title: Placental alkaline phosphatase de-phosphorylates insulin-like growth factor (IGF)-binding protein-1.
abstract: BACKGROUND
  Insulin-like growth factors (IGF) regulate fetal growth through their effects on placenta. Their actions are influenced by IGF binding protein-1. Phosphorylated IGFBP-1 (pIGFBP-1) has high affinity for IGF-I and usually inhibits IGF-I activity but during pregnancy, it is de-phosphorylated to generate lower affinity isoforms and consequently, increased IGF bioavailability. Here we investigate the role of placenta in this process.
  
  
  RESULTS
  Our data show that term human placental explants, but not their conditioned medium, can de-phosphorylate IGFBP-1 through the action of placental alkaline phosphatase (PLAP).
  
  
  CONCLUSIONS
  PLAP-mediated de-phosphorylation of IGFBP-1 may provide a mechanism for controlling IGF-I bioavailability and action at the maternal/fetal interface.
authors.affiliation: Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK.
authors.forename: A L
authors.initials: AL
authors.lastname: Solomon
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK.
authors.forename: K W
authors.initials: KW
authors.lastname: Siddals
authors.affiliation: Gravida, University of Auckland, Auckland, New Zealand.
authors.forename: P N
authors.initials: PN
authors.lastname: Baker
authors.affiliation: Centre for Imaging Sciences, Institute of Population Health, University of Manchester, Manchester Academic Health Sciences Centre, Manchester, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Gibson
authors.affiliation: Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Aplin
authors.affiliation: Maternal and Fetal Health Research Centre, University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK; Maternal and Fetal Health Research Centre, St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, UK. Electronic address: melissa.westwood@manchester.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Westwood
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D005260:Female; D047109:Fetal Development; D058851:GPI-Linked Proteins / Q000378:metabolism; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000737:chemistry / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D008431:Maternal-Fetal Exchange; D010766:Phosphorylation; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism
chemical_list: D058851:GPI-Linked Proteins; C032231:IGFBP1 protein, human; D018970:Insulin-Like Growth Factor Binding Protein 1; D007527:Isoenzymes; D020033:Protein Isoforms; D007334:Insulin-Like Growth Factor I; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental
keywords: IGF; IGFBP-1; Maternal; PLAP; Trophoblast