Biomarkers of reactive oxygen species serve as indicators of oxidative stress in the pathology of cardiovascular diseases. This chapter presents an overview of the various biomarkers available to quantify oxidative stress to advance the understanding of the pathophysiology of cardiovascular diseases as well as to serve as an adjunct in their diagnosis and prognosis. The plasma levels of reactive oxygen species themselves are unstable and unreliable markers of oxidative stress. The commonly used stable biomarkers are derivatives of oxygen radicals such as products of lipid peroxidation and protein oxidation, with isoprostanes and malondialdehyde (MDA) being the most widely used biomarkers due to higher specificity and ease of measurement. Recently, micro‐RNA is emerging as stable and specific biomarkers for detection of heart failure. Other biomarkers have a role in certain conditions; for example, advanced oxidation protein products indicate acute inflammation, whereas advanced glycation end products serve as indicators of chronic disease.
- reactive oxygen species
- lipid peroxidation
- cardiovascular diseases
Reactive oxygen species (ROS) are formed as by‐products of cellular activity or cellular metabolism or cellular respiration. They have useful function‐serving roles in cell signaling, cell differentiation, cell immunity, etc., when present in low concentrations, all of which are important in maintaining the body's physiological functions known as redox signaling . Their concentration is controlled by the various antioxidants produced in the body such as superoxide dismutases, catalase, and glutathione peroxidase, with the goal to keep ROS concentration low . Oxidative stress is a condition resulting from excessive reactive oxygen species due to either increased production or inadequacy of antioxidants to eliminate them. This increase in ROS results in damage to the cell which includes oxidizing lipids, nucleic acids, and proteins, thus leading to a change or loss in their function and ultimately causes cell death by apoptosis or necrosis. Due to this effect on the cells, oxidative stress has been implicated in aging  as well as many diseases including but not limited to cardiovascular disease , neurodegenerative diseases [5, 6], cancer , and diabetes .
Biomarkers are measurable characteristics of a biological condition; in this case, biomarkers of ROS serve as indicators of oxidative stress and how it influences a given disease. Hallmarks of a good biomarker are sensitivity, specificity, ease of obtaining and measuring samples, and cost‐effectiveness. The quantification of oxidative stress with biomarkers is important not only in understanding the pathophysiology of cardiovascular disease but also in the diagnosis, prognosis as well as in designing new therapeutic measures for individual intervention. Oxidative stress plays a major role in the pathology of cardiovascular disease. In the heart, oxidative stress results in the inhibition of Na+‐K- pump . The mitochondrial electron transport chain and enzymes xanthine oxidase and nicotinamide‐adenine dinucleotide phosphate (NADPH) oxidase are the main producers of ROS. Risk factors and conditions which predispose to a cardiovascular event such as smoking, hypertension, atherosclerosis, hypercholesterolemia, diabetes, and obesity increase the effect of these enzymes which results in an increased production of ROS [10, 11].
2. ROS as biomarkers
ROS themselves act as biomarkers, their plasma levels being indicators of ROS production. A method known as the reactive oxygen metabolites (ROM) kit is used to measure total oxidative stress and measures superoxides (02‐) and hydroxyl radical (HO) as well as hypochlorous acid (HOCl) and hydrogen peroxide (H2O2)  among others. This kit measures reactive oxidants in biological fluids and has been used to assess oxidative stress in animals such as in a study on ewes done by Rizzo et al. . Cytochrome C reduction has been used in many studies to measure the production of superoxide (O2-) in the atrium , mouse aorta , and vessels . Chemiluminescent probes which release photon when in contact with ROS can be detected and used for various ROS measurements with the lucigenin‐enhanced chemiluminescence being the most commonly used to understand the way superoxide and diseases related to the cardiovascular system are affected in tissues . Electron spin resonance detects free radical by the presence of its unpaired electron. Reactive radicals are detected by addition of probes . As of 2003, the spin traps were not fit to be used in humans due to the potential for toxicity, but they can be used on tissues and body fluids; for example, PBN was used to show free radicals in coronary sinus blood during bypass surgery . Aromatic traps for free radicals such as salicylate have been used in studies to detect superoxide in myocardial infarction . High levels of dityrosine, an oxidation product of ROS, have been used to demonstrate the role of oxidative damage in atherosclerotic plaques . Even though each reactive oxidant can be measured individually, they have drawbacks of being too costly and time‐consuming. Their property of being inherently unstable with short half‐lives of merely seconds, both of which combined with the antioxidants in the circulation, results in very low intracellular concentration of ROS thus making them unreliable markers of ROS.
The derivatives of oxygen radicals such as products of lipid peroxidation and protein oxidation on the other hand are stable and thus are more commonly used to measure the presence of ROS. The serum derivatives are new biomarkers of ROS which are mainly indicators of hydroperoxide levels produced by lipid peroxidation and have been shown to be high in atrial fibrillation . The diacron reactive oxygen metabolites (dROM) test is an inexpensive analysis which measures ROS in both serum and plasma.
3. Peroxidation of lipids biomarkers
Lipids, especially polyunsaturated lipids, are more susceptible to oxidative damage due to the presence of many double bonds in their molecular structure , and thus, the indicators of lipid peroxidation are important indicators of free radicals. The presence of biomarkers in cardiovascular disease confirms the hypothesis that lipid peroxidation contributes to the development of cardiovascular diseases. There are many biomarkers of lipid peroxidation—MDA and isoprostanes being the most widely used. Others are lipid hydroperoxides, oxysterols, and oxidation resistance assays.
