Steroid hormone imbalance is associated with the pathogenesis of preeclampsia. However, affected enzymes of steroid metabolism and gene and protein expression in serum and placenta have not been elucidated yet. We aimed to investigate steroid hormone profiles and precursor-to-product ratios in preeclamptic women compared to women with healthy pregnancy (controls) to identify potentially affected steroid hormones and their metabolizing enzymes. Also, we aimed to investigate whether the mRNA expression of these enzymes is different between the study groups and whether levels of serum mRNA expression reflect postnatal placental protein expression. Serum levels of 14 steroid hormones were measured at eight time points throughout pregnancy in nine preeclamptic women and 36 controls. Serum mRNA expression of selected steroid-metabolizing enzymes was assessed, and their protein expression was analyzed in additional nine preeclamptic women. Mean levels of sex steroid and corticosteroid hormones were significantly altered in preeclamptic women. Precursor-to-product ratios of 5α-reductase, aromatase and 11β-hydroxysteroid dehydrogenase 1 were significantly increased, those of steroid 17α-hydroxylase, 17β-hydroxysteroid-dehydrogenase, steroid 11β-hydroxylase and 11β-hydroxysteroid dehydrogenase 2 were significantly decreased. Serum mRNA expression and placenta protein expression were comparable between the groups. Results contribute to understanding the heterogeneity of preeclampsia and can thus promote future research in personalized medicine.
Keywords: precursor-to-product ratios; preeclampsia; steroid metabolism; steroid-metabolizing enzymes; steroids.