Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Bruxelles, Belgium.
Talanta. 2012 Sep 15;99:603-9. doi: 10.1016/j.talanta.2012.06.044. Epub 2012 Jun 26.
A high degree of uremia is common in patients with end-stage renal disease and has been linked to the development of chronic inflammation and cardiovascular diseases. In conditions where transplantation is not possible, uremia can be reduced by hemodialysis although the repeated interventions have been implicated in loss of renal function, partially as a result of chronic inflammation and/or oxidative stress processes. In this context, it has been suggested that myeloperoxidase (MPO) can contribute to the oxidative stress during hemodialysis and to the cardiovascular risk. Protein damages due to MPO activity have never been assessed during hemodialysis although two of its reaction products, 3-chlorotyrosine and homocitrulline, are of interest. Indeed, the first one is a specific product of MPO activity and the formation of the second one could be catalyzed by MPO. In order to analyze these products in plasma proteins, a total hydrolysis method followed by liquid chromatography mass spectrometry analysis was developed. Different conditions of hydrolysis were tested and the optimized procedure was assessed for complete hydrolysis and artifactual chlorination. Finally, the method was used for analyzing 3-chlorotyrosine and homocitrulline in plasma proteins during a hemodialysis session in fifteen patients and data were related to measurements of MPO concentration and activity. Both increases in MPO activity and protein-bound 3-chlorotyrosine were observed, highlighting the involvement of MPO in oxidative stress during hemodialysis and further demonstrating the link between hemodialysis and cardiovascular diseases.
终末期肾病患者常伴有高尿毒症血症，而尿毒症与慢性炎症和心血管疾病的发生发展有关。在无法进行移植的情况下，通过血液透析可以降低尿毒症，尽管反复的干预措施已被认为与肾功能丧失有关，这部分是由于慢性炎症和/或氧化应激过程。在这种情况下，已经有人提出髓过氧化物酶（MPO）可能导致血液透析过程中的氧化应激，并增加心血管风险。尽管其两种反应产物 3-氯酪氨酸和同型瓜氨酸很有意义，但在血液透析期间，从未评估过 MPO 活性引起的蛋白质损伤。事实上，第一个产物是 MPO 活性的特异性产物，第二个产物的形成可能由 MPO 催化。为了在血浆蛋白中分析这些产物，开发了一种总水解方法，随后进行液相色谱-质谱分析。测试了不同的水解条件，并评估了优化程序的完全水解和人为氯化情况。最后，该方法用于分析 15 名患者血液透析过程中血浆蛋白中的 3-氯酪氨酸和同型瓜氨酸，并将数据与 MPO 浓度和活性的测量结果相关联。观察到 MPO 活性和蛋白结合的 3-氯酪氨酸均增加，这突出了 MPO 在血液透析过程中氧化应激中的作用，并进一步证明了血液透析与心血管疾病之间的联系。
