Fig. 3

Differentiated primary human bAEC exposed to WFSE exhibit a fragile epithelial phenotype Trans-epithelial electrical resistance (TEER; ionic conductance of the paracellular pathway) and passage of sodium fluorescein tracers (paracellular molecular flow) were quantified for primary bronchial airway epithelial cells that were differentiated in a transwell culture system. a A reduction in electrical impedance (vs. the control exposure) is evident for the 2.5–10% wildfire smoke extract (WFSE) treatments after the 6 h exposure interval (left graphic). This relationship is maintained after 24 h (right graphic) when the maximum reduction in electrical resistance is observed for 5–10% WFSE, and the effect of 10% cigarette smoke extract (10% CSE) exceeds 2.5% WFSE. b The passage of sodium fluorescein tracers from the apical to the basal reservoir is evident for the 5 and 10% WFSE exposures at the 6 h interval (left graphic). At the 24 h interval the influence of 5–10% WFSE potentiates a marked increase in paracellular molecular flow, and are followed by 10% CSE treatment. Data is representative of n = 3 cultures from different individuals. Intervals are SE. For clarity “*” were omitted from these graphics, and P values are reported in Additional file 3: Table S1