title: Store-operated Ca2+ entry is involved in transforming growth factor-β1 facilitated proliferation of rat airway smooth muscle cells.
abstract: OBJECTIVE
  To investigate the role and underlying mechanisms of store-operated Ca(2+) entry (SOCE) in mediating the promoting effect of transforming growth factor (TGF)-β1 on the proliferation of airway smooth muscle cells (ASMCs).
  
  
  METHODS
  Rat bronchial smooth muscle cells were cultured as we described previously. The intracellular Ca(2+) concentration ([Ca(2+)]i) of ASMCs was measured by laser confocal microscope Ca(2+) fluorescence imaging with Fluo-3/AM. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and p27 expression assay were used to determine the proliferation rate of ASMCs.
  
  
  RESULTS
  We demonstrated that TGF-β1 (10 ng/ml) increased basal (Ca(2+)]i) level, [Ca(2+)]i rise induced by thapsigargin-induced Ca(2+) release and SOCE in rat ASMCs. This effect of TGF-β1 on SOCE was not inhibited by glucocorticoid dexamethasone (DXM, 100 nM), antioxidant α-tocopherol (100 μM), and intermediate-conductance Ca(2+)-activated K(+) channels (IKCa) inhibitor charybdotoxin (100 nM), suggesting that reactive oxygen species and IKCa channels might not mediate the effect of TGF-β1. TGF-β1 slightly increased the expression of Orai1 and STIM1, two important molecules involved in the molecule component and regulation of SOC channels, in the presence of 10% fetal bovine serum (FBS). The proliferation of ASMC stimulated with 2.5% FBS was promoted by TGF-β1, and partly inhibited by non-specific Ca(2+) channel blocker SKF-96365 (10 μM) and Ni(2+) (100 μM). DXM, α-tocopherol, and charybdotoxin had no effect on the proliferation promoted by TGF-β1.
  
  
  CONCLUSIONS
  TGF-β1 promotes ASMC proliferation partly through increasing the expression and activity of SOC channels.
authors: Department of Respiratory Medicine, Zhongnan Hospital, Wuhan University, Wuhan, China. gaoyadong@gmail.com
authors: Ya-Dong
authors: YD
authors: Gao
authors: Jun-Wen
authors: JW
authors: Zheng
authors: Ping
authors: P
authors: Li
authors: Ming
authors: M
authors: Cheng
authors: Jiong
authors: J
authors: Yang
mesh_terms: D000818:Animals; D001980:Bronchi / Q000166:cytology / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000032:analysis; D049109:Cell Proliferation / Q000187:drug effects*; D003907:Dexamethasone / Q000494:pharmacology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D000071740:ORAI1 Protein; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071737:Stromal Interaction Molecule 1; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D008562:Membrane Glycoproteins; D000071740:ORAI1 Protein; C532493:Orai1 protein, rat; D024681:Potassium Channels, Calcium-Activated; C518857:Stim1 protein, rat; D000071737:Stromal Interaction Molecule 1; D053773:Transforming Growth Factor beta1; D014810:Vitamin E; D003907:Dexamethasone; D002118:Calcium