Calpain-2 Regulates Kinesin and Dynein Dysfunction in Neurotoxin-Induced Motoneuron Injury

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Biology

Background:

• Neurodegenerative diseases like Parkinson's disease (PD) involve complex cellular dysfunctions.
• Efficient intracellular transport via kinesin and dynein motor proteins is crucial for neuronal health.
• Disruption of this transport system compromises neuronal function and survival.

Purpose of the Study:

• To investigate the role of kinesin and dynein in PD-associated intracellular transport defects.
• To explore the involvement of calpain-2 in motor protein dysfunction in PD models.
• To assess the therapeutic potential of calpain-2 inhibition for PD.

Main Methods:

• Utilized in vitro (MPP+-treated neuronal cells) and in vivo (MPTP-induced mouse model) PD models.
• Assessed motor protein function, vesicular trafficking, and endosome-lysosome recycling.
• Examined the effect of a selective calpain-2 inhibitor (zLLYCH2F) on transport mechanisms.

Main Results:

• MPP+ exposure disrupted kinesin- and dynein-mediated transport, impairing vesicular trafficking and endosome-lysosome recycling.
• Calpain-2 inhibition with zLLYCH2F restored motor protein function and normalized vesicle distribution.
• MPTP-treated mice showed reduced spinal cord dynein-positive fibers, a defect prevented by zLLYCH2F.

Conclusions:

• Calpain-2 activation contributes to motor protein dysfunction and impaired intracellular transport in PD.
• Inhibiting calpain-2 preserves motor protein stability and normalizes intracellular trafficking in PD models.
• Targeting calpain-2 presents a potential therapeutic avenue for Parkinson's disease.