TY - JOUR T1 - Proteome profiling reveals candidate mediators of TGF-β-induced glucocorticoid resistance JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2015.PA3575 VL - 46 IS - suppl 59 SP - PA3575 AU - Meina Li AU - Christine Keenan AU - Yuxiu Xia AU - Alastair Stewart Y1 - 2015/09/01 UR - http://erj.ersjournals.com/content/46/suppl_59/PA3575.abstract N2 - Background: Intrinsic or acquired resistance to Glucocorticoids (GCs) limits their effectiveness. Transforming growth factor-β1 (TGF-β1) induces GC insensitivity in epithelial cell lines and differentiated air-liquid interface (ALI) human primary epithelial cells (Keenan et al. Respir Res 2014; 15:55). TGF-βreceptor (ALK5) inhibition prevents TGF-β1 impairment of GC transactivation, but the relevant signal transduction pathways downstream of ALK5 are not known.Methods: The effects of TGF-βisoforms on the inhibition of different TGF-β1 signaling pathways in human bronchial epithelial cells, BEAS-2B were measured using a GC Response Element (GRE)-Secreted embryonic alkaline phosphatase (SEAP) reporter and by measuring GC-inducible gene expression by qRT-PCR. Proteomic response of BEAS-2B to TGF-β1 was analyzed by differential in-gel electrophoresis (2D DIGE) and liquid chromatography tandem mass spectrometry (LC-MS/MS).Differentially expressed proteins were identified using DeCyder Analysis Software v7.0. The tandem MS output was analyze with Mascot engine (Matrix Science, London, UK) using UNIPROT database.Results: Incubation with TGF-β1 or TGF-β3 but not TGF-β2 ablated Dex-induced GRE activity. Inhibition of the main non-canonical kinase pathways of TGF-β1 (ERK, JNK, p38MAPK, PI3K) did not inhibit TGF-β1-induced impairment of GRE activity so further proteomics were conducted in the presence of kinase inhibitors, prioritsising changes induced by TGF-b1 and TGF-b3, allowing identification of 3 proteins.Conclusions: Proteomic analysis identified Tropomyosin and Cofilin 1 either as potential candidate mediators of TGF-β-induced GC insensitivity or as being correlated to the mechanism. ER -