Proteomic analysis of proteins differentially expressed in preeclamptic trophoblasts.

Aims: To identify differential trophoblastic proteins associated with preeclampsia (PE) by proteomic analysis.

Methods: We isolated and purified placental trophoblasts from normotensive pregnant women and patients with PE by a continuous Percoll gradient. The expression of proteins was determined by sliver staining after two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Proteins of interest were identified using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS).

Results: The overall trophoblastic protein expression patterns in preeclamptic and corresponding normotensive placentas were quite similar except for some areas. Of 34 differentially expressed protein spots (p < 0.05 by paired t-test), seven differential proteins from nine spots were identified by MALDI-TOF-MS. The expression of the following proteins was repressed (p < 0.01): disulfide isomerase ER-60, peroxiredoxin 2, and Delta3,5-Delta2,4-dienoyl-CoA isomerase. Four proteins (protein disulfide isomerase precursor, endoplasmic reticulum resident protein, dihydrolipoyl dehydrogenase and TIM21-like protein) were found to be significantly upregulated in PE (p < 0.01).

Conclusion: We identified several proteins with significant altered expression in PE using 2D-PAGE. This method is a powerful technique with which to search for not only quantitative but also qualitative changes in a biological process of interest.