scholarly journals Visualization of the Redox Status of Cytosolic Glutathione Using the Organelle- and Cytoskeleton-Targeted Redox Sensors

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 129
Author(s):  
Yuta Hatori ◽  
Takanori Kubo ◽  
Yuichiro Sato ◽  
Sachiye Inouye ◽  
Reiko Akagi ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Biological Membrane ◽  
Redox Homeostasis ◽  
Redox Balance ◽  
Redox Status ◽  
Golgi Body ◽  
Redox Equilibrium ◽  
Cytosolic Glutathione ◽  
Redox Sensors ◽  
Subcellular Resolution

Glutathione is a small thiol-containing peptide that plays a central role in maintaining cellular redox homeostasis. Glutathione serves as a physiologic redox buffer by providing thiol electrons for catabolizing harmful oxidants and reversing oxidative effects on biomolecules. Recent evidence suggests that the balance of reduced and oxidized glutathione (GSH/GSSG) defines the redox states of Cys residues in proteins and fine-tunes their stabilities and functions. To elucidate the redox balance of cellular glutathione at subcellular resolution, a number of redox-sensitive green fluorescent protein (roGFP) variants have been developed. In this study, we constructed and functionally validated organelle- and cytoskeleton-targeted roGFP and elucidated the redox status of the cytosolic glutathione at a subcellular resolution. These new redox sensors firmly established a highly reduced redox equilibrium of cytosolic glutathione, wherein significant deviation was observed among cells. By targeting the sensor to the cytosolic and lumen sides of the Golgi membrane, we identified a prominent redox gradient across the biological membrane at the Golgi body. The results demonstrated that organelle- and cytoskeleton-targeted sensors enable the assessment of glutathione oxidation near the cytosolic surfaces of different organelle membranes.

scholarly journals Monitoring disulfide bond formation in the eukaryotic cytosol

2004 ◽  
Vol 166 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Henrik Østergaard ◽  
Christine Tachibana ◽  
Jakob R. Winther
Keyword(s):  
Fluorescent Protein ◽  
Redox Status ◽  
Reduced And Oxidized Glutathione ◽  
Cytosolic Glutathione ◽  
Green Fluorescent ◽  
Genetically Manipulated ◽  
First Time ◽  
Glutathione Redox

Glutathione is the most abundant low molecular weight thiol in the eukaryotic cytosol. The compartment-specific ratio and absolute concentrations of reduced and oxidized glutathione (GSH and GSSG, respectively) are, however, not easily determined. Here, we present a glutathione-specific green fluorescent protein–based redox probe termed redox sensitive YFP (rxYFP). Using yeast with genetically manipulated GSSG levels, we find that rxYFP equilibrates with the cytosolic glutathione redox buffer. Furthermore, in vivo and in vitro data show the equilibration to be catalyzed by glutaredoxins and that conditions of high intracellular GSSG confer to these a new role as dithiol oxidases. For the first time a genetically encoded probe is used to determine the redox potential specifically of cytosolic glutathione. We find it to be −289 mV, indicating that the glutathione redox status is highly reducing and corresponds to a cytosolic GSSG level in the low micromolar range. Even under these conditions a significant fraction of rxYFP is oxidized.

scholarly journals Intraperoxisomal redox balance in mammalian cells: oxidative stress and interorganellar cross-talk

2011 ◽  
Vol 22 (9) ◽  
pp. 1440-1451 ◽  
Author(s):  
Oksana Ivashchenko ◽  
Paul P. Van Veldhoven ◽  
Chantal Brees ◽  
Ye-Shih Ho ◽  
Stanley R. Terlecky ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intracellular Signaling ◽  
Mammalian Cells ◽  
Fluorescent Protein ◽  
Redox Balance ◽  
Growth Conditions ◽  
Redox Status ◽  
Cellular Aging ◽  
Ros Generation ◽  
Age Related

