title: [Chrysotile fibers induced apoptosis of human bronchial epithelial cells and effect of oxidation].
abstract: OBJECTIVE
  To investigate the apoptosis rate and the reactive oxygen species (ROS) level induced by chrysotile fibers in BEAS-2B cells and the blockage effect of free radical scavengers on the induction of chrysotile fibers.
  
  
  METHODS
  The cell survival rate, the morphological variation of BEAS-2B cells, the apoptosis rate, the expression levels of gene caspase-3 and the ROS generation level were measured by using trypan blue phagocytosis, hematoxylin and eosin staining, oligonucleosomal DNA fragmentation assay, FCM, RT-PCR and fluorescent probe DCFH-DA in the suspension (0, 5, 10, 20, 100 and 200 microg/cm(2)) and the filtrate (0, 100, 200, 400, 800 and 1600 microg/ml) of chrysotile fibers. Addition of free radical scavengers such as catalase, dimethyl sulfoxide and mannitol prevented the radical generation and gene expression.
  
  
  RESULTS
  Survival rates of BEAS2B cells treated by the suspension (0, 5 and 10 microg/cm(2)) and the filtrate (0, 100 and 200 microg/ml) of chrysotile fibers for 24 hours were above 90%. The apoptotic rates of BEAS-2B were increased with the concentration of suspension and filtrate from chrysotile fibers (P < 0.05). Otherwise, caspase-3 mRNA and ROS were stimulated by chrysotile fibers. Free radical scavengers such as CAT, DMSO and mannitol could reduce these stimulations. The ROS blocking rate of suspension of chrysotile fibers was 23.7%, 21.6% and 11.2% respectively, and that of filtrate was 37.9%, 40.3% and 10.6% respectively.
  
  
  CONCLUSIONS
  Apoptosis is induced in BEAS-2B cells exposed to chrysotile fibers suspension and filtrate. Generation of ROS plays an important role in chrysotile fibers-induced BEAS-2B cell apoptosis.
authors.affiliation: Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Li-jin
authors.initials: LJ
authors.lastname: Zhu
authors.forename: Zhen-yu
authors.initials: ZY
authors.lastname: Jia
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiao
authors.forename: Li
authors.initials: L
authors.lastname: Ju
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D017632:Asbestos, Serpentine / Q000633:toxicity*; D002460:Cell Line; D004336:Drug Antagonism; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017632:Asbestos, Serpentine; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species