HSD11B2, RUNX3, and LINE-1 Methylation in Placental DNA of Hypertensive Disorders of Pregnancy Patients.

Hypertensive Disorders of Pregnancy (HDsP) remain leading causes of maternal and perinatal morbidity and mortality. Growing evidence suggests the involvement of epigenetic factors, such as gene-specific and global DNA methylation changes, both in the etiology and as an effect of HDsP. In this study, we investigated the potential association between placental DNA methylation status in selected CpGs of HSD11B2 cortisol level controlling gene, RUNX3 tumor suppressor gene, and long interspersed nucleotide element-1 (LINE-1) repetitive elements and HDsP-preeclampsia (PE), gestational hypertension (GH), and chronic hypertension (CH). Methylation-specific polymerase chain reaction (MSP) and pyrosequencing (PSQ) were used to analyze placental DNA methylation. Plasma and urine cortisol and cortisone levels were measured using high performance liquid chromatography with fluorescence detection (HPLC-FLD), whereas serum progesterone level was determined by electrochemiluminescence immunoassay. The mean percentage of HSD11B2, RUNX3, and LINE-1 methylation was not altered in the placentas of patients with HDsP, as compared to the controls. However, among patients from PE, GH, and CH groups, several significant correlations were observed between the methylation status of HSD11B2, RUNX3, or LINE-1 and children's birth weight, gestational age at delivery, mother's age, and body mass index as well as hormones levels. These results indicate lack of association between methylation status of HSD11B2, RUNX3, or LINE-1 repetitive elements and HDsP. However, association of these parameters with some clinical variables may suggest the role of placental DNA methylation in fetal development and should be further explored.