Chrysotile Causes Human Bronchial Epithelial Cell Apoptosis in Response to the Fas-Mediated Apoptosis Pathway

Pathobiology. 2017;84(5):229-236. doi: 10.1159/000455902. Epub 2017 Sep 13.

Abstract

Aims: Asbestos is harmful to human health. However, the pathogenicity of chrysotile is a controversial matter. This study aimed to investigate the apoptosis of a human bronchial epithelial cell line (BEAS-2B) exposed to chrysotile that may function in part through the Fas death receptor pathway.

Methods: Cultured human BEAS-2B cells were treated with chrysotile and cell viability was evaluated by CCK-8 assay. The induction of cell apoptosis was evaluated by FACS analysis. mRNA expression levels of Fas, caspase-3, and caspase-8 were evaluated quantitatively by real-time PCR. The expression of Fas, caspase-3, and caspase-8 proteins were evaluated by Western blot. Meanwhile, cells were preincubated with various concentrations of anti-Fas antibody (CH11) and antagonistic anti-Fas antibody (ZB4).

Results: Chrysotile inhibits proliferation, induces apoptosis, and upregulates the expression of Fas, caspase-3, and caspase-8. The role of Fas as a regulator of chrysotile-induced apoptosis in BEAS-2B cells was tested by the prominent increase in and partial blockade of the apoptotic rate with CH11 and ZB4. When CH11 was pretreated, a synergistic effect was apparent on chrysotile-induced apoptosis and the mRNA and protein expression levels of Fas and cleaved caspase-3.

Conclusion: Chrysotile causes the apoptosis of BEAS-2B cells via the Fas death receptor pathway. The Fas-mediated apoptosis pathway plays an important role in chrysotile-induced apoptosis of BEAS-2B cells in vitro.

Keywords: Apoptosis; Cytotoxicity; Mineral fibers.

MeSH terms

  • Apoptosis / drug effects*
  • Asbestos, Serpentine / pharmacology*
  • Asbestos, Serpentine / toxicity
  • Blotting, Western
  • Bronchi / cytology
  • Bronchi / drug effects*
  • Caspase 3 / drug effects
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Caspase 8 / drug effects
  • Caspase 8 / genetics
  • Caspase 8 / metabolism
  • Cell Line
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects*
  • Dose-Response Relationship, Drug
  • Epithelial Cells / drug effects*
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Humans
  • Up-Regulation / drug effects
  • fas Receptor / genetics
  • fas Receptor / immunology
  • fas Receptor / metabolism

Substances

  • Asbestos, Serpentine
  • fas Receptor
  • CASP3 protein, human
  • Caspase 3
  • Caspase 8