Urinary proteomics analysis for sepsis biomarkers with iTRAQ labeling and two-dimensional liquid chromatography-tandem mass spectrometry

BACKGROUND: Proteomics has only recently been applied to the field of critical care research. Sepsis is a major factor contributing to intensive care unit admissions and deaths. The purpose of this study was to screen potential urinary biomarkers for sepsis using A proteomics approach. METHODS: Fifteen sepsis and 15 systemic inflammatory response syndrome patients were involved in this study. Urinary proteins were identified by isobaric tag for relative and absolute quantitation coupled with liquid chromatography-tandem mass spectrometry. Mass spectroscopy analysis was performed with the Mascot software and the International Protein Index. Bioinformatics analyses were performed using the hierarchy cluster analysis, the STRING software, the Gene Ontology, and the Kyoto Encyclopedia of Genes and Genome database. RESULTS: One hundred thirty proteins were identified, and 34 differentially expressed proteins were selected (fold change, >1.5). On the basis of the Gene Ontology and the Kyoto Encyclopedia of Genes and Genome database, these 34 proteins were identified to be involved in inflammation, immunity, and structural or cytoskeletal processes. Five proteins were selected by a protein-protein interaction network for sepsis differentiation: cadherin 1, haptoglobin, complement 3, alpha-1-antitrypsin, and ceruloplasmin. CONCLUSION: Urinary proteomics may represent a suitable approach for sepsis-related research. The detection of urinary biomarkers is expected to become a noninvasive and acceptable method, which facilitates the close surveillance of diseases and reduces medical costs. (J Trauma Acute Care Surg. 2013;74: 940-945. Copyright (c) 2013 by Lippincott Williams & Wilkins)