title: Role of caffeic Acid on collagen production in nasal polyp-derived fibroblasts.
abstract: OBJECTIVE
  Caffeic acids are known to have anti-oxidant, anti-inflammatory, immunomodulatory, and tissue reparative effects. The purposes of this study were to determine the effect of caffeic acid on transforming growth factor (TGF) β1-induced myofibroblast differentiation and collagen production, and to determine whether caffeic acid is involved in the antioxidant effect in nasal polyp-derived fibroblasts (NPDFs).
  
  
  METHODS
  NPDFs were pretreated with caffeic acid (1-10 µM) for 2 hours and stimulated with TGF-β1 (5 ng/mL) for 24 hours. The expression of α-smooth muscle actin (SMA), collagen types I and III, and Nox4 mRNA was determined by a reverse transcription-polymerase chain reaction, and the expression of α-SMA protein was determined by actin ned by immunofluorescence microscopy. The amount of total soluble collagen production was analyzed by the Sircol collagen dye-binding assay. The reactive oxygen species (ROS) generated by NPDFs were determined using 2',7'-dichlorfluorescein-diacetate. siNox4 was used to determine the effect of Nox4.
  
  
  RESULTS
  The expression of α-SMA and production of collagen were significantly increased following TGF-β1 treatment. In contrast, the level of expression of α-SMA and the level of production of collagen were decreased by pretreatment with caffeic acid. The activation of Nox4 and the subsequent production of ROS were also reduced by pretreatment with caffeic acid. The expression of α-SMA was prevented by inhibition of ROS generation with siNox4.
  
  
  CONCLUSIONS
  Caffeic acid may inhibit TGF-β1-induced differentiation of fibroblasts into myofibroblasts and collagen production by regulating ROS.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Chung
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Il-Ho
authors.initials: IH
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Sung-Moon
authors.initials: SM
authors.lastname: Hong
authors.affiliation: Department of Medical Science, Korea University Graduate School, Seoul, Korea.
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Cho
authors.affiliation: Department of Medical Science, Korea University Graduate School, Seoul, Korea.
authors.forename: Jun-Hyeok
authors.initials: JH
authors.lastname: Moon
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Seoul, Korea. ; Department of Medical Science, Korea University Graduate School, Seoul, Korea. ; Institute for Medical Devices Clinical Trial Center, Korea University College of Medicine, Seoul, Korea.
authors.forename: Heung-Man
authors.initials: HM
authors.lastname: Lee
keywords: Alpha-smooth muscle actin; Caffeic acid; Collagen; Myofibroblasts; Nasal polyps; Transforming growth factor beta1