407 results on '"redox biology"'
Search Results
102. New Challenges to Study Heterogeneity in Cancer Redox Metabolism
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Rui Benfeitas, Mathias Uhlen, Jens Nielsen, and Adil Mardinoglu
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cancer heterogeneity ,redox biology ,reactive oxygen species ,systems biology ,personalized medicine ,Biology (General) ,QH301-705.5 - Abstract
Reactive oxygen species (ROS) are important pathophysiological molecules involved in vital cellular processes. They are extremely harmful at high concentrations because they promote the generation of radicals and the oxidation of lipids, proteins, and nucleic acids, which can result in apoptosis. An imbalance of ROS and a disturbance of redox homeostasis are now recognized as a hallmark of complex diseases. Considering that ROS levels are significantly increased in cancer cells due to mitochondrial dysfunction, ROS metabolism has been targeted for the development of efficient treatment strategies, and antioxidants are used as potential chemotherapeutic drugs. However, initial ROS-focused clinical trials in which antioxidants were supplemented to patients provided inconsistent results, i.e., improved treatment or increased malignancy. These different outcomes may result from the highly heterogeneous redox responses of tumors in different patients. Hence, population-based treatment strategies are unsuitable and patient-tailored therapeutic approaches are required for the effective treatment of patients. Moreover, due to the crosstalk between ROS, reducing equivalents [e.g., NAD(P)H] and central metabolism, which is heterogeneous in cancer, finding the best therapeutic target requires the consideration of system-wide approaches that are capable of capturing the complex alterations observed in all of the associated pathways. Systems biology and engineering approaches may be employed to overcome these challenges, together with tools developed in personalized medicine. However, ROS- and redox-based therapies have yet to be addressed by these methodologies in the context of disease treatment. Here, we review the role of ROS and their coupled redox partners in tumorigenesis. Specifically, we highlight some of the challenges in understanding the role of hydrogen peroxide (H2O2), one of the most important ROS in pathophysiology in the progression of cancer. We also discuss its interplay with antioxidant defenses, such as the coupled peroxiredoxin/thioredoxin and glutathione/glutathione peroxidase systems, and its reducing equivalent metabolism. Finally, we highlight the need for system-level and patient-tailored approaches to clarify the roles of these systems and identify therapeutic targets through the use of the tools developed in personalized medicine.
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- 2017
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103. Reductive stress after exercise: The issue of redox individuality
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N.V. Margaritelis, A. Kyparos, V. Paschalis, A.A. Theodorou, G. Panayiotou, A. Zafeiridis, K. Dipla, M.G. Nikolaidis, and I.S. Vrabas
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Antioxidants ,Free radicals ,Individuality ,Muscle damage ,Oxidative stress ,Redox biology ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Exercise has been consistently used as an oxidant stimulus in redox biology studies. However, previous studies have focused on group differences and did not examine individual differences. As a result, it remains untested whether all individuals experience oxidative stress after acute exercise. Therefore, the main aim of the present study was to investigate whether some individuals exhibit unexpected responses after an acute eccentric (i.e., muscle-damaging) exercise session. Ninety eight (N = 98) young men performed an isokinetic eccentric exercise bout with the knee extensors. Plasma, erythrocytes and urine samples were collected immediately before and 2 days post-exercise. Three commonly used redox biomarkers (F2-isoprostanes, protein carbonyls and glutathione) were assayed. As expected, the two oxidant biomarkers (F2-isoprostanes and protein carbonyls) significantly increased 2 days after exercise (46% and 61%, respectively); whereas a significant decrease in glutathione levels (by −21%) was observed after exercise. A considerable number of the participants exhibited changes in the levels of biomarkers in the opposite, unexpected direction than the group average. More specifically, 13% of the participants exhibited a decrease in F2-isoprostanes and protein carbonyls and 10% of the participants exhibited an increase in glutathione levels. Furthermore, more than 1 out of 3 individuals exhibited either unexpected or negligible (from 0% to ± 5%) responses to exercise in at least one redox biomarker. It was also observed that the initial values of redox biomarkers are important predictors of the responses to exercise. In conclusion, although exercise induces oxidative stress in the majority of individuals, it can induce reductive stress or negligible stress in a considerable number of people. The data presented herein emphasize that the mean response to a redox stimulus can be very misleading. We believe that the wide variability (including the cases of reductive stress) described is not limited to the oxidant stimulus used and the biomarkers selected.
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- 2014
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104. Platelet-derived extracellular vesicles express NADPH oxidase-1 (Nox-1), generate superoxide and modulate platelet function
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Joanne L. Mitchell, Jonathan M. Gibbins, Giordano Pula, Renato Simões Gaspar, and Plinio Ferreira
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Blood Platelets ,Platelets ,0301 basic medicine ,Short Communication ,CRP, collagen-related peptide ,ERK, extracellular signal-regulated kinases ,GAPDH, glyceraldehyde 3-phosphate dehydrogenase ,NADPH Oxidase ,Biochemistry ,Collagen receptor ,PRP, platelet-rich plasma ,Extracellular Vesicles ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,NTA, nanoparticle tracking analysis ,PMA, phorbol-12-myristate-13-acetate ,Superoxides ,Physiology (medical) ,PKC, protein kinase C ,EV, extracellular vesicles ,TRAP-6, thrombin receptor activator peptide 6 ,Platelet ,Platelet activation ,Redox biology ,chemistry.chemical_classification ,Reactive oxygen species ,NADPH oxidase ,biology ,Chemistry ,Superoxide ,NADPH Oxidases ,Fibrinogen binding ,NADPH, nicotinamide adenine dinucleotide phosphate ,Platelet Activation ,Cell biology ,WP, washed platelets ,030104 developmental biology ,GPVI, Glycoprotein VI ,PDEVs, platelet-derived extracellular vesicles ,NADPH Oxidase 1 ,biology.protein ,GPVI ,Reactive Oxygen Species ,030217 neurology & neurosurgery - Abstract
Background Platelets release platelet-derived extracellular vesicles (PDEVs) upon activation – in a process that is regulated by generation of reactive oxygen species (ROS). Platelet NADPH oxidase-1 (Nox-1) contributes to ROS generation and thrombus formation downstream of the collagen receptor GPVI. Objectives We aimed to investigate whether PDEVs contain Nox-1 and whether this is relevant for PDEV-induced platelet activation. Methods PDEVs were isolated through serial centrifugation after platelet activation with thrombin receptor agonist TRAP-6 (activated PDEVs) or in the absence of agonist (resting PDEVs). The physical properties of PDEVs were analyzed through nanoparticle tracking analysis. Nox-1 levels, fibrinogen binding and P-selectin exposure were measured using flow cytometry, and protein levels quantified by immunoblot analysis. ROS were quantified using DCF fluorescence and electron paramagnetic resonance. Results Nox-1 was found to be increased on the platelet outer membrane upon activation and was present in PDEVs. PDEVs induced platelet activation, while co-addition of GPVI agonist collagen-related peptide (CRP) did not potentiate this response. PDEVs were shown to be able to generate superoxide in a process at least partially mediated by Nox-1, while Nox-1 inhibition with ML171 (also known as 2-APT) did not influence PDEV production. Finally, inhibition of Nox-1 abrogated PDEV-mediated platelet activation. Conclusions PDEVs are able to generate superoxide, bind to and activate platelets in a process mediated by Nox-1. These data provide novel mechanisms by which Nox-1 potentiates platelet responses, thus proposing Nox-1 inhibition as a feasible strategy to treat and prevent thrombotic diseases., Graphical abstract Image 1, Highlights • Activated platelets have increased NADPH oxidase-1 (Nox-1) exposure on the outer membrane. • Platelet-derived extracellular vesicles (PDEVs) express Nox-1 and generate superoxide in a process mediated by Nox-1. • PDEVs bind and activate platelets in a Nox-1-dependent manner.
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- 2021
105. Regulation of Ascorbate-Glutathione Pathway in Mitigating Oxidative Damage in Plants under Abiotic Stress
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Mirza Hasanuzzaman, M. H. M. Borhannuddin Bhuyan, Taufika Islam Anee, Khursheda Parvin, Kamrun Nahar, Jubayer Al Mahmud, and Masayuki Fujita
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antioxidant defense ,free radicals ,glyoxalase system ,hydrogen peroxide ,plant abiotic stress ,reactive oxygen species ,redox biology ,stress signaling ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Reactive oxygen species (ROS) generation is a usual phenomenon in a plant both under a normal and stressed condition. However, under unfavorable or adverse conditions, ROS production exceeds the capacity of the antioxidant defense system. Both non-enzymatic and enzymatic components of the antioxidant defense system either detoxify or scavenge ROS and mitigate their deleterious effects. The Ascorbate-Glutathione (AsA-GSH) pathway, also known as Asada–Halliwell pathway comprises of AsA, GSH, and four enzymes viz. ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase, play a vital role in detoxifying ROS. Apart from ROS detoxification, they also interact with other defense systems in plants and protect the plants from various abiotic stress-induced damages. Several plant studies revealed that the upregulation or overexpression of AsA-GSH pathway enzymes and the enhancement of the AsA and GSH levels conferred plants better tolerance to abiotic stresses by reducing the ROS. In this review, we summarize the recent progress of the research on AsA-GSH pathway in terms of oxidative stress tolerance in plants. We also focus on the defense mechanisms as well as molecular interactions.
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- 2019
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106. Disruption of mitochondrial redox homeostasis as a cellular signal
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Cvetko, Filip
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Mitochondrial biology ,Redox Biology ,ROS - Abstract
Mitochondria are crucial components of eukaryotic cells and exchange signalling molecules, metabolites, proteins and lipids with the rest of the cell. The organelle is key for energy metabolism as they provide most of the cellular ATP through oxidative phosphorylation and regulate intermediate metabolism. Mitochondria are also a major source of reactive oxygen species (ROS), which are by-products of aerobic respiration and recently recognised as important signalling molecules that control various cellular functions. To avoid the potential damaging effects of ROS, mitochondria contain protein antioxidant systems to help maintain thiol homeostasis. Mitochondria are emerging as an important redox signalling node and are involved in a myriad of signalling pathways, which have a redox component, either through a response to a particular ROS or the shift of the redox state of a responsive group. It is not surprising that mitochondria are therefore heavily regulated by retrograde signalling of the master regulator of cellular antioxidant defence, nuclear factor erythroid-derived 2-related factor 2 (Nrf2). Until now it has not been possible to disentangle the overlapping effects of mitochondrial ROS signalling compared to a redox signal stemming from disruption of mitochondrial thiol homeostasis. Furthermore, it is important to distinguish between disturbing the cytosolic and mitochondrial protein antioxidant systems. I characterised the effects of mitochondrial thiol homeostasis disruption on mitochondrial physiology with MitoCDNB, showing mitochondrial fission. I found that selective disruption of the mitochondrial glutathione pool and inhibition of its thioredoxin system led to Nrf2 activation, while using MitoPQ to enhance production of mitochondrial superoxide and hydrogen peroxide alone did not. To further our understanding of how mitochondrial redox homeostasis is sensed in the cytoplasm and signalled to the nucleus I used an RNAseq approach to investigate the intricacies of early mitochondrial retrograde signalling.
