Skip to main content
. 2013 Sep 27;8(9):e74953. doi: 10.1371/journal.pone.0074953

Figure 1. AhR activation by CSE does not increase COX-2 protein.

Figure 1

AhR−/− and AhR+/+ lung fibroblasts were exposed to CSE or B[a]P (1 µM) for 3, 6 or 24 hours and whole cell lysates collected for protein or RNA analysis. (A) There was a significant increase in Cyp1a1 mRNA in response to both CSE and B[a]P for 6 hours only in AhR+/+ cells (***p<0.0001). Results are expressed as the mean ± SEM of 3–6 independent experiments. (B) Basal levels of CYP1A1 protein were not detectable in primary lung fibroblasts. CYP1A1 was not increased by CSE or the AhR ligand TCDD. MLE-12 cells express basal CYP1A1 that was further increased by B[a]P treatment. Western blot is representative of three experiments. (C) There was significantly more Cyp1b1 mRNA in lung fibroblasts exposed to 1% CSE or B[a]P compared to AhR−/− cells. Results are expressed as the mean ± SEM of 3–8 independent experiments. (D) There is no CYP1B1 protein induction by CSE exposure for 24 hours; note the increase in COX-2 protein only in AhR−/− fibroblasts. B[a]P increased CYP1B1 protein expression in AhR+/+ fibroblasts. Representative western blot is shown.