Expression and distribution of nucleoside transporter proteins in the human syncytiotrophoblast

Mol Pharmacol. 2011 Nov;80(5):809-17. doi: 10.1124/mol.111.071837. Epub 2011 Aug 8.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blotting, Western
  • DNA Primers
  • Humans
  • Immunohistochemistry
  • Nucleoside Transport Proteins / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Trophoblasts / metabolism*

Substances

  • DNA Primers
  • Nucleoside Transport Proteins