LRRK2 I1371V Impairs Astrocytic Glucose Metabolism and Triggers Multi-Organellar Dysfunction in PD

Abstract

While LRRK2 mutations modulate systemic glucose homeostasis and metabolic dysfunction precedes Parkinsons disease (PD) motor-symptoms, the impact of pathogenic LRRK2-mutations on astrocytic glucose-uptake and organellar function remains unexplored. Here, we demonstrate that LRRK2-I1371V mutation causes profound metabolic and organellar dysfunction in LRRK2-I1371V PD-iPSC-derived astrocytes and U87 cells overexpressing I1371V variant. LRRK2-I1371V astrocytes exhibit significantly reduced GLUT1 expression and plasma membrane localization, resulting in impaired glucose-uptake and decreased lactate-production. This metabolic insufficiency correlates with cascading mitochondrial dysfunction, characterized by membrane depolarization, elevated reactive-oxygen-species, enhanced ubiquitination and reduced proteasomal-activity. Reduced LAMP1/LAMP2 expression, impaired lysosomal-acidification, and selective cathepsin D deficiency were observed. Accumulation of undegraded cargo was confirmed by transmission-electron-microscopy upon -synuclein exposure. ER stress was evident through upregulated GADD34/CHOP, increased phospho-PERK, and reduced nascent protein synthesis. Our results reveal that LRRK2-I1371V induces glucose-uptake deficits, causing energy depletion and multi-organellar dysfunction, identifying astrocytic metabolic restoration as a promising therapeutic target for I1371V-associated PD.