mocetinostat and Cardiovascular-Diseases

Kidney disease is a strong modulator of the composition and metabolism of the intestinal microbiome that produces toxins and inflammatory factors. The primary pathways for these harmful factors are blood vessels and nerves. Although lymphatic vessels are responsible for clearance of interstitial fluids, macromolecules, and cells, little is known about whether and how kidney injury impacts the intestinal lymphatic network.. Kidney injury stimulates intestinal lymphangiogenesis, activates lymphatic endothelial cells, and increases mesenteric lymph flow. The mesenteric lymph of kidney-injured animals contains increased levels of cytokines, immune cells, isolevuglandin (IsoLG), a highly reactive dicarbonyl, and of apolipoprotein AI (apoAI). IsoLG is increased in the ileum of kidney injured animals, and intestinal epithelial cells exposed to myeloperoxidase produce more IsoLG. IsoLG-modified apoAI directly increases lymphatic vessel contractions and activates lymphatic endothelial cells. Inhibition of IsoLG by carbonyl scavenger treatment reduces intestinal lymphangiogenesis in kidney-injured animals. Research from our group and others suggests a novel mediator (IsoLG-modified apoAI) and a new pathway (intestinal lymphatic network) in the cross talk between kidneys and intestines and heart. Kidney injury activates intestinal lymphangiogenesis and increases lymphatic flow via mechanisms involving intestinally generated IsoLG. The data identify a new pathway in the kidney gut-heart axis and present a new target for kidney disease-induced intestinal disruptions that may lessen the major adverse consequence of kidney impairment, namely cardiovascular disease.

Topics: Animals; Apolipoprotein A-I; Cardiovascular Diseases; Cytokines; Endothelial Cells; Humans; Hypertension; Inflammation; Lymphatic Vessels; Peroxidase; Renal Insufficiency, Chronic

Myeloperoxidase (MPO) is a prominent mammalian heme peroxidase and a fundamental component of the innate immune response against microbial pathogens. In recent times, MPO has received considerable attention as a key oxidative enzyme capable of impairing the bioactivity of nitric oxide (NO) and promoting endothelial dysfunction; a clinically relevant event that manifests throughout the development of inflammatory cardiovascular disease. Increasing evidence indicates that during cardiovascular disease, MPO is released intravascularly by activated leukocytes resulting in its transport and sequestration within the vascular endothelium. At this site, MPO catalyzes various oxidative reactions that are capable of promoting vascular inflammation and impairing NO bioactivity and endothelial function. In particular, MPO catalyzes the production of the potent oxidant hypochlorous acid (HOCl) and the catalytic consumption of NO via the enzyme's NO oxidase activity. An emerging paradigm is the ability of MPO to also influence endothelial function via non-catalytic, cytokine-like activities. In this review article we discuss the implications of our increasing knowledge of the versatility of MPO's actions as a mediator of cardiovascular disease and endothelial dysfunction for the development of new pharmacological agents capable of effectively combating MPO's pathogenic activities. More specifically, we will (i) discuss the various transport mechanisms by which MPO accumulates into the endothelium of inflamed or diseased arteries, (ii) detail the clinical and basic scientific evidence identifying MPO as a significant cause of endothelial dysfunction and cardiovascular disease, (iii) provide an up-to-date coverage on the different oxidative mechanisms by which MPO can impair endothelial function during cardiovascular disease including an evaluation of the contributions of MPO-catalyzed HOCl production and NO oxidation, and (iv) outline the novel non-enzymatic mechanisms of MPO and their potential contribution to endothelial dysfunction. Finally, we deliver a detailed appraisal of the different pharmacological strategies available for targeting the catalytic and non-catalytic modes-of-action of MPO in order to protect against endothelial dysfunction in cardiovascular disease.

Topics: Animals; Cardiovascular Diseases; Endothelium, Vascular; Humans; Hypochlorous Acid; Nitric Oxide; Oxidation-Reduction; Peroxidase; Vascular Diseases

While the received traditional predictors are still the mainstay in the diagnosis and prognosis of CVD events, increasing studies have focused on exploring the ancillary effect of biomarkers for the aspiring of precision. Under which circumstances, soluble ST2 (sST2), lipoprotein-associated phospholipase A2 (Lp-PLA2), myeloperoxidase (MPO), and procalcitonin (PCT) have recently emerged as promising markers in the field of both acute and chronic cardiovascular diseases. Existent clinical studies have demonstrated the significant associations between these markers with various CVD outcomes, which further verified the potentiality of markers in helping risk stratification and diagnostic and therapeutic work-up of patients. The current review article is aimed at illuminating the applicability of these four novels and often neglected cardiac biomarkers in common clinical scenarios, including acute myocardial infarction, acute heart failure, and chronic heart failure, especially in the emergency department. By thorough classification, combination, and discussion of biomarkers with clinical and instrumental evaluation, we hope the current study can provide insights into biomarkers and draw more attention to their importance.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Biomarkers; Cardiovascular Diseases; Early Diagnosis; Gene Expression Regulation; Humans; Interleukin-1 Receptor-Like 1 Protein; Peroxidase; Procalcitonin; Prognosis

Topics: Animals; Biomarkers; Cardiovascular Diseases; Humans; Peroxidase; Prognosis

Myeloperoxidase (MPO) is an immune enzyme found in neutrophils and macrophages. It produces the highly oxidative compound HOCl from H. This article covers the patent literature published on MPO inhibitors from 2013 to 2019, as well as the potential use of these compounds as therapeutics for inflammatory syndromes, especially that plays an important role in the initiation and progression of atherosclerosis.. To date, many MPO inhibitors with different structures have been studied, many of which have prominent inhibitory activities. Furthermore, the specificity of these drugs offers hope for the targeted therapy of inflammatory syndromes. Although many data have proved that MPO can contribute to several chronic inflammatory syndromes, the usefulness of MPO inhibitors in preventing and treating inflammatory disorders is still under investigation.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cardiovascular Diseases; Chronic Disease; Drug Development; Enzyme Inhibitors; Humans; Inflammation; Patents as Topic; Peroxidase

Neutrophil extracellular traps (NETs) significantly contribute to various pathophysiological conditions, including cardiovascular diseases. NET formation in the vasculature exhibits inflammatory and thrombogenic activities on the endothelium. NETs are induced by various stimulants such as exogenous damage-associated molecular patterns (DAMPs). Oxidatively modified low-density lipoprotein (oxLDL) has been physiologically defined as a subpopulation of LDL that comprises various oxidative modifications in the protein components and oxidized lipids, which could act as DAMPs. oxLDL has been recognized as a crucial initiator and accelerator of atherosclerosis through foam cell formation by macrophages; however, recent studies have demonstrated that oxLDL stimulates neutrophils to induce NET formation and enhance NET-mediated inflammatory responses in vascular endothelial cells, thereby suggesting that oxLDL may be involved in cardiovascular diseases through neutrophil activation. As NETs comprise myeloperoxidase and proteases, they have the potential to mediate oxidative modification of LDL. This review summarizes recent updates on the analysis of NETs, their implications for cardiovascular diseases, and prospects for a possible link between NET formation and oxidative modification of lipoproteins.

Topics: Atherosclerosis; Cardiovascular Diseases; Endothelial Cells; Extracellular Traps; Foam Cells; Humans; Lipoproteins; Lipoproteins, LDL; Macrophages; Neutrophils; Oxidation-Reduction; Peroxidase

Myeloperoxidase (MPO) is a member of the superfamily of heme peroxidases that is mainly expressed in neutrophils and monocytes. MPO-derived reactive species play a key role in neutrophil antimicrobial activity and human defense against various pathogens primarily by participating in phagocytosis. Elevated MPO levels in circulation are associated with inflammation and increased oxidative stress. Multiple lines of evidence suggest an association between MPO and cardiovascular disease (CVD) including coronary artery disease, congestive heart failure, arterial hypertension, pulmonary arterial hypertension, peripheral arterial disease, myocardial ischemia/reperfusion-related injury, stroke, cardiac arrhythmia and venous thrombosis. Elevated MPO levels are associated with a poor prognosis including increased risk for overall and CVD-related mortality. Elevated MPO may signify an increased risk for CVD for at least 2 reasons. First, low-grade inflammation and increased oxidative stress coexist with many metabolic abnormalities and comorbidities and consequently an elevated MPO level may represent an increased cardiometabolic risk in general. Second, MPO produces a large number of highly reactive species which can attack, destroy or modify the function of every known cellular component. The most common MPO actions relevant to CVD are generation of dysfunctional lipoproteins with an increased atherogenicity potential, reduced NO availability, endothelial dysfunction, impaired vasoreactivity and atherosclerotic plaque instability. These actions strongly suggest that MPO is directly involved in the pathophysiology of CVD. In this regard MPO may be seen as a mediator or an instrument through which inflammation promotes CVD at molecular and cellular level. Clinical value of MPO therapeutic inhibition remains to be tested.

Topics: Cardiovascular Diseases; Humans; Inflammation; Oxidative Stress; Peroxidase

Topics: Animals; Autoantigens; Autoimmunity; Biomarkers; Cardiovascular Diseases; Chromatin; Citrullination; Citrulline; Communicable Diseases; Disease Models, Animal; Extracellular Traps; Histones; Humans; Hydrolases; Inflammation; Metabolic Diseases; Neoplasms; Peroxidase; Protein-Arginine Deiminase Type 4; Protein-Arginine Deiminases; Risk Factors; Serine Proteases

Myeloperoxidase (MPO) is a member of the mammalian peroxidase family. It is mainly expressed in neutrophils, monocytes and macrophages. As a catalyzer of reactive oxidative species and radical species formation, it contributes to neutrophil bactericidal activity. Nevertheless MPO invalidation does not seem to have major health consequences in affected individuals. This suggests that MPO might have alternative functions supporting its conservation during evolution. We will review the available data supporting these non-canonical functions in terms of tissue specific expression, function and enzymatic activity. Thus, we discuss its cell type specific expression. We review in between others its roles in angiogenesis, endothelial (dys-) function, immune reaction, and inflammation. We summarize its pathological actions in clinical conditions such as cardiovascular disease and cancer.

Topics: Adaptive Immunity; Animals; Cardiovascular Diseases; Endothelial Cells; Humans; Immunity, Innate; Inflammation; Neoplasms; Neovascularization, Physiologic; Neutrophils; Peroxidase

Chronic kidney disease (CKD) is a worldwide public health problem. Patients with CKD have a number of disorders in the organism, and the presence of oxidative stress and systemic inflammation in these patients is the subject of numerous studies. Chronic inflammation joined with oxidative stress contributes to the development of numerous complications: accelerated atherosclerosis process and cardiovascular disease, emergence of Type 2 diabetes mellitus, development of malnutrition, anaemia, hyperparathyroidism, and so forth, affecting the prognosis and quality of life of patients with CKD. In this review we presented the potential role of the myeloperoxidase enzyme in the production of reactive/chlorinating intermediates and their role in oxidative damage to biomolecules in the body of patients with chronic kidney disease and end-stage renal disease. In addition, we discussed the role of modified lipoprotein particles under the influence of prooxidant MPO intermediates in the development of endothelial changes and cardiovascular complications in renal failure.

Topics: Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dyslipidemias; Humans; Hypoalbuminemia; Inflammation; Oxidative Stress; Peroxidase; Reactive Nitrogen Species; Reactive Oxygen Species; Renal Insufficiency, Chronic

Myeloperoxidase (MPO), a heme protein released by leukocytes, is one of the most widely studied during the last decades molecule that plays a crucial role in inflammation and oxidative stress in the cellular level. It has become increasingly recognized that MPO performs a very important role as part of the innate immune system through the formation of microbicidal reactive oxidants, whilst it affects the arterial endothelium with a number of mechanisms that include modification of net cellular cholesterol flux and impairment of Nitric Oxide (NO)-induced vascular relaxation. In that way, MPO is implicated into both the formation and propagation of atheromatosis and there is substantial evidence that it also promotes ischemia through destabilization of the vulnerable plaque. Numerous studies have added information on the notion that MPO and its oxidant products are part of the inflammatory cascade initiated by endothelial injury and they are significantly overproduced at the site of arterial inflammation. Subsequent studies achieved quantification of this observation showing significant elevations of the systemic levels of MPO in a wide spectrum of cardiovascular disease scenarios with acute coronary syndromes and heart failure being the most studied. This review highlights key-aspects of MPO's pathophysiological properties and summarizes the role of MPO as a diagnostic and prognostic tool for a number of cardiovascular pathologies.

Topics: Animals; Biomarkers; Cardiovascular Diseases; Endothelium, Vascular; Halogens; Heart Failure; Humans; Hydrogen Peroxide; Hypertension; Inflammation; Metabolic Syndrome; Oxidative Stress; Peroxidase; Predictive Value of Tests; Prognosis

The heme-enzyme myeloperoxidase (MPO) is one of the major neutrophil bactericidal proteins and is stored in large amounts inside azurophilic granules of neutrophils. Upon cell activation, MPO is released and extracellular MPO has been detected in a wide range of acute and chronic inflammatory conditions. Recent ADVANCES AND CRITICAL ISSUES: Apart from its role during infection, MPO has emerged as a critical modulator of inflammation throughout the last decade and is currently discussed in the initiation and propagation of cardiovascular diseases. MPO-derived oxidants (e.g., hypochlorous acid) interfere with various cell functions and contribute to tissue injury. Recent data also suggest that MPO itself exerts proinflammatory properties independent of its catalytic activity. Despite advances in unraveling the complex action of MPO and MPO-derived oxidants, further research is warranted to determine the precise nature and biological role of MPO in inflammation.. The identification of MPO as a central player in inflammation renders this enzyme an attractive prognostic biomarker and a potential target for therapeutic interventions. A better understanding of the (patho-) physiology of MPO is essential for the development of successful treatment strategies in acute and chronic inflammatory diseases.

Topics: Cardiovascular Diseases; Humans; Hypochlorous Acid; Infections; Inflammation; Leukocytes; Neutrophils; Peroxidase

The mechanisms that deprive HDL of its cardioprotective properties are poorly understood. One potential pathway involves oxidative damage of HDL proteins by myeloperoxidase (MPO) a heme enzyme secreted by human artery wall macrophages. Mass spectrometric analysis demonstrated that levels of 3-chlorotyrosine and 3-nitrotyrosine - two characteristic products of MPO - are elevated in HDL isolated from patients with established cardiovascular disease. When apolipoprotein A-I (apoA-I), the major HDL protein, is oxidized by MPO, its ability to promote cellular cholesterol efflux by the membrane-associated ATP-binding cassette transporter A1 (ABCA1) pathway is diminished. Biochemical studies revealed that oxidation of specific tyrosine and methionine residues in apoA-I contributes to this loss of ABCA1 activity. Another potential mechanism for generating dysfunctional HDL involves covalent modification of apoA-I by reactive carbonyls, which have been implicated in atherogenesis and diabetic vascular disease. Indeed, modification of apoA-I by malondialdehyde (MDA) or acrolein also markedly impaired the lipoprotein's ability to promote cellular cholesterol efflux by the ABCA1 pathway. Tandem mass spectrometric analyses revealed that these reactive carbonyls target specific Lys residues in the C-terminus of apoA-I. Importantly, immunochemical analyses showed that levels of MDA-protein adducts are elevated in HDL isolated from human atherosclerotic lesions. Also, apoA-I co-localized with acrolein adducts in such lesions. Thus, lipid peroxidation products might specifically modify HDL in vivo. Our observations support the hypotheses that MPO and reactive carbonyls might generate dysfunctional HDL in humans. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).

Topics: Amino Acid Motifs; Animals; Apolipoprotein A-I; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Cardiovascular Diseases; Cholesterol; Halogenation; Humans; Inflammation; Lipoproteins, HDL; Macrophages; Oxidants; Oxidation-Reduction; Peroxidase

High density lipoprotein (HDL) has many properties, which contribute to its atheroprotective role. However, some recent clinical trials have identified subjects with the progression of atherosclerosis despite normal levels of HDL cholesterol. This raises the question if all subfractions of HDL have the same properties. Moreover, recent investigations have shown that both acute and chronic inflammation may lead to structural and functional changes of HDL, which render the particles proinflammatory. Although therapeutic agents that increase HDL levels are now quite well established it is not clear whether they influence HDL quality. We review the current state of knowledge on the properties of HDL and factors/therapeutic agents which may restrain the transformation of normal HDL into dysfunctional HDL.

Topics: Animals; Apolipoproteins; Azetidines; Cardiovascular Diseases; Cholesterol Ester Transfer Proteins; Cholesterol, HDL; Ezetimibe; Fibric Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Niacin; Peroxidase; Thiazolidinediones

Accumulation of low-density lipoprotein (LDL)-derived cholesterol by artery wall macrophages triggers atherosclerosis, the leading cause of cardiovascular disease. Conversely, high-density lipoprotein (HDL) retards atherosclerosis by promoting cholesterol efflux from macrophages by the membrane-associated ATP-binding cassette transporter A1 (ABCA1) pathway. HDL has been proposed to lose its cardioprotective effects in subjects with atherosclerosis, but the underlying mechanisms are poorly understood. One potential pathway involves oxidative damage by myeloperoxidase (MPO), a heme enzyme secreted by human artery wall macrophages. We used mass spectrometry to demonstrate that HDL isolated from patients with established cardiovascular disease contains elevated levels of 3-chlorotyrosine and 3-nitrotyrosine, two characteristic products of MPO. When apolipoprotein A-I (apoA-I), the major HDL protein, was oxidized by MPO, its ability to promote cellular cholesterol efflux by ABCA1 was impaired. Moreover, oxidized apoA-I was unable to activate lecithin:cholesterol acyltransferase (LCAT), which rapidly converts free cholesterol to cholesteryl ester, a critical step in HDL maturation. Biochemical studies implicated tyrosine chlorination and methionine oxygenation in the loss of ABCA1 and LCAT activity by oxidized apoA-I. Oxidation of specific residues in apoA-I inhibited two key steps in cholesterol efflux from macrophages, raising the possibility that MPO initiates a pathway for generating dysfunctional HDL in humans.

Topics: Animals; Cardiovascular Diseases; Humans; Lipoproteins, HDL; Oxidative Stress; Peroxidase

Myeloperoxidase (MPO) is an enzyme found in myeloid cells, particularly in neutrophils, and to a lesser extent in monocytes and tissue macrophages. MPO plays an important role in the host defense against bacteria and viruses. Since MPO is also an important enzyme in the inflammatory process, and inflammation is a key component in the development and progression of atherosclerotic and other forms of cardiovascular disease, there is ongoing interest in the use of MPO as a biomarker in different fields of cardiology. We aimed to review the current state of literature regarding the role of MPO in cardiovascular disease, especially highlighting the practical implications of the fast growing data from clinical studies.

Topics: Cardiology; Cardiovascular Diseases; Coronary Artery Disease; Disease Progression; Heart Failure; Humans; Inflammation; Lipoproteins, LDL; Macrophages; Monocytes; Neutrophils; Peroxidase

Inflammation and oxidative stress are associated with atherosclerosis. Myeloperoxidase (MPO) is linked to both inflammation and oxidative stress by its location in leukocytes and its role in catalyzing the formation of oxidizing agents. Recent evidence suggests that MPO activity precipitates atherogenesis. Measurement of MPO in plasma may therefore contribute to cardiovascular disease (CVD) risk stratification.. Cross-sectional studies, case-control studies, and prospective-cohort studies investigating the relation between MPO and CVD have been evaluated. Differences in study populations, sample materials, sample handling, and assays were ascertained. Potential causal mechanisms linking MPO to accelerated atherosclerosis are discussed here. A majority of studies indicate that measurement of MPO in plasma was associated with improved CVD risk stratification above and beyond risk stratification results obtained with markers used in routine clinical practice. However, comparison of these epidemiological studies with regard to MPO and outcome is hampered because the reported MPO concentration depends on the assay method, sampling material, and preanalytical and analytical procedures. The link between MPO and CVD can, at least partly, be explained by MPO-dependent oxidation of LDL and HDL, subsequently leading to cholesterol accumulation in the arterial wall. Furthermore, MPO may reduce the bioavailability of nitric oxide, resulting in endothelial dysfunction. Finally, MPO destabilizes atherosclerotic plaques.. Increasing evidence suggests that MPO is causally linked to atherosclerosis and its measurement may improve CVD risk estimation. Before MPO can be used in routine clinical practice, however, standardization of sampling and laboratory procedures is needed.

Topics: Atherosclerosis; Biomarkers; Cardiovascular Diseases; Epidemiologic Studies; Humans; Oxidation-Reduction; Peroxidase; Risk Factors

The use of cardiac biomarkers in the intensive care setting is gaining increasing popularity. There are several reasons for this increase: there is now the facility for point-of-care biomarker measurement providing a rapid diagnosis; biomarkers can be used as prognostic tools; biomarkers can be used to guide therapy; and, compared with other methods such as echocardiography, the assays are easier and much more affordable. Two important characteristics of the ideal biomarker are disease specificity and a linear relationship between the serum concentration and disease severity. These characteristics are not present, however, in the majority of biomarkers for cardiac dysfunction currently available. Those clinically useful cardiac biomarkers, which naturally received the most attention, such as troponins and B-type natriuretic peptide, are not as specific as was originally thought. In the intensive care setting, it is important for the user to understand the degree of specificity of these biomarkers and that the interpretation of the results should always be guided by other clinical information. The present review summarizes the available biomarkers for different cardiac conditions. Potential biomarkers under evaluation are also briefly discussed.

Topics: Biomarkers; CA-125 Antigen; Cardiovascular Diseases; CD40 Ligand; Choline; Creatine Kinase, MB Form; Fatty Acid Binding Protein 3; Fatty Acid-Binding Proteins; Humans; Intensive Care Units; Interleukins; Myocardium; Natriuretic Peptide, Brain; Necrosis; Peroxidase; Point-of-Care Systems; Sepsis; Serum Albumin; Troponin; Urocortins

The cellular injury that results from irreversible ischemia leads to the alteration of tissue function responsible for the phenomenon that we call left ventricular remodeling. Oxidative stress and inflammation are key elements of this process; in mice as in humans, elevation of markers of inflammation at the time of myocardial infarction (MI) is a predictor of the development of ischemic myopathy and of adverse clinical outcomes. Several leukocyte-derived enzyme systems are responsible for the release of oxidizing agents into the myocardium after ischemic injury and provide a means of better understanding MI. By identifying the oxidation products present after inflammation, the responsible leukocyte-generating oxidant systems can be elucidated. Interestingly, a key leukocyte-derived marker, myeloperoxidase (MPO), was formerly measured routinely by older-generation hematology analyzers. Patients with lower levels of MPO were noted to be at lower risk for untoward cardiovascular events, suggesting that humans are more genomically "hardwired" than previously thought. Studies with genetic knockout mice confirm the importance of these leukocyte-generated oxidants in the pathophysiologic consequences of ischemia. This clearly affects the anatomic extent of damage, the hemodynamic consequences, and ultimately, the clinical correlates and potential outcomes. An understanding of these oxidative processes and their relation to inflammation will be extremely useful in the development and understanding of potential therapeutic agents.

