Figure 1.
Schematic of the experimental design based on iTRAQ labeling combined with 2-D LC-MS/MS analysis of SI, SP, and de.
SCX, strong cation exchange. SI: urine specimens from patients with SIRS. SP: urine specimens from sepsis patients, acquired within 24 h of admission to the ICU. de: urine specimens from sepsis patients, acquired within 48 h before death.
Table 1.
Demographics of subjects in the discovery and verification stages.
Figure 2.
Proteins identified in the three sets (technical replicates).
Table 2.
Summary of differentially expressed proteins identified in SP/SI, de/SI and de/SP among the three sets.
Figure 3.
The analytical process for candidate target protein identification.
SI: urine specimens from patients with SIRS. SP: urine specimens from sepsis patients, acquired within 24 h of admission to the ICU. de: urine specimens from sepsis patients, acquired within 48 h before death. de/SI: proteins differentially expressed in de relative to SI. de/SP: proteins differentially expressed in de relative to SP. SP/SI: proteins differentially expressed in SP relative to SI.
Figure 4.
GO annotation of the final selected differentially expressed proteins.
These differentially expressed proteins were classified among three categories: cellular component (CC), molecular function (MF) and biological process (BP). According to the GO database, the top 10 components for CC, MF, BP of the selected differentially expressed proteins are shown along with their enrichment score, represented as a p-value.
Figure 5.
Western blot validation of three candidate markers in individual sepsis patients with different prognoses.
(A) Relative protein expression of SBP-1. The survivor group and non-survivor groups were 0.938±0.347 and 0.945±0.602 (p>0.05), respectively. (B) Relative protein expression of LAMP-1. The survivor group and non-survivor groups were 0.752±0.246 and 0.617±0.166 (p<0.05), respectively. (C) Relative protein expression of HSPG-2. The survivor and non-survivor groups were 0.802±0.282 and 0.880±0.606 (p>0.05), respectively.