ALSの原因タンパク質TDP-43の新たな機能を発見

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2026-02-24 名古屋大学

名古屋大学大学院医学系研究科神経内科学の勝野雅央教授、井口洋平講師らは、ALS原因タンパク質TDP-43の新機能を解明した。ニューロン特異的TDP-43欠損マウスでは軸索の髄鞘化が著減し、短期記憶障害も出現。解析の結果、TDP-43はニューレキシン1 mRNAを安定化し、その発現調節を介して髄鞘形成を促進することを明らかにした。海馬でニューレキシン1を補充すると記憶障害は改善し、ALS患者剖検脳でも同分子の低下を確認。TDP-43機能喪失が低髄鞘化を招く新機序を示し、病態抑止療法への応用が期待される。成果はProceedings of the National Academy of Sciencesに掲載予定。

ALSの原因タンパク質TDP-43の新たな機能を発見

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神経細胞のTDP-43はニューレキシン1 mRNAの安定化を介してミエリン形成を制御する Neuronal TDP-43 regulates myelin formation via neurexin 1 mRNA stabilization

Jiayi Li, Yohei Iguchi, Kenji Yoshida, +16 , and Masahisa Katsuno
Proceedings of the National Academy of Sciences  Published:February 25, 2026

Significance

TAR DNA-binding protein 43 (TDP-43) is a major component of the pathological inclusion of neurons of Amyotrophic lateral sclerosis and frontotemporal lobar degeneration, and dysfunction of TDP-43 has been thought to be a major cause of these diseases. This study demonstrates that loss of TDP-43 in neurons induces hypomyelination, and this impairment was rescued with the supplementation of cytoplasmic TDP-43 in neurons. Using fluorescence-activated cell sorting and RNA sequencing, we identified NRXN1 as the factor which promotes myelin formation and is regulated by TDP-43. Supplementation of NRXN1 in the neurons restored the hypomyelination in TDP-43cKO mice. These findings suggest the pivotal roles of neuronal TDP-43 in neuron–oligodendrocyte interactions.

Abstract

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) develop as spatial pathologies in which neurons and glial cells are interconnected. TAR DNA-binding protein 43 (TDP-43) is a major pathological protein that is inextricably associated with ALS and FTLD. In this study, we investigated the roles of neuronal TDP-43 in neuron–oligodendrocyte interactions using neuron-specific TDP-43 knockout (TDP-43cKO) mice. TDP-43 depletion in neurons induced hypomyelination, which was confirmed by immunohistochemistry and ultrastructural analysis. In addition, conduction disturbance was revealed by electrophysiological analysis. The hypomyelination of TDP-43cKO mouse was restored by cytoplasmic TDP-43 supplementation in neurons. Neuron-specific transcriptome analysis revealed that neurexin 1 (NRXN1) is the regulatory target of TDP-43, which promotes myelin formation. The hypomyelination of TDP-43cKO mice was also restored by NRXN1b supplementation in neurons. We further confirmed that TDP-43 stabilizes Nrxn1 mRNA by binding to the Nrxn1 3’untranslated region (3’UTR). Although TDP-43cKO exhibited impaired recognition memory, the supplementation of NRXN1 in the hippocampus recovered the memory disturbances. In conclusion, this study demonstrates the neuron–oligodendrocyte interaction mediated by neuronal TDP-43 via NRXN1 mRNA stabilization. These findings shed light on neuron–oligodendrocyte interaction in the disease mechanisms of ALS/FTLD.

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