title: In vitro cytotoxicity and mutagenicity of mainstream waterpipe smoke and its functional consequences on alveolar type II derived cells.
abstract: BACKGROUND
  While waterpipe tobacco smoking has become a global phenomenon, its potential health consequences are poorly understood. In this manuscript, we report the in vitro mutagenicity of waterpipe smoke condensate (WSC), the alteration in cellular parameters of lung alveolar cells in response to WSC exposure and discuss the implication of cellular responses in the pathophysiology of chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  The mainstream WSC was generated using a standard laboratory machine protocol. We assessed its mutagenicity using Ames test. In addition, we studied the effect of WSC on the proliferation and cell cycle of alveolar type II cells and vascular endothelial cells. We also assessed the effect of WSC on the expression of genes involved in cell cycle arrest and inflammation.
  
  
  RESULTS
  Within the range of tested doses, WSC did not elicit sufficient response to be considered mutagenic in any of the strains tested (TA98, TA100, TA102, and TA97a) but were found to be toxic for strains TA97a and TA102 at the highest tested doses. However, WSC induced cell cycle arrest and cellular senescence mediated by the p53-p21 pathway. Also our study indicated that WSC induced an increase in the transcriptional expression of matrix metalloproteinases, MMP-2 and MMP-9 and an immune response regulator, Toll Like Receptor-4.
  
  
  CONCLUSIONS
  The data reported here represent the first in vitro demonstration of the effect of waterpipe smoke on cellular parameters providing evidence of the potential involvement of WPS in the pathogenesis of COPD through impairing cellular growth and inducing inflammation.
authors.affiliation: Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut 11072020, Lebanon.
authors.forename: Mayyasa
authors.initials: M
authors.lastname: Rammah
authors.forename: Farah
authors.initials: F
authors.lastname: Dandachi
authors.forename: Rola
authors.initials: R
authors.lastname: Salman
authors.forename: Alan
authors.initials: A
authors.lastname: Shihadeh
authors.forename: Marwan
authors.initials: M
authors.lastname: El-Sabban
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016922:Cellular Senescence / Q000187:drug effects; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D020782:Matrix Metalloproteinases / Q000096:biosynthesis; D009152:Mutagenicity Tests; D009153:Mutagens; D009569:Nitric Oxide / Q000032:analysis; D011650:Pulmonary Alveoli / Q000166:cytology / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D012906:Smoke / Q000009:adverse effects; D051197:Toll-Like Receptor 4 / Q000096:biosynthesis; D014026:Nicotiana
chemical_list: D009153:Mutagens; D012906:Smoke; D051197:Toll-Like Receptor 4; D009569:Nitric Oxide; D020782:Matrix Metalloproteinases