title: Expression and distribution of nucleoside transporter proteins in the human syncytiotrophoblast.
abstract: The plasma membrane distribution and related biological activity of nucleoside transporter proteins (NTs) were investigated in human syncytiotrophoblast from term placenta using a variety of approaches, including nucleoside uptake measurements into vesicles from selected plasma membrane domains, NT immunohistochemistry, and subcellular localization (basal, heavy, and light apical membranes as well as raft-enriched membranes from the apical domain). In contrast with other epithelia, in this epithelium, we have identified the high-affinity pyrimidine-preferring human concentrative nucleoside transporter (hCNT) 1 as the only hCNT-type protein expressed at both the basal and apical membranes. hCNT1 localization in lipid rafts is also dependent on its subcellular localization in the apical plasma membrane, suggesting a complex cellular and regional expression. Overall, this result favors the view that the placenta is a pyrimidine-preferring nucleoside sink from both maternal and fetal sides, and hCNT1 plays a major role in promoting pyrimidine salvage and placental growth. This finding may be of pharmacological relevance, because hCNT1 is known to interact with anticancer nucleoside-derived drugs and other molecules, such as nicotine and caffeine, for which a great variety of harmful effects on placental and fetal development, including intrauterine growth retardation, have been reported.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Ekaitz
authors.initials: E
authors.lastname: Errasti-Murugarren
authors.forename: Paula
authors.initials: P
authors.lastname: Díaz
authors.forename: Valeria
authors.initials: V
authors.lastname: Godoy
authors.forename: Gloria
authors.initials: G
authors.lastname: Riquelme
authors.forename: Marçal
authors.initials: M
authors.lastname: Pastor-Anglada
mesh_terms: D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D006801:Humans; D007150:Immunohistochemistry; D033703:Nucleoside Transport Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D033703:Nucleoside Transport Proteins