Journal articles on the topic 'Oxidative state of protein'
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1
Garavaglia, Maria Lisa, Daniela Giustarini, Graziano Colombo, Francesco Reggiani, Silvia Finazzi, Marta Calatroni, Lucia Landoni, et al. "Blood Thiol Redox State in Chronic Kidney Disease." International Journal of Molecular Sciences 23, no. 5 (March 5, 2022): 2853. http://dx.doi.org/10.3390/ijms23052853.
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Thiols (sulfhydryl groups) are effective antioxidants that can preserve the correct structure of proteins, and can protect cells and tissues from damage induced by oxidative stress. Abnormal levels of thiols have been measured in the blood of patients with moderate-to-severe chronic kidney disease (CKD) compared to healthy subjects, as well as in end-stage renal disease (ESRD) patients on haemodialysis or peritoneal dialysis. The levels of protein thiols (a measure of the endogenous antioxidant capacity inversely related to protein oxidation) and S-thiolated proteins (mixed disulphides of protein thiols and low molecular mass thiols), and the protein thiolation index (the molar ratio of the S-thiolated proteins to free protein thiols in plasma) have been investigated in the plasma or red blood cells of CKD and ESRD patients as possible biomarkers of oxidative stress. This type of minimally invasive analysis provides valuable information on the redox status of the less-easily accessible tissues and organs, and of the whole organism. This review provides an overview of reversible modifications in protein thiols in the setting of CKD and renal replacement therapy. The evidence suggests that protein thiols, S-thiolated proteins, and the protein thiolation index are promising biomarkers of reversible oxidative stress that could be included in the routine monitoring of CKD and ESRD patients.
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Friguet, Bertrand. "Protein Repair and Degradation during Aging." Scientific World JOURNAL 2 (2002): 248–54. http://dx.doi.org/10.1100/tsw.2002.98.
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Cellular aging is characterized by a build-up of oxidatively modified proteins. The steady-state level of oxidized proteins depends on the balance between the rate of protein oxidative damage and the rates of protein degradation and repair. Therefore, the accumulation of oxidized protein with age can be due to increased protein damage, decreased oxidized protein degradation and repair, or the combination of both mechanisms. The proteasomal system is the major intracellular proteolytic pathway implicated in the degradation of oxidized protein, and the peptide methionine sulfoxide reductase catalyzes the reduction of methionine sulfoxide (i.e., oxidized methionine) to methionine within proteins. A short summary on protein oxidative damage and oxidized protein degradation is given, and evidence for a decline of proteasome function with age is presented. Arguments for the implication of peptide methionine sulfoxide reductase in the age-related accumulation of oxidized protein are also discussed.
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Moilanen, Antti, and Lloyd W. Ruddock. "Non-native proteins inhibit the ER oxidoreductin 1 (Ero1)–protein disulfide-isomerase relay when protein folding capacity is exceeded." Journal of Biological Chemistry 295, no. 26 (February 26, 2020): 8647–55. http://dx.doi.org/10.1074/jbc.ra119.011766.
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Protein maturation in the endoplasmic reticulum (ER) depends on a fine balance between oxidative protein folding and quality control mechanisms, which together ensure high-capacity export of properly folded proteins from the ER. Oxidative protein folding needs to be regulated to avoid hyperoxidation. The folding capacity of the ER is regulated by the unfolded protein response (UPR) and ER-associated degradation (ERAD). The UPR is triggered by unfolded protein stress and leads to up-regulation of cellular components such as chaperones and folding catalysts. These components relieve stress by increasing folding capacity and up-regulating ERAD components that remove non-native proteins. Although oxidative protein folding and the UPR/ERAD pathways each are well-understood, very little is known about any direct cross-talk between them. In this study, we carried out comprehensive in vitro activity and binding assays, indicating that the oxidative protein folding relay formed by ER oxidoreductin 1 (Ero1), and protein disulfide-isomerase can be inactivated by a feedback inhibition mechanism involving unfolded proteins and folding intermediates when their levels exceed the folding capacity of the system. This mechanism allows client proteins to remain mainly in the reduced state and thereby minimizes potential futile oxidation–reduction cycles and may also enhance ERAD, which requires reduced protein substrates. Relief from excess levels of non-native proteins by increasing the levels of folding factors removed the feedback inhibition. These results reveal regulatory cross-talk between the oxidative protein folding and UPR and ERAD pathways.
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Ghezzi, P. "Oxidoreduction of protein thiols in redox regulation." Biochemical Society Transactions 33, no. 6 (October 26, 2005): 1378–81. http://dx.doi.org/10.1042/bst0331378.
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Protein cysteines can undergo various forms of oxidation, some of them reversible (disulphide formation, glutathionylation and S-nitrosylation). While in the past these were viewed as protein damage in the context of oxidative stress, there is growing interest in oxidoreduction of protein thiols/disulphides as a regulatory mechanism. This review discusses the evolution of the concept of redox regulation from that of oxidative stress and the redox state of protein cysteines in different cellular compartments.
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Tomin, Tamara, Matthias Schittmayer, Simon Sedej, Heiko Bugger, Johannes Gollmer, Sophie Honeder, Barbara Darnhofer, et al. "Mass Spectrometry-Based Redox and Protein Profiling of Failing Human Hearts." International Journal of Molecular Sciences 22, no. 4 (February 11, 2021): 1787. http://dx.doi.org/10.3390/ijms22041787.
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Oxidative stress contributes to detrimental functional decline of the myocardium, leading to the impairment of the antioxidative defense, dysregulation of redox signaling, and protein damage. In order to precisely dissect the changes of the myocardial redox state correlated with oxidative stress and heart failure, we subjected left-ventricular tissue specimens collected from control or failing human hearts to comprehensive mass spectrometry-based redox and quantitative proteomics, as well as glutathione status analyses. As a result, we report that failing hearts have lower glutathione to glutathione disulfide ratios and increased oxidation of a number of different proteins, including constituents of the contractile machinery as well as glycolytic enzymes. Furthermore, quantitative proteomics of failing hearts revealed a higher abundance of proteins responsible for extracellular matrix remodeling and reduced abundance of several ion transporters, corroborating contractile impairment. Similar effects were recapitulated by an in vitro cell culture model under a controlled oxygen atmosphere. Together, this study provides to our knowledge the most comprehensive report integrating analyses of protein abundance and global and peptide-level redox state in end-stage failing human hearts as well as oxygen-dependent redox and global proteome profiles of cultured human cardiomyocytes.
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Christians, Elisabeth S., and Ivor J. Benjamin. "Proteostasis and REDOX state in the heart." American Journal of Physiology-Heart and Circulatory Physiology 302, no. 1 (January 2012): H24—H37. http://dx.doi.org/10.1152/ajpheart.00903.2011.
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Force-generating contractile cells of the myocardium must achieve and maintain their primary function as an efficient mechanical pump over the life span of the organism. Because only half of the cardiomyocytes can be replaced during the entire human life span, the maintenance strategy elicited by cardiac cells relies on uninterrupted renewal of their components, including proteins whose specialized functions constitute this complex and sophisticated contractile apparatus. Thus cardiac proteins are continuously synthesized and degraded to ensure proteome homeostasis, also termed “proteostasis.” Once synthesized, proteins undergo additional folding, posttranslational modifications, and trafficking and/or become involved in protein-protein or protein-DNA interactions to exert their functions. This includes key transient interactions of cardiac proteins with molecular chaperones, which assist with quality control at multiple levels to prevent misfolding or to facilitate degradation. Importantly, cardiac proteome maintenance depends on the cellular environment and, in particular, the reduction-oxidation (REDOX) state, which is significantly different among cardiac organelles (e.g., mitochondria and endoplasmic reticulum). Taking into account the high metabolic activity for oxygen consumption and ATP production by mitochondria, it is a challenge for cardiac cells to maintain the REDOX state while preventing either excessive oxidative or reductive stress. A perturbed REDOX environment can affect protein handling and conformation (e.g., disulfide bonds), disrupt key structure-function relationships, and trigger a pathogenic cascade of protein aggregation, decreased cell survival, and increased organ dysfunction. This review covers current knowledge regarding the general domain of REDOX state and protein folding, specifically in cardiomyocytes under normal-healthy conditions and during disease states associated with morbidity and mortality in humans.
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Iossa, S., G. Liverini, and A. Barletta. "Effect of thyroid state and cold exposure on rat liver mitochondrial protein mass and function." Journal of Endocrinology 131, no. 1 (October 1991): 67–73. http://dx.doi.org/10.1677/joe.0.1310067.
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ABSTRACT The effects of thyroid state on liver mitochondrial protein mass was investigated in rats at 24 and 4 °C, as was oxidative phosphorylation using substrates which represent the final catabolic products of the metabolic fuels. In rats at 24 °C, a significant increase in mitochondrial protein mass (about +40%) was observed only in hyperthyroid animals, while a significant increase due to cold exposure was found in hypothyroid (+ 45%) and euthyroid (+ 35%) rats. In rats at 24 °C, hypothyroidism significantly decreased the oxidation of glutamate and palmitoyl carnitine but not of pyruvate, while hyperthyroidism only increased the oxidation of palmitoyl carnitine. On the other hand, exposure to cold significantly increased the oxidation of glutamate and pyruvate only in the presence of tri-iodothyronine. Our results underline not only the fact that a simple and single hypothesis for thyroid effects cannot be adopted, but also that any study concerning oxidative metabolism should be carried out using different substrates and involving different pathways of oxidation. Journal of Endocrinology (1991) 131, 67–73
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Sun, Yi, Wen-Jia Zhang, Xin Zhao, Ren-Pei Yuan, Hui Jiang, and Xiao-Ping Pu. "PARK7 protein translocating into spermatozoa mitochondria in Chinese asthenozoospermia." REPRODUCTION 148, no. 3 (September 2014): 249–57. http://dx.doi.org/10.1530/rep-14-0222.
