title: [Effects of cyclic stretch on the induction of the transdifferentiation in human lung epithelial cells].
abstract: OBJECTIVE
  To investigate the effect of mechanical stretch induced epithelial-mesenchymal transition in human lung epithelial cells BEAS-2B in vitro.
  
  
  METHODS
  The human lung epithelial cells BEAS-2B were subjected to cyclic stretch by the FX-5000T system at 0.33 Hz of 10% or 20% elongation for 24, 48 and 72 hours respectively. The morphologic changes were observed by microscopy. The mRNA and protein expressions of E-cadherin, Cytokeratin-8 (CK-8), α-smooth muscle actin (α-SMA) and Vimentin were evaluated by immunofluorescence before and after mechanical stretch and fluorescent quantitation reverse transcription-polymerase chain reaction (qRT-PCR).
  
  
  RESULTS
  (1) When stretch by 20% elongation for 48 hours, the morphological changes in BEAS-2B cells from cobblestone-like structure to elongated shape and obviously when stretch for up to 72 hours, while 10% elongation showed no significant morphological changes comparing to control. (2) Decreasing E-cadherin and CK-8 protein expression was associated with increased immunostaining for α-SMA protein at 72 hours after 20% mechanical stretch. (3) Expression of E-cadherin mRNA was decreased to 0.388±0.056 and 0.247±0.064 after 20% mechanical stretch for 48 hours and 72 hours compared with control without stretch (set 1, both P<0.05), expression of CK-8 mRNA was decreased to 0.436±0.060 at 72 hours after 20% mechanical stretch (P<0.01), α-SMA mRNA was increased to 1.437±0.267 (48 hours) and 1.261±0.247 (72 hours) after 20% mechanical stretch (both P<0.05), and Vimentin mRNA was increased to 1.679±0.172 (48 hours) after 20% mechanical stretch (P<0.05). Expression of E-cadherin mRNA was decreased to 0.387±0.081 at 72 hours after 10% mechanical stretch (P<0.05), Vimentin mRNA was increased to 1.688±0.179 at 48 hours after 10% mechanical stretch while other markers showed no significant changes comparing with control.
  
  
  CONCLUSIONS
  Excessive mechanical stretch could induce epithelial-mesenchymal transition in lung epithelial cells BEAS-2B in vitro.
authors.affiliation: The First Affiliated Hospital of Guangzhou Medical Collage, Guangzhou Institute of Respiratory Disease, Guangzhou 510120, Guangdong, China. Corresponding author: Li Yi-min, Email: dryiminli@vip.163.com.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.forename: Pu
authors.initials: P
authors.lastname: Mao
authors.forename: Wei
authors.initials: W
authors.lastname: Fu
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Pang
authors.forename: Yin-yan
authors.initials: YY
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.forename: Wei-qun
authors.initials: WQ
authors.lastname: He
authors.forename: Xiao-qing
authors.initials: XQ
authors.lastname: Liu
authors.forename: Yi-min
authors.initials: YM
authors.lastname: Li
mesh_terms: D000199:Actins / Q000378:metabolism; D015703:Antigens, CD; D001696:Biomechanical Phenomena; D015820:Cadherins / Q000378:metabolism; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology*; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D053533:Keratin-8 / Q000378:metabolism; D008168:Lung / Q000166:cytology*; D013314:Stress, Mechanical
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; D053533:Keratin-8