Living with stress: Regulation of antioxidant defense genes in the subterranean, hypoxia-tolerant mole rat, Spalax

Schülke, Stefan; Dreidax, Daniel; Malik, Assaf; Burmester, Thorsten; Nevo, Eviatar; Band, Mark; Avivi, Aaron; Hankeln, Thomas

doi:10.1016/j.gene.2012.03.019

Cited by 66 publications

(51 citation statements)

References 82 publications

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“…The second one includes enzymes maintaining redox homeostasis within the cell [glutathione reductase (GSR), thioredoxins (TXNs) and its reductases (TXRD)], and the third one includes antioxidants related to iron metabolism [heme oxygenase (HMOX) and aconitase (ACO1)]. Apparently, different components of the cardiac antioxidant system may participate in the antioxidant response to diverse hypoxic conditions (10,11,30,42).Studies dealing with antioxidant responses of the heart to chronic hypoxic stress provide only fragmented information, and heterogeneous data obtained in diverse models and protocols of hypoxia under different experimental conditions do not offer a clear view on this issue. In the present study we aimed to assess the level of oxidative stress and mRNA transcripts of 20 antioxidant genes and related regulatory proteins in rat myocardium after adaptation to three regimens of chronic hypoxia that differ in their ability to reduce I/R injury.…”

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Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems

Kasparova

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Dabrowská

et al. 2015

Physiological Genomics

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Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems. Physiol Genomics 47: 612-620, 2015. First published October 13, 2015; doi:10.1152/physiolgenomics.00058.2015.-It has been documented that adaptation to hypoxia increases myocardial tolerance to ischemia-reperfusion (I/R) injury depending on the regimen of adaptation. Reactive oxygen species (ROS) formed during hypoxia play an important role in the induction of protective cardiac phenotype. On the other hand, the excess of ROS can contribute to tissue damage caused by I/R. Here we investigated the relationship between myocardial tolerance to I/R injury and transcription activity of major antioxidant genes, transcription factors, and oxidative stress in three different regimens of chronic hypoxia. Adult male Wistar rats were exposed to continuous normobaric hypoxia (FIO 2 0.1) either continuously (CNH) or intermittently for 8 h/day (INH8) or 23 h/day (INH23) for 3 wk period. A control group was kept in room air. Myocardial infarct size was assessed in anesthetized open-chest animals subjected to 20 min coronary artery occlusion and 3 h reperfusion. Levels of mRNA transcripts and the ratio of reduced and oxidized glutathione (GSH/GSSG) were analyzed by real-time RT-PCR and by liquid chromatography, respectively. Whereas CNH as well as INH8 decreased infarct size, 1 h daily reoxygenation (INH23) abolished the cardioprotective effect and decreased GSH/GSSG ratio. The majority of mRNAs of antioxidant genes related to mitochondrial antioxidant defense (manganese superoxide dismutase, glutathione reductase, thioredoxin/thioredoxin reductase, and peroxiredoxin 2) were upregulated in both cardioprotective regimens (CNH, INH8). In contrast, INH23 increased only PRX5, which was not sufficient to induce the cardioprotective phenotype. Our results suggest that the increased mitochondrial antioxidant defense plays an important role in cardioprotection afforded by chronic hypoxia. adaptation to hypoxia; cardioprotection; ischemia-reperfusion injury; oxidative stress; antioxidant defense ADAPTATION TO CHRONIC HYPOXIA may improve cardiac tolerance to acute ischemia-reperfusion (I/R) injury under certain conditions. Whereas chronic continuous hypoxia induces a protective cardiac phenotype, a brief daily interruption of hypoxic adaptation for 1 h eliminates the protective effect (31). Tissue damage caused by I/R insult is tightly related to the excess of reactive oxygen species (ROS), but the exact molecular mechanism underlying these adverse effects is still not fully elucidated. Intracellular ROS initiate a sequence of oxidation reactions that can seriously damage cell structures. ROS differ in their reactivity, as well as in mechanisms and sites of their production. These harmful species can be eliminated by specific scavengers. If production of ROS exceeds the capacity limit of antioxidant systems or if the systemic capacity is insufficient, the level of ROS in individual cell compartments increases and generates ...

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confidence: 99%

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confidence: 99%

Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems

Kasparova

Neckář

Dabrowská

et al. 2015

Physiological Genomics

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“…Under oxidative stress conditions, a cellular adaptive response may take place in order to counteract the deleterious effects of oxidative stress (Lushchak, 2011;Schulke, 2012). The adaptive response to oxidative challenges is mediated by the transcription factor Nrf2 through the antioxidant response element (ARE).…”

Section: Discussionmentioning

confidence: 99%

“…The adaptive response to oxidative challenges is mediated by the transcription factor Nrf2 through the antioxidant response element (ARE). Once oxidative stress signals are generated, Nrf2 triggers the transcription of endogenous antioxidant enzymes as glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), NAD(P)H oxidase, NADPH quinine oxidoreductase (NQO-1), glutamate-cysteine ligase (GCL) and thioredoxin system through its binding to the DNA sites known as the antioxidant responsive element "ARE" (Lushchak, 2011;Schulke, 2012). We observed a significant increase in the activity of CAT, SOD and GST in tadpoles captured at S2 site ( Figure 4).…”

Section: Discussionmentioning

confidence: 99%

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The Brazilian Pampa biome is currently under constant threat due to increase of agriculture and improper management of urban effluents. Studies with focus on the assessment of impacts caused by human activities in this biome are scarce. In the present study we measured stress-related biomarkers in tadpoles of the leaf frog Phyllomedusa iheringii, an endemic species to the Pampa biome, and tested its suitability as a bioindicator for the assessment of potential aquatic contamination in selected ponds (S1 and S2) nearby agricultural areas in comparison to a reference site. A significant decrease in acetylcholinesterase activity was observed in S2 when compared to S1 and reference. The levels of total-hydroperoxides were increased in S2 site. In parallel, increased activity of the antioxidant enzymes catalase, superoxide dismutase and glutathione S-transferase were observed in S2 when compared to S1 and reference. Further studies are necessary in order to correlate the changes observed here with different chemical stressors in water, as well as to elucidate mechanisms of toxicity induced by pesticides in amphibian species endemic to the Pampa biome. Nevertheless, our study validates Phyllomedusa iheringii as a valuable bioindicator in environmental studies.PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.776v2 | CC BY 4.0 Open Access |

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“…Estes têm sido descritos para uma variedade de organismos (Fu et al, 2012;Schülke et al, 2012;Klanian, 2013;Zhang et al, 2015), incluindo cnidários aposimbiônticos (Teixeira et al, 2013). Em organismos fotossintéticos, grande parte dos processos fisiológicos e comportamentais estão relacionados com os ciclos físicos diurnos relacionados com a exposição à luz (Kühl et al, 1995;Yacobovitch et al, 2004;Hernando, 2016;Millar, 2016).…”

Section: Preparação Fisiológica Para O Estresse Oxidativounclassified

Processos fisiológicos envolvidos na aquisição, perda e recolocação da zooxantela ligados ao branqueamento de cnidários

Casillas-Barragán¹

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Living with stress: Regulation of antioxidant defense genes in the subterranean, hypoxia-tolerant mole rat, Spalax

Cited by 66 publications

References 82 publications

Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems

Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems

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Processos fisiológicos envolvidos na aquisição, perda e recolocação da zooxantela ligados ao branqueamento de cnidários

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