More accurate biomarkers of lipid peroxidation are isoprostanes along with its metabolites as stated in a study done by the National Institute of Health (NIH) . In 1990, Roberts and Morrow discovered F2‐isoprostane formed by the peroxidation of arachidonic acid  which is polyunsaturated fatty acid found in the cell membrane phospholipids and is one of the many targets of ROS. They are specific indicators of lipid peroxidation both
Malondialdehyde (MDA) is a ketoaldehyde which is produced as an end product of polyunsaturated fatty acid and is found in increased concentration in tissue injury. It forms a red pigmentation when it reacts with thiobarbituric acid. This thiobarbituric acid‐reactive substance (TBARS) assay can be used to measure lipid peroxidation using spectrophotometry. In relation to cardiovascular disease, elevated levels of MDA are associated with smoking . They are seen to be elevated with the progression of atherosclerosis  and are predictors of future cardiovascular events in patients with coronary artery disease . Limitations of this method include low specificity since TBARS includes many other products of lipid peroxidation other than MDA , tendency for inaccurate results due to the varying results generated with different assay conditions used as well as the production of artifacts due to the fact that the MDA measured is mostly generated
Isolevuglandins (IsoLGs) are also produced due to oxidation of arachidonic acid, but unlike isoprostanes, they are highly reactive and react with primary amines for example phosphatidylethanolamine to form lactam and hydroxylactam. The unreacted isolevuglandins are not detected in the tissues or cells. They have been implicated in many disease processes such as atherosclerosis and neurodegenerative diseases . Though methods such as mass spectrometry and immunohistochemical studies have shown increased levels of IsoLG, there is still not enough evidence connecting them with severity of a disease or of their use in predicting the onset of disease. Further studies need to be conducted to determine the utility of IsoLG as clinical biomarkers.
7. Oxidation of proteins biomarkers
7.1. Myeloperoxidase (MPO)
MPO is an enzyme found in inflammatory cells such as macrophages and neutrophils. It generates ROS by the conversion of hydrogen peroxide to hydroxy radical (OH), nitric oxide (ONOO‐NO2), and hypochlorous acid (HOCl) and is a proinflammatory agent responsible for the oxidation of low‐density lipoprotein (LDL) . It is found in abundance in the atherosclerosis plaques  and coronary artery disease where it can serve as an inflammatory marker for both the risk of CAD and its existence . MPO concentration is measured in biological samples by ELISA which is commercially available. Its function is measured by spectrophotometry by peroxidase activity assays such as measuring the formation of guaiacol oxidation products . Its levels in the serum can predict risk for acute coronary syndromes , for risk of cardiovascular event in patients with chest pain  and increased risk of coronary artery disease in seemingly healthy population . It is prone to varying and unreliable results due to the fact that the values are altered during the process of collection and handling as seen in a study done in 2008 by Shih et al. where it was determined that the concentration of MPO varied depending on the collection tube used and the presence of heparin in the patient serum . A concern in the measurement of MPO is the artificial release of MPO from the neutrophils leading to false results showing an increase in MPO. In their study, Shih et al. used nine different types of tubes containing EDTA, citrate plasma, and heparin samples and serum samples. The level of MPO varied in all these tubes, with EDTA and citrate samples showing the lowest concentration and heparin and serum samples showing 10 and 100% higher values, respectively. This suggests that the serum levels of MPO are higher due to their release from leukocytes during coagulation. It has previously been shown by Li et al. that heparin leads to release of MPO from neutrophils during neutrophil activation .
8. Growth differentiation factor‐15
It is a cytokine expressed in many cells including cardiomyocytes . It increases in many cardiovascular diseases such as atherosclerosis  and heart failure . It has been studied with respect to the progress and outcome of disease since it has a protective role in the heart  such as against ischemia reperfusion injury  and acute myocardial infarction  making it a useful biomarker in clinical settings though more research still needs to be conducted.
9. Oxidized low‐density lipoprotein (OxLDL)
The use of OxLDL as a biomarker of oxidative stress in cardiovascular diseases has been reported due to its ability to promote lipid deposition. The oxidation of LDL is linked to the pathology of atherosclerosis by immunohistochemical staining apolipoprotein B‐100 . It is thought to be formed by activated platelets . High‐density lipoproteins (HDL) lead to decreased activation of platelets since it competes with them to bind to oxidized LDL protecting against the development of atherosclerosis . Circulating OxLDL is already proven to be able to predict the presence of atherosclerosis  and coronary artery disease . OxLDL is detected by immune assays in plasma. According to Trpkovic et al., there are currently three ELISA assays namely 4E6, E06, and DLH3 developed to detect OxLDL in the blood . Out of these, 4E6 binds to LDL but also detects native LDL and the other two, DLH3 which measures LDL and E06 are used for oxidized phosphatidylcholine . A drawback of E06 method is its non‐specificity to oxidized lipids. In 2001, Holvoet et al. measured circulating LDL levels by ELISA using monoclonal antibody 4E6 which detected higher number of circulating OxLDL in patients with coronary artery disease .
Over the years, allantoin has emerged as a reliable biomarker of oxidative damage both
11. Protein carbonyls
Oxidation of protein amino acid residues leads to the formation of protein carbonyls by different means such as deamination of glutamic acid and lysine or due to the resulting breakage of protein backbone . They are stable compounds formed early and are usually higher in concentration due to their multiple sources, making them good biomarkers due to the ease of detection as well as no need of expensive equipment. It is a commonly used protein oxidation marker, and there are various assays for its detection. They have been shown to increase with age implicating them in the process of aging . They have even been reported in the human heart following coronary surgery . Assay has been done to observe them in dilated cardiomyopathy . In 1990, Levine et al. were the first ones to determine various methods to measure carbonyls in oxidized protein .
