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Redox Biology May 2021In the open metabolic system, redox-related signaling requires continuous monitoring and fine-tuning of the steady-state redox set point. The ongoing oxidative... (Review)
Review
In the open metabolic system, redox-related signaling requires continuous monitoring and fine-tuning of the steady-state redox set point. The ongoing oxidative metabolism is a persistent challenge, denoted as oxidative eustress, which operates within a physiological range that has been called the 'Homeodynamic Space', the 'Goldilocks Zone' or the 'Golden Mean'. Spatiotemporal control of redox signaling is achieved by compartmentalized generation and removal of oxidants. The cellular landscape of HO, the major redox signaling molecule, is characterized by orders-of-magnitude concentration differences between organelles. This concentration pattern is mirrored by the pattern of oxidatively modified proteins, exemplified by S-glutathionylated proteins. The review presents the conceptual background for short-term (non-transcriptional) and longer-term (transcriptional/translational) homeostatic mechanisms of stress and stress responses. The redox set point is a variable moving target value, modulated by circadian rhythm and by external influence, summarily denoted as exposome, which includes nutrition and lifestyle factors. Emerging fields of cell-specific and tissue-specific redox regulation in physiological settings are briefly presented, including new insight into the role of oxidative eustress in embryonal development and lifespan, skeletal muscle and exercise, sleep-wake rhythm, and the function of the nervous system with aspects leading to psychobiology.
Topics: Homeostasis; Hydrogen Peroxide; Oxidants; Oxidation-Reduction; Oxidative Stress
PubMed: 33657525
DOI: 10.1016/j.redox.2021.101867 -
Clinical Oral Investigations Jul 2023The aim of this systematic review was to evaluate the prognosis of at-home dental bleaching using low concentration bleaching products. (Review)
Review
OBJECTIVES
The aim of this systematic review was to evaluate the prognosis of at-home dental bleaching using low concentration bleaching products.
MATERIALS AND METHODS
This review was conducted was performed following the recommendations of the 2020 PRISMA statement and was registered in the International Prospective Register of Systematic Reviews (PROSPERO-CRD42022360530). The PICO question was "What is the prognosis of home teeth whitening treatment?". An advanced electronic search was made in three databases: PubMed, Web of Science, and Embase.
RESULTS
The database search led to the retrieval of 225 articles. After elimination of duplicate references, the titles and abstracts of the articles were analyzed with respect to the eligibility criteria, and 24 studies were included for the development of the systematic review.
CONCLUSIONS
Most authors state that the color remains stable between 1 and 2.5 years regardless of the type of bleaching agent or the forms of administration, and color stability in cases of severe discolorations presents a higher degree of recurrence.
CLINICAL RELEVANCE
Given the growing demand for dental cosmetic treatments, the following systematic review may aid the clinician's continuing education and evidence-based practice by providing knowledge on the field of at-home dental bleaching agents and their long-term effects.
Topics: Humans; Hydrogen Peroxide; Tooth Bleaching Agents; Tooth Bleaching; Prognosis; Bleaching Agents
PubMed: 37273018
DOI: 10.1007/s00784-023-05069-0 -
Brazilian Dental Journal Jun 2020There is an increased accessibility of over-the-counter (OTC) whitening agents with very little data in the literature regarding their effectiveness. This review was...
There is an increased accessibility of over-the-counter (OTC) whitening agents with very little data in the literature regarding their effectiveness. This review was done to determine their effectiveness of the predominant OTC whitening agents from 2006 until 2018 where a comparison of each agent was made with a placebo, no treatment or with other OTC whitening agents. The major categories of OTC whitening agents such as dentifrices, whitening strips and paint on gels. Dentist prescribed bleaching applied at home and in-office bleaching studies and studies that demonstrated whitening products to participants were excluded. Articles were searched for in the databases of Medline (Ovid), PubMed, the Cochrane Library and Cochrane Central Register of Controlled Trials. Twenty-four articles were included in the systematic review and the quality of studies was determined by the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) ranking criteria. Compared to other OTC, strips are reported to be effective. Two studies determined whitening strips to be effective. Whitening strips have been shown to be effective when compared with placebos and other OTC whitening agents. Dentifrices are effective in changing the shade of the tooth "by removing extrinsic stains" when compared to a placebo and non-whitening dentifrices, but they are not as effective in comparison to whitening strips. There is a lack of evidence with regards to the effectiveness of paint-on gels. While there is some evidence that OTC can alter shade in the short term, there is a need for better-designed studies.
