Search results for "Dative"

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

2011

Lack of oxygen is life threatening for most mammals. It is therefore of biomedical interest to investigate the adaptive mechanisms which enable mammalian species to tolerate extremely hypoxic conditions. The subterranean mole rat Spalax survives substantially longer periods of hypoxia than the laboratory rat. We hypothesized that genes of the antioxidant defense, detoxifying harmful reactive oxygen species generated during hypoxia and hyperoxia, are involved in Spalax underground adaptation. Using quantitative RT-PCR, we analyzed the mRNA expression levels of seven antioxidant defense genes (catalase, glutathione peroxidase 1, glutathione-S-transferase Pi1, heme oxygenase 1, superoxide dism…

Glutathione peroxidase 1 activity dictates the sensitivity of glioblastoma cells to oxidative stress.

2012

The high intratumoral and intertumoral heterogeneity of glioblastoma (GBM) leads to resistance to different therapies, and hence, selecting an effective therapy is very challenging. We hypothesized that the antioxidant enzyme status is a significant feature of GBM heterogeneity. The most important reactive oxygen/nitrogen species (ROS/RNS) detoxification mechanisms include superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx). Expression and activity of these enzymes and the cellular response to induced oxidative stress were systematically analyzed and compared between GBM cells and nontransformed glial cells of both human and murine origin. Regardless of cell type or speci…

GADD45a physically and functionally interacts with TET1

2015

AbstractDNA demethylation plays a central role during development and in adult physiology. Different mechanisms of active DNA demethylation have been established. For example, Growth Arrest and DNA Damage 45-(GADD45) and Ten-Eleven-Translocation (TET) proteins act in active DNA demethylation but their functional relationship is unresolved. Here we show that GADD45a physically interacts – and functionally cooperates with TET1 in methylcytosine (mC) processing. In reporter demethylation GADD45a requires endogenous TET1 and conversely TET1 requires GADD45a. On GADD45a target genes TET1 hyperinduces 5-hydroxymethylcytosine (hmC) in the presence of GADD45a, while 5-formyl-(fC) and 5-carboxylcyto…

Oxidative stress inhibits IFN-α-induced antiviral gene expression by blocking the JAK–STAT pathway

2006

Abstract BACKGROUND/AIMS: Unresponsiveness to IFN-alpha is common in chronic hepatitis C. Since conditions associated with an increased oxidative stress (advanced age, steatosis, fibrosis, iron overload, and alcohol consumption) reduce the likelihood of response, we hypothesized that oxidative stress may affect the antiviral actions of IFN-alpha. METHODS: We examined in a human hepatocellular carcinoma cell line (Huh-7) the effect of hydrogen peroxide (H2O2), as a generator of oxidative stress, on the IFN-alpha signaling pathway. RESULTS: Pretreatment of Huh-7 cells with 0.5-1 mM H2O2 resulted in the suppression of the IFN-alpha-induced antiviral protein MxA and of IRF-9 mRNA expression. Th…

Oxidative inactivation of mitochondrial creatine kinase: Differential sensitivity of isoforms

2010

Investigations on isomerization and rearrangement of polycyclic arenes under oxidative conditions – Anodic versus reagent-mediated reactions

2019

Abstract Electro-organic conversions at an active molybdenum anode enable the formation of fused arenes. High chemoselectivity was achieved under anodic conditions, and a reagent-induced selectivity was observed by comparison with results of MoCl5-mediated reactions. Polycyclic arenes like phenanthrenes, triphenylenes, chrysenes, or helicenes were selectively obtained in yields up to 87% and in some cases unusual rearrangements were crucial for the product formation.

Aβ and tau toxicities in Alzheimer’s are linked via oxidative stress-induced p38 activation: Protective role of vitamin E

2014

AbstractOxidative stress is a hallmark of Alzheimer’s disease (AD). We propose that rather than causing damage because of the action of free radicals, oxidative stress deranges signaling pathways leading to tau hyperphosphorylation, a hallmark of the disease. Indeed, incubation of neurons in culture with 5 µM beta-amyloid peptide (Aβ) causes an activation of p38 MAPK (p38) that leads to tau hyperphosphorylation. Inhibition of p38 prevents Aβ-induced tau phosphorylation. Aβ-induced effects are prevented when neurons are co-incubated with trolox (the water-soluble analog of vitamin E).We have confirmed these results in vivo, in APP/PS1 double transgenic mice of AD. We have found that APP/PS1 …

P08 Analysis of Nrf2-downstream targets after fumarate treatment in dorsal root ganglia—an anti-inflammatory therapy in neurodegenerative disease?!

2012

Background Dimethylfumarate (DMF) is a new disease modifying therapy. Several studies have shown convincing data after DMF therapy in both autoimmune inflammatory diseases and neurodegenerative disorders like Huntington9s disease (HD). DMF exerts neuroprotective effects via induction of the nuclear factor E2-related factor 2 (Nrf2) and detoxification pathways. Although the exact mechanisms that lead to neurodegeneration are not fully understood the contribution of oxidative stress inducing neurodegeneration is assumed. Aims To analyse the effects of DMF on axonal growth and regeneration and to describe the influence of DMF on the Nrf2-pathway. Methods/techniques We thus investigated the eff…

Cell cycle: Aetiology of age-associated aneuploidy: a mechanism based on the 'free radical theory of ageing'

1995

A general model is put forward to explain the mechanism by which age-associated aneuploidies are produced. This is based on the free radical theory of ageing, which assumes a rise in oxidative stress with age. It is proposed that determination of indicators of oxidative stress in oocytes from various sources could be a first step in the testing of this hypothesis.

Stress-controlled transcription factors, stress-induced genes and stress tolerance in budding yeast.

2000

The transcriptional response to environmental changes is a major topic in both basic and applied research. From a basic point of view, to understand this response includes unravelling how the stress signal is sensed and transduced to the nucleus, to identify which genes are induced under each stress condition and, finally, to establish the phenotypic consequences of this induction in stress tolerance. The possibility of using genetic approaches has made the yeast Saccharomyces cerevisiae a compelling model to study stress response at a molecular level. Moreover, this information can be used to isolate and characterise stress-related proteins in higher eukaryotes and to design strategies to …