Objectives: To study the changes of protein levels in peripheral blood after it dried.
Methods: The proteins from whole blood and bloodstains were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and normalized by the label-free quantification (LFQ) method. The differential proteins were analyzed by using R 4.2.1 software, limma and edgeR package. The analysis of biological function, signaling pathway and subcellular localization for the differential proteins was then performed.
Results: A total of 623 and 596 proteins were detected in whole blood and bloodstains, respectively, of which 31 were statistically significant in the quantitative results, including 10 up-regulated and 21 down-regulated proteins in bloodstains.
Conclusions: The protein abundances in whole blood and bloodstains are highly correlated, and the variation of protein abundances may be related to the changes of endogenous and structural proteins in cells. The application of proteomics technology can assist the screening and identification of protein biomarkers, thereby introducing new biomarkers for forensic research.
目的: 研究外周血形成干燥血斑后蛋白质水平的变化。方法: 应用液相色谱-串联质谱法（LC-MS/MS）和非标记定量（label-free quantification，LFQ）策略进行全血和血斑的蛋白质检测，分别采用R 4.2.1软件limma包和edgeR包筛选差异蛋白质，再进行生物学功能、信号通路和亚细胞定位分析。结果: 全血和血斑中分别检测到623个和596个蛋白质，其中31个蛋白质的定量差异具有统计学意义，包括10个丰度在血斑中上调和21个丰度在血斑中下调的蛋白质。结论: 全血和血斑中的蛋白质丰度高度相关，两者间蛋白质丰度的改变可能与细胞内源性蛋白和结构蛋白的变化相关。应用蛋白质组学技术可以辅助蛋白质生物标志物的筛选和鉴定，为法医学研究引入新型生物标志物。.
Keywords: bloodstains; differential protein; forensic medicine; label-free quantification method; liquid chromatography-tandem mass spectrometry (LC-MS/MS); proteomics; whole blood.