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Progress in Lipid Research Apr 2024Lipid oxidation constitutes the main source of degradation of lipid-rich foods, including food emulsions. The complexity of the reactions at play combined with the... (Review)
Review
Lipid oxidation constitutes the main source of degradation of lipid-rich foods, including food emulsions. The complexity of the reactions at play combined with the increased demand from consumers for less processed and more natural foods result in additional challenges in controlling this phenomenon. This review provides an overview of the insights acquired over the past two decades on the understanding of lipid oxidation in oil-in-water (O/W) emulsions. After introducing the general structure of O/W emulsions and the classical mechanisms of lipid oxidation, the contribution of less studied oxidation products and the spatiotemporal resolution of these reactions will be discussed. We then highlight the impact of emulsion formulation on the mechanisms, taking into consideration the new trends in terms of emulsifiers as well as their own sensitivity to oxidation. Finally, novel antioxidant strategies that have emerged to meet the recent consumer's demand will be detailed. In an era defined by the pursuit of healthier, more natural, and sustainable food choices, a comprehensive understanding of lipid oxidation in emulsions is not only an academic quest, but also a crucial step towards meeting the evolving expectations of consumers and ensuring the quality and stability of lipid-rich food products.
Topics: Emulsions; Oxidation-Reduction; Humans; Lipids; Antioxidants; Lipid Metabolism
PubMed: 38280491
DOI: 10.1016/j.plipres.2024.101275 -
Microbial Biotechnology Nov 2023The global economic burden of microbial corrosion of metals is enormous. Microbial corrosion of iron-containing metals is most extensive under anaerobic conditions.... (Review)
Review
The global economic burden of microbial corrosion of metals is enormous. Microbial corrosion of iron-containing metals is most extensive under anaerobic conditions. Microbes form biofilms on metal surfaces and can directly extract electrons derived from the oxidation of Fe to Fe to support anaerobic respiration. H generated from abiotic Fe oxidation also serves as an electron donor for anaerobic respiratory microbes. Microbial metabolites accelerate this abiotic Fe oxidation. Traditional strategies for curbing microbial metal corrosion include cathodic protection, scrapping, a diversity of biocides, alloys that form protective layers or release toxic metal ions, and polymer coatings. However, these approaches are typically expensive and/or of limited applicability and not environmentally friendly. Biotechnology may provide more effective and sustainable solutions. Biocides produced with microbes can be less toxic to eukaryotes, expanding the environments for potential application. Microbially produced surfactants can diminish biofilm formation by corrosive microbes, as can quorum-sensing inhibitors. Amendments of phages or predatory bacteria have been successful in attacking corrosive microbes in laboratory studies. Poorly corrosive microbes can form biofilms and/or deposit extracellular polysaccharides and minerals that protect the metal surface from corrosive microbes and their metabolites. Nitrate amendments permit nitrate reducers to outcompete highly corrosive sulphate-reducing microbes, reducing corrosion. Investigation of all these more sustainable corrosion mitigation strategies is in its infancy. More study, especially under environmentally relevant conditions, including diverse microbial communities, is warranted.
Topics: Humans; Nitrates; Corrosion; Caustics; Metals; Oxidation-Reduction; Biofilms; Disinfectants
PubMed: 37796110
DOI: 10.1111/1751-7915.14347 -
Biomacromolecules Dec 2023Hydrogels of cellulose nanofibrils (CNFs) are promising wound dressing candidates due to their biocompatibility, high water absorption, and transparency. Herein, two...
Hydrogels of cellulose nanofibrils (CNFs) are promising wound dressing candidates due to their biocompatibility, high water absorption, and transparency. Herein, two different commercially available wood species, softwood and hardwood, were subjected to TEMPO-mediated oxidation to proceed with delignification and oxidation in a one-pot process, and thereafter, nanofibrils were isolated using a high-pressure microfluidizer. Furthermore, transparent nanofibril hydrogel networks were prepared by vacuum filtration. Nanofibril properties and network performance correlated with oxidation were investigated and compared with commercially available TEMPO-oxidized pulp nanofibrils and their networks. Softwood nanofibril hydrogel networks exhibited the best mechanical properties, and toxicological risk assessment showed no detrimental effect for any of the studied hydrogels on human fibroblast or keratinocyte cells. This study demonstrates a straightforward processing route for direct oxidation of different wood species to obtain nanofibril hydrogels for potential use as wound dressings, with softwood having the most potential.
Topics: Humans; Hydrogels; Cellulose; Bandages; Oxidation-Reduction; Fibroblasts
PubMed: 37950687
DOI: 10.1021/acs.biomac.3c00596 -
Environmental Science & Technology Jul 2023Structural Fe in clay minerals is an important, potentially renewable source of electron equivalents for contaminant reduction, yet our knowledge of how clay mineral Fe...
