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Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A strong role for reactive oxygen species (ROS) has been proposed in the pathogenesis of a number of lung diseases. Hyperoxia (> 95% oxygen) generates ROS and extensive lung damage, and has been used as a model of oxidant injury. However, the precise mechanisms of hyperoxia-induced toxicity have not been completely clarified. This study was designed to identify hyperoxia susceptibility genes in C57BL/6J (susceptible) and C3H/HeJ (resistant) mice. The quantitative phenotypes used for this analysis were pulmonary inflammatory cell influx, epithelial cell sloughing, and hyperpermeability. Genome-wide linkage analyses of intercross (F2) and recombinant inbred cohorts identified significant and suggestive quantitative trait loci on chromosomes 2 (hyperoxia susceptibility locus 1 [Hsl1]) and 3 (Hsl2), respectively. Comparative mapping of Hsl1 identified a strong candidate gene, Nfe2l2 (nuclear factor, erythroid derived 2, like 2 or Nrf2) that encodes a transcription factor NRF2 which regulates antioxidant and phase 2 gene expression. Strain-specific variation in lung Nrf2 messenger RNA expression and a T --> C substitution in the B6 Nrf2 promoter that cosegregated with susceptibility phenotypes in F2 animals supported Nrf2 as a candidate gene. Results from this study have important implications for understanding the mechanisms through which oxidants mediate the pathogenesis of lung disease.
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PMID:Linkage analysis of susceptibility to hyperoxia. Nrf2 is a candidate gene. 1175 Dec 2

Genetic background is a known predisposing risk factor for many acute and chronic pulmonary disorders and responses to environmental oxidants. Variation in lung injury responses to oxidative stimuli such as ozone, particles, hyperoxia, and chemotherapeutic agents between genetically standardized inbred mouse strains has been demonstrated. In this review, we discuss quantitative trait loci (QTLs) which contain candidate genes that confer differential susceptibility to oxidative stimuli between strains in mouse models of airway toxicity and disease. We addressed multiple inflammatory, immunity, and antioxidant genes identified as candidate genetic determinants following these strategies, which include tumor necrosis factor (Tnf), toll-like receptor 4 (Tlr4), and the transcription factor NF-E2, related factor 2 (Nrf2). Mice with targeted deletion of these and related genes have provided initial proof of concept for their importance in the respective models. Interestingly, a few regions of the genome appear to have important roles in determining susceptibility to a number of stimuli which may suggest common genetic mechanisms in mice. Though more complete examination of functional association is required, results have potential implications for the role of these candidate genes in the pathogenesis of human pulmonary diseases including asthma, acute respiratory distress syndrome (ARDS), idiopathic pulmonary fibrosis (IPF), and emphysema.
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PMID:Genetic mechanisms of susceptibility to oxidative lung injury in mice. 1727 75

Hyperoxic lung injury is a major concern in critically ill patients who receive high concentrations of oxygen to treat lung diseases. Successful abrogation of hyperoxic lung injury would have a huge impact on respiratory and critical care medicine. Hydrogen can be administered as a therapeutic medical gas. We recently demonstrated that inhaled hydrogen reduced transplant-induced lung injury and induced heme oxygenase (HO)-1. To determine whether hydrogen could reduce hyperoxic lung injury and investigate the underlying mechanisms, we randomly assigned rats to four experimental groups and administered the following gas mixtures for 60 h: 98% oxygen (hyperoxia), 2% nitrogen; 98% oxygen (hyperoxia), 2% hydrogen; 98% balanced air (normoxia), 2% nitrogen; and 98% balanced air (normoxia), 2% hydrogen. We examined lung function by blood gas analysis, extent of lung injury, and expression of HO-1. We also investigated the role of NF-E2-related factor (Nrf) 2, which regulates HO-1 expression, by examining the expression of Nrf2-dependent genes and the ability of hydrogen to reduce hyperoxic lung injury in Nrf2-deficient mice. Hydrogen treatment during exposure to hyperoxia significantly improved blood oxygenation, reduced inflammatory events, and induced HO-1 expression. Hydrogen did not mitigate hyperoxic lung injury or induce HO-1 in Nrf2-deficient mice. These findings indicate that hydrogen gas can ameliorate hyperoxic lung injury through induction of Nrf2-dependent genes, such as HO-1. The findings suggest a potentially novel and applicable solution to hyperoxic lung injury and provide new insight into the molecular mechanisms and actions of hydrogen.
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PMID:Hydrogen gas reduces hyperoxic lung injury via the Nrf2 pathway in vivo. 2347 67