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PARK7 (DJ1) is a multifunctional oxidative stress response protein that protects cells against reactive oxygen species (ROS) and mitochondrial damage. PARK7 defects are known to cause various physiological dysfunctions, including infertility. Asthenozoospermia (AS), i.e. low-motile spermatozoa in the ejaculate, is a common cause of human male infertility. In this study, we found that downregulation of PARK7 resulted in increased levels of lipid peroxide and ROS, decreased mitochondrial membrane potential, and reduced mitochondrial complex I enzyme activity in the spermatozoa from AS patients. Furthermore, it was observed that PARK7 was translocated into the mitochondria of damaged spermatozoa in AS. Finally, we examined the oxidative state of PARK7 and the results demonstrated the enhancement of oxidation, expressed by increased sulfonic acid residues, the highest form of oxidation, as the sperm motility decreased. Taken together, these results revealed that PARK7 deficiency may increase the oxidative stress damage to spermatozoa. Our present findings open new avenues of therapeutic intervention targeting PARK7 for the treatment of AS.
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HOLNESS, Mark J., Karen BULMER, Geoffrey F. GIBBONS, and Mary C. SUGDEN. "Up-regulation of pyruvate dehydrogenase kinase isoform 4 (PDK4) protein expression in oxidative skeletal muscle does not require the obligatory participation of peroxisome-proliferator-activated receptor α (PPARα)." Biochemical Journal 366, no. 3 (September 15, 2002): 839–46. http://dx.doi.org/10.1042/bj20020754.
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In insulin deficiency, increased lipid delivery and oxidation suppress skeletal-muscle glucose oxidation by inhibiting pyruvate dehydrogenase complex (PDC) activity via enhanced protein expression of pyruvate dehydrogenase kinase (PDK) isoform 4, which phosphorylates (and inactivates) PDC. Signalling via peroxisome-proliferator-activated receptor α (PPARα) is an important component of the mechanism enhancing hepatic and renal PDK4 protein expression. Activation of PPARα in gastrocnemius, a predominantly fast glycolytic (FG) muscle, also increases PDK4 expression, an effect that, if extended to all muscles, would be predicted to drastically restrict whole-body glucose disposal. Paradoxically, chronic activation of PPARα by WY14,643 treatment improves glucose utilization by muscles of insulin-resistant high-fat-fed rats. In the resting state, oxidative skeletal muscles are quantitatively more important for glucose disposal than FG muscles. We evaluated the participation of PPARα in regulating PDK4 protein expression in slow oxidative (SO) skeletal muscle (soleus) and fast oxidative-glycolytic (FOG) skeletal muscle (anterior tibialis) containing a high proportion of oxidative fibres. In the fed state, acute (24h) activation of PPARα by WY14,643 in vivo failed to modify PDK4 protein expression in soleus, but modestly enhanced PDK4 protein expression in anterior tibialis. Starvation enhanced PDK4 protein expression in both muscles, with the greater response in anterior tibialis. WY14,643 treatment in vivo during starvation did not further enhance upregulation of PDK4 protein expression in either muscle type. Enhanced PDK4 protein expression after starvation was retained in SO and FOG skeletal muscles of PPARα-deficient mice. Our data indicate that PDK4 protein expression in oxidative skeletal muscle is regulated by a lipid-dependent mechanism that is not obligatorily dependent on signalling via PPARα.
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Weiner, Lev, and Israel Silman. "Oxidative stress transfers protein into “molten globule”-like state." Free Radical Biology and Medicine 15, no. 5 (November 1993): 524. http://dx.doi.org/10.1016/0891-5849(93)90386-9.
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Théron, Laetitia, Aline Bonifacie, Jérémy Delabre, Thierry Sayd, Laurent Aubry, Philippe Gatellier, Christine Ravel, et al. "Investigation by Synchrotron Radiation Circular Dichroism of the Secondary Structure Evolution of Pepsin under Oxidative Environment." Foods 10, no. 5 (May 2, 2021): 998. http://dx.doi.org/10.3390/foods10050998.
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Food processing affects the structure and chemical state of proteins. In particular, protein oxidation occurs and may impair protein properties. These chemical reactions initiated during processing can develop during digestion. Indeed, the physicochemical conditions of the stomach (oxygen pressure, low pH) favor oxidation. In that respect, digestive proteases may be affected as well. Yet, very little is known about the link between endogenous oxidation of digestive enzymes, their potential denaturation, and, therefore, food protein digestibility. Thus, the objective of this study is to understand how oxidative chemical processes will impact the pepsin secondary structure and its hydrolytic activity. The folding and unfolding kinetics of pepsin under oxidative conditions was determined using Synchrotron Radiation Circular Dichroism. SRCD gave us the possibility to monitor the rapid kinetics of protein folding and unfolding in real-time, giving highly resolved spectral data. The proteolytic activity of control and oxidized pepsin was investigated by MALDI-TOF mass spectrometry on a meat protein model, the creatine kinase. MALDI-TOF MS allowed a rapid evaluation of the proteolytic activity through peptide fingerprint. This study opens up new perspectives by shifting the digestion paradigm taking into account the gastric digestive enzyme and its substrate.
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Prasad, Ankush, Hana Duchová, Renuka Ramalingam Manoharan, Deepak Rathi, and Pavel Pospíšil. "Imaging and Characterization of Oxidative Protein Modifications in Skin." International Journal of Molecular Sciences 24, no. 4 (February 16, 2023): 3981. http://dx.doi.org/10.3390/ijms24043981.
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Skin plays an important role in protection, metabolism, thermoregulation, sensation, and excretion whilst being consistently exposed to environmental aggression, including biotic and abiotic stresses. During the generation of oxidative stress in the skin, the epidermal and dermal cells are generally regarded as the most affected regions. The participation of reactive oxygen species (ROS) as a result of environmental fluctuations has been experimentally proven by several researchers and is well known to contribute to ultra-weak photon emission via the oxidation of biomolecules (lipids, proteins, and nucleic acids). More recently, ultra-weak photon emission detection techniques have been introduced to investigate the conditions of oxidative stress in various living systems in in vivo, ex vivo and in vitro studies. Research into two-dimensional photon imaging is drawing growing attention because of its application as a non-invasive tool. We monitored spontaneous and stress-induced ultra-weak photon emission under the exogenous application of a Fenton reagent. The results showed a marked difference in the ultra-weak photon emission. Overall, these results suggest that triplet carbonyl (3C=O∗) and singlet oxygen (1O2) are the final emitters. Furthermore, the formation of oxidatively modified protein adducts and protein carbonyl formation upon treatment with hydrogen peroxide (H2O2) were observed using an immunoblotting assay. The results from this study broaden our understanding of the mechanism of the generation of ROS in skin layers and the formation/contribution of various excited species can be used as tools to determine the physiological state of the organism.
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Keller, Jeffrey N. "Interplay Between Oxidative Damage, Protein Synthesis, and Protein Degradation in Alzheimer's Disease." Journal of Biomedicine and Biotechnology 2006 (2006): 1–3. http://dx.doi.org/10.1155/jbb/2006/12129.
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Protein synthesis and protein degradation are highly regulated cellular processes that are essential to maintaining cell viability. Numerous studies now indicate that protein synthesis and protein degradation are significantly altered in Alzheimer's disease (AD), with impairments in these two processes potentially contributing to AD pathogenesis. Alterations in steady state protein regulation may be a particularly important factor in regulating whether cells maintain homeostasis in response to oxidative damage, or conversely whether oxidative stress is induced by oxidative damage. The focus of this review is to discuss recent findings on each of these topics, and to discuss their importance to the onset and progression of AD.
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Suzuki, Yuichiro J., Lucia Marcocci, Takashi Shimomura, Yuki Tatenaka, Yuya Ohuchi, and Tinatin I. Brelidze. "Protein Redox State Monitoring Studies of Thiol Reactivity." Antioxidants 8, no. 5 (May 22, 2019): 143. http://dx.doi.org/10.3390/antiox8050143.
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Protein cysteine thiol status is a major determinant of oxidative stress and oxidant signaling. The -SulfoBiotics- Protein Redox State Monitoring Kit provides a unique opportunity to investigate protein thiol states. This system adds a 15-kDa Protein-SHifter to reduced cysteine residues, and this molecular mass shift can be detected by gel electrophoresis. Even in biological samples, Protein-SHifter Plus allows the thiol states of specific proteins to be studied using Western blotting. Peroxiredoxin 6 (Prx6) is a unique one-cysteine peroxiredoxin that scavenges peroxides by utilizing conserved Cysteine-47. Human Prx6 also contains an additional non-conserved cysteine residue, while rat Prx6 only has the catalytic cysteine. In cultured cells, cysteine residues of Prx6 were found to be predominantly fully reduced. The treatment of human cells with hydrogen peroxide (H2O2) formed Prx6 with one cysteine reduced. Since catalytic cysteine becomes oxidized in rat cells by the same H2O2 treatment and treating denatured human Prx6 with H2O2 results in the oxidation of both cysteines, non-conserved cysteine may not be accessible to H2O2 in human cells. We also found that untreated cells contained Prx6 multimers bound through disulfide bonds. Surprisingly, treating cells with H2O2 eliminated these Prx6 multimers. In contrast, treating cell lysates with H2O2 promoted the formation of Prx6 multimers. Similarly, treating purified preparations of the recombinant cyclic nucleotide-binding domain of the human hyperpolarization-activated cyclic nucleotide-modulated channels with H2O2 promoted the formation of multimers. These studies revealed that the cellular environment defines the susceptibility of protein cysteines to H2O2 and determines whether H2O2 acts as a facilitator or a disrupter of disulfide bonds.
