Generation of novel animal models for amyofrophic lateral sclerosis and studies on the molecular mechanisms underlying motor dysfunction

ALS 2中的功能缺失突变导致了许多青少年/婴儿隐性运动神经元疾病，表明其基因产物ALS 2在神经元亚群的维持和存活中起着至关重要的作用。然而，ALS 2在体内的正常生理作用和运动功能障碍的分子机制仍然是未知的。为了解决这些问题，我们在本研究中产生了几个品系的ALS 2转基因小鼠和Als 2敲除（KO）小鼠的同源品系。在小鼠中，ALS 2的缺失或过表达都不会单独产生严重的疾病表型。然而，当Als 2-KO小鼠与表达家族性ALS连锁的SOD 1H 46 R的SOD 1 R46 R小鼠系杂交时，Als 2-KO ; SOD 1H 46 R<H46R>小鼠显示出比SOD 1H 46 R小鼠早得多的运动功能障碍以及更短的寿命，表明ALS 2在体内与突变型SOD 1相关的运动神经元疾病的发作和/或进展中起作用。接下来，为了阐明神经元ALS 2的功能，我们在 ...更多信息 研究了ALS 2缺陷的原代培养神经元的细胞表型。ALS 2缺陷不仅导致海马神经元轴突生长延迟，而且还导致皮质神经元巨胞饮细胞活性水平降低，表明ALS 2通过调节膜动力学在神经元分化和/或发育中起调节剂的作用。最后，我们研究了一个新的ALS 2同源物ALS 2CL的分子特征，以及它与ALS 2的功能关系。结果表明，ALS 2CL是一种新的ALS 2相互作用蛋白，并参与ALS 2介导的内体动力学。总的来说，我们新产生的动物过表达和/或删除ALS 2应该提供宝贵的研究工具，以了解ALS 2介导的内体动力学和运动神经元在体内的长期生存能力之间的相互作用。这些小鼠的进一步表征也将阐明突变型SOD 1-linkedALS的发病机制中ALS 2介导的神经元功能的含义。少

Loss of function mutations in ALS2 account for a number of juvenile/infantile recessive motor neuron diseases, indicating that its gene product, ALS2, plays a crucial role in maintenance and survival for a subset of neurons. However, the normal physiological role of ALS2 in vivo and the molecular mechanisms underlying motor dysfunction are still unknown. To address these issues, we generated several lines of ALS2 transgenic mice and congenic lines of the Als2 knock-out (KO) mice in this study. Neither loss nor overexpression of ALS2 solely produced a severe disease phenotype in mice. However, when the Als2-KO mice was crossed with the SOD1R46R mouse line expressing familial ALS-linked SOD1H46R Als2-KO ; SOD1^<H46R>mice showed a much earlier motor dysfunction as well as a shorter life span than SODIH46R mice, suggesting that ALS2 plays a role in the onset and/or progression of motor neuron disease associated with mutant SOD1 in vivo. Next, to elucidate the neuronal ALS2 functions, we in … More vestigated cellular phenotypes of ALS2-deficient primary cultured neurons. ALS2 deficiency resulted not only in the delay of axon outgrowth in hippocampal neurons, but also in a decreased level of the macropinocytic activity in cortical neurons, suggesting that ALS2 acts as a modulator in neuronal differentiation and/or development through regulation of membrane dynamics. Finally, we investigated the molecular features of ALS2CL, a novel ALS2 homolog, and its functional relationship with ALS2. It was revealed that ALS2CL was a novel ALS2-interacting protein and was implicated in ALS2-mediated endosome dynamics. Collectively, our newly generated animals overexpressing and/or deleting ALS2 should provide invaluable research tools with which to understand the interplay between ALS2-mediated endosomal dynamics and the long-term viability of motor neurons in vivo. Further characterization of these mice will also clarify the implication of the ALS2-mediated neuronal functions in the pathogenesis for mutant SOD1-linkedALS. Less