Figure 2.

PG/VG aerosols cause ion channel dysfunction. (A) Study design for in vitro exposures of primary HBEC to e-cig aerosols of PG/VG. CBF ciliary beat frequency, UC Ussing chamber, qPCR quantitative PCR, IF immunofluorescence staining. (B) Representative tracing of short-circuit current (I_SC) measurements in Ussing chambers with a basolateral-to-apical Cl⁻ gradient following forskolin stimulation and CFTR inhibition by CFTR_inh-172 in the presence of amiloride in fully differentiated HBEC exposed to air (control) or e-cig aerosols of PG/VG. (C) CFTR conductance as measured by ∆I_SC following CFTR_inh-172 in HBEC exposed to air or PG/VG aerosols for seven days. n = 11 ALI cultures from 11 donors. (D) ENaC conductance as measured by ∆I_SC following amiloride in HBEC exposed to air or PG/VG aerosols for seven days. n = 9 ALI cultures from 9 donors. (E) Representative tracing of I_SC measurements in Ussing chambers with a basolateral-to-apical K⁺ gradient following ATP stimulation in the presence of amiloride in fully differentiated HBEC exposed to air or e-cig aerosols of PG/VG. (F) BK conductance as measured by ∆I_SC following ATP in HBEC exposed to air or PG/VG aerosols for seven days. n = 8 ALI cultures from 8 donors. (G) Quantification of ciliary beat frequency (CBF) from whole field analysis in HBEC exposed to air or PG/VG aerosols for five days. n = 8 ALI cultures from 4 donors (represented by different shapes), which were sampled 5 times each, resulting in 40 datapoints included in the permutation analysis and shown in the figure. Statistics: Data shown as median (line), 25th to 75th percentiles (box), and minimum to maximum values (whiskers). *p < 0.05, Wilcoxon test (C, D and F) or LMM permutation test (G).