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- 2022
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107. On the Origin of Superoxide Dismutase: An Evolutionary Perspective of Superoxide-Mediated Redox Signaling.
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Case, Adam J.
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SUPEROXIDE dismutase ,REACTIVE oxygen species ,OXIDATIVE stress ,ENZYMES ,HYDROGEN peroxide - Abstract
The field of free radical biology originated with the discovery of superoxide dismutase (SOD) in 1969. Over the last 5 decades, a plethora of research has been performed in species ranging from bacteria to mammals that has elucidated the molecular reaction, subcellular location, and specific isoforms of SOD. However, while humans have only begun to study this class of enzymes over the past 50 years, it has been estimated that these enzymes have existed for billions of years, and may be some of the original enzymes found in primitive life. As life evolved over this expanse of time, these enzymes have taken on new and different functional roles potentially in contrast to how they were originally derived. Herein, examination of the evolutionary history of these enzymes provides both an explanation and further inquiries into the modern-day role of SOD in physiology and disease. [ABSTRACT FROM AUTHOR]
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- 2017
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108. Redox biology of Leishmania and macrophage targeted nanoparticles for therapy.
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Sarwar, Hafiz Shoaib, Akhtar, Sohail, Sohail, Muhammad Farhan, Naveed, Zaeema, Rafay, Muhammad, Nadhman, Akhtar, Yasinzai, Masoom, and Shahnaz, Gul
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Intramacrophage parasite ' Leishmania' has developed various mechanisms for proficient uptake into macrophages and phagosome regulation to avoid macrophage's oxidative burst induced by peroxide, hydroxyl radical, hypochlorous acid and peroxynitrite production. One major barrier for impairing the accession of old fashioned anti-Leishmanial drugs is intrinsic incapability to pass through cell membranes and limiting their abilities to ultimately destroy intracellular pathogens. Receptor-mediated targeted drug delivery to the macrophages by using nanoparticles emerges as promising strategy to improve therapeutic efficacy of old-fashioned drug. Receptor-mediated targeted nanoparticles can migrate across the cell membrane barriers and release enclosed drug cargo at sites of infection. This review is focusing on Leishmania-macrophage signaling alterations, its association with drug resistance and role of nanoparticles for receptor mediated macrophage targeting. [ABSTRACT FROM AUTHOR]
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- 2017
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109. Crystal structures and atomic model of NADPH oxidase.
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Magnani, Francesca, Nenci, Simone, Fananas, Elisa Millana, Ceccon, Marta, Romero, Elvira, Fraaije, Marco W., and Mattevi, Andrea
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NADPH oxidase , *REACTIVE oxygen species , *OXIDATION-reduction reaction , *FLAVIN adenine dinucleotide , *COFACTORS (Biochemistry) , *CELL proliferation , *HEMOPROTEINS - Abstract
NADPH oxidases (NOXs) are the only enzymes exclusively dedicated to reactive oxygen species (ROS) generation. Dysregulation of these polytopic membrane proteins impacts the redox signaling cascades that control cell proliferation and death. We describe the atomic crystal structures of the catalytic flavin adenine dinucleotide (FAD)- and heme-binding domains of Cylindrospermum stagnale NOX5. The two domains form the core subunit that is common to all seven members of the NOX family. The domain structures were then docked in silico to provide a generic model for the NOX family. A linear arrangement of cofactors (NADPH, FAD, and two membraneembedded heme moieties) injects electrons from the intracellular side across the membrane to a specific oxygen-binding cavity on the extracytoplasmic side. The overall spatial organization of critical interactions is revealed between the intracellular loops on the transmembrane domain and the NADPH-oxidizing dehydrogenase domain. In particular, the C terminus functions as a toggle switch, which affects access of the NADPH substrate to the enzyme. The essence of this mechanistic model is that the regulatory cues conformationally gate NADPH-binding, implicitly providing a handle for activating/deactivating the very first step in the redox chain. Such insight provides a framework to the discovery of much needed drugs that selectively target the distinct members of the NOX family and interfere with ROS signaling. [ABSTRACT FROM AUTHOR]
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- 2017
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110. ROS Are Good.
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Mittler, Ron
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REACTIVE oxygen species , *AEROBIC metabolism , *DISEASE progression , *CELLULAR signal transduction , *CELL proliferation , *PLANTS , *OXIDATIVE stress - Abstract
Reactive oxygen species (ROS) are thought to play a dual role in plant biology. They are required for many important signaling reactions, but are also toxic byproducts of aerobic metabolism. Recent studies revealed that ROS are necessary for the progression of several basic biological processes including cellular proliferation and differentiation. Moreover, cell death–that was previously thought to be the outcome of ROS directly killing cells by oxidation, in other words via oxidative stress–is now considered to be the result of ROS triggering a physiological or programmed pathway for cell death. This Opinion focuses on the possibility that ROS are beneficial to plants, supporting cellular proliferation, physiological function, and viability, and that maintaining a basal level of ROS in cells is essential for life. [ABSTRACT FROM AUTHOR]
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- 2017
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111. Commentary: On the merit of an early contributor of the "Preparation for Oxidative Stress" (POS) theory.
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Moreira, Daniel C., Campos, Élida G., Giraud-Billoud, Maximiliano, Storey, Kenneth B., and Hermes-Lima, Marcelo
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HYPOXIA (Water) , *OXIDATIVE stress , *TRANSCRIPTION factors - Abstract
This commentary acknowledges the contributions of the Ukrainian biologist, Dr. Volodymyr Lushchak, to the understanding of the physiological adaptive strategy called "Preparation for Oxidative Stress" (POS). In the 1990s, various studies revealed that activities of antioxidant enzymes rose in animals under hypometabolic conditions. These timely observations allowed scientists to propose that this increase could prepare animals for reoxygenation events following the release of oxygen restriction, but in doing so, would trigger oxidative damage, hence the use of the term "preparation". Over next 25 years, the phenomenon was described in detail in more than one hundred studies of animals under conditions of aestivation, hypoxia/anoxia, freezing, severe dehydration, ultraviolet exposure, air exposure of water-breathing animals, salinity stress, and others. The POS phenomenon remained without a mechanistic explanation until 2013, when it was proposed that a small increase in oxyradical formation during hypoxia exposure (in hypoxia-tolerant animals) could activate redox-sensitive transcription factors that, in turn, would initiate transcription and translation of antioxidant enzymes. Dr. Lushchak, who studied goldfish under severe hypoxia in the 1990s, had actually proposed the increased production of oxyradicals under this condition and concluded that it would lead to an upregulation of antioxidant enzymes, the hallmark of the POS strategy. However, his research partner at the time, Dr. Hermes-Lima, thought the idea did not have sufficient evidence to support it and recommended the removal of this explanation. In those days, the main line of thinking was that increased oxyradical formation under hypoxia was "impossible". So, as it turns out, the ideas of Dr. Lushchak were well ahead of his time. It then took >10 years before the biochemical and molecular mechanisms responsible for triggering the POS response were clarified. In the present article, this fascinating history is described to highlight Dr. Lushchak's contributions and insights about the POS theory. [ABSTRACT FROM AUTHOR]
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- 2023
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112. In vivo noninvasive mitochondrial redox assessment of the optic nerve head to predict disease.
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Cakir B, Tomita Y, Yagi H, Romfh P, Allen W, Ko M, Chen P, Fu Z, Vakhshoori D, and Smith LEH
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Eye diseases are diagnosed by visualizing often irreversible structural changes occurring late in disease progression, such as retinal ganglion cell loss in glaucoma. The retina and optic nerve head have high mitochondrial energy need. Early mitochondrial/energetics dysfunction may predict vulnerability to permanent structural changes. In the in vivo murine eye, we used light-based resonance Raman spectroscopy (RRS) to assess noninvasively the redox states of mitochondria and hemoglobin which reflect availability of electron donors (fuel) and acceptors (oxygen). As proof of principle, we demonstrated that the mitochondrial redox state at the optic nerve head correlates with later retinal ganglion loss after acute intraocular pressure (IOP) elevation. This technology can potentially map the metabolic health of eye tissue in vivo complementary to optical coherence tomography, defining structural changes. Early detection (and normalization) of mitochondrial dysfunction before irreversible damage could lead to prevention of permanent neural loss., (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)
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- 2023
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113. A tale of two gases: NO and H2S, foes or friends for life?
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Gopi K. Kolluru, Xinggui Shen, and Christopher G. Kevil
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Thiol ,Redox biology ,Cardiovascular disease ,Vascular biology ,Chemistry ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Nitric oxide (NO) and hydrogen sulfide (H2S) have emerged as dominant redox regulators of numerous aspects of cellular and physiological functions within several organ systems included cardiovascular, immune and neurological tissues. Recent studies have begun to reveal that these two gaseous molecules may have redundant or overlapping pathophysiological functions often involving similar molecular targets. However, it remains less clear when and how NO and H2S may interact under biological and disease processes. In this graphical review, we discuss the current understanding of NO and H2S interactions and how they may functionally influence each other and what this may mean for biology and mechanisms of disease.
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- 2013
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114. Redox biology of hydrogen sulfide: Implications for physiology, pathophysiology, and pharmacology
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Asaf Stein and Shannon M. Bailey
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Hydrogen sulfide ,Redox biology ,Oxygen ,Oxidative stress ,Mitochondria ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Hydrogen sulfide (H2S) has emerged as a critical mediator of multiple physiological processes in mammalian systems. The pathways involved in the production, consumption, and mechanism of action of H2S appear to be sensitive to alterations in the cellular redox state and O2 tension. Indeed, the catabolism of H2S through a putative oxidation pathway, the sulfide quinone oxido-reductase system, is highly dependent on O2 tension. Dysregulation of H2S homeostasis has also been implicated in numerous pathological conditions and diseases. In this review, the chemistry and the main physiological actions of H2S are presented. Some examples highlighting the cytoprotective actions of H2S within the context of cardiovascular disease are also reported. Elucidation of the redox biology of H2S will enable the development of new pharmacological agents based on this intriguing new redox cellular signal.
