Pseudomonas aeruginosa Pyocyanin Activates NRF2-ARE-Mediated Transcriptional Response via the ROS-EGFR-PI3K-AKT/MEK-ERK MAP Kinase Signaling in Pulmonary Epithelial Cells

Ying Xu, Chaohui Duan, Zhizhou Kuang, Yonghua Hao, Jayme L. Jeffries, Gee W. Lau

Research output: Contribution to journalArticle

Abstract

The redox-active pyocyanin (PCN) secreted by the respiratory pathogen Pseudomonas aeruginosa generates reactive oxygen species (ROS) and causes oxidative stress to pulmonary epithelial cells. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) confers protection against ROS-mediated cell death by inducing the expression of detoxifying enzymes and proteins via its binding to the cis-acting antioxidant response element (ARE). However, a clear relationship between NRF2 and PCN-mediated oxidative stress has not been established experimentally. In this study, we investigated the induction of NRF2-ARE response by PCN in the pulmonary epithelial cells. We analyzed the effect of PCN on NRF2 expression and nuclear translocation in cultured human airway epithelial cells, and in a mouse model of chronic PCN exposure. NRF2-dependent transcription of antioxidative enzymes was also assessed. Furthermore, we used inhibitors to examine the involvement of EGFR and its downstream signaling components that mediate NRF2-ARE-activation in response to PCN. PCN enhances the nuclear NRF2 accumulation and activates the transcription of ARE-mediated antioxidant genes. Furthermore, PCN activates NRF2 by inducing the EGFR-phosphoinositide-3-kinase (PI3K) signaling pathway and its main downstream effectors, AKT and MEK1/2-ERK1/2 MAP kinases. Inhibition of the EGFR-PI3K signaling markedly attenuates PCN-stimulated NRF2 accumulation in the nucleus. We demonstrate for the first time that PCN-mediated oxidative stress activates the EGFR-PI3K-AKT/MEK1/2-ERK1/2 MAP kinase signaling pathway, leading to nuclear NRF2 translocation and ARE responsiveness in pulmonary epithelial cells.

Original languageEnglish (US)
Article numbere72528
JournalPloS one
Volume8
Issue number8
DOIs
StatePublished - Aug 27 2013

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

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