Bronchial epithelial cell (NCI-H292) response to cigarette smoke total particulate matter (TPM): Development and utilisation of a simple cell culture model of chronic obstructive pulmonary disease (COPD)
COPD is a complex and multifaceted condition that can be caused by cigarette smoking. In smokers, chronic exposure can lead to the development of COPD specific pathologies such as emphysema, small airway disease and mucus hyper-secretion. On a cellular level these pathologies are driven by an abnormal array of exogenously secreted mediators. Here we describe the development and utilisation of a simple cell culture model in which COPD associated mediators are measured following exposure to TPM.
Methods: Confluent monolayers of human lung epithelial cells (NCI-H292) were prepared and exposed for 24 hours to TPM from University of Kentucky 3R4F reference cigarettes. The cytotoxic (EC50: concentration of TPM that kills 50% of the cells) and secretory response (inflammatory, remodelling and mucin mediators) to TPM exposure were then measured using neutral red uptake, electrochemiluminescence detection (MesoScale Discovery; MSD) and enzyme linked immunosorbent assay (ELISA) respectively. Subsequently, similar measurements were undertaken using TPM derived from Reduced Toxicant Prototypes (RTPs) and their commercial controls.
Results: 3R4F TPM induced a concentration dependent cytotoxic response. At non-cytotoxic concentrations (50 and 10 µg/ml) an increase in the levels of COPD associated mediators were also observed. User variability, assay reproducibility and repeatability were all found to be within acceptable limits. No significant difference in the cytotoxic response was seen following exposure to RTP TPMs, their commercial controls or 3R4F. Further analysis demonstrated a significant effect of both dose and cigarette design on mediator release.
Conclusions: This simple cell culture model is able to discriminate between different cigarette designs and is a suitable model in which to assess lung cell response to cigarette smoke TPM.