Modeling Lewy Body Disease with SNCA Triplication Ipsc-Derived Cortical Organoids and Identifying Therapeutic Drugs

Aggregated alpha-synuclein (alpha-SYN) proteins, encoded by the SNCA gene, are hallmarks of Lewy body disease (LBD), affecting multiple brain regions. However, the specific mechanisms underlying alpha-SYN pathology in cortical neurons, crucial for LBD-associated dementia, remain unclear. Here, we recapitulated alpha-SYN pathologies in human induced pluripotent stem cells (iPSCs)-derived cortical organoids generated from patients with LBD with SNCA gene triplication. Single-cell RNA sequencing, combined with functional and molecular validation, identified synaptic and mitochondrial dysfunction in excitatory neurons exhibiting high expression of the SNCA gene, aligning with observations in the cortex of autopsy-confirmed LBD human brains. Furthermore, we screened 1280 Food and Drug Administration-approved drugs and identified four candidates (entacapone, tolcapone, phenazopyridine hydrochloride, and zalcitabine) that inhibited alpha-SYN seeding activity in real-time quaking-induced conversion assays with human brains, reduced alpha-SYN aggregation, and alleviated mitochondrial dysfunction in SNCA triplication organoids and excitatory neurons. Our findings establish human cortical LBD models and suggest potential therapeutic drugs targeting alpha-SYN aggregation for LBD.