Topics: Carbamide Peroxide; Humans; Tooth Bleaching; Tooth Bleaching Agents; Tooth Discoloration; Urea
PubMed: 32667517
DOI: 10.1590/0103-6440202003227 -
Circulation Sep 2022Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by high propensity to life-threatening arrhythmias and progressive loss of heart muscle. More...
BACKGROUND
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by high propensity to life-threatening arrhythmias and progressive loss of heart muscle. More than 40% of reported genetic variants linked to ARVC reside in the gene, which encodes the PKP2 protein (plakophilin-2).
METHODS
We describe a comprehensive characterization of the ARVC molecular landscape as determined by high-resolution mass spectrometry, RNA sequencing, and transmission electron microscopy of right ventricular biopsy samples obtained from patients with ARVC with mutations and left ventricular ejection fraction >45%. Samples from healthy relatives served as controls. The observations led to experimental work using multiple imaging and biochemical techniques in mice with a cardiac-specific deletion of studied at a time of preserved left ventricular ejection fraction and in human induced pluripotent stem cell-derived PKP2-deficient myocytes.
RESULTS
Samples from patients with ARVC present a loss of nuclear envelope integrity, molecular signatures indicative of increased DNA damage, and a deficit in transcripts coding for proteins in the electron transport chain. Mice with a cardiac-specific deletion of also present a loss of nuclear envelope integrity, which leads to DNA damage and subsequent excess oxidant production (O and HO), the latter increased further under mechanical stress (isoproterenol or exercise). Increased oxidant production and DNA damage is recapitulated in human induced pluripotent stem cell-derived PKP2-deficient myocytes. Furthermore, PKP2-deficient cells release HO into the extracellular environment, causing DNA damage and increased oxidant production in neighboring myocytes in a paracrine manner. Treatment with honokiol increases SIRT3 (mitochondrial nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-3) activity, reduces oxidant levels and DNA damage in vitro and in vivo, reduces collagen abundance in the right ventricular free wall, and has a protective effect on right ventricular function.
CONCLUSIONS
Loss of nuclear envelope integrity and subsequent DNA damage is a key substrate in the molecular pathology of ARVC. We show transcriptional downregulation of proteins of the electron transcript chain as an early event in the molecular pathophysiology of the disease (before loss of left ventricular ejection fraction <45%), which associates with increased oxidant production (O and HO). We propose therapies that limit oxidant formation as a possible intervention to restrict DNA damage in ARVC.
Topics: Adult; Animals; Arrhythmogenic Right Ventricular Dysplasia; DNA Damage; Humans; Hydrogen Peroxide; Induced Pluripotent Stem Cells; Mice; Mutation; Myocytes, Cardiac; Nuclear Envelope; Oxidants; Plakophilins; Stroke Volume; Ventricular Function, Left
PubMed: 35959657
DOI: 10.1161/CIRCULATIONAHA.122.060454 -
Redox Biology Oct 2022The pathophysiologic significance of redox imbalance is unquestionable as numerous reports and topic reviews indicate alterations in redox parameters during corona virus...
BACKGROUND
The pathophysiologic significance of redox imbalance is unquestionable as numerous reports and topic reviews indicate alterations in redox parameters during corona virus disease 2019 (COVID-19). However, a more comprehensive understanding of redox-related parameters in the context of COVID-19-mediated inflammation and pathophysiology is required.
METHODS
COVID-19 subjects (n = 64) and control subjects (n = 19) were enrolled, and blood was drawn within 72 h of diagnosis. Serum multiplex assays and peripheral blood mRNA sequencing was performed. Oxidant/free radical (electron paramagnetic resonance (EPR) spectroscopy, nitrite-nitrate assay) and antioxidant (ferrous reducing ability of serum assay and high-performance liquid chromatography) were performed. Multivariate analyses were performed to evaluate potential of indicated parameters to predict clinical outcome.
