Amyotrophic lateral sclerosis (ALS) is a multifactorial fatal motoneuron disease without a cure. Ten percent of ALS cases can be pointed to a clear genetic cause, while the remaining 90% is classified as sporadic. Our study was aimed to uncover new connections within the ALS network through a bioinformatic approach, by which we identified C13orf18, recently named Pacer, as a new component of the autophagic machinery and potentially involved in ALS pathogenesis. Initially, we identified Pacer using a network-based bioinformatic analysis. Expression of Pacer was then investigated in vivo using spinal cord tissue from two ALS mouse models (SOD1G93A and TDP43A315T) and sporadic ALS patients. Mechanistic studies were performed in cell culture using the mouse motoneuron cell line NSC34. Loss of function of Pacer was achieved by knockdown using short-hairpin constructs. The effect of Pacer repression was investigated in the context of autophagy, SOD1 aggregation, and neuronal death. Using an unbiased network-based approach, we integrated all available ALS data to identify new functional interactions involved in ALS pathogenesis. We found that Pacer associates to an ALS-specific subnetwork composed of components of the autophagy pathway, one of the main cellular processes affected in the disease. Interestingly, we found that Pacer levels are significantly reduced in spinal cord tissue from sporadic ALS patients and in tissues from two ALS mouse models. In vitro, Pacer deficiency lead to impaired autophagy and accumulation of ALS-associated protein aggregates, which correlated with the induction of cell death. This study, therefore, identifies Pacer as a new regulator of proteostasis associated with ALS pathology.

中文翻译：

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网络方法将Pacer鉴定为参与ALS发病机制的自噬蛋白

肌萎缩性侧索硬化症（ALS）是一种无法治愈的多因素致命运动神经元疾病。可以将10％的ALS病例归因于明确的遗传原因，而其余90％被归类为零星的。我们的研究旨在通过生物信息学方法发现ALS网络中的新连接，通过该方法，我们将C13orf18（最近命名为Pacer）确定为自噬机制的新组成部分，并可能参与ALS发病机理。最初，我们使用基于网络的生物信息学分析确定了Pacer。然后使用两种ALS小鼠模型（SOD1G93A和TDP43A315T）和散发性ALS患者的脊髓组织在体内研究Pacer的表达。使用小鼠运动神经元细胞系NSC34在细胞培养中进行了机理研究。通过使用短发夹结构的敲低可以实现Pacer功能的丧失。在自噬，SOD1聚集和神经元死亡的背景下研究了Pacer抑制的作用。使用无偏倚的基于网络的方法，我们集成了所有可用的ALS数据，以识别ALS发病机理中涉及的新功能相互作用。我们发现，Pacer与一个由自噬途径（该疾病所影响的主要细胞过程之一）的成分组成的ALS特定子网络相关。有趣的是，我们发现散发性ALS患者的脊髓组织和两个ALS小鼠模型的组织中Pacer的水平均显着降低。在体外，起搏器缺乏导致受损的自噬和与ALS相关的蛋白质聚集的积累，这与诱导细胞死亡有关。因此，这项研究