Topics: Animals; Antioxidants; Cardiovascular Diseases; Humans; Inflammation; Leukocytes; Lipid Peroxidation; Myocardial Infarction; Oxidants; Oxidative Stress; Peptide Hydrolases; Peroxidase; Ventricular Remodeling

Over the last decade, significant data has accumulated to suggest that biomarkers of oxidative stress accurately reflect the presence of cardiovascular risk factors, the extent of cardiovascular disease (CVD), and cardiovascular outcomes. This cumulative evidence has supported the approval of several of these biomarkers for clinical applications. For example, lipoprotein-associated phospholipase A(2) (Lp-PLA2) and myeloperoxidase (MPO) mass assays are now available to assist clinicians in determining overall cardiovascular risk in asymptomatic patients thought to be at increased risk or in patients with cardiovascular symptoms. However, it is not yet firmly established whether and to what extent these oxidative biomarkers reflect changes in response to therapeutic interventions. This article reviews the latest data on MPO, isoprostanes, oxidized low-density lipoprotein, oxidized phospholipids, and Lp-PLA2 biomarker assays, and it assesses their role in reflecting therapeutic interventions to treat CVD.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Anti-Inflammatory Agents; Antioxidants; Cardiovascular Diseases; Humans; Isoprostanes; Lipid Peroxidation; Oxidative Stress; Peroxidase

Several emerging plasma biomarkers may ultimately prove useful in risk stratification and prognosis of cardiovascular disease. The clinical utility of these biomarkers will depend on their ability to provide a reflection of the underlying atherosclerotic burden or activity; the ability to provide reliable, accurate, and cost-effective information; and the ability to predict future events. High-sensitivity C-reactive protein (hs-CRP) fulfills many, if not all, of these criteria, and blood levels of hs-CRP are now commonly used in clinical practice to improve vascular risk prediction in primary and secondary prevention across all levels of low-density lipoprotein-cholesterol (LDL-C), all levels of the Framingham Risk Score, and all levels of metabolic syndrome. High-sensitivity C-reactive protein may also have clinical relevance as an adjunct to LDL-C for both the targeting and monitoring of statin therapy. Accumulating evidence suggests that several other selected emerging biomarkers may also potentially prove useful in the diagnosis and prognosis of cardiovascular disease. Specifically, data are accumulating on the potential clinical utility of lipoprotein-associated lipoprotein-associated phospholipase A2, myeloperoxidase, oxidized LDL, lipoprotein (a), isoprostanes, and small, dense LDL. This review focuses on hs-CRP and these emerging plasma biomarkers, and their potential diagnostic and prognostic utility in cardiovascular disease. Plasma biomarkers that reflect the clinical potential of atherothrombotic disease may allow more precise risk stratification and prognostication in high-risk populations, and perhaps earlier diagnosis and intervention in patients at risk for or with occult cardiovascular disease.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Cholesterol, LDL; Humans; Isoprostanes; Lipoproteins, LDL; Peroxidase; Phospholipases A; Phospholipases A2; Risk Assessment

The cardioprotective effect of high-density lipoprotein (HDL) is thought to involve, in part, the membrane-associated ATP-binding cassette transporter ABCA1, which clears cholesterol from lipid-laden macrophages in the artery wall. If HDL is unable to interact with this transporter because of oxidative damage, cholesterol clearance is impaired. Important insights into the mechanisms that oxidize proteins in the human artery wall have come from the mass spectrometric (MS) detection of oxidized amino acids that result from specific reaction pathways. Recent MS studies indicate that HDL isolated from patients with cardiovascular disease contains elevated levels of 3-chlorotyrosine and 3-nitrotyrosine, which are two characteristic products of myeloperoxidase (MPO), a heme enzyme secreted by macrophages. MPO-dependent chlorination of apolipoprotein A-I (apoA-I), the major HDL protein, impairs its ability to remove excess cellular cholesterol by the ABCA1 pathway. Tandem MS analysis of apoA-I has demonstrated that this loss of activity is associated with methionine oxidation and chlorination of a single tyrosine residue. Analysis of mutated forms of apoA-I has implicated lysine residues in the regiospecific chlorination of tyrosine. It is further suggested that the tyrosine chlorination and methionine oxidation of apoA-I impairs ABCA1 transport activity. The crystal structure of lipid-free apoA-I suggests a potential mechanism for rendering this protein dysfunctional. Collectively, these observations indicate that MPO oxidatively damages HDL in humans and suggest that oxidation of specific amino acid residues in apoA-I may contribute to atherogenesis by impairing cholesterol efflux from macrophages.

Topics: Apolipoprotein A-I; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Cardiovascular Diseases; Humans; Lipoproteins, HDL; Oxidation-Reduction; Peroxidase

Myeloperoxidase (MPO) is a leukocyte-derived enzyme that catalyzes the formation of a number of reactive oxidant species. In addition to being an integral component of the innate immune response, evidence has emerged that MPO-derived oxidants contribute to tissue damage during inflammation. MPO-catalyzed reactions have been attributed to potentially proatherogenic biological activities throughout the evolution of cardiovascular disease, including during initiation, propagation, and acute complication phases of the atherosclerotic process. As a result, MPO and its downstream inflammatory pathways represent attractive targets for both prognostication and therapeutic intervention in the prophylaxis of atherosclerotic cardiovascular disease.

Topics: Cardiovascular Diseases; Humans; Leukocytes; Peroxidase; Vasculitis

Cardiovascular disease is common in patients with chronic kidney disease (CKD). As renal function fails, many patients become progressively malnourished, as evidenced by reduced levels of albumin, prealbumin, and transferrin. Malnourished patients have increased levels of C reactive protein (CRP), interleukin-6 (IL-6), and concomitant cardiovascular disease when they reach end stage. Many diseases that cause CKD, diabetes, and hypertension are also associated with cardiovascular disease. Thus the direct effect of renal failure per se directly contributing to the inflammation-malnutrition-atherosclerosis paradigm is not completely established in early stages of CKD. Some aspects of progressive renal failure, however, cause changes in plasma composition and endothelial structure and function that favor vascular injury. As renal function fails, hepatic apo A-I synthesis decreases and HDL levels fall. HDL is an important antioxidant and defends the endothelium from the effects of cytokines. Inflammation causes further structural and functional abnormalities in HDL. Apolipoprotein C III (apo C III), a competitive inhibitor of lipoprotein lipase is increased in CKD. Serum triglyceride levels increase as a result of accumulation of intermediate-density lipoprotein (IDL) comprising VLDL and chylomicron remnants. These impede vascular relaxation and are associated with cardiovascular disease. Activation of the renin angiotensin axis is a component of many renal diseases and adaptation to loss of renal mass. Angiotensin II (AngII) activates NADPH oxidases, leading to production of the superoxide anion and decreased availability of nitric oxide (NO), further impairing vascular function. H(2)O(2), produced as a consequence of superoxide dismutation, stimulates vascular cell proliferation and hypertrophy. Leukocyte-derived myeloperoxidase functions as an "NO Oxidase" in the inflamed vasculature and contributes to decreased NO bioavailability and compromised vascular reactivity. The changes in lipoprotein composition and structure as well as AngII-mediated alterations in endothelial function amplify the effect of subsequent inflammatory events.

Topics: Angiotensins; Animals; Cardiovascular Diseases; Disease Progression; Humans; Inflammation; Kidney Failure, Chronic; Lipoproteins; NADPH Oxidases; Oxidative Stress; Peroxidase; Risk Factors; Severity of Illness Index

Myeloperoxidase, an abundant leukocyte protein that generates reactive oxidant species, is present and catalytically active within atherosclerotic lesions. Numerous lines of evidence suggest mechanistic links between myeloperoxidase, inflammation and both acute and chronic manifestations of cardiovascular disease.. Myeloperoxidase generates reactive oxidant species as part of its function in innate host defense mechanisms. The reactive species formed, however, may also damage normal tissues, contributing to inflammatory injury. Recent studies suggest that MPO-generated oxidants participate in multiple processes relevant to cardiovascular disease development and outcomes, including induction of foam cell formation, endothelial dysfunction, development of vulnerable plaque, and ventricular remodeling following acute myocardial infarction. Of note, measurements of myeloperoxidase mass and activity may be useful in cardiac risk stratification, both for chronic disease assessment, as well as in identification of patients at risk in the acute setting.. The inflammatory protein myeloperoxidase is present, active and mechanistically poised to participate in the initiation and progression of cardiovascular disease. The many links between myeloperoxidase, oxidation and cardiovascular disease suggest this leukocyte protein may have clinical utility in risk stratification for cardiovascular disease status and outcomes.

Topics: Animals; Biomarkers; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Lipid Peroxidation; Oxidative Stress; Peroxidase; Risk Assessment

Inflammatory processes are now recognized to play a central role in the pathogenesis of atherosclerosis and its complications. Plasma levels of several markers of inflammation have been found to be associated with future cardiovascular risk in a variety of clinical settings. These markers include cell adhesion molecules, cytokines, pro-atherogenic enzymes and C-reactive protein (CRP). Initially thought of as an inactive downstream marker of the inflammatory cascade, emerging evidence suggests that CRP may be directly involved in atherogenesis, and that arterial plaque can produce CRP, independent of traditional hepatic pathways. In addition to being a strong predictor of future cardiovascular risk amongst patients presenting with acute coronary syndromes, numerous studies have found that baseline levels of CRP are associated with risk of future myocardial infarction, stroke, peripheral vascular disease and cardiovascular death amongst apparently healthy populations. The combination of measurement of a marker of inflammation with lipid testing may improve upon risk stratification based on lipid testing alone, and intensification of programmes for exercise, weight loss, and smoking cessation is recommended for those with elevated CRP levels. Further trials are needed to confirm the potential benefits of statins amongst individuals with elevated CRP levels.

Topics: Animals; Arteriosclerosis; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Case-Control Studies; Cell Adhesion Molecules; Cohort Studies; Cytokines; Exercise; Female; Humans; Hyperlipidemias; Hypolipidemic Agents; Inflammation; Inflammation Mediators; Interleukin-6; Lipids; Male; Mice; Mice, Knockout; Peroxidase; Prognosis; Prospective Studies; Risk; Risk Assessment; Risk Factors; Smoking; Weight Loss

Myeloperoxidase (MPO) is a glycoprotein released by activated polymorphonuclear neutrophils, which takes part in the defense of the organism through production of hypochlorous acid (HOCl), a potent oxidant. Since the discovery of MPO deficiency, initially regarded as rare and restricted to patients suffering from severe infections, MPO has attracted clinical attention. The development of new technologies allowing screening for this defect has permitted new advances in the comprehension of underlying mechanisms. Apart from its implications for host defense, the expression of MPO restricted to myeloid precursors makes MPO mRNA a good marker of acute myeloid leukemia. In addition, during the last few years, involvement of MPO has been described in numerous diseases such as atherosclerosis, lung cancer, Alzheimer's disease and multiple sclerosis. Both strong oxidative activity and MPO genetic polymorphism have been involved. This review summarizes the broad range of diseases involving MPO and points out the possible use of this protein as a new clinical marker and a future therapeutic target.

Topics: Alzheimer Disease; Cardiovascular Diseases; Drug Delivery Systems; Humans; Immune System Diseases; Multiple Sclerosis; Neoplasms; Neutrophils; Peroxidase

Topics: Biomarkers; Blood Proteins; C-Reactive Protein; Cardiovascular Diseases; Dose-Response Relationship, Drug; Elapid Venoms; Humans; Hypochlorous Acid; Inflammation; Kidney Failure, Chronic; Macrophage Activation; N-Formylmethionine Leucyl-Phenylalanine; Oxidation-Reduction; Oxidative Stress; Peroxidase; Phagocytes; Phagocytosis; Renal Dialysis; Sulfhydryl Compounds; Tetradecanoylphorbol Acetate; Uremia

Myeloperoxidase activity can contribute to impaired vascular endothelial function and fibrosis in chronic inflammation-related cardiovascular disease. Here, we investigated the safety, tolerability and pharmacokinetics of the myeloperoxidase inhibitor, AZD4831.. In this randomized, single-blind, placebo-controlled, phase I, first-in-human study, healthy men in five sequential cohorts were randomized 3:1 to receive a single oral dose of AZD4831 (5, 15, 45, 135 or 405 mg) or placebo, after overnight fasting. After at least 7 days' washout, one cohort additionally received AZD4831 45 mg after a high-calorie meal.. AZD4831 was generally well tolerated, rapidly absorbed, had a long plasma half-life and lowered uric acid concentrations after single oral doses in healthy men. These findings support the further clinical development of AZD4831.

Topics: Administration, Oral; Adult; Area Under Curve; Cardiovascular Diseases; Drug Administration Schedule; Enzyme Inhibitors; Half-Life; Healthy Volunteers; Humans; Male; Middle Aged; Peroxidase; Placebos; Pyrimidines; Pyrroles; Single-Blind Method; Uric Acid; Young Adult

Although existing research highlights the relationship of OSA and cardiovascular disease, the effect of OSA treatment on cardiovascular biomarkers remains unclear. We evaluated the effect of OSA treatment on oxidative stress/inflammation measures.. We conducted a parallel, randomized controlled trial in moderate to severe OSA (apnea-hypopnea index ≥ 15) patients to examine effects of 2-month CPAP vs sham-CPAP on the primary outcome of oxidative stress/inflammation (F2-isoprostanes: ng/mg) and myeloperoxidase: pmol/L) and secondary oxidative stress measures. Exploratory secondary analyses included vascular and systemic inflammation markers. Linear models adjusted for baseline values examined effect of CPAP on biomarker change (least squares means, 95% CI) including secondary stratified analyses examining CPAP adherence and degree of hypoxia.. Of 153 participants, 76 were randomized to CPAP and 77 to sham-CPAP. In an intent-to-treat analyses, no significant change was observed in the sham and CPAP groups respectively: F2-isoprostanes (-0.02 [-0.12 to 0.10] vs -0.08 [-0.18 to 0.03]) or myeloperoxidase (-3.33 [-17.02 to 10.37] vs -5.15 [-18.65 to 8.35]), nor other oxidative markers; findings that persisted in analyses stratified by adherence and hypoxia. Exploratory analyses revealed percentage reduction of soluble IL-6 receptor (ng/mL) levels (-0.04 [-0.08 to -0.01] vs 0.02 [-0.02 to 0.06], P = .019) and augmentation index (%) (-6.49 [-9.32 to -3.65] vs 0.44 [-2.22 to 3.10], P < .001) with CPAP compared with sham, respectively.. In moderate to severe OSA, 2-month CPAP vs sham did not reduce oxidative stress despite consideration of a broad range of measures, positive airway pressure adherence, and hypoxia burden. These findings suggest that nonoxidative stress pathways primarily modulate OSA-related cardiovascular consequences.. ClinicalTrials.govNCT00607893.

Topics: Adult; Biomarkers; Cardiovascular Diseases; Continuous Positive Airway Pressure; F2-Isoprostanes; Female; Humans; Inflammation; Male; Middle Aged; Oxidative Stress; Peroxidase; Receptors, Interleukin-6; Risk Factors; Sleep Apnea, Obstructive; Statistics as Topic

The aim of this study was to evaluate the endothelial function, systemic inflammatory biomarkers and subgingival microbial profile associations in patients with and without periodontal disease.. Forty-four patients, half with chronic moderate to severe periodontitis (cases) and half gingivitis and incipient periodontitis (controls) were recruited. Anthropometric, clinical, biochemical parameters, endothelial function, subgingival microbiota, and eight plasma biomarkers of cardiovascular disease were assessed in both groups.. Both groups were comparable in anthropometric parameters, blood pressure, and number of positive metabolic syndrome components. Univariate analyses demonstrated significantly higher plasma levels of E-selectin (64.5 ± 30.9 vs 43.8 ± 22.2; P = 0.026) and myeloperoxidase (MPO) (103 ± 114.5 vs 49.1 ± 35.6; P = 0.032) in cases than controls. In addition, significantly higher levels of E-selectin, MPO and ICAM-1 were found in periodontitis patients after adjustment by age and waist circumference. Red complex microorganisms were more frequently detected by culture and polymerase chain reaction in patients with severe to moderate periodontitis.. Subgingival red complex bacteria and important cardiovascular risk markers were increased in untreated chronic moderate to severe periodontitis cases. Periodontitis seems to be associated with systemic inflammation that could increase the risk of cardiovascular events. The causal relation between periodontal infections and cardiovascular disease requires further research.

Topics: Adult; Analysis of Variance; Bacteria; Biomarkers; Cardiovascular Diseases; Case-Control Studies; Chronic Periodontitis; Colombia; E-Selectin; Female; Gingivitis; Humans; Intercellular Adhesion Molecule-1; Male; Peroxidase; Polymerase Chain Reaction; Reactive Oxygen Species; Risk Factors

There is considerable interest in pharmacogenetic and molecular biomarkers. Our aim was to evaluate the effects of enalapril/lercanidipine combination on some emerging biomarkers for cardiovascular risk stratification of hypertensive patients, such as lipoprotein(a) [Lp(a)], soluble advanced glycation end products (sRAGE), soluble CD40 ligand (sCD40L) and serum myeloperoxidase (MPO).. Three hundred and forty-five patients were enrolled in this randomized, double-blind, clinical trial: 120 hypertensive patients were randomized to enalapril 20 mg, 110 to lercanidipine 10 mg and 115 to enalapril/lercanidipine 20/10 mg fixed combination. We measures the following markers at baseline and after 6, 12, 18 and 24 months: blood pressure, fasting plasma glucose (FPG), lipid profile, Lp(a), sRAGE, sCD40L and MPO.. There was a decrease in blood pressure in all groups compared with baseline, even if, as expected, enalapril/lercanidipine combination was more effective in reducing blood pressure compared with the monotherapies. No variations in lipid profile or FPG were recorded in any of the groups. Lercanidipine, but not enalapril, improved Lp(a) levels compared with baseline. The combination enalapril/lercanidipine improved it more than the single therapies. All treatments increased sRAGE levels, and decreased sCD40L and MPO, with a better effect seen with the enalapril/lercanidipine combination compared with single monotherapies.. The combination enalapril/lercanidipine seems to be better than the single monotherapies in reducing not only blood pressure, but also the levels of some emerging biomarkers, potentially useful for cardiovascular risk stratification of hypertensive patients.

Topics: Angiotensin-Converting Enzyme Inhibitors; Biomarkers; Blood Glucose; Blood Pressure; Calcium Channel Blockers; Cardiovascular Diseases; CD40 Ligand; Dihydropyridines; Double-Blind Method; Drug Combinations; Enalapril; Female; Humans; Hypertension; Lipids; Male; Middle Aged; Peroxidase; Risk Factors

Statins are thought to have anti-atherogenic effects beyond cholesterol lowering. One such mechanism may involve reduction of oxidative stress. The aim of our study was to investigate and to compare the oxidative stress lowering capacity of atorvastatin with that of simvastatin in patients at high risk for cardiovascular disease using conventional markers and sensitive markers measured by highly specific techniques such as liquid chromatography tandem mass spectrometry.. We included 30 statin-naive patients with diabetes mellitus, and/or obesity, and/or hypertension (12 male, 18 female, mean age 44.8±11.1 years), and randomised them to receive either atorvastatin 10 mg or simvastatin 40 mg daily to obtain an equimolar cholesterol reduction. Blood and urine samples were obtained at baseline and at 1, 6 and 12 weeks.. Low-density lipoprotein (LDL) cholesterol and coenzyme Q10 decreased significantly in both groups. Simvastatin caused a faster initial LDL cholesterol lowering than atorvastatin (p=0.01), but the overall effect after 12 weeks of atorvastatin and simvastatin was similar. Plasma myeloperoxidase and malondialdehyde did not change during the study period in the two groups. Urinary F2-isoprostanes decreased gradually and significantly in the atorvastatin group but not in the simvastatin group, but the between-group difference was not significant. Urinary 8-hydroxy-2-deoxyguanosine did not change in the two groups.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Atorvastatin; Cardiovascular Diseases; Cholesterol, LDL; Deoxyguanosine; F2-Isoprostanes; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Peroxidase; Pyrroles; Simvastatin; Ubiquinone

Myeloperoxidase (MPO) is a marker of plaque vulnerability and a mechanistic bridge between inflammation and cardiovascular disease, and thus is a suitable target for therapeutic strategy against cardiovascular disease.. Since hypercholesterolemia is associated with atherosclerosis and inflammation, we tested whether MPO serum levels were up-regulated in Familial Hypercholesterolemia (FH) and whether acute reduction of total cholesterol (TC) would also reduce MPO concentration. FH subjects undergoing LDL-apheresis (LDL-A) treatment are a paradigmatic clinical model where TC rapidly plunges from extremely high to extremely low levels after selective LDL removal, and then spontaneously rebounds to baseline conditions. This clinical setting allows multiple intra-patient observations at different plasma TC concentrations. We measured MPO levels in serum by ELISA tests, and in peripheral leukocytes by immunofluorescence, to learn whether they were affected by the changes in TC levels. Serum MPO was measured before and serially up to the 14th day following LDL-A.. In both serum and peripheral leukocytes, MPO concentrations were i) higher than in sex- and age-matched healthy controls (p < 0.01); ii) decreased with TC reduction; iii) parallel with TC time course; iv) correlated with plasma TC. At regression analysis, plasma TC was the only variable considered that influenced MPO serum levels (β 0.022 ± 0.010, p < 0.0001).. In FH the MPO serum levels were modulated through changes in the TC concentrations carried out by LDL-A. Further study is needed to determine whether reduced MPO levels obtained by LDL-A could have any therapeutic impact.

