title: Estrogen attenuates TGF-β1 induced elastogenesis in rat urethral smooth muscle cells by inhibiting Smad response elements.
abstract: OBJECTIVE
  We investigated the effect and mechanism of estrogen on elastogenesis in urethral smooth muscle cells in vitro.
  
  
  METHODS
  Urethral smooth muscle cells were isolated from normal adult female rats. For elastogenesis assay cells were treated with TGF-β1, the potent TGF-β1 receptor inhibitor SB431542 and estrogen for 2 weeks. Real-time polymerase chain reaction was performed to assay gene expression during this process. Activity of the TGF-β1 responsive elements CAGA(12)-Luc and GCCG(12)-Luc were also assayed. Estrogen receptor and Smad2/3 interaction was evaluated by immunoprecipitation and Western blot.
  
  
  RESULTS
  TGF-β1 induced elastogenesis in rat urethral smooth muscle cells. This effect was partially blocked by estrogen and completely abrogated by SB431542. SB431542 completely inhibited activation of the Smad2/3 response element CAGA(12)-Luc and estrogen significantly inhibited activation. The Smad1/4 response element GCCG(12)-Luc was not affected by SB431542 treatment but estrogen partially inhibited the activation of GCCG(12)-Luc induced by TGF-β1. Estrogen receptor bound to Smad 2 and 3 in vitro.
  
  
  CONCLUSIONS
  Estrogen attenuated TGF-β1 induced elastogenesis via binding of its activated receptor to Smad2/3 to inhibit the TGF-β1 response element in rat urethral smooth muscle cells.
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Guiting
authors.initials: G
authors.lastname: Lin
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Amjad
authors.initials: A
authors.lastname: Alwaal
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Fionna
authors.initials: F
authors.lastname: Sun
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California; Department of Urology, Peking University First Hospital and Institute of Urology, Peking University, Beijing, People's Republic of China.
authors.forename: Huixi
authors.initials: H
authors.lastname: Li
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California; Department of Urology, Peking University First Hospital and Institute of Urology, Peking University, Beijing, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Guifang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Hongxiu
authors.initials: H
authors.lastname: Ning
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Lia
authors.initials: L
authors.lastname: Banie
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California.
authors.forename: Ching-Shwun
authors.initials: CS
authors.lastname: Lin
authors.affiliation: Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California-San Francisco, San Francisco, California. Electronic address: tlue@urol.ucsf.edu.
authors.forename: Tom F
authors.initials: TF
authors.lastname: Lue
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004547:Elastic Tissue / Q000502:physiology*; D004967:Estrogens / Q000494:pharmacology / Q000502:physiology*; D005260:Female; D032389:Myocytes, Smooth Muscle / Q000502:physiology*; D051381:Rats; D051899:Smad2 Protein / Q000037:antagonists & inhibitors / Q000502:physiology*; D051900:Smad3 Protein / Q000037:antagonists & inhibitors / Q000502:physiology*; D053773:Transforming Growth Factor beta1 / Q000502:physiology*; D014521:Urethra / Q000166:cytology*
chemical_list: D004967:Estrogens; D051899:Smad2 Protein; C497784:Smad2 protein, rat; D051900:Smad3 Protein; C497787:Smad3 protein, rat; D053773:Transforming Growth Factor beta1
keywords: elastic tissue; estrogens; muscle; smooth; transforming growth factor beta; urethra