title: Annexin-A5 promotes membrane resealing in human trophoblasts.
abstract: Annexin-A5 (AnxA5) is the smallest member of the annexins, a group of soluble proteins that bind to membranes containing negatively-charged phospholipids, principally phosphatidylserine, in a Ca(2+)-dependent manner. AnxA5 presents unique properties of binding and self-assembling on membrane surfaces, forming highly ordered two-dimensional (2D) arrays. We showed previously that AnxA5 plays a central role in the machinery of cell membrane repair of murine perivascular cells, promoting the resealing of membrane damages via the formation of 2D protein arrays at membrane disrupted sites and preventing the extension of membrane ruptures. As the placenta is one of the richest source of AnxA5 in humans, we investigated whether AnxA5 was involved in membrane repair in this organ. We addressed this question at the level of human trophoblasts, either mononucleated cytotrophoblasts or multinucleated syncytiotrophoblasts, in choriocarcinoma cells and primary trophoblasts. Using established procedure of laser irradiation and fluorescence microscopy, we observed that both human cytotrophoblasts and syncytiotrophoblasts repair efficiently a μm²-size disruption. Compared to wild-type cells, AnxA5-deficient trophoblasts exhibit severe defect of membrane repair. Through specifically binding to the disrupted site as early as a few seconds after membrane wounding, AnxA5 promotes membrane resealing of injured human trophoblasts. In addition, we observed that a large membrane area containing the disrupted site was released in the extracellular milieu. We propose mechanisms ensuring membrane resealing and subsequent lesion removal in human trophoblasts. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Carmeille
authors.affiliation: Fondation PremUP, Paris, F-75006, France; INSERM, U1139, Paris, F-75006, France; Université Paris Descartes, UMR-S1139 Sorbonne Pris Cité, Paris, F-75006, France.
authors.forename: Séverine A
authors.initials: SA
authors.lastname: Degrelle
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Plawinski
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors.forename: Flora
authors.initials: F
authors.lastname: Bouvet
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Gounou
authors.affiliation: Fondation PremUP, Paris, F-75006, France; INSERM, U1139, Paris, F-75006, France; Université Paris Descartes, UMR-S1139 Sorbonne Pris Cité, Paris, F-75006, France.
authors.forename: Danièle
authors.initials: D
authors.lastname: Evain-Brion
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors.forename: Alain R
authors.initials: AR
authors.lastname: Brisson
authors.affiliation: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France. Electronic address: a.bouter@cbmn.u-bordeaux.fr.
authors.forename: Anthony
authors.initials: A
authors.lastname: Bouter
mesh_terms: D017304:Annexin A5 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D011247:Pregnancy; D014327:Trophoblasts / Q000378:metabolism* / Q000473:pathology
chemical_list: D017304:Annexin A5
keywords: Annexin-A5; Lesion removal; Membrane repair; Membrane resealing; Placenta; Trophoblast