Mechanisms and function of DUOX in epithelia of the lung

Antioxid Redox Signal. 2009 Oct;11(10):2453-65. doi: 10.1089/ars.2009.2558.


The human lung produces considerable amounts of H(2)O(2). In the normal uninflamed epithelium of both the airways and the alveoli, mucosal release of H(2)O(2) is readily detected both in cell cultures in vitro and in the exhaled breath of humans. The dual oxidases DUOX1 and DUOX2 are the H(2)O(2)-producing isoforms of the NADPH oxidase family found in epithelial cells. The DUOXs are prominently expressed at the apical cell pole of ciliated cells in the airways and in type II cells of the alveoli. Recent studies focused on the functional consequences of H(2)O(2) release by DUOX into the lung lining fluid. In the airways, a major function of DUOX is to support lactoperoxidase (LPO) to generate bactericidal OSCN(-), and there are indications that the DUOX/LPO defense system is critically dependent on the function of the CFTR Cl(-) channel, which provides both SCN(-) (for LPO function) and HCO(3)(-) (for pH adjustment) to the airway surface liquid. Although DUOX is also functional in the alveolar epithelium, no comparable heme peroxidase is present in the alveolus, and thus DUOX-mediated H(2)O(2) release by alveolar cells may have other functions, such as cellular signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Calcium / metabolism
  • Cell Membrane / metabolism
  • Cystic Fibrosis / metabolism
  • Dual Oxidases
  • Epithelial Cells / cytology
  • Epithelial Cells / enzymology*
  • Humans
  • Hydrogen Peroxide / metabolism
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Lung* / anatomy & histology
  • Lung* / enzymology
  • NADPH Oxidases / genetics
  • NADPH Oxidases / metabolism*
  • Oxidants / metabolism
  • Respiratory Mucosa* / cytology
  • Respiratory Mucosa* / enzymology
  • Signal Transduction / physiology


  • Isoenzymes
  • Oxidants
  • Hydrogen Peroxide
  • Dual Oxidases
  • NADPH Oxidases
  • DUOX1 protein, human
  • Calcium