A highly sensitive assay is protein carbonyl content (PCC) which has various modifications but in all of them 2,4‐dinitrophenylhydrazine (DNPH) reacts with the protein carbonyls and forms its 2,4‐dinitrophenyl (DNP) hydrazone which is stable and can then be optically measured by immunohistochemistry or by radioactive counting . Spectrophotometric assay can be employed due the ability of this hydrazone product to absorb ultraviolet light which when coupled with high‐performance liquid chromatography, in short HPLC, makes the measurement more specific and sensitive . One sensitive method is to detect carbonyls by first labeling them with tritiated sodium borohydride then separating with SDS‐PAGE  or by reducing with tritiated sodium borohydride in solution . An important limitation of carbonyl measurement is that there are different protocols used by researchers leading to variable levels of carbonyls in tissues.
12. Advanced oxidation protein products (AOPPS)
Advanced oxidation protein products (AOPPs) are the end products of free radical affected proteins. They have been shown to be linked to many human diseases such as diabetes mellitus , coronary artery disease , and chronic renal disease  among others, and since they have been shown to produce oxidative stress in inflammatory conditions , they serve to indicate acute inflammation.
13. Advanced glycation end products (AGES)
They are molecules which are formed as a result of the reaction between reducing sugars and amino groups. Their concentration tends to increase in conditions of oxidative stress. The two main advanced glycation end products are pentosidine and carboxymethyl valine which result from a process known as glycoxidation where the amino acids lysine and arginine react with carbohydrates as well as the oxidizing effect of ROS on polyunsaturated fatty acids. A precursor of carboxymethyl valine known as glyoxal is formed when RNase incubates with arachidonate . The presence of AGES has been shown in diseases such as diabetes mellitus and obesity among others . They also have a role in diabetic heart failure as shown by Brouwers et al., where they overexpressed glyoxalase‐I, a glycation precursor detoxifying enzyme in order to reduce AGES, and found that it leads to prevention of diabetes‐induced oxidative damage in the heart . They are detected after derivatization with 2, 4‐dinitrophenylhydrazine (DNP). The hydrazone formed is then detected using a spectrophotometer or by using anti‐DNP antibodies with along with ELISA  or by high‐performance liquid chromatography (HPLC) or by Western blot or immunohistocytochemistry . Out of these methods, HPLC is more specific and can measure carboxymethyl lysine CML  and pentosidine . They mainly serve as indicators of chronic diseases .
14. Glutathione and glutathione disulfide
Reduced glutathione (GSH) is present in large quantities in the cells and acts as an inhibitor of lipid peroxidase. Glutathione disulfide (GSSG) is the oxidized form of glutathione. Protein glutathionylation regulates cardiovascular function . Its values have been shown to increase in ischemia reperfusion injury , atherosclerosis , and cardiac hypertrophy . In patients with atherosclerosis obliterans, increased glutathionylation is shown to be related to the progression of the disease proving to be a biomarker at early stage . The ratio of GSH and GSSG is used as an indicator of ROS due to the fact that there occurs a decrease in GSH and increase in GSSG concentration in oxidative stress . There are a number of methods to detect protein s‐glutathionylation. Quantifying the total amount of s‐glutathionylated proteins is by measuring fluorescence . Labeling glutathione is a method for glutathionylation analysis such as 35s radiolabeling , though it is not very sensitive and can only be used in cell culture; furthermore, it cannot detect proteins which have already undergone glutathionylation. Biotinylated glutathione either reduced or oxidized is superior to the 35s labeling methods, it detects only glutathionylated proteins thus is specific plus it can be analyzed by multiple methods such as fluorescence microscopy  or immunoblotting using biotin antibodies . One drawback of this method is that the presence of biotin tag on glutathione may have an effect on the protein function. Antiglutathione antibodies allow the detection of glutathionylated proteins in physiological conditions. Studies done with antibodies are by using mouse monoclonal antibodies [111–113]. Drawback of antibody method is the lack of specificity, and it can only detect a few proteins in total extract  limiting its utility in detecting glutathionylated proteins on a large scale. Recently, the use of liquid chromatography‐couple mass spectrometry using whole proteins is found to be a good method to identify proteins in larger numbers .
Recently, the role of micro‐RNA (miRNA) in the generation of ROS and its consequences such as inflammation, angiogenesis, cell proliferation, and apoptosis has been a subject of research. They are found intracellularly and outside cells in body fluids . They are stable and specific such as miR‐499 miRNA for the heart. Another advantage of miRNA as a biomarker is that they are not affected by posttranslational modifications. They can also be easily assessed by methods like polymerase chain reaction (PCR) and microarrays. PCR is an expensive method which detects small quantities of miRNA, but the results are affected by the primer used. Microarray measurements require the development of probes and can thus be useful in that many RNAs can be detected at the same time . Other less used methods are direct sequencing by next‐generation sequencing , which eliminates the influence of primers as in the case of PCR but is still not used widely because of expense. Stem loop probe ligation  and Northern blotting are other methods which may be used to measure concentration of miRNA. The miRNA found most abundantly in the heart is mR‐1 which is heart specific and can be used as a sensitive and specific marker for diagnosis of acute myocardial infarction [119, 120].
