ABSTRACT
Objective To investigate the feasibility of differential expression proteins identification in peripheral blood mononuclear cells (PBMCs) of sepsis patients using Data Independent Acquisition liquid chromatography-mass spectrometry (DIA LC-MS). Methods Prospective studies were employed and targeted at 10 sepsis patients admitted to the Intensive Care Unit (ICU) of Shanghai Fifth People's Hospital Affiliated to Fudan University from April 2016 to July 2016. And 10 patients admitted to the ICU with similar age and sex that were not complicated with sepsis were served as the control group.The proteins from peripheral blood mononuclear cells in 10 sepsis patients and 10 control persons were analyzed using the latest DIA LC-MS technology and the skyline data extraction software; the model of data obtained from the above analysis was further discriminatorily analyzed with principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA); then the differential proteins of peripheral blood mononuclear cells were analyzed by Pathway analysis and GO analysis. The possible markers were identified by preliminary screening according to variable importance in the projection (VIP). The top 3 proteins (VIP > 1, P< 0.05) were verified by ELISA and their ROC curves were analyzed. Results Totally 1062 fragment ions were identified and 119 proteins were obtained. Among them, 31 proteins were up-regulated and 88 proteins down-regulated. Pathway analysis showed that carbon metabolism, platelet activation, bacterial invasion of epithelium, and complement coagulation cascade activation were participated in the development of sepsis. ELISA showed that significant difference of HMGB-1, MMP-8, and LCN2 in the expression of peripheral blood mononuclear cells in the sepsis and control people (P<0.01). The area under the ROC curve is greater than 0.85, which has good sensitivity and specificity. Conclusions DIA-MS is a compelling way for detecting differential expression proteins. PCA, PLSDA and OPLSDA are suitable for pattern recognition. The high expression of HMGB-1, NGAL and MMP-8 in immune cells may be the potential biomarker of the disease, which lays the foundation for research of early diagnosis and treatment of sepsis.