Preeclampsia is Associated with Decreased Methylation of the GNA12 Promoter

Preeclampsia, characterized by high blood pressure, albuminuria and other systemic disorders, is a serious complication during pregnancy. It has been reported that GNA12 is overexpressed during preeclampsia. In this study, we investigated the potential association between the methylation of the GNA12 promoter and preeclampsia. The methylation level at eight CpG sites of the GNA12 promoter was analyzed by MassARRAY in placenta and peripheral blood DNA samples from 50 preeclampsia patients and 50 normal pregnant women. In the placenta DNA samples, the methylation level at three CpG sites of the GNA12 promoter was significantly lower in the preeclampsia patients than in the controls. The difference was also significant at two of the three CpG sites in the peripheral blood DNA samples. The mRNA expression level of GNA12 in placenta was analyzed by real-time quantitative PCR in 20 cases and 20 controls. Consistent with the decreased methylation level, the mRNA expression level of GNA12 was higher in preeclampsia patients than in controls. Our results showed that preeclampsia is associated with decreased methylation of the GNA12 promoter, which can be detected in both the placenta and the peripheral blood of the pregnant women.