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- 2013
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115. Mia40 is a trans-site receptor that drives protein import into the mitochondrial intermembrane space by hydrophobic substrate binding
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Valentina Peleh, Emmanuelle Cordat, and Johannes M Herrmann
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mitochondria ,redox biology ,Mia40 ,protein import ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Many proteins of the mitochondrial IMS contain conserved cysteines that are oxidized to disulfide bonds during their import. The conserved IMS protein Mia40 is essential for the oxidation and import of these proteins. Mia40 consists of two functional elements: an N-terminal cysteine-proline-cysteine motif conferring substrate oxidation, and a C-terminal hydrophobic pocket for substrate binding. In this study, we generated yeast mutants to dissect both Mia40 activities genetically and biochemically. Thereby we show that the substrate-binding domain of Mia40 is both necessary and sufficient to promote protein import, indicating that trapping by Mia40 drives protein translocation. An oxidase-deficient Mia40 mutant is inviable, but can be partially rescued by the addition of the chemical oxidant diamide. Our results indicate that Mia40 predominantly serves as a trans-site receptor of mitochondria that binds incoming proteins via hydrophobic interactions thereby mediating protein translocation across the outer membrane by a ‘holding trap’ rather than a ‘folding trap’ mechanism.
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- 2016
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116. Foundations of plasmas for medical applications
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T von Woedtke, M Laroussi, M Gherardi, Von Woedtke T., Laroussi M., and Gherardi M.
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low temperature plasma ,cold atmospheric pressure plasma (CAP) ,cancer ,wound healing ,reactive specie ,plasma medicine ,reactive species ,Condensed Matter Physics ,redox biology - Abstract
Plasma medicine refers to the application of nonequilibrium plasmas at approximately body temperature, for therapeutic purposes. Nonequilibrium plasmas are weakly ionized gases which contain charged and neutral species and electric fields, and emit radiation, particularly in the visible and ultraviolet range. Medically-relevant cold atmospheric pressure plasma (CAP) sources and devices are usually dielectric barrier discharges and nonequilibrium atmospheric pressure plasma jets. Plasma diagnostic methods and modelling approaches are used to characterize the densities and fluxes of active plasma species and their interaction with surrounding matter. In addition to the direct application of plasma onto living tissue, the treatment of liquids like water or physiological saline by a CAP source is performed in order to study specific biological activities. A basic understanding of the interaction between plasma and liquids and bio-interfaces is essential to follow biological plasma effects. Charged species, metastable species, and other atomic and molecular reactive species first produced in the main plasma ignition are transported to the discharge afterglow to finally be exposed to the biological targets. Contact with these liquid-dominated bio-interfaces generates other secondary reactive oxygen and nitrogen species (ROS, RNS). Both ROS and RNS possess strong oxidative properties and can trigger redox-related signalling pathways in cells and tissue, leading to various impacts of therapeutic relevance. Dependent on the intensity of plasma exposure, redox balance in cells can be influenced in a way that oxidative eustress leads to stimulation of cellular processes or oxidative distress leads to cell death. Currently, clinical CAP application is realized mainly in wound healing. The use of plasma in cancer treatment (i.e. plasma oncology) is a currently emerging field of research. Future perspectives and challenges in plasma medicine are mainly directed towards the control and optimization of CAP devices, to broaden and establish its medical applications, and to open up new plasma-based therapies in medicine.
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- 2022
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117. Plasma, cancer, immunity
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Sander Bekeschus and Ramona Clemen
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reactive oxygen species ,Acoustics and Ultrasonics ,T-cells ,cold physical plasma ,oncology ,Condensed Matter Physics ,immunity ,redox biology ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Albeit heavily investigated for several decades already, the importance of the immune system in targeting cancer has received wide clinical attention only in recent years. This is partly because of long-standing rather traditional concepts on tumor biology on the one hand and the complexity of the immune system and its processes on the other. The viewpoint of evaluating existing and emerging approaches in oncology based on toxicity to tumors and the ability to engage antitumor-immunity is gaining ground across several disciplines. Along those lines, cold physical plasma was suggested as potential anticancer tool more than a decade ago, but solid evidence of the immune system playing a role in plasma cancer treatment only emerged in recent years. Moreover, plasma may support cancer immunotherapies in the future. Cancer immunotherapies are systemic treatments with biologicals that were reported to synergize with existing local physical modalities before, such as radiotherapy and photodynamic therapy. This review outlines key concepts in oncology, immunology, and tumor therapy, links them to plasma research, and discusses immuno-oncological consequences. Finally, promising future clinical applications are summarized. Synoptically, first scientific evidence supports an immuno-oncological dimension of plasma cancer treatment in selected instances, but robust clinical evidence is still lacking. More basic and clinical research is needed to determine the immuno-molecular mechanisms and detailed plasma application modalities to facilitate real patient benefit in the long term.
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- 2022
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118. Intraplaque Myeloperoxidase Activity as Biomarker of Unstable Atheroma and Adverse Clinical Outcomes in Human Atherosclerosis.
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Nadel J, Tumanov S, Kong SMY, Chen W, Giannotti N, Sivasubramaniam V, Rashid I, Ugander M, Jabbour A, and Stocker R
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Background: The detection of unstable atherosclerosis remains elusive. Intraplaque myeloperoxidase (MPO) activity causes plaque destabilization in preclinical models, holding promise for clinical translation as a novel imaging biomarker., Objectives: The purpose of this study was to assess whether MPO activity is greater in unstable human plaques, how this relates to cardiovascular events and current/emerging non-invasive imaging techniques., Methods: Thirty-one carotid endarterectomy specimens and 12 coronary trees were collected. MPO activity was determined in 88 individual samples through the conversion of hydroethidine to the MPO-specific adduct 2-chloroethidium and compared with macroscopic validation, histology, clinical outcomes, and computed tomography-derived high and low attenuation plaques and perivascular adipose tissue. Non-parametric statistical analysis utilizing Mann-Whitney U and Kruskal-Wallis tests for univariate and group comparisons were performed., Results: Unstable compared with stable plaque had higher MPO activity (carotid endarterectomy: n = 26, 4.2 ± 3.1 vs 0.2 ± 0.3 nmol/mgp; P < 0.0001; coronary: n = 17, 0.6 ± 0.5 vs 0.001 ± 0.003 nmol/mgp; P = 0.0006). Asymptomatic, stroke-free patients had lower MPO activity compared to those with symptoms or ipsilateral stroke (n = 12, 3.7 ± 2.1 vs 0.1 ± 0.2 nmol/mgp; P = 0.002). Computed tomography-determined plaque attenuation did not differentiate MPO activity (n = 30, 0.1 ± 0.1 vs 0.2 ± 0.3 nmol/mgp; P = 0.23) and MPO activity was not found in perivascular adipose tissue., Conclusions: MPO is active within unstable human plaques and correlates with symptomatic carotid disease and stroke, yet current imaging parameters do not identify plaques with active MPO. As intraplaque MPO activity can be imaged non-invasively through novel molecular imaging probes, ongoing investigations into its utility as a diagnostic tool for high-risk atherosclerosis is warranted., Competing Interests: Dr Nadel is supported by scholarships from the 10.13039/501100000925National Health & Medical Research Council of Australia, 10.13039/501100001030National Heart Foundation, and 10.13039/501100001773University of New South Wales. Dr Stocker has received in-kind support from 10.13039/100004325AstraZeneca related to the development of MPO inhibitors, Program and Fellowship Grants from 10.13039/501100000925National Health & Medical Research Council of Australia, and Senior Scientist Grant from 10.13039/501100009287NSW Health.PERSPECTIVESCOMPETENCY IN MEDICAL KNOWLEDGE: MPO activity is higher in unstable than stable human coronary and carotid plaques, correlates with symptomatic carotid disease and stroke, and current non-invasive imaging techniques do not appear to reliably determine active MPO. TRANSLATIONAL OUTLOOK 1: As intraplaque MPO activity appears to be a hallmark of unstable human atherosclerosis and can be imaged non-invasively, further investigation into its potential utility as a diagnostic and therapeutic target is warranted. TRANSLATIONAL OUTLOOK 2: These data are supportive of preclinical data and reinforce the basis of planned Phase I and II clinical trials looking at an MPO-based molecular positron emission tomography probe for the detection of high-risk atherosclerosis., (© 2023 The Authors.)
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- 2023
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119. Plasma-Like Culture Medium for the Study of Viruses.
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Golikov MV, Bartosch B, Smirnova OA, Ivanova ON, and Ivanov AV
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- Animals, Humans, Cell Line, Virus Replication, Mammals, Culture Media, Plasma, Viruses, Virus Diseases
- Abstract
Viral infections attract more and more attention, especially after the emergence of novel zoonotic coronaviruses and the monkeypox virus over the last 2 decades. Research on viruses is based to a great extent on mammalian cell lines that are permissive to the respective viruses. These cell lines are usually cultivated according to the protocols established in the 1950s to 1970s, although it is clear that classical media have a significant imprint on cell growth, phenotype, and especially metabolism. So, recently in the field of biochemistry and metabolomics novel culture media have been developed that resemble human blood plasma. As perturbations in metabolic and redox pathways during infection are considered significant factors of viral pathogenesis, these novel medium formulations should be adapted by the virology field. So far, there are only scarce data available on viral propagation efficiencies in cells cultivated in plasma-like media. But several groups have presented convincing data on the use of such media for cultivation of uninfected cells. The aim of the present review is to summarize the current state of research in the field of plasma-resembling culture media and to point out the influence of media on various cellular processes in uninfected cells that may play important roles in viral replication and pathogenesis in order to sensitize virology research to the use of such media.
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- 2023
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120. High throughput drug screening identifies resveratrol as suppressor of hepatic SELENOP expression.