RESULTS
Significantly greater levels of multiple inflammatory and vascular markers were quantified in the subjects admitted to the ICU compared to non-ICU subjects. Gene set enrichment analyses indicated significant enhancement of oxidant related pathways and biochemical assays confirmed a significant increase in free radical production and uric acid reduction in COVID-19 subjects. Multivariate analyses confirmed a positive association between serum levels of VCAM-1, ICAM-1 and a negative association between the abundance of one electron oxidants (detected by ascorbate radical formation) and mortality in COVID subjects while IL-17c and TSLP levels predicted need for intensive care in COVID-19 subjects.
CONCLUSION
Herein we demonstrate a significant redox imbalance during COVID-19 infection affirming the potential for manipulation of oxidative stress pathways as a new therapeutic strategy COVID-19. However, further work is requisite for detailed identification of oxidants (O, HO and/or circulating transition metals such as Fe or Cu) contributing to this imbalance to avoid the repetition of failures using non-specific antioxidant supplementation.
Topics: Antioxidants; COVID-19; Electron Spin Resonance Spectroscopy; Free Radicals; Humans; Hydrogen Peroxide; Intercellular Adhesion Molecule-1; Interleukin-17; Nitrates; Nitrites; Oxidants; Oxidation-Reduction; Oxidative Stress; RNA, Messenger; Uric Acid; Vascular Cell Adhesion Molecule-1
PubMed: 36116160
DOI: 10.1016/j.redox.2022.102465 -
Free Radical Biology & Medicine Nov 2018Oxidants play an important role in the cell and are involved in many redox processes. Oxidant concentrations are maintained through coordinated production and removal... (Review)
Review
Oxidants play an important role in the cell and are involved in many redox processes. Oxidant concentrations are maintained through coordinated production and removal systems. The dysregulation of oxidant homeostasis is a hallmark of many disease pathologies. The local oxidant microdomain is crucial for the initiation of many redox signaling events; however, methods to control oxidant product are limited. Some fluorescent proteins, including GFP, TagRFP, KillerRed, miniSOG, and their derivatives, generate oxidants in response to light. These genetically-encoded photosensitizers produce singlet oxygen and superoxide upon illumination and offer spatial and temporal control over oxidant production. In this review, we will examine the photosensitization properties of fluorescent proteins and their application to redox biology. Emerging concepts of selective oxidant species production via photosensitization and the impact of light on biological systems are discussed.
Topics: Animals; Humans; Light; Luminescent Proteins; Oxidants; Singlet Oxygen
PubMed: 29425690
DOI: 10.1016/j.freeradbiomed.2018.02.002 -
Water Research Apr 2024This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the... (Review)
Review
This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the application of chemical oxidants for micropollutant abatement was assessed by the abatement of the target compounds only. This is controlled by reaction kinetics and therefore, second-order rate constant for these reactions are the pre-requisite to assess the efficiency and feasibility of such processes. Due to the tremendous efforts in this area, we currently have a good experimental data base for second-order rate constants for many chemical oxidants, including radicals. Based on this, predictions can be made for compounds without experimental data with Quantitative Structure Activity Relationships with Hammet/Taft constants or energies of highest occupied molecular orbitals from quantum chemical computations. Chemical oxidation in water treatment has to be economically feasible and therefore, the extent of transformation of micropollutants is often limited and mineralization of target compounds cannot be achieved under realistic conditions. The formation of transformation products from the reactions of the target compounds with chemical oxidants is inherent to oxidation processes and the following questions have evolved over the years: Are the formed transformation products biologically less active than the target compounds? Is there a new toxicity associated with transformation products? Are transformation products more biodegradable than the corresponding target compounds? In addition to the positive effects on water quality related to abatement of micropollutants, chemical oxidants react mainly with water matrix components such as the dissolved organic matter (DOM), bromide and iodide. As a matter of fact, the fraction of oxidants consumed by the DOM is typically > 99%, which makes such processes inherently inefficient. The consequences are loss of oxidation capacity and the formation of organic and inorganic disinfection byproducts also involving bromide and iodide, which can be oxidized to reactive bromine and iodine with their ensuing reactions with DOM. Overall, it has turned out in the last three decades, that chemical oxidation processes are complex to understand and to manage. However, the tremendous research efforts have led to a good understanding of the underlying processes and allow a widespread and optimized application of such processes in water treatment practice such as drinking water, municipal and industrial wastewater and water reuse systems.
