Two-step screening method to identify α-synuclein aggregation inhibitors for Parkinson’s disease
Makoto Hideshima, Yasuyoshi Kimura, César Aguirre, Keita Kakuda, Toshihide Takeuchi, Chi‐Jing Choong, Junko Doi, Kei Nabekura, K. Yamaguchi, Kichitaro Nakajima, Kousuke Baba, Seiichi Nagano, Yuji Goto, Yoshitaka Nagai, Hideki Mochizuki, Kensuke Ikenaka
Abstract
Parkinson's disease is a neurodegenerative disease characterized by the formation of neuronal inclusions of α-synuclein in patient brains. As the disease progresses, toxic α-synuclein aggregates transmit throughout the nervous system. No effective disease-modifying therapy has been established, and preventing α-synuclein aggregation is thought to be one of the most promising approaches to ameliorate the disease. In this study, we performed a two-step screening using the thioflavin T assay and a cell-based assay to identify α-synuclein aggregation inhibitors. The first screening, thioflavin T assay, allowed the identification of 30 molecules, among a total of 1262 FDA-approved small compounds, which showed inhibitory effects on α-synuclein fibrilization. In the second screening, a cell-based aggregation assay, seven out of these 30 candidates were found to prevent α-synuclein aggregation without causing substantial toxicity. Of the seven final candidates, tannic acid was the most promising compound. The robustness of our screening method was validated by a primary neuronal cell model and a Caenorhabditis elegans model, which demonstrated the effect of tannic acid against α-synuclein aggregation. In conclusion, our two-step screening system is a powerful method for the identification of α-synuclein aggregation inhibitors, and tannic acid is a promising candidate as a disease-modifying drug for Parkinson's disease.