Parkinson's associated protein DJ-1 regulates intercellular communication via extracellular vesicles in oxidative stress.

Mutations in DJ-1 cause autosomal recessive Parkinson's disease (PD). Several functions have been attributed to DJ-1, including a key role in the protection from oxidative stress. However, how this protein contributes to PD pathogenesis is still unclear. Recently, DJ-1 has been identified at higher concentrations in extracellular vesicles (EV) from biological fluids of PD patients, providing a link between EV and a protein associated with PD. In this study, EV were purified from the medium of control and rotenone-treated wild-type and DJ-1 KO differentiated SH-SY5Y cells. EV quantity was assessed using flow cytometry, and their proteomic cargo was analysed via mass spectrometry. We identified an altered EV response to rotenone in DJ-1 KO cells compared to wild-type. Mass spectrometry analysis identified 116 proteins with significantly altered abundance between the two genotypes, indicating a role for DJ-1 in modulating EV cargo under oxidative stress conditions. Label-free identification of oxidative modifications indicated that DJ-1 clearly influences the oxidative profile of EV proteins. Additionally, we showed that DJ-1 KO alters the ability of the secretome to stimulate macrophage migration, suggesting functional consequences of DJ-1 deficiency in secretome-mediated responses to oxidative stress. The altered EV response to rotenone was confirmed in iPSC-derived neurons lacking DJ-1 compared to isogenic controls. Our results reveal a distinct role for DJ-1 in regulating intercellular communication under oxidative stress, highlighting a novel EV-mediated function of DJ-1 that may contribute to Parkinson's disease pathogenesis.