2023 Fiscal Year Final Research Report

In vitro model of NEDAMSS pathology using patients-derived iPS cells with sporadic IRF2BPL mutation

Research Project

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Project/Area Number	20K07763
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 51030:Pathophysiologic neuroscience-related
Research Institution	Dokkyo Medical University
Principal Investigator	Inoue Kenichi 獨協医科大学, 医学部, 准教授 (90587974)
Co-Investigator(Kenkyū-buntansha)	相馬良一獨協医科大学, 医学部, 助教 (20868054) 中舘和彦明治薬科大学, 薬学部, 教授 (80372895) 山内忍獨協医科大学, 医学部, 助教 (70433589)
Project Period (FY)	2020-04-01 – 2024-03-31
Keywords	IRF2BPL / NEDAMSS / 患者由来iPS細胞 / 皮質ニューロン / アストログリア / lamellar body / multivesicular body
Outline of Final Research Achievements	Here we established in vitro disease model for a newly identified pediatric disease, NEDAMSS. We used iPS cells from two NEDAMSS patients with the identical IRF2BPL mutation. Dual SMAD inhibition successfully differentiated iPS cells into cortical neurons and astrocytes. Co-cultures of neurons and astrocytes were analyzed using electron microscopy. In neurons derived from patients, numerous autophagy-like bodies were observed. These autophagy-like bodies displayed various forms, ranging from lamellar bodies and multivesicular bodies to vacuoles formed by advanced autophagic digestion. Such structures were not observed in neurons from healthy sibling controls cultured for the same period, suggesting that the patient neurons exhibit lipid metabolism abnormalities and are in the process of neurodegeneration.
Free Research Field	神経病態学
Academic Significance and Societal Importance of the Research Achievements	NEDAMSSは、致死性の小児神経変性疾患である。NEDAMSSの責任遺伝子として、IRF2BPLの孤発性点突然変異が同定された。ところが飜訳された変異タンパクの機能や責任病変は、殆ど分かっていなかった。本研究は世界ではじめてNEDAMSS患者由来iPS細胞を２症例樹立し、病態モデルを確立した。電子顕微鏡観察では患者由来ニューロンの神経変性様表現型（オートファゴソーム過剰活動、脂質代謝異常）が再現され、目標の一部を達成した。また正常型・変異型のIRF2BPLタンパク質の結合タンパクを複数（PKM, IRF2BP1, BP2, BPL）同定したため、引き続き病態メカニズムを追究していく。