title: Ontogenetic localization and distribution of S-100beta protein in human placental tissues.
abstract: OBJECTIVE
  To investigate whether S-100beta, a brain-specific protein found in amniotic fluid and fetal circulation, is present in fetoplacental tissues throughout gestation.
  
  
  METHODS
  S-100beta protein localization and concentration were assessed in placentae, fetal membranes, and cord vessels. Tissues were obtained from 40 pregnant women at different gestational ages: first trimester (n = 10), second trimester (n = 10), early third trimester (n = 10), and late third trimester (n = 10).
  
  
  RESULTS
  In the placenta, S-100beta was localized in villous and intermediate trophoblast cells. The intensity of immunostaining and protein concentration increased with advancing gestation. S-100beta protein was also present in amnion, trophoblast, and decidual cells of fetal membranes, and in endothelial cells of umbilical vessels at all gestational ages.
  
  
  CONCLUSIONS
  This study demonstrated that fetoplacental tissues contain S-100beta protein, suggesting that these tissues may, at least in part, be responsible for the high level found in the fetal circulation. Although the significance of placental S-100beta is unknown, this origin should be taken into account when this protein is used as a marker of brain injury in the fetus or infant at birth.
authors.affiliation: Laboratory of Perinatal Medicine and Molecular Biology, Second Institute of Obstetrics and Gynecology, University of Rome La Sapienza, Rome, Italy. emanuelamarinoni@hotmail.com
authors.forename: Emanuela
authors.initials: E
authors.lastname: Marinoni
authors.forename: Romolo
authors.initials: R
authors.lastname: Di Iorio
authors.forename: Diego
authors.initials: D
authors.lastname: Gazzolo
authors.forename: Claudia
authors.initials: C
authors.lastname: Lucchini
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Michetti
authors.forename: Valentina
authors.initials: V
authors.lastname: Corvino
authors.forename: Ermelando V
authors.initials: EV
authors.lastname: Cosmi
mesh_terms: D015153:Blotting, Western; D005321:Extraembryonic Membranes / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D009414:Nerve Growth Factors; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy / Q000378:metabolism*; D011264:Pregnancy Trimesters; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism*; D014018:Tissue Distribution; D014471:Umbilical Veins / Q000378:metabolism*
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins