title: [Bone morphogenetic protein 4 increases canonical transient receptor potential protein expression by activating bone morphogenetic protein receptor Ⅱ/Smad signaling pathways in pulmonary arterial smooth muscle cells].
abstract: OBJECTIVE
  To observe the effect of bone morphogenetic protein 4 (BMP4) on the Smad signaling pathway in rat distal pulmonary artery smooth muscle cells (PASMCs), and to explore the role of the transient receptor potential ion channel (TRPC) protein 1 and 6(TRPC1, 6) in rat distal PASMCs.
  
  
  METHODS
  Distal pulmonary arteries were isolated from adult male Wistar rats(n=6, 280-300 g). The endothelium-denuded pulmonary artery tissue was digested using Collagenase and PASMCs were cultured. Activation of BMP4 signaling pathway in Smad was detected by Western blotting. Western blotting was used for the measurement of protein to determine the involvement of BMP4/BMPRⅡ signaling in BMP4-inducd TRPC1 and TRPC6 protein expression, and Smad signaling was inhibited by the specific BMPRⅡ small interfering RNA (BMPRⅡSiRNA).
  
  
  RESULTS
  Rapid phosphorylation of Smad1/5/8 was seen after 15 min of stimulation with BMP4, which was reduced with time. The BMPR Ⅱ proteins was effectively down-regulated in the PASMCs after transfection with BMPRⅡ SiRNA, and the phosphorylation of Smad1/5/8 BMP4-induced was decreased in the PASMCs transfected with BMPR Ⅱ SiRNA compared to the normal PASMCs. In addition, transfection of BMPRⅡsiRNA also attenuated BMP4-induced TRPC1 and TRPC6 protein expression compared with transfection of NT-target siRNA in distal PASMCs. PASMCs transfected with BMPRⅡsiRNA showed a markedly decreased ability for BMP4 induction as assessed by gray value ratio of Western blotting, 2.7 times and 2.5 times by TRPC1/β-actin and TRPC6/β-actin respectively, compared with NT siRNA-treated cells(P<0.05).
  
  
  CONCLUSIONS
  TRPC1 and TRPC6 protein expression can be up-regulated through Smad1/5/8 signaling activation by combination of BMP4 and BMPRⅡ in PASMCs.
authors.affiliation: Department of Respiratory Medicine, Guangzhou First People's Hospital, Guangzhou 510180, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Li
authors.forename: P X
authors.initials: PX
authors.lastname: Ran
authors.forename: J
authors.initials: J
authors.lastname: Wang
mesh_terms: D000199:Actins; D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000378:metabolism*; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000378:metabolism*; D015870:Gene Expression; D005786:Gene Expression Regulation; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D010766:Phosphorylation; D011651:Pulmonary Artery / Q000166:cytology; D034741:RNA, Small Interfering; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D051785:Smad Proteins / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000199:Actins; C525811:Bmp4 protein, rat; D055415:Bone Morphogenetic Protein 4; D034741:RNA, Small Interfering; D051785:Smad Proteins; D050052:TRPC Cation Channels; C492145:Trpc6 protein, rat; C096351:transient receptor potential cation channel, subfamily C, member 1; D052006:Bone Morphogenetic Protein Receptors, Type II