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2262247 
Journal Article 
Abstract 
Cigarette smoke-generated hydrogen peroxide is mediated by the up-regulation of Nox-family member, Duox-1 and Nox-5 in bronchial epithelial cells 
Allen-Gipson, DS; White, AR; Keitt, FL; Jarrell, JC; Yanov, D; Wyatt, TA 
2010 
Yes 
American Journal of Respiratory and Critical Care Medicine
ISSN: 1073-449X
EISSN: 1535-4970 
181 
A3540 
English 
WOS:000208771002650 
is part of a larger document 3452678 Proceedings of the American Thoracic Society 2010 International Conference, May 14-19, 2010, New Orleans
Cigarette Smoke (CS) exposure as well as activation of inflammatory cells can produce high levels of reactive oxygen species (ROS). This activation has been linked to the initiation of the Nox enzyme family, NADPH oxidases. Nox enzymes generate ROS whose excessive production is associated with inflammatory tissue injury. We previously demonstrated that the CS-generated ROS, hydrogen peroxide impairs airway epithelial cell injury and recovery. Understanding that CS-generated hydrogen peroxide inhibits adenosine-mediated wound closure, we hypothesized that CS exposure upregulates expression of Duox-1 and or Nox-5, endogenous epithelial NADPH oxidases known to generate H2O2. To test this hypothesis, the human bronchial epithelial cell line NuLi-1 was used. Cells were exposed to 5% cigarette smoke extract (CSE) for various time points and lactate dehydrogenase assays were conducted to control for cytotoxicity. Real-time RT-PCR of RNA from NuLi-1 cells revealed CSE-stimulated transcriptional expression of Duox-1 and Nox-5. In addition, cells treated with Thapsigargin (1 μM), but not calcium ionophore (A23187; 1 μM) revealed increased transcriptional expression of both Duox-1 and Nox-5. Immunofluorescence localization revealed that CSE increased Duox-1 at 9 hours, but reduced expression with prolonged exposure. CSE stimulated the significant activation of protein kinase C alpha which was effectively blocked by diphenylene iodonium (1μM), an NADPH oxidase inhibitor. Collectively the data show that Duox-1 and Nox-5 are present in bronchial epithelial cells and their expression occurs via a calcium-dependent manner requiring the activation of Protein kinase C alpha. 
American Thoracic Society 2010 International Conference 
New Orleans, LA 
May 14-19, 2010