Search results for "Redox"
showing 10 items of 619 documents
Time-course of thiol oxidation of protein phosphatases during cerulein-induced acute pancreatitis
2018
Acute pancreatitis (AP) is an acute inflammatory process of the pancreatic gland. The aim of this work was to evaluate the role of thiol oxidation of key proteins that can be involved in the regulation of the inflammatory process during AP. AP was induced in C57BL/6 mice by 7 hourly subcutaneous injections of cerulein (50 ug/kg bw). Animals were sacrificed after 1, 3, 5 and 7 injections of cerulein. One hour after the first injection, hyperoxidation of peroxiredoxin 1–4 was detected coinciding with a H2O2 peak. Three hours later, a marked up-regulation of mRNA and protein expression of sulfiredoxin, partially mediated by Nrf-2, takes place. The up-regulation of sulfiredoxin seems to be resp…
The role of mitochondrial reactive oxygen species, NO and H2S in ischaemia/reperfusion injury and cardioprotection
2020
Redox signalling in mitochondria plays an important role in myocardial ischaemia/reperfusion (I/R) injury and in cardioprotection. Reactive oxygen and nitrogen species (ROS/RNS) modify cellular structures and functions by means of covalent changes in proteins including among others S‐nitros(yl)ation by nitric oxide (NO) and its derivatives, and S‐sulphydration by hydrogen sulphide (H2S). Many enzymes are involved in the mitochondrial formation and handling of ROS, NO and H2S under physiological and pathological conditions. In particular, the balance between formation and removal of reactive species is impaired during I/R favouring their accumulation. Therefore, various interventions aimed a…
Reactions of Flavonoids with o‑Quinones Interfere with the Spectrophotometric Assay of Tyrosinase Activity
2016
Flavonoids are important food components with antioxidant properties and many of them have been described as tyrosinase inhibitors. Oxidation of quercetin, kaempferol, morin, catechin, and naringenin by mushroom tyrosinase and their influence on the oxidation of l-dopa and l-tyrosine was studied. Reaction rates measured spectrophotometrically and by oxygen consumption differed substantially. All tested flavonoids reacted with 4-tert-butyl-o-benzoquinone and/or 4-methyl-o-benzoquinone, although at different rates. These reactions generated products whose UV-vis spectra either overlapped or did not overlap with the spectrum of dopachrome. They therefore strongly influence the kinetic analysis…
Oxidative signature of cerebrospinal fluid from mild cognitive impairment and Alzheimer disease patients
2015
Abstract Background Several studies suggest that pathological changes in Alzheimer’s disease (AD) brain begin around 10–20 years before the onset of cognitive impairment. Biomarkers that can support early diagnosis and predict development of dementia would, therefore, be crucial for patient care and evaluation of drug efficacy. Although cerebrospinal fluid (CSF) levels of Aβ42, tau, and p-tau are well-established diagnostic biomarkers of AD, there is an urgent need to identify additional molecular alterations of neuronal function that can be evaluated at the systemic level. Objectives This study was focused on the analysis of oxidative stress-related modifications of the CSF proteome, from …
Free-energy studies reveal a possible mechanism for oxidation-dependent inhibition of MGL
2016
AbstractThe function of monoacylglycerol lipase (MGL), a key actor in the hydrolytic deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2AG), is tightly controlled by the cell’s redox state: oxidative signals such as hydrogen peroxide suppress MGL activity in a reversible manner through sulfenylation of the peroxidatic cysteines, C201 and C208. Here, using as a starting point the crystal structures of human MGL (hMGL), we present evidence from molecular dynamics and metadynamics simulations along with high-resolution mass spectrometry studies indicating that sulfenylation of C201 and C208 alters the conformational equilibrium of the membrane-associated lid domain of MGL to favo…
Thioredoxin and Glutaredoxin Systems as Potential Targets for the Development of New Treatments in Friedreich’s Ataxia
2020
The thioredoxin family consists of a small group of redox proteins present in all organisms and composed of thioredoxins (TRXs), glutaredoxins (GLRXs) and peroxiredoxins (PRDXs) which are found in the extracellular fluid, the cytoplasm, the mitochondria and in the nucleus with functions that include antioxidation, signaling and transcriptional control, among others. The importance of thioredoxin family proteins in neurodegenerative diseases is gaining relevance because some of these proteins have demonstrated an important role in the central nervous system by mediating neuroprotection against oxidative stress, contributing to mitochondrial function and regulating gene expression. Specifical…
Activin Receptor Ligand Blocking and Cancer Have Distinct Effects on Protein and Redox Homeostasis in Skeletal Muscle and Liver
2019
Muscle wasting in cancer cachexia can be alleviated by blocking activin receptor type 2 (ACVR2) ligands through changes in protein synthesis/degradation. These changes in cellular and protein metabolism may alter protein homeostasis. First, we elucidated the acute (1–2 days) and 2-week effects of blocking ACVR2 ligands by soluble activin receptor 2B (sACVR2B-Fc) on unfolded protein response (UPR), heat shock proteins (HSPs) and redox balance in a healthy mouse skeletal muscle. Second, we examined UPR, autophagy and redox balance with or without sACVR2B-Fc administration in muscle and liver of C26 tumor-bearing mice. The indicators of UPR and HSPs were not altered 1–2 days after a single sAC…
MicroRNAs and Oxidative Stress: An Intriguing Crosstalk to Be Exploited in the Management of Type 2 Diabetes
2021
Type 2 diabetes is a chronic disease widespread throughout the world, with significant human, social, and economic costs. Its multifactorial etiology leads to persistent hyperglycemia, impaired carbohydrate and fat metabolism, chronic inflammation, and defects in insulin secretion or insulin action, or both. Emerging evidence reveals that oxidative stress has a critical role in the development of type 2 diabetes. Overproduction of reactive oxygen species can promote an imbalance between the production and neutralization of antioxidant defence systems, thus favoring lipid accumulation, cellular stress, and the activation of cytosolic signaling pathways, and inducing β-cell dysfunction, insul…
Taking up the cudgels for the traditional reactive oxygen and nitrogen species detection assays and their use in the cardiovascular system
2017
Reactive oxygen and nitrogen species (RONS such as H2O2, nitric oxide) confer redox regulation of essential cellular functions (e.g. differentiation, proliferation, migration, apoptosis), initiate and catalyze adaptive stress responses. In contrast, excessive formation of RONS caused by impaired break-down by cellular antioxidant systems and/or insufficient repair of the resulting oxidative damage of biomolecules may lead to appreciable impairment of cellular function and in the worst case to cell death, organ dysfunction and severe disease phenotypes of the entire organism. Therefore, the knowledge of the severity of oxidative stress and tissue specific localization is of great biological …
Insights into the inhibited form of the redox-sensitive SufE-like sulfur acceptor CsdE
2017
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