Elevated miRNAs specifically miR423‐5p has also been observed in heart failure patients making them important clinical biomarkers in the diagnosis of heart failure . Although miRNA measurement has shown promise, there are still various issues that need to be addressed. The concentration of miRNA in body fluids is low making its isolation rather difficult. The values obtained also tend to be different in different body fluids which need to be normalized. Therefore, it is necessary to develop a method to obtain accurate results with miRNA measurement across the various samples . The product of DNA damage, 8 dydroxy‐2'‐deoxyguanosine urinary levels, seems to be elevated in dilated cardiomyopathy . It is also evidently a predictor of future events following myocardial infarction . Other specific biomarkers have also been studied but are not yet studied as extensively as the above biomarkers. Ascorbic acid is an endogenous antioxidant which has been linked to unstable coronary syndrome where it is thought to have an effect on the lesion . Glutathione peroxidase‐I is evidently decreased in coronary artery disease patients  which is an antioxidant enzyme. Low levels of bilirubin have been linked to cigarette smoking and increased levels of triglycerides and cholesterol making it a potential biomarker of cardiovascular disease . Oxidative bilirubin metabolites called biopyrrins are elevated in the urine in patients with heart failure  and are thought to be predictors of future cardiac events in acute myocardial infarction .
Several biomarkers of oxidative stress have been studied over the years in an effort to understand the mechanism of cardiovascular generation with the intention to use the information by targeting oxidative stress with cardio‐protective drugs. Further research into understanding the mechanism of ROS generation and their role in therapeutic intervention will be beneficial for the management of cardiovascular diseases.
Schieber, M. and N.S. Chandel, ROS function in redox signaling and oxidative stress. Curr Biol, 2014. 24(10): p. R453–62.
Miller, J.K., E. Brzezinska‐Slebodzinska, and F.C. Madsen, Oxidative stress, antioxidants, and animal function. J Dairy Sci, 1993. 76(9): p. 2812–23.
Finkel, T. and N.J. Holbrook, Oxidants, oxidative stress and the biology of ageing. Nature, 2000. 408(6809): p. 239–47.
Griendling, K.K. and G.A. FitzGerald, Oxidative stress and cardiovascular injury: Part I: basic mechanisms and in vivo monitoring of ROS. Circulation, 2003. 108(16): p. 1912–6.
Halliwell, B., Role of free radicals in the neurodegenerative diseases: therapeutic implications for antioxidant treatment. Drugs Aging, 2001. 18(9): p. 685–716.
Butterfield, D.A., Amyloid beta‐peptide (1‐42)‐induced oxidative stress and neurotoxicity: implications for neurodegeneration in Alzheimer's disease brain. A review. Free Radic Res, 2002. 36(12): p. 1307–13.
Klaunig, J.E. and L.M. Kamendulis, The role of oxidative stress in carcinogenesis. Annu Rev Pharmacol Toxicol, 2004. 44: p. 239–67.
Maritim, A.C., R.A. Sanders, and J.B. Watkins, 3rd, Diabetes, oxidative stress, and antioxidants: a review. J Biochem Mol Toxicol, 2003. 17(1): p. 24–38.
Figtree, G.A., et al., Oxidative regulation of the Na(+)–K(+) pump in the cardiovascular system. Free Radic Biol Med, 2012. 53(12): p. 2263–8.
Dikalov, S., K.K. Griendling, and D.G. Harrison, Measurement of reactive oxygen species in cardiovascular studies. Hypertension, 2007. 49(4): p. 717–27.
Touyz, R.M. and A.M. Briones, Reactive oxygen species and vascular biology: implications in human hypertension. Hypertens Res, 2011. 34(1): p. 5–14.
Reilly, P.M., H.J. Schiller, and G.B. Bulkley, Pharmacologic approach to tissue injury mediated by free radicals and other reactive oxygen metabolites. Am J Surg, 1991. 161(4): p. 488–503.
Rizzo, A., et al., First demonstration of an increased serum level of reactive oxygen species during the peripartal period in the ewes. Immunopharmacol Immunotoxicol, 2008. 30(4): p. 741–6.
Dudley, S.C., Jr., et al., Atrial fibrillation increases production of superoxide by the left atrium and left atrial appendage: role of the NADPH and xanthine oxidases. Circulation, 2005. 112(9): p. 1266–73.
Landmesser, U., et al., Oxidation of tetrahydrobiopterin leads to uncoupling of endothelial cell nitric oxide synthase in hypertension. J Clin Invest, 2003. 111(8): p. 1201–9.
Guzik, T.J., et al., Mechanisms of increased vascular superoxide production in human diabetes mellitus: role of NAD(P)H oxidase and endothelial nitric oxide synthase. Circulation, 2002. 105(14): p. 1656–62.
Clermont, G., et al., Systemic free radical activation is a major event involved in myocardial oxidative stress related to cardiopulmonary bypass. Anesthesiology, 2002. 96(1): p. 80–7.
Tubaro, M., et al., Demonstration of the formation of hydroxyl radicals in acute myocardial infarction in man using salicylate as probe. Cardiology, 1992. 80(3–4): p. 246–51.
Fu, S., et al., Evidence for roles of radicals in protein oxidation in advanced human atherosclerotic plaque. Biochem J, 1998. 333(Pt 3): p. 519–25.
Shimano, M., et al., Reactive oxidative metabolites are associated with atrial conduction disturbance in patients with atrial fibrillation. Heart Rhythm, 2009. 6(7): p. 935–40.
