Lysosomal TPC2 channels disrupt Ca2+ entry and dopaminergic function in models of LRRK2-Parkinson's disease

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Parkinson's disease (PD) is characterized by dopaminergic neuron loss in the midbrain.
• The precise molecular mechanisms driving this neurodegeneration remain incompletely understood.

Purpose of the Study:

• To investigate the interplay between calcium (Ca2+) influx and lysosomal function in dopaminergic neurons.
• To identify novel therapeutic targets for Parkinson's disease.

Main Methods:

• Utilized in vitro models to study Ca2+ entry and lysosomal cation release.
• Employed chemical and molecular inhibitors targeting the TPC2 ion channel.
• Investigated TPC2 function in Drosophila melanogaster models to assess in vivo effects.

Main Results:

• The LRRK2 G2019S mutation, common in PD, specifically enhanced Ca2+ entry.
• Inhibition of the lysosomal TPC2 channel reversed these detrimental Ca2+ changes.
• TPC2 expression in Drosophila recapitulated PD-associated behavioral deficits.
• A novel biased TPC2 agonist that reduces Ca2+ permeability ameliorated cellular and behavioral defects.

Conclusions:

• A functional link exists between lysosomal cation release and Ca2+ influx in maintaining dopaminergic neuron health.
• TPC2 plays a critical role in PD pathogenesis, with both inhibition and selective activation showing therapeutic potential.
• Targeting TPC2 represents a promising druggable strategy for Parkinson's disease treatment.