Gain and loss of function of ALS-related mutations of TARDBP (TDP-43) cause motor deficits in vivo
Gain and loss of function of ALS-related mutations of TARDBP (TDP-43) cause motor deficits in vivo
复制标题
DOI：
10.1093/hmg/ddp534
复制
发表时间：
2010-02-15
影响因子：
3.5
通讯作者：
Drapeau, Pierre
中科院分区：
文献类型：
--
作者：
Kabashi, Edor;Lin, Li;Drapeau, Pierre
TDP-43已在多种神经系统疾病的包涵体中发现，包括肌萎缩性侧索硬化症、额颞叶痴呆、帕金森病和阿尔茨海默病。随后在散发性和家族性ALS患者中报告了TDP-43编码基因TARDBP的突变。为了研究这些突变体的致病性，在细胞系、原代培养的运动神经元和活的斑马鱼胚胎中测试了三种一致报道的TARDBP突变（A315 T、G348 C和A382 T）的影响。当通过瞬时转染在COS 1和Neuro 2A细胞中表达时，三种突变体和野生型（WT）人TDP-43中的每一种都定位于细胞核。然而，当表达在运动神经元从分离的脊髓文化，这些突变体的TARDBP等位基因，但不那么WT TARDBP，神经毒性，伴随着核周定位和聚集的TDP-43。最后，突变体的过度表达，但WT，人TARDBP引起的运动表型在斑马鱼（Danio rerio）胚胎组成的较短的运动神经元轴突，过早和过度的分支，以及游泳缺陷。有趣的是，zebrafisfh tardbp的敲低导致类似的表型，其通过共表达WT而不是突变的人TARDBP来挽救。总之，这些方法表明，TARDBP突变导致运动神经元缺陷和毒性，这表明毒性功能获得以及新的功能丧失可能涉及突变TDP-43导致疾病发病的分子机制。
TDP-43 has been found in inclusion bodies of multiple neurological disorders, including amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson's disease and Alzheimer's disease. Mutations in the TDP-43 encoding gene, TARDBP, have been subsequently reported in sporadic and familial ALS patients. In order to investigate the pathogenic nature of these mutants, the effects of three consistently reported TARDBP mutations (A315T, G348C and A382T) were tested in cell lines, primary cultured motor neurons and living zebrafish embryos. Each of the three mutants and wild-type (WT) human TDP-43 localized to nuclei when expressed in COS1 and Neuro2A cells by transient transfection. However, when expressed in motor neurons from dissociated spinal cord cultures these mutant TARDBP alleles, but less so for WT TARDBP, were neurotoxic, concomitant with perinuclear localization and aggregation of TDP-43. Finally, overexpression of mutant, but less so of WT, human TARDBP caused a motor phenotype in zebrafish (Danio rerio) embryos consisting of shorter motor neuronal axons, premature and excessive branching as well as swimming deficits. Interestingly, knock-down of zebrafisfh tardbp led to a similar phenotype, which was rescued by co-expressing WT but not mutant human TARDBP. Together these approaches showed that TARDBP mutations cause motor neuron defects and toxicity, suggesting that both a toxic gain of function as well as a novel loss of function may be involved in the molecular mechanism by which mutant TDP-43 contributes to disease pathogenesis.