Porter, N.A., S.E. Caldwell, and K.A. Mills, Mechanisms of free radical oxidation of unsaturated lipids. Lipids, 1995. 30(4): p. 277–90.
Milne, G.L., et al., Quantification of F2‐isoprostanes as a biomarker of oxidative stress. Nat Protoc, 2007. 2(1): p. 221–6.
Morrow, J.D., et al., A series of prostaglandin F2‐like compounds are produced in vivo in humans by a non‐cyclooxygenase, free radical‐catalyzed mechanism. Proc Natl Acad Sci USA, 1990. 87(23): p. 9383–7.
Fam, S.S. and J.D. Morrow, The isoprostanes: unique products of arachidonic acid oxidation—a review. Curr Med Chem, 2003. 10(17): p. 1723–40.
Morrow, J.D., et al., Formation of novel non‐cyclooxygenase‐derived prostanoids (F2‐isoprostanes) in carbon tetrachloride hepatotoxicity. An animal model of lipid peroxidation. J Clin Invest, 1992. 90(6): p. 2502–7.
Iuliano, L., et al., Angioplasty increases coronary sinus F2‐isoprostane formation: evidence for in vivo oxidative stress during PTCA. J Am Coll Cardiol, 2001. 37(1): p. 76–80.
Roberts, L.J. and J.D. Morrow, Measurement of F(2)‐isoprostanes as an index of oxidative stress in vivo. Free Radic Biol Med, 2000. 28(4): p. 505–13.
Cracowski, J.L., T. Durand, and G. Bessard, Isoprostanes as a biomarker of lipid peroxidation in humans: physiology, pharmacology and clinical implications. Trends Pharmacol Sci, 2002. 23(8): p. 360–6.
Davies, S.S. and L.J. Roberts, 2nd, F2‐isoprostanes as an indicator and risk factor for coronary heart disease. Free Radic Biol Med, 2011. 50(5): p. 559–66.
Milne, G.L., Q. Dai, and L.J. Roberts, 2nd, The isoprostanes—25 years later. Biochim Biophys Acta, 2015. 1851(4): p. 433–45.
Delanty, N., et al., 8‐epi PGF2 alpha generation during coronary reperfusion. A potential quantitative marker of oxidant stress in vivo. Circulation, 1997. 95(11): p. 2492–9.
Keaney, J.F., Jr., et al., Obesity and systemic oxidative stress: clinical correlates of oxidative stress in the Framingham Study. Arterioscler Thromb Vasc Biol, 2003. 23(3): p. 434–9.
De Caterina, R., et al., Low‐density lipoprotein level reduction by the 3‐hydroxy‐3‐methylglutaryl coenzyme‐A inhibitor simvastatin is accompanied by a related reduction of F2‐isoprostane formation in hypercholesterolemic subjects: no further effect of vitamin E. Circulation, 2002. 106(20): p. 2543–9.
Gniwotta, C., et al., Prostaglandin F2‐like compounds, F2‐isoprostanes, are present in increased amounts in human atherosclerotic lesions. Arterioscler Thromb Vasc Biol, 1997. 17(11): p. 3236–41.
Ulus, A.T., et al., Cardiopulmonary bypass as a cause of free radical‐induced oxidative stress and enhanced blood‐borne isoprostanes in humans. Free Radic Biol Med, 2003. 34(7): p. 911–7.
Roberts, L.J., 2nd, et al., Identification of the major urinary metabolite of the F2‐isoprostane 8‐iso‐prostaglandin F2alpha in humans. J Biol Chem, 1996. 271(34): p. 20617–20.
Aviram, M., Review of human studies on oxidative damage and antioxidant protection related to cardiovascular diseases. Free Radic Res, 2000. 33(Suppl): p. S85–97.
Chiabrando, C., et al., Identification of metabolites from type III F2‐isoprostane diastereoisomers by mass spectrometry. J Lipid Res, 2002. 43(3): p. 495–509.
Milne, G.L., E.S. Musiek, and J.D. Morrow, F2‐isoprostanes as markers of oxidative stress in vivo: an overview. Biomarkers, 2005. 10(Suppl 1): p. S10–23.
Smith, K.A., et al., A comparison of methods for the measurement of 8‐isoPGF(2alpha): a marker of oxidative stress. Ann Clin Biochem, 2011. 48(Pt 2): p. 147–54.
Kanabrocki, E.L., et al., Circadian variation in oxidative stress markers in healthy and type II diabetic men. Chronobiol Int, 2002. 19(2): p. 423–39.
Helmersson, J. and S. Basu, F(2)‐isoprostane and prostaglandin F(2 alpha)metabolite excretion rate and day to day variation in healthy humans. Prostaglandins Leukot Essent Fatty Acids, 2001. 65(2): p. 99–102.
Miller, E.R., 3rd, et al., Association between cigarette smoking and lipid peroxidation in a controlled feeding study. Circulation, 1997. 96(4): p. 1097–101.
Salonen, J.T., et al., Lipoprotein oxidation and progression of carotid atherosclerosis. Circulation, 1997. 95(4): p. 840–5.
Walter, M.F., et al., Serum levels of thiobarbituric acid reactive substances predict cardiovascular events in patients with stable coronary artery disease: a longitudinal analysis of the PREVENT study. J Am Coll Cardiol, 2004. 44(10): p. 1996–2002.
Meagher, E.A. and G.A. FitzGerald, Indices of lipid peroxidation in vivo: strengths and limitations. Free Radic Biol Med, 2000. 28(12): p. 1745–50.
