Figure 4.

TRPA1 inhibition partially reduced MUC5AC induction and pine particulate matter (PM) cytotoxicity. Effect of the TRPA1 antagonist, A967079 (A96; 20 μM) on (A) 20 μg/cm² pine WSPM- and (B) 250 μM coniferaldehyde-induced MUC5AC expression in HLBECs. MUC5AC expression was normalized to pine WSPM or coniferaldehyde treatment. C, Effect of A967079 on cell viability of HLBECs in the presence (circles) and absence (squares) of pine WSPM (20 μg/cm²). Cell viability for pine only treatment is shown as the dotted line. Data are normalized to vehicle only treatment (ie, 100% residual viability). Data are presented as the mean ± SEM from n ≥ 3 replicates. *p < .05. In (C), black-filled circles and squares indicate ***p < .001.