Elevated placental expression at the maternal-fetal interface but diminished maternal circulatory kisspeptin in preeclamptic pregnancies

Objective: To investigate the placental mRNA and protein expression of metastasis suppressor gene Kiss-1 and the transcript expression of its receptor GPR-54 across the maternal-fetal interface of healthy and preeclamptic pregnancies. To furthermore compare placental tissue kisspeptin expression to circulatory kisspeptin levels in these pregnancies. Setting: Secondary and Tertiary Hospital Setting in Cape Town, South Africa. Population: Patients with and without preeclampsia undergoing elective caesarean delivery. Methods: The placenta, placental bed and decidua parietalis as well as maternal and cord blood in both healthy and preeclamptic pregnancies were simultaneously sampled at elective caesarean delivery. RT-PCR was utilised to determine mRNA expression while immunohistochemistry was employed to investigate protein expression in maternal-fetal tissues. Circulating maternal and cord serum kisspeptin concentrations were determined using ELISA. Main outcome measures: Maternal-fetal tissue mRNA expression of Kiss-1 and GPR-54 as well as maternal/cord serum kisspeptin concentrations in healthy and preeclamptic pregnancies. Results: There was high placental kisspeptin expression but low circulating serum kisspeptin levels in pregnancies complicated by preeclampsia. Kiss-1 mRNA and protein expression was minimal in the maternal tissues (placental bed and decidua parietalis) of both healthy and preeclamptic pregnancies. No difference was found in Kiss-1 receptor (GPR-54) mRNA expression across maternal-fetal tissues of healthy and preeclamptic pregnancies. Conclusions: Increased placental kisspeptin expression is consistent with reduced trophoblast invasiveness and may represent a molecular mechanism that explains the development of preeclampsia. Decreased circulating kisspeptin concentration has the potential to be utilised as a marker for placental dysfunction. (C) 2015 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.