The role of p.D620N VPS35 patient-derived microglia in Parkinson’s Disease pathophysiology

Parkinson’s Disease (PD) is the second most common neurodegenerative disease. One of the genes that is strongly related with PD is VPS35. VPS35, is involved in the intracellular trafficking of the proteins and our group has confirmed that the D620N VPS35 mutation, in patient iPSC-derived dopaminergic neurons (DN), is associated with increased α-synuclein levels due to decrease autophagic flux and significant mitochondrial dysfunction. Recently, another study links VPS35 KO with suppressing microglia polarization, with subsequent accumulation of neurotoxic pro-inflammatory microglia, in ischemic stroke-induced injury mouse model.
Our project proposal is the identification of the role of D620N VPS35 mutation in patient iPSC-derived microglia’s metabolism, the role in PD’s pathophysiology, the confirmation of the mechanism of action and the proposal of a putative co-treatment, based on our results. For this reason, D620N VPS35 mutated iPSCs will be differentiated into functional microglia, in order to characterize the microglial phenotype (cell viability, cytokines production, metabolite quantification/secretosome, phagocytosis efficiency-response to α-synuclein aggregation, mitochondrial/lysosomal function, transcriptomic analysis and exosomal studies), D620N VPS35 mutated iPSC-derived microglia will be co-culture with DN, in order to identify the alterations in the phenotype/metabolism of both cell types, the signaling interaction and the impact of the exosomes in each cell type. Finally, based on our findings, there will be identified new ‘’signature’’- pathways-molecules, that will serve as targets for an innovative co-treatment against PD and their efficiency will be evaluated based on the phenotypic studies (mentioned above).