Title | Modulation of transcriptional responses by poly(I:C) and human rhinovirus: effect of long-acting beta(2)-adrenoceptor agonists. | ||
Author | Rider, Christopher F; Miller-Larsson, Anna; Proud, David; Giembycz, Mark A; Newton, Robert | ||
Journal | Eur J Pharmacol | Publication Year/Month | 2013-May |
PMID | 23523474 | PMCID | -N/A- |
Affiliation | 1.Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, 3330 Hospital Drive NW, AB, Canada T2N 4N1. cfrider@ucalgary.ca. |
Exacerbations of asthma, a chronic inflammatory respiratory disease, are associated with viral upper respiratory tract infections involving human rhinovirus. Although glucocorticoids (corticosteroids) effectively control airways inflammation in many asthmatics, human rhinovirus-associated exacerbations show reduced glucocorticoid responsiveness. Using human bronchial epithelial BEAS-2B cells, we show that human rhinovirus reduced glucocorticoid-inducible activation of glucocorticoid response element (GRE) reporter systems in a time- and concentration-dependent manner. The synthetic double-stranded viral RNA mimetic, polyinosinic:polycytidylic acid (poly(I:C)), also reduced activation of GRE reporter systems in BEAS-2B and pulmonary A549 cells. In addition, poly(I:C) decreased transcription from cAMP response element (CRE)-, TATA-, simian virus 40- and nuclear factor-kappa B (NF-kappaB)-dependent reporter systems. The effects of poly(I:C) on GRE-reporter activation were countered by the long-acting beta2-adrenoceptor agonists, formoterol and salmeterol. Likewise, increased expression of the gene cyclin-dependent kinase inhibitor 1C (CDKN1C; p57(KIP2)) by dexamethasone was reduced by poly(I:C), but was substantially enhanced by the addition of formoterol. Poly(I:C) induced the expression of interleukin-8 (IL8; CXCL8) and this was significantly decreased by dexamethasone, formoterol or their combination. This confirms that not all transcriptional responses were attenuated by poly(I:C) and that decreased glucocorticoid-dependent transcription can be counteracted by the addition of long-acting beta2-adrenoceptor agonists. These data show how human rhinovirus may attenuate glucocorticoid-induced transcription to reduce anti-inflammatory activity. However, addition of long-acting beta2-adrenoceptor agonist to the glucocorticoid functionally restored this response and shows how glucocorticoid plus long-acting beta2-adrenoceptor agonist combinations may prove beneficial during virus-induced exacerbations of asthma.