Figure 2

AhR and Arnt differentially regulate CXCL8 and CCL5 responses in 1- NP- or 1- AP- exposed BEAS- 2B cells. Cells were transfected with siRNA against AhR (siAHR) and Arnt (siARNT) or non-targeting control siRNA (siNT), and exposed to 20 μM 1-NP, 1-AP or vehicle (DMSO) alone. CXCL8 (A) and CCL5 (B) gene expression were measured after 6 h by real-time PCR. CXCL8 (C) and CCL5 (D) protein levels in the medium were measured by ELISA after 18 h exposure as described under “Materials and methods”. Efficiency of transfection was assessed by Western blotting (E) as well as expression of CYP1A1 after 6 h exposure to 20 μM B[a]P, 1-NP and 1-AP, by real-time PCR (F). The results are expressed as mean ± SEM (A/B/F: n = 1 (triplicate determinations); C/D: n ≥ 3; E: representative blots, n ≥ 3). *Significantly different from unexposed controls; †Significantly different from cells transfected with non-targeting siRNA.