Pannexin 1 contributes to ATP release in airway epithelia

George A. Ransford, Nevis L. Fregien, Feng Qiu, Gerhard Dahl, Gregory E Conner, Matthias A Salathe

Research output: Contribution to journalArticle

144 Citations (Scopus)

Abstract

ATP is a paracrine regulator of critical airway epithelial cell functions, but the mechanism of its release is poorly understood. Pannexin (Panx) proteins, related to invertebrate innexins, form channels (called pannexons) that are able to release ATP from several cell types. Thus, ATP release via pannexons was examined in airway epithelial cells. Quantitative RT-PCR showed Panx1 expression in normal human airway epithelial cells during redifferentiation at the air-liquid interface (ALI), at a level comparable to that of alveolar macrophages; Panx3 was not expressed. Immunohistochemistry showed Panx1 expression at the apical pole of airway epithelia. ALI cultures exposed to hypotonic stress released ATP to an estimated maximum of 255 (±64) nM within 1 minute after challenge (n = 6 cultures from three different lungs) or to approximately 1.5 (±0.4) mM, recalculated to a normal airway surface liquid volume. Using date- and culture-matched cells (each n ≥ 16 from 4 different lungs), the pannexon inhibitors carbenoxolone (10 μM) and probenecid (1 mM), but not the connexon inhibitor flufenamic acid (100 μM), inhibited ATP release by approximately 60%. The drugs affected Panx1 currents in Xenopus oocytes expressing exogenous Panx1 correspondingly. In addition, suppression of Panx1 expression using lentivirus-mediated production of shRNA in differentiated airway epithelial cells inhibited ATP release upon hypotonic stress by approximately 60% as well. These data not only show that Panx1 is expressed apically in differentiated airway epithelial cells but also that it contributes to ATP release in these cells.

Original languageEnglish
Pages (from-to)525-534
Number of pages10
JournalAmerican Journal of Respiratory Cell and Molecular Biology
Volume41
Issue number5
DOIs
StatePublished - Nov 26 2009

Fingerprint

Epithelium
Adenosine Triphosphate
Epithelial Cells
Osmotic Pressure
Liquids
Flufenamic Acid
Air
Carbenoxolone
Probenecid
Lung
Lentivirus
Alveolar Macrophages
Invertebrates
Xenopus
Small Interfering RNA
Oocytes
Poles
Cell Culture Techniques
Immunohistochemistry
Polymerase Chain Reaction

Keywords

  • Airway epithelia
  • ATP release
  • Pannexin

ASJC Scopus subject areas

  • Cell Biology
  • Pulmonary and Respiratory Medicine
  • Molecular Biology
  • Clinical Biochemistry

Cite this

Pannexin 1 contributes to ATP release in airway epithelia. / Ransford, George A.; Fregien, Nevis L.; Qiu, Feng; Dahl, Gerhard; Conner, Gregory E; Salathe, Matthias A.

In: American Journal of Respiratory Cell and Molecular Biology, Vol. 41, No. 5, 26.11.2009, p. 525-534.

Research output: Contribution to journalArticle

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