Topics: Acute-Phase Proteins; Blood Component Removal; Cardiovascular Diseases; Cholesterol; Enzyme-Linked Immunosorbent Assay; Female; Fluoroimmunoassay; Humans; Hyperlipoproteinemia Type II; Lipoproteins, LDL; Male; Neutrophils; Peroxidase; Risk Factors; Time Factors

Genetic variations in the NADPH/MPO system in chronic kidney disease (CKD) patients might lead to altered activity of these enzymes, and thus to altered risk for oxidative stress (OS) and cardiovascular disease (CVD). We evaluated the impact of 242C/T CYBA and -463G/A MPO polymorphisms on OS and CVD mortality in stage 5 CKD patients starting dialysis. Two hundred and fifty-seven patients were genotyped using Pyrosequencing. Plasmalogen [dimethylacetal (DMA) 16/C16:0] was used as OS marker. CVD was assessed from patient history and clinical symptoms. Prevalence of CVD was higher (35%) in GG patients (MPO) compared to AG (26%) and AA (0%) patients (p < 0.01). Patients with CC genotype (CYBA) had lower levels of DMA 16/C16:0 (ratio 0.071 +/- 0.003) compared to TT patients (0.089 +/- 0.006; p < 0.05). These patients also had increased CVD mortality compared to CT and TT patients (chi(2) 2.19; p < 0.05). We conclude that genetic variations in the NADPH/MPO system are associated with OS, presence of CVD and CVD-related mortality in CKD patients.

Topics: Adult; Aged; Cardiovascular Diseases; Female; Humans; Male; Middle Aged; NADPH Oxidases; Oxidative Stress; Peroxidase; Polymorphism, Genetic; Renal Insufficiency, Chronic

LDL apheresis is an extracorporal modality to lower the concentration of atherogenic lipoproteins, e.g., LDL cholesterol. We compared two recently introduced whole-blood LDL apheresis systems inpatients with hypercholesterolemia in a randomized cross-over trial with respect to their effects on lipoproteins as well as on other cardiovascular risk markers. Six patients (4 women, 2 men, median age 62.5 years, median BMI 25.9 kg/m(2)) on regular LDL apheresis were randomly assigned to receive six weekly treatments with either DALI (Fresenius) or Liposorber D (Kaneka). After 6 weeks, the patients were switched to the other device (again six weekly treatments). Blood was drawn before and immediately after LDL apheresis at three time points (last regular apheresis before the study; after six treatments with DALI and after six treatments with Liposorber D). LDL cholesterol concentration before the sixth apheresis (DALI 129 mg/dL, Liposorber D 132 mg/dL) as well as LDL cholesterol reduction during the sixth apheresis (DALI 68.3% and Liposorber D 68.4%) were similar with the two systems. CRP and fibrinogen concentrations were lower but interleukin-6, myeloperoxidase, and resistin concentrations were higher after the last Liposorber treatment compared with DALI (P < 0.05, respectively). No differences were observed concerning adiponectin, ghrelin, and PYY levels. In conclusion, both devices were highly effective in eliminating atherogenic lipoproteins. CRP and fibrinogen were better eliminated with Liposorber D. However, following Liposorber D, interleukin-6 levels were higher than after DALI possibly indicating an increased inflammatory activation.

Topics: Adiponectin; Aged; Blood Component Removal; C-Reactive Protein; Cardiovascular Diseases; Cardiovascular System; Cholesterol, LDL; Cross-Over Studies; Female; Humans; Hypercholesterolemia; Interleukins; Male; Middle Aged; Peroxidase; Risk Factors

Atherosclerotic cardiovascular disease and tooth infection are common in primary care, and both significantly reduce quality of life. Our study aimed to examine signs of vascular inflammation associated with loss of tooth vitality before and after a single tooth extraction.. An observational cohort study was performed with adults who had a nonvital tooth and an indicated desire for tooth extraction. Concentrations of total cholesterol, high-density lipoprotein-cholesterol, high-sensitivity C-reactive protein (hs-CRP), myeloperoxidase (MPO), and troponin T were measured in venous blood serum or plasma at baseline and 6-weeks after tooth extraction.. Circulating hs-CRP levels were > 3 mg/dL in 15 participants (68.2%) and MPO levels were > 350 pmol/L in 9 (40.9%) of 22 participants at baseline. After tooth extraction (n = 18), MPO levels decreased significantly compared with baseline (P < .00006) and hs-CRP levels moved directionally downward. The response rate for MPO was 88.9% (confidence interval: 65.1%-98.6%) from visit 1 to visit 2. Those with high MPO levels at baseline demonstrated larger reductions in MPO levels by visit 2 than those with lower baseline MPO levels (r = .81; P < .0001). A total of 13 individuals (72.2%) achieved MPO levels < 350 pmol/L and 11 (61.1%) achieved hs-CRP levels < 3 mg/dL at visit 2. Total cholesterol, high-density lipoprotein-cholesterol, and troponin T levels did not significantly change from visit 1 to visit 2.. A link between dental infection and circulating levels of inflammation was observed, suggesting that oral infection could be a risk factor for atherosclerotic cardiovascular disease.

Topics: Adult; Atherosclerosis; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Cholesterol, HDL; Humans; Inflammation; Peroxidase; Quality of Life; Troponin T

Metal ion-facilitated chemodynamic therapy (CDT) is an emerging method for treating cancer. However, its potential is hindered by its low catalytic performance in weakly acidic tumor microenvironments (TMEs) and the severe toxicity of free metal ions. A new approach to tumor therapy, chemodynamic vascular disruption (CVD), is introduced using metal-free, peroxidase (POD)-mimetic multihydroxylated [70] fullerene (MHF) nanocatalysts. The research shows that MHF contains C···O active sites, as demonstrated by density functional theory (DFT) calculations, and converts H

Topics: Animals; Cardiovascular Diseases; Cell Line, Tumor; Disease Models, Animal; Endothelium, Vascular; Hydrogen Peroxide; Mice; Neoplasms; Peroxidase; Peroxidases; Tumor Microenvironment

Neutrophil extracellular traps (NETs) play important roles in sepsis and deep-seated infections, but whether NET formation correlates with clinical outcomes of patients with streptococcal bloodstream infections (BSIs) is unclear.. We analyzed serum levels of complexes of myeloperoxidase and DNA (MPO-DNA) in patients with streptococcal-BSIs. In vitro assay of NET induction by serum from BSI patients was performed.. MPO-DNA values for the Streptococci-BSI group (n = 59) were significantly higher than those for healthy controls (p < 0.00001) and matched control groups (n = 59, p = 0.004). The rate of higher MPO-DNA levels (>1.87 μg/mL) were higher in abscess-prone streptococcal groups (streptococcus milleri group) (72.2% vs. 52.5%, p = 0.02). For patients with BSIs due to highly infective endocarditis (IE)-prone pathogens, the values of serum MPO-DNA were also higher in patients diagnosed of IE compared to their counterparts (p = 0.009). Notably, serum from patients with leukopenia could induce higher amounts of in vitro NET formation, despite having low MPO-DNA levels, suggesting that NET formation could be influenced by WBC counts. Therefore, we combined WBC counts with MPO-DNA to predict all-cause 30-day mortality in patients with commensal streptococcal-BSIs. The mortality risk was lowest among patients who had neither high MPO-DNA levels nor abnormal WBC counts (p = 0.058). Furthermore, this group of patients also had a favorable composite outcome consisting of major adverse cardiovascular events (MACE) and all-cause mortality (p = 0.026).. Together, these study data suggested that serum MPO-DNA can be a biomarker for predicting a composite outcome consisting of MACE and all-cause mortality in patients with commensal streptococcal-BSIs.

Topics: Bacteremia; Biomarkers; Cardiovascular Diseases; DNA; Extracellular Traps; Humans; Neutrophils; Peroxidase; Sepsis

Metabolic syndrome is a cluster of risk factors for cardiovascular disease afflicting more than 1 billion people worldwide and is increasingly being identified in younger age groups and in socioeconomically disadvantaged settings in the global south. Enteropathogen exposure and environmental enteropathy in infancy may contribute to metabolic syndrome by disrupting the metabolic profile in a way that is detectable in cardiometabolic markers later in childhood. A total of 217 subjects previously enrolled in a birth cohort in Amazonian Peru were monitored annually from ages 2 to 5 years. A total of 197 blood samples collected in later childhood were analyzed for 37 cardiometabolic biomarkers, including adipokines, apolipoproteins, cytokines, which were matched to extant early-life markers of enteropathy ascertained between birth and 2 years. Multivariate and multivariable regression models were fitted to test for associations, adjusting for confounders. Fecal and urinary markers of intestinal permeability and inflammation (myeloperoxidase, lactulose, and mannitol) measured in infancy were associated with later serum concentrations of soluble CD40-ligand, a proinflammatory cytokine correlated with adverse metabolic outcomes. Fecal myeloperoxidase was also associated with later levels of omentin-1. Enteric protozoa exposure showed stronger associations with later cardiometabolic markers than viruses, bacteria, and overall diarrheal episodes. Early-life enteropathy markers were associated with altered adipokine, apolipoprotein, and cytokine profiles later in childhood consistent with an adverse cardiometabolic disease risk profile in this cohort. Markers of intestinal permeability and inflammation measured in urine (lactulose, mannitol) and stool (myeloperoxidase, protozoal infections) during infancy may predict metabolic syndrome in adulthood.

Topics: Adipokines; Apolipoproteins; Biomarkers; Birth Cohort; Cardiovascular Diseases; Child, Preschool; Cytokines; Humans; Inflammation; Intestinal Diseases; Lactulose; Ligands; Mannitol; Metabolic Syndrome; Peroxidase; Peru

Currently there are no established therapies to treat high-risk patients with unstable atherosclerotic lesions that are prone to rupture and can result in thrombosis, abrupt arterial occlusion, and a precipitous infarction. Rather than being stenotic, rupture-prone non-occlusive plaques are commonly enriched with inflammatory cells and have a thin fibrous cap. We reported previously that inhibition of the pro-inflammatory enzyme myeloperoxidase (MPO) with the suicide inhibitor AZM198 prevents formation of unstable plaque in the Tandem Stenosis (TS) mouse model of plaque instability. However, in our previous study AZM198 was administered to animals before unstable plaque was present and hence it did not test the significant unmet clinical need present in high-risk patients with vulnerable atherosclerosis. In the present study we therefore asked whether pharmacological inhibition of MPO with AZM198 can stabilize pre-existing unstable lesions in an interventional setting using the mouse model of plaque instability. In vivo molecular magnetic resonance imaging of arterial MPO activity using bis-5-hydroxytryptamide-DTPA-Gd and histological analyses revealed that arterial MPO activity was elevated one week after TS surgery, prior to the presence of unstable lesions observed two weeks after TS surgery. Animals with pre-existing unstable plaque were treated with AZM198 for one or five weeks. Both short- and long-term intervention effectively inhibited arterial MPO activity and increased fibrous cap thickness, indicative of a more stable plaque phenotype. Plaque stabilization was observed without AZM198 affecting the arterial content of Ly6B.2

Topics: Animals; Atherosclerosis; Cardiovascular Diseases; Disease Models, Animal; Mice; Peroxidase; Plaque, Atherosclerotic

Rheumatoid arthritis is an inflammatory disease with joint manifestations. In the presence of extra-articular manifestations, the morbidity and severity of the disease increase. Glucocorticoid is used as a treatment and may result in side effects related to cardiovascular risk.. This was a cross-sectional study including 59 volunteers with rheumatoid arthritis receiving treatment at a hospital of Campos Gerais that aimed to establish the relation between cardiovascular risk, glucocorticoid treatment and myeloperoxidase in these patients. Subjects were divided into two groups: using (n = 39) and without glucocorticoids (n = 20). They underwent clinical evaluation, physical examination and blood samples were taken. Statistical analysis was performed using Student's t test and Mann-Whitney test. Logistic regression was performed to assess the cardiovascular risk. The significance level was 5% (α = 0.05). Calculations were performed using the Statistical Package for the Social Science version 21.0.. There has been a significant difference between groups in blood glucose values (p = 0.012), which can be explained by the different percentage of diabetic patients in the groups. When assessing cardiovascular risk using the predictors of glucocorticoid dose, time of glucocorticoid use, myeloperoxidase, and C-reactive protein together, these were responsible for significantly predicting this risk (p = 0.015).. A significant relation between the predictor myeloperoxidase alone was also demonstrated (p = 0.037), it may be an important predictor of cardiovascular risk among individuals with rheumatoid arthritis.

Topics: Adult; Aged; Arthritis, Rheumatoid; Blood Glucose; C-Reactive Protein; Cardiovascular Diseases; Cross-Sectional Studies; Dose-Response Relationship, Drug; Female; Glucocorticoids; Heart Disease Risk Factors; Humans; Male; Middle Aged; Peroxidase; Time Factors

To investigate the association between neutrophil activation and cardiovascular risk in gout patients. We hypothesize that neutrophil activation mediates inflammation and therefore takes part in atherogenesis in gout patients.. Patient data were collected from 75 consecutive gout patients participating in the Reade gout cohort Amsterdam. Levels of neutrophil extracellular traps (NETs) and neutrophil activation (calprotectin and peroxidase activity) were analysed by ELISA and fluorimetry in plasma and compared with healthy controls. Markers of neutrophil activation were related to clinical markers of cardiovascular risk, including BMI, smoking, blood pressure, lipid profile and 10 year risk of cardiovascular mortality (EU-SCORE).. Increased levels of NETs were found in gout patients, although increased levels were not associated with cardiovascular risk. However, markers of neutrophil activation, including peroxidase activity correlated with waist:hip ratio (β = 0.33, P < 0.001), cholesterol ratio (β = 0.46, P < 0.005) and triglycerides (β = 0.60, P < 0.001) as well as the 10 year risk of cardiovascular mortality (β = 0.44, P = 0.001). Calprotectin levels were elevated in hypertension (P = 0.005) and diabetes (P = 0.02). Finally, gout patients with high levels of both peroxidase and calprotectin ('neutrophil activation signature') had a markedly elevated cardiovascular risk score (P = 0.001), with 68% of the patients having high cardiovascular risk (odds ratio 2.9, P = 0.03).. We demonstrated elevated levels of neutrophil activation markers, MPO and calprotectin in gout patients as compared with healthy controls. Of note, neutrophil activation markers were associated with several risk factors for cardiovascular disease, including hyperlipidaemia, hypertension and diabetes. Finally, the presence of a neutrophil activation signature was strongly associated with an increased 10 year risk of cardiovascular mortality. Further studies are needed to determine whether gout-specific factors and/or cardiovascular risk factors contribute to the elevated neutrophil activation observed in these patients.

Topics: Body Mass Index; Cardiovascular Diseases; Case-Control Studies; Extracellular Traps; Female; Gout; Heart Disease Risk Factors; Humans; Hypertension; Leukocyte L1 Antigen Complex; Lipids; Male; Middle Aged; Neutrophil Activation; Peroxidase; Smoking; Waist-Hip Ratio

To estimate the levels of myeloperoxidase in various stages of chronic kidney disease, and to correlate them with an inflammatory marker and lipid profile.. The cross-sectional study was conducted at the Biochemistry Department, Basic Medical Sciences Institute, in collaboration with the Nephrology Department, Jinnah Post Graduate Medical Centre, Karachi, from January 2013 to September 2014, and comprised chronic kidney disease patients and healthy controls. Serum cholesterol, triglycerides, high-density lipoprotein, C-reactive protein and myeloperoxidase levels were noted. Data was subjected to statistical analysis.. Of the 150 subjects, 84(56%) were cases and 66(44%) were controls. Weight, body mass index, triglycerides, very low-density lipoprotein, C-reactive protein and myeloperoxidase levels were significantly higher among the cases compared to the controls (p<0.05). Serum myeloperoxidase had a significantly positive association with C-reactive protein (p<0.01), cholesterol (p<0.01), triglycerides (p<0.01), low-density lipoprotein (p<0.01) and very low-density lipoprotein (p<0.01), and had a negative correlation with high-density lipoprotein (p<0.01).. Myeloperoxidase concentration had association with lipid profile and C-reactive protein.

Topics: Cardiovascular Diseases; Cholesterol, HDL; Cross-Sectional Studies; Humans; Peroxidase; Renal Insufficiency, Chronic; Tertiary Care Centers; Triglycerides

Neutrophil extracellular traps (NETs) are DNA scaffolds enriched with antimicrobial proteins. NETs have been implicated in the development of various diseases, such as cardiovascular disease. Here, we investigate the association of demographic and cardiovascular (CVD) risk factors with NETs in the general population.. Citrated plasma was collected from 6449 participants, aged ≥55 years, as part of the prospective population-based Rotterdam Study. NETs were quantified by measuring MPO-DNA complex using an ELISA. We used linear regression to determine the associations between MPO-DNA complex and age, sex, cardio-metabolic risk factors, and plasma markers of inflammation and coagulation.. MPO-DNA complex levels were weakly associated with age (log difference per 10 year increase: -0.04 mAU/mL, 95% confidence interval [CI] -0.06;-0.02), a history of coronary heart disease (yes versus no: -0.10 mAU/mL, 95% CI -0.17;-0.03), the use of lipid-lowering drugs (yes versus no: -0.06 mAU/mL, 95% CI -0.12;-0.01), and HDL-cholesterol (per mmol/l increase: -0.07 mAU/mL/, 95% CI -0.12;-0.03).. Older age, a history of coronary heart disease, the use of lipid-lowering drugs and higher HDL-cholesterol are weakly correlated with lower plasma levels of NETs. These findings show that the effect of CVD risk factors on NETs levels in a general population is only small and may not be of clinical relevance. This supports that NETs may play a more important role in an acute phase of disease than in a steady state situation.

Topics: Age Factors; Aged; Cardiovascular Diseases; DNA; Extracellular Traps; Female; Heart Disease Risk Factors; Humans; Male; Middle Aged; Peroxidase; Prospective Studies

Neutrophil extracellular traps (NET) are essential in host defense, but are also linked to inflammation and autoimmunity, including in systemic lupus erythematosus (SLE). We recently described that immune complexes (IC) induce NET formation, promoting SLE-like disease in mice. In the current study, we investigated, for the first time to our knowledge, the role of NET in human SLE and their association with disease activity and severity.. Levels of NET (myeloperoxidase-DNA complexes) were analyzed in plasma from 4 cross-sectional SLE cohorts (n = 44-142), 1 longitudinal SLE cohort (n = 47), and healthy individuals (n = 100) using ELISA. Type I interferon activity was determined using a cell reporter system.. Patients with SLE had elevated levels of NET in circulation compared to healthy controls (p < 0.01). NET levels identified patients with a severe disease phenotype characterized by IC-driven nephritis (p < 0.05). Though not associated with current disease activity (p = 0.20), levels of NET were associated with future increase in the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) within 3 months (OR 1.75, p = 0.01), as well as an overall heightened SLEDAI over 1 year (p < 0.01). Finally, levels of NET were associated with arterial events (OR 5.0, p = 0.02) and endothelial cell activation (p < 0.001).. NET levels are elevated in patients with SLE, associated with IC-driven disease. NET levels provide significant clinical value in identifying patients at risk of active disease and/or severe disease, including nephritis and cardiovascular disease, and may allow for early interventions.

Topics: Animals; Biomarkers; Cardiovascular Diseases; Comorbidity; Cross-Sectional Studies; Extracellular Traps; Humans; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice; Peroxidase

The objective of this study was to evaluate causes of death in a contemporary inception cohort of ANCA-associated vasculitis patients, stratifying the analysis according to ANCA type.. We identified a consecutive inception cohort of patients newly diagnosed with ANCA-associated vasculitis from 2002 to 2017 in the Partners HealthCare System and determined vital status through the National Death Index. We determined cumulative mortality incidence and standardized mortality ratios (SMRs) compared with the general population. We compared MPO- and PR3-ANCA+ cases using Cox regression models.. The cohort included 484 patients with a mean diagnosis age of 58 years; 40% were male, 65% were MPO-ANCA+, and 65% had renal involvement. During 3385 person-years (PY) of follow-up, 130 patients died, yielding a mortality rate of 38.4/1000 PY and a SMR of 2.3 (95% CI: 1.9, 2.8). The most common causes of death were cardiovascular disease (CVD; cumulative incidence 7.1%), malignancy (5.9%) and infection (4.1%). The SMR for infection was greatest for both MPO- and PR3-ANCA+ patients (16.4 and 6.5). MPO-ANCA+ patients had an elevated SMR for CVD (3.0), respiratory disease (2.4) and renal disease (4.5). PR3- and MPO-ANCA+ patients had an elevated SMR for malignancy (3.7 and 2.7). Compared with PR3-ANCA+ patients, MPO-ANCA+ patients had a higher risk of CVD death [hazard ratio 5.0 (95% CI: 1.2, 21.2]; P = 0.03].. Premature ANCA-associated vasculitis mortality is explained by CVD, infection, malignancy, and renal death. CVD is the most common cause of death, but the largest excess mortality risk in PR3- and MPO-ANCA+ patients is associated with infection. MPO-ANCA+ patients are at higher risk of CVD death than PR3-ANCA+ patients.

Topics: Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Cardiovascular Diseases; Cause of Death; Female; Humans; Kidney Diseases; Male; Middle Aged; Mortality, Premature; Neoplasms; Peroxidase; Proportional Hazards Models; Retrospective Studies

Myeloperoxidase (MPO) is known to cause oxidative stress and inflammation leading to cardiovascular disease (CVD) complications. MPO-mediated oxidation of lipoproteins leads to dysfunctional entities altering the landscape of lipoprotein functionality. The specificity of guaiacol derivatives toward preventing MPO-mediated oxidation to limit MPO's harmful effects is unknown. Diligent in silico studies were accomplished for a portfolio of compounds with guaiacol as a building block. The compounds' activity toward MPO inhibition was also validated. The role of these chemical entities in controlling MPO-mediated oxidation of lipoproteins (LDL and HDL) was shown to agree with our approach of developing powerful MPO inhibitors. The mechanism of MPO inhibition was demonstrated to be reversible in nature. This study reveals that there is great potential for guaiacol derivatives as therapeutics for CVD by modulating lipid profiles, reducing atherosclerotic plaque burden, and subsequently optimizing cardiovascular functions.

