title: Long-acting β2-agonists promote glucocorticoid-mediated repression of NF-κB by enhancing expression of the feedback regulator TNFAIP3.
abstract: Glucocorticoids, or corticosteroids, are effective treatments for many chronic inflammatory diseases, and in mild/moderate asthma, long-acting β2-adrenoceptor agonists (LABAs) enhance the efficacy of inhaled corticosteroids (ICSs) more than increasing the ICS dose. In human bronchial epithelial, BEAS-2B, cells, expression of TNFα-induced protein-3 (TNFAIP3), or A20, a dual-ubiquitin ligase that provides feedback inhibition of NF-κB, was induced by budesonide, an ICS, and formoterol, a LABA, and was further enhanced by budesonide-formoterol combination. The proinflammatory cytokine TNF induced TNFAIP3 and TNF expression. Whereas subsequent budesonide treatment enhanced TNF-induced TNFAIP3 and reduced TNF expression, formoterol amplified these differential effects. In primary human airway smooth muscle cells, TNFAIP3 expression was induced by TNF. This was largely unaffected by budesonide but was acutely enhanced by budesonide-formoterol combination. In BEAS-2B cells, TNF recruited RELA, the main NF-κB transactivating subunit, to a 3' region of the TNF gene. RELA binding was reduced by budesonide, was further reduced by formoterol cotreatment, and was associated with reduced RNA polymerase II recruitment to the TNF gene. This is consistent with reduced TNF expression. TNFAIP3 knockdown enhanced TNF expression in the presence of TNF, TNF plus budesonide, and TNF plus budesonide-formoterol combination and confirms feedback inhibition. A luciferase reporter containing the TNF 3' RELA binding region recapitulated TNF inducibility and was inhibited by an IκB kinase inhibitor and TNFAIP3 overexpression. Repression of reporter activity by budesonide was increased by formoterol and involved TNFAIP3. Thus LABAs may improve the anti-inflammatory properties of ICSs by augmenting TNFAIP3 expression to negatively regulate NF-κB.
authors.affiliation: Department of Cell Biology and Anatomy, Airway Inflammation Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada.|Department of Zoology, Sohag University, Sohag, Egypt.
authors.forename: Mohammed O
authors.initials: MO
authors.lastname: Altonsy
authors.affiliation: Department of Cell Biology and Anatomy, Airway Inflammation Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Mostafa
authors.affiliation: Department of Medicine, National Jewish Health, Denver, Colorado; and.|Department of Medicine, University of Colorado, Denver, Colorado.
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Gerber
authors.affiliation: Department of Cell Biology and Anatomy, Airway Inflammation Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada; rnewton@ucalgary.ca.
authors.forename: Robert
authors.identifier: http://orcid.org/0000-0002-4919-8498
authors.initials: R
authors.lastname: Newton
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists / Q000494:pharmacology*; D001483:Base Sequence; D001665:Binding Sites; D019819:Budesonide / Q000494:pharmacology; D002460:Cell Line; D047369:Chromatin Immunoprecipitation; D025461:Feedback, Physiological / Q000187:drug effects*; D000068759:Formoterol Fumarate / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D020868:Gene Silencing / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D012319:RNA Polymerase II / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051996:Transcription Factor RelA / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000494:pharmacology
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D005938:Glucocorticoids; D016328:NF-kappa B; C498143:RELA protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D019819:Budesonide; D051550:I-kappa B Kinase; D012319:RNA Polymerase II; C076529:TNFAIP3 protein, human; D000072598:Tumor Necrosis Factor alpha-Induced Protein 3; D000068759:Formoterol Fumarate
keywords: NF-κB (RELA); TNFα-induced protein-3; chromatin immunoprecipitation (ChIP); glucocorticoid receptor; long-acting β2-agonist