TY - JOUR T1 - Long-acting β<sub>2</sub>-adrenoceptor agonists enhance glucocorticoid receptor (GR)-mediated transcription by gene-specific mechanisms rather than generic effects via GR JF - Molecular Pharmacology JO - Mol Pharmacol DO - 10.1124/mol.118.112755 SP - mol.118.112755 AU - Christopher F Rider AU - Mohammed O Altonsy AU - Mahmoud M Mostafa AU - Suharsh V Shah AU - Sarah Sasse AU - Martijn L Manson AU - Dong Yan AU - Carina Karrman-Mardh AU - Anna Miller-Larsson AU - Anthony N Gerber AU - Mark A Giembycz AU - Robert Newton Y1 - 2018/01/01 UR - http://molpharm.aspetjournals.org/content/early/2018/06/29/mol.118.112755.abstract N2 - In asthma, the clinical efficacy of inhaled corticosteroids (ICSs) is enhanced by long-acting β2-adrenoceptor agonists (LABAs). ICSs, or more accurately, glucocorticoids, promote therapeutically-relevant changes in gene expression and, in primary human bronchial epithelial cells (pHBECs) and airway smooth muscle cells, this genomic effect can be enhanced by a LABA. Modelling this interaction in human bronchial airway epithelial BEAS-2B cells transfected with a 2×glucocorticoid response element (2×GRE)-driven luciferase reporter showed glucocorticoid-induced transcription to be enhanced 2- to 3-fold by LABA. This glucocorticoid receptor (GR; NR3C1)-dependent effect occurred rapidly, was insensitive to protein synthesis inhibition and was maximal when glucocorticoid and LABA were added concurrently. The ability of LABA to enhance GR-mediated transcription was not associated with changes in GR expression, serine (Ser203, Ser211, Ser226) phosphorylation, ligand affinity or nuclear translocation. Chromatin immunoprecipitation demonstrated that glucocorticoid-induced recruitment of GR to the integrated 2×GRE reporter and multiple gene loci, whose mRNAs were unaffected or enhanced by LABA, was also unchanged by LABA. Transcriptomic analysis revealed glucocorticoid-induced mRNAs were variably enhanced, unaffected or repressed by LABA. Thus, events leading to GR binding at target genes is not the primary explanation for how LABAs modulate GR-mediated transcription. As many glucocorticoid-induced genes are independently induced by LABA, gene-specific control by GR- and LABA-activated transcription factors may explain these observations. Since LABAs promote similar effects in pHBECs, therapeutic relevance is likely. These data illustrate the need to understand gene function(s), and the mechanisms leading to gene-specific induction, if existing ICS/LABA combination therapies are to be improved. ER -