title: Diacetyl induces amphiregulin shedding in pulmonary epithelial cells and in experimental bronchiolitis obliterans.
abstract: Diacetyl (DA), a component of artificial butter flavoring, has been linked to the development of bronchiolitis obliterans (BO), a disease of airway epithelial injury and airway fibrosis. The epidermal growth factor receptor ligand, amphiregulin (AREG), has been implicated in other types of epithelial injury and lung fibrosis. We investigated the effects of DA directly on the pulmonary epithelium, and we hypothesized that DA exposure would result in epithelial cell shedding of AREG. Consistent with this hypothesis, we demonstrate that DA increases AREG by the pulmonary epithelial cell line NCI-H292 and by multiple independent primary human airway epithelial donors grown under physiologically relevant conditions at the air-liquid interface. Furthermore, we demonstrate that AREG shedding occurs through a TNF-α-converting enzyme (TACE)-dependent mechanism via inhibition of TACE activity in epithelial cells using the small molecule inhibitor, TNF-α protease inhibitor-1, as well as TACE-specific small inhibitor RNA. Finally, we demonstrate supportive in vivo results showing increased AREG transcript and protein levels in the lungs of rodents with DA-induced BO. In summary, our novel in vitro and in vivo observations suggest that further study of AREG is warranted in the pathogenesis of DA-induced BO.
authors.affiliation: Divisions of 1 Pulmonary, Allergy, and Critical Care Medicine, and.
authors.forename: Francine L
authors.initials: FL
authors.lastname: Kelly
authors.forename: Jesse
authors.initials: J
authors.lastname: Sun
authors.forename: Bernard M
authors.initials: BM
authors.lastname: Fischer
authors.forename: Judith A
authors.initials: JA
authors.lastname: Voynow
authors.forename: Apparao B
authors.initials: AB
authors.lastname: Kummarapurugu
authors.forename: Helen L
authors.initials: HL
authors.lastname: Zhang
authors.forename: Julia L
authors.initials: JL
authors.lastname: Nugent
authors.forename: Robert F
authors.initials: RF
authors.lastname: Beasley
authors.forename: Tereza
authors.initials: T
authors.lastname: Martinu
authors.forename: William M
authors.initials: WM
authors.lastname: Gwinn
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Morgan
authors.forename: Scott M
authors.initials: SM
authors.lastname: Palmer
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000072198:ADAM17 Protein; D066258:Amphiregulin; D001989:Bronchiolitis Obliterans / Q000139:chemically induced* / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D003931:Diacetyl / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D066255:EGF Family of Proteins / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005421:Flavoring Agents / Q000633:toxicity*; D006801:Humans; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D034622:RNA Interference; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
chemical_list: C587848:AREG protein, human; D066258:Amphiregulin; C587850:Areg protein, rat; D066255:EGF Family of Proteins; D004791:Enzyme Inhibitors; D005421:Flavoring Agents; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606464:Adam17 protein, rat; D003931:Diacetyl
keywords: TNF-α–converting enzyme; amphiregulin; bronchiolitis obliterans; diacetyl; epidermal growth factor receptor