Taurine transport in human placental trophoblast is important for regulation of cell differentiation and survival

Cell Death Dis. 2013 Mar 21;4(3):e559. doi: 10.1038/cddis.2013.81.

Abstract

The outer epithelial cell layer of human placenta, the syncytiotrophoblast, is a specialised terminally differentiated multinucleate tissue. It is generated and renewed from underlying cytotrophoblast cells that undergo proliferation, differentiation and fusion with syncytiotrophoblast. Acquisition of fresh cellular components is thought to be balanced by apoptosis and shedding of aged nuclei. This process of trophoblast cell turnover maintains a functional syncytiotrophoblast, capable of sufficient nutrient transfer from mother to foetus. Foetal growth restriction (FGR) is a pregnancy complication associated with aberrant trophoblast turnover and reduced activity of certain amino acid transporters, including the taurine transporter (TauT). Taurine is the most abundant amino acid in human placenta implying an important physiological role within this tissue. Unlike other amino acids, taurine is not incorporated into proteins and in non-placental cell types represents an important osmolyte involved in cell volume regulation, and is also cytoprotective. Here, we investigated the role of taurine in trophoblast turnover using RNA interference to deplete primary human trophoblast cells of TauT and reduce intracellular taurine content. Trophoblast differentiation was compromised in TauT-deficient cells, and susceptibility of these cells to an inflammatory cytokine that is elevated in FGR was increased, evidenced by elevated levels of apoptosis. These data suggest an important role for taurine in trophoblast turnover and cytoprotection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Biological Transport
  • Cell Differentiation
  • Cell Size
  • Cell Survival / genetics
  • Cytoprotection
  • Female
  • Fetal Growth Retardation / genetics*
  • Fetal Growth Retardation / metabolism
  • Fetal Growth Retardation / pathology
  • Gene Expression
  • Gene Knockdown Techniques
  • Half-Life
  • Humans
  • Membrane Glycoproteins / antagonists & inhibitors
  • Membrane Glycoproteins / deficiency
  • Membrane Glycoproteins / genetics*
  • Membrane Transport Proteins / deficiency
  • Membrane Transport Proteins / genetics*
  • Pregnancy
  • RNA, Small Interfering / genetics
  • Taurine / metabolism*
  • Taurine / pharmacology
  • Trophoblasts / metabolism*
  • Trophoblasts / pathology
  • Tumor Necrosis Factor-alpha / biosynthesis

Substances

  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • RNA, Small Interfering
  • Tumor Necrosis Factor-alpha
  • taurine transporter
  • Taurine