title: Vascular endothelial growth factor but not placental growth factor promotes trophoblast syncytialization in vitro.
abstract: OBJECTIVE
  The object of this study was to determine the effect of epithelial growth factor (EGF), vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) on the differentiation of first-trimester and term cytotrophoblasts.
  
  
  METHODS
  The first-trimester trophoblasts were isolated from villous tissue obtained at suction termination (n = 5), and the term trophoblasts were isolated from placentas (n = 6) at elective cesarean. Cultured cells were stimulated with EGF, VEGF, or PlGF at 0.5, 5, and 50 ng/mL, in the presence or absence of N(G)-nitro-L-arginine methyl ester hydrochloride (10(-4) M). Syncytialized trophoblasts were identified by immunostaining with antidesmosomal protein and anti-cytokeratin-7, whereas nuclei were counted in each syncytia using hematoxylin.
  
  
  RESULTS
  Without treatment, background levels of syncytialization were significantly higher in term preparations than first-trimester cells. With VEGF and EGF, the number and size of syncytia increased significantly for the first-trimester cytotrophoblasts (P <.05). Neither VEGF nor EGF had any effect on the syncytialization of cultured cells at term. Nitric oxide showed no involvement in syncytial induction, and PlGF had no effect on syncytialization of cytotrophoblasts, from either the first or third trimester.
  
  
  CONCLUSIONS
  Both EGF and VEGF appeared to enhance the in vitro syncytialization of first trimester cytotrophoblasts.
authors.affiliation: MRC Development Group, School of Human Development, Department of Obstetrics and Gynaecology, University of Nottingham, City Hospital, Nottingham, United Kingdom. ian.crocker@nottingham.ac.uk
authors.forename: I P
authors.initials: IP
authors.lastname: Crocker
authors.forename: B K
authors.initials: BK
authors.lastname: Strachan
authors.forename: G E
authors.initials: GE
authors.lastname: Lash
authors.forename: S
authors.initials: S
authors.lastname: Cooper
authors.forename: A Y
authors.initials: AY
authors.lastname: Warren
authors.forename: P N
authors.initials: PN
authors.lastname: Baker
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D016228:Endothelial Growth Factors / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008222:Lymphokines / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D000072483:Placenta Growth Factor; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000494:pharmacology*; D018709:Statistics, Nonparametric; D014327:Trophoblasts / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D008222:Lymphokines; C000608036:PGF protein, human; D011257:Pregnancy Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D000072483:Placenta Growth Factor; D004815:Epidermal Growth Factor; D019331:NG-Nitroarginine Methyl Ester