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The Science of the Total Environment Oct 2021In recent years, there has been increasing interest in using of advanced oxidation processes in water and wastewater decontamination. As a new oxidants peracids, mainly... (Review)
Review
Peracids - New oxidants in advanced oxidation processes: The use of peracetic acid, peroxymonosulfate, and persulfate salts in the removal of organic micropollutants of emerging concern - A review.
In recent years, there has been increasing interest in using of advanced oxidation processes in water and wastewater decontamination. As a new oxidants peracids, mainly peracetic acid (PAA) and peracid salts, i.e. peroxymonosulfate (PMS) and persulfate (PS) are used. The degradation process of organic compounds takes place with the participation of radicals, including hydroxyl (OH) and sulfate (SO) radicals derived from the peracids activation processes. Peracids can be activated in homogeneous systems (UV radiation, d-electron metal ions, e.g. Fe, Co, Mn, base, ozonolysis, thermolysis, radiolysis), or using heterogeneous activation (metals with zero oxidation state, metal oxides, quinones, activated carbon, semiconductors). As a result of oxidation, products of a lower mass than the parent compounds, less toxic, and more susceptible to biodegradation are formed. An important task is to investigate the effect of the peracid activation method and matrix composition on the efficiency of contamination removal. The article presents the latest information about the application of peracids in the removal of organic micropollutants of emerging concern (mainly focuses on endocrine disrupted compounds). The most important information on peracetic acid, peroxymonosulfate and persulfate salts, and methods of their activation are presented. Current uses of these oxidants in organic micropollutants removal are also described. Information was collected on the factors influencing the oxidation process and the effectiveness of pollutant removal. This paper compares PAA, PMS and PS-based processes for the first time in terms of kinetics and efficiency.
Topics: Oxidants; Oxidation-Reduction; Peracetic Acid; Peroxides; Salts; Water Pollutants, Chemical
PubMed: 34380254
DOI: 10.1016/j.scitotenv.2021.148195 -
The Journal of Physiology Jun 2021LRRC8A-containing anion channels associate with NADPH oxidase 1 (Nox1) and regulate superoxide production and tumour necrosis factor-α (TNFα) signalling. Here we show...
KEY POINTS
LRRC8A-containing anion channels associate with NADPH oxidase 1 (Nox1) and regulate superoxide production and tumour necrosis factor-α (TNFα) signalling. Here we show that LRRC8C and 8D also co-immunoprecipitate with Nox1 in vascular smooth muscle cells. LRRC8C knockdown inhibited TNFα-induced O production, receptor endocytosis, nuclear factor-κB (NF-κB) activation and proliferation while LRRC8D knockdown enhanced NF-κB activation. Significant changes in LRRC8 isoform expression in human atherosclerosis and psoriasis suggest compensation for increased inflammation. The oxidant chloramine-T (ChlorT, 1 mM) weakly (∼25%) inhibited LRRC8C currents but potently (∼80%) inhibited LRRC8D currents. Substitution of the extracellular loop (EL1, EL2) domains of 8D into 8C conferred significantly stronger (69%) ChlorT-dependent inhibition. ChlorT exposure impaired subsequent current block by DCPIB, which occurs through interaction with EL1, further implicating external oxidation sites. LRRC8A/C channels most effectively sustain Nox1 activity at the plasma membrane. This may result from their ability to remain active in an oxidized microenvironment.
