Genomic and proteomic investigation of preeclampsia

Abstract

The aim of this study was to use proteomic and transcriptomic approaches to examine differences in protein and gene expression in maternal plasma between normal and preeclamptic pregnancies. Preeclampsia and control groups were compared with respect to the expression of CD34 and CD133 genes by quantitative polymerase chain reaction (qPCR) and heat shock protein (Hsp)27 and 70 by western blotting in blood samples from the pregnant women. Blood samples were obtained at gestational week 12-14 from 65 healthy pregnant women. Fetal DNA was isolated from the maternal blood and CD34 and CD133 were amplified by qPCR. Western blot analysis was used to examine the expression levels of Hsp27 and Hsp70 proteins. The analysis of CD133 by qPCR was unsuccessful in 7 women as the levels of fetal DNA were in the collected maternal blood samples were insufficient. Measurements of CD34 and CD133 were performed in 57 and 50 women, respectively. Preeclampsia developed in 6 (10.5%) of 57 women. qPCR results of 8 healthy pregnant women were used for the calibration of CD34 and CD133 levels, and the results for the remaining women were compared with the calibration values. CD34 expression was decreased in 30 (52.6%) and increased in 27 (47.4%) of 57 women. CD133 expression was decreased in 14 (28%) and increased in 36 (72%) of 50 women. CD34 expression was increased in 2 (33%) and 25 (49%) and decreased in 4 (66%) and 25 (51%) women with and without preeclampsia, respectively (P=0.467). CD133 expression was increased in 4 (66%) and 32 (72%); and decreased in 2 (33%) and 12 (28%) women with and without preeclampsia, respectively (P=0.756). Western blotting showed that the expression of Hsp27 and Hsp70 in the maternal serum of the preeclampsia group was significantly higher than that in the normal pregnancy group. CD34 and CD133 were found to be inadequate for use in the prediction of preeclampsia. However, it is noteworthy that CD133 levels were increased in 66 and 72% of women with and without preeclampsia, respectively. Hsps are expressed under various pathological conditions. These results suggest that conditions of oxidative stress increased the Hsp27 and Hsp70 protein levels.

Keywords: cell-free fetal DNA; non-invasive prenatal diagnosis; preeclampsia.

Figure 1.

Western blot analysis of Hsp70 and Hsp27 in normal and preeclamptic (PE) women. For each lane, 100 µg serum protein was loaded and subjected to SDS-PAGE followed by western blot analysis as described in Materials and methods. Hsp, heat shock protein; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Figure 2.

Quantitative results of western blot analysis of Hsp70 in normal and preeclamptic (PE) women. The y-axis indicates the band intensities defined by the number of pixels under each peak (n=6; *P<0.05 compared with the control group). Hsp, heat shock protein.

Figure 3.

Quantitative results of western blot analysis of Hsp27 in normal and preeclamptic women. The y-axis indicates the band intensities defined by the number of pixels under each peak. (n=6, *P<0.05 compared with the control group). Hsp, heat shock protein.