title: Effects of tanshinone IIA on the transforming growth factor β1/Smad signaling pathway in rat cardiac fibroblasts.
abstract: OBJECTIVE
  This study explores the mechanism of tanshinone IIA (TSN)-mediated inhibition of myocardial fibrosis by investigating the effect of TSN on transforming growth factor β1 (TGFβ1) signal transduction in rat cardiac fibroblasts (CFs).
  
  
  METHODS
  CFs were isolated from neonatal Sprague-Dawley rats by trypsin digestion and differential adhesion and stimulated with 5 ng/mL TGFβ1 and TSN (10(-6), 10(-5), or 10(-4) mol/L). The expression of fibronectin (FN) mRNA in the CFs was determined using reverse transcriptase-polymerase chain reaction and the protein expression of FN and Smads in CFs was detected using Western blot. The intracellular expression and localization of Smads in the CFs were analyzed using immunocytochemistry.
  
  
  RESULTS
  TGFβ1 induced the expression of FN and Smads in a time-dependent manner. At the end of the culture treatment, the mRNA expression of FN and the expression of phosphorylated Smad2/3 (p-Smad2/3) increased significantly (P < 0.01). TSN pretreatment (10(-5) and 10(-4) mol/L) reduced the expression of FN and p-Smad2/3 (P < 0.01) following TGFβ1 stimulation and led to a significant decrease in the nuclear staining intensity and a positive rate of p-Smad2/3 (P < 0.05 and P < 0.01, respectively).
  
  
  CONCLUSIONS
  The inhibitory effect of TSN on myocardial fibrosis may be associated with its inhibition of TGFβ1-induced Smad2/3 phosphorylation and p-Smad2/3 nuclear translocation, which blocks the TGFβ1/Smad signaling pathway in CFs.
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Cheng-Ye
authors.initials: CY
authors.lastname: Zhan
authors.affiliation: Department of Paediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Tang
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Dai-Xing
authors.initials: DX
authors.lastname: Zhou
authors.affiliation: Department of Emergency Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Li
mesh_terms: D045784:Abietanes / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000166:cytology; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
chemical_list: D045784:Abietanes; D005353:Fibronectins; D012333:RNA, Messenger; D051785:Smad Proteins; D053773:Transforming Growth Factor beta1; C021751:tanshinone
keywords: Cardiac fibroblasts; smads; tanshinone II A; transforming growth factor β1