Department of Neurology, Clinical Neuroscience Branch, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.
Department of System Pathology for Neurological Disorders, Brain Science Branch, Center for Bioresource-based Research, Brain Research Institute, Niigata University, Niigata 951-8585, Japan.
Neurobiol Dis. 2019 Oct;130:104534. doi: 10.1016/j.nbd.2019.104534. Epub 2019 Jul 13.
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by accumulation of fragmented insoluble TDP-43 and loss of TDP-43 from the nucleus. Increased expression of exogenous TARDBP (encoding TDP-43) induces TDP-43 pathology and cytotoxicity, suggesting the involvement of aberrant expression of TDP-43 in the pathogenesis of ALS. In normal conditions, however, the amount of TDP-43 is tightly regulated by the autoregulatory mechanism involving alternative splicing of TARDBP mRNA. To investigate the influence of autoregulation dysfunction, we inhibited the splicing of cryptic intron 6 using antisense oligonucleotides in vivo. This inhibition doubled the Tardbp mRNA expression, increased the fragmented insoluble TDP-43, and reduced the number of motor neurons in the mouse spinal cord. In human induced pluripotent stem cell-derived neurons, the splicing inhibition of intron 6 increased TARDBP mRNA and decreased nuclear TDP-43. These non-genetically modified models exhibiting rise in the TARDBP mRNA levels suggest that TDP-43 autoregulation turbulence might be linked to the pathogenesis of ALS.
肌萎缩性侧索硬化症（ALS）是一种神经退行性疾病，其特征是 TDP-43 碎片的不溶性积累和 TDP-43 从核内丢失。外源性 TARDBP（编码 TDP-43）的表达增加会诱导 TDP-43 病理学和细胞毒性，表明 TDP-43 的异常表达参与了 ALS 的发病机制。然而，在正常情况下，TDP-43 的量受到涉及 TARDBP mRNA 可变剪接的自动调节机制的严格调节。为了研究自动调节功能障碍的影响，我们在体内使用反义寡核苷酸抑制隐匿内含子 6 的剪接。这种抑制使 Tardbp mRNA 的表达增加了一倍，增加了不溶性的断裂 TDP-43，并减少了小鼠脊髓中的运动神经元数量。在人诱导多能干细胞衍生的神经元中，内含子 6 的剪接抑制增加了 TARDBP mRNA 并减少了核内 TDP-43。这些非基因修饰模型中 TARDBP mRNA 水平的升高表明，TDP-43 的自动调节紊乱可能与 ALS 的发病机制有关。