Reactive oxygen species (ROS) are at once unsought by-products of metabolism and critical regulators of multiple intracellular signaling cascades. In nonphotosynthetic eukaryotic cells, mitochondria are well-investigated major sites of ROS generation and related signal initiation. Peroxisomes are also capable of ROS generation, but their contribution to cellular oxidation–reduction (redox) balance and signaling events are far less well understood. In this study, we use a redox-sensitive variant of enhanced green fluorescent protein (roGFP2-PTS1) to monitor the state of the peroxisomal matrix in mammalian cells. We show that intraperoxisomal redox status is strongly influenced by environmental growth conditions. Furthermore, disturbances in peroxisomal redox balance, although not necessarily correlated with the age of the organelle, may trigger its degradation. We also demonstrate that the mitochondrial redox balance is perturbed in catalase-deficient cells and upon generation of excess ROS inside peroxisomes. Peroxisomes are found to resist oxidative stress generated elsewhere in the cell but are affected when the burden originates within the organelle. These results suggest a potential broader role for the peroxisome in cellular aging and the initiation of age-related degenerative disease.

Proteasome Inhibitors in Cancer Therapy and their Relation to Redox Regulation

2019 ◽  
Vol 24 (44) ◽  
pp. 5252-5267
Author(s):  
Gulce Sari ◽  
Zehra Okat ◽  
Ali Sahin ◽  
Betul Karademir
Keyword(s):  
Signaling Pathways ◽  
Redox Regulation ◽  
Molecular Mechanisms ◽  
Redox Homeostasis ◽  
Proteasome Inhibitors ◽  
Redox System ◽  
Redox Balance ◽  
Redox Status ◽  
Signaling Molecules ◽  
Cancer Therapies

Redox homeostasis is important for the maintenance of cell survival. Under physiological conditions, redox system works in a balance and involves activation of many signaling molecules. Regulation of redox balance via signaling molecules is achieved by different pathways and proteasomal system is a key pathway in this process. Importance of proteasomal system on signaling pathways has been investigated for many years. In this direction, many proteasome targeting molecules have been developed. Some of them are already in the clinic for cancer treatment and some are still under investigation to highlight underlying mechanisms. Although there are many studies done, molecular mechanisms of proteasome inhibitors and related signaling pathways need more detailed explanations. This review aims to discuss redox status and proteasomal system related signaling pathways. In addition, cancer therapies targeting proteasomal system and their effects on redox-related pathways have been summarized.

scholarly journals Alterations in glutathione redox homeostasis among adolescents with obesity and anemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalal Alkazemi ◽  
Abdur Rahman ◽  
Banan Habra
Keyword(s):  
Defense Mechanism ◽  
Dynamic Balance ◽  
Redox Homeostasis ◽  
Redox Status ◽  
Cross Sectional Study ◽  
Normal Weight ◽  
Overweight And Obesity ◽  
Metabolic Disturbances ◽  
Cross Sectional ◽  
Gpx Activity

AbstractThe reduced (GSH)-to-oxidized (GSSG) glutathione ratio represents a dynamic balance between oxidants and antioxidants. However, redox status in adolescents with obesity and anemia has not been investigated. This study investigated the association of erythrocyte GSH redox status (GSH, GSH:GSSG ratio, and glutathione peroxidase [GPx] activity) with anemia and adiposity in adolescents. This case–control study nested in a cross-sectional study enrolled 524 adolescents (268 boys; 256 girls). The prevalence of anemia in overweight and obesity (OWOB) was 5.2% in boys and 11.7% in girls. The GSH:GSSG ratio and GPx activity were significantly higher in girls than in boys (p < 0.001), in anemic than in non-anemic subjects (p < 0.001), and in OWOB than in normal-weight subjects (p < 0.001). Similarly, significantly higher GSH: GSSG level (p < 0.001) and GPx activity (p < 0.001) were found in subjects with 90th percentile waist circumference than in those with < 90th percentile. GPx and GSH:GSSG were positively associated with anemia after adjusting for age, sex, and body mass index (adjusted odds ratio, adjOR [95% confidence interval, CI] 2.18 [1.44–3.29]) or tertiles (adjOR [95% CI], T3 = 2.49 [1.03–6.01]). A similar association was noted for GSH and GPx. A compensatory increased redox defense mechanism exists in anemia and obesity among adolescents without metabolic disturbances.