Topics: Animals; Antioxidants; Atherosclerosis; Benzothiazoles; Biphenyl Compounds; Cardiovascular Diseases; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Enzyme Inhibitors; Guaiacol; Humans; Interleukin-1beta; Lipopolysaccharides; Mice; Molecular Docking Simulation; Molecular Structure; Peroxidase; Picrates; RAW 264.7 Cells; Structure-Activity Relationship; Sulfonic Acids; Tumor Necrosis Factor-alpha

The majority of fatalities thus far in the COVID-19 pandemic have been attributed to pneumonia. As expected, the fatality rate reported in China is higher in people with chronic pulmonary disease (6.3%) and those who have cancer (5.6%). According to the American College of Cardiology Clinical Bulletin "COVID-19 Clinical Guidance for the CV Care Team", there is a significantly higher fatality rate in people who are elderly (8.0% 70-79 years; 14.8% ≥80 years), diabetic (7.3%), hypertensive (6.0%), or have known cardiovascular disease (CVD) (10.5%). We propose a biological reason for the higher mortality risk in these populations that is apparent. We further present a set of pathophysiological reasons for the heightened danger that could lead to therapies for enhanced management and prevention.

Topics: Adult; Aging; Cardiovascular Diseases; Child; COVID-19; Diabetes Mellitus; Disease Susceptibility; Humans; Hydrogen Peroxide; Hypertension; Hypochlorous Acid; Immunity, Innate; Lung; Microcirculation; Microvessels; Neutrophils; Pandemics; Peroxidase; Risk Factors; United States

Volume status is a key parameter for cardiovascular-related mortality in dialysis patients. Although N-terminal pro-B-type natriuretic peptide (NT-proBNP), myeloperoxidase, copeptin, and pro-adrenomedullin have been reported as volume markers, the relationship between body fluid status and volume markers in dialysis patients is uncertain. Therefore, we investigated the utility of volume status biomarkers based on body composition monitor (BCM) analyses.We enrolled pre-dialysis, hemodialysis (HD), and peritoneal dialysis (PD) patients and age- and gender-matched healthy Korean individuals (N = 80). BCM and transthoracic echocardiography were performed and NT-proBNP, myeloperoxidase, copeptin, and pro-adrenomedullin concentrations were measured. Relative hydration status (ΔHS, %) was defined in terms of the hydration status-to-extracellular water ratio with a cutoff of 15%, and hyperhydrated status was defined as ΔHS > 15%.Although there were no significant differences in total body water, extracellular water, or intracellular water among groups, mean amount of volume overload and hyperhydrated status were significantly higher in HD and PD patients compared with control and pre-dialysis patients. Mean amount of volume overload and hyperhydrated status were also significantly associated with higher NT-proBNP and pro-adrenomedullin levels in HD and PD patients, although not with myeloperoxidase or copeptin levels. Furthermore, they were significantly associated with cardiac markers (left ventricular mass index, ejection fraction, and left atrial diameter) in HD and PD patients compared with those in the control and pre-dialysis groups.On the basis of increased plasma NT-proBNP and pro-adrenomedullin concentrations, we might be able to make predictions regarding the volume overload status of dialysis patients, and thereby reduce cardiovascular-related mortality through appropriate early volume control.

Topics: Adrenomedullin; Adult; Biomarkers; Body Composition; Body Fluids; Cardiovascular Diseases; Case-Control Studies; Dialysis; Echocardiography; Female; Glycopeptides; Humans; Male; Middle Aged; Natriuretic Peptide, Brain; Peptide Fragments; Peritoneal Dialysis; Peroxidase; Protein Precursors; Renal Dialysis; Republic of Korea; Stroke Volume; Treatment Outcome; Ventricular Dysfunction, Left

Mean platelet volume (MPV) and platelet count (PLT) are platelet measures that have been linked to cardiovascular disease (CVD) and mortality risk. Identifying protein biomarkers for these measures may yield insights into CVD mechanisms.. We aimed to identify causal protein biomarkers for MPV and PLT among 71 CVD-related plasma proteins measured in FHS (Framingham Heart Study) participants.. We conducted integrative analyses of genetic variants associated with PLT/MPV with protein quantitative trait locus variants associated with plasma proteins followed by Mendelian randomization to infer causal relations of proteins for PLT/MPV. We also tested protein-PLT/MPV association in FHS participants. Using induced pluripotent stem cell-derived megakaryocyte clones that produce functional platelets, we conducted RNA-sequencing and analyzed expression differences between low- and high-platelet producing clones. We then performed small interfering RNA gene knockdown experiments targeting genes encoding proteins with putatively causal platelet effects in megakaryocyte clones to examine effects on platelet production. In protein-trait association analyses, ten proteins were associated with MPV and 31 with PLT. Mendelian randomization identified 4 putatively causal proteins for MPV and 4 for PLT. GP-5 (Glycoprotein V), GRN (granulin), and MCAM (melanoma cell adhesion molecule) were associated with PLT, while MPO (myeloperoxidase) showed significant association with MPV in both analyses. RNA-sequencing analysis results were directionally concordant with observed and Mendelian randomization-inferred associations for GP-5, GRN, and MCAM. In siRNA gene knockdown experiments, silencing GP-5, GRN, and MPO decreased PLTs. Genome-wide association study results suggest several of these may be linked to CVD risk.. We identified 4 proteins that are causally linked to PLTs. These proteins may also have roles in the pathogenesis of CVD via a platelet/blood coagulation-based mechanism.

Topics: Biomarkers; Blood Proteins; Cardiovascular Diseases; CD146 Antigen; Cell Differentiation; Female; Gene Silencing; Genome-Wide Association Study; Granulins; Humans; Longitudinal Studies; Male; Mean Platelet Volume; Megakaryocyte Progenitor Cells; Megakaryocytes; Mendelian Randomization Analysis; Middle Aged; Peroxidase; Phenotype; Platelet Count; Platelet Membrane Glycoproteins; Pluripotent Stem Cells; Risk; RNA, Small Interfering; Sequence Analysis, RNA

Topics: Biomarkers; Cardiovascular Diseases; Diabetes Mellitus; Glycated Hemoglobin; Humans; Inflammation; Lipoproteins, LDL; Peroxidase; Physicians; Prediabetic State; Risk Factors; Risk Reduction Behavior

Cardiovascular disease (CVD) is the leading cause of death in patients with end-stage renal disease (ESRD). Elevated serum concentrations of myeloperoxidase (MPO) are associated with an increased risk of developing CVD. The objective of this study was to evaluate serum MPO levels, as well as other laboratory parameters, in individuals with ESRD, with and without CVD, undergoing hemodialysis.. 80 volunteers were admitted, divided into the following groups: control group (CON): 20 individuals without chronic kidney disease (CKD); ESRD group: 45 individuals with CKD stage V and ESRD/CVD group: 15 individuals with CKD stage V and with CVD. The following biomarkers were evaluated: MPO, High sensitivity C-reactive protein (hs-CRP) and α1-acid glycoprotein, following the manufacturer's guidelines in the package inserts. The data were processed through the statistical software SPSS 20.0. The level of MPO for the CON group was 84 ng/mL (73-87 ng/mL), for the ESRD group 77 ng/mL (11-89 ng/mL) and for the ESRD/CVD group 21 ng/mL (8-47 ng/mL), with a significant statistical difference of the ESRD/CVD group from the CON and ESRD groups (p<0.001). For the parameters hs-CRP and α1-acid glycoprotein a statistical difference between the ESRD and ESRD/CVD groups from the CON group (p<0.0001) was observed, but not between the ESRD and ESRD/CVD groups.. It is suggested that further studies should be performed to define the potential role of MPO as a cardiovascular risk marker for patients with ESRD on hemodialysis.

Topics: Adult; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Female; Heart Disease Risk Factors; Humans; Kidney Failure, Chronic; Male; Middle Aged; Orosomucoid; Peroxidase; Renal Dialysis

Background Mechanisms related to the influence of diet on the development of cardiovascular disease are not entirely understood, and protein biomarkers may help to understand these pathways. Studies of biomarkers identified with multiplex proteomic methods and dietary patterns are largely lacking. Methods and Results Dietary patterns were generated through principal component analysis in 2 population-based Swedish cohorts, the EpiHealth (EpiHealth study; n=20 817 men and women) and the SMCC (Swedish Mammography Cohort Clinical [n=4650 women]). A set of 184 protein cardiovascular disease biomarkers were measured with 2 high-throughput, multiplex immunoassays. Discovery and replication multivariable linear regression analyses were used to investigate the associations between the principal component analysis-generated dietary patterns and the cardiovascular disease-associated protein biomarkers, first in the EpiHealth (n=2240) and then in the Swedish Mammography Cohort Clinical. Four main dietary patterns were identified in the EpiHealth, and 3 patterns were identified in the Swedish Mammography Cohort Clinical. The healthy and the Western/traditional patterns were found in both cohorts. In the EpiHealth, 57 protein biomarkers were associated with 3 of the dietary patterns, and 41 of these associations were replicated in the Swedish Mammography Cohort Clinical, with effect estimates ranging from 0.057 to 0.083 (P-value range, 5.0×10

Topics: Aged; Biomarkers; Blood Proteins; Cardiovascular Diseases; Cross-Sectional Studies; Diet; Diet, Healthy; Feeding Behavior; Female; High-Throughput Screening Assays; Humans; Immunoassay; Male; Middle Aged; Nutritional Status; Nutritive Value; Peroxidase; Proteomics; Resistin; Sweden

Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have an elevated risk of cardiovascular disease (CVD). This study was undertaken to develop a clearer understanding of the association between changes in disease activity and lipid levels in AAV, which may inform CVD risk stratification in this population.. Lipid levels were assessed in stored serum samples (obtained at baseline and month 6) from the Rituximab for ANCA-Associated Vasculitis (RAVE) trial, which randomized patients to receive either rituximab or cyclophosphamide followed by azathioprine. Paired t-tests and multivariable linear regression were used to assess changes in lipid levels.. Of the 142 patients with serum samples available, the mean ± SD age was 52.3 ± 14.7 years, 72 (51%) were male, 95 (67%) were proteinase 3 (PR3)-ANCA positive, 72 (51%) had received a new diagnosis of AAV, and 75 (53%) were treated with rituximab. Several lipid levels increased between baseline and month 6, including total cholesterol (+12.4 mg/dl [95% confidence interval (95% CI) +7.1, +21.0]), low-density lipoprotein (+10.3 mg/dl [95% CI +6.1, +17.1]), and apolipoprotein B (+3.5 mg/dl [95% CI +1.0, +8.3]). These changes were observed among newly diagnosed and PR3-ANCA-positive patients but not among those with relapsing disease or myeloperoxidase-ANCA-positive patients. There was no difference in change in lipid levels between rituximab-treated patients and cyclophosphamide-treated patients. Changes in lipid levels correlated with changes in erythrocyte sedimentation rate but not with other inflammatory markers or glucocorticoid exposure.. Lipid levels increased during remission induction among patients with newly diagnosed AAV and those who were PR3-ANCA positive. Disease activity and ANCA type should be considered when assessing lipid profiles to stratify CVD risk in patients with AAV.

Topics: Adult; Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Antirheumatic Agents; Apolipoprotein A-I; Apolipoproteins B; Azathioprine; Blood Sedimentation; Cardiovascular Diseases; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cyclophosphamide; Female; Humans; Lipid Metabolism; Male; Middle Aged; Myeloblastin; Peroxidase; Randomized Controlled Trials as Topic; Rituximab; Severity of Illness Index

The early onset of cardio-metabolic abnormalities, known as metabolically unhealthy (MU) status, is highly associated with obesity and cardiovascular disease (CVD), as well as with increased morbidity and mortality later in life. Given the lack of a consensus MU classification for prepubertal children, we aimed to compare available MU definitions in terms of their association with CVD risk biomarkers.. A total of 930 prepubertal children (622 with overweight/obesity, 462 males) aged 5-10.9 years were recruited, anthropometric measures were taken and biomarkers were analyzed. Children were classified using eight MU definitions based on different cut-offs for blood pressure, triacylglycerides, high-density lipoprotein cholesterol, glucose and homeostasis model assessment for insulin resistance (HOMA-IR). MU prevalence in children with overweight/obesity ranged between 30% and 60% across definitions. Plasma concentrations of resistin, leptin, myeloperoxidase (MPO) and total plasminogen activator inhibitor 1 (tPAI-1) were higher, and those of adiponectin were lower, in MU compared to MH children with overweight/obesity. Linear regression analyses confirmed the contribution of MPO and tPAI-1 concentrations to MU status, with most significant results derived from definitions that use age and sex-specific criteria and that account for HOMA-IR.. Plasma concentrations of MPO and tPAI-1 are increased in prepubertal MU children irrespective of having normal-weight or overweight/obesity. Inclusion of age and sex-specific cut-offs for cardio-metabolic components as well as insulin resistance criteria increases the quality of MU definitions as seen by their stronger association with CVD biomarkers concentrations.

Topics: Age Factors; Biomarkers; Cardiovascular Diseases; Child; Child, Preschool; Female; Health Status; Humans; Insulin Resistance; Male; Metabolic Syndrome; Pediatric Obesity; Peroxidase; Plasminogen Activator Inhibitor 1; Predictive Value of Tests; Prevalence; Risk Factors; Sex Factors; Spain; Terminology as Topic

Oxidative stress has been proposed as important pathomechanism of cardiometabolic diseases and distal sensorimotor polyneuropathy (DSPN). However, the relevance of biomarkers of oxidative stress has not been investigated in this context. Therefore, this study aimed to assess the association of the prooxidant myeloperoxidase (MPO) and the antioxidant extracellular superoxide dismutase (SOD3) with cardiometabolic risk factors and with prevalence and incidence of DSPN.. Cross-sectional analyses comprised 1069 participants (40.3% with prediabetes and 20.5% with type 2 diabetes) of the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study (2006-2008), 181 of whom had DSPN at baseline. Prospective analyses included 524 individuals without DSPN at baseline who also participated in the KORA FF4 study (2013-2014), 132 of whom developed DSPN during the 6.5-year follow-up. Serum MPO and SOD3 were measured by ELISA, and their association with cardiometabolic risk factors and DSPN were estimated by using linear and logistic regression analyses.. Higher MPO and SOD levels showed multiple positive associations with cardiometabolic risk factors including age, indices of obesity, insulin resistance, serum lipids, renal dysfunction, and biomarkers of inflammation. Higher MPO levels were associated with prevalent DSPN (fully adjusted OR 1.38 [95% CI 1.10; 1.72] per doubling of MPO). Higher baseline SOD3 levels were related to incident DSPN (age and sex-adjusted OR 2.14 [1.02; 4.48] per doubling of SOD3), which was partially explained by cardiometabolic risk factors.. Systemic levels of both pro- and antioxidant enzymes appear involved in cardiometabolic risk and development of DSPN.

Topics: Aged; Aged, 80 and over; Biomarkers; Cardiovascular Diseases; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Humans; Male; Metabolic Diseases; Middle Aged; Peroxidase; Polyneuropathies; Prediabetic State; Prognosis; Prospective Studies; Risk Factors; Sensorimotor Cortex; Superoxide Dismutase

Myeloperoxidase (MPO)-derived oxidants have emerged as a key contributor to tissue damage in inflammatory conditions such as cardiovascular disease. Pro-myeloperoxidase (pro-MPO), an enzymatically active precursor of myeloperoxidase (MPO), is known to be secreted from cultured bone marrow and promyelocytic leukemia cells, but evidence for the presence of pro-MPO in circulation is lacking. In the present study, we used a LC-MS/MS in addition to immunoblot analyses to show that pro-MPO is present in human blood plasma. Furthermore, we found that pro-MPO was more frequently detected in plasma from patients with myocardial infarction compared to plasma from control donors. Our study suggests that in addition to mature MPO, circulating pro-MPO may cause oxidative modifications of proteins thereby contributing to cardiovascular disease.

Topics: Amino Acid Sequence; Animals; Cardiovascular Diseases; CHO Cells; Cricetinae; Cricetulus; Enzyme Precursors; Halogenation; HL-60 Cells; Humans; Immunoblotting; Myocardial Infarction; Oxidation-Reduction; Peroxidase; Rabbits

Cardiovascular morbidity and mortality of premenopausal women are significantly lower compared to men of similar age. However, this protective effect evidently decreases after the onset of menopause. We hypothesized that physical exercise could be a potential therapeutic strategy to improve inflammatory processes and cardiovascular antioxidant homeostasis, which can be affected by the loss of estrogen and the adverse environmental factors, such as overnutrition. Ovariectomized (OVX, n= 40) and sham-operated (SO, n= 40) female Wistar rats were randomized to exercising (R) and non-exercising (NR) groups. Feeding parameters were chosen to make a standard chow (CTRL) or a high triglyceride diet (HT) for 12 weeks. Aortic and cardiac heme oxygenase (HO) activity and HO-1 concentrations significantly decreased in all of the NR OVX and SO HT groups. However, the 12-week physical exercise was found to improve HO-1 values. Plasma IL-6 concentrations were higher in the NR OVX animals and rats fed HT diet compared to SO CTRL rats. TNF-α concentrations were significantly higher in the NR OVX groups. 12 weeks of exercise significantly reduced the concentrations of both TNF-α and IL-6 compared to the NR counterparts. The activity of myeloperoxidase enzyme (MPO) was significantly increased as a result of OVX and HT diet, however voluntary wheel-running exercise restored the elevated values. Our results show that estrogen deficiency and HT diet caused a significant decrease in the activity and concentration of HO enzyme, as well as the concentrations of TNF-α, IL-6, and the activity of MPO. However, 12 weeks of voluntary wheel-running exercise is a potential non-pharmacological therapy to ameliorate these disturbances, which determine the life expectancy of postmenopausal women.

Topics: Animals; Aorta; Body Weight; Cardiovascular Diseases; Diet, High-Fat; Estrogens; Female; Heme Oxygenase (Decyclizing); Inflammation; Interleukin-6; Myocardium; Ovariectomy; Peroxidase; Physical Conditioning, Animal; Random Allocation; Rats, Wistar; Risk Factors; Triglycerides; Tumor Necrosis Factor-alpha

Cardiovascular disease is a major contributing factor to long-term mortality after liver transplantation (LT).. This study evaluated the evolution of atherogenic risk in liver transplant recipients (LTRs). Thirty-six subjects were prospectively enrolled at 12 months and followed for 48 months after liver transplantation. Serum biomarkers of endothelial dysfunction (sICAM-1 and sVCAM-1), chronic inflammation (serum amyloid A), and oxidative stress (myeloperoxidase) were measured at 12 and 48 months after LT. Additionally, at 12 months all patients underwent a cardiac computed tomography (CT) scan and a coronary artery calcium score (CACS).. The prevalence of risk factors of metabolic syndrome (MS) increased over the course of the study. The patients' sVCAM-1 and sICAM-1 increased from 1.82 ± 0.44 ng/mL to 9.10 ± 5.82 ng/mL (P < .001) and 0.23 ± 0.09 ng/mL to 2.7 ± 3.3 ng/mL, respectively from month 12 to 48. Serum myeloperoxidase increased from 0.09 ± 0.07 ng/mL to 3.46 ± 3.92 ng/mL (P < .001) over the course of the study. Serum amyloid A also increased from 21.4 ± 40.7 ng/mL at entry to 91.5 ± 143.6 ng/mL at end of study (P < .001).. No association between these biomarkers and MS was noted. The cardiac CT revealed mild and moderate disease in 19% and 25% of the cohort, respectively. No association between serum biomarkers and CACS was noted. Serum biomarkers of atherogenic risk increase rapidly in LTRs and precede coronary plaques.

Topics: Adult; Atherosclerosis; Biomarkers; Calcium; Cardiovascular Diseases; Female; Follow-Up Studies; Humans; Intercellular Adhesion Molecule-1; Liver Transplantation; Male; Metabolic Syndrome; Middle Aged; Peroxidase; Postoperative Complications; Postoperative Period; Prevalence; Prospective Studies; Risk Factors; Serum Amyloid A Protein; Vascular Cell Adhesion Molecule-1

The leukocyte-derived myeloperoxidase (MPO), the nitric oxidase synthase (NOS) inhibitor asymmetrical dimethyl-arginine (ADMA) and the renin-angiotensin-aldosterone-system (RAAS) are associated with cardiovascular diseases (CVD). This study aimed to investigate potential interactions between the RAAS, ADMA and MPO in cardiovascular risk patients.. All in all, 1446 patients, who were referred to coronary angiography, were included in this prospective study. MPO, ADMA and circulating serum markers of the RAAS system were measured. Additionally, all-cause and CVD mortality, cardiovascular risk factors, inflammatory and endothelial markers, and medication use were investigated.. MPO concentrations were significantly associated with ADMA (P=0.002), renin (P=0.001) and angiotensin II levels (P=0.015), whereas ADMA was in tendency associated with renin (P=0.059) and significantly with angiotensin II (P=0.001). Both, ADMA and MPO were inversely correlated with angiotensinogen, angiotensin I and the angiotensin I/angiotensin II ratio. ADMA and angiotensin II were found stronger independent risk factors for all-cause and CVD mortality compared to MPO.. MPO concentrations were significantly associated with higher ADMA levels and an up-regulated circulating RAAS in patients with CVD. Moreover, serum levels of ADMA and angiotensin II were shown to be more predictive for all-cause and CVD mortality compared to MPO.

Topics: Aged; Aldosterone; Arginine; Austria; Biomarkers; Cardiovascular Diseases; Cohort Studies; Coronary Angiography; Cross-Sectional Studies; Female; Follow-Up Studies; Germany; Glutathione Peroxidase; Glutathione Peroxidase GPX1; Humans; Male; Middle Aged; Mortality; Peroxidase; Predictive Value of Tests; Prevalence; Prospective Studies; Renin-Angiotensin System; Risk Factors

Myeloperoxidase (MPO), a product of systemic inflammation, promotes oxidation of lipoproteins; whereas, high-density lipoprotein (HDL) exerts anti-oxidative effects in part via paraoxonase-1 (PON1). MPO induces dysfunctional HDL particles; however, the interaction of circulating levels of these measures in cardiovascular disease (CVD) has not been studied in humans. We tested whether serum levels of MPO indexed to HDL particle concentration (MPO/HDLp) are associated with increased CVD risk in a large multiethnic population sample, free of CVD at baseline.. Levels of MPO, HDL-C, and HDL particle concentration (HDLp) by NMR were measured at baseline in 2924 adults free of CVD. The associations of MPO/HDLp with incident ASCVD (first non-fatal myocardial infarction, non-fatal stroke, coronary revascularization, or CVD death) and total CVD were assessed in Cox proportional-hazards models adjusted for traditional risk factors. The median follow-up period was 9.4 years.. Adjusted for sex and race/ethnicity, MPO/HDLp was associated directly with body mass index, smoking status, high-sensitivity C-reactive protein, and interleukin 18, and inversely with age, HDL-C levels, HDL size, and PON1 arylesterase activity, but not with cholesterol efflux. In fully adjusted models, the highest versus lowest quartile of MPO/HDLp was associated with a 74% increase in incident ASCVD (aHR, 1.74, 95% CI 1.12-2.70) and a 91% increase in total incident CVD (aHR, 1.91, 95% CI 1.27-2.85).. Increased MPO indexed to HDL particle concentration (MPO/HDLp) at baseline is associated with increased risk of incident CVD events in a population initially free of CVD over the 9.4 year period.

