title: Decreased annexin A5 mRNA placental expression in pregnancies complicated by fetal growth restriction.
abstract: BACKGROUND
  The placental anticoagulant protein Annexin A5 (ANXA5) is highly expressed on the apical surfaces of syncytiotrophoblasts and plays an important role in maintaining blood fluidity in the placental circulation. We investigated the mRNA and protein expression of ANXA5 in placentas from pregnancies complicated by fetal growth restriction (FGR) compared with uncomplicated pregnancies.
  
  
  METHODS
  Placental tissue was collected from 18 pregnancies complicated by FGR and 16 pregnancies with a normal outcome. ANXA5 mRNA expression was quantified by Real-Time PCR (RT-PCR), and protein concentrations were measured by an enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  A decreased ANXA5 mRNA expression was observed in placenta samples from FGR-affected pregnancies compared to those from uncomplicated pregnancies. However, similar ANXA5 protein levels were measured in both specimen groups. No correlation was observed between ANXA5 mRNA and protein levels.
  
  
  CONCLUSIONS
  Transcriptional ANXA5 down-regulation was demonstrated in FGR-affected pregnancies, although protein levels were similar in FGR-related placentas and controls. We can speculate that either recruitment of the protein from the bloodstream or increased apoptosis or post-transcriptional modifications occur, which affect ANXA5 protein levels in FGR-related placentas. Further studies are required to reveal the role of ANXA5 in FGR pathology.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital, Heraklion, Crete, Greece.
authors.forename: Stavros
authors.initials: S
authors.lastname: Sifakis
authors.forename: Giannoula
authors.initials: G
authors.lastname: Soufla
authors.forename: Ourania
authors.initials: O
authors.lastname: Koukoura
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Soulitzis
authors.forename: Demetrios
authors.initials: D
authors.lastname: Koutroulakis
authors.forename: Nerea
authors.initials: N
authors.lastname: Maiz
authors.forename: Anastasia
authors.initials: A
authors.lastname: Konstantinidou
authors.forename: Efthimia
authors.initials: E
authors.lastname: Melissari
authors.forename: Demetrios A
authors.initials: DA
authors.lastname: Spandidos
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000235:genetics; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005317:Fetal Growth Retardation / Q000235:genetics* / Q000378:metabolism*; D008322:Mammals / Q000235:genetics / Q000378:metabolism; D013513:Obstetric Surgical Procedures; D010920:Placenta / Q000378:metabolism*; D021041:Placental Circulation / Q000235:genetics; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D017304:Annexin A5; D012333:RNA, Messenger