Cigarette Smoke Regulates the Competitive Interactions between NRF2 and BACH1 for Heme Oxygenase-1 Induction
AbstractCigarette smoke has been shown to trigger aberrant signaling pathways and pathophysiological processes; however, the regulatory mechanisms underlying smoke-induced gene expression remain to be established. Herein, we observed that two smoke-responsive genes, HO-1 and CYP1A1, are robustly induced upon smoke by different mechanisms in human bronchial epithelia. CYP1A1 is mediated by aryl hydrocarbon receptor signaling, while induction of HO-1 is regulated by oxidative stress, and suppressed by N-acetylcysteine treatment. In light of a pivotal role of NRF2 and BACH1 in response to oxidative stress and regulation of HO-1, we examined if smoke-induced HO-1 expression is modulated through the NRF2/BACH1 axis. We demonstrated that smoke causes significant nuclear translocation of NRF2, but only a slight decrease in nuclear BACH1. Knockdown of NRF2 attenuated smoke-induced HO-1 expression while down-regulation of BACH1 had stimulatory effects on both basal and smoke-induced HO-1 with trivial influence on NRF2 nuclear translocation. Chromatin immunoprecipitation assays showed that smoke augments promoter-specific DNA binding of NRF2 but suppresses BACH1 binding to the HO-1 promoter ARE sites, two of which at −1.0 kb and −2.6 kb are newly identified. These results suggest that the regulation of NRF2 activator and BACH1 repressor binding to the ARE sites are critical for smoke-mediated HO-1 induction. View Full-Text
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Chang, W.-H.; Thai, P.; Xu, J.; Yang, D.C.; Wu, R.; Chen, C.-H. Cigarette Smoke Regulates the Competitive Interactions between NRF2 and BACH1 for Heme Oxygenase-1 Induction. Int. J. Mol. Sci. 2017, 18, 2386.
Chang W-H, Thai P, Xu J, Yang DC, Wu R, Chen C-H. Cigarette Smoke Regulates the Competitive Interactions between NRF2 and BACH1 for Heme Oxygenase-1 Induction. International Journal of Molecular Sciences. 2017; 18(11):2386.Chicago/Turabian Style
Chang, Wen-Hsin; Thai, Philip; Xu, Jihao; Yang, David C.; Wu, Reen; Chen, Ching-Hsien. 2017. "Cigarette Smoke Regulates the Competitive Interactions between NRF2 and BACH1 for Heme Oxygenase-1 Induction." Int. J. Mol. Sci. 18, no. 11: 2386.
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