title: Smad3: an emerging target for vocal fold fibrosis.
abstract: OBJECTIVE
  To determine the efficacy of small interfering RNA (siRNA) targeting Smad3 to mediate fibroplasia in vitro, to investigate the temporal regulation of Smad3 following vocal fold (VF) injury, and to determine the local and distal effects of Smad3 siRNA VF injection.
  
  
  METHODS
  In vitro and in vivo.
  
  
  METHODS
  In vitro, Smad3 regulation was examined at both the level of transcription and translation in a human VF cell line in response to Smad3 siRNA ± transforming growth factor β (TGF-β). Collagen transcription was also examined. In vivo, Smad3 messenger RNA (mRNA) expression was quantified as a function of time following rabbit VF injury. Also, the effects of injected Smad3 siRNA were assessed at local and distal sites.
  
  
  RESULTS
  Smad3 siRNA knocked down Smad3 transcription and translation and limited TGF-β-mediated collagen mRNA expression with minimal cytotoxicity in vitro. In vivo, Smad3 mRNA increased 1 day following VF injury and remained elevated through day 7. Smad3 siRNA injection into the uninjured vocal fold had no local or distant effect on Smad3 mRNA at multiple organ sites.
  
  
  CONCLUSIONS
  These data provide a foundation for further investigation regarding the development of novel RNA-based therapeutics for the VF, specifically locally delivered siRNA for challenging fibrotic conditions of the VF.
authors.affiliation: Department of Otolaryngology, NYU Voice Center, New York University School of Medicine, New York, New York, U.S.A.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Paul
authors.forename: Benjamin Y
authors.initials: BY
authors.lastname: Rafii
authors.forename: Sonate
authors.initials: S
authors.lastname: Gandonu
authors.forename: Renjie
authors.initials: R
authors.lastname: Bing
authors.forename: Hayley
authors.initials: H
authors.lastname: Born
authors.forename: Milan R
authors.initials: MR
authors.lastname: Amin
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Branski
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D005355:Fibrosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry; D007818:Laryngeal Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D012333:RNA, Messenger / Q000235:genetics*; D034741:RNA, Small Interfering / Q000494:pharmacology; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051900:Smad3 Protein / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000235:genetics; D014827:Vocal Cords / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1
keywords: Smad3; Voice; dysphonia; fibrosis; inflammation; scarring; siRNA; vocal fold