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Kazuaki KANAI4), Hideyuki OKANO5), Nobutaka HATTORI2), Wado AKAMATSU1)3)National Hospital Oaganization Chiba-East-Hospital, Chiba, Japan2)Department of Neurology, Juntendo University, School of Medicine, Tokyo, Japan5)Department of Physiology, Keio University Graduate School of Medicine, Tokyo, Japan4)Department of Neurology, Fukushima Medical University, School of Medicine, Fukushima, Japan1)Center for Genomic and Regenerative Medicine, Juntendo University Graduate School of Medicine, Tokyo, JapanKeiichi TSUKIBOSHI1), Akihiro YAMAGUCHI1), Kei-ichi ISHIKAWA1, 2), Kimihito ARAI3), iPSC-based Drug Screening for PARK9, a Familial Parkinson’s Disease with Impaired AutophagyCorresponding author: Kei-ichi IshikawaCenter for Genomic and Regenerative Medicine, Juntendo University Graduate School of Medicine2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421TEL: +81-3-5802-1073　FAX: +81-3-5684-0476　E-mail: kishikaw@juntendo.ac.jpResearch of the 3rd Alumni Scientific Award for Medical Student, Juntendo University School of Medicine〔Received　Oct. 21, 2020〕〔Accepted　Aug. 10, 2021〕J-STAGE Advance published date: Oct. 25, 2021Copyright © 2021 The Juntendo Medical Society. This is an open access article distributed under the terms of Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original source is properly credited. doi: 10.14789/jmj.JMJ20-A02　Parkinson's disease (PD) is a neurodegenerative disorder with the degeneration of midbrain dopaminergic neurons. However, few disease-modifying drugs for patients with PD have been identified. Familial Parkinson's diseases are numbered in the order in which the causative genes are identified, and one of them, PARK9, is caused by autophagy dysfunction and has mutation in the ATP13A2 gene which encodes a lysosomal type 5 P-type ATPase. To elucidate the pathogenesis and to screen effective drugs for PARK9, we generated iPSCs from the T cells from a PARK9 patient. Three independent clones were used for the analysis after quality verification. First, we confirmed reduced autophagy function in dopaminergic neurons derived from PARK9 iPSCs by examining the accumulation of LC3B, an autophagosome marker, due to impaired lysosomal functions. Then, we successfully quantified LC3B accumulation in the cell bodies of PARK9 dopaminergic neurons using IN Cell Analyzer 2200. Using these methods, we screened a compound library containing 320 chemical compounds using reduced LC3B accumulation in PARK9 dopaminergic neurons as an indicator. The first screening narrowed the list of candidate compounds to 70, followed by the second screening to exclude the compounds that reduce LC3B production. This two-step and 96 well-based high-throughput screening resulted in the identification of five novel disease modifying drug candidates that ameliorate impaired lysosomal dysfunction in PARK9-dopaminergic neurons.450Juntendo Medical Journal2021. 67(5), 450Key words: Parkinson’s disease, iPSCs, lysosome, autophagy, drug screeningReviews