Effects of oxygen concentration and exposure time on cultured human airway epithelial cells.
OBJECTIVE
To distinguish the direct effects of oxygen dose and exposure time on human airway epithelial cells. We hypothesized that progressive oxygen exposure would induce cell dysfunction and inflammation in a dose-dependent manner.


METHODS
Interventional laboratory study.


METHODS
An academic medical research facility in the northeastern United States.


METHODS
Calu-3 human airway epithelial cell culture.


METHODS
Cells were cultured at a gas-liquid interface with the cells fed basolaterally with medium and grown to full confluence. The apical surfaces were then exposed to gas containing 21%, 40%, 60%, or 80% oxygen, 5% CO2, and balance nitrogen for 24 or 72 hrs.


RESULTS
The effects of oxygen concentration and time-induced cellular change were examined by measuring transepithelial resistance of monolayers, cell viability by trypan blue exclusion, basolateral lactate concentration, histology of monolayer cross-sections, and cytospin slides, plus interleukin (IL)-6 and IL-8 secretion in apical surface fluid. Transepithelial resistance decreased in a dose- and time-dependent manner (p < .001), whereas cell viability was reduced only at 72 hrs and in all hyperoxic groups (p < .05). IL-6 secretion was elevated in all hyperoxic groups at 24 hrs (p < .001), and both IL-6 and IL-8 levels were greater in the 40% FiO2 group compared with all other groups at 72 hrs (p < .01).


CONCLUSIONS
In this model, airway epithelial cells demonstrate profound concentration and time-dependent responses to hyperoxic exposure with respect to cell physiology, viability, histology, and secretion of inflammatory mediators. This model might be a valuable tool for preliminary analysis of potentially protective therapies against hyperoxia-induced airway epithelial injury.
Zhu
Yan
Y
Nemours Research Lung Center, Nemours, Alfred I. duPont Hospital for Children, Wilmington, DE, USA. yzhu@nemours.org
Miller
Thomas L
TL
Singhaus
Clifford J
CJ
Shaffer
Thomas H
TH
Chidekel
Aaron
A
D018929:Cell Culture Techniques / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D009511:New England; D010100:Oxygen / Q000008:administration & dosage* / Q000276:immunology* / Q000378:metabolism; D020545:Respiratory Mucosa / Q000276:immunology*; D013997:Time Factors
D010100:Oxygen