Hydrogen sulfide producing enzymes in pregnancy and preeclampsia

Abstract Preeclampsia, a human pregnancy specific disorder is characterized by an anti-angiogenic state. As hydrogen sulfide (H 2 S) has pro-angiogenic and anti-oxidative characteristics, we hypothesized that H 2 S levels could play a role in the pathogenesis of preeclampsia and studied the placental expression of the H 2 S-producing enzymes cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS). CBS and CSE protein are expressed in the fetal-placental endothelium and CBS only in Hofbauer cells. CBS mRNA expression is decreased ( p  = 0.002) in early-onset preeclampsia, while CSE mRNA is unchanged. Thus, down regulation of CBS during early-onset preeclampsia may result in less H 2 S-production and may aid in the anti-angiogenic state.