Topics: Adult; Aged; Biomarkers; Cardiovascular Diseases; Comorbidity; Female; Humans; Incidence; Kaplan-Meier Estimate; Life Style; Lipoproteins, HDL; Male; Middle Aged; Multivariate Analysis; Nuclear Magnetic Resonance, Biomolecular; Peroxidase; Proportional Hazards Models; Risk Factors; Texas; Time Factors

Myeloperoxidase (MPO), an enzyme linking obesity and cardiovascular (CV) risk in adults, has rarely been studied in young children and no studies assessed its association with renal function. We sought to explore a possible association between serum MPO levels, obesity, CV risk factors and renal function in prepubertal children.. Cross-sectional evaluation of 309 children aged 8-9 years (161 normal weight, 148 overweight/obese), members of the birth cohort Generation I (Portugal). Anthropometrics (body mass index (BMI), waist-to-height ratio (WHtR) and % body fat mass (%BFM) by bioelectrical impedance analysis), 24-h ambulatory blood pressure monitoring and pulse wave velocity (PWV) were measured. Insulin resistance was estimated by the HOMA index (considering serum fasting glucose and insulin determinations). Serum MPO levels were assessed by immunoenzymatic assay.. MPO levels were positively associated with obesity indices (BMI z-score, WHtR and %BFM). Higher MPO levels were associated with higher 24-h and night-time mean arterial pressure, with nondipping and with higher values of insulin resistance. In normal weight children, the endothelial function, as evaluated indirectly by PWV, was an independent predictor of MPO levels. In overweight/obese children, estimated glomerular filtration rate increased significantly across tertiles of MPO (Ptrend = 0·031) and this association held after adjustment for age, sex, neutrophil and monocyte counts and CV risk factors.. Our results reinforce the role of MPO as a risk marker in obesity and related CV morbidities in young children. MPO levels associate with the dipping pattern and PWV and, among overweight/obese children, an association exists between MPO and renal function.

Topics: Adipose Tissue; Blood Glucose; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Body Composition; Cardiovascular Diseases; Child; Cohort Studies; Cross-Sectional Studies; Electric Impedance; Endothelium, Vascular; Female; Glomerular Filtration Rate; Humans; Insulin; Insulin Resistance; Male; Obesity; Overweight; Peroxidase; Portugal; Pulse Wave Analysis; Risk Factors

Chronic low-grade inflammation, combined with traditional cardiovascular risk factors, is common in obesity, providing systemic inflammation that is associated with increased cardiovascular risk. Studies have shown serum mieloperoxidase as a potential biomarker and its clinical applicability for evaluating cardiovascular risk. This study aimed to evaluate the MPO in obese individuals, with or without systemic inflammation and potential cardiovascular risk, as well as correlating MPO with some classic cardiovascular risk parameters.. Inflammatory and cardiovascular risk markers, as well as different biochemical and hematological laboratory parameters, were analyzed. The volunteers were divided into 3 groups according to the presence (hs-CRP>3 mg/L) or absence (hs-CRP<3 mg/L) of systemic inflammation and possible cardiovascular risk.. MPO was significantly increased (p<0.05) in the obese individuals with systemic inflammation. A significant increase (p<0.05) in the following biochemical parameters: glucose, HbA1c, triglycerides, non-HDL, TG/HDL was observed, and a significant decrease (p<0.01) in HDL was observed. Significant increases in the counts of total leukocytes, neutrophils and monocytes (p<0.01), as well as elevated blood pressure (p<0.05), were observed in the group of obese individuals with systemic inflammation. Serum MPO levels were correlated with classic proinflammatory and cardiovascular risk parameters.. High serum levels of MPO were observed in obese individuals with hs-CRP above 3 mg/L, which is a classic biomarker for inflammation and cardiovascular risk, suggesting the potential role of MPO in clinical applicability for cardiovascular disease in this population. However, considering that inflammation in obesity appears to manifest as a non-classical mechanism, further studies are necessary to elucidate the role of MPO in cardiovascular events in the population with obesity.

Topics: Adult; Biomarkers; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Female; Glycated Hemoglobin; Humans; Lipids; Male; Middle Aged; Obesity; Peroxidase; Risk Factors

Several biomarkers have individually been shown to be useful for risk stratification in patients with acute myocardial infarction (MI). The optimal multimarker strategy remains undefined.. Biomarkers representing different pathobiological axes were studied, including myocardial stress/structural changes (NT-pro B-type natriuretic peptide [NT-proBNP], midregional proatrial natriuretic peptide [MR-proANP], suppression of tumorigenicity 2 [ST2], galectin-3, midregional proadrenomedullin [MR-proADM], and copeptin), myonecrosis (troponin T), and inflammation (myeloperoxidase [MPO], high sensitivity C-reactive protein [hsCRP], pregnancy-associated plasma protein A [PAPP-A], and growth-differentiation factor-15 [GDF-15]), in up to 1258 patients from Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis in Myocardial Infarction 28 (CLARITY-TIMI 28), a randomized trial of clopidogrel in ST-elevation MI (STEMI). Patients were followed for 30 days. Biomarker analyses were adjusted for traditional clinical variables. Forward step-wise selection was used to assess a multimarker strategy. After adjustment for clinical variables and using a dichotomous cutpoint, 7 biomarkers were each significantly associated with a higher odds of cardiovascular death or heart failure (HF) through 30 days, including NT-proBNP (adjusted odds ratio [ORadj], 2.54; 95% CI, 1.47-4.37), MR-proANP (2.18; 1.27-3.76), ST2 (2.88; 1.72-4.81), troponin T (4.13; 1.85-9.20), MPO (2.75; 1.20-6.27), hsCRP (1.96, 1.17-3.30), and PAPP-A (3.04; 1.17-7.88). In a multimarker model, 3 biomarkers emerged as significant and complementary predictors of cardiovascular death or HF: ST2 (ORadj, 2.87; 1.61-5.12), troponin T (2.34; 1.09-5.01 and 4.13, 1.85-9.20, respectively for intermediate and high levels), and MPO (2.49; 1.04-5.96). When added to the TIMI STEMI Risk Score alone, the multimarker risk score significantly improved the C-statistic (area under the curve, 0.75 [95% CI, 0.69-0.81] to 0.82 [0.78-0.87]; P=0.001), net reclassification index (0.93; P<0.001), and integrated discrimination index (0.09; P<0.001).. In patients with STEMI, a multimarker strategy that combines biomarkers across pathobiological axes of myocardial stress, myocyte necrosis, and inflammation provides incremental prognostic information for prediction of cardiovascular death or HF.

Topics: Adrenomedullin; Aged; Atrial Natriuretic Factor; Biomarkers; Blood Proteins; C-Reactive Protein; Cardiovascular Diseases; Female; Galectin 3; Galectins; Glycopeptides; Growth Differentiation Factor 15; Heart Failure; Humans; Interleukin-1 Receptor-Like 1 Protein; Male; Middle Aged; Natriuretic Peptide, Brain; Odds Ratio; Peptide Fragments; Peroxidase; Pregnancy-Associated Plasma Protein-A; Prognosis; Protein Precursors; Risk Assessment; ST Elevation Myocardial Infarction; Troponin T

Whether biomarkers associated with cardiovascular disease risk also predict incident diabetes mellitus (DM) is unknown. Our objective was to determine if a panel of 18 biomarkers previously associated with risk of cardiovascular disease also predicts incident DM in statin-treated patients with coronary artery disease (CAD). The Treating to New Targets (TNT) study is a randomized trial that compared the efficacy of high (80 mg) versus low (10 mg) dose atorvastatin for the secondary prevention of coronary heart disease events. Fasting plasma levels of standard lipids and of 18 emerging CAD risk biomarkers were obtained after an 8-week run-in period on atorvastatin 10 mg in a random sample of 1,424 TNT patients. After exclusion of patients with DM at baseline (n = 253), 101 patients developed DM during the median follow-up of 4.9 years. Patients with incident DM had lower levels of total and high-molecular weight adiponectin, lipoprotein-associated phospholipase A2 (Lp-PLA2), soluble receptor of advanced glycation end products, and vitamin D compared with patients without incident DM. In contrast, insulin, soluble CD40 ligand, and soluble intercellular adhesion molecule-1 levels were higher in patients with incident DM compared with those without. Plasma levels of C-reactive protein, cystatin C, lipoprotein(a), monocyte chemotactic protein-1, matrix metalloproteinase-9, myeloperoxidase, neopterin, N-terminal fragment of pro-B-type natriuretic peptide, osteopontin, and soluble vascular cell adhesion molecule-1 were comparable in patients with and without incident DM. After multivariate adjustment, total and high-molecular weight adiponectin as well as Lp-PLA2 were negatively associated with incident DM. Results of this study suggest that plasma lipids and some emerging CAD risk biomarkers, such as adiponectin and Lp-PLA2, may be useful for predicting incident DM in statin-treated patients with stable CAD.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Adiponectin; Aged; Atorvastatin; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; CD40 Ligand; Chemokine CCL2; Coronary Artery Disease; Cystatin C; Diabetes Mellitus, Type 2; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Incidence; Insulin; Intercellular Adhesion Molecule-1; Lipoprotein(a); Male; Matrix Metalloproteinase 9; Middle Aged; Multivariate Analysis; Natriuretic Peptide, Brain; Neopterin; Osteopontin; Peptide Fragments; Peroxidase; Randomized Controlled Trials as Topic; Receptor for Advanced Glycation End Products; Risk Factors; Secondary Prevention; Vascular Cell Adhesion Molecule-1; Vitamin D

Obstructive sleep apnea (OSA) is characterized by recurrent respiratory disorders associated with increased cardiovascular morbidity and mortality. The increment of systemic inflammation in OSA has been considered as the major pathogenic mechanism leading to cardiovascular diseases. There is limited and conflicting information in the literature investigating myeloperoxidase (MPO) activity and soluble tumor necrosis factor receptor-1 (sTNF-R1) levels in OSA patients. The aim of our study is to assess the clinical utility of plasma MPO activity and sTNF-R1 levels as risk markers for systemic inflammation and development of cardiovascular diseases in OSA patients.. 59 OSA patients diagnosed with polysomnograhpy for Apnea-Hypopnea index (AHI), and 26 healthy volunteers enrolled into the study. Plasma MPO activity was measured using a spectrophotometric method. An enzyme-linked immunosorbent assay (ELISA) method was used to detect plasma sTNF-R1 levels.. Plasma MPO activity and sTNF-R1 levels were significantly higher (43.2 ± 21.65 vs. 30.44 ± 8.05 p = .0046; 2.379 ± 1.2 vs. 1.086 ± 0.86 p < .0001, respectively) in the total OSA patients compared to the control group. There was a significant weak correlation between MPO activity and disease severity indicator AHI (p = .03 r = .27).. Elevated plasma MPO activity and sTNF-R1 levels in the OSA patients indicate increased systemic inflammation and oxidative stress which might contribute to the higher incidence of cardiovascular diseases. Therefore, we recommend measurement of plasma MPO activity and sTNF-R1 levels in the OSA patients as potential risk predictors for cardiovascular diseases.

Topics: Adult; Aged; Biomarkers; Cardiovascular Diseases; Female; Humans; Inflammation; Male; Middle Aged; Oxidative Stress; Peroxidase; Receptors, Tumor Necrosis Factor, Type I; Severity of Illness Index; Sleep Apnea, Obstructive

Evidence associates polyphenol-rich foods to reduction of low-grade inflammation and mortality for cardiovascular disease, the mechanisms underlying such effects being still unclear. Consumption of a fatty meal by healthy volunteers induces rapid and reversible low-grade inflammation. The aim of the present study was to evaluate the effect of orange juice on cellular modifications induced by a fatty meal.. 18 apparently healthy subjects consumed a fatty meal, during which they drunk orange juice, either blond or red, or water, according to a randomized cross-over design. Two hours after the end of the fatty meal, both white blood cell (WBC) and platelet counts significantly increased (12.5 and 5%, respectively), while mean platelet volume decreased and a 25% release of myeloperoxidase (MPO) from polymorphonuclear leukocyte occurred. Both juices significantly prevented WBC increase and MPO degranulation, in respect to control. Triglycerides significantly increased (42%) after the fatty meal, but at a lower extent when red orange juice was consumed with the meal (20%), in respect to blond orange juice or control. This effect was statistically significant in the subgroup of 8 subjects with hypertriglyceridemia. Vascular stiffness (augmentation index), measured by Endo-PAT2000, significantly decreased after the meal only in conjunction with red orange juice.. In healthy subjects the concomitant intake of orange juice may prevent the low-grade inflammatory reaction induced by a fatty meal, at cellular and possibly at vascular function levels. The relative role of different polyphenols on the observed effects of orange juices remains to be established.

Topics: Adult; Beverages; Cardiovascular Diseases; Citrus sinensis; Female; Healthy Volunteers; Humans; Inflammation; Male; Meals; Peroxidase; Postprandial Period; Risk Factors; Triglycerides

To develop an economic model to estimate the change in the number of events and costs of non-fatal myocardial infarction (MI) and non-fatal ischemic stroke (IS) as a result of implementing routine risk-stratification with a multiple inflammatory biomarker approach.. Reductions in the numbers of non-fatal MI and non-fatal IS events and in related per-member-per-month (PMPM) and 5-year costs (excluding test costs) due to biomarker testing were modeled for a US health plan with one million beneficiaries. Inputs for the model included literature-based MI and IS incidence rates, healthcare costs associated with MI and IS, laboratory results of biomarker testing, MI and IS hazard ratios related to biomarker levels, patient monitoring and intervention costs and use/costs of preventative pharmacotherapy. Preventative pharmacotherapy inputs were based on an analysis of pharmacy claims data. Costs savings (2013 USD) were assessed for patients undergoing biomarker testing compared to the standard of care. Data from MDVIP and Cleveland Heart Lab supported two critical inputs: (1) treatment success rates and (2) the population distribution of biomarker testing. Incidence rates, hazard ratios, and other healthcare costs were obtained from the literature.. For a health plan with one million members, an estimated 21,104 MI and 22,589 IS events occurred in a 5-year period. Routine biomarker testing among a sub-group of beneficiaries ≥35 years old reduced non-fatal MI and IS events by 2039 and 1869, respectively, yielding cost savings of over $187 million over 5 years ($3.13 PMPM), excluding test costs. Results were sensitive to changes in treatment response rates. Nonetheless, cost savings were observed for all input values.. This study suggests that health plans can realize substantial cost savings by preventing non-fatal MI and IS events after implementation of routine biomarker testing. Five-year cost savings before test costs could exceed $3.13 PMPM.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Adult; Age Factors; Aged; Aged, 80 and over; Biomarkers; C-Reactive Protein; Cardiovascular Agents; Cardiovascular Diseases; Costs and Cost Analysis; Female; Hematologic Tests; Humans; Insurance Claim Review; Male; Middle Aged; Models, Econometric; Myocardial Infarction; Peroxidase; Risk Assessment; Risk Factors; Stroke; United States

Obesity and type 2 diabetes mellitus (T2DM) are associated with oxidative stress. Oxidative damage of high-density lipoprotein (oxHDL) leads to a dysfunctional molecule, potentially a mediator and/or marker of cardiometabolic disease. We tested the hypothesis that circulating concentration of oxHDL is higher in obese (Ob) or T2DM adolescents compared to normal-weight (NW) peers.. In 37 NW, 38 Ob, and 42 T2DM adolescents, ages 11-18 y, fasting concentrations of HDL and LDL cholesterol, oxHDL, oxidized low-density lipoprotein (oxLDL), and myeloperoxidase (MPO) were measured.. Compared to the NW group, oxHDL in the Ob group was not different, but was 65% higher (p < 0.01) in the T2DM group. Within the T2DM group oxHDL was higher in boys than in girls, but this sex difference was not evident in NW or Ob groups. OxLDL was 23% higher in Ob (p = 0.02), and 56% higher in T2DM (p < 0.01) versus NW and did not differ between boys and girls. MPO was not different between NW and Ob but was 88% (p < 0.02) higher in T2DM compared to NW. Contrary to our hypothesis MPO and insulin resistance (HOMA-IR) were not correlated with oxHDL. OxHDL was positively associated with oxLDL and lean body mass while oxLDL was positively associated with apolipoprotein B, triglycerides, HOMA-IR and trunk fat.. The higher concentrations of oxHDL and oxLDL, along with higher MPO in children with T2DM reflect higher oxidative stress compared with obesity alone and potentially increased cardiovascular disease risk in youth with T2DM.

Topics: Adolescent; Biomarkers; Body Mass Index; Cardiovascular Diseases; Child; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Cardiomyopathies; Female; Humans; Insulin Resistance; Lipoproteins, HDL; Lipoproteins, LDL; Male; Oklahoma; Oxidation-Reduction; Oxidative Stress; Pediatric Obesity; Peroxidase; Risk Factors

Myeloperoxidase (MPO) is a heme peroxidase that catalyzes the production of hypochlorous acid. Clinical evidence suggests a causal role for MPO in various autoimmune and inflammatory disorders including vasculitis and cardiovascular and Parkinson's diseases, implying that MPO inhibitors may represent a therapeutic treatment option. Herein, we present the design, synthesis, and preclinical evaluation of N1-substituted-6-arylthiouracils as potent and selective inhibitors of MPO. Inhibition proceeded in a time-dependent manner by a covalent, irreversible mechanism, which was dependent upon MPO catalysis, consistent with mechanism-based inactivation. N1-Substituted-6-arylthiouracils exhibited low partition ratios and high selectivity for MPO over thyroid peroxidase and cytochrome P450 isoforms. N1-Substituted-6-arylthiouracils also demonstrated inhibition of MPO activity in lipopolysaccharide-stimulated human whole blood. Robust inhibition of plasma MPO activity was demonstrated with the lead compound 2-(6-(5-chloro-2-methoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide (PF-06282999, 8) upon oral administration to lipopolysaccharide-treated cynomolgus monkeys. On the basis of its pharmacological and pharmacokinetic profile, PF-06282999 has been advanced to first-in-human pharmacokinetic and safety studies.

Topics: Acetamides; Animals; Cardiovascular Diseases; Drug Discovery; Enzyme Inhibitors; Humans; Peroxidase; Pyrimidinones; Rats, Wistar

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cardiovascular Diseases; Female; Humans; Peroxidase; Troponin I

The aim of this study was to determine if individual or multiple biomarkers are associated with cardiotoxicity in patients with breast cancer undergoing cancer therapy.. Current methods to identify patients at risk for cardiotoxicity from cancer therapy are inadequate.. We measured 8 biomarkers in a multicenter cohort of 78 patients with breast cancer undergoing doxorubicin and trastuzumab therapy: ultrasensitive troponin I (TnI), high-sensitivity C-reactive protein (CRP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor (GDF)-15, myeloperoxidase (MPO), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor (sFlt)-1, and galectin (gal)-3. Cardiotoxicity, defined by the Cardiac Review and Evaluation Committee criteria, was assessed every 3 months for up to 15 months. Hazard ratios (HRs) of cardiotoxicity risk were assessed for each biomarker at baseline, at visit 2 (3 months), and as a function of the difference between visit 2 and baseline. Joint models were assessed for the most promising biomarkers.. TnI, CRP, GDF-15, MPO, PlGF, and sFlt-1 levels increased from baseline to visit 2 (p < 0.05). A greater risk of cardiotoxicity was associated with interval changes in TnI (HR: 1.38 per SD; 95% confidence interval: 1.05 to 1.81; p = 0.02) and MPO (HR: 1.34 per SD; 95% confidence interval: 1.00 to 1.80; p = 0.048) and in models combining both markers (p = 0.007 and p = 0.03, respectively). The risk of cardiotoxicity was 46.5% in patients with the largest changes in both markers (ΔTnI >121.8 μg/l; ΔMPO >422.6 pmol/l).. Early increases in TnI and MPO levels offer additive information about the risk of cardiotoxicity in patients undergoing doxorubicin and trastuzumab therapy. Independent validation of these findings is necessary before application to clinical practice.

Topics: Adult; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Breast Neoplasms; Cardiovascular Diseases; Cohort Studies; Doxorubicin; Female; Humans; Middle Aged; Peroxidase; Predictive Value of Tests; Taxoids; Time Factors; Trastuzumab; Treatment Outcome; Troponin I

Recent studies have indicated that high-density lipoproteins (HDLs) and their major structural protein, apolipoprotein A1 (apoA1), recovered from human atheroma are dysfunctional and are extensively oxidized by myeloperoxidase (MPO). In vitro oxidation of either apoA1 or HDL particles by MPO impairs their cholesterol acceptor function. Here, using phage display affinity maturation, we developed a high-affinity monoclonal antibody that specifically recognizes both apoA1 and HDL that have been modified by the MPO-H2O2-Cl(-) system. An oxindolyl alanine (2-OH-Trp) moiety at Trp72 of apoA1 is the immunogenic epitope. Mutagenesis studies confirmed a critical role for apoA1 Trp72 in MPO-mediated inhibition of the ATP-binding cassette transporter A1 (ABCA1)-dependent cholesterol acceptor activity of apoA1 in vitro and in vivo. ApoA1 containing a 2-OH-Trp72 group (oxTrp72-apoA1) is in low abundance within the circulation but accounts for 20% of the apoA1 in atherosclerosis-laden arteries. OxTrp72-apoA1 recovered from human atheroma or plasma is lipid poor, virtually devoid of cholesterol acceptor activity and demonstrated both a potent proinflammatory activity on endothelial cells and an impaired HDL biogenesis activity in vivo. Elevated oxTrp72-apoA1 levels in subjects presenting to a cardiology clinic (n = 627) were associated with increased cardiovascular disease risk. Circulating oxTrp72-apoA1 levels may serve as a way to monitor a proatherogenic process in the artery wall.