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Agarwal, Rajiv. "Proinflammatory effects of oxidative stress in chronic kidney disease: role of additional angiotensin II blockade." American Journal of Physiology-Renal Physiology 284, no. 4 (April 1, 2003): F863—F869. http://dx.doi.org/10.1152/ajprenal.00385.2002.
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Oxidative stress plays an important role in causing progressive chronic kidney disease (CKD). We examined the influence of add-on ANG II receptor blockade administered as losartan (50 mg/day for 1 mo) on oxidative stress and proinflammatory state of the kidney in patients with CKD. All subjects were taking an angiotensin-converting enzyme inhibitor plus other antihypertensive agents. Oxidative stress to lipids and proteins was measured by an HPLC assay for malondialdehyde (MDA) and carbonyl concentration, respectively. Urinary inflammation was measured by monocyte chemotactic protein-1 (MCP-1) excretion rate. The etiology of CKD was type 2 diabetes mellitus in 12 and glomerulonephritis in 4 patients. There was no change in proteinuria or 24-h ambulatory blood pressure (BP) with add-on ANG II receptor blockade with losartan therapy. Before losartan therapy, urinary protein and albumin oxidation were 99 and 71% higher, respectively, compared with in plasma ( P < 0.05). There was a 35% reduction in urinary oxidized albumin with add-on losartan therapy ( P = 0.036). Urinary and plasma MDA were elevated compared with age-matched controls. Urinary MDA was significantly reduced from 4.75 ± 3.23 to 3.39 ± 2.17 μmol/g creatinine with add-on losartan therapy. However, plasma MDA or oxidized proteins did not change in response to additional ANG II blockade. A good correlation was seen between the change in urinary oxidized albumin and MCP-1 levels ( r= 0.61, P = 0.012). These data demonstrate that oxidative damage to urinary protein and lipids can be reduced with additional ANG II receptor blockade, independently of reductions in proteinuria or BP. Urinary measurements of markers of oxidative damage to lipids and proteins appear to be more sensitive than plasma measurements in patients with CKD. The significant association of the change in urinary MCP-1 with a reduction in oxidative stress supports the role of the redox state in the kidney with renal fibrosis and progressive kidney damage.
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Rocca, Bianca, Roberto Marchioli, Raffaele Landolfi, and Raimondo De Cristofaro. "Plasma Protein Oxidation Is Associated with an Increase of Procoagulant Markers Causing an Imbalance between Pro- and Anticoagulant Pathways in Healthy Subjects." Thrombosis and Haemostasis 87, no. 01 (2002): 58–67. http://dx.doi.org/10.1055/s-0037-1612944.
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SummaryThe aim of the present study was to investigate whether the overall oxidation state of plasma proteins is associated with changes of circulating pro- and anticoagulant markers in healthy subjects (n = 99, 49 males, 50 females, aged from 6 to 91 yrs.). The carbonyl content of plasma proteins was measured and validated as an ex vivo index of the overall protein oxidation state due to its correlation with the plasma level of o-tyrosine (r = 0.87, P <0.0001), which is a well known oxidized product of L-phenylalanine. Using a multivariate analysis the carbonyl content of plasma protein was positively associated with procoagulant markers such as prothrombin F1 + 2 (r = 0.28, P = 0.0019) and fibrinopeptide A, (FpA) (r = 0.278, P = 0.003), as well as with the soluble derivative of the endothelial protein thrombomodulin (TM) (r = 0.469, P <0.0001). The procoagulant marker of thrombin activity, FpA, was significantly and positively correlated with the anticoagulant product of thrombin, namely the Protein C activation peptide (PCP), only in the tertile with low protein carbonyl content. At higher tertiles this correlation was no longer observed, thus suggesting a detrimental effect of oxidative stress on the TM/Protein C anticoagulant pathway. In 15 subjects with high carbonyl content of plasma protein, treatment for 18 days with 600 mg/d of vitamin E did not substantially modify the protein carbonyl content, the anticoagulant markers APC/PCP, and all procoagulant markers except F1+2, whose value significantly decreased by 25%.In conclusion, the present study shows that a high plasma protein oxidation ex vivo is associated with an overall hemostatic imbalance, which favors procoagulant markers. Vitamin E treatment in vivo restores only in part the equilibrium between pro- and anticoagulant pathways. This may open the way to further studies aimed at elucidating the mechanisms by which the oxidative stress is linked to activation of the coagulation system in atherothrombotic disorders. Abbreviations: APC: activated Protein C; F1+2: prothrombin fragment 1+2; FpA: fibrinopeptide A; PCP: Protein C activation peptide; TM: thrombomodulin
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Jessop, C. E., S. Chakravarthi, R. H. Watkins, and N. J. Bulleid. "Oxidative protein folding in the mammalian endoplasmic reticulum." Biochemical Society Transactions 32, no. 5 (October 26, 2004): 655–58. http://dx.doi.org/10.1042/bst0320655.
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Native disulphide bonds are essential for the structure and function of many membrane and secretory proteins. Disulphide bonds are formed, reduced and isomerized in the endoplasmic reticulum of mammalian cells by a family of oxidoreductases, which includes protein disulphide isomerase (PDI), ERp57, ERp72, P5 and PDIR. This review will discuss how these enzymes are maintained in either an oxidized redox state that allows them to form disulphide bonds in substrate proteins or a reduced form that allows them to perform isomerization and reduction reactions, how these opposing pathways may co-exist within the same compartment and why so many oxidoreductases exist when PDI alone can perform all three of these functions.
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Budde, Heidi, Roua Hassoun, Melina Tangos, Saltanat Zhazykbayeva, Melissa Herwig, Marharyta Varatnitskaya, Marcel Sieme, et al. "The Interplay between S-Glutathionylation and Phosphorylation of Cardiac Troponin I and Myosin Binding Protein C in End-Stage Human Failing Hearts." Antioxidants 10, no. 7 (July 16, 2021): 1134. http://dx.doi.org/10.3390/antiox10071134.
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Oxidative stress is defined as an imbalance between the antioxidant defense system and the production of reactive oxygen species (ROS). At low levels, ROS are involved in the regulation of redox signaling for cell protection. However, upon chronical increase in oxidative stress, cell damage occurs, due to protein, DNA and lipid oxidation. Here, we investigated the oxidative modifications of myofilament proteins, and their role in modulating cardiomyocyte function in end-stage human failing hearts. We found altered maximum Ca2+-activated tension and Ca2+ sensitivity of force production of skinned single cardiomyocytes in end-stage human failing hearts compared to non-failing hearts, which was corrected upon treatment with reduced glutathione enzyme. This was accompanied by the increased oxidation of troponin I and myosin binding protein C, and decreased levels of protein kinases A (PKA)- and C (PKC)-mediated phosphorylation of both proteins. The Ca2+ sensitivity and maximal tension correlated strongly with the myofilament oxidation levels, hypo-phosphorylation, and oxidative stress parameters that were measured in all the samples. Furthermore, we detected elevated titin-based myocardial stiffness in HF myocytes, which was reversed by PKA and reduced glutathione enzyme treatment. Finally, many oxidative stress and inflammation parameters were significantly elevated in failing hearts compared to non-failing hearts, and corrected upon treatment with the anti-oxidant GSH enzyme. Here, we provide evidence that the altered mechanical properties of failing human cardiomyocytes are partially due to phosphorylation, S-glutathionylation, and the interplay between the two post-translational modifications, which contribute to the development of heart failure.
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Kojer, Kerstin, Valentina Peleh, Gaetano Calabrese, Johannes M. Herrmann, and Jan Riemer. "Kinetic control by limiting glutaredoxin amounts enables thiol oxidation in the reducing mitochondrial intermembrane space." Molecular Biology of the Cell 26, no. 2 (January 15, 2015): 195–204. http://dx.doi.org/10.1091/mbc.e14-10-1422.
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The mitochondrial intermembrane space (IMS) harbors an oxidizing machinery that drives import and folding of small cysteine-containing proteins without targeting signals. The main component of this pathway is the oxidoreductase Mia40, which introduces disulfides into its substrates. We recently showed that the IMS glutathione pool is maintained as reducing as that of the cytosol. It thus remained unclear how equilibration of protein disulfides with the IMS glutathione pool is prevented in order to allow oxidation-driven protein import. Here we demonstrate the presence of glutaredoxins in the IMS and show that limiting amounts of these glutaredoxins provide a kinetic barrier to prevent the thermodynamically feasible reduction of Mia40 substrates by the IMS glutathione pool. Moreover, they allow Mia40 to exist in a predominantly oxidized state. Consequently, overexpression of glutaredoxin 2 in the IMS results in a more reduced Mia40 redox state and a delay in oxidative folding and mitochondrial import of different Mia40 substrates. Our findings thus indicate that carefully balanced glutaredoxin amounts in the IMS ensure efficient oxidative folding in the reducing environment of this compartment.
