Evidence of nitrosative damage in the brain white matter of patients with multiple sclerosis
Evidence of nitrosative damage in the brain white matter of patients with multiple sclerosis
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DOI：
10.1007/s11064-004-9695-2
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发表时间：
2005-01-01
影响因子：
4.4
通讯作者：
Pastuszyn, A
中科院分区：
文献类型：
--
作者：
Bizzozero, O;DeJesus, G;Pastuszyn, A
一氧化氮 (NO) 与实验性自身免疫性脑脊髓炎和多发性硬化症 (MS) 的病理生理学有关。 MS 中 NO 介导的蛋白质损伤似乎仅限于检测到 3-硝基酪氨酸的大斑块。为了确定亚硝化损伤是否发生在可见的多发性硬化症斑块之外，我们评估了八个多发性硬化症大脑的正常白质（NAWM）中各种NO触发的蛋白质修饰的发生情况，并将其与四个对照大脑的白质（WM）进行了比较。通过氨基酸分析和蛋白质印迹测定，在所研究的 MS 样品中没有发现酪氨酸硝化的证据，这表明它们不含有大量的噬菌斑衍生物质。病变组织中总髓鞘蛋白和蛋白脂质蛋白 (PLP) 的氨基酸组成以及 PLP 的脂肪酸组成也没有改变。此外，我们检测到游离蛋白质硫醇的数量没有变化，这表明氧化没有发生任何明显的程度。然而，MS-NAWM 中的亚硝酸盐水平高于对照 WM 中的水平，而在 MS-灰质 (GM) 中，该离子的浓度没有改变。此外，分析的五个 MS 样品与具有高水平神经胶质原纤维酸性蛋白的样品相同，通过“生物素开关”方法测定，显示蛋白质亚硝基硫醇含量增加。 GM 蛋白的 S-亚硝化再次正常。在对照和 MS 组织中均没有色氨酸和 N 末端氨基的 N-亚硝化迹象。总体而言，数据表明，多发性硬化症大脑中的 WM（而不是 GM）受到相当大的亚硝化应激。这是第一份提供多发性硬化症患者脑实质中蛋白质 S-亚硝化和亚硝酸盐含量增加的直接证据的报告。
Nitric oxide (NO) has been implicated in the pathophysiology of both experimental autoimmune encephalomyelitis and multiple sclerosis (MS). NO-mediated protein damage in MS appears to be confined to large plaques where 3-nitrotyrosine has been detected. To determine whether nitrosative damage takes place beyond visible MS plaques, the occurrence of various NO-triggered protein modifications in normal-appearing white matter (NAWM) of eight MS brains was assessed and compared to that in white matter (WM) of four control brains. As determined by amino acid analysis and western blotting, no evidence of tyrosine nitration was found in the MS samples studied, suggesting that they did not contain appreciable amounts of plaque-derived material. The amino acid composition of total myelin proteins and proteolipid protein (PLP) was also unaltered in the diseased tissue, as was the fatty acid composition of PLP. In addition, we detected no changes in the number of protein free thiols suggesting that oxidation do not occur to any appreciable extent. However, the levels of nitrite in MS-NAWM were higher than those in control WM, while in the MS-gray matter (GM) the concentration of this ion was unaltered. Furthermore, five of the MS samples analyzed, and the same as those with high levels of glial fibrilary acidic protein, showed increased amounts of protein nitrosothiols as determined by the "biotin switch" method. S-nitrosation of GM proteins was again normal. There was no indication of N-nitrosation of tryptophan and N-terminal amino groups in both control and MS tissue. Overall, the data suggests that WM, but not GM, from MS brains is subjected to considerable nitrosative stress. This is the first report to present direct evidence of increased protein S-nitrosation and nitrite content in the brain parenchyma of MS patients.