Figure 1.

Cigarette smoke extract (CSE) concentration-dependently and time-dependently increases TRPA1 expression in human bronchial epithelial cells (HBECs). (a) Cells were exposed to 0–3% CSE for 24 hours. (b) Cells were incubated with medium alone at time 0 and for 24 hours or exposed to 3% CSE for the indicated times. (c) Cells were exposed to medium alone or exposed to 3% CSE for indicated times. Protein (a and b) and mRNA (c) levels in the cell lysates were analyzed by Western blotting and RT-PCR, respectively. The data in each group are mean ± SEM from five independent experiments. ^∗ p < 0.05 versus the control or versus time zero.