scholarly journals Oxidative status in dairy goats: periparturient variation and changes in subclinical hyperketonemia and hypocalcemia

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Yan Huang ◽  
Jing Wen ◽  
Yezi Kong ◽  
Chenxu Zhao ◽  
Siqi Liu ◽  
...  
Keyword(s):  
Milk Yield ◽  
Redox Homeostasis ◽  
Redox Status ◽  
Oxidative Status ◽  
The Body ◽  
Production Performance ◽  
Lactation Period ◽  
Dairy Goats ◽  
Periparturient Period ◽  
Total Antioxidant

Abstract Background A better comprehension of the redox status during the periparturient period may facilitate the development of management and nutritional solutions to prevent subclinical hyperketonemia (SCHK) and subclinical hypocalcemia (SCHC) in dairy goats. We aimed to evaluate the variation in the redox status of dairy goats with SCHK and SCHC during their periparturient periods. Guanzhong dairy goats (n = 30) were assigned to SCHK (n = 10), SCHC (n = 10), and healthy (HEAL, n = 10) groups based on their blood β-hydroxybutyrate (BHBA) and calcium (Ca) concentrations. Blood were withdrawn from goats every week from 3 weeks before the expected parturition date to 3 weeks post-kidding. On the same day, the body condition scores (BCS) were evaluated, and the milk yield was recorded for each goat. The metabolic profile parameters and the indicators of oxidative status were determined by using the standard biochemical techniques. Results In comparison with the HEAL goats, SCHK and SCHC goats presented with a more dramatic decline of BCS post-kidding and a significant decrease in the milk yield at 2- and 3-weeks postpartum, ignoring the obvious increase at 1-week postpartum. The levels of non-esterified fatty acids (NEFA) peaked at parturition, exhibiting significantly higher levels from 1-week prepartum to the parturition day in the SCHK and SCHC groups. The malondialdehyde (MDA) concentration was increased in the SCHK goats from 1-week antepartum until 3-weeks postpartum, with its concentration being significantly higher in the SCHC goats at parturition. The hydrogen peroxide (H2O2) concentration was significantly lower in the SCHK and SCHC goats from 2-weeks antepartum to 1-week post-kidding. The total antioxidant capacity (T-AOC) and the superoxide dismutase (SOD) level were decreased at 1-week antepartum in the SCHK and SCHC goats, respectively. The glutathione peroxidase (GSH-Px) level was increased in the SCHK and SCHC goats during the early lactation period. Conclusions The SCHK and SCHC goats exerted more efforts to maintain their redox homeostasis and to ensure the production performance than the HEAL goats during their periparturient period, probably owing to more intense fat mobilization and lipid peroxidation in the former.

Effects of iron-related compounds and bilirubin on redox homeostasis in endometriosis and its malignant transformations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroshi Shigetomi ◽  
Shogo Imanaka ◽  
Hiroshi Kobayashi
Keyword(s):  
Oxidative Stress ◽  
Redox Homeostasis ◽  
Redox Balance ◽  
Heme Iron ◽  
Total Iron ◽  
University Hospital ◽  
Free Iron ◽  
Significant Difference ◽  
Iron Heme ◽  
Related Compounds

