Quantitative analysis of oxidized vitamin B1 metabolites generated by hypochlorous acid
Quantitative analysis of oxidized vitamin B1 metabolites generated by hypochlorous acid
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DOI：
10.1016/j.freeradbiomed.2020.03.010
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发表时间：
2020-05-20
影响因子：
7.4
通讯作者：
Shibata, Takahiro
中科院分区：
文献类型：
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作者：
Sasatsuki, Hitoshi;Nakazaki, Atsuo;Shibata, Takahiro
硫胺素是一种被称为维生素B1的水溶性基本维生素，在新陈代谢和能量产生等各种细胞过程中扮演着重要的辅助因子的角色。硫胺素还被认为是一种单线态氧清除剂和脂质过氧化抑制剂，具有抗氧化作用。然而，硫胺素的氧化机制和氧化代谢产物还没有完全确定。在本研究中，我们研究了硫胺素的氧化反应活性，发现硫胺素与次氯酸(HOCl)反应生成了三种产物。根据核磁共振和高分辨质谱学分析，确定了硫胺素的HOCl氧化代谢产物为甲氨基嘧啶(FAP)、硫胺素磺酸(TSA)和硫胺素亚磺酸酯(TSE)。为了评估这些氧化代谢物在体内的形成，我们建立了一种用液相色谱-串联质谱仪结合稳定同位素稀释法对氧化硫胺素代谢物进行定量的特异方法。结果表明，在佛波醇-12-肉豆蔻酸酯-醋酸酯处理的中性粒细胞培养上清液中，氧化硫胺素代谢产物以髓过氧化物酶依赖的方式产生。此外，与对照组相比，内毒素处理组小鼠肺组织中FAP和TSE的含量显著增加。这些发现不仅提供了对硫胺素氧化代谢的深入了解，而且提供了氧化硫胺素代谢物可能是与HOCl2相关的氧化应激的潜在生物标志物的可能性。
Thiamine, a water-soluble essential vitamin known as vitamin B1, acts as an important cofactor in various cellular processes, such as metabolism and energy production. Thiamine is also thought to have antioxidant effects as a singlet oxygen scavenger and a lipid peroxidation inhibitor. However, the oxidation mechanism and oxidized metabolites of thiamine are not completely established. In the present study, we investigated the oxidative reactivity of thiamine and found that three products were formed upon the reaction of thiamine with hypochlorous acid (HOCl). Based on the NMR and high resolution mass spectrometric analysis, the HOCl-oxi- dized metabolites of thiamine were identified as formylaminopyrimidine (FAP), thiamine sulfonic acid (TSA), and thiamine sulfinic ester (TSE). To evaluate the formation of these oxidized metabolites in vivo , we established a specific method for quantification of the oxidized thiamine metabolites using liquid chromatography -tandem mass spectrometry coupled with a stable isotope dilution method. Using this method, it was shown that the oxidized thiamine metabolites were generated in the culture media of phorbol-12-myristate-acetate-treated neutrophil-like cells in a myeloperoxidase-dependent manner. Moreover, significantly higher amounts of FAP and TSE were detected in the lung tissues of the lipopolysaccharide-treated mice compared to the controls. These findings provide not only insights into the oxidative metabolism of thiamine, but also the possibility that the oxidized thiamine metabolites may be potential biomarkers for HOCl-related oxidative stress.