Topics: Alanine; Antibodies, Monoclonal; Apolipoprotein A-I; Cardiovascular Diseases; Cell Surface Display Techniques; Chromatography, Liquid; Enzyme-Linked Immunosorbent Assay; Epitopes; Fluorescent Antibody Technique; Humans; Immunohistochemistry; Lipoproteins, HDL; Mutagenesis; Odds Ratio; Oxidation-Reduction; Oxindoles; Peroxidase; Plaque, Atherosclerotic; Tandem Mass Spectrometry; Vascular Cell Adhesion Molecule-1

Psoriasis is associated with a systemic inflammation and an increased frequency of the metabolic syndrome, both of which are believed to link psoriasis to an increased risk of cardiovascular disease.. The study aimed to investigate the systemic expression of markers of cardiovascular risk and determine their response to ultraviolet B therapy and treatment with the tumor necrosis factor-alfa inhibitor, etanercept.. Six markers of cardiovascular risk were measured in 28 patients with psoriasis and 28 control subjects.. Five of the 6 investigated markers were elevated in patients with psoriasis. Four of these correlated to the body mass index and waist-hip ratio, suggesting a link to the metabolic syndrome. Total plasminogen activator inhibitor-1 remained elevated independently of these factors. The levels of the investigated risk markers decreased considerably after tumor necrosis factor-alfa inhibitor treatment but remained unaffected by ultraviolet therapy.. A relatively limited study population and nonrandomization are limitations.. These findings suggest that the choice of treatment in psoriasis may influence the cardiovascular risk in patients with psoriasis and the metabolic syndrome.

Topics: Adult; Body Mass Index; Cardiovascular Diseases; Case-Control Studies; Combined Modality Therapy; E-Selectin; Etanercept; Female; Follow-Up Studies; Humans; Immunoglobulin G; Inflammation Mediators; Intercellular Adhesion Molecule-1; Male; Matrix Metalloproteinases; Middle Aged; Peroxidase; Psoriasis; Receptors, Tumor Necrosis Factor; Reference Values; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Statistics, Nonparametric; Treatment Outcome; Ultraviolet Therapy

The cholesterol esterifying enzyme, lecithin:cholesterol acyltransferase (LCAT), plays a key role in HDL maturation and remodeling. Myeloperoxidase (MPO) may compromise LCAT enzymatic activity. We tested the extent to which plasma LCAT activity is altered in acute myocardial infarction (MI) in conjunction with abnormal MPO levels. We also assessed the impact of LCAT and MPO on newly developed major adverse cardiovascular events (MACE).. Two-hundred one consecutive patients referred for acute chest pain of whom 134 had MI (95 with ST-elevation) participated. Forty-five new MACE were ascertained during 1203 (range 13-1745) days of follow-up among 185 patients. Plasma LCAT activity was measured using an exogenous substrate assay. MPO mass was assayed by chemiluminescent microparticle immunoassay.. Plasma LCAT activity was decreased by 15%, coinciding with 7-fold increased MPO levels in acute MI patients vs. patients with non-cardiac chest pain (p < 0.001 for both; correlation: r = -0.343, p < 0.001). MI at admission was associated independently with both lower plasma LCAT activity and higher MPO (age- and sex-adjusted odds ratio per 1 SD increment: 0.46 (95% CI, 0.31-0.68), p < 0.001 and 7.58 (95% CI, 3.34-17.11), p < 0.001, respectively). In an analysis with LCAT and MPO together these associations were modestly attenuated. MPO mass (hazard ratio: 1.59 (95% CI, 1.15-2.19), p = 0.004), but not LCAT activity (hazard ratio: 0.87 (95% CI, 0.65-1.19), p = 0.39), predicted newly manifest MACE.. In acute MI patients, plasma LCAT activity is decreased coinciding with increased MPO levels. Higher MPO but not lower LCAT activity prospectively predicts adverse cardiac outcome.

Topics: Aged; Cardiovascular Diseases; Female; Humans; Incidence; Male; Middle Aged; Myocardial Infarction; Peroxidase; Phosphatidylcholine-Sterol O-Acyltransferase

Lipoxins (LXs) are proresolving and anti-inflammatory eicosanoids whose role in chronic heart failure (CHF) pathogenesis has never been investigated. This study evaluated levels of LXs in CHF patients, its relationship with disease severity and correlation with established CHF biomarkers. The effect of low-dose aspirin [acetylsalicylic acid (ASA)] on the levels of LXs was also studied.. Lipoxin A4 (LXA4 ), 15-epi-lipoxin A4 (15-epi-LXA4 ) and myeloperoxidase (MPO) concentration and activity were evaluated by immunoenzymatic and spectrophotometric assays in 34 CHF patients [New York Heart Association (NYHA) functional class I to IV]. B-type natriuretic peptide (BNP), troponin, myoglobin, C-reactive protein (CRP) and uric acid (UA) were also analyzed.. Patients were stratified into mild-to-moderate CHF (NYHA, classes I and II) and severe CHF (NYHA classes III and IV). Severe patients had lower plasma LXA4 (0·262 ± 0·034 vs. 0·362 ± 0·039 ng/mL, P < 0·05) and decreased urinary 15-epi-LXA4 levels (2·28 ± 0·44 vs. 4·88 ± 1·03 μg/day, P < 0·05) besides exhibiting increased plasma BNP (1464 ± 442 vs. 555 ± 162 pg/mL, P < 0·05) and MPO activity (45·15 ± 11·56 vs. 15·90 ± 2·80 μmol/min/mg protein, P < 0·05). Plasma LXA4 was inversely correlated with BNP, troponin, myoglobin, CRP, UA and MPO activity. ASA treatment was associated with higher urinary excretion of 15-epi-LXA4 (7·70 ± 1·48 vs. 2·06 ± 0·30 μg/day, P < 0·05) in mild-to-moderate CHF patients and lower BNP levels in both groups.. Higher severity of CHF is associated with reduced levels of LXs. Plasma LXA4 appears to be a valuable marker for risk stratification in CHF. Furthermore, the ASA-related increase in urinary 15-epi-LXA4 suggests enhanced renal synthesis of this eicosanoid and may represent a disregarded benefit of ASA.

Topics: Aged; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Biomarkers; Cardiovascular Diseases; Chronic Disease; Female; Glomerular Filtration Rate; Heart Failure; Humans; Inflammation; Leukocyte Count; Lipoxins; Male; Peroxidase; Risk Factors

Major depressive disorder (MDD) is accompanied with an imbalance in the immune system and cardiovascular impairments, such as atherosclerosis. Several mechanisms have been pointed out to underlie this rather unexpected association, and among them the activity of myeloperoxidase (MPO). The aim of our study was to find compounds that inhibit both MPO and serotonin transporter (SERT) for treating MDD associated with cardiovascular diseases.. SERT inhibition was assessed with measuring of [(3) H]-serotonin uptake using HEK-293 MSR cells. MPO inhibition was determined by taurine chloramine test on 3-(aminoalkyl)-5-fluoroindole derivatives and on clinically relevant antidepressants. All kinetic measurements were performed using a temperature-controlled stopped-flow apparatus (model SX-18 MV). Promising lead compounds were docked onto SERT 3D structure modelled using the LeuT structure complexed to tryptophan (PDB code 3F3A). Their toxicological profile was also assessed.. 3-(aminoalkyl)-5-fluoroindole derivative with 5 carbons on the side chain and paroxetine showed the best activity on both MPO and SERT at the nanomolar range. Paroxetine was found to be the first irreversible MPO inhibitor at nanomolar concentrations.. Our results put forward the first hybrid molecule (compound 25) and drug (paroxetine) that can be especially used in MDD associated with inflammatory syndrome.

Topics: Antidepressive Agents; Cardiovascular Diseases; Cell Line; Depressive Disorder, Major; HEK293 Cells; Humans; Indoles; Inflammation; Peroxidase; Selective Serotonin Reuptake Inhibitors; Serotonin; Serotonin Plasma Membrane Transport Proteins

The phagocytic enzyme myeloperoxidase (MPO) acts as a front-line defender against microorganisms. However, increased MPO levels have been found to be associated with complex and calcified atherosclerotic lesions and incident cardiovascular disease. Therefore, this study aimed to investigate a predictive role of MPO, a biomarker of inflammation and oxidative stress, for total and cardiovascular mortality in patients referred to coronary angiography.. MPO plasma concentrations along with eight MPO polymorphisms were determined in 3036 participants of the Ludwigshafen Risk and Cardiovascular Health study (median follow-up 7.75 years). MPO concentrations were positively associated with age, diabetes, smoking, markers of systemic inflammation (interleukin-6, fibrinogen, C-reactive protein, serum amyloid A) and vascular damage (vascular cellular adhesion molecule-1 and intercellular adhesion molecule-1) but negatively associated with HDL-cholesterol and apolipoprotein A-I. After adjustment for cardiovascular risk factors MPO concentrations in the highest versus the lowest quartile were associated with a 1.34-fold risk (95% CI: 1.09-1.67) for total mortality. In the adjusted model the hazard ratio for cardiovascular mortality in the highest MPO quartile was 1.42 (95% CI: 1.07-1.88). Five MPO polymorphisms were positively associated with MPO concentrations but not with mortality. Using Mendelian randomization, we did not obtain evidence for a causal association of MPO with either total or cardiovascular mortality.. MPO concentrations but not genetic variants at the MPO locus are independently associated with risk for total and cardiovascular mortality in coronary artery disease patients.

Topics: Biomarkers; Cardiovascular Diseases; Coronary Angiography; Female; Humans; Male; Middle Aged; Peroxidase; Polymorphism, Genetic; Predictive Value of Tests; Risk

Oxidative stress and oxidized high-density lipoprotein (HDL) are implicated as risk factors for cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Yet, how HDL is oxidized and rendered dysfunctional in SLE remains unclear. Neutrophil extracellular traps (NETs), the levels of which are elevated in lupus, possess oxidant-generating enzymes, including myeloperoxidase (MPO), NADPH oxidase (NOX), and nitric oxide synthase (NOS). We hypothesized that NETs mediate HDL oxidation, impairing cholesterol efflux capacity (CEC).. Plasma MPO levels and CEC activity were examined in controls and lupus patients, and 3-chlorotyrosine (MPO specific) and 3-nitrotyrosine (derived from reactive nitrogen species) were quantified in human HDL. Multivariable linear models were used to estimate and test differences between groups. HDL was exposed to NETs from control and lupus neutrophils in the presence or absence of MPO, NOX, NOS inhibitors, and chloroquine (CQ). Murine HDL oxidation was quantified after NET inhibition in vivo.. SLE patients displayed higher MPO levels and diminished CEC compared to controls. SLE HDL had higher 3-nitrotyrosine and 3-chlorotyrosine content than control HDL, with site-specific oxidation signatures on apolipoprotein A-I. Experiments with human and murine NETs confirmed that chlorination was mediated by MPO and NOX, and nitration by NOS and NOX. Mice with lupus treated with the NET inhibitor Cl-amidine displayed significantly decreased HDL oxidation. CQ inhibited NET formation in vitro.. Active NOS, NOX, and MPO within NETs significantly modify HDL, rendering the lipoprotein proatherogenic. Since NET formation is enhanced in SLE, these findings support a novel role for NET-derived lipoprotein oxidation in SLE-associated CVD and identify additional proatherogenic roles of neutrophils and putative protective roles of antimalarials in autoimmunity.

Topics: Adult; Animals; Cardiovascular Diseases; Female; Humans; Lipoproteins, HDL; Lupus Erythematosus, Systemic; Male; Mice; Middle Aged; NADPH Oxidases; Neutrophils; Nitric Oxide Synthase; Oxidation-Reduction; Oxidative Stress; Peroxidase

In this work, chronoamperometric myelo-peroxidase (MPO) detection was accomplished using immunofunctionalized magnetic microparticles (MPs), disposable carbon screen-printed electrodes (C-SPEs), and a ready-to-use commercially available tetramethylbenzidine (TMB)-based enzymatic substrate. In order to reach the limit of detection (LOD) needed to study real blood serum samples, assay performance was additionally improved by exploiting CNT wiring, which amplified the signal and decreased the LOD. The optimized assay can be performed in 30 min and yields LODs of 6 and 55 ng mL(-1) in PBS and undiluted human serum, respectively, making it useful for the identification of patients at risk of cardiovascular disease. These results demonstrate that electrode nanostructuring can be accomplished "post-assay," which favors the development of enhanced magneto immunosensors based on the exploitation of cheap and simple SPE devices.

Topics: Benzidines; Calibration; Carbon; Cardiovascular Diseases; Electrochemistry; Electrodes; Humans; Immunoassay; Limit of Detection; Magnetics; Nanotechnology; Nanotubes, Carbon; Peroxidase; Spectrophotometry; Temperature

Genetics can be used to predict drug effects and generate hypotheses around alternative indications. To support Losmapimod, a p38 mitogen-activated protein kinase inhibitor in development for acute coronary syndrome, we characterized gene variation in MAPK11/14 genes by exome sequencing and follow-up genotyping or imputation in participants well-phenotyped for cardiovascular and metabolic traits.. Investigation of genetic variation in MAPK11 and MAPK14 genes using additive genetic models in linear or logistic regression with cardiovascular, metabolic, and biomarker phenotypes highlighted an association of RS2859144 in MAPK14 with myeloperoxidase in a dyslipidemic population (Genetic Epidemiology of Metabolic Syndrome Study), P=2.3×10(-6)). This variant (or proxy) was consistently associated with myeloperoxidase in the Framingham Heart Study and Cardiovascular Health Study studies (replication meta-P=0.003), leading to a meta-P value of 9.96×10(-7) in the 3 dyslipidemic groups. The variant or its proxy was then profiled in additional population-based cohorts (up to a total of 58 930 subjects) including Cohorte Lausannoise, Ely, Fenland, European Prospective Investigation of Cancer, London Life Sciences Prospective Population Study, and the Genetics of Obesity Associations study obesity case-control for up to 40 cardiovascular and metabolic traits. Overall analysis identified the same single nucleotide polymorphisms to be nominally associated consistently with glomerular filtration rate (P=0.002) and risk of obesity (body mass index ≥30 kg/m(2), P=0.004).. As myeloperoxidase is a prognostic marker of coronary events, the MAPK14 variant may provide a mechanistic link between p38 map kinase and these events, providing information consistent with current indication of Losmapimod for acute coronary syndrome. If replicated, the association with glomerular filtration rate, along with previous biological findings, also provides support for kidney diseases as alternative indications.

Topics: Adult; Aged; Cardiovascular Diseases; Dyslipidemias; Exome; Female; Genotype; Humans; Linear Models; Logistic Models; Male; Metabolic Syndrome; Middle Aged; Mitogen-Activated Protein Kinase 11; Mitogen-Activated Protein Kinase 14; Obesity; Peroxidase; Polymorphism, Single Nucleotide; Prognosis; Risk Factors; Sequence Analysis, DNA

High-density lipoprotein (HDL) plays a key role in protecting against atherosclerosis. In cardiovascular disease, HDL can be nitrated and chlorinated by myeloperoxidase (MPO). In this study, we discovered that MPO-oxidized HDL is dysfunctional in promoting endothelial repair compared to normal HDL. Proliferation assay, wound healing, and transwell migration experiments showed that MPO-oxidized HDL was associated with a reduced stimulation of endothelial cell (EC) proliferation and migration. In addition, we found that Akt and ERK1/2 phosphorylation in ECs was significantly lower when ECs were incubated with oxidized HDL compared with normal HDL. To further determine whether oxidized HDL diminished EC migration through the PI3K/Akt and MEK/ERK pathways, we performed experiments with inhibitors of both these pathways. The transwell experiments performed in the presence of these inhibitors showed that the migration capacity was reduced and the differences observed between normal HDL and oxidized HDL were diminished. Furthermore, to study the effects of oxidized HDL on endothelial cells in vivo, we performed a carotid artery electric injury model on nude mice injected with either normal or oxidized HDL. Oxidized HDL inhibited reendothelialization compared to normal HDL in vivo. These findings implicate a key role for MPO-oxidized HDL in the pathogenesis of cardiovascular disease.

Topics: Animals; Cardiovascular Diseases; Catalysis; Cell Movement; Cell Proliferation; Endothelial Cells; Endothelium; Halogenation; Humans; Lipoproteins, HDL; MAP Kinase Signaling System; Mice; Nitrates; Oxidation-Reduction; Peroxidase; Proto-Oncogene Proteins c-akt

Topics: Adiponectin; Arginine; Biomarkers; Cardiovascular Diseases; Cystatin C; Endothelins; Glycopeptides; Humans; MicroRNAs; Natriuretic Peptide, Brain; Peptide Fragments; Peroxidase; Predictive Value of Tests; Troponin

Elevated levels of advanced oxidation protein products have been described in several chronic inflammatory diseases, like chronic renal insufficiency, rheumatoid arthritis, and atherosclerosis. Recent findings revealed that advanced oxidation protein products are inhibitors of the major high-density lipoprotein receptor, scavenger receptor class B, type 1 (SR-BI). Here, we investigated which oxidation-induced structural alterations convert plasma albumin into a high-density lipoprotein-receptor inhibitor.. Exposure of albumin to the physiological oxidant, hypochlorous acid, generated high-affinity SR-BI ligands. Protection of albumin-lysine residues before exposure to hypochlorous acid as well as regeneration of N-chloramines after oxidation of albumin completely prevented binding of oxidized albumin to SR-BI, indicating that modification of albumin-lysine residues is required to generate SR-BI ligands. Of particular interest, N-chloramines within oxidized albumin promoted irreversible binding to SR-BI, resulting in permanent receptor blockade. We observed that the SR-BI inhibitory activity of albumin isolated from chronic kidney disease patients correlated with the content of the myeloperoxidase-specific oxidation product 3-chlorotyrosine and was associated with alterations in the composition of high-density lipoprotein.. Given that several potential atheroprotective activities of high-density lipoprotein are mediated by SR-BI, the present results raise the possibility that oxidized plasma albumin, through permanent SR-BI blockade, contributes to the pathophysiology of cardiovascular disease.

Topics: Animals; Cardiovascular Diseases; CD36 Antigens; CHO Cells; Cricetinae; Cricetulus; Humans; Hypochlorous Acid; Kidney Failure, Chronic; Lipoproteins, HDL; Mice; Mice, Inbred BALB C; Peroxidase; Receptors, Lipoprotein; Serum Albumin

Mercury(II) is a highly toxic environmental pollutant leading to oxidative stress in animals and human beings. In this study we aimed to investigate the possible protective effect of a water-soluble polysaccharide (AEP-w1) from the root bark of Aralia elata against experimental mercury(II)-induced cardiovascular oxidative injury in rat model. The results showed that delayed AEP-w1 supplement to HgCl2-treated mice not only decreased serum lactate dehydrogenase (LDH) and tumor necrosis factor-α (TNF-α) levels, but also increased serum nitric oxide (NO) metabolite levels and antioxidant capacity. Moreover, AEP-w1 administration to HgCl2-treated mice significantly decreased malondialdehyde (MDA) level and myeloperoxidase (MPO) activity and increased superoxide dismutase (SOD) and catalase (CAT) activities, along with glutathione (GSH) level in rat cardiac tissue. In addition, elevated serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cr) levels in the saline-treated Hg group were also reversed by AEP-w1 treatment. Therefore, the present study demonstrates that alleviation of HgCl2-induced oxidative injury in rat by AEP-w1 contributes to better understanding of its beneficial effect against cardiovascular diseases.

Topics: Alanine Transaminase; Animals; Aralia; Aspartate Aminotransferases; Blood Urea Nitrogen; Cardiovascular Diseases; Catalase; Female; L-Lactate Dehydrogenase; Male; Malondialdehyde; Mercuric Chloride; Nitric Oxide; Oxidative Stress; Peroxidase; Plant Roots; Polysaccharides; Rats; Rats, Wistar; Superoxide Dismutase; Tumor Necrosis Factor-alpha

Myeloperoxidase is a strong oxidant stored in primary granules of neutrophils with potent antibacterial and proatherogenic properties. Myeloperoxidase has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the relationship of myeloperoxidase to health outcomes in COPD is not well known. We measured serum myeloperoxidase levels from 4,677 subjects with mild to moderate airflow limitation in the Lung Health Study. Using a Cox proportional hazards model, we determined the relationship of serum myeloperoxidase concentration to the risk of all-cause and disease specific causes of mortality. We found that serum myeloperoxidase concentrations were significantly related to accelerated decline in forced expiratory volume in 1 second (FEV1) over 11 years of follow-up (p<0.0001), and this association persisted after adjustments for age, sex, race, baseline FEV1, and smoking status (p = 0.048). Serum myeloperoxidase concentrations were also associated with increased risk of cardiovascular mortality (p = 0.036). Individuals in the highest quintile of myeloperoxidase had a hazard ratio of cardiovascular mortality of 1.90 (95% confidence interval 1.00-3.58; p = 0.049) compared with those in the lowest quintile, which was particularly notable in patients who continued to smoke (adjusted p-value of 0.0396). However, serum myeloperoxidase concentration was not related to total mortality, respiratory mortality, or deaths from malignancies. In conclusion, increased serum myeloperoxidase levels are associated with rapid lung function decline and poor cardiovascular outcomes in COPD patients, which support the emerging role of myeloperoxidase in the pathogenesis of COPD progression and cardiovascular disease.

Topics: Adult; Cardiovascular Diseases; Cohort Studies; Disease Progression; Female; Forced Expiratory Volume; Humans; Male; Middle Aged; Peroxidase; Proportional Hazards Models; Pulmonary Disease, Chronic Obstructive

Homocysteine (HCys), a sulfur-containing amino acid, is formed during the metabolism of methionine. An imbalance between the rate of production and the use of HCys during methionine metabolism can result in an increase in the plasma and urinary levels of HCys. HCys has been shown to be toxic to vascular endothelial cells through several pathways. Many earlier clinical studies have revealed an association between plasma HCys and cardiovascular and other diseases. In contrast, estrogens are suggested to lower the risk of cardiovascular disease. Several studies indicate that estrogen metabolites could be responsible for cardiovascular protection. It has been demonstrated that electrophilic estrogen quinones, E1(E2)-2,3-Q and E1(E2)-3,4-Q, can alkylate DNA as well as form conjugates with glutathione. I hypothesize that estrogen quinones generated in situ by oxidative enzymes, metal ions, or molecular oxygen can interact with HCys to form conjugates. This in turn could lower the levels of toxic HCys as well as quenching the reactive estrogen quinones, resulting in cardiovascular protective effects. To test the feasibility of a protective estrogen-HCys pathway, estrogen quinones were treated with HCys. Tandem mass spectrometry analysis of the assay mixture shows the formation of estrogen-HCys conjugates. Furthermore, incubation of catechol estrogens with myeloperoxidase (MPO) in the presence of HCys resulted in the formation of respective estrogen-HCys conjugates. The identities of estrogen-HCys conjugates in MPO assay extracts were confirmed by comparing them to pure synthesized estrogen-HCys standards. I propose that through conjugation estrogens could chemically regulate HCys levels; moreover these conjugates could be used as potential biomarkers in determining health.

