[Implications of retinoid pathway in human fetal membranes: study of target genes]

Retinoids (active derivatives of vitamin A) were already demonstrated to be important morphogenes and their implication at the placental and fetal level was already established. A new field of research is now developed in order to show their role on fetal membranes constituted by amnion and chorion. To describe the role of retinoids on these membranes, our studies were focused on target gene research. Firstly, all metabolism enzymes needed to vitamin A pathways were demonstrated to be present and active in signal transduction. Secondly, a bioinformatic analysis was performed to assess a list of potential target genes that could be classified in different biological pathways (inflammation, retinoids, hormones, vascularization, extracellular matrix and water homeostasis). Then, it was demonstrated that the gene coding for PLAT, implied in the degradation of extracellular matrix during programmed or premature rupture of membranes, is regulated by retinoids in a two steps mechanism. Finally, preliminary data showed that some aquaporins, which control water transport across membranes, are expressed and regulated by retinoids in the fetal membranes. A disregulation in pathologies like oligo or poly-hydramnios can be anticipated. Improvement of our knowledge about the retinoid implications is a key point in order to obtain a precise and complete documented cartography of the vitamin A (regulating) in amniotic membranes (regulated) that will permit the development of new diagnostic and therapeutic strategies.