title: Fibroblast-epithelial cell interactions drive epithelial-mesenchymal transition differently in cells from normal and COPD patients.
abstract: BACKGROUND
  Epithelial-to-mesenchymal transition (EMT), which involves changes in cellular morphology of highly polarized epithelial cells and the gain of mesenchymal cell phenotype with migratory and invasive capacities, is implicated in smoking-related chronic obstructive pulmonary disease (COPD). However, the interactions of fibroblasts and epithelial cells and the participation of fibroblasts in the EMT processes in COPD are poorly understood. Here, we investigated the hypothesis that EMT is active in human bronchial epithelial (HBE) cells of COPD patients, and that mediators secreted by lung fibroblasts from COPD patients induce EMT.
  
  
  METHODS
  Primary HBE cells from normal subjects and COPD patients were purchased from LONZA. HLFs were derived from resected lung obtained from normal (N) and COPD (D) subjects and their conditioned medium (CM) was collected after 2-day culture in serum-free medium. The expression of epithelial and mesenchymal markers as well as EMT-related transcription factors in lung biopsies, and in HBE cells following stimulation with CM from both normal human lung fibroblasts (NHLF) and COPD human lung fibroblasts (DHLF) was evaluated by immunohistochemistry, qRT-PCR and western blot.
  
  
  RESULTS
  Basal mRNA expression of mesenchymal markers and EMT-related transcription factors were increased in DHBE cells compared to normal human bronchial epithelial cells (NHBE) cells as well as in COPD lungs. CM from NHLF significantly induced vimentin expression in both NHBE and COPD human bronchial epithelial cells (DHBE) cells, but only increased N-cadherin expression in DHBE cells. CM from NHLF significantly induced Twist1 and Twist2 expression in NHBE cells and increased Snai2 (Slug) expression in DHBE cells. While CM from NHLF had no effect on such EMT markers, CM from DHLF significantly increased the protein expression of E-cadherin and vimentin in NHBE cells compared to control. N-cadherin expression was upregulated to a greater degree in NHBE cells than DHBE cells. Only CM from DHLF significantly increased E-/N-cadherin ratio in DHBE cells.
  
  
  CONCLUSIONS
  Our results suggest that DHBE cells have partially undergone EMT under baseline conditions. DHLF-CM promoted EMT in NHBE, suggesting that interactions between fibroblast and epithelial cells may play an important role in the EMT process in COPD.
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. michiyoshi117@gmail.com.
authors.forename: Michiyoshi
authors.initials: M
authors.lastname: Nishioka
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. venkinaryan@yahoo.com.
authors.forename: Narayanan
authors.initials: N
authors.lastname: Venkatesan
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. kevin.dessalle@gmail.com.
authors.forename: Kevin
authors.initials: K
authors.lastname: Dessalle
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. andrea.mogas@mail.mcgill.ca.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mogas
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. shigekyoh@gmail.com.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kyoh
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. yuebaoyuebao@gmail.com.|Department of Thoracic Medicine, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Taipei, Taiwan. yuebaoyuebao@gmail.com.
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Department of Medicine, McMaster University, Hamilton, ON, Canada. parames@mcmaster.ca.
authors.forename: Parameswaran
authors.initials: P
authors.lastname: Nair
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. carolyn.baglole@mcgill.ca.
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Baglole
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. david.eidelman@mcgill.ca.
authors.forename: David H
authors.initials: DH
authors.lastname: Eidelman
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. mara.ludwig@mcgill.ca.
authors.forename: Mara S
authors.initials: MS
authors.lastname: Ludwig
authors.affiliation: Meakins-Christie Laboratories, Research Institute-McGill University Health Centre, 1001 Decarie Boulevard, Block E, Montreal, QC, H4A 3J1, Canada. qutayba.hamid@mcgill.ca.
authors.forename: Qutayba
authors.initials: Q
authors.lastname: Hamid
mesh_terms: D002450:Cell Communication / Q000502:physiology*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000473:pathology; D020545:Respiratory Mucosa / Q000378:metabolism / Q000473:pathology