Wild-type superoxide dismutase acquires binding and toxic properties of ALS-linked mutant forms through oxidation
Wild-type superoxide dismutase acquires binding and toxic properties of ALS-linked mutant forms through oxidation
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DOI：
10.1111/j.1471-4159.2007.04531.x
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发表时间：
2007-07-01
影响因子：
4.7
通讯作者：
Julien, Jean-Pierre
中科院分区：
文献类型：
--
作者：
Abou Ezzi, Samer;Urushitani, Makoto;Julien, Jean-Pierre
最近的研究表明，超氧化物歧化酶（SOD1）可能是神经退行性疾病中氧化损伤的主要靶标。为了测试野生型（WT）SOD1的氧化物种可能参与致病过程的可能性，我们分析了WT人类SOD1蛋白在体内或体外经过氧化氢（H（2）O（2））处理氧化后的特性。使用表达WT或肌萎缩侧索硬化症相关SOD1物种的转染Neuro2a细胞，我们发现暴露于H(2)O(2)会改变WT SOD1的特性。对细胞裂解物免疫沉淀物的蛋白质印迹分析表明，与突变型 SOD1 一样，氧化型 WT SOD1 可以与多聚泛素缀合，并可以与 Hsp70 相互作用。嗜铬素 B 是一种神经分泌蛋白，与突变体 SOD1 相互作用，但与 WT SOD1 不相互作用，它与来自经 H(2)O(2) 处理的 Neuro2a 细胞裂解物的氧化 WT SOD1 进行共免疫沉淀。用氧化型 WT SOD1 或突变型 SOD1 重组蛋白处理小胶质细胞（BV2 系）可诱导肿瘤坏死因子-α 和诱导型一氧化氮合酶。此外，培养的运动神经元暴露于氧化的WT SOD1会导致剂量依赖性细胞死亡，就像突变的SOD1蛋白一样。这些结果表明，WT SOD1 可能通过氧化损伤获得突变型 SOD1 的结合和毒性特性。
Recent studies suggest that superoxide dismutase (SOD1) may represent a major target of oxidative damage in neurodegenerative diseases. To test the possibility that oxidized species of wild-type (WT) SOD1 might be involved in pathogenic processes, we analyzed the properties of the WT human SOD1 protein after its oxidation in vivo or in vitro by hydrogen peroxide (H(2)O(2)) treatment. Using transfected Neuro2a cells expressing WT or amyotrophic lateral sclerosis-linked SOD1 species, we show that exposure to H(2)O(2) modifies the properties of WT SOD1. Western blot analysis of immunoprecipitates from cell lysates revealed that, like mutant SOD1, oxidized WT SOD1 can be conjugated with poly-ubiquitin and can interact with Hsp70. Chromogranin B, a neurosecretory protein that interacts with mutant SOD1 but not with WT SOD1, was co-immunoprecipitated with oxidized WT SOD1 from lysates of Neuro2a cells treated with H(2)O(2). Treatment of microglial cells (line BV2) with either oxidized WT SOD1 or mutant SOD1 recombinant proteins induced tumor necrosis factor-alpha and inducible nitric oxide synthase. Furthermore, exposure of cultured motor neurons to oxidized WT SOD1 caused dose-dependent cell death like mutant SOD1 proteins. These results suggest that WT SOD1 may acquire binding and toxic properties of mutant forms of SOD1 through oxidative damage.