Search results for "oxidative phosphorylation"
showing 10 items of 284 documents
Mitochondrial function and energy metabolism in neuronal HT22 cells resistant to oxidative stress
2014
Background and Purpose The hippocampal cell line HT22 is an excellent model for studying the consequences of endogenous oxidative stress. Extracellular glutamate depletes cellular glutathione by blocking the glutamate/cystine antiporter system xc−. Glutathione depletion induces a well-defined programme of cell death characterized by an increase in reactive oxygen species and mitochondrial dysfunction. Experimental Approach We compared the mitochondrial shape, the abundance of mitochondrial complexes and the mitochondrial respiration of HT22 cells, selected based on their resistance to glutamate, with those of the glutamate-sensitive parental cell line. Key Results Glutamate-resistant mitoch…
The effect of sea water on cytochrome oxidase and oxidative phosphorylation.
1961
Piccole quantita di acqua di mare causano una forte inibizione della fosforilazione ossidativa, mentre l'effetto sulla attivita citocromossidasica e piuttosto modesto. L'ione responsabile di questo effetto e il Calcio.
Cold exposure enhances fat utilization but not non-esterified fatty acids, glycerol or catecholamines availability during submaximal walking and runn…
2013
Cold exposure modulates the use of carbohydrates and fat during exercise. This phenomenon has mostly been observed in controlled cycling studies, but not during walking and running when core temperature and oxygen consumption are controlled, as both may alter energy metabolism. This study aimed at examining energy substrate availability and utilization during walking and running in the cold when core temperature and oxygen consumption are maintained. Ten lightly clothed male subjects walked or ran for 60-min, at 50% and 70% of maximal oxygen consumption, respectively, in a climatic chamber set at 0°C or 22°C. Thermal, cardiovascular, and oxidative responses were measured every 15-…
Cytotoxic effects of oxysterols associated with human diseases: Induction of cell death (apoptosis and/or oncosis), oxidative and inflammatory activi…
2009
Oxysterols resulting from spontaneous or enzymatic oxidation of cholesterol are present in numerous foodstuffs and have been identified at increased levels in the plasma and the vascular walls of patients with cardiovascular diseases, especially in atherosclerotic lesions. Consequently, their role in lipid disorders is widely suspected, but they may also contribute to the development of important degenerative diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, osteoporosis, age-related macular degeneration, and cataract. Since these pathologies can be associated with the presence of apoptotic cells, oxidative and inflammatory processes, and lipid disorders, the ab…
Side effects of oxysterols: cytotoxicity, oxidation, inflammation, and phospholipidosis.
2008
Oxysterols are 27-carbon atom molecules resulting from autoxidation or enzymatic oxidation of cholesterol. They are present in numerous foodstuffs and have been demonstrated to be present at increased levels in the plasma of patients with cardiovascular diseases and in atherosclerotic lesions. Thus, their role in lipid disorders is widely suspected, and they might also be involved in important degenerative diseases such as Alzheimer's disease, osteoporosis, and age-related macular degeneration. Since atherosclerosis is associated with the presence of apoptotic cells and with oxidative and inflammatory processes, the ability of some oxysterols, especially 7-ketocholesterol and 7β-hydrox…
Saccharomyces cerevisiae Cytosolic Thioredoxins Control Glycolysis, Lipid Metabolism, and Protein Biosynthesis under Wine-Making Conditions.
2019
Thioredoxins are small proteins that regulate the cellular redox state, prevent oxidative damage, and play an active role in cell repair. Oxidative stress has proven to be of much relevance in biotechnological processes when the metabolism of Saccharomyces cerevisiae is mainly respiratory. During wine yeast starter production, active dry yeast cytosolic thioredoxin Trx2p is a key player in protecting metabolic enzymes from being oxidized by carbonylation. Less is known about the role of redox control during grape juice fermentation. A mutant strain that lacked both cytosolic thioredoxins, Trx1p and Trx2p, was tested for grape juice fermentation. Its growth and sugar consumption were greatly…
Mitochondrial proteomics profile points oxidative phosphorylation as main target for beauvericin and enniatin B mixture
2020
Abstract Beauvericin (BEA) and enniatin B (EN B) are non-legislated Fusarium mycotoxins usually found in cereal and cereal-based products all around the world. By the proteomic analysis of mitochondria enriched extracts from Jurkat cells exposed for 24 h to three concentrations of BEA:EN B (0.01–0.1–0.5 μM), a number of 1821 proteins (202 mitochondrial) were identified and relatively quantified. 340 proteins (59 mitochondrial) were statistically significant altered in our samples (Anova p-value ≤ 0.05 and fold change (FC) ≥1.5). The protein mitochondrial translational release factor 1 like (MTRF1L) was the most abundant protein in the three mycotoxin exposures studied. The mycotoxins mixtur…
Mitochondrial complex I: new insights from inhibitor assays
2000
The NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial respiratory chain is by far the most complicated of the proton-translocating enzymes involved in the oxidative phosphorylation. Many clues regarding both electron transfer and proton translocation are still unknown. In this sense, inhibitor assays are relevant and useful pieces for elaborating a suitable model to explain the elusive bioenergetic mechanism of this enzyme. This short review presents the most recent advances in inhibitor studies and highlights the major controversies.
Oxidative Stress and Respiratory System: Pharmacological and Clinical Reappraisal of N-Acetylcysteine
2014
Abstract The large surface area for gas exchange makes the respiratory system particularly susceptible to oxidative stress-mediated injury. Both endogenous and exogenous pro-oxidants (e.g. cigarette smoke) trigger activation of leukocytes and host defenses. These mechanisms interact in a ìmultilevel cycleî responsible for the control of the oxidant/antioxidant homeostasis. Several studies have demonstrated the presence of increased oxidative stress and decreased antioxidants (e.g. reduced glutathione [GSH]) in subjects with chronic obstructive pulmonary disease (COPD), but the contribution of oxidative stress to the pathophysiology of COPD is generally only minimally discussed. The aim of t…
Oxidative and nitrosative stress in the diaphragm of patients with COPD.
2007
COPD is associated with an increased load on the diaphragm. Since chronic muscle loading results in changes in antioxidant capacity and formation of reactive oxygen and reactive nitrogen species, we hypothesized that COPD has a similar effect on the diaphragm, which is related to the severity of COPD. Catalase activity was determined spectrophotometrically. Levels of 4-hydroxy-2-nonenal (HNE)-protein adducts and 3-nitrotyrosine (NT) formation were measured using western blotting. Levels of malondialdehyde (MDA) were assessed by high-performance liquid chromatography. We found that catalase activity was approximately 89% higher in the diaphragm of severe COPD patients (FEV1 37+/-5% predicted…