Extracellular microvesicles-derived from microglia treated with unaggregated α-synuclein attenuate mitochondrial fission and toxicity-induced by Parkinsonian toxin MPP+

Biological functions of extracellular vesicles (EVs) are being discovered to be critical in neurodegenerative disorders, including Parkinson's disease (PD). A previous study using cellular models of PD has suggested that EVs derived from microglia exposed to aggregated α-synuclein (α-Syn) leads to enhanced neurotoxicity. However, the function of EVs derived from microglia not treated with aggregated a-Syn or treated with monomeric α-Syn are unclear. Here, employing a widely used cellular model of PD, i.e. SH-SY5Y cells treated with MPP+, a well-established parkinsonian toxicant, we revealed that microglial EVs, when not stimulated by aggregated α-Syn, appeared to be protective, and the mechanisms, though remain to be defined further, appeared to involve mitochondrial dynamics, especially mitochondrial fission.