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Hackler J, Demircan K, Chillon TS, Sun Q, Geisler N, Schupp M, Renko K, and Schomburg L
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- Resveratrol pharmacology, Drug Evaluation, Preclinical, Liver metabolism, Selenoproteins genetics, Selenoprotein P genetics, Selenium metabolism
- Abstract
Introduction: Selenium (Se) is an essential trace element that exerts its effects mainly as the proteinogenic amino acid selenocysteine within a small set of selenoproteins. Among all family members, selenoprotein P (SELENOP) constitutes a particularly interesting protein as it serves as a biomarker and serum Se transporter from liver to privileged tissues. SELENOP expression is tightly regulated by dietary Se intake, inflammation, hypoxia and certain substances, but a systematic drug screening has hitherto not been performed., Methods: A compound library of 1861 FDA approved clinically relevant drugs was systematically screened for interfering effects on SELENOP expression in HepG2 cells using a validated ELISA method. Dilution experiments were conducted to characterize dose-responses. A most potent SELENOP inhibitor was further characterized by RNA-seq analysis to assess effect-associated biochemical pathways., Results: Applying a 2-fold change threshold, 236 modulators of SELENOP expression were identified. All initial hits were replicated as biological triplicates and analyzed for effects on cell viability. A set of 38 drugs suppressed SELENOP expression more than three-fold, among which were cancer drugs, immunosuppressants, anti-infectious drugs, nutritional supplements and others. Considering a 90% cell viability threshold, resveratrol, vidofludimus, and antimony potassium-tartrate were the most potent substances with suppressive effects on extracellular SELENOP concentrations. Resveratrol suppressed SELENOP levels dose-dependently in a concentration range from 0.8 μM to 50.0 μM, without affecting cell viability, along with strong effects on key genes controlling metabolic pathways and vesicle trafficking., Conclusion: The results highlight an unexpected direct effect of the plant stilbenoid resveratrol, known for its antioxidative and health-promoting effects, on the central Se transport protein. The suppressive effects on SELENOP may increase liver Se levels and intracellular selenoprotein expression, thereby conferring additional protection to hepatocytes at the expense of systemic Se transport. Further physiological effects from this interaction require analyses in vivo and by clinical studies., Competing Interests: Declaration of competing interest L.S. holds shares of selenOmed GmbH, a company involved in Se status assessment. The other authors declare no competing interests., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2023
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121. Ebselen and analogs as inhibitors of Bacillus anthracis thioredoxin reductase and bactericidal antibacterials targeting Bacillus species, Staphylococcus aureus and Mycobacterium tuberculosis.
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Gustafsson, Tomas N., Osman, Harer, Werngren, Jim, Hoffner, Sven, Engman, Lars, and Holmgren, Arne
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THIOREDOXIN reductase (NADPH) , *ANTIBACTERIAL agents , *ENZYME inhibitors , *BACILLUS anthracis , *STAPHYLOCOCCUS aureus infections , *TUBERCULOSIS prevention , *TARGETED drug delivery , *THERAPEUTICS - Abstract
Background Bacillus anthracis is the causative agent of anthrax, a disease associated with a very high mortality rate in its invasive forms. Methods We studied a number of ebselen analogs as inhibitors of B. anthracis thioredoxin reductase and their antibacterial activity on Bacillus subtilis , Staphylococcus aureus , Bacillus cereus and Mycobacterium tuberculosis . Results The most potent compounds in the series gave IC50 values down to 70 nM for the pure enzyme and minimal inhibitory concentrations (MICs) down to 0.4 μM (0.12 μg/ml) for B. subtilis , 1.5 μM (0.64 μg/ml) for S. aureus , 2 μM (0.86 μg/ml) for B. cereus and 10 μg/ml for M. tuberculosis . Minimal bactericidal concentrations (MBCs) were found at 1–1.5 times the MIC, indicating a general, class-dependent, bactericidal mode of action. The combined bacteriological and enzymological data were used to construct a preliminary structure–activity-relationship for the benzoisoselenazol class of compounds. When S. aureus and B. subtilis were exposed to ebselen, we were unable to isolate resistant mutants on both solid and in liquid medium suggesting a high resistance barrier. Conclusions These results suggest that ebselen and analogs thereof could be developed into a novel antibiotic class, useful for the treatment of infections caused by B. anthracis , S. aureus , M. tuberculosis and other clinically important bacteria. Furthermore, the high barrier against resistance development is encouraging for further drug development. General significance We have characterized the thioredoxin system from B. anthracis as a novel drug target and ebselen and analogs thereof as a potential new class of antibiotics targeting several important human pathogens. [ABSTRACT FROM AUTHOR]
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- 2016
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122. Ebselen, a useful tool for understanding cellular redox biology and a promising drug candidate for use in human diseases.
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Noguchi, Noriko
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ORGANOSELENIUM compounds , *OXIDATION-reduction reaction , *CYTOLOGY , *GLUTATHIONE peroxidase , *HYDROPEROXIDES - Abstract
Ebselen is an organoselenium compound with glutathione peroxidase (GPx)-like hydroperoxide reducing activity. Moreover, ebselen has its own unique reactivity, with functions that GPx does not have, since it reacts with many kinds of thiols other than glutathione. Ebselen may affect the thioredoxin systems, through which it may contribute to regulation of cell function. With high reactivity toward thiols, hydroperoxides, and peroxynitrite, ebselen has been used as a useful tool in research on cellular redox mechanisms. Unlike α-tocopherol, ebselen does not scavenge lipid peroxyl radicals, which is another advantage of ebselen for use as a research tool in comparison with radical scavenging antioxidants. Selenium is not released from the ebselen molecule, which explains the low toxicity of ebselen. To further understand the mechanism of cellular redox biology, it should be interesting to compare the effects of ebselen with that of selenoprotein P, which supplies selenium to GPx. New medical applications of ebselen as a drug candidate for human diseases such as cancer and diabetes mellitus as well as brain stroke and ischemia will be expected. [ABSTRACT FROM AUTHOR]
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- 2016
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123. Hydrogen peroxide and central redox theory for aerobic life: A tribute to Helmut Sies: Scout, trailblazer, and redox pioneer.
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Jones, Dean P.
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HYDROGEN peroxide , *OXIDATION-reduction reaction , *BIOCHEMISTRY , *BIOENERGETICS , *OXIDATIVE stress - Abstract
When Rafael Radi and I wrote about Helmut Sies for the Redox Pioneer series, I was disappointed that the Editor restricted us to the use of “Pioneer” in the title. My view is that Helmut was always ahead of the pioneers: He was a scout discovering paths for exploration and a trailblazer developing strategies and methods for discovery. I have known him for nearly 40 years and greatly enjoyed his collegiality as well as brilliance in scientific scholarship. He made monumental contributions to 20th century physiological chemistry beginning with his first measurement of H 2 O 2 in rat liver. While continuous H 2 O 2 production is dogma today, the concept of H 2 O 2 production in mammalian tissues was largely buried for half a century. He continued this leadership in research on oxidative stress, GSH, selenium, and singlet oxygen, during the timeframe when physiological chemistry and biochemistry transitioned to contemporary 21st century systems biology. His impact has been extensive in medical and health sciences, especially in nutrition, aging, toxicology and cancer. I briefly summarize my interactions with Helmut, stressing our work together on the redox code, a set of principles to link mitochondrial respiration, bioenergetics, H 2 O 2 metabolism, redox signaling and redox proteomics into central redox theory. [ABSTRACT FROM AUTHOR]
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- 2016
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124. Cy-preds: An algorithm and a web service for the analysis and prediction of cysteine reactivity.
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Soylu, İnanç and Marino, Stefano M.
- Abstract
ABSTRACT Cysteine (Cys) is a critically important amino acid, serving a variety of functions within proteins including structural roles, catalysis, and regulation of function through post-translational modifications. Predicting which Cys residues are likely to be reactive is a very sought after feature. Few methods are currently available for the task, either based on evaluation of physicochemical features (e.g., pKa and exposure) or based on similarity with known instances. In this study, we developed an algorithm (named HAL-Cy) which blends previous work with novel implementations to identify reactive Cys from nonreactive. HAL-Cy present two major components: (i) an energy based part, rooted on the evaluation of H-bond network contributions and (ii) a knowledge based part, composed of different profiling approaches (including a newly developed weighting matrix for sequence profiling). In our evaluations, HAL-Cy provided significantly improved performances, as tested in comparisons with existing approaches. We implemented our algorithm in a web service ( Cy-preds), the ultimate product of our work; we provided it with a variety of additional features, tools, and options: Cy-preds is capable of performing fully automated calculations for a thorough analysis of Cys reactivity in proteins, ranging from reactivity predictions (e.g., with HAL-Cy) to functional characterization. We believe it represents an original, effective, and very useful addition to the current array of tools available to scientists involved in redox biology, Cys biochemistry, and structural bioinformatics. Proteins 2016; 84:278-291. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]
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- 2016
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125. Biological signaling by small inorganic molecules.
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Basudhar, Debashree, Ridnour, Lisa A., Cheng, Robert, Kesarwala, Aparna H., Heinecke, Julie, and Wink, David A.
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SMALL molecules , *OXIDATION-reduction reaction , *NITROGEN , *OXYGEN , *HYDROGEN sulfide , *CHEMICAL species - Abstract
Small redox active molecules such as reactive nitrogen and oxygen species and hydrogen sulfide have emerged as important biological mediators that are involved in various physiological and pathophysiological processes. Advancement in understanding of cellular mechanisms that tightly regulate both generation and reactivity of these molecules is central to improved management of various disease states including cancer and cardiovascular dysfunction. Imbalance in the production of redox active molecules can lead to damage of critical cellular components such as cell membranes, proteins and DNA and thus may trigger the onset of disease. These small inorganic molecules react independently as well as in a concerted manner to mediate physiological responses. This review provides a general overview of the redox biology of these key molecules, their diverse chemistry relevant to physiological processes and their interrelated nature in cellular signaling. [ABSTRACT FROM AUTHOR]
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- 2016
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126. Reversible oxidation of phosphatase and tensin homolog (PTEN) alters its interactions with signaling and regulatory proteins.
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Verrastro, Ivan, Tveen-Jensen, Karina, Woscholski, Rudiger, Spickett, Corinne M., and Pitt, Andrew R.
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PHOSPHATASES , *HOMOLOGY (Biochemistry) , *CELLULAR signal transduction , *PROTEIN-protein interactions , *DESMOPLAKIN , *PROTEOMICS - Abstract
Phosphatase and tensin homolog (PTEN) is involved in a number of different cellular processes including metabolism, apoptosis, cell proliferation and survival. It is a redox-sensitive dual-specificity protein phosphatase that acts as a tumor suppressor by negatively regulating the PI3K/Akt pathway. While direct evidence of redox regulation of PTEN downstream signaling has been reported, the effect of PTEN redox status on its protein–protein interactions is poorly understood. PTEN-GST in its reduced and a DTT-reversible H 2 O 2 -oxidized form was immobilized on a glutathione-sepharose support and incubated with cell lysate to capture interacting proteins. Captured proteins were analyzed by LC–MSMS and comparatively quantified using label-free methods. 97 Potential protein interactors were identified, including a significant number that are novel. The abundance of fourteen interactors was found to vary significantly with the redox status of PTEN. Altered binding to PTEN was confirmed by affinity pull-down and Western blotting for Prdx1, Trx, and Anxa2, while DDB1 was validated as a novel interactor with unaltered binding. These results suggest that the redox status of PTEN causes a functional variation in the PTEN interactome. The resin capture method developed had distinct advantages in that the redox status of PTEN could be directly controlled and measured. [ABSTRACT FROM AUTHOR]
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- 2016
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127. The mitochondrial carnitine/acylcarnitine carrier is regulated by hydrogen sulfide via interaction with C136 and C155.
