Witko-Sarsat V, Friedlander M, Capeillère-Blandin C, Nguyen-Khoa T, Nguyen A T, Zingraff J, Jungers P, Descamps-Latscha B
INSERM U25, Department of Biochemistry, Necker Hôpital, CNRS URA 400, Paris, France.
Kidney Int. 1996 May;49(5):1304-13. doi: 10.1038/ki.1996.186.
Evidence suggests an imbalance between antioxidant and oxidant-generating systems resulting in oxidative stress in uremic patients. As plasma proteins are critical targets for oxidants, we developed a novel spectrophotometric assay which allows to detect advanced oxidation protein products (AOPP) in uremic plasma. By size-exclusion chromatography AOPP are retrieved in two distinct peaks at 600 and below 80 kDa in uremic plasma, while no such peaks are found in control plasma. Further biochemical characterization revealed that AOPP are carried by oxidized plasma proteins, especially albumin and do not have oxidant properties. AOPP increased in a dose-dependent manner following in vitro exposure of plasma or purified human serum albumin (HSA) to hypochlorous acid. Advanced glycation end products of human serum albumin (AGE-HSA) also increased AOPP levels. In vivo, plasma level of AOPP was the highest in patients on hemodialysis, followed by those on peritoneal dialysis and by undialyzed patients with advanced chronic renal failure. AOPP levels correlated with plasma concentrations of dityrosine and AGE-pentosidine, as indices of oxidant-mediated protein damage, but not with thiobarbituric reactive substances as lipid peroxidation markers. A close correlation was also found between AOPP and neopterin levels, suggesting that AOPP could be part in the monocyte-mediated inflammatory disorders associated with uremia. In conclusion, we propose the measurement of AOPP as a reliable marker to estimate the degree of oxidant-mediated protein damage in uremic patients and to predict the potential efficacy of therapeutic strategies aimed at reducing such an oxidative stress.
有证据表明，抗氧化和产生活性氧系统之间的失衡会导致尿毒症患者出现氧化应激。由于血浆蛋白是活性氧的关键作用靶点，我们开发了一种新型分光光度法，可用于检测尿毒症血浆中的晚期氧化蛋白产物（AOPP）。通过尺寸排阻色谱法，在尿毒症血浆中，AOPP在600 kDa及低于80 kDa处有两个不同的峰，而在对照血浆中未发现此类峰。进一步的生化特性分析表明，AOPP由氧化的血浆蛋白携带，尤其是白蛋白，且不具有氧化活性。血浆或纯化的人血清白蛋白（HSA）在体外暴露于次氯酸后，AOPP呈剂量依赖性增加。人血清白蛋白的晚期糖基化终产物（AGE-HSA）也会增加AOPP水平。在体内，血液透析患者的血浆AOPP水平最高，其次是腹膜透析患者，然后是未透析的晚期慢性肾衰竭患者。AOPP水平与作为氧化应激介导的蛋白质损伤指标的二酪氨酸和AGE-戊糖苷的血浆浓度相关，但与作为脂质过氧化标志物的硫代巴比妥酸反应性物质无关。AOPP与新蝶呤水平之间也存在密切相关性，这表明AOPP可能参与了与尿毒症相关的单核细胞介导的炎症反应。总之，我们建议将AOPP的检测作为一种可靠的标志物，以评估尿毒症患者氧化应激介导的蛋白质损伤程度，并预测旨在减轻这种氧化应激的治疗策略的潜在疗效。
