title: [Role of calcineurin-nuclear factor of activated T cells signaling pathway in myoblast apoptosis induced by cyclic tensile strain].
abstract: OBJECTIVE
  This study investigated the role and mechanism of calcineurin (CaN)-nuclear factor of activated T cells (NFAT) pathway in the myoblast apoptosis induced by cyclic tensile strain.
  
  
  METHODS
  Myoblasts were cultured using an in vitro-mechanical stimulation model and imposed with tension for different hours with a multi-channel cell stress loading system. Cyclosporine (CsA) was used as CaN inhibitor to clarify the role of CaN in the apoptosis induced by cyclic stress. Hochest 33258 staining and flow cytometry detection were performed to detect the apoptotic cells. Real-time polymerase chain reaction was conducted to detect the mRNA expression of CaN and NFAT. Protein levels of NFAT3 were evaluated by Western blot.
  
  
  RESULTS
  The apoptosis rate increased with the extension of loading time. The mRNA expression of the CaN subunits, CnA and CnB, and the protein levels of NFAT3 also increased. When the myoblasts were incubated with CsA, the apoptosis rate decreased, the mRNA expression of CnA and NFAT3 significantly decreased, and the NFAT3 protein expression levels became significantly lower than those of the groups without CsA.
  
  
  CONCLUSIONS
  Continuous cyclic tensile stress can induce myoblast apoptosis. The CaN-NFAT signaling pathway may be involved in the cyclic stretch-induced apoptosis of myoblasts.
authors.forename: Xian
authors.initials: X
authors.lastname: Ding
authors.forename: Chenlei
authors.initials: C
authors.lastname: Xia
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.forename: Wenna
authors.initials: W
authors.lastname: Sun
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Wenxin
authors.initials: W
authors.lastname: Jiang
authors.forename: Caixia
authors.initials: C
authors.lastname: Zhang
authors.forename: Shuangyu
authors.initials: S
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ruyong
authors.initials: R
authors.lastname: Yao
authors.forename: Xiao
authors.initials: X
authors.lastname: Yuan
mesh_terms: D017209:Apoptosis; D019703:Calcineurin / Q000235:genetics*; D016572:Cyclosporine; D005434:Flow Cytometry; D032446:Myoblasts / Q000502:physiology*; D050778:NFATC Transcription Factors / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D013601:T-Lymphocytes
chemical_list: D050778:NFATC Transcription Factors; D016572:Cyclosporine; D019703:Calcineurin