Halliwell, B. and S. Chirico, Lipid peroxidation: its mechanism, measurement, and significance. Am J Clin Nutr, 1993. 57(5 Suppl): p. 715S–724S; discussion 724S–725S.
Moore, K. and L.J. Roberts, 2nd, Measurement of lipid peroxidation. Free Radic Res, 1998. 28(6): p. 659–71.
Lykkesfeldt, J., Determination of malondialdehyde as dithiobarbituric acid adduct in biological samples by HPLC with fluorescence detection: comparison with ultraviolet‐visible spectrophotometry. Clin Chem, 2001. 47(9): p. 1725–7.
Bevan, R.J., et al., Validation of a novel ELISA for measurement of MDA‐LDL in human plasma. Free Radic Biol Med, 2003. 35(5): p. 517–27.
Salomon, R.G. and W. Bi, Isolevuglandin adducts in disease. Antioxid Redox Signal, 2015. 22(18): p. 1703–18.
Hazen, S.L. and J.W. Heinecke, 3‐Chlorotyrosine, a specific marker of myeloperoxidase‐catalyzed oxidation, is markedly elevated in low density lipoprotein isolated from human atherosclerotic intima. J Clin Invest, 1997. 99(9): p. 2075–81.
Daugherty, A., et al., Myeloperoxidase, a catalyst for lipoprotein oxidation, is expressed in human atherosclerotic lesions. J Clin Invest, 1994. 94(1): p. 437–44.
Zhang, R., et al., Association between myeloperoxidase levels and risk of coronary artery disease. JAMA, 2001. 286(17): p. 2136–42.
Capeillere‐Blandin, C., Oxidation of guaiacol by myeloperoxidase: a two‐electron‐oxidized guaiacol transient species as a mediator of NADPH oxidation. Biochem J, 1998. 336(Pt 2): p. 395–404.
Baldus, S., et al., Myeloperoxidase serum levels predict risk in patients with acute coronary syndromes. Circulation, 2003. 108(12): p. 1440–5.
Brennan, M.L., et al., Prognostic value of myeloperoxidase in patients with chest pain. N Engl J Med, 2003. 349(17): p. 1595–604.
Meuwese, M.C., et al., Serum myeloperoxidase levels are associated with the future risk of coronary artery disease in apparently healthy individuals: the EPIC‐Norfolk Prospective Population Study. J Am Coll Cardiol, 2007. 50(2): p. 159–65.
Shih, J., et al., Effect of collection tube type and preanalytical handling on myeloperoxidase concentrations. Clin Chem, 2008. 54(6): p. 1076–9.
Li, G., et al., Effects of unfractionated heparin and glycoprotein IIb/IIIa antagonists versus bivalirdin on myeloperoxidase release from neutrophils. Arterioscler Thromb Vasc Biol, 2007. 27(8): p. 1850–6.
Kempf, T., et al., The transforming growth factor‐beta superfamily member growth‐differentiation factor‐15 protects the heart from ischemia/reperfusion injury. Circ Res, 2006. 98(3): p. 351–60.
Schlittenhardt, D., et al., Involvement of growth differentiation factor‐15/macrophage inhibitory cytokine‐1 (GDF‐15/MIC‐1) in oxLDL‐induced apoptosis of human macrophages in vitro and in arteriosclerotic lesions. Cell Tissue Res, 2004. 318(2): p. 325–33.
Lindahl, B., The story of growth differentiation factor 15: another piece of the puzzle. Clin Chem, 2013. 59(11): p. 1550–2.
Ago, T. and J. Sadoshima, GDF15, a cardioprotective TGF‐beta superfamily protein. Circ Res, 2006. 98(3): p. 294–7.
Khan, S.Q., et al., Growth differentiation factor‐15 as a prognostic marker in patients with acute myocardial infarction. Eur Heart J, 2009. 30(9): p. 1057–65.
Yla‐Herttuala, S., et al., Evidence for the presence of oxidatively modified low density lipoprotein in atherosclerotic lesions of rabbit and man. J Clin Invest, 1989. 84(4): p. 1086–95.
Massberg, S., et al., Platelet adhesion via glycoprotein IIb integrin is critical for atheroprogression and focal cerebral ischemia: an in vivo study in mice lacking glycoprotein IIb. Circulation, 2005. 112(8): p. 1180–8.
Badrnya, S., A. Assinger, and I. Volf, Native high density lipoproteins (HDL) interfere with platelet activation induced by oxidized low density lipoproteins (OxLDL). Int J Mol Sci, 2013. 14(5): p. 10107–21.
Hulthe, J. and B. Fagerberg, Circulating oxidized LDL is associated with subclinical atherosclerosis development and inflammatory cytokines (AIR Study). Arterioscler Thromb Vasc Biol, 2002. 22(7): p. 1162–7.
Meisinger, C., et al., Plasma oxidized low‐density lipoprotein, a strong predictor for acute coronary heart disease events in apparently healthy, middle‐aged men from the general population. Circulation, 2005. 112(5): p. 651–7.
Trpkovic, A., et al., Oxidized low‐density lipoprotein as a biomarker of cardiovascular diseases. Crit Rev Clin Lab Sci, 2015. 52(2): p. 70–85.
Itabe, H., et al., Oxidized phosphatidylcholines that modify proteins. Analysis by monoclonal antibody against oxidized low density lipoprotein. J Biol Chem, 1996. 271(52): p. 33208–17.
