6533b825fe1ef96bd12825b9

RESEARCH PRODUCT

Etude de l'influence de la leptine sur les mécanismes cellulaires de la mise en route du travail dans un modèle d'accouchement prématuré : approches pharmacologiques

subject

description

Maternal obesity is associated with a wide spectrum of adverse pregnancy outcomes leading to higher rates of postdate pregnancies or preterm deliveries. Finding new strategies for the management of the Threat of Preterm Labor (TPL) is an important Public Health issue. Indeed, the only available strategy (tocolytic drugs) inhibiting uterine contractions, does not allow delaying parturition for more than 48 hours. The physio-pathological mechanisms leading to TPL remain poorly understood, but it has been shown that labor onset is associated with a phenotypic switch of myometrial smooth muscle cell from a proliferative to a contractile phenotype. In this work, we investigated the effect of leptin, an adipokine synthesized by the placenta during pregnancy and that has been proposed for the management of preterm labor, as it is able to prevent in vitro uterine contractility, on human myometrial cell proliferation and differentiation. In this work, we demonstrated that leptin induces myometrial proliferation, with or without the induction of pro-inflammatory signaling. Indeed, we highlight that leptin at 50ng/ml is able to activate IL-6R/NFkB pro-inflammatory pathway described to play a role in the onset of labor while leptin at 6.25 ng/ml stimulates OB-R/ERK1/2 signaling pathway, leading to proliferation. In addition, preliminary results on cell differentiation have suggested that leptin at 6.25ng/ml is able to oppose this transition, whereas leptin at 50ng/ml induces cytoskeletal reorganization, COX2 and Cx43 protein expression and increased calcium influx, leading to effective myometrial contractions. Finally, this work emphasizes the potential value of leptin in the pharmacological management of TPL and it also strengthens the hypothesis that leptin might be a contributory factor in the delivery disorders observed in obese women.