Search results for "Oxidation"

Paraoxonase-2 regulates coagulation activation through endothelial tissue factor

2017

Oxidative stress and inflammation of the vessel wall contribute to prothrombotic states. The antioxidative protein paraoxonase-2 (PON2) shows reduced expression in human atherosclerotic plaques and endothelial cells in particular. Supporting a direct role for PON2 in cardiovascular diseases, Pon2 deficiency in mice promotes atherogenesis through incompletely understood mechanisms. Here, we show that deregulated redox regulation in Pon2 deficiency causes vascular inflammation and abnormalities in blood coagulation. In unchallenged Pon2-/- mice, we find increased oxidative stress and endothelial dysfunction. Bone marrow transplantation experiments and studies with endothelial cells provide ev…

Effects of UV filter 4-methylbenzylidene camphor during early development of Solea senegalensis Kaup, 1858

2018

Abstract The inclusion of organic UV filters in personal care products (PCPs) has increased in recent years. 4-Methylbenzylidene camphor (4MBC) is one of the most used UV filters, and thus it is commonly found in aquatic ecosystems, with proved negative effects on aquatic organisms. Effects on early life stages of marine vertebrates are largely unknown. Therefore, the main goal of this work was to evaluate 4MBC effects on Senegalese sole (Solea Senegalensis Kaup, 1858) larvae at different levels of biological organization. S. senegalensis were exposed to increasing concentrations of 4MBC from egg stage until 96 h. Mortality, growth, malformations, behaviour and biochemical responses, includ…

7-Keto-Cholesterol and Cholestan-3beta, 5alpha, 6beta-Triol Induce Eryptosis through Distinct Pathways Leading to NADPH Oxidase and Nitric Oxide Synt…

2019

Background/aims We showed that patho-physiological concentrations of either 7-keto-cholesterol (7-KC), or cholestane-3beta, 5alpha, 6beta-triol (TRIOL) caused the eryptotic death of human red blood cells (RBC), strictly dependent on the early production of reactive oxygen species (ROS). The goal of the current study was to assess the contribution of the erythrocyte ROS-generating enzymes, NADPH oxidase (RBC-NOX), nitric oxide synthase (RBC-NOS) and xanthine oxido-reductase (XOR) to the oxysterol-dependent eryptosis and pertinent activation pathways. Methods Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, reactive oxygen/nitrogen species (RONS) and nitri…

Optimization of antioxidants extraction from peanut skin to prevent oxidative processes during soybean oil storage

2017

8 páginas, 3 figuras, 2 tablas

Prooxidative chain transfer activity by thiol groups in biological systems

2020

Cysteine is arguably the best-studied biological amino acid, whose thiol group frequently participates in catalysis or ligand binding by proteins. Still, cysteine's unusual biological distribution has remained mysterious, being strikingly underrepresented in transmembrane domains and on accessible protein surfaces, particularly in aerobic life forms (“cysteine anomaly”). Noting that lipophilic thiols have been used for decades as radical chain transfer agents in polymer chemistry, we speculated that the rapid formation of thiyl radicals in hydrophobic phases might provide a rationale for the cysteine anomaly. Hence, we have investigated the effects of dodecylthiol and related compounds in i…

Special Issue "Human performance and redox signaling in health and disease".

2016

Redox signaling in the gastrointestinal tract.

2017

Redox signaling regulates physiological self-renewal, proliferation, migration and differentiation in gastrointestinal epithelium by modulating Wnt/β-catenin and Notch signaling pathways mainly through NADPH oxidases (NOXs). In the intestine, intracellular and extracellular thiol redox status modulates the proliferative potential of epithelial cells. Furthermore, commensal bacteria contribute to intestine epithelial homeostasis through NOX1- and dual oxidase 2-derived reactive oxygen species (ROS). The loss of redox homeostasis is involved in the pathogenesis and development of a wide diversity of gastrointestinal disorders, such as Barrett's esophagus, esophageal adenocarcinoma, peptic ulc…

Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two…

2017

The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42−, NO3−, Fe3+, Mn4+, O2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4-oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3.4% and 0.5% of archaeal and bacterial 16S rRNA genes, respectively), likely due to the low environmental stability associated with shallow depths.…

Oxidative stress and exceptional human longevity: Systematic review.

2020

Oxidative stress (OS) has been previously linked to the aging process, as have some diseases and geriatric syndromes as frailty and sarcopenia. The aim of the present study was to perform a systematic review on oxidative stress activity and extreme longevity in humans.We conducted a systematic literature review following the PRISMA guidelines. Observational studies assessing OS-biomarkers and/or antioxidants in long-lived individuals (97 years old or over) comparing them to those of one or more age groups, (at least one of which from comprising elderly subjects) were considered for inclusion. A narrative synthesis was planned. Quality of selected studies was assessed using the Newcastle-Ott…

Singlet Oxygen Attack on Guanine: Reactivity and Structural Signature within the B-DNA Helix

2016

International audience; Oxidatively generated DNA lesions are numerous and versatile, and have been the subject of intensive research since the discovery of 8-oxoguanine in 1984. Even for this prototypical lesion, the precise mechanism of formation remains elusive due to the inherent difficulties in characterizing high-energy intermediates. We have probed the stability of the guanine endoperoxide in B-DNA as a key intermediate and determined a unique activation free energy of around 6 kcal mol−1 for the formation of the first C−O covalent bond upon the attack of singlet molecular oxygen (1O2) on the central guanine of a solvated 13 base-pair poly(dG-dC), described by means of quantum mechan…