Department of "General and Clinical Pathology, Forensic Medicine, Deontology and Dermatovenerology", Medical Faculty, Trakia University, 11 Armeiska Str., 6000 Stara Zagora, Bulgaria.
Department of "Medical Chemistry and Biochemistry", Medical Faculty, Trakia University, 11 Armeiska Str., 6000 Stara Zagora, Bulgaria.
Int J Mol Sci. 2023 Mar 18;24(6):5807. doi: 10.3390/ijms24065807.
Oxidative stress and the albumin oxidized form can lead to hypoalbuminemia, which is a predisposing factor for reduced treatment effectiveness and an increased mortality rate in severe COVID-19 patients. The aim of the study is to evaluate the application of free radical 3-Maleimido-PROXYL and SDSL-EPR spectroscopy in the in vitro determination of ox/red HSA in serum samples from patients with SARS-CoV-2 infection. Venous blood was collected from patients intubated (pO < 90%) with a positive PCR test for SARS-CoV-2 and controls. At the 120th minute after the incubation of the serum samples from both groups with the 3-Maleimido-PROXYL, the EPR measurement was started. The high levels of free radicals were determined through the nitroxide radical TEMPOL, which probably led to increased oxidation of HSA and hypoalbuminemia in severe COVID-19. The double-integrated spectra of 3-Maleimido-PROXYL radical showed a low degree of connectivity due to high levels of oxidized albumin in COVID-19 patients. The low concentrations of reduced albumin in serum samples partially inhibit spin-label rotation, with A values and ΔH spectral parameters comparable to those of 3-Maleimido-PROXYL/DMSO. Based on the obtained results, we suggest that the stable nitroxide radical 3-Maleimido-PROXYL can be successfully used as a marker to study oxidized albumin levels in COVID-19.
氧化应激和白蛋白氧化形式可导致低白蛋白血症，这是严重 COVID-19 患者降低治疗效果和增加死亡率的一个诱发因素。本研究的目的是评估自由基 3-马来酰亚胺-PROXYL 和 SDSL-EPR 光谱在体外测定 SARS-CoV-2 感染患者血清样本中 ox/red HSA 的应用。从接受插管治疗（pO < 90%）且 SARS-CoV-2 PCR 检测呈阳性的患者和对照组中采集静脉血。在两组血清样本与 3-马来酰亚胺-PROXYL 孵育 120 分钟后，开始进行 EPR 测量。通过氮氧自由基 TEMPOL 确定了自由基的高水平，这可能导致严重 COVID-19 中 HSA 的氧化增加和低白蛋白血症。3-马来酰亚胺-PROXYL 自由基的双积分光谱由于 COVID-19 患者中氧化白蛋白水平较高，显示出低连接度。血清样本中还原型白蛋白的低浓度部分抑制自旋标记的旋转，A 值和 ΔH 光谱参数与 3-马来酰亚胺-PROXYL/DMSO 相当。基于获得的结果，我们建议稳定的氮氧自由基 3-马来酰亚胺-PROXYL 可成功用作研究 COVID-19 中氧化白蛋白水平的标志物。
