TY - JOUR T1 - Disease and cell type specific glucocorticoid receptor-isoform expression and re-synthesis in asthma JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2019.PA4212 VL - 54 IS - suppl 63 SP - PA4212 AU - Liang Zhou AU - Lei Fang AU - Michael Roth AU - Michael Tamm AU - Daiana Stolz Y1 - 2019/09/28 UR - http://erj.ersjournals.com/content/54/suppl_63/PA4212.abstract N2 - Background: Two cytosolic glucocorticoid receptors (GR-α, GR-β) derive from the same mRNA. Steroids translocate both into the nucleus, where they bind to a specific DNA sequence. GR-α regulates gene activity, while GR-β prevents GR-α from binding. After activation the human GR is degraded and needs re-synthesis. Thus, reduced steroid-response can either be caused by high GR-β or reduced re-synthesis.Aim: Comparing the ratio, re-synthesis and activation of GR-isoforms in primary human airway smooth muscle cells (ASMC) and epithelial cells (AEC) from controls (n=6) with asthma patients (n=8).Methods: GR-isoform expression was determined by Western-blotting, re-synthesis by quantitative real time PCR, and GR translocation by immune-fluorescence microscopy.Results: In AEC and ASMC of asthma patients compared to controls, total GR and GR-bexpression was comparable, while GR-awas significantly reduced in asthmatic ASMC. Thus, shifting the ratio to GR-b> GR-ain asthmatic ASMC. Steroids (budesonide, fluticasone, or dexamethasone, 10 nM) shifted both GR-isoforms into the nucleus within 15 minutes, lasting over 6 hours, and declining afterwards. No disease or steroid specific difference of the GR activation-kinetic was observed. 24 hours after steroid exposure the GR protein was reduced in all ASMC in a concentration-dependent manner, reaching significance in asthmatic, but not control ASMC. However, the a:b-ratio was not affected. GR re-synthesis was significantly reduced in asthmatic ASMC, while it was stable in control ASMC.Conclusion: GR-aexpression and re-synthesis was significantly reduced in asthmatic ASMC compared to controls. This might explain low steroid-response in severe asthma.FootnotesCite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA4212.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -