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Updated: Aug 9, 2025
Optogenetic Phase Transition of TDP-43 in Spinal Motor Neurons of Zebrafish Larvae
Published on: February 25, 2022
Pathological Comparison of TDP-43 Between Motor Neurons and Interneurons Expressed by a Tetracycline Repressor System
Shota Togai1, Shusei Hamamichi2, Yasuhiro Kazuki1,2,3,4
1Department of Chromosome Biomedical Engineering, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Sciences, Tottori University, Yonago 683-8503, Japan.
Background:
Cytoplasmic mislocalization of TAR-DNA binding protein of 43 kDa (TDP-43) is a major hallmark of amyotrophic lateral sclerosis (ALS). TDP-43 aggregation is detected in the cortical and spinal motor neurons in most ALS cases; however, pathological mechanism of this mislocalized TDP-43 remains unknown.
Methods:
We generated a tetracycline-inducible TDP-43 A315T system on a mouse artificial chromosome (MAC) vector to avoid transgene-insertional mutagenesis, established a mouse embryonic stem (ES) cell line holding this MAC vector system, and investigated whether overexpressed exogenous TDP-43 A315T was mislocalized in the cytoplasm of the ES cell-derived neurons and triggered the neurotoxic effects on these cells.
Results:
Inducible TDP-43 A315T system was successfully loaded onto the MAC and introduced into the mouse ES cells. These ES cells could differentiate into motor neurons and interneurons. Overexpression of TDP-43 A315T by addition of doxycycline in both neurons resulted in mislocalization to cytoplasm. Mislocalized TDP-43 caused cell death of motor neurons, but not interneurons.
Conclusion:
Vulnerability to cytoplasmic mislocalized TDP-43 is selective on neuronal types, whereas mislocalization of overexpressed TDP-43 occurs in even insusceptible neurons. This inducible gene expression system using MAC remains useful for providing critical insights into appearance of TDP-43 pathology.