Topics: Alkylation; Cardiotonic Agents; Cardiovascular Diseases; DNA; Estradiol Congeners; Estrogens; Estrogens, Catechol; Glutathione; Homocysteine; Mass Spectrometry; Oxidation-Reduction; Peroxidase; Quinones

Phagocyte-derived myeloperoxidase (MPO) and pro-inflammatory high density lipoprotein (HDL) associate with rheumatoid arthritis (RA), but the link between MPO and HDL has not been systematically examined. In this study, we investigated whether MPO can oxidise HDL and determined MPO-specific oxidative signature by apoA-1 by peptide mapping in RA subjects with and without known cardiovascular disease (CVD).. Two MPO oxidation products, 3-chlorotyrosine and 3-nitrotyrosine, were quantified by tandem mass spectrometry (MS/MS) in in vitro model system studies and in plasma and HDL derived from healthy controls and RA subjects. MPO levels and cholesterol efflux were determined. Site-specific nitration and chlorination of apoA-1 peptides were quantified by MS/MS.. RA subjects demonstrated higher levels of MPO, MPO-oxidised HDL and diminished cholesterol efflux. There was marked increase in MPO-specific 3-chlorotyrosine and 3-nitrotyrosine content in HDL in RA subjects consistent with specific targeting of HDL, with increased nitration in RA subjects with CVD. Cholesterol efflux capacity was diminished in RA subjects and correlated inversely with HDL 3-chlorotyrosine suggesting a mechanistic role for MPO. Nitrated HDL was elevated in RACVD subjects compared with RA subjects without CVD. Oxidative peptide mapping revealed site-specific unique oxidation signatures on apoA-1 for RA subjects with and without CVD.. We report an increase in MPO-mediated HDL oxidation that is regiospecific in RA and accentuated in those with CVD. Decreased cholesterol efflux capacity due to MPO-mediated chlorination is a potential mechanism for atherosclerosis in RA and raises the possibility that oxidant resistant forms of HDL may attenuate this increased risk.

Topics: Adult; Aged; Apolipoprotein A-I; Arthritis, Rheumatoid; Cardiovascular Diseases; Case-Control Studies; Cholesterol; Female; Halogenation; Humans; Lipoproteins, HDL; Male; Middle Aged; Oxidation-Reduction; Peptide Mapping; Peroxidase; Tandem Mass Spectrometry; Tyrosine

Myeloperoxidase (MPO) is involved in a multitude of inflammatory processes involving oxidative modification of soluble components and cellular surfaces. Thus, MPO plays a key role in promoting atherosclerosis via oxidative stress by modification of both high- and low-density lipoprotein and production of other bioactive molecules. A polymorphism (MPO 463G>A, rs2333227) results in different expression rates of MPO. We aimed to assess whether MPO could be of clinical use as a risk marker for vascular disease in a high-risk group.. Plasma MPO levels of 406 patients suffering from peripheral arterial disease (PAD) were measured on an Abbott Architect i2000sr and grouped into patients with high (>115 ng/mL) and low (< 115 ng/mL) MPO levels. Genotyping of rs2333227 was performed on an ABI TaqMan 7900HT RT-PCR thermocycler.. The relative risk of major adverse cardiovascular events (MACE) for patients with high plasma MPO is 1.2 (95%CI: 1.038-1.377, P < 0.05), initial event-free periods in male patients are significantly longer in patients with MPO <115 ng/mL (mean = 875 days compared with mean = 734 days, P < 0.05) In smokers, an increased hazard ratio was computed for patients with high MPO levels (HR = 3.127, 95%CI: 1.258-7.772, P < 0.05). Effects of MPO [-463A] allele on initial MACE-free intervals did not persist after multivariate analysis.. Hence, we suggest consideration of plasma MPO for risk stratification of MACE in patients with PAD. In contrast, MPO-463G>A is not an independent risk factor for MACE in patients suffering from PAD.

Topics: Aged; Atherosclerosis; Biomarkers; Cardiovascular Diseases; Female; Genotype; Humans; Male; Middle Aged; Peripheral Arterial Disease; Peroxidase; Polymorphism, Single Nucleotide; Predictive Value of Tests; Risk Factors

A fatty meal may represent a challenge of in vivo acute inflammatory reaction. We evaluated the acute effects of a standardised fatty meal administration on leukocytes and platelets and on their interactions on 61 subjects at different degree of cardiovascular risk, without any clinical event. Before and 2 hours after a fatty meal, blood cells were counted and markers of leukocyte (intracellular myeloperoxidase [MPO] and Mac-1) and platelet (P-selectin and microparticles) activation and mixed platelet-leukocyte conjugates measured by flow-cytometry. After the fatty meal, both white blood cell and platelet count significantly increased, more markedly in subjects with lower cardiovascular risk score. Mac-1 expression too increased (from 32.2 ± 27.2% to 45.6 ± 29.0%, p=0.0016), while MPO decreased (from 83.1 ± 16.3% to 64.5 ± 23.1%, p<0.0001). A trend for increased platelet activation and interaction with leukocytes was also observed. Women were more markedly susceptible to fatty meal challenge, as compared to men, while age did not seem to affect any cell response to fatty meal. Waist-to-hip ratio and body mass index influenced polymorphonuclear cells (PMN) degranulation and platelet count increase, respectively. Cellular responses to the fatty meal, in particular PMN degranulation, were attenuated in subjects at higher degree of cardiovascular risk, who showed a basal mild inflammatory activation status. In conclusion, a fatty meal consumption may represent a model of acute inflammatory response and appears to be modulated by different demographic and cardiovascular risk degree. This model could be applied to study the effect of food-derived antioxidants or nutritional supplements, but its relevance remains to be demonstrated.

Topics: Adult; Blood Platelets; Body Mass Index; Cardiovascular Diseases; Cell Adhesion; Cell Degranulation; Cell-Derived Microparticles; Dietary Fats; Female; Humans; Inflammation Mediators; Leukocytes; Macrophage-1 Antigen; Male; Middle Aged; P-Selectin; Peroxidase; Platelet Activation; Postprandial Period; Risk; Sex Factors

The authors conducted a cross-sectional study to assess the relation between arsenic exposure from drinking water and plasma levels of markers of systemic inflammation and endothelial dysfunction (matrix metalloproteinase-9, myeloperoxidase, plasminogen activator inhibitor-1, soluble E-selectin, soluble intercellular adhesion molecule-1 (ICAM-1), and soluble vascular adhesion molecule-1 (VCAM-1)) using baseline data from 668 participants (age, >30 years) in the Health Effects of Arsenic Longitudinal Study in Bangladesh (2007-2008). Both well water arsenic and urinary arsenic were positively associated with plasma levels of soluble VCAM-1. For every 1-unit increase in log-transformed well water arsenic (ln μg/L) and urinary arsenic (ln μg/g creatinine), plasma soluble VCAM-1 was 1.02 (95% confidence interval: 1.01, 1.03) and 1.04 (95% confidence interval: 1.01, 1.07) times greater, respectively. There was a significant interaction between arsenic exposure and higher body mass index, such that the increased levels of plasminogen activator inhibitor-1 and soluble VCAM-1 associated with arsenic exposure were stronger among people with higher body mass index. The findings indicate an effect of chronic arsenic exposure from drinking water on vascular inflammation and endothelial dysfunction that could be modified by body mass index and also suggest a potential mechanism underlying the association between arsenic exposure and cardiovascular disease.

Topics: Adult; Arsenic; Bangladesh; Biomarkers; Body Mass Index; Cardiovascular Diseases; Cross-Sectional Studies; Drinking Water; E-Selectin; Endothelium, Vascular; Environmental Exposure; Female; Humans; Inflammation; Intercellular Adhesion Molecule-1; Linear Models; Longitudinal Studies; Male; Matrix Metalloproteinase 9; Middle Aged; Peroxidase; Plasminogen Activator Inhibitor 1; Prospective Studies; Vascular Cell Adhesion Molecule-1; Water Pollutants, Chemical; Water Pollution, Chemical

Obesity is associated with a state of chronic low-grade inflammation. Myeloperoxidase (MPO) plays an important role in the initiation and progression of acute and chronic inflammatory diseases, such as cardiovascular disease (CVD). The objectives of the current study were to evaluate plasma MPO levels in prepubertal obese children and to determine whether MPO could be an early biomarker of inflammation and CVD risk.. In a prospective multicenter case-control study paired by age and sex of 446 Caucasian prepubertal children ages 6-12 years, 223 normal-weight and 223 obese children were recruited. Blood pressure, waist circumference, weight, and height were measured. In addition to MPO, glucose, insulin, metabolic lipid parameters, oxidized low-density lipoproteins, adiponectin, leptin, resistin, C-reactive protein (CRP), interleukin 6, tumor necrosis factor α, matrix metalloproteinase-9 (MMP-9), and plasminogen activator inhibitor 1 were determined.. We found that MPO was elevated in prepubertal obese children and that this enzyme was associated with such proinflammatory and cardiovascular risk biomarkers as CRP, MMP-9, and resistin. Insulin resistance calculated by the homeostatic assessment model was the best predictor of MPO.. MPO is an early biomarker of inflammation associated with CVD risk in obese children at the prepubertal age.

Topics: Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Case-Control Studies; Child; Female; Humans; Inflammation; Male; Obesity; Peroxidase; Prospective Studies; Resistin; Risk Factors

Advanced oxidation protein products (AOPP) is widely used as a uremic biomarker, especially for cardiovascular disease. However, it has not been determined whether it is better to measure AOPP in plasma or serum. In this cross-sectional study, which included 102 patients undergoing maintenance hemodialysis, fibrinogen-free serum and defibrinated plasma samples were prepared. AOPP levels from fibrinogen-free samples displayed a stronger correlation with myeloperoxidase activity and levels of C-reactive protein, interleukin-6 and tumor necrosis factor-alpha, as well as prevalent cardiovascular disease, than AOPP levels obtained from plasma samples. These results demonstrated that fibrinogen interferes with the measurement of AOPP.

Topics: Biomarkers; Blood Specimen Collection; C-Reactive Protein; Cardiovascular Diseases; Cross-Sectional Studies; Female; Fibrinogen; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Oxidation-Reduction; Oxidative Stress; Peroxidase; Renal Dialysis; Tumor Necrosis Factor-alpha

Urate and myeloperoxidase (MPO) are associated with adverse outcomes in cardiovascular disease. In this study, we assessed whether urate is a likely physiological substrate for MPO and if the products of their interaction have the potential to exacerbate inflammation. Urate was readily oxidized by MPO and hydrogen peroxide to 5-hydroxyisourate, which decayed to predominantly allantoin. The redox intermediates of MPO were reduced by urate with rate constants of 4.6 × 10(5) M(-1) s(-1) for compound I and 1.7 × 10(4) M(-1) s(-1) for compound II. Urate competed with chloride for oxidation by MPO and at hyperuricemic levels is expected to be a substantive substrate for the enzyme. Oxidation of urate promoted super-stoichiometric consumption of glutathione, which indicates that it is converted to a free radical intermediate. In combination with superoxide and hydrogen peroxide, MPO oxidized urate to a reactive hydroperoxide. This would form by addition of superoxide to the urate radical. Urate also enhanced MPO-dependent consumption of nitric oxide. In human plasma, stimulated neutrophils produced allantoin in a reaction dependent on the NADPH oxidase, MPO and superoxide. We propose that urate is a physiological substrate for MPO that is oxidized to the urate radical. The reactions of this radical with superoxide and nitric oxide provide a plausible link between urate and MPO in cardiovascular disease.

Topics: Allantoin; Cardiovascular Diseases; Humans; Hydrogen Peroxide; Hyperuricemia; Inflammation; NADPH Oxidases; Neutrophils; Oxidation-Reduction; Peroxidase; Substrate Specificity; Superoxides; Uric Acid

The nitric oxide synthase inhibitor asymmetrical dimethylarginine (ADMA) and the leukocyte-derived hemoprotein myeloperoxidase (MPO) are associated with cardiovascular diseases. Activation of monocytes and polymorphonuclear neutrophils (PMNs) with concomitant release of MPO is regulated in a nitric oxide-dependent fashion. The aim of the study was to investigate a potential 2-way interaction between ADMA and MPO.. Ex vivo, ADMA uptake by isolated human PMNs, the principal source of MPO in humans, significantly impaired nitric oxide synthase activity determined by gas chromatography-mass spectrometry. In humans, short-term ADMA infusion (0.0125 mg · kg(-1) · min(-1)) significantly increased MPO plasma concentrations. Functionally, PMN exposure to ADMA enhanced leukocyte adhesion to endothelial cells, augmented NADPH oxidase activity, and stimulated PMN degranulation, resulting in release of MPO. In vivo, a 28-day ADMA infusion (250 μmol · kg(-1) · d(-1)) in C57Bl/6 mice significantly increased plasma MPO concentrations, whereas this ADMA effect on MPO was attenuated by human dimethylarginine dimethylaminohydrolase1 (hDDAH1) overexpression. Moreover, the MPO-derived reactive molecule hypochlorous acid impaired recombinant hDDAH1 activity in vitro. In MPO(-/-) mice, the lipopolysaccharide-induced increase in systemic ADMA concentrations was abrogated.. ADMA profoundly impairs nitric oxide synthesis of PMNs, resulting in increased PMN adhesion to endothelial cells, superoxide generation, and release of MPO. In addition, MPO impairs DDAH1 activity. Our data reveal an ADMA-induced cycle of PMN activation, enhanced MPO release, and subsequent impairment of DDAH1 activity. These findings not only highlight so far unrecognized cytokine-like properties of ADMA but also identify MPO as a regulatory switch for ADMA bioavailability under inflammatory conditions.

Topics: Amidohydrolases; Animals; Arginine; Cardiovascular Diseases; Dose-Response Relationship, Drug; Female; HL-60 Cells; Humans; In Vitro Techniques; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Models, Animal; Neutrophils; Nitric Oxide; Nitric Oxide Synthase Type III; Peroxidase; Signal Transduction; Superoxides

CVD in obesity and T2DM are associated with endothelial activation, elevated plasma vascular inflammation markers and a prothrombotic state. We examined the contribution of FFA to these abnormalities following a 48-hour physiological increase in plasma FFA to levels of obesity and diabetes in a group of healthy subjects.. 40 non-diabetic subjects (age = 38 +/- 3 yr, BMI = 28 +/- 1 kg/m2, FPG = 95 +/- 1 mg/dl, HbA1c = 5.3 +/- 0.1%) were admitted twice and received a 48-hour infusion of normal saline or low-dose lipid. Plasma was drawn for intracellular (ICAM-1) and vascular (VCAM-1) adhesion molecules-1, E-selectin (sE-S), myeloperoxidase (MPO) and total plasminogen inhibitor-1 (tPAI-1). Insulin sensitivity was measured by a hyperglycemic clamp (M/I).. Lipid infusion increased plasma FFA to levels observed in obesity and T2DM and reduced insulin sensitivity by 27% (p = 0.01). Elevated plasma FFA increased plasma markers of endothelial activation ICAM-1 (138 +/- 10 vs. 186 +/- 25 ng/ml), VCAM-1 (1066 +/- 67 vs. 1204 +/- 65 ng/ml) and sE-S (20 +/- 1 vs. 24 +/- 1 ng/ml) between 13-35% and by > or = 2-fold plasma levels of myeloperoxidase (7.5 +/- 0.9 to 15 +/- 25 ng/ml), an inflammatory marker of future CVD, and tPAI-1 (9.7 +/- 0.6 to 22.5 +/- 1.5 ng/ml), an indicator of a prothrombotic state (all p < or = 0.01). The FFA-induced increase was independent from the degree of adiposity, being of similar magnitude in lean, overweight and obese subjects.. An increase in plasma FFA within the physiological range observed in obesity and T2DM induces markers of endothelial activation, vascular inflammation and thrombosis in healthy subjects. This suggests that even transient (48-hour) and modest increases in plasma FFA may initiate early vascular abnormalities that promote atherosclerosis and CVD.

Topics: Adult; Blood Glucose; Cardiovascular Diseases; E-Selectin; Endothelium, Vascular; Fatty Acids, Nonesterified; Female; Glycated Hemoglobin; Humans; Insulin; Intercellular Adhesion Molecule-1; Male; Peroxidase; Plasminogen Activator Inhibitor 1; Reference Values; Vascular Cell Adhesion Molecule-1

Scavenging of the vasodilator nitric oxide by myeloperoxidase activity in the vasculature may contribute to hypertension. Because hydrogen peroxide is a cosubstrate of myeloperoxidase, hyperglycemia-induced oxidative stress may strengthen the relationship between myeloperoxidase and blood pressure. We investigated this relationship and its modification by hyperglycemia and oxidative stress in a population-based cohort of elderly subjects with normal glucose metabolism (n=267), impaired glucose metabolism (n=189), and type 2 diabetes (n=290). In an age- and sex-adjusted linear regression model, plasma myeloperoxidase was positively associated with systolic blood pressure (2.10 mm Hg per 1 SD increment of myeloperoxidase [95% CI: 0.66 to 3.54]), and this association was stronger at higher levels of fasting glucose (0.61 [-1.70 to 2.93], 1.33 [-1.43 to 4.10], and 3.42 [1.01 to 5.82] for increasing tertiles of glucose) and higher plasma levels of oxidized low-density lipoprotein (0.92 [-1.31 to 3.14], 2.00 [-0.71 to 4.70], and 3.58 [0.98 to 6.19] for increasing tertiles of oxidized low-density lipoprotein). Likewise, the relationship between myeloperoxidase and blood pressure was strongest under conditions associated with oxidative stress, like obesity, low high-density lipoprotein cholesterol, metabolic syndrome, and type 2 diabetes. The strength of these associations was only marginally attenuated by adjustment for other cardiovascular risk factors. Our data demonstrate that myeloperoxidase is positively and independently associated with blood pressure, and this association is strongest in subjects with (hyperglycemia-induced) oxidative stress. These observations, together with emerging evidence that myeloperoxidase-derived oxidants contribute to the initiation and propagation of cardiovascular disease, identify myeloperoxidase as a promising target for drug development.

Topics: Aged; Biomarkers; Blood Glucose; Blood Pressure; Blood Pressure Determination; Cardiovascular Diseases; Cohort Studies; Diabetes Mellitus, Type 2; Female; Humans; Hyperglycemia; Hypertension; Linear Models; Male; Multivariate Analysis; Oxidative Stress; Peroxidase; Probability; Prognosis; Proportional Hazards Models; Reference Values; Risk Assessment; Severity of Illness Index

Myeloperoxidase (MPO) is a hemoprotein that is released during inflammation and may lead to irreversible protein and lipid modification, increasing levels of oxidized low density lipoprotein, and promoting athrogenesis. Recently, it has been considered as a risk factor for cardiovascular diseases. Similarly, the measurement of carotid intima-media thickness gives an indication about the degree of atherosclerosis and prediction of clinical cardiovascular events. Elevated white blood cells counts may indicate a state of acute inflammation and follow its progression. Dialysis patients are at a high risk of developing cardiovascular disease compared with healthy subjects. The role of N-terminal pro-brain natriuretic peptide and increased cardiac troponin in identification and prognostication of cardiovascular diseases in end-stage renal disease patients has been investigated. The current study aimed to evaluate plasma MPO and its possible relationship with carotid intima-media thickness, troponin I, N-terminal pro-brain natriuretic peptide (NT-proBNP), and insulin resistance as measured by homeostatic model assessment (HOMA index) in a cohort of Saudi patients who are undergoing hemodialysis (HD) vs. continuous ambulatory peritoneal dialysis for end-stage renal disease. Plasma MPO was significantly higher in patients on continuous ambulatory peritoneal dialysis (CAPD) than in those on HD and in normal subjects (P<0.001). Conversely, NT-proBNP plasma levels were significantly higher in patients on HD (both predialysis and postdialysis) than in those on CAPD (P<0.01) and than normal subjects. Similarly, plasma troponin-I levels were significantly higher in patients on HD compared with those of CAPD and than normal subjects (P<0.001). Plasma troponin-I and NT-proBNP levels were positively correlated in the 3 groups namely those on CAPD, Pre-HD, and post-HD (r: 0.464 and P=0.047; r: 0.330 and P=0.013; and r: 0.452 and P=0.024), respectively. There was no correlation between the MPO level and carotid intima-media thickness (P>0.05). However, plasma MPO level correlated positively with the white blood cell count in patients on CAPD and in those on HD (P<0.05). Our findings suggest an increased oxidative stress in CAPD patients compared with HD patients, while the reported difference in plasma NT-proBNP and troponin-I may be related to the rapid decline of residual renal function in HD and type of membrane used in the HD dialysis procedure itself.

Topics: Adult; Aged; Cardiovascular Diseases; Case-Control Studies; Female; Humans; Inflammation Mediators; Kidney Failure, Chronic; Male; Middle Aged; Natriuretic Peptide, Brain; Peptide Fragments; Peritoneal Dialysis, Continuous Ambulatory; Peroxidase; Renal Dialysis; Risk Factors; Troponin I

Myeloperoxidase (MPO) has been suggested to have a role in atherosclerosis through its strong oxidative capacity. We hypothesized that MPO level may predict clinical outcomes in patients with end-stage renal disease receiving long-term peritoneal dialysis (PD) therapy.. Prospective cohort study.. 236 long-term PD patients were recruited from a single regional dialysis unit in Hong Kong between April 1999 and February 2001.. Level of plasma MPO, analyzed using a sandwich enzyme-linked immunosorbent assay.. Mortality and fatal or nonfatal cardiovascular events at 3 years.. The distribution of MPO levels was skewed with a median of 31.8 μg/L (25th-75th percentiles, 24.4-42.7). There were 69 deaths and 81 cardiovascular events. Adjusting for traditional and nontraditional risk factors and C-reactive protein, cardiac troponin T, and N-terminal pro-brain natriuretic peptide levels, a doubling in plasma MPO level was associated independently with a 46% (95% CI, 1.02-2.08; P = 0.04) and 60% (95% CI, 1.17-2.18; P = 0.003) increase in risks of mortality and cardiovascular events, respectively. Log(2)MPO showed significant additional predictive value for mortality (P = 0.04) and cardiovascular events (P = 0.005) when included in Cox regression models consisting of clinical, demographic, dialysis, echocardiographic, and biochemical parameters, as well as C-reactive protein, cardiac troponin T, and N-terminal pro-brain natriuretic peptide levels.. MPO was measured at a single time and did not reflect changes over time.. These data suggest that plasma MPO level has significant independent and additional prognostic value beyond the standard clinical, biochemical, and echocardiographic parameters and is useful for outcome stratification in long-term PD patients. MPO may be an important mediator of increased cardiovascular risk in patients with end-stage renal disease and warrants further investigation.

