title: Evidence for Differential Glycosylation of Trophoblast Cell Types.
abstract: Human placental villi are surfaced by the syncytiotrophoblast (STB), with a layer of cytotrophoblasts (CTB) positioned just beneath the STB. STB in normal term pregnancies is exposed to maternal immune cells in the placental intervillous space. Extravillous cytotrophoblasts (EVT) invade the decidua and spiral arteries, where they act in conjunction with natural killer (NK) cells to convert the spiral arteries into flaccid conduits for maternal blood that support a 3-4 fold increase in the rate of maternal blood flow into the placental intervillous space. The functional roles of these distinct trophoblast subtypes during pregnancy suggested that they could be differentially glycosylated. Glycomic analysis of these trophoblasts has revealed the expression of elevated levels of biantennary N-glycans in STB and CTB, with the majority of them bearing a bisecting GlcNAc. N-glycans terminated with polylactosamine extensions were also detected at low levels. A subset of the N-glycans linked to these trophoblasts were sialylated, primarily with terminal NeuAcα2-3Gal sequences. EVT were decorated with the same N-glycans as STB and CTB, except in different proportions. The level of bisecting type N-glycans was reduced, but the level of N-glycans decorated with polylactosamine sequences were substantially elevated compared with the other types of trophoblasts. The level of triantennary and tetraantennary N-glycans was also elevated in EVT. The sialylated N-glycans derived from EVT were completely susceptible to an α2-3 specific neuraminidase (sialidase S). The possibility exists that the N-glycans associated with these different trophoblast subpopulations could act as functional groups. These potential relationships will be considered.
authors.affiliation: From the ‡Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom;
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: From the ‡Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom;
authors.forename: Poh-Choo
authors.initials: PC
authors.lastname: Pang
authors.affiliation: §Department of Gynaecology and Obstetrics, Faculty of Medicine, Geneva, Switzerland;
authors.forename: Marie E
authors.initials: ME
authors.lastname: Cohen
authors.affiliation: ¶Department of Obstetrics and Gynecology, Washington University, School of Medicine, St. Louis, Missouri 63110;
authors.forename: Mark S
authors.initials: MS
authors.lastname: Longtine
authors.affiliation: ‖Division of Reproductive and Perinatal Research, Department of Obstetrics, Gynecology and Women's Health, School of Medicine, University of Missouri, Columbia, Missouri 65212;
authors.forename: Danny J
authors.initials: DJ
authors.lastname: Schust
authors.affiliation: From the ‡Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom;
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Haslam
authors.affiliation: **Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Reproductive Medicine Research Group, Charité-Universitätsmedizin Berlin, Berlin, Germany clarkgf@health.missouri.edu a.dell@imperial.ac.uk Sandra.Blois@charite.de.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Blois
authors.affiliation: From the ‡Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom; clarkgf@health.missouri.edu a.dell@imperial.ac.uk Sandra.Blois@charite.de.
authors.forename: Anne
authors.initials: A
authors.lastname: Dell
authors.affiliation: ‖Division of Reproductive and Perinatal Research, Department of Obstetrics, Gynecology and Women's Health, School of Medicine, University of Missouri, Columbia, Missouri 65212; clarkgf@health.missouri.edu a.dell@imperial.ac.uk Sandra.Blois@charite.de.
authors.forename: Gary F
authors.initials: GF
authors.lastname: Clark
mesh_terms: D000606:Amino Sugars / Q000378:metabolism; D005260:Female; D054794:Glycomics / Q000379:methods*; D006031:Glycosylation; D006801:Humans; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011247:Pregnancy; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D000606:Amino Sugars; D011134:Polysaccharides; C066929:polylactosamine