Search results for "nitrate"
showing 10 items of 580 documents
Characterization of NO-Induced Nitrosative Status in Human Placenta from Pregnant Women with Gestational Diabetes Mellitus
2017
Dysregulation of NO production is implicated in pregnancy-related diseases, including gestational diabetes mellitus (GDM). The role of NO and its placental targets in GDM pregnancies has yet to be determined. S-Nitrosylation is the NO-derived posttranslational protein modification that can modulate biological functions by forming NO-derived complexes with longer half-life, termed S-nitrosothiol (SNO). Our aim was to examine the presence of endogenous S-nitrosylated proteins in cysteine residues in relation to antioxidant defense, apoptosis, and cellular signal transduction in placental tissue from control (n=8) and GDM (n=8) pregnancies. S-Nitrosylation was measured using the biotin-switch …
Vascular biotransformation of organic nitrates is independent of cytochrome P450 monooxygenases
2020
Background and Purpose Organic nitrates such as nitroglycerin (NTG) or pentaerythritol tetranitrate (PETN) have been used for over a century in the treatment of angina or ischaemic heart disease. These compounds are prodrugs which release their nitrovasodilators upon enzymic bioactivation by aldehyde dehydrogenase (ALDH2) or cytochromes P450 (CYP). Whereas ALDH2 is known to directly activate organic nitrates in vessels, the contribution of vascular CYPs is unknown and was studied here. Experimental Approach As all CYPs depend on cytochrome P450 reductase (POR) as electron donor, we generated a smooth muscle cell-specific, inducible knockout mouse of POR (smcPOR−/−) to investigate the contri…
Exploration of Fas S-Nitrosylation by the Biotin Switch Assay
2017
International audience; S-nitrosylation is the covalent attachment of nitric oxide radical to the thiol side chain of cysteine. The death receptor Fas/CD95 can be S-nitrosylated in cancer cell lines by NO donors or iNOS activation. This posttranslational modification (PTM) induces Fas aggregation into lipid rafts and enhances FasL-mediated signaling and apoptosis. In this report, we describe the detection of Fas S-nitrosylation by the most commonly used method, the biotin switch assay (BSA) technique, that allows the detection of this very labile covalent modification in cells or tissues. Briefly, this technique relies on the ability of ascorbate to reduce the covalent bond between the NO r…
Staining SDS-PAGE gels of skeletal matrices after western blot: a way to improve their sharpness.
2015
7 pages; International audience; Denaturing 1D electrophoresis on acrylamide gels - also referred as SDS-PAGE - is a classical technique for fractionating and visualizing the macromolecular constituents of matrices associated to calcified tissues. This technique has been widely used in association with the subsequent silver nitrate staining. But because matrices associated to calcified tissues are very often glycosylated and constituted of numerous polydisperse macromolecules, the obtained pattern is frequently 'smeary' and discrete bands, when present on the gel, are often blurred, thickened or totally masked by the polydisperse macromolecules. In this paper, we present a simple protocol t…
Rabphilin involvement in filtration and molecular uptake in Drosophila nephrocytes suggests a similar role in human podocytes
2020
ABSTRACT Drosophila nephrocytes share functional, structural and molecular similarities with human podocytes. It is known that podocytes express the rabphilin 3A (RPH3A)-RAB3A complex, and its expression is altered in mouse and human proteinuric disease. Furthermore, we previously identified a polymorphism that suggested a role for RPH3A protein in the development of urinary albumin excretion. As endocytosis and vesicle trafficking are fundamental pathways for nephrocytes, the objective of this study was to assess the role of the RPH3A orthologue in Drosophila, Rabphilin (Rph), in the structure and function of nephrocytes. We confirmed that Rph is required for the correct function of the en…
Protein-bound tyrosine oxidation, nitration and chlorination by-products assessed by ultraperformance liquid chromatography coupled to tandem mass sp…
2015
Abstract Background Free radicals cause alterations in cellular protein structure and function. Oxidized, nitrated, and chlorinated modifications of aromatic amino acids including phenylalanine and tyrosine are reliable biomarkers of oxidative stress and inflammation in clinical conditions. Objective To develop, validate and apply a rapid method for the quantification of known hallmarks of tyrosine oxidation, nitration and chlorination in plasma and tissue proteins providing a snapshot of the oxidative stress and inflammatory status of the organism and of target organs respectively. Material and Methods The extraction and clean up procedure entailed protein precipitation, followed by protei…
Oral health and systemic inflammatory, cardiac and nitroxid biomarkers in hemodialysis patients.
2016
Background Periodontal diseases have systemic inflammatory effects and have been adversely associated with cardiovascular diseases, which are also the most frequent cause of death in the end-stage renal disease. The aim of this cross-sectional study was to investigate the oral health and serum biomarkers among the hemodialysis (HD) patients in Slovenia. Material and Methods 111 HD patients were periodontally examined and their sera were assayed for C reactive protein (CRP), cardiac troponin T (TnT), nitrite/nitrate (NOx) and antibody levels to A. actinomycetemcomitans and P. gingivalis. The association of oral health with systemic response was analyzed with Kruskal-Wallis test, Fisher’s exa…
Methanotrophy under Versatile Conditions in the Water Column of the Ferruginous Meromictic Lake La Cruz (Spain)
2016
Lakes represent a considerable natural source of methane to the atmosphere compared to their small global surface area. Methanotrophs in sediments and in the water column largely control methane fluxes from these systems, yet the diversity, electron accepting capacity, and nutrient requirements of these microorganisms have only been partially identified. Here, we investigated the role of electron acceptors alternative to oxygen and sulfate in microbial methane oxidation at the oxycline and in anoxic waters of the ferruginous meromictic Lake La Cruz, Spain. Active methane turnover in a zone extending well below the oxycline was evidenced by stable carbon isotope-based rate measurements. We o…
In vivo effect of N-ethylmaleimide (NEM) on the measurement of nitrate in plasma
2016
Bioavailability of nitric oxide in the body may be estimated by measuring the concentration of nitrate in plasma. However, it has not been reported whether sequestering of aminothiols in plasma affects the concentration of nitrate in the samples.N-ethylmaleimide (NEM) sequesters aminothiols in plasma therefore we tested the in vivo effect of NEM on the concentration nitrate in plasma.Blood samples were collected from 56 healthy subjects in EDTA vials, EDTA vials containing PBS (pH7.4) and EDTA vials containing NEM dissolved in PBS. Nonparametric statistical tests were used to study the effect of NEM on the concentration of nitrate in plasma measured by the Griess reagent assay and by an HPL…
Inorganic nitrite and nitrate in cardiovascular therapy: A better alternative to organic nitrates as nitric oxide donors?
2017
In 1867 the organic nitrite, amyl nitrite, was introduced as a therapeutic agent in the treatment of angina pectoris and was later substituted by the organic nitrate nitroglycerin (NTG). Despite having a highly potent vasodilator capacity in veins>coronary arteries>arterioles, the vasodilator effects NTG are rapidly attenuated by the development of nitrate tolerance. We and others established that NTG treatment stimulates the production of reactive oxygen species such as superoxide and peroxynitrite with subsequent marked attenuation of the NTG vasodilator potency. The nitrite anion (NO2-) has more recently been characterized to possess novel pharmacotherapeutic actions such as modulation o…