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Giangregorio, Nicola, Tonazzi, Annamaria, Console, Lara, Lorusso, Imma, De Palma, Annalisa, and Indiveri, Cesare
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CARNITINE , *HYDROGEN sulfide , *OXIDATION-reduction reaction , *ORNITHINE , *MUTAGENESIS - Abstract
Background The carnitine/acylcarnitine carrier (CAC or CACT) mediates transport of acylcarnitines into mitochondria for the β-oxidation. CAC possesses Cys residues which respond to redox changes undergoing to SH/disulfide interconversion. Methods The effect of H 2 S has been investigated on the [ 3 H]carnitine/carnitine antiport catalyzed by recombinant or native CAC reconstituted in proteoliposomes. Site-directed mutagenesis was employed for identifying Cys reacting with H 2 S. Results H 2 S led to transport inhibition, which was dependent on concentration, pH and time of incubation. Best inhibition with IC 50 of 0.70 μM was observed at physiological pH after 30–60 min incubation. At longer times of incubation, inhibition was reversed. After oxidation of the carrier by O 2 , transport activity was rescued by H 2 S indicating that the inhibition/activation depends on the initial redox state of the protein. The observed effects were more efficient on the native rat liver transporter than on the recombinant protein. Only the protein containing both C136 and C155 responded to the reagent as the WT. While reduced responses were observed in the mutants containing C136 or C155. Multi-alignment of known mitochondrial carriers, highlighted that only the CAC possesses both Cys residues. This correlates well with the absence of effects of H 2 S on carriers which does not contain the Cys couple. Conclusions Altogether, these data demonstrate that H 2 S regulates the CAC by inhibiting or activating transport on the basis of the redox state of the protein. General significance CAC represents a specific target of H 2 S among mitochondrial carriers in agreement with the presence of a reactive Cys couple. [ABSTRACT FROM AUTHOR]
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- 2016
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128. Redox regulation of autophagy in healthy brain and neurodegeneration.
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Hensley, Kenneth and Harris-White, Marni E.
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NEURODEGENERATION , *BRAIN diseases , *AUTOPHAGY , *CYTOLOGY , *OXIDATIVE stress , *DISEASE progression , *BIOLOGICAL crosstalk - Abstract
Autophagy and redox biochemistry are two major sub disciplines of cell biology which are both coming to be appreciated for their paramount importance in the etiology of neurodegenerative diseases including Alzheimer's disease (AD). Thus far, however, there has been relatively little exploration of the interface between autophagy and redox biology. Autophagy normally recycles macro-molecular aggregates produced through oxidative-stress mediated pathways, and also may reduce the mitochondrial production of reactive oxygen species through recycling of old and damaged mitochondria. Conversely, dysfunction in autophagy initiation, progression or clearance is evidenced to increase aggregation-prone proteins in neural and extraneural tissues. Redox mechanisms of autophagy regulation have been documented at the level of cross-talk between the Nrf2/Keap1 oxidant and electrophilic defense pathway and p62/sequestosome-1 (SQSTM1)-associated autophagy, at least in extraneural tissue; but other mechanisms of redox autophagy regulation doubtless remain to be discovered and the relevance of such processes to maintenance of neural homeostasis remains to be determined. This review summarizes current knowledge regarding the relationship of redox signaling, autophagy control, and oxidative stress as these phenomena relate to neurodegenerative disease. AD is specifically addressed as an example of the theme and as a promising indication for new therapies that act through engagement of autophagy pathways. To exemplify one such novel therapeutic entity, data is presented that the antioxidant and neurotrophic agent lanthionine ketimine-ethyl ester (LKE) affects autophagy pathway proteins including beclin-1 in the 3xTg-AD model of Alzheimer's disease where the compound has been shown to reduce pathological features and cognitive dysfunction. [ABSTRACT FROM AUTHOR]
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- 2015
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129. ROS/RNS Balancing, Aerobic Fermentation Regulation and Cell Cycle Control – a Complex Early Trait (‘CoV-MAC-TED’) for Combating SARS-CoV-2-Induced Cell Reprogramming
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Costa, JH, Mohanapriya, G, Bharadwaj, R, Noceda, C, Thiers, KLL, Aziz, S, Srivastava, S, Oliveira, M, Gupta, KJ, Kumari, A, Sircar, D, Kumar, SR, Achra, A, Sathishkumar, R, Adholeya, Alok, Arnholdt-Schmitt, B, Costa, JH, Mohanapriya, G, Bharadwaj, R, Noceda, C, Thiers, KLL, Aziz, S, Srivastava, S, Oliveira, M, Gupta, KJ, Kumari, A, Sircar, D, Kumar, SR, Achra, A, Sathishkumar, R, Adholeya, Alok, and Arnholdt-Schmitt, B
- Abstract
In a perspective entitled ‘From plant survival under severe stress to anti-viral human defense’ we raised and justified the hypothesis that transcript level profiles of justified target genes established from in vitro somatic embryogenesis (SE) induction in plants as a reference compared to virus-induced profiles can identify differential virus signatures that link to harmful reprogramming. A standard profile of selected genes named ‘ReprogVirus’ was proposed for in vitro-scanning of early virus-induced reprogramming in critical primary infected cells/tissues as target trait. For data collection, the ‘ReprogVirus platform’ was initiated. This initiative aims to identify in a common effort across scientific boundaries critical virus footprints from diverse virus origins and variants as a basis for anti-viral strategy design. This approach is open for validation and extension. In the present study, we initiated validation by experimental transcriptome data available in public domain combined with advancing plant wet lab research. We compared plant-adapted transcriptomes according to ‘RegroVirus’ complemented by alternative oxidase (AOX) genes during de novo programming under SE-inducing conditions with in vitro corona virus-induced transcriptome profiles. This approach enabled identifying a major complex trait for early de novo programming during SARS-CoV-2 infection, called ‘CoV-MAC-TED’. It consists of unbalanced ROS/RNS levels, which are connected to increased aerobic fermentation that links to alpha-tubulin-based cell restructuration and progression of cell cycle. We conclude that anti-viral/anti-SARS-CoV-2 strategies need to rigorously target ‘CoV-MAC-TED’ in primary infected nose and mouth cells through prophylactic and very early therapeutic strategies. We also discuss potential strategies in the view of the beneficial role of AOX for resilient behavior in plants. Furthermore, following the general observation that ROS/RNS equilibration/redox homeostasis is of
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- 2021
130. Azide-based fluorescent probes: imaging hydrogen sulfide in living systems.
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Lin, Vivian S, Lippert, Alexander R, and Chang, Christopher J
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Cells ,Cultured ,Humans ,Hydrogen Sulfide ,Azides ,Vascular Endothelial Growth Factor A ,Fluorescent Dyes ,Microscopy ,Fluorescence ,Cell Culture Techniques ,Staining and Labeling ,Human Umbilical Vein Endothelial Cells ,Azide reduction ,Fluorescence ,Hydrogen sulfide ,Microscopy ,Reaction-based sensing ,Redox biology ,Biochemistry & Molecular Biology ,Biochemistry and Cell Biology - Abstract
Hydrogen sulfide is a redox active sulfur species that is endogenously generated in mammalian systems as an antioxidant and signaling molecule to support cellular function. The fundamental and ubiquitous actions of hydrogen sulfide demand sensitive and specific methods to track this biomolecule as it is produced within living organisms with temporal and spatial regulation. In this context, the hydrogen sulfide-mediated reduction of an azide to an amine is a useful method for organic synthesis, and this reaction has successfully been exploited to yield biocompatible fluorescent probes for hydrogen sulfide detection in vitro and in cells. This chapter provides protocols and guidelines for applying azide-based fluorescence probes to detecting hydrogen sulfide in living systems, including a protocol that was used to detect endogenous hydrogen sulfide in living single cells using a confocal microscope.
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- 2015
131. Chapter Four Azide-Based Fluorescent Probes Imaging Hydrogen Sulfide in Living Systems
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Lin, Vivian S, Lippert, Alexander R, and Chang, Christopher J
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Biochemistry and Cell Biology ,Biological Sciences ,Generic health relevance ,Azides ,Cell Culture Techniques ,Cells ,Cultured ,Fluorescent Dyes ,Human Umbilical Vein Endothelial Cells ,Humans ,Hydrogen Sulfide ,Microscopy ,Fluorescence ,Staining and Labeling ,Vascular Endothelial Growth Factor A ,Azide reduction ,Fluorescence ,Hydrogen sulfide ,Microscopy ,Reaction-based sensing ,Redox biology ,Biochemistry & Molecular Biology ,Biochemistry and cell biology - Abstract
Hydrogen sulfide is a redox active sulfur species that is endogenously generated in mammalian systems as an antioxidant and signaling molecule to support cellular function. The fundamental and ubiquitous actions of hydrogen sulfide demand sensitive and specific methods to track this biomolecule as it is produced within living organisms with temporal and spatial regulation. In this context, the hydrogen sulfide-mediated reduction of an azide to an amine is a useful method for organic synthesis, and this reaction has successfully been exploited to yield biocompatible fluorescent probes for hydrogen sulfide detection in vitro and in cells. This chapter provides protocols and guidelines for applying azide-based fluorescence probes to detecting hydrogen sulfide in living systems, including a protocol that was used to detect endogenous hydrogen sulfide in living single cells using a confocal microscope.
