Variable overoxidation of peroxiredoxins in human lung cells in severe oxidative stress (original) (raw)
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Data demonstrating the role of peroxiredoxin 2 as important anti-oxidant system in lung homeostasis
Data in brief, 2017
The data presented in this article are related to the research paper entitled "peroxiredoxin-2 plays a pivotal role as multimodal cytoprotector in the early phase of pulmonary hypertension" (Federti et al., 2017) [1]. Data show that the absence of peroxiredoxin-2 (Prx2) is associated with increased lung oxidation and pulmonary vascular endothelial dysfunction. Prx2-/- mice displayed activation of the redox-sensitive transcriptional factors, NF-kB and Nrf2, and increased expression of cytoprotective system such as heme-oxygenase-1 (HO-1). We also noted increased expression of both markers of vascular activation and extracellular matrix remodeling. The administration of the recombinant fusion protein PEP Prx2 reduced the activation of NF-kB and Nrf2 and was paralleled by a decrease in HO-1 and in vascular endothelial abnormal activation. Prolonged hypoxia was used to trigger pulmonary artery hypertension (PAH). Prx2-/- precociously developed PAH compared to wildtype animals.
Differential parameters between cytosolic 2-Cys peroxiredoxins, PRDX1 and PRDX2
Protein Science, 2018
Peroxiredoxins are thiol-dependent peroxidases that function in peroxide detoxification and H 2 O 2 induced signaling. Among the six isoforms expressed in humans, PRDX1 and PRDX2 share 97% sequence similarity, 77% sequence identity including the active site, subcellular localization (cytosolic) but they hold different biological functions albeit associated with their peroxidase activity. Using recombinant human PRDX1 and PRDX2, the kinetics of oxidation and hyperoxidation with H 2 O 2 and peroxynitrite were followed by intrinsic fluorescence. At pH 7.4, the peroxidatic cysteine of both isoforms reacts nearly tenfold faster with H 2 O 2 than with peroxynitrite, and both reactions are orders of magnitude faster than with most protein thiols. For both isoforms, the sulfenic acids formed are in turn oxidized by H 2 O 2 with rate constants of ca 2 × 10 3 M −1 s −1 and by peroxynitrous acid significantly faster. As previously observed, a crucial difference between PRDX1 and PRDX2 is on the resolution step of the catalytic cycle, the rate of disulfide formation (11 s −1 for PRDX1, 0.2 s −1 for PRDX2, independent of the oxidant) which correlates with their different sensitivity to hyperoxidation. This kinetic pause opens different pathways on redox signaling for these isoforms. The longer lifetime of PRDX2 sulfenic acid allows it to react with other protein thiols to translate the signal via an intermediate mixed disulfide (involving its peroxidatic cysteine), whereas PRDX1 continues the cycle forming disulfide involving its resolving cysteine to function as a redox relay. In addition, the presence of C83 on PRDX1 imparts a difference on peroxidase activity upon peroxynitrite exposure that needs further study.
Free Radical Biology and Medicine, 2010
Peroxiredoxin 2 (Prx2), the third most abundant cytoplasmic protein in red blood cells (RBCs), is involved in the defense against oxidative stress. Although much is known about Prx2 in healthy RBCs, its role in pathological RBCs remains largely unexplored. Here, we show that the expression and net content of Prx2 are markedly increased in RBCs from two mouse models of βthalassemia (β-thal; Hbb th/th and Hbb th3/+ strains). We also demonstrate that the increased expression of Prx2 correlates with the severity of the disease and that the amount of Prx2 bound to the membrane is markedly reduced in β-thal mouse RBCs. To explore the impact of oxidative stress on Prx2 membrane association, we examined Prx2 dimerization and membrane translocation in murine RBCs exposed to various oxidants (phenylhydrazine, PHZ; diamide; H 2 O 2 ). PHZ-treated RBCs, which mimic the membrane damage in β-thal RBCs, exhibited a kinetic correlation among Prx2 membrane displacement, intracellular methemoglobin levels, and hemichrome membrane association, suggesting the possible masking of Prx2 docking sites by membrane-bound hemichromes, providing a possible mechanism for the accumulation of oxidized/dimerized Prx2 in the cytoplasm and the increased membrane damage in β-thal RBCs. Thus, reduced access of Prx2 to the membrane in β-thal RBCs represents a new factor that could contribute to the oxidative damage characterizing the pathology.
