Search results for "REACTIVE OXYGEN SPECIES"
showing 10 items of 879 documents
Redox state alteration modulates astrocyte glucuronidation.
2004
We have investigated the effects of mild oxidative conditions on drug-metabolizing enzyme activity in rat cultured astrocytes. These experimental conditions promoting an oxidative environment were obtained by short exposure to a low concentration of menadione (5 microM) for a short duration (15 min). This resulted in the rapid and transient production of reactive oxygen species (+130%), associated with a decrease in GSH cellular content (-24%), and an increase in total protein oxidation (+26%), but promoted neither PGE(2) nor NO production. This treatment induced a rapid and persistent decrease in astrocyte glucuronidation activities, which was totally prevented by N-acetyl-l-cysteine. Thes…
Oxidative stress triggers cytokinesis failure in hepatocytes upon isolation
2015
Primary hepatocytes are highly differentiated cells and proliferatively quiescent. However, the stress produced during liver digestion seems to activate cell cycle entry by proliferative/dedifferentiation programs that still remain unclear. The aim of this work was to assess whether the oxidative stress associated with hepatocyte isolation affects cell cycle and particularly cytokinesis, the final step of mitosis. Hepatocytes were isolated from C57BL/6 mice by collagenase perfusion in the absence and presence of N-acetyl cysteine (NAC). Polyploidy, cell cycle, and reactive oxygen species (ROS) were studied by flow cytometry (DNA, phospho-histone 3, and CellROX(®) Deep Red) and Western blott…
Increased radiation from Chernobyl decreases the expression of red colouration in natural populations of bank voles (Myodes glareolus)
2014
AbstractPheomelanin is a pink to red version of melanin pigment deposited in skin and hair. Due to its bright colour, pheomelanin plays a crucial function in signalling, in particular sexual signalling. However, production of pheomelanin, as opposed to its dark alternative, eumelanin, bears costs in terms of consumption of antioxidants important for protection of DNA against naturally produced reactive oxidative species. Therefore, decreased expression of pheomelanin is expected in organisms exposed to severe oxidative stress such as that caused by exposure to chronic ionizing radiation. We tested if variable exposure to radiation among natural populations of bank voles Myodes glareolus in …
Inhibition of cancer growth by resveratrol is related to its low bioavailability.
2002
The relationship between resveratrol (RES) bioavalability and its effect on tumor growth was investigated. Tissue levels of RES were studied after i.v. and oral administration of trans-resveratrol (t-RES) to rabbits, rats, and mice. Half-life of RES in plasma, after i.v. administration of 20 mg t-RES/kg b.wt., was very short (e.g., 14.4 min in rabbits). The highest concentration of RES in plasma, either after i.v. or oral administration (e.g., 2.6 +/- 1.0 microM in mice 2.5 min after receiving 20 mg t-RES/kg orally), was reached within the first 5 min in all animals studied. Extravascular levels (brain, lung, liver, and kidney) of RES, which paralleled those in plasma, were always1 nmol/g f…
Heme oxygenase-1: a novel key player in the development of tolerance in response to organic nitrates.
2007
Objective— Nitrate tolerance is likely attributable to an increased production of reactive oxygen species (ROS) leading to an inhibition of the mitochondrial aldehyde dehydrogenase (ALDH-2), representing the nitroglycerin (GTN) and pentaerythrityl tetranitrate (PETN) bioactivating enzyme, and to impaired nitric oxide bioactivity and signaling. We tested whether differences in their capacity to induce heme oxygenase-1 (HO-1) might explain why PETN and not GTN therapy is devoid of nitrate and cross-tolerance. Methods and Results— Wistar rats were treated with PETN or GTN (10.5 or 6.6 μg/kg/min for 4 days). In contrast to GTN, PETN did not induce nitrate tolerance or cross-tolerance as assess…
Molecular basis of endothelial dysfunction in sepsis.
2003
Sepsis is one of the major causes of mortality in critically ill patients and develops as a result of the host response to infection. A complex network of events is set into motion in the body by the infection and results in the pathogenesis of sepsis. This review article focuses on the molecular mechanisms and components involved in the pathogenesis of sepsis with a major emphasis on the endothelium. This includes sepsis-inducing bacterial components (e.g. endotoxins), cellular targets of these molecules and their responses, host reactions, intracellular and cytokine networks, individual susceptibility and new therapeutic targets in sepsis treatment.
Importance of mitochondrial dynamin-related protein 1 in hypothalamic glucose sensitivity in rats.
2012
International audience; AIMS: Hypothalamic mitochondrial reactive oxygen species (mROS)-mediated signaling has been recently shown to be involved in the regulation of energy homeostasis. However, the upstream signals that control this mechanism have not yet been determined. Here, we hypothesize that glucose-induced mitochondrial fission plays a significant role in mROS-dependent hypothalamic glucose sensing. RESULTS: Glucose-triggered translocation of the fission protein dynamin-related protein 1 (DRP1) to mitochondria was first investigated in vivo in hypothalamus. Thus, we show that intracarotid glucose injection induces the recruitment of DRP1 to VMH mitochondria in vivo. Then, expressio…
Increased Oxidative Damage Associated with Unfavorable Cytogenetic Subgroups in Chronic Lymphocytic Leukemia
2014
Oxidative stress contributes to genomic instability in chronic lymphocytic leukemia (CLL), but its relationship with the acquisition of specific chromosomal abnormalities is unknown. We recruited 55 untreated CLL patients and assessed 8-oxo-2′-deoxyguanosine (8-oxo-dG), glutathione, and malondialdehyde (MDA) levels, and we compared them among the cytogenetic subgroups established using fluorescence in situ hybridization (FISH). Significant increases in 8-oxo-dG and/or MDA were observed in patients with unfavorable cytogenetic aberrations (17p and 11q deletions) compared to the 13q deletion group.TP53deletion patients exhibited a diminished DNA repair efficiency. Finally, cases with normal F…
Anti-inflammatory and antioxidant effects of muscarinic acetylcholine receptor (mAChR) activation in the rat hippocampus
2019
AbstractRecently we found that acute treatment with Oxotremorine (Oxo), a non-selective mAChRs agonist, up-regulates heat shock proteins and activates their transcription factor heat shock factor 1 in the rat hippocampus. Here we aimed to investigate: a) if acute treatment with Oxo may regulate pro-inflammatory or anti-inflammatory cytokines and oxidative stress in the rat hippocampus; b) if chronic restraint stress (CRS) induces inflammatory or oxidative alterations in the hippocampus and whether such alterations may be affected by chronic treatment with Oxo. In the acute experiment, rats were injected with single dose of Oxo (0.4 mg/kg) and sacrificed at 24 h, 48 h and 72 h. In the CRS ex…
Inflammation-Induced Alteration of Astrocyte Mitochondrial Dynamics Requires Autophagy for Mitochondrial Network Maintenance
2013
Accumulating evidence suggests that changes in the metabolic signature of astrocytes underlie their response to neuroinflammation, but how proinflammatory stimuli induce these changes is poorly understood. By monitoring astrocytes following acute cortical injury, we identified a differential and region-specific remodeling of their mitochondrial network: while astrocytes within the penumbra of the lesion undergo mitochondrial elongation, those located in the core-the area invaded by proinflammatory cells-experience transient mitochondrial fragmentation. In brain slices, proinflammatory stimuli reproduced localized changes in mitochondrial dynamics, favoring fission over fusion. This effect w…