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.