Structural Fe in clay minerals is an important, potentially renewable source of electron equivalents for contaminant reduction, yet our knowledge of how clay mineral Fe reduction pathways and Fe reduction extent affect clay mineral Fe(II) reactivity is limited. Here, we used a nitroaromatic compound (NAC) as a reactive probe molecule to assess the reactivity of chemically reduced (dithionite) and Fe(II)-reduced nontronite across a range of reduction extents. We observed biphasic transformation kinetics for all nontronite reduction extents of ≥5% Fe(II)/Fe(total) regardless of the reduction pathway, indicating that two Fe(II) sites of different reactivities form in nontronite at environmentally relevant reduction extents. At even lower reduction extents, Fe(II)-reduced nontronite completely reduced the NAC whereas dithionite-reduced nontronite could not. Our Fe Mössbauer spectroscopy, ultraviolet-visible spectroscopy, and kinetic modeling results suggest that the highly reactive Fe(II) entities likely comprise di/trioctahedral Fe(II) domains in the nontronite structure regardless of the reduction mechanism. However, the second Fe(II) species, of lower reactivity, varies and for Fe(II)-reacted NAu-1 likely comprises Fe(II) associated with an Fe-bearing precipitate formed during electron transfer from aqueous to nontronite Fe. Both our observation of biphasic reduction kinetics and the nonlinear relationship of rate constant and clay mineral reduction potential have major implications for contaminant fate and remediation.
Topics: Clay; Dithionite; Oxidation-Reduction; Minerals; Ferrous Compounds; Ferric Compounds
PubMed: 37418593
DOI: 10.1021/acs.est.3c01655 -
Nature Communications Dec 2023Precise coupling between cellular physiology and metabolism is emerging as a vital relationship underpinning tissue health and longevity. Nevertheless,...
Precise coupling between cellular physiology and metabolism is emerging as a vital relationship underpinning tissue health and longevity. Nevertheless, functional-metabolic coupling within heterogenous microenvironments in vivo remains poorly understood due to tissue complexity and metabolic plasticity. Here, we establish the Drosophila renal system as a paradigm for linking mechanistic analysis of metabolism, at single-cell resolution, to organ-wide physiology. Kidneys are amongst the most energetically-demanding organs, yet exactly how individual cell types fine-tune metabolism to meet their diverse, unique physiologies over the life-course remains unclear. Integrating live-imaging of metabolite and organelle dynamics with spatio-temporal genetic perturbation within intact functional tissue, we uncover distinct cellular metabolic signatures essential to support renal physiology and healthy ageing. Cell type-specific programming of glucose handling, PPP-mediated glutathione regeneration and FA β-oxidation via dynamic lipid-peroxisomal networks, downstream of differential ERR receptor activity, precisely match cellular energetic demands whilst limiting damage and premature senescence; however, their dramatic dysregulation may underlie age-related renal dysfunction.
Topics: Humans; Kidney; Mitochondria; Oxidation-Reduction; Longevity; Aging, Premature
PubMed: 38110414
DOI: 10.1038/s41467-023-44098-x -
Nature Communications Oct 2023Sulfate-reducing microorganisms represent a globally important link between the sulfur and carbon cycles. Recent metagenomic surveys expanded the diversity of...
Sulfate-reducing microorganisms represent a globally important link between the sulfur and carbon cycles. Recent metagenomic surveys expanded the diversity of microorganisms putatively involved in sulfate reduction underscoring our incomplete understanding of this functional guild. Here, we use genome-centric metatranscriptomics to study the energy metabolism of Acidobacteriota that carry genes for dissimilation of sulfur compounds in a long-term continuous culture running under alternating anoxic and oxic conditions. Differential gene expression analysis reveals the unique metabolic flexibility of a pectin-degrading acidobacterium to switch from sulfate to oxygen reduction when shifting from anoxic to oxic conditions. The combination of facultative anaerobiosis and polysaccharide degradation expands the metabolic versatility among sulfate-reducing microorganisms. Our results highlight that sulfate reduction and aerobic respiration are not mutually exclusive in the same organism, sulfate reducers can mineralize organic polymers, and anaerobic mineralization of complex organic matter is not necessarily a multi-step process involving different microbial guilds but can be bypassed by a single microbial species.
Topics: Sulfates; Oxygen; Anaerobiosis; Acidobacteria; Respiration; Polysaccharides; Oxidation-Reduction
PubMed: 37816749
DOI: 10.1038/s41467-023-42074-z -
Frontiers in Immunology 2023Although macrophages are known to be affected by their redox status, oxidation is not yet a well-recognized post-translational modification (PTM) in regulating...