ABSTRACT
Tumour necrosis factor-α (TNFα) activates NADPH oxidase 1 (Nox1) in vascular smooth muscle cells (VSMCs), producing superoxide (O ) required for subsequent signalling. LRRC8 family proteins A-E comprise volume-regulated anion channels (VRACs). The required subunit LRRC8A physically associates with Nox1, and VRAC activity is required for Nox activity and the inflammatory response to TNFα. VRAC currents are modulated by oxidants, suggesting that channel oxidant sensitivity and proximity to Nox1 may play a physiologically relevant role. In VSMCs, LRRC8C knockdown (siRNA) recapitulated the effects of siLRRC8A, inhibiting TNFα-induced extracellular and endosomal O production, receptor endocytosis, nuclear factor-κB (NF-κB) activation and proliferation. In contrast, siLRRC8D potentiated NF-κB activation. Nox1 co-immunoprecipitated with 8C and 8D, and colocalized with 8D at the plasma membrane and in vesicles. We compared VRAC currents mediated by homomeric and heteromeric LRRC8C and LRRC8D channels expressed in HEK293 cells. The oxidant chloramine T (ChlorT, 1 mM) weakly inhibited 8C, but potently inhibited 8D currents. ChlorT exposure also impaired subsequent current block by the VRAC blocker DCPIB, implicating external sites of oxidation. Substitution of the 8D extracellular loop domains (EL1, EL2) into 8C conferred significantly stronger ChlorT-mediated inhibition of 8C currents. Our results suggest that LRRC8A/C channel activity can be effectively maintained in the oxidized microenvironment expected to result from Nox1 activation at the plasma membrane. Increased ratios of 8D:8C expression may potentially depress inflammatory responses to TNFα. LRRC8A/C channel downregulation represents a novel strategy to reduce TNFα-induced inflammation.
Topics: Anions; HEK293 Cells; Humans; Membrane Proteins; NADPH Oxidase 1; Oxidants; Superoxides
PubMed: 33932953
DOI: 10.1113/JP281577 -
IUBMB Life Oct 2006In this review we have analyzed the reactions of nitric oxide (.NO) with superoxide radical (O(2).-) at the vascular compartment which results in limitation of the... (Review)
Review
In this review we have analyzed the reactions of nitric oxide (.NO) with superoxide radical (O(2).-) at the vascular compartment which results in limitation of the bioavailability of .NO and the formation of peroxynitrite (ONOO-), a strong oxidant species. The intravascular formation of peroxynitrite can result in oxidative modifications of plasma and vessel wall proteins including the formation of protein-3-nitrotyrosine. The role of red blood cells (RBC) and oxyhemoglobin in the metabolism of intravascular peroxynitrite will be discussed. While RBC constitute an important 'sink' of both .NO and peroxynitrite, redox reactions of these species with oxyhemoglobin may in part contribute to erythrocyte aging. The intravascular formation, reactions and detoxification of peroxynitrite are revealed as important factors controlling vascular dysfunction and degeneration in a variety of pathophysiologically-relevant conditions.
Topics: Blood Vessels; Erythrocytes; Humans; Molecular Structure; Nitric Oxide; Oxidants; Peroxynitrous Acid; Signal Transduction; Superoxides; Tyrosine
PubMed: 17050374
DOI: 10.1080/15216540600936549 -
Nitric Oxide : Biology and Chemistry Aug 2011
Topics: Humans; Nitric Oxide; Oxidants; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species; Signal Transduction
PubMed: 21596152
DOI: 10.1016/j.niox.2011.05.002 -
Biology Open Apr 2023One challenge for invading pathogens represents the exposure to highly microbicidal hypohalous acids (HOX), such as hypochlorous acid (HOCl) and hypothiocyanous acid...
One challenge for invading pathogens represents the exposure to highly microbicidal hypohalous acids (HOX), such as hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN). Generated at high concentrations by innate immune cells during phagocytosis, HOX kills the engulfed microbes through extensive macromolecular damage. However, microorganisms have evolved strategies to detoxify the oxidants and/or alleviate HOX-mediated damage, which improves their survival during HOX exposure. Many of these defense systems are bacteria-specific and therefore considered potential drug targets. Our minireview highlights recent (July 2021 to November 2022) advances in the field of microbial HOX defense systems and how these systems are regulated. We report recent progress on redox-sensing transcriptional regulators, two-component systems, and σ/anti-σ factors and review how oxidative modifications in these regulatory proteins affect the expression of their target genes. Moreover, we discuss novel studies that describe how HOCl affects the activity of redox-regulated enzymes and highlight mechanisms that bacteria employ to reduce HOSCN.
