对 ALS 中去污剂不溶性蛋白质的特性分析表明，硝化应激与发病机制中的聚集之间存在因果关系。

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor neuron disease, and protein aggregation has been proposed as a possible pathogenetic mechanism. However, the aggregate protein constituents are poorly characterized so knowledge on the role of aggregation in pathogenesis is limited.

METHODOLOGY/PRINCIPAL FINDINGS: We carried out a proteomic analysis of the protein composition of the insoluble fraction, as a model of protein aggregates, from familial ALS (fALS) mouse model at different disease stages. We identified several proteins enriched in the detergent-insoluble fraction already at a preclinical stage, including intermediate filaments, chaperones and mitochondrial proteins. Aconitase, HSC70 and cyclophilin A were also significantly enriched in the insoluble fraction of spinal cords of ALS patients. Moreover, we found that the majority of proteins in mice and HSP90 in patients were tyrosine-nitrated. We therefore investigated the role of nitrative stress in aggregate formation in fALS-like murine motor neuron-neuroblastoma (NSC-34) cell lines. By inhibiting nitric oxide synthesis the amount of insoluble proteins, particularly aconitase, HSC70, cyclophilin A and SOD1 can be substantially reduced.

CONCLUSION/SIGNIFICANCE: Analysis of the insoluble fractions from cellular/mouse models and human tissues revealed novel aggregation-prone proteins and suggests that nitrative stress contribute to protein aggregate formation in ALS.

背景

肌萎缩性侧索硬化症（ALS）是一种进行性和致命性的运动神经元疾病，蛋白质聚集被认为是一种可能的发病机制。然而，聚集蛋白的组成成分特征描述较差，因此对聚集在发病机制中的作用的了解有限。

方法/主要发现：我们对不同疾病阶段的家族性 ALS (fALS) 小鼠模型的不可溶性部分（作为蛋白质聚集模型）的蛋白质组成进行了蛋白质组学分析。我们在临床前阶段就发现了几种在去污剂不可溶性部分中富集的蛋白质，包括中间丝、伴侣蛋白和线粒体蛋白。此外，我们还发现，在 ALS 患者的脊髓中，顺乌头酸酶、HSC70 和亲环素 A 也明显富集在不可溶性部分中。而且，我们发现大多数蛋白质在小鼠和 HSP90 在患者中都被酪氨酸硝化。因此，我们研究了氧化性应激在 fALS 样鼠运动神经元-神经母细胞瘤 (NSC-34) 细胞系中聚集形成中的作用。通过抑制一氧化氮合成，不可溶性蛋白的量，特别是顺乌头酸酶、HSC70、亲环素 A 和 SOD1 的量可以大大减少。

结论/意义：对细胞/小鼠模型和人类组织的不可溶性部分的分析揭示了新的易聚集蛋白，并表明氧化性应激有助于 ALS 中的蛋白质聚集形成。