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Al-Mshhdani, Basma A., Miranda D. Grounds, Peter G. Arthur, and Jessica R. Terrill. "A Blood Biomarker for Duchenne Muscular Dystrophy Shows That Oxidation State of Albumin Correlates with Protein Oxidation and Damage in Mdx Muscle." Antioxidants 10, no. 8 (August 3, 2021): 1241. http://dx.doi.org/10.3390/antiox10081241.
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Duchenne muscular dystrophy (DMD) is a severe X-linked muscle wasting disease with no cure. While the precise mechanisms of progressive dystropathology remain unclear, oxidative stress caused by excessive generation of oxidants is strongly implicated. Blood biomarkers that could track oxidant levels in tissues would be valuable to measure the effectiveness of clinical treatments for DMD; our research has focused on developing such biomarkers. One target of oxidants that has the potential to be harnessed as a clinical biomarker is the thiol side chain of cysteine 34 (Cys34) of the blood protein albumin. This study using the mdx mouse model of DMD shows that in plasma, albumin Cys34 undergoes thiol oxidation and these changes correlate with levels of protein thiol oxidation and damage of the dystrophic muscles. A comparison with the commonly used biomarker protein carbonylation, confirmed that albumin thiol oxidation is the more sensitive plasma biomarker of oxidative stress occurring in muscle tissue. We show that plasma albumin oxidation reflects muscle dystropathology, as increased after exercise and decreased after taurine treatment of mdx mice. These data support the use of albumin thiol oxidation as a blood biomarker of dystropathology to assist with advancing clinical development of therapies for DMD.
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Johnston, Andrew D., and Paul R. Ebert. "The Redox System inC. elegans, a Phylogenetic Approach." Journal of Toxicology 2012 (2012): 1–20. http://dx.doi.org/10.1155/2012/546915.
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Oxidative stress is a toxic state caused by an imbalance between the production and elimination of reactive oxygen species (ROS). ROS cause oxidative damage to cellular components such as proteins, lipids, and nucleic acids. While the role of ROS in cellular damage is frequently all that is noted, ROS are also important in redox signalling. The “Redox Hypothesis" has been proposed to emphasize a dual role of ROS. This hypothesis suggests that the primary effect of changes to the redox state is modified cellular signalling rather than simply oxidative damage. In extreme cases, alteration of redox signalling can contribute to the toxicity of ROS, as well as to ageing and age-related diseases. The nematode speciesCaenorhabditis elegansprovides an excellent model for the study of oxidative stress and redox signalling in animals. We use protein sequences from central redox systems inHomo sapiens,Drosophila melanogaster, andSaccharomyces cerevisiaeto query Genbank for homologous proteins inC. elegans. We then use maximum likelihood phylogenetic analysis to compare protein families betweenC. elegansand the other organisms to facilitate future research into the genetics of redox biology.
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Martinelli, Ilenia, Daniele Tomassoni, Vincenzo Bellitto, Proshanta Roy, Maria Vittoria Micioni Di Bonaventura, Francesco Amenta, Consuelo Amantini, Carlo Cifani, and Seyed Khosrow Tayebati. "Anti-Inflammatory and Antioxidant Properties of Tart Cherry Consumption in the Heart of Obese Rats." Biology 11, no. 5 (April 23, 2022): 646. http://dx.doi.org/10.3390/biology11050646.
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Obesity is a risk factor for cardiovascular diseases, frequently related to oxidative stress and inflammation. Dietary antioxidant compounds improve heart health. Here, we estimate the oxidative grade and inflammation in the heart of dietary-induced obese (DIO) rats after exposure to a high-fat diet compared to a standard diet. The effects of tart cherry seed powder and seed powder plus tart cherries juice were explored. Morphological analysis and protein expressions were performed in the heart. The oxidative status was assessed by the measurement of protein oxidation and 4-hydroxynonenal in samples. Immunochemical and Western blot assays were performed to elucidate the involved inflammatory markers as proinflammatory cytokines and cellular adhesion molecules. In the obese rats, cardiomyocyte hypertrophy was accompanied by an increase in oxidative state proteins and lipid peroxidation. However, the intake of tart cherries significantly changed these parameters. An anti-inflammatory effect was raised from tart cherry consumption, as shown by the downregulation of analyzed endothelial cell adhesion molecules and cytokines compared to controls. Tart cherry intake should be recommended as a dietary supplement to prevent or counteract heart injury in obese conditions.
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Maisonneuve, Etienne, Laetitia Fraysse, Sabrina Lignon, Laure Capron, and Sam Dukan. "Carbonylated Proteins Are Detectable Only in a Degradation-Resistant Aggregate State in Escherichia coli." Journal of Bacteriology 190, no. 20 (August 8, 2008): 6609–14. http://dx.doi.org/10.1128/jb.00588-08.
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ABSTRACT Carbonylation is currently used as a marker for irreversible protein oxidative damage. Several studies indicate that carbonylated proteins are more prone to degradation than their nonoxidized counterparts. In this study, we observed that in Escherichia coli, more than 95% of the total carbonyl content consisted of insoluble protein and most were cytosolic proteins. We thereby demonstrate that, in vivo, carbonylated proteins are detectable mainly in an aggregate state. Finally, we show that detectable carbonylated proteins are not degraded in vivo. Here we propose that some carbonylated proteins escape degradation in vivo by forming carbonylated protein aggregates and thus becoming nondegradable. In light of these findings, we provide evidence that the accumulation of nondegradable carbonylated protein presented in an aggregate state contributes to the increases in carbonyl content observed during senescence.
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Bramora, Piotr, Maria Zych, Weronka Borymska, and Ilona Kaczmarczyk-Żebrowska. "Effect of silymarin on the parameters of oxidative stress in hearts in the course of diabetes mellitus in Wistar rats." Acta Poloniae Pharmaceutica - Drug Research 79, no. 6 (March 3, 2023): 901–11. http://dx.doi.org/10.32383/appdr/159412.
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Chronic hyperglycemia is one of the most important causes of the formation of oxygen free radicals in diabetes, which damage various organs. Damage to proteins and lipids in the heart can lead to the development of diabetic cardiomyopathy, which in turn may cause cardiovascular failure. In order to counteract oxidative stress, the innate antioxidant mechanisms of the system should be supported by supplementation with exogenous antioxidants, for instance of plant origin. In this experiment, the role of silymarin, a plant-derived flavonolignan on the oxidative stress parameters and oxidative damage markers in the hearts was determined in an experimental model of diabetes. Male Wistar rats were injected with streptozotocin at a dose of 60 mg/kg (ip). Then, silymarin was administered at doses of 50 and 100 mg/kg for four weeks via a gastric tube. In diabetic animals an increase in malondialdehyde, advanced oxidation protein products, as well as increased activity of antioxidant enzymes in heart tissues was noted. Administration of silymarin inhibited oxidative stress by increasing the total antioxidant response, decreasing the concentration of malondialdehyde and advanced oxidation protein products and a slight increase in the level of glutathione. It can be concluded that the redox state in the examined tissue improved. Based on the results in can be concluded that silymarin demonstrates a potential in preventing the development of oxidative damage in the heart tissue in the course of experimental diabetes.
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Qin, Meng, Wei Wang, and D. Thirumalai. "Protein folding guides disulfide bond formation." Proceedings of the National Academy of Sciences 112, no. 36 (August 21, 2015): 11241–46. http://dx.doi.org/10.1073/pnas.1503909112.
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The Anfinsen principle that the protein sequence uniquely determines its structure is based on experiments on oxidative refolding of a protein with disulfide bonds. The problem of how protein folding drives disulfide bond formation is poorly understood. Here, we have solved this long-standing problem by creating a general method for implementing the chemistry of disulfide bond formation and rupture in coarse-grained molecular simulations. As a case study, we investigate the oxidative folding of bovine pancreatic trypsin inhibitor (BPTI). After confirming the experimental findings that the multiple routes to the folded state contain a network of states dominated by native disulfides, we show that the entropically unfavorable native single disulfide [14–38] between Cys14 and Cys38 forms only after polypeptide chain collapse and complete structuring of the central core of the protein containing an antiparallel β-sheet. Subsequent assembly, resulting in native two-disulfide bonds and the folded state, involves substantial unfolding of the protein and transient population of nonnative structures. The rate of [14–38] formation increases as the β-sheet stability increases. The flux to the native state, through a network of kinetically connected native-like intermediates, changes dramatically by altering the redox conditions. Disulfide bond formation between Cys residues not present in the native state are relevant only on the time scale of collapse of BPTI. The finding that formation of specific collapsed native-like structures guides efficient folding is applicable to a broad class of single-domain proteins, including enzyme-catalyzed disulfide proteins.
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Armengol Lopez, Sandra, Kathleen M. Botham, and Charlotte Lawson. "The Oxidative State of Chylomicron Remnants Influences Their Modulation of Human Monocyte Activation." International Journal of Vascular Medicine 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/942512.
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Chylomicron remnants (CMRs) contribute directly to human monocyte activationin vitro, by increasing reactive oxygen species (ROS) production and cell migration. In this study, the effects of the oxidative state of CMR on the degree of monocyte activation was investigated. CMR-like particles (CRLPs) were prepared in three different oxidative states, normal (CRLPs), protected from oxidation by incorporation of the antioxidant, probucol (pCRLPs), or oxidised with CuSO4(oxCRLPs). Lipid accumulation and ROS production were significantly increased in primary human monocytes incubated with CRLPs, whilst secretion on monocyte chemoattractant protein-1 was reduced, but oxCRLPs had no additional effect. In contrast, pCRLPs were taken up by monocytes to a lesser extent and had no significant effect on ROS or MCP-1 secretion. These studies suggest that the oxidative state of CMRs modulates their stimulation of the activation of peripheral blood human monocytes and that dietary antioxidants may provide some protection against these atherogenic effects.
