Peer Reviewed

1

Document Type

Article

Publication Date

15-7-2014

Keywords

Adolescent, Biomarkers, Blotting, Western, Bronchoalveolar Lavage Fluid, Cathepsins, Cell Line, Child, Child, Preschool, Cystic Fibrosis, Down-Regulation, Enzyme-Linked Immunosorbent Assay, Humans, Infant, Interferon Regulatory Factor-1, MicroRNAs, Peptide Hydrolases, Pseudomonas Infections, Pseudomonas aeruginosa, Respiratory Mucosa, Reverse Transcriptase Polymerase Chain Reaction

Comments

Originally Published in: Weldon S, McNallyP, McAuley DF, Oglesby IK, Wohlford-Lenane CL, Bartlett JA, Scott CJ, McElvaney NG, Greene CM, McCray PB Jr., Taggart CC. miR-31 dysregulation in cystic fibrosis airways contributes to increased pulmonary cathepsin S production. American Journal of Respiratory and Critical Care Medicine Volume. 2014;190:165-174. DOI: 10.1164/rccm.201311-1986OC. Copyright © 2015 by the American Thoracic Society. The final publication is available at http://www.atsjournals.org/

Abstract

RATIONALE: Cathepsin S (CTSS) activity is increased in bronchoalveolar lavage (BAL) fluid from patients with cystic fibrosis (CF). This activity contributes to lung inflammation via degradation of antimicrobial proteins, such as lactoferrin and members of the β-defensin family.

OBJECTIVES: In this study, we investigated the hypothesis that airway epithelial cells are a source of CTSS, and mechanisms underlying CTSS expression in the CF lung.

METHODS: Protease activity was determined using fluorogenic activity assays. Protein and mRNA expression were analyzed by ELISA, Western blotting, and reverse-transcriptase polymerase chain reaction.

MEASUREMENTS AND MAIN RESULTS: In contrast to neutrophil elastase, CTSS activity was detectable in 100% of CF BAL fluid samples from patients without Pseudomonas aeruginosa infection. In this study, we identified epithelial cells as a source of pulmonary CTSS activity with the demonstration that CF airway epithelial cells express and secrete significantly more CTSS than non-CF control cells in the absence of proinflammatory stimulation. Furthermore, levels of the transcription factor IRF-1 correlated with increased levels of its target gene CTSS. We discovered that miR-31, which is decreased in the CF airways, regulates IRF-1 in CF epithelial cells. Treating CF bronchial epithelial cells with a miR-31 mimic decreased IRF-1 protein levels with concomitant knockdown of CTSS expression and secretion.

CONCLUSIONS: The miR-31/IRF-1/CTSS pathway may play a functional role in the pathogenesis of CF lung disease and may open up new avenues for exploration in the search for an effective therapeutic target.

Disciplines

Medicine and Health Sciences

Citation

Weldon S, McNally P, McAuley DF, Oglesby IK, Wohlford-Lenane CL, Bartlett JA, Scott CJ, McElvaney NG, Greene CM, McCray PB Jr, Taggart CC. miR-31 dysregulation in cystic fibrosis airways contributes to increased pulmonary cathepsin S production. American Journal of Respiratory and Critical Care Medicine Volume. 2014;190:165-174

PubMed ID

24940638

DOI Link

10.1164/rccm.201311-1986OC

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

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