Cellular response of mucociliary differentiated primary bronchial epithelial cells to diesel exhaust

Am J Physiol Lung Cell Mol Physiol. 2016 Jul 1;311(1):L111-23. doi: 10.1152/ajplung.00064.2016. Epub 2016 May 17.


Diesel emissions are the main source of air pollution in urban areas, and diesel exposure is linked with substantial adverse health effects. In vitro diesel exposure models are considered a suitable tool for understanding these effects. Here we aimed to use a controlled in vitro exposure system to whole diesel exhaust to study the effect of whole diesel exhaust concentration and exposure duration on mucociliary differentiated human primary bronchial epithelial cells (PBEC). PBEC cultured at the air-liquid interface were exposed for 60 to 375 min to three different dilutions of diesel exhaust (DE). The DE mixture was generated by an engine at 47% load, and characterized for particulate matter size and distribution and chemical and gas composition. Cytotoxicity and epithelial barrier function was assessed, as well as mRNA expression and protein release analysis. DE caused a significant dose-dependent increase in expression of oxidative stress markers (HMOX1 and NQO1; n = 4) at 6 h after 150 min exposure. Furthermore, DE significantly increased the expression of the markers of the integrated stress response CHOP and GADD34 and of the proinflammatory chemokine CXCL8, as well as release of CXCL8 protein. Cytotoxic effects or effects on epithelial barrier function were observed only after prolonged exposures to the highest DE dose. These results demonstrate the suitability of our model and that exposure dose and duration and time of analysis postexposure are main determinants for the effects of DE on differentiated primary human airway epithelial cells.

Keywords: air-liquid interface; airway epithelial cells; diesel exhaust; inflammation; oxidative stress.

MeSH terms

  • Air Pollutants / toxicity*
  • Cell Differentiation
  • Cells, Cultured
  • Endoplasmic Reticulum Stress
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism*
  • Gene Expression
  • Humans
  • Interleukin-8 / metabolism
  • Oxidative Stress
  • Particulate Matter / toxicity*
  • Respiratory Mucosa / drug effects
  • Respiratory Mucosa / metabolism
  • Respiratory Mucosa / pathology
  • Vehicle Emissions / toxicity*


  • Air Pollutants
  • CXCL8 protein, human
  • Interleukin-8
  • Particulate Matter
  • Vehicle Emissions