Although macrophages are known to be affected by their redox status, oxidation is not yet a well-recognized post-translational modification (PTM) in regulating macrophages and immune cells in general. While it has been described that the redox status of single cysteines in specific proteins is relevant for macrophage functions, global oxidation information is scarce. Hence, we globally assessed the impact of oxidation on macrophage activation using untargeted proteomics and PTM-omics. We exposed THP-1 macrophages to lipopolysaccharide (LPS) for 4 h and 24 h and applied a sequential iodoTMT labeling approach to get information on overall oxidation as well as reversible oxidation of cysteines. Thus, we identified 10452 oxidation sites, which were integratively analyzed with 5057 proteins and 7148 phosphorylation sites to investigate their co-occurance with other omics layers. Based on this integrative analysis, we found significant upregulation of several immune-related pathways, e.g. toll-like receptor 4 (TLR4) signaling, for which 19 proteins, 7 phosphorylation sites, and 39 oxidation sites were significantly affected, highlighting the relevance of oxidations in TLR4-induced macrophage activation. Co-regulation of oxidation and phosphorylation was observed, as evidenced by multiply modified proteins related to inflammatory pathways. Additionally, we observed time-dependent effects, with differences in the dynamics of oxidation sites compared to proteins and phosphorylation sites. Overall, this study highlights the importance of oxidation in regulating inflammatory processes and provides a method that can be readily applied to study the cellular redoxome globally.
Topics: Phosphorylation; Toll-Like Receptor 4; Protein Processing, Post-Translational; Immunity; Oxidation-Reduction
PubMed: 37809076
DOI: 10.3389/fimmu.2023.1244431 -
Redox Biology Apr 2024A multitude of cellular metabolic and regulatory processes rely on controlled thiol reduction and oxidation mechanisms. Due to our aerobic environment, research...
A multitude of cellular metabolic and regulatory processes rely on controlled thiol reduction and oxidation mechanisms. Due to our aerobic environment, research preferentially focuses on oxidation processes, leading to limited tools tailored for investigating cellular reduction. Here, we advocate for repurposing HyPer1, initially designed as a fluorescent probe for HO levels, as a tool to measure the reductive power in various cellular compartments. The response of HyPer1 depends on kinetics between thiol oxidation and reduction in its OxyR sensing domain. Here, we focused on the reduction half-reaction of HyPer1. We showed that HyPer1 primarily relies on Trx/TrxR-mediated reduction in the cytosol and nucleus, characterized by a second order rate constant of 5.8 × 10 Ms. On the other hand, within the mitochondria, HyPer1 is predominantly reduced by glutathione (GSH). The GSH-mediated reduction rate constant is 1.8 Ms. Using human leukemia K-562 cells after a brief oxidative exposure, we quantified the compartmentalized Trx/TrxR and GSH-dependent reductive activity using HyPer1. Notably, the recovery period for mitochondrial HyPer1 was twice as long compared to cytosolic and nuclear HyPer1. After exploring various human cells, we revealed a potent cytosolic Trx/TrxR pathway, particularly pronounced in cancer cell lines such as K-562 and HeLa. In conclusion, our study demonstrates that HyPer1 can be harnessed as a robust tool for assessing compartmentalized reduction activity in cells following oxidative stress.
Topics: Humans; Hydrogen Peroxide; Thioredoxin-Disulfide Reductase; Oxidation-Reduction; Glutathione; Cell Line, Tumor; Sulfhydryl Compounds; Thioredoxins
PubMed: 38310683
DOI: 10.1016/j.redox.2024.103058 -
International Journal of Molecular... Jan 2024Nitroxides are stable free radicals that have antioxidant properties. They react with many types of radicals, including alkyl and peroxyl radicals. They act as mimics of... (Review)
Review
Nitroxides are stable free radicals that have antioxidant properties. They react with many types of radicals, including alkyl and peroxyl radicals. They act as mimics of superoxide dismutase and stimulate the catalase activity of hemoproteins. In some situations, they may exhibit pro-oxidant activity, mainly due to the formation of oxoammonium cations as products of their oxidation. In this review, the cellular effects of nitroxides and their effects in animal experiments and clinical trials are discussed, including the beneficial effects in various pathological situations involving oxidative stress, protective effects against UV and ionizing radiation, and prolongation of the life span of cancer-prone mice. Nitroxides were used as active components of various types of nanoparticles. The application of these nanoparticles in cellular and animal experiments is also discussed.
Topics: Mice; Animals; Antioxidants; Oxidation-Reduction; Free Radicals; Oxidative Stress; Nitrogen Oxides; Cyclic N-Oxides
PubMed: 38338725
DOI: 10.3390/ijms25031446 -
Biomedicine & Pharmacotherapy =... Sep 2023Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological... (Review)
Review
Redox homeostasis refers to the dynamic equilibrium between oxidant and reducing agent in the body which plays a crucial role in maintaining normal physiological activities of the body. The imbalance of redox homeostasis can lead to the development of various human diseases. Lysosomes regulate the degradation of cellular proteins and play an important role in influencing cell function and fate, and lysosomal dysfunction is closely associated with the development of various diseases. In addition, several studies have shown that redox homeostasis plays a direct or indirect role in regulating lysosomes. Therefore, this paper systematically reviews the role and mechanisms of redox homeostasis in the regulation of lysosomal function. Therapeutic strategies based on the regulation of redox exerted to disrupt or restore lysosomal function are further discussed. Uncovering the role of redox in the regulation of lysosomes helps to point new directions for the treatment of many human diseases.
Topics: Humans; Homeostasis; Oxidation-Reduction; Lysosomes; Autophagy
PubMed: 37418979
DOI: 10.1016/j.biopha.2023.115121