title: Sildenafil stimulates human trophoblast invasion through nitric oxide and guanosine 3',5'-cyclic monophosphate signaling.
abstract: OBJECTIVE
  To determine the effect of sildenafil, a phosphodiesterase type 5 inhibitor, on trophoblast invasiveness.
  
  
  METHODS
  Laboratory investigation.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Placental tissues discarded after first-trimester terminations were obtained from patients with informed consent.
  
  
  METHODS
  A cell line, HTR-8/SVneo, established from first-trimester cytotrophoblast, and villous explants, was treated with or without sildenafil, guanosine 3',5'-cyclic monophosphate (cGMP) analog, cGMP inhibitor, or L-NAME (N(G)-nitro-L-arginine methyl ester hydrochloride) and cultured on fibronectin or Matrigel. Integrins α6β4 and α1β1 were detected by immunocytochemistry.
  
  
  METHODS
  Trophoblast outgrowth from villous tips, cytotrophoblast cell invasion, and integrin immunostaining were assessed in cytotrophoblast and explant cultures.
  
  
  RESULTS
  Integrin expression in trophoblast cells ex vivo switched from α6 to α1, and invasiveness increased, when exposed to sildenafil or cGMP agonist. Either cGMP antagonist or L-NAME blocked integrin switching and invasion induced by sildenafil. Elevation of nitric oxide pharmacologically induced invasion, but not when cGMP antagonist was present.
  
  
  CONCLUSIONS
  Sildenafil altered trophoblast phenotype through a process dependent on nitric oxide availability and cGMP accumulation. In addition to its vasoactivity, sildenafil directly stimulates trophoblast extravillous differentiation, which would be favorable for implantation and reduce risk for adverse pregnancy outcomes.
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Jay M
authors: JM
authors: Bolnick
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Brian A
authors: BA
authors: Kilburn
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Alan D
authors: AD
authors: Bolnick
authors: Department of Obstetrics and Gynecology, Georgia Regents University, Augusta, Georgia.
authors: Michael P
authors: MP
authors: Diamond
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Manvinder
authors: M
authors: Singh
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Michael
authors: M
authors: Hertz
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan.
authors: Jing
authors: J
authors: Dai
authors: Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan; Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan; Program in Reproductive and Adult Endocrinology, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland. Electronic address: D.Armant@Wayne.edu.
authors: D Randall
authors: DR
authors: Armant
mesh_terms: D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D010064:Embryo Implantation / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism*; D010879:Piperazines / Q000008:administration & dosage*; D011687:Purines / Q000008:administration & dosage; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000008:administration & dosage*; D014327:Trophoblasts / Q000166:cytology* / Q000187:drug effects
chemical_list: D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D009569:Nitric Oxide; D000068677:Sildenafil Citrate; D006152:Cyclic GMP
keywords: Trophoblast invasion; guanosine 3′,5′-cyclic monophosphate; integrins; nitric oxide; phosphodiesterase-5 inhibitor