The development and clinical application of a new oxidative stress marker using glutathionylated protein

氧化应激有助于动脉粥样硬化的发生和发展。氧化应激的主要来源活性氧修饰蛋白质半胱氨酸残基，在半胱氨酸残基和谷胱甘肽之间建立二硫键，导致蛋白质的S-谷胱甘肽化，并且这种修饰仍然是可逆的。因此，我们假设使用S-谷胱甘肽化蛋白的生物标志物是反映动脉粥样硬化早期阶段的良好生物标志物。我们组成的抗体对S-谷胱甘肽脱辅基蛋白B100，低密度脂蛋白（LDL）胆固醇的组成部分。在具有动脉粥样硬化风险（如高血压、糖尿病和/或血脂异常）的患者中，用该抗体进行免疫印迹分析的血清值与由氧化修饰诱导的带负电荷的LDL亚组分相关。用抗体对颈动脉内膜切除术切片的免疫组织学分析显示，S-谷氨酰化ApoB 100定位于靠近血管腔的部位，但不是泡沫细胞积聚的部位。提示血清S-谷胱甘肽化ApoB 100可能是反映动脉粥样硬化相对早期阶段的氧化应激标志物。

Oxidative stress contributes to the development and progression of atherosclerosis. Reactive oxygen species, major sources of oxidative stress, modifies protein cysteine residues, where a disulfide bond is established between a cysteinyl residue and glutathione, leading to the S-glutathionylation of protein, and this modification can be still reversible. Therefore, we hypothesized a biomarker using S-glutathionylated protein is a good one reflecting an early phase of atherosclerosis. We composed the antibody against S-glutathionylation of apoprotein B100, a component of low-density lipoprotein (LDL) cholesterol. The serum values by immunoblot analysis with this antibody were correlated with negatively charged LDL subfractions, which are induced by oxidative modification, in patients with atherogenetic risks, such as hypertension, diabetes mellitus, and/or dyslipidemia. Immunohistological analysis of carotid endarterectomy sections with the antibody showed S-glutationylated ApoB100 localized at the site close to the vascular lumen, but not the site of foamy cell accumulation. These suggested that serum S-glutationylated ApoB100 may be an oxidative stress marker reflecting the relatively early phase of atherosclerosis.