Karlsson Páll, Droce Aida, Moser Jakob M, Cuhlmann Simon, Padilla Carolina Ortiz, Heimann Peter, Bartsch Jörg W, Füchtbauer Annette, Füchtbauer Ernst-Martin, Schmitt-John Thomas
Molecular Biology and Genetics Department, Aarhus University, Aarhus 8000, Denmark.
Int J Mol Sci. 2013 May 24;14(6):10908-25. doi: 10.3390/ijms140610908.
The identification of the mutation causing the phenotype of the amyotrophic lateral sclerosis (ALS) model mouse, wobbler, has linked motor neuron degeneration with retrograde vesicle traffic. The wobbler mutation affects protein stability of Vps54, a ubiquitously expressed vesicle-tethering factor and leads to partial loss of Vps54 function. Moreover, the Vps54 null mutation causes embryonic lethality, which is associated with extensive membrane blebbing in the neural tube and is most likely a consequence of impaired vesicle transport. Investigation of cells derived from wobbler and Vps54 null mutant embryos demonstrates impaired retrograde transport of the Cholera-toxin B subunit to the trans-Golgi network and mis-sorting of mannose-6-phosphate receptors and cargo proteins dependent on retrograde vesicle transport. Endocytosis assays demonstrate no difference between wobbler and wild type cells, indicating that the retrograde vesicle traffic to the trans-Golgi network, but not endocytosis, is affected in Vps54 mutant cells. The results obtained on wobbler cells were extended to test the use of cultured skin fibroblasts from human ALS patients to investigate the retrograde vesicle traffic. Analysis of skin fibroblasts of ALS patients will support the investigation of the critical role of the retrograde vesicle transport in ALS pathogenesis and might yield a diagnostic prospect.
对导致肌萎缩侧索硬化症（ALS）模型小鼠“摇摆鼠”表型的突变进行鉴定，已将运动神经元变性与逆行囊泡运输联系起来。“摇摆鼠”突变影响Vps54的蛋白质稳定性，Vps54是一种普遍表达的囊泡拴系因子，会导致Vps54功能部分丧失。此外，Vps54基因敲除突变会导致胚胎致死，这与神经管中广泛的膜泡形成有关，很可能是囊泡运输受损的结果。对来自“摇摆鼠”和Vps54基因敲除突变胚胎的细胞进行研究，结果表明霍乱毒素B亚基向反式高尔基体网络的逆行运输受损，且依赖逆行囊泡运输的甘露糖-6-磷酸受体和货物蛋白分选错误。内吞作用分析表明，“摇摆鼠”细胞与野生型细胞之间没有差异，这表明在Vps54突变细胞中，向反式高尔基体网络的逆行囊泡运输受到影响，而非内吞作用。在“摇摆鼠”细胞上获得的结果被扩展到对来自人类ALS患者的培养皮肤成纤维细胞的研究，以测试逆行囊泡运输情况。对ALS患者皮肤成纤维细胞的分析将支持对逆行囊泡运输在ALS发病机制中的关键作用的研究，并可能带来诊断前景。
