ScholarWorks@중앙대학교

초록

Recent evidence suggests a potential link between airborne microplastics (MP) and nanoplastics (NP) and neurodegenerative diseases, yet direct in vivo demonstration of their neurotoxicity remains limited. This study aimed to assess the potential risk of Parkinson's disease (PD) associated with chronic inhalation exposure to polystyrene nanoplastics (PS-NP), by examining PD-relevant behavioral and neuropathological alterations compared to polystyrene microplastics (PS-MP). Adult mice were exposed daily to 100 ppm/200 mu L of 20 nm PSNP or 0.25 mu m PS-MP via inhalation for 16 weeks. Brain uptake and exposed dose were quantified using 64Culabeled PS and gamma counting. Behavioral assessments, histology, immunohistochemistry, western blotting, and RNA sequencing were performed to evaluate PD-relevant outcomes. Only 0.094 % of the estimated humanequivalent environmental dose was exposed to the substantia nigra and striatum. PS-NP exposure induced greater behavioral deficits compared to PS-MP. RNA-seq revealed dysregulation of PD-related genes, overlapping with those in MPTP-induced PD models. Western blot and immunohistochemistry confirmed reduced tyrosine hydroxylase, increased phospho-alpha-synuclein (Ser129) aggregation, and elevated markers of glial activation (GFAP, IBA1) and pro-inflammatory cytokines in the PS-NP group. Inhaled PS-NP induced PD-relevant neuropathological and behavioral changes, suggesting that chronic exposure may contribute to increased PD risk under environmentally realistic conditions. These findings emphasize the need to evaluate airborne NP exposure as a novel environmental risk factor for PD.

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