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- 2015
132. Roles of Phase Separation for Cellular Redox Maintenance
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Wataru Kimura and Yuichi Saito
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autophagy ,Cellular respiration ,Cellular homeostasis ,Review ,Protein degradation ,QH426-470 ,medicine.disease_cause ,Redox ,Nrf2 ,03 medical and health sciences ,0302 clinical medicine ,Biological phase ,Lipid droplet ,medicine ,Genetics ,oxidative stress ,redox biology ,Genetics (clinical) ,030304 developmental biology ,0303 health sciences ,Chemistry ,hypoxia ,liquid-liquid phase separation ,Cell biology ,Molecular Medicine ,Signal transduction ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
The oxidation reaction greatly alters characteristics of various cellular components. In exchange for efficient energy production, mitochondrial aerobic respiration substantially increases the risk of excess oxidation of cellular biomolecules such as lipids, proteins, nucleic acids, and numerous small molecules. To maintain a physiologically balanced cellular reduction-oxidation (redox) state, cells utilize a variety of molecular machineries including cellular antioxidants and protein degradation complexes such as the ubiquitin-proteasome system or autophagy. In the past decade, biomolecular liquid-liquid phase separation (LLPS) has emerged as a subject of great interest in the biomedical field, as it plays versatile roles in the maintenance of cellular homeostasis. With regard to redox homeostasis, LLPS arose as a major player in both well-characterized and newly emerging redox pathways. LLPS is involved in direct redox imbalance sensing, signal transduction, and transcriptional regulation. Also, LLPS is at play when cells resist redox imbalance through metabolic switching, translational remodeling, activating the DNA damage response, and segregation of vulnerable lipids and proteins. On the other hand, chronic accumulation of phase-separated molecular condensates such as lipid droplets and amyloid causes neurotoxic outcomes. In this review we enumerate recent progress on understanding how cells utilize LLPS to deal with oxidative stress, especially related to cell survival or pathogenesis, and we discuss future research directions for understanding biological phase separation in cellular redox regulation.
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- 2021
133. Functional analyses of ancestral thioredoxins provide insights into their evolutionary history
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Robin J. Reber, Silvia Napolitano, Rudi Glockshuber, and Marina Rubini
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inorganic chemicals ,0301 basic medicine ,Cytoplasm ,Thioredoxin-Disulfide Reductase ,Thioredoxin reductase ,Context (language use) ,Reductase ,medicine.disease_cause ,Biochemistry ,Evolution, Molecular ,Structure-Activity Relationship ,03 medical and health sciences ,Cytosol ,Thioredoxins ,Molecular evolution ,Escherichia coli ,medicine ,oxidative stress ,Disulfides ,molecular evolution ,thioredoxin ,thioredoxin reductase ,electron transfer ,methionine sulfoxide reductase ,phylogenetic reconstruction ,redox biology ,redox homeostasis ,Molecular Biology ,History, Ancient ,chemistry.chemical_classification ,030102 biochemistry & molecular biology ,Chemistry ,Cell Biology ,Oxidants ,Kinetics ,030104 developmental biology ,Enzyme ,Methionine sulfoxide reductase ,Thioredoxin ,Oxidation-Reduction ,Molecular Biophysics ,NADP - Abstract
Thioredoxin (Trx) is a conserved, cytosolic reductase in all known organisms. The enzyme receives two electrons from NADPH via thioredoxin reductase (TrxR) and passes them on to multiple cellular reductases via disulfide exchange. Despite the ubiquity of thioredoxins in all taxa, little is known about the functions of resurrected ancestral thioredoxins in the context of a modern mesophilic organism. Here, we report on functional in vitro and in vivo analyses of seven resurrected Precambrian thioredoxins, dating back 1–4 billion years, in the Escherichia coli cytoplasm. Using synthetic gene constructs for recombinant expression of the ancestral enzymes, along with thermodynamic and kinetic assays, we show that all ancestral thioredoxins, as today's thioredoxins, exhibit strongly reducing redox potentials, suggesting that thioredoxins served as catalysts of cellular reduction reactions from the beginning of evolution, even before the oxygen catastrophe. A detailed, quantitative characterization of their interactions with the electron donor TrxR from Escherichia coli and the electron acceptor methionine sulfoxide reductase, also from E. coli, strongly hinted that thioredoxins and thioredoxin reductases co-evolved and that the promiscuity of thioredoxins toward downstream electron acceptors was maintained during evolution. In summary, our findings suggest that thioredoxins evolved high specificity for their sole electron donor TrxR while maintaining promiscuity to their multiple electron acceptors., Journal of Biological Chemistry, 294 (38), ISSN:0021-9258, ISSN:1083-351X
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- 2019
134. On the Origin of Superoxide Dismutase: An Evolutionary Perspective of Superoxide-Mediated Redox Signaling
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Adam J. Case
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redox biology ,redox signaling ,oxidative stress ,reactive oxygen species ,hydrogen peroxide ,oxygen ,nitric oxide ,evolution ,great oxidation event ,adaptation ,metabolism ,iron ,copper ,zinc ,manganese ,nickel ,Therapeutics. Pharmacology ,RM1-950 - Abstract
The field of free radical biology originated with the discovery of superoxide dismutase (SOD) in 1969. Over the last 5 decades, a plethora of research has been performed in species ranging from bacteria to mammals that has elucidated the molecular reaction, subcellular location, and specific isoforms of SOD. However, while humans have only begun to study this class of enzymes over the past 50 years, it has been estimated that these enzymes have existed for billions of years, and may be some of the original enzymes found in primitive life. As life evolved over this expanse of time, these enzymes have taken on new and different functional roles potentially in contrast to how they were originally derived. Herein, examination of the evolutionary history of these enzymes provides both an explanation and further inquiries into the modern-day role of SOD in physiology and disease.
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- 2017
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135. Novel functions of peroxiredoxin Q from Deinococcus radiodurans R1 as a peroxidase and a molecular chaperone
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Sung H. Hong, Sangyong Lim, Jong-Hyun Jung, Gun Woong Lee, Seung Sik Lee, Byung Yeoup Chung, Chuloh Cho, Kwang-Woo Jung, and Shubhpreet Kaur
- Subjects
Mutant ,Biophysics ,peroxidase ,Oxidative phosphorylation ,medicine.disease_cause ,Biochemistry ,03 medical and health sciences ,Bacterial Proteins ,Structural Biology ,Genetics ,medicine ,Research Letter ,DR0846 ,Cysteine ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,biology ,Chemistry ,Redox Biology ,030302 biochemistry & molecular biology ,Deinococcus radiodurans ,Cell Biology ,Gene Expression Regulation, Bacterial ,Peroxiredoxins ,molecular chaperone ,biology.organism_classification ,Deinococcus radiodurans R1 ,Research Letters ,Oxidative Stress ,peroxiredoxin Q ,Catalase ,Mutation ,biology.protein ,Deinococcus ,Peroxiredoxin ,Oxidative stress ,Heat-Shock Response ,Peroxidase ,Molecular Chaperones - Abstract
Deinococcus radiodurans R1 is extremely resistant to ionizing radiation and oxidative stress. In this study, we characterized DR0846, a candidate peroxiredoxin in D. radiodurans. DR0846 is a peroxiredoxin Q containing two conserved cysteine residues. DR0846 exists mainly in monomeric form with an intramolecular disulfide bond between the two cysteine residues. We found that DR0846 functions as a molecular chaperone as well as a peroxidase. A mutational analysis indicates that the two cysteine residues are essential for enzymatic activity. A double-deletion mutant lacking DR0846 and catalase DR1998 exhibits decreased oxidative and heat shock stress tolerance with respect to the single mutants or the wild-type cells. These results suggest that DR0846 contributes to resistance against oxidative and heat stresses in D. radiodurans.
- Published
- 2018
136. Protein Disulphide Isomerase and NADPH Oxidase 1 Cooperate to Control Platelet Function and Are Associated with Cardiometabolic Disease Risk Factors
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Jonathan M. Gibbins, Tanya Sage, Giordano Pula, Neline Kriek, Gemma Little, and Renato Simões Gaspar
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0301 basic medicine ,inorganic chemicals ,medicine.medical_specialty ,Physiology ,Clinical Biochemistry ,030204 cardiovascular system & hematology ,Biochemistry ,Article ,metabolic syndrome ,Collagen receptor ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Calcium flux ,medicine ,protein disulphide isomerase ,Platelet ,Molecular Biology ,redox biology ,Protein kinase C ,NADPH oxidase ,biology ,Chemistry ,lcsh:RM1-950 ,Fibrinogen binding ,NADPH Oxidase 1 ,Cell Biology ,respiratory system ,nervous system diseases ,body regions ,030104 developmental biology ,Endocrinology ,lcsh:Therapeutics. Pharmacology ,platelets ,biology.protein ,cardiovascular system ,GPVI - Abstract
Background: Protein disulphide isomerase (PDI) and NADPH oxidase 1 (Nox-1) regulate platelet function and reactive oxygen species (ROS) generation, suggesting potentially interdependent roles. Increased platelet reactivity and ROS production have been correlated with cardiometabolic disease risk factors. Objectives: To establish whether PDI and Nox-1 cooperate to control platelet function. Methods: Immunofluorescence microscopy was utilised to determine expression and localisation of PDI and Nox-1. Platelet aggregation, fibrinogen binding, P-selectin exposure, spreading and calcium mobilization were measured as markers of platelet function. A cross-sectional population study (n = 136) was conducted to assess the relationship between platelet PDI and Nox-1 levels and cardiometabolic risk factors. Results: PDI and Nox-1 co-localized upon activation induced by the collagen receptor GPVI. Co-inhibition of PDI and Nox-1 led to additive inhibition of GPVI-mediated platelet aggregation, activation and calcium flux. This was confirmed in murine Nox-1−/− platelets treated with PDI inhibitor bepristat, without affecting bleeding. PDI and Nox-1 together contributed to GPVI signalling that involved the phosphorylation of p38 MAPK, p47phox, PKC and Akt. Platelet PDI and Nox-1 levels were upregulated in obesity, with platelet Nox-1 also elevated in hypertensive individuals. Conclusions: We show that PDI and Nox-1 cooperate to control platelet function and are associated with cardiometabolic risk factors.
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- 2021
137. Interplay between cellular redox oscillations and circadian clocks.
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Rey, G. and Reddy, A. B.
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OXIDATION-reduction reaction , *BIOLOGICAL rhythms , *CELL cycle , *ACTIVITY patterns (Biology) - Abstract
The circadian clock is a cellular timekeeping mechanism that helps organisms from bacteria to humans to organize their behaviour and physiology around the solar cycle. Current models for circadian timekeeping incorporate transcriptional/translational feedback loop mechanisms in the predominant model systems. However, recent evidence suggests that non-transcriptional oscillations such as metabolic and redox cycles may play a fundamental role in circadian timekeeping. Peroxiredoxins, an antioxidant protein family, undergo rhythmic oxidation on the circadian time scale in a variety of species, including bacteria, insects and mammals, but also in red blood cells, a naturally occurring, non-transcriptional system. The profound interconnectivity between circadian and redox pathways strongly suggests that a conserved timekeeping mechanism based on redox cycles could be integral to generating circadian rhythms. [ABSTRACT FROM AUTHOR]
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- 2015
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138. ROSics: Chemistry and proteomics of cysteine modifications in redox biology.