Induction of 1-cys peroxiredoxin expression by oxidative stress in lung epithelial cells
American journal of physiology. Lung cellular and molecular physiology, 2003
1-Cys peroxiredoxin (1-cysPrx), a member of the peroxiredoxin family that contains a single conserved cysteine residue, reduces a broad spectrum of hydroperoxides. We studied changes in 1-cysPrx expression in rat lungs and lung cell lines in response to oxidative stress due to hyperoxia, H2O2, or paraquat. After 60 h of hyperoxia (>95% O2), mRNA and protein levels of 1-cysPrx and peroxidase activity were significantly elevated in rat lungs by approximately 1.5- to 2-fold compared with the control (P < 0.05). A similar induction of 1-cysPrx was observed in mouse lungs following exposure to O2 for 63 or 72 h; enzyme induction in mouse lungs was similar for wild-type and glutathione peroxidase 1 gene-targeted mice. H2O2 and paraquat treatment induced 1-cysPrx gene expression in L2 cells. Enzyme induction was attenuated by pretreatment with Trolox or N-acetylcysteine. Actinomycin D treatment showed that stability of 1-cysPrx mRNA was not altered in the presence of H2O2 or paraquat...
Time course of inflammation, oxidative stress and tissue damage induced by hyperoxia in mouse lungs
International Journal of Experimental Pathology, 2012
Acute lung injury (ALI) affects a large number of patients worldwide, with reported mortality rates of 35-40% (Rubenfeld & Herridge 2007). Many patients with ALI require oxygen supplementation to maintain adequate tissue oxygenation, leading to hyperoxia (Fisher & Beers 2008). However, exposure to hyperoxia can have pathological effects, such as lung inflammation and oedema accompanied by epithelial and endothelial cell death, suggesting that oxygen supplementation, although necessary, may potentially perpetuate or exacerbate ALI (Bhandari et al. 2006; Bhandari 2008). Paradoxically, hyperoxia may cause ALI and damage to components of the extracellular matrix (Murray et al. 2008). Moreover, hyperoxia has been linked to the production of reactive oxygen species (ROS) and subsequent oxida-tive stress (Huang et al. 2009). Reactive oxygen species are important mediators in ALI, attacking biological molecules and causing lipid peroxidation, protein oxidation and DNA breakage (Papaiahgari et al. 2006). Under physiological conditions, living organisms maintain a balance between the formation and removal of ROS (Owuor & Kong 2002). The antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase and non-enzymatic antioxidants, such as a-tocopherol, vitamin-C, carotenoids and the glutathione system, all prevent the formation of toxic levels of ROS. Oxidative stress occurs when the generation of ROS in a system exceeds the system's capacity to neutralize and eliminate the ROS (Sies 1997
Lung injury and mortality with hyperoxia are increased in Peroxiredoxin 6 gene-targeted mice
Free Radical Biology and Medicine, 2004
Overexpression of peroxiredoxin 6 (Prdx6) has been shown to protect lungs of mice against hyperoxiamediated injury. In this study, we evaluated whether genetic inactivation of Prdx6 in mice increases sensitivity to oxygen toxicity. We evaluated mouse survival, lung histopathology, total protein and nucleated cells in bronchoalveolar lavage fluid (BALF), and oxidation of lung protein and lipids by measurement of protein carbonyls and thiobarbituric reactive substances (TBARS), respectively. The duration of survival for Prdx6 À/À mice was significantly shorter than that observed in wild-type mice on exposure to 85 or 100% O 2 ; survival of Prdx6 +/À mice was intermediate. After 72-h exposure to 100% O 2 , lungs of Prdx6À/À mice showed more severe injury than wild-type with increased wet/dry weight, epithelial cell necrosis and alveolar edema on microscopic examination, increased protein and nucleated cells in BALF, and higher content of TBARS and protein carbonyls in lung homogenate. These findings show that Prdx6 À/À mice have increased sensitivity to hyperoxia and provide in vivo evidence that Prdx6 is an important lung antioxidant enzyme. D
Transgenic Mice Overexpressing Peroxiredoxin 6 Show Increased Resistance to Lung Injury in Hyperoxia
American Journal of Respiratory Cell and Molecular Biology, 2006
Peroxiredoxin 6 (Prdx6) is a novel peroxidase enzyme that is expressed at a high level in the lung. We tested the hypothesis that transgenic (Tg) mice overexpressing Prdx6 would exhibit increased resistance to hyperoxia-induced lung injury. Wild-type and Tg mice were exposed to 100% O 2 and evaluated for survival, lung histopathology, total protein, and nucleated cells in bronchoalveolar lavage fluid (BALF), and oxidation of lung protein and lipids. Prdx6 protein expression and enzyme activity were ف 3-fold higher in Tg lungs compared with wild-type. Tg mice survived longer during exposure to 100% O 2 (LT 50 104 Ϯ 2.8 h in Tg versus 88.9 Ϯ 1.1 h for wildtype). Lung wet/dry weight ratio and total protein and nucleated cell count in lung lavage fluid were significantly greater in wildtype mice at 72 and 96 h of hyperoxia compared with Tg mice. At 96 h of hyperoxia, Tg mice had less epithelial cell necrosis, perivascular edema, and inflammatory cell recruitment by light microscopy, and lower TBARS and protein carbonyls in lung homogenate (P Ͻ 0.05). These results show that Tg mice have increased defense against lung injury in hyperoxia, providing evidence that Prdx6 functions as a lung antioxidant enzyme.
