著者

漆谷 真

出版者

日本神経治療学会

雑誌

神経治療学 (ISSN:09168443)

巻号頁・発行日

vol.34, no.2, pp.72-78, 2017 (Released:2017-07-25)

参考文献数

32

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TAR DNA–binding protein 43kDa (TDP–43) is a hallmark protein for amyotrophic lateral sclerosis (ALS), consisting of ubiquitinated and phosphorylated cytosolic inclusions in affected regions, namely TDP–43 proteinopathy. TDP–43 is physiologically located in the nucleus and plays diverse roles to maintain the RNA homeostasis, including pro–mRNA splicing, microRNA processing, non–coding RNA stabilization, mRNA transport, and the stress granule formation. Multiple cascades, basically causing a loss of these functions, have been proposed as TDP–43–linked ALS pathogenesis ; however, the mislocalization and aggregate formation of TDP–43 is considered to underlie various pathogenic pathways, ultimately leading to motor neuron death. A cell–to–cell spreading theory is attracting huge attention to explain the rapid regional progression of the paralysis, although in vivo evidence is still lacking. Recent knowledge highlights the stress granules as responsible sites of TDP–43 inclusion formation. The stress granules contain mRNA with chains of ribosomes, together with stress granule–related proteins, such as TIA1 and TDP–43, in which RNA translation is inhibited transiently until stress conditions are recovered. The disruption of this reversibility is implicated in the irreversible inclusion formation. A proportion of familial ALS patients carries genetic mutations in the TDP–43 gene, the most of which are concentrated at the carboxyl prion–like domain. Although the pathomechanisms regarding how mutant TDP–43 causes ALS remain elusive, it is reported that mutant TDP–43 impairs proteasome activity, resulting in the accumulation of aberrant TDP–43. Moreover, several genetic mutations other than TDP–43, such as C9ORF72, MATR3, hnRNP1, UBQLN2, STSM1, VCP, and OPTN cause TDP–43 proteinopathy. Importantly, transgenic mice expressing cytosolic TDP–43 show the similar phenotype of ALS, and the inhibition of the transgene restore the paralysis of the mice. These line of evidence indicate the huge potential of misfolded TDP–43 as a therapeutic target. Capturing the early structural conversion to pathogenic forms is a promising therapeutic avenue to overcome ALS.

著者

漆谷 真 守村 敏史

出版者

滋賀医科大学

雑誌

基盤研究(B)

巻号頁・発行日

2014-04-01

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我々は以前に筋萎縮性側索硬化症の原因蛋白質であるTDP-43の2つのRNA認識部位(RRM1とRRM2)内の配列を抗原とし、異所性局在型や凝集体形成型のTDP-43のみを認識する抗体を作出した。本研究ではこれらの抗体を用いて、TDP-43凝集体の形成を阻止する低分子化合物の同定や一本鎖抗体(scFv)を作製し細胞内のTDP-43凝集体の除去効果を検証した。RRM1抗体を用いた競合ELISA法によってTDP-43の異常会合界面に結合し凝集体形成を阻止する化合物を同定した。RRM2を抗原とし蛋白質分解シグナルを持つscFvはTDP-43凝集体と特異的に結合し分解促進し細胞死を抑える成果が得られた。