Differential regulation of dual NADPH oxidases/peroxidases, Duox1 and Duox2, by Th1 and Th2 cytokines in respiratory tract epithelium.
Partially reduced metabolites of molecular oxygen, superoxide (O2-) and hydrogen peroxide (H2O2), are detected in respiratory tract lining fluid, and it is assumed that these are key components of innate immunity. Whether these reactive oxygen species (ROS) are produced specifically by the respiratory epithelium in response to infection, or are a non-specific by-product of oxidant-producing inflammatory cells is not well characterized. Increasing evidence supports the hypothesis that the dual function NAD(P)H oxidases/peroxidases, Duox1 and Duox2, are important sources of regulated H2O2 production in respiratory tract epithelium. However, no studies to date have characterized the regulation of Duox gene expression. Accordingly, we examined Duox1 and Duox2 mRNA expression by real-time PCR in primary respiratory tract epithelial cultures after treatment with multiple cytokines. Herein, we determined that Duox1 expression was increased several-fold by treatment with the Th2 cytokines IL-4 and IL-13, whereas Duox2 expression was highly induced following treatment with the Th1 cytokine IFN-gamma. Duox2 expression was also elevated by polyinosine-polycytidylic acid (poly(I:C)) and rhinovirus infection. Diphenyleneiodonium (DPI)-inhibitable apical H2O2 production was similarly increased by the addition of Th1 or Th2 cytokines. These results demonstrate for the first time the regulation of Duox expression by immunomodulatory Th1 and Th2 cytokines, and suggest a mechanism by which ROS production can be regulated in the respiratory tract as part of the host defense response.
Harper
Richart W
RW
Department of Internal Medicine, Division of Pulmonary/Critical Care Medicine, School of Medicine, University of California, Davis, CA 95616, USA. rwharper@ucdavis.edu
Xu
Changhong
C
Eiserich
Jason P
JP
Chen
Yin
Y
Kao
Cheng-Yuan
CY
Thai
Philip
P
Setiadi
Henny
H
Wu
Reen
R
D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D000074623:Dual Oxidases; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005420:Flavoproteins / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism; D020545:Respiratory Mucosa / Q000166:cytology*; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D000998:Antiviral Agents; D016207:Cytokines; D005420:Flavoproteins; D016877:Oxidants; D006861:Hydrogen Peroxide; D000074623:Dual Oxidases; D019255:NADPH Oxidases; C431513:DUOX1 protein, human; C431515:DUOX2 protein, human