Dysregulation of Extracellular Vesicle Concentration, MicroRNAs, and Surface Proteins in Patients With Niemann-Pick Disease Type C.

Niemann-Pick disease type C (NPC) is a rare neurodegenerative disease primarily caused by mutations in the NPC1 gene, which is associated with cholesterol trafficking impairment, and disruption of endolysosomal processing and extracellular vesicles (EVs). Here, for patients with NPC1 mutations (NPC) and age-matched controls (CTL) we describe the EV profile of dermal fibroblasts (n = 5 NPC, n = 3 CTL) and, for the first time, cerebrospinal fluid (CSF, n = 5 NPC, n = 5 CTL). EVs were enriched using size-exclusion chromatography and characterized by immunoblot, transmission electron microscopy, and microchip resistive pulse sensing. Single vesicle flow cytometry showed increased EV concentration in NPC CSF versus CTLs. In fibroblasts, EV concentration inversely correlated with NPC1 protein levels that was partially attenuated by hydroxypropyl-β-cyclodextrin, an experimental NPC therapeutic. Direct stochastic imaging and multiplexed EV immunoassays revealed that NPC EVs were enriched for endolysosomal proteins (CD63, Lamp1). Three miRNAs (miR-365-3p, -654-3p, -598-3p) were increased in NPC fibroblast EVs and two (miR-320a, -199a/b-3p) in NPC CSF EVs. Pathway analysis using those miRNAs identified relevant diseases and functions (cell death and survival, molecular transport, heredity neurological disease). These results demonstrate that NPC1 gene mutations alter EV biogenesis and disease-associated changes in cargo that may serve as clinical biomarkers or therapeutic targets for NPC, a devastating disease without a cure.