We have completed a genome-wide screen for chromosomal loci of susceptibility genes that control hyperoxia-induced pulmonary injury in an intercross (B6C3F2) cohort derived from susceptible C57BL/6J (B6) and resistant C3H/HeJ (C3) mice. Significant and suggestive quantitative trait loci (QTLs) were identified on chromosomes 2 and 3, respectively. A candidate gene within the chromosome 2 QTL is Nfe2l2 (nuclear factor, erythroid derived 2, like 2), which encodes a transcription factor NRF2 (NF-E2 related factor 2, Nrf2). NRF2 has been identified as an antioxidant response element (ARE)-mediated positive regulator of detoxifying enzymes genes for protecting cells against electrophile toxicity, oxidative stress, and carcinogenicity. To test the hypothesis that Nrf2 is a candidate gene for differential susceptibility in B6 and C3 mice, we sequenced Nrf2 in both strains. Analysis of the Nrf2 promoter in B6 and C3 mice revealed a potentially important variation between them. B6 mice possess a T to C substitution at -336, which is predicted to add a Sp1 transcription factor-binding site in B6 mice compared to C3. The polymorphism segregated with hyperoxia susceptibility in the B6C3F2 cohort, suggesting that the polymorphism is potentially an important determinant of suceptibility to hyperoxic lung injury in this model. We tested the hypothesis that NRF2 contributes to pulmonary protection against hyperoxic injury by exposing mice with site-directed mutation of Nrf2 (Nrf2-/-) and wild type (Nrf2+/+) mice to hyperoxia. Pulmonary hyperpermeability, macrophage inflammation, and epithelial injury were significantly greater in Nrf2-/- mice compared to Nrf2+/+ mice after exposure to hyperoxia. Consistent with a protective role for Nrf2 in hyperoxic lung injury, mRNA expression of multiple antioxidant and phase 2 genes, as well as antioxidant enzyme activities, were significantly lower in Nrf2-/- mice compared to Nrf2+/+ mice after hyperoxia. These studies have identified Nrf2 as an important susceptibility gene in the pathogenesis of oxidant-induced lung pathology in the mouse, and may have important implications for understanding similar processes in susceptible human populations.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Intramural Research (Z01)
Project #
1Z01ES100513-01
Application #
6677460
Study Section
(LPP)
Project Start
Project End
Budget Start
Budget End
Support Year
1
Fiscal Year
2002
Total Cost
Indirect Cost
Name
U.S. National Inst of Environ Hlth Scis
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Cho, Hye-Youn; Kleeberger, Steven R (2009) Nrf2 protects against airway disorders. Toxicol Appl Pharmacol :
Cho, Hye-Youn; Kleeberger, Steven R (2007) Genetic mechanisms of susceptibility to oxidative lung injury in mice. Free Radic Biol Med 42:433-45
Reddy, Narsa M; Kleeberger, Steven R; Cho, Hye-Youn et al. (2007) Deficiency in Nrf2-GSH signaling impairs type II cell growth and enhances sensitivity to oxidants. Am J Respir Cell Mol Biol 37:3-8
Marzec, Jacqui M; Christie, Jason D; Reddy, Sekhar P et al. (2007) Functional polymorphisms in the transcription factor NRF2 in humans increase the risk of acute lung injury. FASEB J 21:2237-46
Cho, Hye-Youn; Reddy, Sekhar P; Kleeberger, Steven R (2006) Nrf2 defends the lung from oxidative stress. Antioxid Redox Signal 8:76-87
Papaiahgari, Srinivas; Zhang, Qin; Kleeberger, Steven R et al. (2006) Hyperoxia stimulates an Nrf2-ARE transcriptional response via ROS-EGFR-PI3K-Akt/ERK MAP kinase signaling in pulmonary epithelial cells. Antioxid Redox Signal 8:43-52
Cho, Hye-Youn; Reddy, Sekhar P; Debiase, Andrea et al. (2005) Gene expression profiling of NRF2-mediated protection against oxidative injury. Free Radic Biol Med 38:325-43
Papaiahgari, Srinivas; Kleeberger, Steven R; Cho, Hye-Youn et al. (2004) NADPH oxidase and ERK signaling regulates hyperoxia-induced Nrf2-ARE transcriptional response in pulmonary epithelial cells. J Biol Chem 279:42302-12
Zhang, Qin; Kleeberger, Steven R; Reddy, Sekhar P (2004) DEP-induced fra-1 expression correlates with a distinct activation of AP-1-dependent gene transcription in the lung. Am J Physiol Lung Cell Mol Physiol 286:L427-36
Cho, Hye-Youn; Reddy, Sekhar P M; Yamamoto, Masayuki et al. (2004) The transcription factor NRF2 protects against pulmonary fibrosis. FASEB J 18:1258-60

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