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Gu, Sean X., Jeff W. Stevens, and Steven R. Lentz. "Regulation of thrombosis and vascular function by protein methionine oxidation." Blood 125, no. 25 (June 18, 2015): 3851–59. http://dx.doi.org/10.1182/blood-2015-01-544676.
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Abstract Redox biology is fundamental to both normal cellular homeostasis and pathological states associated with excessive oxidative stress. Reactive oxygen species function not only as signaling molecules but also as redox regulators of protein function. In the vascular system, redox reactions help regulate key physiologic responses such as cell adhesion, vasoconstriction, platelet aggregation, angiogenesis, inflammatory gene expression, and apoptosis. During pathologic states, altered redox balance can cause vascular cell dysfunction and affect the equilibrium between procoagulant and anticoagulant systems, contributing to thrombotic vascular disease. This review focuses on the emerging role of a specific reversible redox reaction, protein methionine oxidation, in vascular disease and thrombosis. A growing number of cardiovascular and hemostatic proteins are recognized to undergo reversible methionine oxidation, in which methionine residues are posttranslationally oxidized to methionine sulfoxide. Protein methionine oxidation can be reversed by the action of stereospecific enzymes known as methionine sulfoxide reductases. Calcium/calmodulin-dependent protein kinase II is a prototypical methionine redox sensor that responds to changes in the intracellular redox state via reversible oxidation of tandem methionine residues in its regulatory domain. Several other proteins with oxidation-sensitive methionine residues, including apolipoprotein A-I, thrombomodulin, and von Willebrand factor, may contribute to vascular disease and thrombosis.
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Papp, Laura V., Jun Lu, Frank Striebel, Derek Kennedy, Arne Holmgren, and Kum Kum Khanna. "The Redox State of SECIS Binding Protein 2 Controls Its Localization and Selenocysteine Incorporation Function." Molecular and Cellular Biology 26, no. 13 (July 1, 2006): 4895–910. http://dx.doi.org/10.1128/mcb.02284-05.
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ABSTRACT Selenoproteins are central controllers of cellular redox homeostasis. Incorporation of selenocysteine (Sec) into selenoproteins employs a unique mechanism to decode the UGA stop codon. The process requires the Sec insertion sequence (SECIS) element, tRNASec, and protein factors including the SECIS binding protein 2 (SBP2). Here, we report the characterization of motifs within SBP2 that regulate its subcellular localization and function. We show that SBP2 shuttles between the nucleus and the cytoplasm via intrinsic, functional nuclear localization signal and nuclear export signal motifs and that its nuclear export is dependent on the CRM1 pathway. Oxidative stress induces nuclear accumulation of SBP2 via oxidation of cysteine residues within a redox-sensitive cysteine-rich domain. These modifications are efficiently reversed in vitro by human thioredoxin and glutaredoxin, suggesting that these antioxidant systems might regulate redox status of SBP2 in vivo. Depletion of SBP2 in cell lines using small interfering RNA results in a decrease in Sec incorporation, providing direct evidence for its requirement for selenoprotein synthesis. Furthermore, Sec incorporation is reduced substantially after treatment of cells with agents that cause oxidative stress, suggesting that nuclear sequestration of SBP2 under such conditions may represent a mechanism to regulate the expression of selenoproteins.
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Mussakhmetov, A., D. Utepbergenov, and B. Khassenov. "ANTIOXIDANT ROLE OF DJ-1 PROTEIN IN THE PATHOGENESIS OF PARKINSON'S DISEASE." Eurasian Journal of Applied Biotechnology, no. 4 (September 29, 2022): 3–13. http://dx.doi.org/10.11134/btp.4.2022.1.
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Parkinson's disease is a progressive age-related neurodegenerative disease, and oxidative stress is an important mediator in its pathogenesis. Loss of neurons in the midbrain region (Substantia nigra) causes dopamine deficiency and leads to the formation of intracellular inclusions containing α-synuclein aggregates. Both of these phenomena are considered neuropathological features of Parkinson's disease. Although the clinical diagnosis is based on the presence of bradykinesia and other major motor signs, Parkinson's disease is associated with many non-motor symptoms that contribute and complicate the disease. The underlying molecular pathogenesis involves several pathways and mechanisms: α-synuclein proteostasis, mitochondrial dysfunction, oxidative stress, disturbances in calcium homeostasis, and neuroinflammation.
Mutations in the PARK7 gene resulting in loss of function of the encoded DJ-1 protein have been identified as the cause of one of several forms of the inherited form of Parkinson's disease. The DJ-1 protein is attributed the role of an antioxidant based on experiments in cellular model systems. The active site of DJ-1 contains a highly reactive cysteine residue (Cys106) which is oxidized under oxidative stress. It is assumed that Cys106 plays a critical role in the biological function of DJ-1, regulating antioxidant protection depending on the oxidation state of Cys106, i.e. acts as a sensor of oxidative stress. Thus, the level of oxidized DJ-1 (oxDJ-1) may serve as a possible biomarker of oxidative stress.
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Szczepanowski, Piotr, Mateusz Noszka, Dorota Żyła-Uklejewicz, Fabian Pikuła, Malgorzata Nowaczyk-Cieszewska, Artur Krężel, Kerstin Stingl, and Anna Zawilak-Pawlik. "HP1021 is a redox switch protein identified in Helicobacter pylori." Nucleic Acids Research 49, no. 12 (June 17, 2021): 6863–79. http://dx.doi.org/10.1093/nar/gkab440.
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Abstract Helicobacter pylori is a gram-negative, microaerophilic, pathogenic bacterium and a widespread colonizer of humans. H. pylori has developed mechanisms that enable it to overcome the harsh environment of the human stomach, including reactive oxygen species (ROS). Interestingly, up to now no typical regulator dedicated to the oxidative-stress response has been discovered. In this work, we reveal that the inhibitor of replication initiation HP1021 functions as a redox switch protein in H. pylori and plays an important role in response to oxidative stress of the gastric pathogen. Each of the two predicted HP1021 domains contains three cysteine residues. We show that the cysteine residues of HP1021 are sensitive to oxidation both in vitro and in vivo, and we demonstrate that HP1021 DNA-binding activity to oriC depends on the redox state of the protein. Moreover, Zn2+ modulates HP1021 affinity towards oriC template DNA. Transcription analysis of selected H. pylori genes by RT-qPCR indicated that HP1021 is directly involved in the oxygen-dependent control of H. pylori fecA3 and gluP genes, which are implicated in response to oxidative stress. In conclusion, HP1021 is a redox switch protein and could be a target for H. pylori control strategies.
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Rothschild, Jeffrey A., Andrew E. Kilding, Sophie C. Broome, Tom Stewart, John B. Cronin, and Daniel J. Plews. "Pre-Exercise Carbohydrate or Protein Ingestion Influences Substrate Oxidation but Not Performance or Hunger Compared with Cycling in the Fasted State." Nutrients 13, no. 4 (April 14, 2021): 1291. http://dx.doi.org/10.3390/nu13041291.
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Nutritional intake can influence exercise metabolism and performance, but there is a lack of research comparing protein-rich pre-exercise meals with endurance exercise performed both in the fasted state and following a carbohydrate-rich breakfast. The purpose of this study was to determine the effects of three pre-exercise nutrition strategies on metabolism and exercise capacity during cycling. On three occasions, seventeen trained male cyclists (VO2peak 62.2 ± 5.8 mL·kg−1·min−1, 31.2 ± 12.4 years, 74.8 ± 9.6 kg) performed twenty minutes of submaximal cycling (4 × 5 min stages at 60%, 80%, and 100% of ventilatory threshold (VT), and 20% of the difference between power at the VT and peak power), followed by 3 × 3 min intervals at 80% peak aerobic power and 3 × 3 min intervals at maximal effort, 30 min after consuming a carbohydrate-rich meal (CARB; 1 g/kg CHO), a protein-rich meal (PROTEIN; 0.45 g/kg protein + 0.24 g/kg fat), or water (FASTED), in a randomized and counter-balanced order. Fat oxidation was lower for CARB compared with FASTED at and below the VT, and compared with PROTEIN at 60% VT. There were no differences between trials for average power during high-intensity intervals (367 ± 51 W, p = 0.516). Oxidative stress (F2-Isoprostanes), perceived exertion, and hunger were not different between trials. Overall, exercising in the overnight-fasted state increased fat oxidation during submaximal exercise compared with exercise following a CHO-rich breakfast, and pre-exercise protein ingestion allowed similarly high levels of fat oxidation. There were no differences in perceived exertion, hunger, or performance, and we provide novel data showing no influence of pre-exercise nutrition ingestion on exercise-induced oxidative stress.
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Murphy, M. E., and J. P. Kehrer. "Oxidation state of tissue thiol groups and content of protein carbonyl groups in chickens with inherited muscular dystrophy." Biochemical Journal 260, no. 2 (June 1, 1989): 359–64. http://dx.doi.org/10.1042/bj2600359.