Topics: Oxidants; Hypochlorous Acid; Oxidation-Reduction; Bacteria
PubMed: 37102360
DOI: 10.1242/bio.059809 -
Molecules (Basel, Switzerland) Feb 2020The development of sustainable processes and products through innovative catalytic materials and procedures that allow a better use of resources is undoubtedly one of... (Review)
Review
The development of sustainable processes and products through innovative catalytic materials and procedures that allow a better use of resources is undoubtedly one of the most significant issues facing researchers nowadays. Environmental and economically advanced catalytic processes for selective oxidation of alcohols are currently focused on designing new catalysts able to activate green oxidants (dioxygen or peroxides) and applying unconventional conditions of sustainable significance, like the use of microwave irradiation as an alternative energy source. This short review aims to provide an overview of the recently (2015-2020) discovered homogeneous aerobic and peroxidative oxidations of primary and secondary alcohols catalyzed by copper complexes, highlighting new catalysts with potential application in sustainable organic synthesis, with significance in academia and industry.
Topics: Alcohols; Catalysis; Copper; Green Chemistry Technology; Humans; Microwaves; Molecular Structure; Oxidants; Oxidation-Reduction; Oxygen; Peroxides
PubMed: 32050493
DOI: 10.3390/molecules25030748 -
IUBMB Life 2000The production of hypochlorous acid (HOCl) by the myeloperoxidase-H2O2-Cl- system of phagocytes plays a vital role in the ability of these cells to kill a wide range of... (Review)
Review
The production of hypochlorous acid (HOCl) by the myeloperoxidase-H2O2-Cl- system of phagocytes plays a vital role in the ability of these cells to kill a wide range of pathogens. However, the generation of a potent oxidant is not without risk to the host, and there is evidence that HOCl contributes to the tissue injury associated with inflammation. In this review, we discuss the biological reactivity of HOCl, and detail what is known of how it interacts with mammalian cells. The outcome of exposure is dependent on the dose of oxidant, with higher doses causing necrosis, and apoptosis or growth arrest occurring with lower amounts. Glutathione (GSH) and protein thiols are easily oxidized, and are preferred targets with low, sublethal amounts of HOCl. Thiol enzymes vary in their sensitivity to HOCl, with glyceraldehyde-3-phosphate dehydrogenase being most susceptible. Indeed, loss of activity occurred before GSH oxidation. The products of these reactions and the ability of cells to regenerate oxidized thiols are discussed. Recent reports have indicated that HOCl can activate cell signaling pathways, and these studies may provide important information on the role of this oxidant in inflammation.
Topics: Animals; Apoptosis; Cell Survival; Glutathione; Humans; Hypochlorous Acid; Necrosis; Oxidants; Oxidative Stress; Proteins; Signal Transduction
PubMed: 11327319
DOI: 10.1080/713803731 -
Cells Nov 2021Chronic airway inflammation and oxidative stress play crucial roles in the pathogenesis of chronic inflammatory lung diseases, with airway inflammation being a key...
Chronic airway inflammation and oxidative stress play crucial roles in the pathogenesis of chronic inflammatory lung diseases, with airway inflammation being a key driving mechanism of oxidative stress in the lungs. Inflammatory responses in the lungs activate neutrophils and/or eosinophils, leading to the generation of hypohalous acids (HOX). These HOX oxidants can damage the extracellular matrix (ECM) structure and may influence cell-ECM interactions. The ECM of the lung provides structural, mechanical, and biochemical support for cells and determines the airway structure. One of the critical cells in chronic respiratory disease is the fibroblast. Thus, we hypothesised that primary human lung fibroblasts (PHLF) exposed to an oxidised cell-derived ECM will result in functional changes to the PHLF. Here, we show that PHLF adhesion, proliferation, and inflammatory cytokine secretion is affected by exposure to HOX-induced oxidisation of the cell-derived ECM. Furthermore, we investigated the impact on fibroblast function from the presence of haloamines in the ECM. Haloamines are chemical by-products of HOX and, like the HOX, haloamines can also modify the ECM. In conclusion, this study revealed that oxidising the cell-derived ECM might contribute to functional changes in PHLF, a key mechanism behind the pathogenesis of inflammatory lung diseases.
