Li MengLin, Zhao MinDi, Gao YouHe
National Key Laboratory of Medical Molecular Biology, Department of Physiology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China.
Sci China Life Sci. 2014 Jul;57(7):649-56. doi: 10.1007/s11427-014-4661-y. Epub 2014 Jun 7.
The most fundamental property of biomarkers is change. But changes are hard to maintain in plasma since it is strictly controlled by homeostatic mechanisms of the body. There is no homeostatic mechanism for urine. Besides, urine is partly a filtration of blood, and systematic information can be reflected in urine. We hypothesize that change of blood can be reflected in urine more sensitively. Here we introduce the interference into the blood by two anticoagulants heparin or argatroban. Plasma and urine proteins were profiled by LC-MS/MS and then validated by Western blot in totally six SD female rats before and after the drug treatments. In argatroban treated group, with exactly the same experimental procedure and the same cutoff value for both plasma and urine proteins, 62 proteins changed in urine, only one of which changed in plasma. In heparin treated group, 27 proteins changed in urine but only three other proteins changed in plasma. Both LC-MS/MS and Western blot analyses demonstrated drug-induced increases in transferrin and hemopexin levels in urine but not in plasma. Our data indicates that urine may serve as a source for more sensitive detection of protein biomarkers than plasma.
生物标志物最基本的特性是变化。但由于血浆受到机体稳态机制的严格调控，其变化难以维持。而尿液不存在稳态机制。此外，尿液部分是血液的滤过液，系统信息可在尿液中得以体现。我们推测血液的变化能更灵敏地反映在尿液中。在此，我们通过两种抗凝剂肝素或阿加曲班对血液进行干预。在药物处理前后，对总共6只雌性SD大鼠的血浆和尿液蛋白质进行液相色谱-串联质谱分析（LC-MS/MS），然后通过蛋白质印迹法进行验证。在阿加曲班组，采用完全相同的实验步骤以及相同的血浆和尿液蛋白质截断值，尿液中有62种蛋白质发生变化，而血浆中只有1种蛋白质发生变化。在肝素处理组，尿液中有27种蛋白质发生变化，而血浆中只有另外3种蛋白质发生变化。LC-MS/MS和蛋白质印迹分析均表明，药物诱导尿液中转铁蛋白和血红素结合蛋白水平升高，而血浆中未升高。我们的数据表明，相较于血浆，尿液可能是更灵敏地检测蛋白质生物标志物的来源。