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Indirect evidence suggests that oxidative stress may play a role in the pathogenesis of inherited muscular dystrophy, but the significance and precise extent of this contribution is poorly understood. Compared with normal muscle, significantly higher contents of glutathione, glutathione disulphide, protein-glutathione mixed disulphides and protein carbonyl groups, and significantly lower contents of free protein thiol groups, were found in pectoralis major muscle of genetically dystrophic chickens (the muscle affected by this disease) at 4 weeks of age. Other tissues did not show such marked disease-related differences. Interestingly, the protein pool in normal, but not dystrophic, pectoralis major muscle was relatively less oxidized in relation to the glutathione pool as compared with other tissues studied. The mechanisms by which this unique relationship between the thiol pools is maintained remain unknown. Although the physiological consequences of the increased content of protein carbonyl groups and the altered thiol pools in dystrophic muscle are not clear, the changes evident at such a young age are consistent with the occurrence of oxidative stress and may reflect significant damage to cellular proteins in this disease.
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Sánchez-Gómez, Francisco J., Cristina Espinosa-Díez, Megha Dubey, Madhu Dikshit, and Santiago Lamas. "S-glutathionylation: relevance in diabetes and potential role as a biomarker." Biological Chemistry 394, no. 10 (October 1, 2013): 1263–80. http://dx.doi.org/10.1515/hsz-2013-0150.
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Abstract Glutathione is considered the main regulator of redox balance in the cellular milieu due to its capacity for detoxifying deleterious molecules. The oxidative stress induced as a result of a variety of stimuli promotes protein oxidation, usually at cysteine residues, leading to changes in their activity. Mild oxidative stress, which may take place in physiological conditions, induces the reversible oxidation of cysteines to sulfenic acid form, while pathological conditions are associated with higher rates of reactive oxygen species production, inducing the irreversible oxidation of cysteines. Among these, neurodegenerative disorders, cardiovascular diseases and diabetes have been proposed to be pathogenetically linked to this state. In diabetes-associated vascular complications, lower levels of glutathione and increased oxidative stress have been reported. S-glutathionylation has been proposed as a posttranslational modification able to protect proteins from over-oxidizing environments. S-glutathionylation has been identified in proteins involved in diabetic models both in vitro and in vivo. In all of them, S-glutathionylation represents a mechanism that regulates the response to diabetic conditions, and has been described to occur in erythrocytes and neutrophils from diabetic patients. However, additional studies are necessary to discern whether this modification represents a biomarker for the early onset of diabetic vascular complications.
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Galiniak, Sabina, Mateusz Mołoń, Marek Biesiadecki, Agnieszka Mokrzyńska, and Krzysztof Balawender. "Oxidative Stress Markers in Urine and Serum of Patients with Bladder Cancer." Antioxidants 12, no. 2 (January 26, 2023): 277. http://dx.doi.org/10.3390/antiox12020277.
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Oxidative stress is defined as an imbalanced state of the production of reactive oxygen species and antioxidant capacity that causes oxidative damage to biomolecules, leading to cell injury and finally death. Oxidative stress mediates the development and progression of several cancer diseases, including bladder cancer. The aim of our study was to determine markers of levels of the oxidative stress in serum and urine in the same patients in parallel in serum and urine. Furthermore, we tried to estimate the associations between oxidative stress markers and the type of cancer, its clinical stage and grade, as the well as correlations between serum and urinary markers in patients with bladder cancer. Sixty-one bladder cancer and 50 healthy volunteers as a control group were included. We determined the serum and urine levels of advanced oxidation protein products (AOPP), Amadori products, total antioxidant capacity, total oxidant status (TOS), oxidative status index (OSI), and malondialdehyde. We confirm that almost all markers are elevated in serum and urine from patients with bladder cancer than from healthy subjects. Moreover, we did not find differences in the level of oxidative stress markers and the type of tumor, its clinical stage, and grade. We noted correlations between serum and urinary biomarkers, in particular TOS and OSI. Our results clearly indicate the participation of oxidative stress in the development of bladder cancer.
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Mikheytseva, I. N., and V. R. Yurevich. "BENFOTHIAMINE AS AN ANTIOXIDANT IN THE DRAINAGE ZONE OF THE EYE IN COMBINED MODELING GLACOMA AND DIABETES." Fiziolohichnyĭ zhurnal 68, no. 2 (March 11, 2022): 68–73. http://dx.doi.org/10.15407/fz68.02.068.
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During experimental glaucoma with diabetes in rabbits, in the filtering tissues of the eye, a state of oxidative stress is formed manifested by a significant decrease in the activity of antioxidant enzymes and the accumulation of products of free radical oxidation of lipids and proteins. Administration of a lipid-soluble form of vitamin B1 benfotiamine effectively reduced the manifestations of oxidative stress in the tissues of the anterior chamber of the animal eyes. This biologically active substance increased antioxidant capacity in tissues by activating antiradical protection enzymes: superoxide dismutase activity increased by 51%, catalase by 36% and glutathione peroxidase by 45% compared to the untreated animals. In addition, the processes of lipid peroxidation and oxidative destruction of protein molecules were decreased under the influence of benfotiamine. The level of malondialdehyde (MDA) was reduced by 47%, and the marker of oxidative damage to proteins of CO-groups by 35% relative to the untreated group. The results obtained may be a basis for further studies of the pharmacological substance benfotiamine in the clinic of glaucoma accompanied by diabetes, which will expand the arsenal of pathogenetically sound therapy of this serious disease.
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Arai, Kenta, and Michio Iwaoka. "Flexible Folding: Disulfide-Containing Peptides and Proteins Choose the Pathway Depending on the Environments." Molecules 26, no. 1 (January 2, 2021): 195. http://dx.doi.org/10.3390/molecules26010195.
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In the last few decades, development of novel experimental techniques, such as new types of disulfide (SS)-forming reagents and genetic and chemical technologies for synthesizing designed artificial proteins, is opening a new realm of the oxidative folding study where peptides and proteins can be folded under physiologically more relevant conditions. In this review, after a brief overview of the historical and physicochemical background of oxidative protein folding study, recently revealed folding pathways of several representative peptides and proteins are summarized, including those having two, three, or four SS bonds in the native state, as well as those with odd Cys residues or consisting of two peptide chains. Comparison of the updated pathways with those reported in the early years has revealed the flexible nature of the protein folding pathways. The significantly different pathways characterized for hen-egg white lysozyme and bovine milk α-lactalbumin, which belong to the same protein superfamily, suggest that the information of protein folding pathways, not only the native folded structure, is encoded in the amino acid sequence. The application of the flexible pathways of peptides and proteins to the engineering of folded three-dimensional structures is an interesting and important issue in the new realm of the current oxidative protein folding study.
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Morgan, Bruce, and Hui Lu. "Oxidative folding competes with mitochondrial import of the small Tim proteins." Biochemical Journal 411, no. 1 (March 13, 2008): 115–22. http://dx.doi.org/10.1042/bj20071476.
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All small Tim proteins of the mitochondrial intermembrane space contain two conserved CX3C motifs, which form two intramolecular disulfide bonds essential for function, but only the cysteine-reduced, but not oxidized, proteins can be imported into mitochondria. We have shown that Tim10 can be oxidized by glutathione under cytosolic concentrations. However, it was unknown whether oxidative folding of other small Tims can occur under similar conditions and whether oxidative folding competes kinetically with mitochondrial import. In the present study, the effect of glutathione on the cysteine-redox state of Tim9 was investigated, and the standard redox potential of Tim9 was determined to be approx. −0.31 V at pH 7.4 and 25 °C with both the wild-type and Tim9F43W mutant proteins, using reverse-phase HPLC and fluorescence approaches. The results show that reduced Tim9 can be oxidized by glutathione under cytosolic concentrations. Next, we studied the rate of mitochondrial import and oxidative folding of Tim9 under identical conditions. The rate of import was approx. 3-fold slower than that of oxidative folding of Tim9, resulting in approx. 20% of the precursor protein being imported into an excess amount of mitochondria. A similar correlation between import and oxidative folding was obtained for Tim10. Therefore we conclude that oxidative folding and mitochondrial import are kinetically competitive processes. The efficiency of mitochondrial import of the small Tim proteins is controlled, at least partially in vitro, by the rate of oxidative folding, suggesting that a cofactor is required to stabilize the cysteine residues of the precursors from oxidation in vivo.
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Koshel, Ivanna. "Level of Arachidonic Acid and State of Peroxidation Processes in Patients with Aspirin-Intolerant Polypous Rhinosinusitis." Galician Medical Journal 23, no. 4 (November 5, 2016): 2016410. http://dx.doi.org/10.21802/gmj.2016.4.10.
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The main peculiarity of aspirin-intolerant polypous rhinosinusitis pathogenesis is the presence of “genetic block” of constitutive cyclooxygenase being the key enzyme of the arachidonic acid metabolism. It justifies the necessity of studying its metabolic peculiarities.The objective of the research was to determine the level of arachidonic acid as well as the state of lipid and protein peroxidation processes in patients with aspirin-intolerant polypous rhinosinusitis.Materials and methods. The levels of arachidonic acid, malondialdehyde and oxidative modification of serum proteins were studied in 20 patients with aspirin-intolerant polypous rhinosinusitis and 7 healthy individuals.Results. Significantly elevated levels of arachidonic levels were observed. The search for alternative metabolic pathways stimulated lipid and protein peroxidation processes and led to the increase in the levels of malondialdehyde and oxidative modification of serum proteins. The peculiarities of biochemical changes indicated pro-inflammatory orientation of lipid metabolism.Conclusions. The obtained data confirmed the hypothesis of “genetic block” of the arachidonic acid metabolism as the main pathogenetic component of aspirin-intolerant polypous rhinosinusitis and allowed us to clearly interpret biochemical picture of the disease.
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Mezghrani, A. "Manipulation of oxidative protein folding and PDI redox state in mammalian cells." EMBO Journal 20, no. 22 (November 15, 2001): 6288–96. http://dx.doi.org/10.1093/emboj/20.22.6288.
