Modeling Parkinson's disease in LRRK2 rodents.

Area of Science:

• Neuroscience
• Genetics
• Pathology

Background:

• Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are a significant cause of familial and sporadic Parkinson's disease (PD).
• LRRK2-associated PD shares clinical and neuropathological hallmarks with sporadic PD, including motor deficits and Lewy body formation.
• Rodent models with common LRRK2 mutations (p.G2019S, p.R1441C/G) were developed to study Parkinson's disease pathogenesis.

Purpose of the Study:

• To investigate the phenotype of LRRK2 rodent models harboring common PD-associated mutations.
• To explore the utility of LRRK2 rodents in understanding the pathogenic mechanisms of Parkinson's disease.
• To examine the role of LRRK2 mutations in modulating susceptibility to environmental risk factors in PD.

Main Methods:

• Generation of rodent models with specific LRRK2 mutations (p.G2019S, p.R1441C/G).
• Phenotypic characterization of LRRK2 rodents, including motor and non-motor assessments.
• Evaluation of LRRK2 rodent susceptibility to neurotoxic insults using dual-hit or multiple-hit protocols.

Main Results:

• LRRK2 rodents did not consistently replicate cardinal PD motor symptoms or Lewy body pathology.
• These models exhibited non-motor signs and altered dopaminergic/non-dopaminergic synaptic transmission, mirroring prodromal PD changes.
• LRRK2 rodents showed increased vulnerability to parkinsonian toxins, supporting LRRK2 mutations as genetic risk factors.

Conclusions:

• LRRK2 rodents offer a valuable model for studying early-stage Parkinson's disease and non-motor symptoms.
• These models are instrumental in elucidating LRRK2's role in modulating PD pathogenesis and risk factor interplay.
• LRRK2 rodents provide a platform for identifying molecular mechanisms underlying LRRK2-associated Parkinson's disease.