Substrate-dependent metabolomic signatures of myeloperoxidase activity in airway epithelial cells: Implications for early cystic fibrosis lung disease.

Jun 26, 2023

Experts: Susan O Kim,Joseph P Shapiro,Kirsten A Cottrill,Genoah L Collins,Shivanthan Shanthikumar,Padma Rao,Sarath Ranganathan,Stephen M Stick,Michael L Orr,Anne M Fitzpatrick,Young-Mi Go,Dean P Jones,Rabindra M Tirouvanziam,Joshua D Chandler

Myeloperoxidase (MPO) is released by neutrophils in inflamed tissues. MPO oxidizes chloride, bromide, and thiocyanate to produce hypochlorous acid (HOCl), hypobromous acid (HOBr), and hypothiocyanous acid (HOSCN), respectively. These oxidants are toxic to pathogens, but may also react with host cells to elicit biological activity and potential toxicity. In cystic fibrosis (CF) and related diseases, increased neutrophil inflammation leads to increased airway MPO and airway epithelial cell (AEC) exposure to its oxidants. In this study, we investigated how equal dose-rate exposures of MPO-derived oxidants differentially impact the metabolome of human AECs (BEAS-2B cells). We utilized enzymatic oxidant production with rate-limiting glucose oxidase (GOX) coupled to MPO, and chloride, bromide (Br), or thiocyanate (SCN) as substrates. AECs exposed to GOX/MPO/SCN (favoring HOSCN) were viable after 24 h, while exposure to GOX/MPO (favoring HOCl) or GOX/MPO/Br (favoring HOBr) developed cytotoxicity after 6 h. Cell glutathione and peroxiredoxin-3 oxidation were insufficient to explain these differences. However, untargeted metabolomics revealed GOX/MPO and GOX/MPO/Br diverged significantly from GOX/MPO/SCN for dozens of metabolites. We noted methionine sulfoxide and dehydromethionine were significantly increased in GOX/MPO- or GOX/MPO/Br-treated cells, and analyzed them as potential biomarkers of lung damage in bronchoalveolar lavage fluid from 5-year-olds with CF (n = 27). Both metabolites were associated with increasing bronchiectasis, neutrophils, and MPO activity. This suggests MPO production of HOCl and/or HOBr may contribute to inflammatory lung damage in early CF. In summary, our in vitro model enabled unbiased identification of exposure-specific metabolite products which may serve as biomarkers of lung damage in vivo. Continued research with this exposure model may yield additional oxidant-specific biomarkers and reveal explicit mechanisms of oxidant byproduct formation and cellular redox signaling.
Copyright © 2023. Published by Elsevier Inc.

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ABOUT THE EXPERTS

Susan O Kim,Joseph P Shapiro,Kirsten A Cottrill,Genoah L Collins,Shivanthan Shanthikumar,Padma Rao,Sarath Ranganathan,Stephen M Stick,Michael L Orr,Anne M Fitzpatrick,Young-Mi Go,Dean P Jones,Rabindra M Tirouvanziam,Joshua D Chandler

Susan O Kim

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA.

Joseph P Shapiro

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA.

Kirsten A Cottrill

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA.

Genoah L Collins

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA.

Shivanthan Shanthikumar

Respiratory and Sleep Medicine, Royal Children’s Hospital, Parkville, VIC, Australia; Respiratory Diseases, Murdoch Children’s Research Institute, Parkville, VIC, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia.

Padma Rao

Medical Imaging, Royal Children’s Hospital, Parkville, VIC, Australia.

Sarath Ranganathan

Respiratory and Sleep Medicine, Royal Children’s Hospital, Parkville, VIC, Australia; Respiratory Diseases, Murdoch Children’s Research Institute, Parkville, VIC, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia.

Stephen M Stick

Telethon Kids Institute, Perth, Western Australia, Australia.

Michael L Orr

Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, GA, USA.

Anne M Fitzpatrick

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA; Children’s Healthcare of Atlanta, Atlanta, GA, USA.

Young-Mi Go

Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, GA, USA.

Dean P Jones

Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, GA, USA.

Rabindra M Tirouvanziam

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA; Children’s Healthcare of Atlanta, Atlanta, GA, USA.

Joshua D Chandler

Department of Pediatrics, Division of Pulmonary, Asthma, Cystic Fibrosis, and Sleep, Emory University, Atlanta, GA, USA; Department of Medicine, Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, Emory University, Atlanta, GA, USA; Children’s Healthcare of Atlanta, Atlanta, GA, USA. Electronic address: joshua.chandler@emory.edu.