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Kim, Hee-Jung, Lee, Kong-Joo, Ha, Sura, and Lee, Hee Yoon
- Subjects
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REACTIVE oxygen species , *POST-translational modification , *CYSTEINE , *MASS spectrometry , *PROTEOMICS , *DISULFIDES , *THIOSULFURIC acid - Abstract
Post-translational modifications (PTMs) occurring in proteins determine their functions and regulations. Proteomic tools are available to identify PTMs and have proved invaluable to expanding the inventory of these tools of nature that hold the keys to biological processes. Cysteine (Cys), the least abundant (1-2%) of amino acid residues, are unique in that they play key roles in maintaining stability of protein structure, participating in active sites of enzymes, regulating protein function and binding to metals, among others. Cys residues are major targets of reactive oxygen species (ROS), which are important mediators and modulators of various biological processes. It is therefore necessary to identify the Cys-containing ROS target proteins, as well as the sites and species of their PTMs. Cutting edge proteomic tools which have helped identify the PTMs at reactive Cys residues, have also revealed that Cys residues are modified in numerous ways. These modifications include formation of disulfide, thiosulfinate and thiosulfonate, oxidation to sulfenic, sulfinic, sulfonic acids and thiosulfonic acid, transformation to dehydroalanine (DHA) and serine, palmitoylation and farnesylation, formation of chemical adducts with glutathione, 4-hydroxynonenal and 15-deoxy PGJ2, and various other chemicals. We present here, a review of relevant ROS biology, possible chemical reactions of Cys residues and details of the proteomic strategies employed for rapid, efficient and sensitive identification of diverse and novel PTMs involving reactive Cys residues of redox-sensitive proteins. We propose a new name, 'ROSics,' for the science which describes the principles of mode of action of ROS at molecular levels. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Rapid Commun. Mass Spec Rev 34:184-208, 2015. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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139. Biological chemistry of superoxide radicals
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Winterbourn, Christine C.
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- 2020
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140. An ex vivo Approach to Assess Mitochondrial ROS by Flow Cytometry in AAV-tagged Astrocytes in Adult Mice
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Ministerio de Economía y Competitividad (España), Instituto de Salud Carlos III, Fundación BBVA, Fundación Ramón Areces, Junta de Castilla y León, Bolaños, Juan P., Vicente-Gutiérrez, Carlos, Ministerio de Economía y Competitividad (España), Instituto de Salud Carlos III, Fundación BBVA, Fundación Ramón Areces, Junta de Castilla y León, Bolaños, Juan P., and Vicente-Gutiérrez, Carlos
- Abstract
Mitochondrial reactive oxygen species (mROS) are naturally produced signalling molecules extremely relevant for understanding both health- and disease-associated biological processes. The study of mROS in the brain is currently underway to decipher their physiopathological roles and contributions in neurological diseases. Recent advances in this field have highlighted the importance of studying mROS signalling and redox biology at the cellular level. Neurons are especially sensitive to the harmful effects of excess mROS while astrocytic mROS have been shown to play a relevant physiological role in cerebral homeostasis and behaviour. However, given the complexity of the brain, investigating mROS formation in a specific cell-type in adult animals is methodologically challenging. Here we propose an approach to specifically assess mROS abundance in astrocytes that combines i) a targeting strategy based on the use of adeno-associated virus (AAV) vectors expressing the green fluorescent protein (GFP) under an astrocyte (glial fibrillary acidic protein or GFAP) promoter, along with, ii) a robust and widely extended protocol for the measurement of mROS by flow cytometry using commercial probes. The significance of this work is that it allows the selective study of astrocytic mROS abundance by means of easily accessible technology.
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- 2020
141. Mechanistic characterization of the thioredoxin system in the removal of hydrogen peroxide.
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Pannala, Venkat R. and Dash, Ranjan K.
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THIOREDOXIN reductase (NADPH) , *HYDROGEN peroxide , *CHEMICAL reduction , *THERMODYNAMICS , *CHEMICAL kinetics - Abstract
The thioredoxin system, which consists of a family of proteins, including thioredoxin (Trx), peroxiredoxin (Prx), and thioredoxin reductase (TrxR), plays a critical role in the defense against oxidative stress by removing harmful hydrogen peroxide (H 2 O 2 ). Specifically, Trx donates electrons to Prx to remove H 2 O 2 and then TrxR maintains the reduced Trx concentration with NADPH as the cofactor. Despite a great deal of kinetic information gathered on the removal of H 2 O 2 by the Trx system from various sources/species, a mechanistic understanding of the associated enzymes is still not available. We address this issue by developing a thermodynamically consistent mathematical model of the Trx system which entails mechanistic details and provides quantitative insights into the kinetics of the TrxR and Prx enzymes. Consistent with experimental studies, the model analyses of the available data show that both enzymes operate by a ping-pong mechanism. The proposed mechanism for TrxR, which incorporates substrate inhibition by NADPH and intermediate protonation states, well describes the available data and accurately predicts the bell-shaped behavior of the effect of pH on the TrxR activity. Most importantly, the model also predicts the inhibitory effects of the reaction products (NADP + and Trx(SH) 2 ) on the TrxR activity for which suitable experimental data are not available. The model analyses of the available data on the kinetics of Prx from mammalian sources reveal that Prx operates at very low H 2 O 2 concentrations compared to their human parasite counterparts. Furthermore, the model is able to predict the dynamic overoxidation of Prx at high H 2 O 2 concentrations, consistent with the available data. The integrated Prx–TrxR model simulations well describe the NADPH and H 2 O 2 degradation dynamics and also show that the coupling of TrxR- and Prx-dependent reduction of H 2 O 2 allowed ultrasensitive changes in the Trx concentration in response to changes in the TrxR concentration at high Prx concentrations. Thus, the model of this sort is very useful for integration into computational H 2 O 2 degradation models to identify its role in physiological and pathophysiological functions. [ABSTRACT FROM AUTHOR]
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- 2015
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142. The Chaperone Activity of Clusterin is Dependent on Glycosylation and Redox Environment.
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Rohne, Philipp, Prochnow, Hans, Wolf, Steven, Renner, Benjamin, and Koch-Brandt, Claudia
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MOLECULAR chaperones , *CLUSTERIN , *GLYCOSYLATION , *APOLIPOPROTEIN J , *PATHOLOGICAL physiology , *OXIDATION-reduction reaction - Abstract
Background/Aims: Clusterin (CLU), also known as Apolipoprotein J (ApoJ) is a highly glycosylated extracellular chaperone. In humans it is expressed from a broad spectrum of tissues and related to a plethora of physiological and pathophysiological processes, such as Alzheimer's disease, atherosclerosis and cancer. In its dominant form it is expressed as a secretory protein (secreted CLU, sCLU). During its maturation, the sCLU-precursor is N-glycosylated and cleaved into an α- and a β-chain, which are connected by five symmetrical disulfide bonds. Recently, it has been demonstrated that besides the predominant sCLU, rare intracellular CLU forms are expressed in stressed cells. Since these forms do not enter or complete the secretory pathway, they are not proteolytically modified and show either no or only core glycosylation. Due to their sparsity, these intracellular forms are functionally poorly characterized. To evaluate the function(s) of these stress-related intracellular forms, we investigate for the first time the impact of proteolytic cleavage, differential glycosylation and the influence of the redox environment on the chaperone activity of CLU. Methods: Non-cleavable sCLU was generated by expression from a mutant construct of sCLU, in which the furin-like proprotein convertase (PC) recognition site was modified. After purification of recombinant uncleaved sCLU from the medium of over-expressing cells, we performed chaperone activity assays to compare the activities of wild-type (cleaved) and uncleaved mutant sCLU. Additionally, this approach enabled us to investigate the role of carbohydrates, the proteolytic maturation and reducing conditions on CLU chaperone activity. Further, we characterized the differentially treated CLU forms by using MALDI-TOF, CD-spectroscopy and Western blotting in addition to the functional assay. Results: We show that the PC-cleavage is dispensable for sCLU chaperone activity. Moreover, our data demonstrate that while fully deglycosylated sCLU lacks chaperone activity, partially deglycosylated sCLU is still capable of solubilizing target proteins. Most importantly, we here demonstrate for the first time that uncleaved sCLU is highly sensitive towards reducing conditions. Conclusions: Our study provides evidence that unglycosylated intracellular CLU forms cannot exhibit a chaperone activity compared to sCLU. Additionally, we support recent postulates that glycosylated intracellular CLU forms may act as a redox sensor under oxidative stress conditions. Furthermore, we conclude that the proteolytic cleavage of sCLU is important to maintain full chaperone activity, i.e. in the presence of necrosis. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2014
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143. Hypochlorite Stress Assay for Phenotypic Analysis of the Halophilic Archaeon Haloferax volcanii Using an Improved Incubation Method and Growth Monitoring.
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Mondragon P, Hwang S, Schmid A, and Maupin-Furlow JA
- Abstract
The study of haloarchaea provides an opportunity to expand understanding of the mechanisms used by extremophiles to thrive in and respond to harsh environments, including hypersaline and oxidative stress conditions. A common strategy used to investigate molecular mechanisms of stress response involves the deletion and/or site-directed mutagenesis of genes identified through omics studies followed by a comparison of the mutant and wild-type strains for phenotypic differences. The experimental methods used to monitor these differences must be controlled and reproducible. Current methods to examine recovery of halophilic archaea from extreme stress are complicated by extended incubation times, nutrients not typically encountered in the environment, and other related limitations. Here we describe a method for assessing the function of genes during hypochlorite stress in the halophilic archaeon Haloferax volcanii that overcomes these types of limitations. The method was found reproducible and informative in identifying genes needed for H. volcanii to recover from hypochlorite stress., Competing Interests: Competing interests The Authors declare that there are no conflicts of interest., (Copyright © 2022 The Authors; exclusive licensee Bio-protocol LLC.)