Topics: Bromates; Cell Adhesion; Cell Proliferation; Cell Shape; Collagen Type I; Cytokines; Extracellular Matrix; Fibroblasts; Granulocytes; Humans; Hypochlorous Acid; Inflammation Mediators; Lung; Middle Aged; Oxidants; Oxidation-Reduction
PubMed: 34943857
DOI: 10.3390/cells10123351 -
Oxidant-redox regulation of pulmonary vascular responses to hypoxia and nitric oxide-cGMP signaling.Cardiology in Review 2010Most current theories for the mechanism of hypoxic pulmonary vasoconstriction (HPV) include a role for reactive oxygen species and/or changes in redox regulation, but... (Review)
Review
Most current theories for the mechanism of hypoxic pulmonary vasoconstriction (HPV) include a role for reactive oxygen species and/or changes in redox regulation, but extreme controversy exists regarding which systems and redox changes mediate the HPV response. Nitric oxide (NO) appears to help to maintain low pulmonary arterial pressure, suppress HPV, and prevent the development of pulmonary hypertension. Our studies have found a key role for glucose-6-phosphate dehydrogenase in bovine pulmonary arterial smooth muscle functioning to maintain elevated levels of cytosolic NADPH which fuels the generation of vasodilator levels of hydrogen peroxide. HPV results from hypoxia removing vasodilation by peroxide. Decreased superoxide generation by Nox4 oxidase and its conversion to peroxide by Cu,Zn-SOD appear to be potential factors in sensing hypoxia, and decreased cGMP-associated vasodilation and removal of redox controlled vasodilator mechanisms by increased cytosolic NADPH may be key coordinators of the HPV response. Oxidant generation associated with vascular disease processes, including the removal of NO by superoxide, and attenuation of its ability to stimulate cGMP production by oxidation of the heme and thiols of soluble guanylate cyclase attenuate potential beneficial actions of NO on pulmonary arterial function. While pulmonary hypertension appears to have multiple poorly understood effects on redox-associated processes, potentially influencing responses to hypoxia and NO-cGMP signaling, much remains to be elucidated regarding how these processes may be important factors in the progression, expression and therapeutic treatment of pulmonary hypertension.
Topics: Animals; Cyclic GMP; Cytosol; Disease Progression; Glucosephosphate Dehydrogenase; Humans; Hydrogen Peroxide; Hypertension, Pulmonary; Hypoxia; NADP; Nitric Oxide; Oxidants; Oxidation-Reduction; Pulmonary Artery; Reactive Oxygen Species; Signal Transduction; Vasoconstriction; Vasodilation
PubMed: 20160535
DOI: 10.1097/CRD.0b013e3181c9f088 -
International Journal of Environmental... Mar 2023NO is a greenhouse gas and a candidate oxidant. Volatile organic pollutants (VOCs) have caused great harm to the atmospheric ecological environment. Developing the...
NO is a greenhouse gas and a candidate oxidant. Volatile organic pollutants (VOCs) have caused great harm to the atmospheric ecological environment. Developing the technique utilizing NO as the oxidant to oxidize VOCs to realize the collaborative purification has significant importance and practical value for NO emission control and VOC abatement. Therefore, the study of NO catalytic oxidation of tert-butanol based on zeolite catalysts was carried out. A series of molecular sieves, including FER, MOR, ZSM-5, Y, and BEA, were selected as the catalyst objects, and the 1.5% wt Fe and Co were, respectively, loaded on the zeolite catalysts via the impregnation method. It was found that the catalytic performance of BEA was the best among the molecular sieves. Comparing the catalytic performance of Fe-BEA under different load gradients (0.25~2%), it was found that 1.5% Fe-BEA possessed the best catalytic activity. A series of characterization methods showed that Fe content in 1.5% Fe-BEA was the highest, and more active sites formed to promote the catalytic reaction. The α-O in the reaction eventually oxidized tert-butanol to CO over the active site. The Co mainly existed in the form of Co cations over Co-BEA samples; the 2% Co-BEA possessing higher amounts of Co exhibited the highest activity among the prepared Co-BEA samples.
Topics: tert-Butyl Alcohol; Zeolites; Oxidants; Oxidation-Reduction
PubMed: 36981811
DOI: 10.3390/ijerph20064902