title: [Mek1 and Mek2 functions in the formation of the blood placental barrier].
abstract: The ERK/MAPK signaling pathway is involved in several cellular functions. Inactivation in mice of genes encoding members of this pathway is often associated with embryonic death resulting from abnormal placental development. The placenta is essential for nutritional and gaseous exchanges between maternal and embryonic circulations, as well as for the removal of metabolic wastes. These exchanges take place without direct contact between the two circulations. In mice, the hematoplacental barrier consists in a triple layer of trophoblast cells and endothelial cells of the embryo. MEK1 and MEK2 are double specificity serine-threonine/tyrosine kinases responsible for the activation of ERK1 and ERK2. Mek1 inactivation results in placental anomalies due to trophoblast cell proliferation and differentiation defects leading to severe delays in the development of placenta and causing the death of the embryo. Although Mek2(-/-) mutant mice survived without any apparent phenotype, double heterozygous Mek1(+/-)Mek2(+/-) mutants die during gestation from placental malformations. Together, these data emphasize the crucial role of the ERK/MAPK cascade in the formation of extraembryonic structures.
authors.affiliation: Centre de recherche en cancérologie de l'université Laval, centre de recherche du centre hospitalier universitaire de Québec, Québec G1R 2J6, Canada. valerie.nadeau.3@ulaval.ca
authors.forename: Valérie
authors.initials: V
authors.lastname: Nadeau
authors.forename: Vickram
authors.initials: V
authors.lastname: Bissonauth
authors.forename: Jean
authors.initials: J
authors.lastname: Charron
mesh_terms: D000818:Animals; D018916:Blood-Aqueous Barrier / Q000378:metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000235:genetics / Q000502:physiology*; D048370:MAP Kinase Kinase 2 / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D010920:Placenta / Q000378:metabolism*; D021041:Placental Circulation / Q000235:genetics* / Q000502:physiology; D011247:Pregnancy
chemical_list: D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2