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- 2022
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144. Plasma membrane anchored nanosensor for quantifying endogenous production of H2O2 in living cells
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Ayumi Sumino, Yoshinori Marunaka, Leonardo Puppulin, Shigekuni Hosogi, Eishi Ashihara, Hideo Tanaka, and Tadaaki Yamada
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inorganic chemicals ,Cell signaling ,Cell ,Biomedical Engineering ,Biophysics ,Nanosensor ,02 engineering and technology ,4-Mercaptophenylboronic pinacol ester ,Gold nanoparticles ,Hydrogen peroxide ,NADPH-Oxidase ,Redox biology ,Surface enhanced Raman spectroscopy ,01 natural sciences ,Electrochemistry ,medicine ,Extracellular ,Settore CHIM/02 - Chimica Fisica ,Cell growth ,010401 analytical chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Cytosol ,medicine.anatomical_structure ,Second messenger system ,Signal transduction ,0210 nano-technology ,Intracellular ,Biotechnology - Abstract
Hydrogen peroxide (H2O2) is one of the main second messengers involved in signaling pathways controlling cell metabolism. During tumorigenesis H2O2 is generated on the extracellular space by membrane-associated NADPH oxidases and superoxide dismutase to stimulate cell proliferation and preservation of the transformed state. Accordingly, a characteristic feature of malignant cells is overproduction of H2O2 in the extracellular milieu and the subsequent absorption in the cytosol. Since the most significant gradients of endogenous extracellular H2O2 can be observed only in a very shallow region of the fluid in contact with the plasma membrane, we show here the use of a newly designed nanosensor anchored to the outer cell surface and capable of quantifying H2O2 at nanometer distance from the membrane proteins responsible for its production. This biosensor is built upon gold nanoparticles functionalized with a H2O2-sensitive boronate compound that is probed using surface enhanced Raman spectroscopy (SERS). The highly localized information obtained on the cell surface by SERS analysis is combined with analytical methods of redox biology to estimate the associated levels of intracellular H2O2 responsible for cell signaling. The results obtained from A549 lung cancer cell line show localized spots on the cell surface at concentration up to 12 μM, associated to intracellular concentration up to 5.1 nM.
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- 2021
145. Ebselen, a promising antioxidant drug: mechanisms of action and targets of biological pathways.
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Azad, Gajendra and Tomar, Raghuvir
- Abstract
Ebselen, an organoselenium compound, mimics glutathione peroxidase activity. It is a multifunctional compound, which catalyzes several essential reactions for the protection of cellular components from oxidative and free radical damage. Based on a number of in vitro and in vivo studies, various mechanisms are proposed to understand the biomedical actions of ebselen in health and diseases. It modulates metallo-proteins, enzymatic cofactors, gene expression, epigenetics, antioxidant defenses and immune systems. Owing to these properties, ebselen is currently under clinical trials for the prevention and treatment of various disorders such as cardiovascular diseases, arthritis, stroke, atherosclerosis, and cancer. A few ebselen-based pharmaceutical agents are under extensive investigation. As ebselen has been shown to have significant cellular toxicity, appropriate studies are needed to redesign the ebselen-based therapy for clinical trials. This review summarizes current understanding of the biochemical and molecular properties, and pharmacological applications of ebselen and future directions in this area of research. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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146. A mechanistic mathematical model for the catalytic action of glutathione peroxidase.
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Pannala, V. R., Bazil, J. N., Camara, A. K. S., and Dash, R. K.
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MATHEMATICAL models , *GLUTATHIONE peroxidase , *ENZYME kinetics , *OXIDATIVE stress , *LIPID peroxidation (Biology) , *PATHOLOGICAL physiology - Abstract
Glutathione peroxidase (GPx) is a well-known seleno-enzyme that protects cells from oxidative stress (e.g., lipid peroxidation and oxidation of other cellular proteins and macromolecules), by catalyzing the reduction of harmful peroxides (e.g., hydrogen peroxide: H2O2) with reduced glutathione (GSH). However, the catalytic mechanism of GPx kinetics is not well characterized in terms of a mathematical model. We developed here a mechanistic mathematical model of GPx kinetics by considering a unified catalytic scheme and estimated the unknown model parameters based on different experimental data from the literature on the kinetics of the enzyme. The model predictions are consistent with the consensus that GPx operates via a ping-pong mechanism. The unified catalytic scheme proposed here for GPx kinetics clarifies various anomalies, such as what are the individual steps in the catalytic scheme by estimating their associated rate constant values and a plausible rationale for the contradicting experimental results. The developed model presents a unique opportunity to understand the effects of pH and product GSSG on the GPx activity under both physiological and pathophysiological conditions. Although model parameters related to the product GSSG were not identifiable due to lack of product-inhibition data, the preliminary model simulations with the assumed range of parameters show that the inhibition by the product GSSG is negligible, consistent with what is known in the literature. In addition, the model is able to simulate the bi-modal behavior of the GPx activity with respect to pH with the pH-range for maximal GPx activity decreasing significantly as the GSH levels decrease and H2O2 levels increase (characteristics of oxidative stress). The model provides a key component for an integrated model of H2O2 balance under normal and oxidative stress conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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147. Inhibition of tumour cell growth by carnosine: some possible mechanisms.
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Hipkiss, Alan and Gaunitz, Frank
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- *
CANCER cell growth , *CARNOSINE , *NOOTROPIC agents , *GLYOXALASE , *APOPTOSIS , *GENE expression , *ADENOSINE triphosphate , *PREVENTION - Abstract
The naturally occurring dipeptide carnosine (β-alanyl- l-histidine) has been shown to inhibit, selectively, growth of transformed cells mediated, at least in part, by depleting glycolytic ATP levels. The mechanism(s) responsible has/have yet to be determined. Here, we discuss a number of probable and/or possible processes which could, theoretically, suppress glycolytic activity which would decrease ATP supply and generation of metabolic intermediates required for continued cell reproduction. Possibilities include effects on (i) glycolytic enzymes, (ii) metabolic regulatory activities, (iii) redox biology, (iv) protein glycation, (v) glyoxalase activity, (vi) apoptosis, (vii) gene expression and (viii) metastasis. It is possible, by acting at various sites that this pluripotent dipeptide may be an example of an endogenous 'smart drug'. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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148. In Vivo Imaging with Genetically Encoded Redox Biosensors
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Daria A. Kotova, Aleksandra D. Kokova, Dmitry S. Bilan, Alexander I. Kostyuk, Anastasiya S. Panova, Oleg V. Podgorny, Dmitry I Maltsev, and Vsevolod V. Belousov
- Subjects
fluorescent proteins ,Context (language use) ,Computational biology ,Biosensing Techniques ,Review ,Biology ,genetically encoded sensors ,reactive oxygen species (ROS) ,Redox ,Catalysis ,Inorganic Chemistry ,lcsh:Chemistry ,NADPH ,Animals ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,lcsh:QH301-705.5 ,redox biology ,Spectroscopy ,Organic Chemistry ,General Medicine ,Glutathione ,Computer Science Applications ,Molecular Imaging ,Luminescent Proteins ,lcsh:Biology (General) ,lcsh:QD1-999 ,mycothiol (MSH), NADH ,Reactive Oxygen Species ,Biosensor ,Oxidation-Reduction ,glutathione (GSH), hydrogen peroxide (H2O2), in vivo imaging - Abstract
Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.
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- 2020
149. Redox basis of exercise physiology
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Michalis G. Nikolaidis, Antonios Kyparos, Vassilis Paschalis, Anastasios A. Theodorou, and Nikos V. Margaritelis
- Subjects
0301 basic medicine ,Bioenergetics ,Glucose uptake ,Clinical Biochemistry ,Biochemistry ,Redox ,Article ,Antioxidants ,Muscle hypertrophy ,03 medical and health sciences ,0302 clinical medicine ,Humans ,Responses ,Exercise physiology ,Muscle, Skeletal ,Redox biology ,Exercise ,lcsh:QH301-705.5 ,chemistry.chemical_classification ,Reactive oxygen species ,Adaptations ,lcsh:R5-920 ,Organelle Biogenesis ,Redox homeostasis ,Organic Chemistry ,Adaptation, Physiological ,Signaling ,Cell biology ,030104 developmental biology ,chemistry ,Mitochondrial biogenesis ,lcsh:Biology (General) ,lcsh:Medicine (General) ,Oxidation-Reduction ,030217 neurology & neurosurgery ,Muscle Contraction - Abstract
Redox reactions control fundamental processes of human biology. Therefore, it is safe to assume that the responses and adaptations to exercise are, at least in part, mediated by redox reactions. In this review, we are trying to show that redox reactions are the basis of exercise physiology by outlining the redox signaling pathways that regulate four characteristic acute exercise-induced responses (muscle contractile function, glucose uptake, blood flow and bioenergetics) and four chronic exercise-induced adaptations (mitochondrial biogenesis, muscle hypertrophy, angiogenesis and redox homeostasis). Based on our analysis, we argue that redox regulation should be acknowledged as central to exercise physiology., Graphical abstract Image 1, Highlights • Redox reactions are a fundamental part of human biology. • Exercise responses and adaptations are partially controlled by redox reactions. • Redox signaling should be acknowledged as central to exercise physiology.
- Published
- 2020
150. Sexual dimorphism in glutathione metabolism and glutathione-dependent responses
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Yong-Joo Ahn, Luxi Wang, and Reto Asmis
- Subjects
0301 basic medicine ,Cell signaling ,Antioxidant ,Macrophage ,medicine.medical_treatment ,Clinical Biochemistry ,Biology ,Biochemistry ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Gene expression ,medicine ,Humans ,Obesity ,Redox biology ,lcsh:QH301-705.5 ,Sex Characteristics ,lcsh:R5-920 ,Cell growth ,Organic Chemistry ,Neurodegeneration ,Proteins ,Glutathione ,medicine.disease ,Atherosclerosis ,Cell biology ,Sexual dimorphism ,030104 developmental biology ,chemistry ,lcsh:Biology (General) ,lcsh:Medicine (General) ,Oxidation-Reduction ,030217 neurology & neurosurgery ,Intracellular ,Signal Transduction - Abstract
Glutathione is the most abundant intracellular low molecular weight thiol in cells and tissues, and plays an essential role in numerous cellular processes, including antioxidant defenses, the regulation of protein function, protein localization and stability, DNA synthesis, gene expression, cell proliferation, and cell signaling. Sexual dimorphisms in glutathione biology, metabolism and glutathione-dependent signaling have been reported for a broad range of biological processes, spanning the human lifespan from early development to aging. Sex-depended differences with regard to glutathione and its biology have also been reported for a number of human pathologies and diseases such as neurodegeneration, cardiovascular diseases and metabolic disorders. Here we review the latest literature in this field and discuss the potential impact of these sexual dimorphisms in glutathione biology on human health and diseases.
- Published
- 2020
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