Fig. 3.

3 Days of butter-flavored e-cig aerosol exposure under sub-ohm conditions decrease viable cell numbers and dysregulate gene expression to a greater extent than under regular vaping conditions. Butter-flavored e-cig aerosols were produced either under sub-ohm or regular vaping conditions and H292 cells were exposed to these aerosols at the air–liquid interface (ALI) for 3 days. a Numbers of viable cells were significantly decreased by the e-cig aerosol produced under sub-ohm vaping conditions. Data are presented as mean ± SEM. Comparisons between groups were made by the student t-test; *p < 0.05: significantly different from the other group. Data are from one experiment representative of results from three independent experiments, each performed in triplicate (n = 3 per group). For each cell insert, bioassays were further evaluated in duplicates. b Heatmap of dysregulated genes reveals that more genes are dysregulated by the e-cig aerosol produced under sub-ohm conditions compared to regular vaping conditions. Data are from H292 cells from distinct experiments. Data are presented as fold-change over the respective air-control group. Fold-changes > ± 1.5 were considered significant. Results from other independent experiments are represented in Additional file 1: Figure S1.