Topics: Bromides; Iodides; Water Pollutants, Chemical; Oxidation-Reduction; Oxidants; Water Purification
PubMed: 38387263
DOI: 10.1016/j.watres.2024.121148 -
Environmental Microbiology Feb 2019Reactive oxygen species - superoxide, hydrogen peroxide and hydroxyl radicals - have long been suspected of constraining bacterial growth in important microbial habitats... (Review)
Review
Reactive oxygen species - superoxide, hydrogen peroxide and hydroxyl radicals - have long been suspected of constraining bacterial growth in important microbial habitats and indeed of shaping microbial communities. Over recent decades, studies of paradigmatic organisms such as Escherichia coli, Salmonella typhimurium, Bacillus subtilis and Saccharomyces cerevisiae have pinpointed the biomolecules that oxidants can damage and the strategies by which microbes minimize their injuries. What is lacking is a good sense of the circumstances under which oxidative stress actually occurs. In this MiniReview several potential natural sources of oxidative stress are considered: endogenous ROS formation, chemical oxidation of reduced species at oxic-anoxic interfaces, H O production by lactic acid bacteria, the oxidative burst of phagocytes and the redox-cycling of secreted small molecules. While all of these phenomena can be reproduced and verified in the lab, the actual quantification of stress in natural habitats remains lacking - and, therefore, we have a fundamental hole in our understanding of the role that oxidative stress actually plays in the biosphere.
Topics: Bacteria; Hydrogen Peroxide; Oxidants; Oxidation-Reduction; Oxidative Stress; Superoxides
PubMed: 30307099
DOI: 10.1111/1462-2920.14445 -
Molecular Cell Jan 2018Some of the most challenging stress conditions that organisms encounter during their lifetime involve the transient accumulation of reactive oxygen and chlorine species.... (Review)
Review
Some of the most challenging stress conditions that organisms encounter during their lifetime involve the transient accumulation of reactive oxygen and chlorine species. Extremely reactive to amino acid side chains, these oxidants cause widespread protein unfolding and aggregation. It is therefore not surprising that cells draw on a variety of different strategies to counteract the damage and maintain a healthy proteome. Orchestrated largely by direct changes in the thiol oxidation status of key proteins, the response strategies involve all layers of protein protection. Reprogramming of basic biological functions helps decrease nascent protein synthesis and restore redox homeostasis. Mobilization of oxidative stress-activated chaperones and production of stress-resistant non-proteinaceous chaperones prevent irreversible protein aggregation. Finally, redox-controlled increase in proteasome activity removes any irreversibly damaged proteins. Together, these systems pave the way to restore protein homeostasis and enable organisms to survive stress conditions that are inevitable when living an aerobic lifestyle.
Topics: Animals; Heat-Shock Proteins; Humans; Molecular Chaperones; Oxidants; Oxidation-Reduction; Oxidative Stress; Protein Unfolding; Proteome; Proteostasis; Reactive Oxygen Species; Sulfhydryl Compounds
PubMed: 29351842
DOI: 10.1016/j.molcel.2017.12.021 -
Annals of the American Thoracic Society Mar 2016Research over the past 30 years has identified mechanistic biochemical oxidation pathways that contribute to asthma pathophysiology. Redox imbalance is present in asthma... (Review)
Review
Research over the past 30 years has identified mechanistic biochemical oxidation pathways that contribute to asthma pathophysiology. Redox imbalance is present in asthma and strongly linked to the pathobiology of airflow obstruction, airway hyperreactivity, and remodeling. High levels of reactive oxygen species, reactive nitrogen species, and oxidatively modified proteins in the lung, blood, and urine provide conclusive evidence for pathologic oxidation in asthma. Concurrent loss of antioxidants, such as superoxide dismutases and catalase, is attributed to redox modifications of the enzymes, and further amplifies the oxidative injury in the airway. The presence of high levels of urine bromotyrosine, an oxidation product of eosinophil peroxidase, identifies activated eosinophils, and shows promise for use as a noninvasive biomarker of poor asthma control.
Topics: Asthma; Humans; Lung; Oxidants; Oxidation-Reduction; Oxidative Stress; Reactive Nitrogen Species; Reactive Oxygen Species
PubMed: 27027950
DOI: 10.1513/AnnalsATS.201506-385MG