LRRK2 modifies α-syn pathology and spread in mouse models and human neurons

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• Parkinson's disease (PD) is characterized by alpha-synuclein (α-syn) aggregation and dopaminergic neuron loss.
• α-syn pathology is believed to propagate through neuronal circuits, driving disease progression.
• Identifying genetic modifiers of α-syn transmission is crucial for developing effective PD therapies.

Purpose of the Study:

• To investigate the role of Parkinson's disease risk genes in modulating α-syn aggregation and transmission.
• To explore the therapeutic potential of targeting LRRK2 (Leucine-rich repeat kinase 2) in Parkinson's disease.

Main Methods:

• Performed a genetic screen of PD risk genes using an α-syn preformed-fibril (PFF) induction assay in mouse primary neurons.
• Utilized LRRK2 G2019S transgenic mice to study α-syn aggregation and neurodegeneration in vivo.
• Developed a human α-syn transmission model using induced pluripotent stem cell (iPS)-derived neurons (iNs).

Main Results:

• Decreased Lrrk2 and Gba expression modulated α-syn aggregation in mouse neurons.
• The LRRK2 G2019S mutation accelerated α-syn aggregation, dopaminergic neurodegeneration, and neuroinflammation in mice.
• In human iNs, the G2019S mutation enhanced α-syn aggregation, while LRRK2 loss reduced it.

Conclusions:

• Established a significant interaction between the PD risk gene LRRK2 and α-syn transmission in both mouse and human models.
• Suggests that LRRK2 inhibitors, currently in clinical trials, could be a broadly effective therapeutic strategy for Parkinson's disease.