Holvoet, P., et al., Circulating oxidized LDL is a useful marker for identifying patients with coronary artery disease. Arterioscler Thromb Vasc Biol, 2001. 21(5): p. 844–8.
Grootveld, M. and B. Halliwell, Measurement of allantoin and uric acid in human body fluids. A potential index of free‐radical reactions in vivo? Biochem J, 1987. 243(3): p. 803–8.
Kand'ar, R., P. Zakova, and V. Muzakova, Monitoring of antioxidant properties of uric acid in humans for a consideration measuring of levels of allantoin in plasma by liquid chromatography. Clin Chim Acta, 2006. 365(1–2): p. 249–56.
Seet, R.C., et al., Biomarkers of oxidative damage in cigarette smokers: which biomarkers might reflect acute versus chronic oxidative stress? Free Radic Biol Med, 2011. 50(12): p. 1787–93.
Doehner, W., et al., Effects of xanthine oxidase inhibition with allopurinol on endothelial function and peripheral blood flow in hyperuricemic patients with chronic heart failure: results from 2 placebo‐controlled studies. Circulation, 2002. 105(22): p. 2619–24.
Berthemy, A., et al., Quantitative determination of an extremely polar compound allantoin in human urine by LC‐MS/MS based on the separation on a polymeric amino column. J Pharm Biomed Anal, 1999. 19(3–4): p. 429–34.
Turner, R., L.K. Stamp, and A.J. Kettle, Detection of allantoin in clinical samples using hydrophilic liquid chromatography with stable isotope dilution negative ion tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci, 2012. 891–892: p. 85–9.
Dalle‐Donne, I., et al., Protein carbonyl groups as biomarkers of oxidative stress. Clin Chim Acta, 2003. 329(1–2): p. 23–38.
Mutlu‐Turkoglu, U., et al., Age‐related increases in plasma malondialdehyde and protein carbonyl levels and lymphocyte DNA damage in elderly subjects. Clin Biochem, 2003. 36(5): p. 397–400.
Pantke, U., et al., Oxidized proteins as a marker of oxidative stress during coronary heart surgery. Free Radic Biol Med, 1999. 27(9–10): p. 1080–6.
Lynch, T.L.t., et al., Oxidative stress in dilated cardiomyopathy caused by MYBPC3 mutation. Oxid Med Cell Longev, 2015. 2015: p. 424751.
Levine, R.L., et al., Determination of carbonyl content in oxidatively modified proteins. Methods Enzymol, 1990. 186: p. 464–78.
Chevion, M., E. Berenshtein, and E.R. Stadtman, Human studies related to protein oxidation: protein carbonyl content as a marker of damage. Free Radic Res, 2000. 33(Suppl): p. S99–108.
Levine, R.L., et al., Carbonyl assays for determination of oxidatively modified proteins. Methods Enzymol, 1994. 233: p. 346–57.
Yan, L.J. and R.S. Sohal, Gel electrophoretic quantitation of protein carbonyls derivatized with tritiated sodium borohydride. Anal Biochem, 1998. 265(1): p. 176–82.
Lenz, A.G., et al., Determination of carbonyl groups in oxidatively modified proteins by reduction with tritiated sodium borohydride. Anal Biochem, 1989. 177(2): p. 419–25.
Kalousova, M., J. Skrha, and T. Zima, Advanced glycation end‐products and advanced oxidation protein products in patients with diabetes mellitus. Physiol Res, 2002. 51(6): p. 597–604.
Kaneda, H., et al., Increased level of advanced oxidation protein products in patients with coronary artery disease. Atherosclerosis, 2002. 162(1): p. 221–5.
Witko‐Sarsat, V., et al., Advanced oxidation protein products as novel mediators of inflammation and monocyte activation in chronic renal failure. J Immunol, 1998. 161(5): p. 2524–32.
Witko‐Sarsat, V., et al., Advanced oxidation protein products as a novel molecular basis of oxidative stress in uraemia. Nephrol Dial Transplant, 1999. 14(Suppl 1): p. 76–8.
Fu, M.X., et al., The advanced glycation end product, Nepsilon‐(carboxymethyl)lysine, is a product of both lipid peroxidation and glycoxidation reactions. J Biol Chem, 1996. 271(17): p. 9982–6.
Brix, J.M., et al., The soluble form of the receptor of advanced glycation endproducts increases after bariatric surgery in morbid obesity. Int J Obes (Lond), 2012. 36(11): p. 1412–7.
Brouwers, O., et al., Mild oxidative damage in the diabetic rat heart is attenuated by glyoxalase‐1 overexpression. Int J Mol Sci, 2013. 14(8): p. 15724–39.
Buss, H., et al., Protein carbonyl measurement by a sensitive ELISA method. Free Radic Biol Med, 1997. 23(3): p. 361–6.
Keller, R.J., et al., Immunochemical detection of oxidized proteins. Chem Res Toxicol, 1993. 6(4): p. 430–3.
Friess, U., et al., Liquid chromatography‐based determination of urinary free and total N(epsilon)‐(carboxymethyl)lysine excretion in normal and diabetic subjects. J Chromatogr B Analyt Technol Biomed Life Sci, 2003. 794(2): p. 273–80.
Takahashi, M., et al., Direct quantification of pentosidine in urine and serum by HPLC with column switching. Clin Chem, 1996. 42(9): p. 1439–44.
Kalousova, M., et al., Advanced glycoxidation end products in chronic diseases‐clinical chemistry and genetic background. Mutat Res, 2005. 579(1–2): p. 37–46.
