Effect of Salmeterol and Roflumilast N-oxide (RNO) alone and in combination on gene expression changes in BEAS-2B human airway epithelial cell line

RNA-sequencing was performed to study the effect of phosphodiesterase 4 inhibition by Roflumilast N-oxide (RNO) on gene expression changes produced by sub-maximal concentrations of the long acting β2-adrenoceptor agonist, Salmeterol. Our results indicate that RNO enhanced the expression of all salmeterol-regulated genes, but the degree of enhancement varied between genes due to the difference in their sensitivities to salmeterol. Confluent BEAS-2B cells were treated for two hours with vehicle, RNO (1 µM), a maximal concentration of Salmeterol (100 nM), two sub-maximal concentrations of Salmeterol (0.3 nM and 0.5 nM), and their combination with RNO (Salm0.3 + RNO, Salm0.5 + RNO). Total RNA was extracted, quantified, processed into mRNA libraries, and sequenced across two high-throughput sequencing kits on a NextSeq 500 instrument (Illumina).