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CONCONI, Mariangela, Isabelle PETROPOULOS, Istvan EMOD, Evelyne TURLIN, Francis BIVILLE, and Bertrand FRIGUET. "Protection from oxidative inactivation of the 20S proteasome byheat-shock protein 90." Biochemical Journal 333, no. 2 (July 15, 1998): 407–15. http://dx.doi.org/10.1042/bj3330407.
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Heat-shock protein 90 (Hsp 90) has been implicated in both protection against oxidative inactivation and inhibition of the multicatalytic proteinase (MCP, also known as 20 S proteasome). We report here that the protective and inhibitory effects of Hsp 90 depend on the activation state of the proteasome. Hsp 90 (and also α-crystallin) inhibits the N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activity (Cbz = benzyloxycarbonyl; MCA = 7-amido-4-methylcoumarin) when the rat liver MCP is in its latent form, but no inhibitory effects are observed when the MCP is in its active form. Metal-catalysed oxidation of the active MCP inactivates the Ala-Ala-Phe-MCA-hydrolysing (chymotrypsin-like), N-Boc-Leu-Ser-Thr-Arg-MCA-hydrolysing (trypsin-like; Boc = t-butyloxycarbonyl), N-Cbz-Leu-Leu-Glu-β-naphthylamine-hydrolysing (peptidylglutamyl-peptide hydrolase) and N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activities, whereas these activities are actually increased when the MCP is in its latent form. Hsp 90 protects against oxidative inactivation of the trypsin-like and N-Cbz-Leu-Leu-Leu-MCA-hydrolysing activities of the MCP active form, and α-crystallin protects the trypsin-like activity. The specificity of the Hsp 90-mediated protection was assessed by a quantitative analysis of the two-dimensional electrophoretic pattern of MCP subunits before and after oxidation of the MCP, in the presence or absence of Hsp 90. Treatment of the FAO hepatoma cell line with iron and ascorbate was found to inactivate the MCP. Hsp 90 overexpression obtained by challenging the cells with iron was associated with a decreased susceptibility to oxidative inactivation of the MCP trypsin-like activity. Depletion of Hsp 90 by using antisense oligonucleotides resulted in an increased susceptibility to oxidative inactivation of the MCP trypsin-like activity, providing evidence for the physiological relevance of Hsp 90-mediated protection of the MCP.
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Tabata, Fuka, Yasuaki Wada, Satomi Kawakami, and Kazuhiro Miyaji. "Serum Albumin Redox States: More Than Oxidative Stress Biomarker." Antioxidants 10, no. 4 (March 24, 2021): 503. http://dx.doi.org/10.3390/antiox10040503.
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Serum albumin is the most abundant circulating protein in mammals including humans. It has three isoforms according to the redox state of the free cysteine residue at position 34, named as mercaptalbumin (reduced albumin), non-mercaptalbumin-1 and -2 (oxidized albumin), respectively. The serum albumin redox state has long been viewed as a biomarker of systemic oxidative stress, as the redox state shifts to a more oxidized state in response to the severity of the pathological condition in various diseases such as liver diseases and renal failures. However, recent ex vivo studies revealed oxidized albumin per se could aggravate the pathological conditions. Furthermore, the possibility of the serum albumin redox state as a sensitive protein nutrition biomarker has also been demonstrated in a series of animal studies. A paradigm shift is thus ongoing in the research field of the serum albumin. This article provides an updated overview of analytical techniques for serum albumin redox state and its association with human health, focusing on recent findings.
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Tanaka, Masahiro, Teru Ishibashi, Katsuyuki Okamoto, and Masaaki Toyomizu. "Tissue- and substrate-dependent responses of oxidative phosphorylation to dietary protein level in chicks." British Journal of Nutrition 70, no. 2 (September 1993): 459–69. http://dx.doi.org/10.1079/bjn19930140.
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The ADP:O values in both cardiac and hepatic mitochondria have significantly decreased with an increase in protein level after 7, 14 and 21 d of feeding (Toyomizu et al. 1992). The present studies were undertaken to clarify tissue-specific effects of dietary protein levels on oxidative phosphorylation in the liver, kidney, skeletal muscles and small intestine and to characterize oxidative metabolism with diverse substrates in the liver. Chicks were fed on semi-purified diets of different protein levels (7, 25, 43 and 61% of metabolizable energy content) for 21 d. The responses of protein levels to oxidative phosphorylation showed tissue-dependency; although liver mitochondria of chickens fed on higher- protein diets exhibited reduced ADP:O values and state 3, neither changes in ADP:O value nor state 3 and state 4 rates were observed in the isolated mitochondria from kidney and skeletal muscles. Small intestinal mucosal mitochondria from chickens fed on a high (61%)-protein-energy diet showed significantly reduced ADP:O value and respiratory control ratio when compared with medium-protein- energy diets (25 and 43%). In liver mitochondria showing the most sensitive dependency to the levels of dietary protein, the ADP:O value decreased with increasing protein levels when pyruvate + malate- or glutamate-requiring complexes I, III and IV of the electron transport chain were used as substrates, but it did not change when succinate-requiring complexes II, III and IV or ascorbate + tetramethyl-p- phenylenediamine requiring complex IV was used. These results imply that impaired oxidative phosphorylation capacities with increasing dietary protein levels may be associated with functional damage to the respiratory chain for electron flow from NAD-linked substrates to the ubiquinone pool.
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Mailloux, Ryan J., Tyler Dumouchel, Céline Aguer, Rob deKemp, Rob Beanlands, and Mary-Ellen Harper. "Hexokinase II acts through UCP3 to suppress mitochondrial reactive oxygen species production and maintain aerobic respiration." Biochemical Journal 437, no. 2 (June 28, 2011): 301–11. http://dx.doi.org/10.1042/bj20110571.
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UCP3 (uncoupling protein-3) mitigates mitochondrial ROS (reactive oxygen species) production, but the mechanisms are poorly understood. Previous studies have also examined UCP3 effects, including decreased ROS production, during metabolic states when fatty acid oxidation is high (e.g. a fasting state). However, the role of UCP3 when carbohydrate oxidation is high (e.g. fed state) has remained largely unexplored. In the present study, we show that mitochondrial-bound HK (hexokinase) II curtails oxidative stress and enhances aerobic metabolism of glucose in the fed state in a UCP3-dependent manner. Genetic knockout or inhibition of UCP3 significantly decreased mitochondrial-bound HKII. Furthermore, UCP3 was required for the HKII-mediated decrease in mitochondrial ROS emission. Intriguingly, the UCP3-mediated modulation of mitochondria-associated HKII was only observed in cells cultured under high-glucose conditions. UCP3 was required to maintain high rates of aerobic metabolism in high-glucose-treated cells and in muscle of fed mice. Deficiency in UCP3 resulted in a metabolic shift that favoured anaerobic glycolytic metabolism, increased glucose uptake and increased sensitivity to oxidative challenge. PET (positron emission tomography) of [18F]fluoro-deoxyglucose uptake confirmed these findings in UCP3-knockout and wild-type mice. Collectively, our findings link the anti-oxidative and metabolic functions of UCP3 through a surprising molecular connection with mitochondrial-bound HKII.
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Ríos-Ocampo, W. Alfredo, María-Cristina Navas, Manon Buist-Homan, Klaas Nico Faber, Toos Daemen, and Han Moshage. "Hepatitis C Virus Proteins Core and NS5A Are Highly Sensitive to Oxidative Stress-Induced Degradation after eIF2α/ATF4 Pathway Activation." Viruses 12, no. 4 (April 9, 2020): 425. http://dx.doi.org/10.3390/v12040425.
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Hepatitis C virus (HCV) infection is accompanied by increased oxidative stress and endoplasmic reticulum stress as a consequence of viral replication, production of viral proteins, and pro-inflammatory signals. To overcome the cellular stress, hepatocytes have developed several adaptive mechanisms like anti-oxidant response, activation of Unfolded Protein Response and autophagy to achieve cell survival. These adaptive mechanisms could both improve or inhibit viral replication, however, little is known in this regard. In this study, we investigate the mechanisms by which hepatocyte-like (Huh7) cells adapt to cellular stress in the context of HCV protein overexpression and oxidative stress. Huh7 cells stably expressing individual HCV (Core, NS3/4A and NS5A) proteins were treated with the superoxide anion donor menadione to induce oxidative stress. Production of reactive oxygen species and activation of caspase 3 were quantified. The activation of the eIF2α/ATF4 pathway and changes in the steady state levels of the autophagy-related proteins LC3 and p62 were determined either by quantitative polymerase chain reaction (qPCR) or Western blotting. Huh7 cells expressing Core or NS5A demonstrated reduced oxidative stress and apoptosis. In addition, phosphorylation of eIF2α and increased ATF4 and CHOP expression was observed with subsequent HCV Core and NS5A protein degradation. In line with these results, in liver biopsies from patients with hepatitis C, the expression of ATF4 and CHOP was confirmed. HCV Core and NS5A protein degradation was reversed by antioxidant treatment or silencing of the autophagy adaptor protein p62. We demonstrated that hepatocyte-like cells expressing HCV proteins and additionally exposed to oxidative stress adapt to cellular stress through eIF2a/ATF4 activation and selective degradation of HCV pro-oxidant proteins Core and NS5A. This selective degradation is dependent on p62 and results in increased resistance to apoptotic cell death induced by oxidative stress. This mechanism may provide a new key for the study of HCV pathology and lead to novel clinically applicable therapeutic interventions.
