The LRRK2 kinase substrates Rab8a and Rab10 contribute complementary but distinct disease-relevant phenotypes in...

Area of Science:

• Neuroscience
• Genetics
• Cell Biology

Background:

• Mutations in the Leucine-Rich Repeat Kinase 2 (LRRK2) gene are a significant cause of familial Parkinson's disease.
• Pathogenic LRRK2 mutations are associated with increased kinase activity, impacting cellular processes.
• LRRK2 substrates, including Rab GTPases like Rab8a and Rab10, are implicated in neurodegenerative pathways.

Approach:

• CRISPR/Cas9 genome editing was employed to create isogenic induced pluripotent stem cell (iPSC) lines lacking functional Rab8a and Rab10.
• These engineered cell lines were differentiated into NGN2-induced neurons for detailed cellular analysis.
• Two independent, well-characterized healthy control lines were used to ensure reproducibility.

Key Points:

• Rab8a and Rab10 deficiency exhibited divergent impacts on neuronal lysosomal pH, alpha-synuclein insolubility, and tau phosphorylation.
• Both Rab8a and Rab10 inactivation led to parallel alterations in lysosomal number and Golgi clustering.
• The study highlights largely antagonistic effects between Rab8a and Rab10 inactivation.

Conclusions:

• Genetic inactivation of Rab8a or Rab10 in neurons provides discrete insights into Parkinson's disease pathology linked to LRRK2.
• These findings suggest distinct roles for Rab8a and Rab10 in cellular homeostasis relevant to LRRK2 neuropathology.
• Understanding these divergent effects is crucial for deciphering the complex mechanisms of LRRK2-driven neurodegeneration.