Mieyal, J.J., et al., Molecular mechanisms and clinical implications of reversible protein S‐glutathionylation. Antioxid Redox Signal, 2008. 10(11): p. 1941–88.
Eaton, P., et al., Glyceraldehyde phosphate dehydrogenase oxidation during cardiac ischemia and reperfusion. J Mol Cell Cardiol, 2002. 34(11): p. 1549–60.
Okuda, M., et al., Expression of glutaredoxin in human coronary arteries: its potential role in antioxidant protection against atherosclerosis. Arterioscler Thromb Vasc Biol, 2001. 21(9): p. 1483–7.
Pimentel, D.R., et al., Strain‐stimulated hypertrophy in cardiac myocytes is mediated by reactive oxygen species‐dependent Ras S‐glutathiolation. J Mol Cell Cardiol, 2006. 41(4): p. 613–22.
Nonaka, K., et al., Serum levels of S‐glutathionylated proteins as a risk‐marker for arteriosclerosis obliterans. Circ J, 2007. 71(1): p. 100–5.
Jones, D.P., Redox potential of GSH/GSSG couple: assay and biological significance. Methods Enzymol, 2002. 348: p. 93–112.
Townsend, D.M., et al., Novel role for glutathione S‐transferase pi. Regulator of protein S‐Glutathionylation following oxidative and nitrosative stress. J Biol Chem, 2009. 284(1): p. 436–45.
Lind, C., et al., Studies on the mechanism of oxidative modification of human glyceraldehyde‐3‐phosphate dehydrogenase by glutathione: catalysis by glutaredoxin. Biochem Biophys Res Commun, 1998. 247(2): p. 481–6.
Brennan, J.P., et al., The utility of N,N‐biotinyl glutathione disulfide in the study of protein S‐glutathiolation. Mol Cell Proteomics, 2006. 5(2): p. 215–25.
Reynaert, N.L., et al., Dynamic redox control of NF‐kappaB through glutaredoxin‐regulated S‐glutathionylation of inhibitory kappaB kinase beta. Proc Natl Acad Sci USA, 2006. 103(35): p. 13086–91.
Passarelli, C., et al., Susceptibility of isolated myofibrils to in vitro glutathionylation: potential relevance to muscle functions. Cytoskeleton (Hoboken), 2010. 67(2): p. 81–9.
Passarelli, C., et al., Myosin as a potential redox‐sensor: an in vitro study. J Muscle Res Cell Motil, 2008. 29(2–5): p. 119–26.
West, M.B., et al., Protein glutathiolation by nitric oxide: an intracellular mechanism regulating redox protein modification. FASEB J, 2006. 20(10): p. 1715–7.
Pastore, A. and F. Piemonte, Protein glutathionylation in cardiovascular diseases. Int J Mol Sci, 2013. 14(10): p. 20845–76.
Hanson, E.K., H. Lubenow, and J. Ballantyne, Identification of forensically relevant body fluids using a panel of differentially expressed microRNAs. Anal Biochem, 2009. 387(2): p. 303–14.
Etheridge, A., et al., Extracellular microRNA: a new source of biomarkers. Mutat Res, 2011. 717(1–2): p. 85–90.
Thomas, M.F. and K.M. Ansel, Construction of small RNA cDNA libraries for deep sequencing. Methods Mol Biol, 2010. 667: p. 93–111.
Li, J., et al., Real‐time polymerase chain reaction microRNA detection based on enzymatic stem‐loop probes ligation. Anal Chem, 2009. 81(13): p. 5446–51.
Cheng, Y., et al., A translational study of circulating cell‐free microRNA‐1 in acute myocardial infarction. Clin Sci (Lond), 2010. 119(2): p. 87–95.
Ai, J., et al., Circulating microRNA‐1 as a potential novel biomarker for acute myocardial infarction. Biochem Biophys Res Commun, 2010. 391(1): p. 73–7.
Tijsen, A.J., et al., MiR423‐5p as a circulating biomarker for heart failure. Circ Res, 2010. 106(6): p. 1035–9.
Kono, Y., et al., Elevated levels of oxidative DNA damage in serum and myocardium of patients with heart failure. Circ J, 2006. 70(8): p. 1001–5.
Nagayoshi, Y., et al., Urinary 8‐hydroxy‐2'‐deoxyguanosine levels increase after reperfusion in acute myocardial infarction and may predict subsequent cardiac events. Am J Cardiol, 2005. 95(4): p. 514–7.
Vita, J.A., et al., Low plasma ascorbic acid independently predicts the presence of an unstable coronary syndrome. J Am Coll Cardiol, 1998. 31(5): p. 980–6.
Blankenberg, S., et al., Glutathione peroxidase 1 activity and cardiovascular events in patients with coronary artery disease. N Engl J Med, 2003. 349(17): p. 1605–13.
Madhavan, M., et al., Serum bilirubin distribution and its relation to cardiovascular risk in children and young adults. Atherosclerosis, 1997. 131(1): p. 107–13.
Hokamaki, J., et al., Urinary biopyrrins levels are elevated in relation to severity of heart failure. J Am Coll Cardiol, 2004. 43(10): p. 1880–5.
Shimomura, H., et al., Comparison of urinary biopyrrin levels in acute myocardial infarction (after reperfusion therapy) versus stable angina pectoris and their usefulness in predicting subsequent cardiac events. Am J Cardiol, 2002. 90(2): p. 108–11.