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Shevelkova, Anna Aleksandrovna, Eduard Karpovich Aylamazyan, and Inna Ivanovna Evsyukova. "Features of oxidative modification of proteins and erythrocyte functional state in pregnancy complicated by placental insufficiency." Journal of obstetrics and women's diseases 64, no. 5 (December 15, 2015): 62–68. http://dx.doi.org/10.17816/jowd64562-68.
Full textAbstract:
Protein oxidation intensity and reduced thiols level were studied in comparison with erythrocyte functional state in pregnancy complicated by placental insufficiency. 31 women with placental insufficiency, 41 healthy pregnant and 37 healthy nonpregnant women were included. Induced protein oxidation intensity and reduced thiols level were shown to be decreased in pregnancy complicated by placental insufficiency. Erythrocyte functional state was also worsened. It correlated with protein oxidation intensity and reduced thiols level. So protein oxidation intensity, reduced thiols level and erythrocyte functional state were shown to be indicators of placental insufficiency and can be used to identify this pathology and to evaluate the effectiveness of treatment.
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Wang, Jia, Jingjing Yang, Chen Wang, Zhibai Zhao, and Yuan Fan. "Systematic Review and Meta-Analysis of Oxidative Stress and Antioxidant Markers in Oral Lichen Planus." Oxidative Medicine and Cellular Longevity 2021 (September 27, 2021): 1–16. http://dx.doi.org/10.1155/2021/9914652.
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Background. Oral lichen planus (OLP) is a relatively common chronic inflammatory disease of unknown etiology, which might be caused by oxidative stress and impaired antioxidant defense. Objective. To systematically investigate the markers of oxidative stress and antioxidant systems in the saliva and blood from OLP patients and healthy controls. Methods. The PubMed, Cochrane Library, and Embase were systematically queried to collect data from studies in which oxidative stress/antioxidant markers from OLP and healthy subjects had been evaluated until March 10, 2021. Results. A total of 28 studies fulfilled inclusion criteria, and 25 of them, having 849 OLP patients and 1,052 control subjects and analyzing 12 oxidative stress and antioxidant state marker levels, were subjected to meta-analysis. We found a significant decrease in total antioxidant capacity (TAC) and uric acid (UA) and a significant increase in malondialdehyde (MDA) and nitric oxide (NO) levels in the saliva and serum/plasma of OLP patients. Moreover, a significant elevation of 8-hydroxy-deoxyguanosine (8-OHdG) and advanced oxidation protein product (AOOP) level and a decrease in vitamin C were also observed in the saliva of the OLP group. In contrast, salivary vitamin A, zinc, glutathione peroxidase (GPx), vitamin E, and nitrite were not significantly different between the two groups. In single studies, markers of oxidative stresses such as superoxide dismutase (SOD) and 8-isoprostanelevels were elevated in OLP, and antioxidant parameters such as glutathione (GSH) and total protein (TP) levels were dysregulated. Conclusion. This meta-analysis helps to clarify the profile of oxidative stress and antioxidant state markers in OLP patients although existing evidence is rather heterogeneous and many studies are affected by several limitations. Larger and more standardized studies are warranted to ascertain whether these markers are potential causes or effects of OLP and whether antioxidant therapy improving oxidative stress will be useful.
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Lushchak, Volodymyr I. "Budding yeast Saccharomyces cerevisiae as a model to study oxidative modification of proteins in eukaryotes." Acta Biochimica Polonica 53, no. 4 (October 26, 2006): 679–84. http://dx.doi.org/10.18388/abp.2006_3295.
Full textAbstract:
The budding yeast Saccharomyces cerevisiae is a well studied unicellular eukaryotic organism the genome of which has been sequenced. The use of yeast in many commercial systems makes its investigation important not only from basic, but also from practical point of view. Yeast may be grown under both aerobic and anaerobic conditions. The investigation of the response of eukaryotes to different kinds of stresses was pioneered owing to yeast and here we focus mainly on the so-called oxidative stress. It is a result of an imbalance between the formation and decomposition of reactive oxygen species increasing their steady-state concentration. Reactive oxygen species may attack any cellular component. In the present review oxidation of proteins in S. cerevisiae is analyzed. There are two connected approaches to study oxidative protein modification - characterization of the overall process and identification of individual oxidized proteins. Because all aerobic organisms possess special systems which defend them against reactive oxygen species, the involvement of so-called antioxidant enzymes, particularly superoxide dismutase and catalase, in the protection of proteins is also analyzed.
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Stocker, Roland, and John F. Keaney. "Role of Oxidative Modifications in Atherosclerosis." Physiological Reviews 84, no. 4 (October 2004): 1381–478. http://dx.doi.org/10.1152/physrev.00047.2003.
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This review focuses on the role of oxidative processes in atherosclerosis and its resultant cardiovascular events. There is now a consensus that atherosclerosis represents a state of heightened oxidative stress characterized by lipid and protein oxidation in the vascular wall. The oxidative modification hypothesis of atherosclerosis predicts that low-density lipoprotein (LDL) oxidation is an early event in atherosclerosis and that oxidized LDL contributes to atherogenesis. In support of this hypothesis, oxidized LDL can support foam cell formation in vitro, the lipid in human lesions is substantially oxidized, there is evidence for the presence of oxidized LDL in vivo, oxidized LDL has a number of potentially proatherogenic activities, and several structurally unrelated antioxidants inhibit atherosclerosis in animals. An emerging consensus also underscores the importance in vascular disease of oxidative events in addition to LDL oxidation. These include the production of reactive oxygen and nitrogen species by vascular cells, as well as oxidative modifications contributing to important clinical manifestations of coronary artery disease such as endothelial dysfunction and plaque disruption. Despite these abundant data however, fundamental problems remain with implicating oxidative modification as a (requisite) pathophysiologically important cause for atherosclerosis. These include the poor performance of antioxidant strategies in limiting either atherosclerosis or cardiovascular events from atherosclerosis, and observations in animals that suggest dissociation between atherosclerosis and lipoprotein oxidation. Indeed, it remains to be established that oxidative events are a cause rather than an injurious response to atherogenesis. In this context, inflammation needs to be considered as a primary process of atherosclerosis, and oxidative stress as a secondary event. To address this issue, we have proposed an “oxidative response to inflammation” model as a means of reconciling the response-to-injury and oxidative modification hypotheses of atherosclerosis.
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Lachgar, Abderrahim, Neso Sojic, Stephane Arbault, Delphine Bruce, Alain Sarasin, Christian Amatore, Bernard Bizzini, Daniel Zagury, and Monique Vuillaume. "Amplification of the Inflammatory Cellular Redox State by Human Immunodeficiency Virus Type 1-Immunosuppressive Tat and gp160 Proteins." Journal of Virology 73, no. 2 (February 1, 1999): 1447–52. http://dx.doi.org/10.1128/jvi.73.2.1447-1452.1999.
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ABSTRACT In the course of our studies on oxidative stress as a component of pathological processes in humans, we showed that microintrusion into cells with microcapillary and ultramicroelectrochemical detection could mimic many types of mechanical intrusion leading to an instant (0.1 s) and high (some femtomoles) burst release of H2O2. Specific inhibitors of NADPH enzymes seem to support the assumption that this enzyme is one of the main targets of our experiments. Also, human immunodeficiency virus type 1 (HIV-1) gp160 inhibits the cooperative response of uninfected T cells as well as Tat protein release by infected cells does. In this study, we analyzed in real time, lymphocyte per lymphocyte, the T-cell response following activation in relation to the redox state. We showed that the immunosuppressive effects of HIV-1 Tat and gp160 proteins and oxidative stress are correlated, since the native but not the inactivated Tat and gp160 proteins inhibit the cellular immune response and enhance oxidative stress. These results are consistent with a role of the membrane NADPH oxidase in the cellular response to immune activation.
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Maciejczyk, Mateusz, Julita Szulimowska, Katarzyna Taranta-Janusz, Anna Wasilewska, and Anna Zalewska. "Salivary Gland Dysfunction, Protein Glycooxidation and Nitrosative Stress in Children with Chronic Kidney Disease." Journal of Clinical Medicine 9, no. 5 (April 29, 2020): 1285. http://dx.doi.org/10.3390/jcm9051285.
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This study is the first to evaluate protein glycooxidation products, lipid oxidative damage and nitrosative stress in non-stimulated (NWS) and stimulated whole saliva (SWS) of children with chronic kidney disease (CKD) divided into two subgroups: normal salivary secretion (n = 18) and hyposalivation (NWS flow < 0.2 mL min−1; n = 12). Hyposalivation was observed in all patients with severe renal failure (4–5 stage CKD), while saliva secretion > 0.2 mL/min in children with mild-moderate CKD (1–3 stage) and controls. Salivary amylase activity and total protein content were significantly lower in CKD children with hyposalivation compared to CKD patients with normal saliva secretion and control group. The fluorescence of protein glycooxidation products (kynurenine, N-formylkynurenine, advanced glycation end products), the content of oxidative damage to lipids (4-hydroxynonneal, 8-isoprostanes) and nitrosative stress (peroxynitrite, nitrotyrosine) were significantly higher in NWS, SWS, and plasma of CKD children with hyposalivation compared to patients with normal salivary secretion and healthy controls. In CKD group, salivary oxidation products correlated negatively with salivary flow rate, α-amylase activity and total protein content; however, salivary oxidation products do not reflect their plasma level. In conclusion, children with CKD suffer from salivary gland dysfunction. Oxidation of salivary proteins and lipids increases with CKD progression and deterioration of salivary gland function.