title: Effect of tetrandrine on the TGF-β-induced smad signal transduction pathway in human hypertrophic scar fibroblasts in vitro.
abstract: OBJECTIVE
  To evaluate in vitro effects of tetrandrine on the TGF-β-induced smad signal transduction pathway and cellular function altered by tetrandrine in human hypertrophic scar fibroblasts (HSFs).
  
  
  METHODS
  HSFs were exposed to four different treatments (control, tetrandrine, TGF-β(1) and mixture). After 48 h culture, expression of TGF-β1, Smad2 and Smad7 were examined using reverse transcription PCR and Western blotting. To evaluate cellular function alteration, morphological changes of HSFs were observed under an inverted microscope, expression of type I and III collagen were tested by immunocytochemistry, and cell cycles were analyzed by flow cytometry.
  
  
  RESULTS
  Expression of Smad7 increased while expression of Smad2 and TGF-β1 mRNA decreased in HSFs with tetrandrine. In addition, type I and III collagen was suppressed and S phase of the cell cycle markedly shortened in HSFs by tetrandrine.
  
  
  CONCLUSIONS
  These results suggest that tetrandrine inhibits HSFs at least partially through induction of Smad7 and decrement of Smad2 resulting in inhibition of TGF-β1 transcription and its intracellular signaling, which led to reduction of type I and III collagen production and suppression of cell reproductive activity.
authors.affiliation: Anatomy Department of Southern Medical University, Guangzhou, Guangdong Province, China. Linzunwen83@126.com
authors.forename: Lin
authors.initials: L
authors.lastname: Zunwen
authors.forename: Zhong
authors.initials: Z
authors.lastname: Shizhen
authors.forename: Liu
authors.initials: L
authors.lastname: Dewu
authors.forename: Mao
authors.initials: M
authors.lastname: Yungui
authors.forename: Ning
authors.initials: N
authors.lastname: Pu
mesh_terms: D044182:Benzylisoquinolines / Q000494:pharmacology*; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017439:Cicatrix, Hypertrophic / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D051899:Smad2 Protein / Q000378:metabolism*; D051906:Smad7 Protein / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D044182:Benzylisoquinolines; D007166:Immunosuppressive Agents; D012333:RNA, Messenger; C497782:SMAD2 protein, human; C497806:SMAD7 protein, human; D051899:Smad2 Protein; D051906:Smad7 Protein; D016212:Transforming Growth Factor beta; C009438:tetrandrine