Abstract Objectives The balance between oxidative stress and antioxidant defense has been reported to differ between women with endometriosis and patients with its malignant transformation. The aim of this study is to investigate changes in redox balance in endometriosis and endometriosis-related ovarian cancer (EAOC) by simultaneously measuring iron-related compounds and bilirubin. Methods This study included 235 patients with a histopathologically confirmed diagnosis of endometriosis (n=178) and EAOC (n=57). Cyst fluid samples were collected in Nara Medical University hospital from January 2013 to May 2019. The levels of iron-related compounds (total iron, heme iron, free iron, oxyhemoglobin [oxyHb], methemoglobin [metHb], and metHb/oxyHb ratio) and bilirubin were measured. Results Total iron, heme iron, free iron, metHb/oxyHb ratio, and bilirubin were significantly elevated in endometriosis compared to EAOC. In both endometriosis and EAOC, iron-related compounds in the cyst were correlated with each other. There was no statistically significant difference in oxyHb and metHb levels between the two groups, but the metHb/oxyHb ratio was significantly higher in endometriosis than in EAOC. Bilirubin was positively correlated with total iron and free iron in EAOC, but there was no correlation between bilirubin and iron-related compounds in endometriosis. Conclusions Iron-induced oxidative stress in endometriosis may exceed bilirubin-dependent antioxidant capability, while redox homeostasis in EAOC can be maintained by at least bilirubin.

scholarly journals Saturated Fatty Acid Activates T Cell Inflammation Through a Nicotinamide Nucleotide Transhydrogenase (NNT)-Dependent Mechanism

Biomolecules ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 79 ◽  
Author(s):  
Grace McCambridge ◽  
Madhur Agrawal ◽  
Alanna Keady ◽  
Philip Kern ◽  
Hatice Hasturk ◽  
...  
Keyword(s):  
Fatty Acids ◽  
T Cell ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Redox Homeostasis ◽  
Mitochondrial Protein ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Redox Balance ◽  
Specific Stimulus ◽  
Nicotinamide Nucleotide Transhydrogenase

Circulating fatty acids (FAs) increase with obesity and can drive mitochondrial damage and inflammation. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial protein that positively regulates nicotinamide adenine dinucleotide phosphate (NADPH), a key mediator of energy transduction and redox homeostasis. The role that NNT-regulated bioenergetics play in the inflammatory response of immune cells in obesity is untested. Our objective was to determine how free fatty acids (FFAs) regulate inflammation through impacts on mitochondria and redox homeostasis of peripheral blood mononuclear cells (PBMCs). PBMCs from lean subjects were activated with a T cell-specific stimulus in the presence or absence of generally pro-inflammatory palmitate and/or non-inflammatory oleate. Palmitate decreased immune cell expression of NNT, NADPH, and anti-oxidant glutathione, but increased reactive oxygen and proinflammatory Th17 cytokines. Oleate had no effect on these outcomes. Genetic inhibition of NNT recapitulated the effects of palmitate. PBMCs from obese (BMI >30) compared to lean subjects had lower NNT and glutathione expression, and higher Th17 cytokine expression, none of which were changed by exogenous palmitate. Our data identify NNT as a palmitate-regulated rheostat of redox balance that regulates immune cell function in obesity and suggest that dietary or therapeutic strategies aimed at increasing NNT expression may restore redox balance to ameliorate obesity-associated inflammation.

scholarly journals Exploring the Use of Dimethyl Fumarate as Microglia Modulator for Neurodegenerative Diseases Treatment

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 700
Author(s):  
Maria Rosito ◽  
Claudia Testi ◽  
Giacomo Parisi ◽  
Barbara Cortese ◽  
Paola Baiocco ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Iron Homeostasis ◽  
Brain Injuries ◽  
Neuroprotective Effect ◽  
Redox Homeostasis ◽  
Dimethyl Fumarate ◽  
Redox Balance ◽  
Fumaric Acid Ester ◽  
The Central Nervous System

The maintenance of redox homeostasis in the brain is critical for the prevention of the development of neurodegenerative diseases. Drugs acting on brain redox balance can be promising for the treatment of neurodegeneration. For more than four decades, dimethyl fumarate (DMF) and other derivatives of fumaric acid ester compounds have been shown to mitigate a number of pathological mechanisms associated with psoriasis and relapsing forms of multiple sclerosis (MS). Recently, DMF has been shown to exert a neuroprotective effect on the central nervous system (CNS), possibly through the modulation of microglia detrimental actions, observed also in multiple brain injuries. In addition to the hypothesis that DMF is linked to the activation of NRF2 and NF-kB transcription factors, the neuroprotective action of DMF may be mediated by the activation of the glutathione (GSH) antioxidant pathway and the regulation of brain iron homeostasis. This review will focus on the role of DMF as an antioxidant modulator in microglia processes and on its mechanisms of action in the modulation of different pathways to attenuate neurodegenerative disease progression.

