ABSTRACT:
Parkinson's disease (PD) is a neurodegenerative disease characterized by dopaminergic neuronal degeneration in the substantia nigra, in which lysosomal dysfunction and impaired autophagy–lysosome pathway activity are increasingly recognized as important pathogenic mechanisms. However, disease‐modifying therapies targeting this pathway remain unavailable. Here, we generated induced pluripotent stem cells (iPSCs) from a PARK9 patient carrying an
ATP13A2
mutation and established mutation‐corrected isogenic control iPSCs. PARK9 iPSC‐derived neurons recapitulated lysosomal dysfunction–associated cellular phenotypes, including impaired lysosomal acidification, reduced mature cathepsin D levels, CD63‐positive vesicle accumulation, LC3B‐positive autophagosome accumulation, cytoplasmic pSer129 α‐synuclein accumulation, and increased cleaved caspase‐3 signals. These phenotypes were ameliorated in mutation‐corrected neurons, supporting the contribution of ATP13A2 dysfunction to these abnormalities. We then performed high‐content imaging–based compound screening targeting LC3B‐positive autophagosome accumulation in PARK9 neurons. A three‐step workflow identified 19 candidate compounds that reduced autophagosome accumulation consistent with partial improvement of lysosome‐dependent downstream autophagosome processing rather than simple suppression of autophagosome formation. Among these, paroxetine, Ro 25‐6981, amisulpride, and PK11195 showed additional, compound‐dependent effects on PARK9‐associated phenotypes, including lysosomal acidification, CD63‐positive vesicle accumulation, cytoplasmic pSer129 α‐synuclein signals, and cleaved caspase‐3 signals. These findings establish PARK9 iPSC‐derived neurons as a useful model of lysosomal dysfunction–associated PD pathology and provide a practical screening platform for identifying candidate compounds that modulate autophagy–lysosome pathway‐related cellular phenotypes.
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