title: Effect of the plant derivative Compound A on the production of corticosteroid-resistant chemokines in airway smooth muscle cells.
abstract: Preclinical models of human conditions including asthma showed the therapeutic potential of Compound A (CpdA), a dissociated glucocorticoid (GC) receptor (GRα) ligand. Whether CpdA inhibits GC resistance, a central feature of severe asthma, has not been addressed. We investigated whether CpdA modulates cytokine-induced GC resistance in human airway smooth muscle (ASM) cells. Healthy and asthmatic ASM cells were treated with TNF-α/IFN-γ for 24 hours in the presence or absence of CpdA. ELISA and quantitative PCR assays were used to assess the effect of CpdA on chemokine expression. Activation of GRα by CpdA was assessed by quantitative PCR, immunostaining, and receptor antagonism using RU486. An effect of CpdA on the transcription factor interferon regulatory factor 1 (IRF-1) was investigated using immunoblot, immunostaining, and small interfering RNA (siRNA) knockdown. CpdA inhibited production of fluticasone-resistant chemokines CCL5, CX3CL1, and CXCL10 at protein and mRNA levels in both asthmatic and healthy cells. CpdA failed to induce expression of GC-induced Leucine Zipper while transiently inducing mitogen-activated protein kinase phosphatase 1 (MKP-1) at both mRNA and protein levels. CpdA inhibitory action was not associated with GRα nuclear translocation, nor was it prevented by RU486 antagonism. Activation of IRF-1 by TNF-α/IFN-γ was inhibited by CpdA. IRF-1 siRNA knockdown reduced cytokine-induced CCL5 and CX3CL1 production. siRNA MKP-1 prevented the inhibitory effect of CpdA on cytokine-induced CXCL10 production. For the first time, we show that CpdA inhibits the production of GC-resistant chemokines via GRα-independent mechanisms involving the inhibition of IRF-1 and up-regulation of MKP-1. Thus, targeting CpdA-sensitive pathways in ASM cells represents an alternative therapeutic approach to treat GC resistance in asthma.
authors.affiliation: 1 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Adelina
authors.initials: A
authors.lastname: Gavrila
authors.affiliation: 1 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Latifa
authors.initials: L
authors.lastname: Chachi
authors.affiliation: 2 Department of Pharmaceutical Sciences, Thomas Jefferson University, Jefferson School of Pharmacy, Philadelphia, Pennsylvania.
authors.forename: Omar
authors.initials: O
authors.lastname: Tliba
authors.affiliation: 1 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Christopher
authors.initials: C
authors.lastname: Brightling
authors.affiliation: 1 Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Yassine
authors.initials: Y
authors.lastname: Amrani
mesh_terms: D000085:Acetates / Q000494:pharmacology*; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000494:pharmacology; D001249:Asthma / Q000188:drug therapy / Q000235:genetics / Q000276:immunology / Q000473:pathology; D016022:Case-Control Studies; D018946:Chemokine CCL5 / Q000235:genetics / Q000276:immunology; D054428:Chemokine CX3CL1 / Q000235:genetics / Q000276:immunology; D054357:Chemokine CXCL10 / Q000235:genetics / Q000276:immunology; D004351:Drug Resistance / Q000187:drug effects*; D054638:Dual Specificity Phosphatase 1 / Q000235:genetics / Q000276:immunology; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D005260:Female; D000068298:Fluticasone / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects* / Q000276:immunology; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D015735:Mifepristone / Q000494:pharmacology; D061251:Primary Cell Culture; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000276:immunology; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014439:Tyramine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C104564:2-(4-acetoxyphenyl)-2-chloro-N-methylethylamine; D000085:Acetates; D018927:Anti-Asthmatic Agents; C483024:CCL5 protein, human; C515538:CX3CL1 protein, human; C114753:CXCL10 protein, human; D018946:Chemokine CCL5; D054428:Chemokine CX3CL1; D054357:Chemokine CXCL10; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D034741:RNA, Small Interfering; D011965:Receptors, Glucocorticoid; D014409:Tumor Necrosis Factor-alpha; C411470:glucocorticoid receptor alpha; D015735:Mifepristone; D007371:Interferon-gamma; D000068298:Fluticasone; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; D014439:Tyramine
keywords: asthma therapies; chemokines; refractory patients; severe asthma; transcription factors