scholarly journals Linkage between Carbon Metabolism, Redox Status and Cellular Physiology in the Yeast Saccharomyces cerevisiae Devoid of SOD1 or SOD2 Gene

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 780 ◽  
Author(s):  
Roman Maslanka ◽  
Renata Zadrag-Tecza ◽  
Magdalena Kwolek-Mirek
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Metabolism ◽  
Redox Homeostasis ◽  
Carbon Sources ◽  
Pyridine Nucleotide ◽  
Redox Status ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cellular Physiology ◽  
Respiratory Conditions

Saccharomyces cerevisiae yeast cells may generate energy both by fermentation and aerobic respiration, which are dependent on the type and availability of carbon sources. Cells adapt to changes in nutrient availability, which entails the specific costs and benefits of different types of metabolism but also may cause alteration in redox homeostasis, both by changes in reactive oxygen species (ROS) and in cellular reductant molecules contents. In this study, yeast cells devoid of the SOD1 or SOD2 gene and fermentative or respiratory conditions were used to unravel the connection between the type of metabolism and redox status of cells and also how this affects selected parameters of cellular physiology. The performed analysis provides an argument that the source of ROS depends on the type of metabolism and non-mitochondrial sources are an important pool of ROS in yeast cells, especially under fermentative metabolism. There is a strict interconnection between carbon metabolism and redox status, which in turn has an influence on the physiological efficiency of the cells. Furthermore, pyridine nucleotide cofactors play an important role in these relationships.

scholarly journals Differential regulation of Ca2+ influx by ORAI channels mediates enamel mineralization

2019 ◽  
Vol 12 (578) ◽  
pp. eaav4663 ◽  
Author(s):  
Miriam Eckstein ◽  
Martin Vaeth ◽  
Francisco J. Aulestia ◽  
Veronica Costiniti ◽  
Serena N. Kassam ◽  
...  
Keyword(s):  
Consumption Rate ◽  
Redox Homeostasis ◽  
Direct Interaction ◽  
Redox Status ◽  
Cellular Functions ◽  
Enamel Defects ◽  
Targeted Deletion ◽  
Anhidrotic Ectodermal Dysplasia ◽  
Enamel Mineralization

Store-operated Ca2+ entry (SOCE) channels are highly selective Ca2+ channels activated by the endoplasmic reticulum (ER) sensors STIM1 and STIM2. Their direct interaction with the pore-forming plasma membrane ORAI proteins (ORAI1, ORAI2, and ORAI3) leads to sustained Ca2+ fluxes that are critical for many cellular functions. Mutations in the human ORAI1 gene result in immunodeficiency, anhidrotic ectodermal dysplasia, and enamel defects. In our investigation of the role of ORAI proteins in enamel, we identified enamel defects in a patient with an ORAI1 null mutation. Targeted deletion of the Orai1 gene in mice showed enamel defects and reduced SOCE in isolated enamel cells. However, Orai2−/− mice showed normal enamel despite having increased SOCE in the enamel cells. Knockdown experiments in the enamel cell line LS8 suggested that ORAI2 and ORAI3 modulated ORAI1 function, with ORAI1 and ORAI2 being the main contributors to SOCE. ORAI1-deficient LS8 cells showed altered mitochondrial respiration with increased oxygen consumption rate and ATP, which was associated with altered redox status and enhanced ER Ca2+ uptake, likely due to S-glutathionylation of SERCA pumps. Our findings demonstrate an important role of ORAI1 in Ca2+ influx in enamel cells and establish a link between SOCE, mitochondrial function, and redox homeostasis.

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