrPSc disrupting SNARE complex formation.
• PrPSc may inhibit ex vivo formed SNARE complexes, but not the in vivo essential machinery.