Role of peroxiredoxin-2 in protecting RBCs from hydrogen peroxide-induced oxidative stress
Free Radical Research, 2013
The role of peroxiredoxin-2 (PRDX2) in preventing hydrogen peroxide-induced oxidative stress in the red blood cell was investigated by comparing blood from PRDX2 knockout mice with superoxide dismutase-1 (SOD1) knockout and control mice. Loss of PRDX2 increased basal levels of methemoglobin and heme degradation (a marker for oxidative stress), and reduced red blood cell deformability. In vitro incubation under normoxic conditions, both with and without inhibition of catalase, resulted in a lag phase during which negligible heme degradation occurred followed by a more rapid rate of heme degradation in the absence of PRDX2. The appreciable basal increase in heme degradation for PRDX2 knockout mice, together with the lag during in vitro incubation, implies that PRDX2 neutralizes hydrogen peroxide generated in vivo under the transient hypoxic conditions experienced as the cells pass through the microcirculation.
Prostaglandins, Leukotrienes and Essential Fatty Acids, 2007
The 12S-lipoxygenase (12S-LOX) pathway of arachidonic acid (AA) metabolism is bifurcated at 12(S)-hydroperoxy-5Z,8Z,10E (12S-HpETE) in the reduction route to form 12S-hydroxy-eicosatetraenoic acid (12S-HETE) and in 8(S/R)-hydroxy-11(S),12Strans-epoxyeicosa-5Z,9E,14Z-trienoic acid (HXA 3) synthase pathway, previously known as isomerization route, to form hepoxilins. Earlier we showed that the HXA 3 formation is restricted to cellular systems devoid of hydroperoxide reducing enzymes, e.g. GPxs, thus causing a persistent oxidative stress situation. Here, we show that HXA 3 at as low as 100 nM concentration upregulates phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA and protein expressions, whereas other metabolites of AA metabolism 12S-HpETE and 12S-HETE failed to stimulate the PHGPx. Moreover, the decrease in 12S-HpETE below a threshold value of the hydroperoxide tone causes both suppression of the overall 12S-LOX activity and a shift from HXA 3 formation towards 12S-HETE formation. We therefore propose that under persistent oxidative stress the formation of HXA 3 and the HXA 3-induced upregulation of PHGPx constitute a compensatory defense response to protect the vitality and functionality of the cell.
Regulation of Reactive Oxygen Species Homeostasis by Peroxiredoxins and c-Myc
Journal of Biological Chemistry, 2009
Peroxiredoxins (Prxs) are highly conserved proteins found in most organisms, where they function primarily to scavenge reactive oxygen species (ROS). Loss of the most ubiquitous member of the family, Prx1, is associated with the accumulation of oxidatively damaged DNA and a tumor-prone phenotype. Prx1 interacts with the transcriptional regulatory domain of the c-Myc oncoprotein and suppresses its transforming activity. The DNA damage in tissues of prx1 ؊/؊ mice is associated in some cases with only modest increases in total ROS levels. However, these cells show dramatic increases in nuclear ROS and reduced levels of cytoplasmic ROS, which explains their mutational susceptibility. In the current work, we have investigated whether changes in other ROS scavengers might account for the observed ROS redistribution pattern in prx1 ؊/؊ cells. We show ϳ5-fold increases in Prx5 levels in prx1 ؊/؊ embryo fibroblasts relative to prx1 ؉/؉ cells. Moreover, Prx5 levels normalize when Prx1 expression is restored. Prx5 levels also appear to be highly dependent on c-Myc, and chromatin immunoprecipitation experiments showed differential occupancy of c-Myc and Prx1 complexes at E-box elements in the prx5 gene proximal promoter. This study represents a heretofore unreported mechanism for the c-Myc-dependent regulation of one Prx family member by another and identifies a novel means by which cells reestablish ROS homeostasis when one of these family members is compromised.