Screening of differential proteins of placenta tissues in patients with pre-eclampsia by iTRAQ proteomics techniques

Isotopically labeled relative and absolute quantification (iTRAQ) were applied together with liquid chromatogram-tandem mass spectrometry (LC-MS/MS) technique to screen and differentiate normal tissues and differential proteins of placenta tissue in the pre-eclampsia group, and to seek for a pre-eclampsia biomarker.

Thirty patients with severe pre-eclampsia (pre-eclampsia group) and 30 patients with normal full-term pregnancy (control group), who were admitted by the Obstetrical Department of The Affiliated Hospital of Qingdao University from December 2014 to June 2015, were collected for this study. Part of the placenta tissue was sampled following cesarean section to extract the total protein that was degenerated, reduced and enzymatically hydrolyzed. Following iTRAQ, mass spectroscopy was used for differentiation to obtain differential proteins in the expression.

A total of 234 differential proteins were identified. The comparison between the severe pre-eclampsia group and the control group indicated over 1.5-folds of expression abundance difference (upregulation ratio >1.50, or downregulation ratio <0.67). The difference was statistically significant in 24 protein points in total, among which the expression of 14 protein points was upregulated compared with that of the control group, and the expression of 10 protein points was downregulated.

iTRAQ combined with the LC-MS/MS technique can effectively screen differential proteins in placenta tissues of patients with pre-eclampsia.