Topics: Cardiovascular Diseases; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Hong Kong; Humans; Incidence; Kidney Failure, Chronic; Male; Middle Aged; Oxidative Stress; Peritoneal Dialysis; Peroxidase; Prognosis; Prospective Studies; Survival Rate

It has been well established that diet high in cholesterol and saturated fatty acids could significantly elevate plasma cholesterol levels and also increase the risk of cardiovascular diseases. We hypothesize that repeated systemic Escherichia coli (E. coli) in conjunction with hypercholesterolemia, leads to development of oxidative stress that may affect the development and progression of inflammatory CVD. Swiss albino mice (4 weeks old) were randomly assigned to high cholesterol diet (HCD) or normal laboratory diet (NLD) groups. At 10 weeks of age, mice were inoculated intravenously with E. coli or vehicle for 24 weeks. Serum cholesterol, low density lipoprotein, C reactive protein levels, blood glucose level and selective antioxidant enzymes throughout the systemic infection period in murine aorta, heart and liver during hypercholesterolemia, were examined. Serum cholesterol levels were elevated in HCD-fed mice, compared to NLD. The blood colony forming units (CFU) of E. coli suggested persistence of systemic infection. The antioxidant enzyme levels were elevated in E. coli infected groups as compared to controls. The myeloperoxidase content of aortic tissue was significantly higher in all groups infected with E. coli. Our study suggests that during hypercholesterolemia, repeated systemic E. coli infection induces an endogenous antioxidant response that serves to modulate vascular inflammation leading to cardiovascular diseases.

Topics: Animals; Aorta; Blood Glucose; C-Reactive Protein; Cardiovascular Diseases; Cholesterol; Coronary Vessels; Escherichia coli; Escherichia coli Infections; Hypercholesterolemia; Inflammation; Lipids; Liver; Mice; Oxidative Stress; Oxidoreductases; Peroxidase; Recurrence

Topics: Atherosclerosis; Biomarkers; Cardiovascular Diseases; Child; Child, Preschool; Gene Expression Regulation; Humans; Hypercholesterolemia; Infant; Infant, Newborn; Inflammation; Lipoproteins, LDL; Oxygen; Peroxidase; Signal Transduction

We investigated the effect of comprehensive periodontal therapy on the levels of multiple systemic inflammatory biomarkers.. Thirty patients with severe periodontitis received comprehensive periodontal therapy within a 6-week period. Blood samples were obtained at: 1-week pre-therapy (T1), therapy initiation (T2), treatment completion (T3), and 4 weeks thereafter (T4). We assessed the plasma concentrations of 19 biomarkers using multiplex assays, and serum IgG antibodies to periodontal bacteria using checkerboard immunoblotting. At T2 and T4, dental plaque samples were analysed using checkerboard hybridizations.. At T3, PAI-1, sE-selectin, sVCAM-1, MMP-9, myeloperoxidase, and a composite summary inflammatory score (SIS) were significantly reduced. However, only sE-selectin, sICAM, and serum amyloid P sustained a reduction at T4. Responses were highly variable: analyses of SIS slopes between baseline and T4 showed that approximately 1/3 and 1/4 of the patients experienced a marked reduction and a pronounced increase in systemic inflammation, respectively, while the remainder were seemingly unchanged. Changes in inflammatory markers correlated poorly with clinical, microbiological and serological markers of periodontitis.. Periodontal therapy resulted in an overall reduction of systemic inflammation, but the responses were inconsistent across subjects and largely not sustainable. The determinants of this substantial heterogeneity need to be explored further.

Topics: Adiponectin; Adolescent; Adult; Aged; Alveolar Bone Loss; Antibodies, Bacterial; C-Reactive Protein; Cardiovascular Diseases; Dental Plaque; Dental Scaling; E-Selectin; Female; Humans; Inflammation; Inflammation Mediators; Intercellular Adhesion Molecule-1; Interleukins; Linear Models; Male; Matrix Metalloproteinase 9; Middle Aged; Oral Hygiene; Periodontitis; Peroxidase; Plasminogen Activator Inhibitor 1; Prospective Studies; Serum Amyloid P-Component; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1; Young Adult

Human immunodeficiency virus (HIV)-infected patients are at increased risk of cardiovascular disease, which may be related to chronic inflammation and endothelial dysfunction despite virological control with antiretroviral therapy. The relationship between carotid intima-media thickness (IMT), a surrogate marker for cardiovascular disease, proinflammatory cytokines, and endothelial activation markers has not been fully explored in HIV-infected patients who are receiving antiretroviral therapy.. We conducted a prospective, cross-sectional, observational study of treated HIV-infected patients and healthy control subjects to evaluate the relationship between carotid IMT, proinflammatory cytokines, endothelial activation biomarkers, and metabolic parameters in treated HIV-infected patients, compared with healthy control subjects.. We enrolled 73 HIV-infected patients and 21 control subjects. Common carotid artery and internal carotid artery IMT measurements, as well as tumor necrosis factor-alpha, high-sensitivity C-reactive protein, interleukin-6, myeloperoxidase, and soluble vascular cell adhesion molecule-1 levels were higher in the HIV-infected group. High-sensitivity C-reactive protein was the only biomarker that was positively correlated with carotid IMT in both groups. In the HIV-infected group, soluble vascular cell adhesion molecule-1 was positively correlated with all inflammatory cytokine levels. In multiple regression analysis, soluble vascular cell adhesion molecule-1, myeloperoxidase, and tumor necrosis factor-alpha levels were all associated with internal carotid artery IMT in the HIV-infected group, whereas age was associated with both common carotid artery and internal carotid artery IMT.. Enhanced endothelial activation, inflammation, and increased carotid IMT occur in HIV-infected patients despite antiretroviral therapy. Inflammatory markers are associated with endothelial activation, and both are associated with internal carotid artery IMT, supporting a potential role of inflammation in endothelial activation and cardiovascular disease in HIV infection.

Topics: Anti-HIV Agents; Antiretroviral Therapy, Highly Active; C-Reactive Protein; Cardiovascular Diseases; Carotid Arteries; Cross-Sectional Studies; Cytokines; HIV Infections; Humans; Peroxidase; Prospective Studies; Tunica Intima; Vascular Cell Adhesion Molecule-1

We evaluated whether myeloperoxidase (MPO) predicts future cardiovascular disease (CVD) events in asymptomatic adults and whether subclinical atherosclerosis may affect this relation.. Myeloperoxidase is a leukocyte-derived enzyme-generating reactive oxidant species that has been shown to predict risk of CVD in selected populations.. We studied 1,302 asymptomatic adults (mean age 59 years, 47% women) without known CVD who were followed for 3.8 years. We measured MPO by the use of immunoassay. Coronary artery calcium (CAC), a measure of subclinical atherosclerosis, was measured by computed tomography with the Agatston score categorized as none/minimal (0 to 9), mild (10 to 99), and moderate/significant (> or = 100). Cox regression, adjusted for age, sex, and other risk factors, examined the relation of CAC and/or MPO with incident CVD events.. Persons with MPO levels at or above compared with below the median (257 pM) were more likely (p < 0.05 to p < 0.001) to be women, have a higher body mass index, greater low-density lipoprotein cholesterol, greater systolic and diastolic blood pressure, and lower high-density lipoprotein cholesterol. Mean MPO levels increased according to CAC categories (p trend = 0.02). Incident CVD events were more likely in those at or above versus below the median MPO level (4.6% vs. 2.3%, p = 0.02), even after adjustment for age, sex, CAC, and risk factors (hazard ratio [HR]: 1.9, 95% confidence interval: 1.0 to 3.6, p = 0.04). Combining CAC and MPO categories, CVD incidence ranged from 0.6% in those with a CAC score of 0 to 9 to 7.1% (adjusted HR: 9.2, p < 0.001) in those with CAC scores of > or = 100 and MPO below the median and 14.0% (adjusted HR: 19.5, p < 0.0001) in those with CAC scores of > or = 100 and MPO at or above the median.. Our study suggests persons with both increased levels of both MPO and CAC are at an increased risk of CVD events. Imaging of subclinical atherosclerosis combined with assessment of biomarkers of plaque vulnerability may help improve CVD risk stratification.

Topics: Aged; Biomarkers; Calcinosis; Cardiovascular Diseases; Coronary Angiography; Coronary Artery Disease; Female; Humans; Immunoassay; Logistic Models; Male; Middle Aged; Odds Ratio; Peroxidase; Predictive Value of Tests; Proportional Hazards Models; Risk Assessment; Risk Factors; Severity of Illness Index; Tomography, X-Ray Computed; Up-Regulation

Topics: Biomarkers; Calcinosis; Cardiovascular Diseases; Coronary Angiography; Coronary Artery Disease; Humans; Immunoassay; Peroxidase; Predictive Value of Tests; Risk Assessment; Risk Factors; Severity of Illness Index; Tomography, X-Ray Computed; Up-Regulation

Myeloperoxidase catalyzes the formation of reactive oxygen metabolites in neutrophils and monocytes. Increased plasma myeloperoxidase concentrations are linked to coronary artery stenosis and may be useful for risk prediction following acute coronary syndromes. We studied the influence of the - 129 G>A and - 463 G>A myeloperoxidase gene promoter polymorphisms on myeloperoxidase concentrations and reactive oxygen metabolite production after neutrophil stimulation.. Neutrophils from 305 healthy blood donors were stimulated with N-Formyl-Met-Leu-Phe or phorbol-myristate-acetate. Plasma myeloperoxidase concentrations were quantified by enzyme immunoassay and reactive oxygen metabolites by flow cytometry. Genotyping was performed by PCR and restriction fragment length analysis.. The - 129 A allele was associated with lower myeloperoxidase concentrations in unstimulated blood (P< 0.05), but the variation among the genotypes was small. Plasma myeloperoxidase was unrelated to the - 463 G> A polymorphism. Baseline myeloperoxidase was associated with use of sex hormones in women, but not with sex, age, smoking habits or use of nonsteroid anti-inflammatory medication. The polymorphisms were not associated with the change from baseline in myeloperoxidase or reactive oxygen metabolites after neutrophil stimulation. Control experiments on myeloperoxidase function in cell lysates from 50 additional donors confirmed the results.. The - 129 A allele was associated with slightly lower myeloperoxidase plasma concentrations. The - 129 G>A and - 463 G>A polymorphisms did not affect myeloperoxidase degranulation or reactive oxygen metabolite production after neutrophil activation. It therefore seems unlikely that they are mechanistically related to the risk for atherosclerosis. Our findings may explain why associations between these polymorphisms and cardiovascular disease have been difficult to reproduce.

Topics: Cardiovascular Diseases; Cell Degranulation; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Gene Frequency; Genetic Predisposition to Disease; Humans; Male; N-Formylmethionine Leucyl-Phenylalanine; Neutrophil Activation; Neutrophils; Peroxidase; Phenotype; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Reactive Oxygen Species; Risk Assessment; Risk Factors; Tetradecanoylphorbol Acetate

To investigate, using a longitudinal design, whether biomarkers of cardiovascular risk change after a switch to an abacavir (ABC)-containing regimen in HIV-1-infected individuals already receiving combination antiretroviral therapy (ART).. Thirty-five HIV-1-infected individuals who switched ART to an ABC-containing regimen were identified. Twenty-two HIV-1-infected individuals who switched ART from and to a non-ABC-containing regimen served as controls. Plasma concentrations of soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble intercellular adhesion molecule 1 (sICAM-1), matrix metallopeptidase 9 (MMP9), myeloperoxidase (MPO) and high sensitivity C-reactive protein (hs-CRP) were measured in blood samples before the switch in ART, and 3 months and 12 months afterwards. Log10-transformed data were compared with paired t-tests.. Median MMP9 increased from 45.5 to 64.4 microg/mL after 3 months of ABC exposure (P = 0.011) and remained increased after 12 months (64.2 microg/mL; P = 0.013). MPO increased from median 8.8 to 10.4 microg/mL (P = 0.036) after 3 months of ABC exposure but was not increased after 12 months of exposure (9.1 microg/mL). hs-CRP increased from 3.3 to 4.2 microg/mL after 3 months (P = 0.031) but was not increased after 12 months of exposure (2.8 microg/mL). Neither sVCAM-1 nor sICAM-1 changed after the initiation of ABC. No changes were observed in the control group.. MMP9, MPO and hs-CRP all increased after a switch in ART to an ABC-containing regimen. This indicates increased cardiovascular risk in viral load-suppressed HIV-1-infected individuals switching to ABC and proposes a proinflammatory potential as the underlying pathogenetic mechanism.

Topics: Adult; Aged; Anti-Retroviral Agents; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Dideoxynucleosides; Drug Therapy, Combination; Female; HIV Infections; Humans; Intercellular Adhesion Molecule-1; Longitudinal Studies; Male; Matrix Metalloproteinase 9; Middle Aged; Peroxidase; Risk Factors; Vascular Cell Adhesion Molecule-1; Viral Load; Zidovudine

High incidence of cardiovascular disease (CVD) in chronic kidney disease (CKD) patients is a result of an interlaced relation between oxidative stress, endothelial dysfunction (ED) and inflammation. This study tries to investigate the development of these processes in CKD patients receiving conservative treatment or on hemodialysis (HD). We also examined the modulating effect of oral L-arginine in HD patients having CVD.. The study included 12 healthy volunteers and 63 renal patients divided into 15 renal impairment, 18 HD free of CVD, and 30 HD suffering from CVD (HD+CVD). Of the latter, 15 patients were given oral L-arginine (15 g/day, 5 g t.i.d.) for 1 month. Blood levels of asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), and homocysteine and myeloperoxidase activity (MPO) were estimated.. ADMA, MDA and homocysteine were significantly elevated in renal impairment group. HD and HD+CVD patients experienced higher levels, along with high MPO activity. Significant reduction by 21, 46, 11, and 26%, respectively, in the aforementioned parameters was observed in HD+CVD patients following L-arginine intake.. We recommend considering ADMA, MDA, homocysteine and MPO as potentially important cardiovascular risk factors in CKD patients, and focus the attention to the cardiovascular advantages of L-arginine in these patients.

Topics: Aged; Arginine; Cardiovascular Diseases; Case-Control Studies; Homocysteine; Humans; Kidney Failure, Chronic; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Peroxidase; Renal Dialysis; Risk Factors

Myeloperoxidase (MPO) is an enzyme derived of leukocytes that catalyze formation of numerous reactive oxidant species. Besides members of the innate host defense, evidences have been proving the contribution of these oxidants to tissue injury during inflammation. MPO participates in proatherogenic biological activities related to the evolution of cardiovascular disease, including initiation, propagation and acute complications of atherosclerotic process. Thereby, MPO and its inflammatory cascade represents an attractive target for prognostical investigation and therapeutics in atherosclerotic cardiovascular disease. In this review, we present the state of the art in the understanding of biological actions to clinical evidences of the relationship between MPO and coronary arterial disease. Several studies point to the independent effect of MPO levels in the evolution of disease and incidence of events in patients with acute coronary syndrome. However, the additional predictive value of MPO levels in the cardiovascular risk assessment, to incorporate it to the clinical practice as marker of plaque vulnerability, is still not consistent. Additional studies are necessary to confirm its role in the different forms of presentation of ischemic disease, besides the standardization of the assay, fundamental point for transition of this marker from research atmosphere to use in clinical routine: : from laboratory to clinical practice.

Topics: Acute Coronary Syndrome; Arteriosclerosis; Biomarkers; Cardiovascular Diseases; Coronary Artery Disease; Humans; Lipid Metabolism; Nitric Oxide; Peroxidase; Prognosis

Topics: Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal; Biomarkers; Blood Donors; Cardiovascular Diseases; Humans; Immunoassay; Peroxidase

This editorial refers to Myeloperoxidase, but not C-reactive protein, predicts cardiovascular risk in peripheral arterial disease by G. Brevetti et al., on page 224.

Topics: Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Humans; Peripheral Vascular Diseases; Peroxidase; Risk Assessment

Erectile dysfunction (ED) is a major vascular disorder. Atherosclerosis is closely related to lipoprotein metabolism and especially, oxidative modifications of low-density lipoproteins (LDLs), which are involved in early development of the atherosclerotic lesions. Current major questions include how LDLs are oxidised (OxLDL) in vivo. Myeloperoxidase (MPO) is an enzyme present in the azurophile granules of neutrophils and monocytes that can contribute to LDL oxidation in the presence of H(2)O(2). We have developed a new monoclonal antibody against LDL modified by MPO (Mox-LDL) and have used it on penile biopsies from patients operated on for penile implant.. Seven patients with vascular ED and one impotent patient after radical prostatectomy (RP) underwent biopsy of the cavernous body during penile implant procedures. An immunohistochemical study with a monoclonal antibody against Mox-LDL and an antibody against apoprotein B (ApoB), the protein moiety of LDL, to confirm the presence of LDL was performed.. The staining was positive for Mox-LDL and ApoB and was present between the endothelial cells of the sinusoid spaces and the smooth muscle cells in the seven patients with vascular ED. The patient with RP was negative for Mox-LDL.. Because it is known that modified LDL could decrease nitric oxide production, Mox-LDL could be one of the agents responsible for ED. Further studies are needed to confirm this hypothesis.

Topics: Aged; Apolipoproteins B; Cardiovascular Diseases; Erectile Dysfunction; Humans; Immunohistochemistry; Impotence, Vasculogenic; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Penis; Peroxidase

We examined the effect of cyclooxygenase (COX) inhibitors on dextran sulfate sodium (DSS)-induced ulcerative colitis in rats and investigated the role of COX isozymes in the pathogenesis of this model. Experimental colitis was induced by treatment with 2.5% DSS in drinking water for 6 days. Indomethacin (a nonselective COX inhibitor), SC-560 (a selective COX-1 inhibitor), or celecoxib (a selective COX-2 inhibitor) was given PO twice daily for 6 days, during the first 3 or last 3 days of the experimental period. Daily treatment with 2.5% DSS for 6 days caused damage to the colon, with a decrease in body weight gain and colon length as well as an increase of myeloperoxidase (MPO) activity. All COX inhibitors given for 6 days significantly worsened the severity of DSS-induced colonic damage with increased MPO activity. The aggravation was also observed by SC-560 given for the first 3 days or by celecoxib given for the last 3 days. The expression of COX-2 mRNA in the colon was upregulated on day 3 during DSS treatment, with significant increase of prostaglandin E(2) PGE(2) production. The PGE(2) content on day 3 during DSS treatment was inhibited by both indomethacin and SC-560, but not by celecoxib; on day 6 it was suppressed by both indomethacin and celecoxib, but not SC-560. These results suggest that endogenous prostaglandins (PGs) afford protection against colonic ulceration, yet the COX isozyme responsible for the production of PGs differs depending on the stage of ulceration; COX-1 in the early stage and COX-2 in the late stage.

Topics: Animals; Cardiovascular Diseases; Celecoxib; Colitis, Ulcerative; Colon; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Dextran Sulfate; Dinoprostone; Disease Models, Animal; Gene Expression; Indomethacin; Male; Peroxidase; Plasma Substitutes; Pyrazoles; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spectrophotometry; Sulfonamides; Treatment Outcome

To assess carotid intima media thickness (IMT) and cardiac biomarkers in HIV infected children on antiretroviral therapy (ART).. This was a single site, cross sectional, controlled observational study. We assessed carotid IMT, homocysteine, high-sensitivity C-reactive protein and myeloperoxidase levels in HIV infected children on stable ART for >or= 6 months. Carotid IMT was reported as internal carotid artery (ICA) and common carotid artery (CCA) thickness; left and right sides were measured separately. Groups were compared using appropriate two-sample tests.. Of the 62 subjects enrolled, 31 were HIV positive (50%), 66% were female, and 69% were African-American. Median CD4% was 32% and 26 patients (84%) had HIV-1 RNA< 400 copies/ml. Sixteen patients had been taking protease inhibitors for a median duration of 27 months. None had hypertension or smoked. HIV infected children had higher HOMA-IR, waist-to-hip ratio, cholesterol, triglycerides, myeloperoxidase and lower homocysteine levels. Left and right CCA IMT, and left and right ICA IMT were significantly higher in the HIV infected group. Significant predictors of carotid IMT measurements in uninfected controls were body mass index and homocysteine, but only the duration of ARV therapy was predictive of IMT in the HIV infected group.. Higher levels of carotid IMT and some cardiac markers were found in ART treated HIV infected children when compared to matched uninfected controls. These results suggest that HIV infected children receiving ART may be at increased risk of cardiovascular disease.

Topics: Adolescent; Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Biomarkers; Body Composition; C-Reactive Protein; Cardiovascular Diseases; Carotid Arteries; Carotid Artery, Common; Carotid Artery, Internal; Child; Child, Preschool; Cross-Sectional Studies; Drug Administration Schedule; Female; HIV Infections; Homocysteine; Humans; Lipids; Male; Peroxidase; Tunica Intima; Tunica Media; Ultrasonography

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Atherosclerosis; Biomarkers; Cardiology; Cardiovascular Diseases; CD40 Ligand; Cell Adhesion Molecules; Cytokines; Education, Medical, Continuing; Humans; Peroxidase

Topics: Animals; Apoptosis; Atherosclerosis; Carbamates; Cardiovascular Diseases; Cell Proliferation; Citrulline; Endothelial Cells; Humans; Inflammation; Lipoproteins, HDL; Lipoproteins, LDL; Lysine; Macrophages; Mice; Models, Biological; Muscle, Smooth; Oxidation-Reduction; Peroxidase; Scavenger Receptors, Class A; Smoking; Substrate Specificity; Thiocyanates

High-density lipoprotein (HDL) inhibits atherosclerosis by removing cholesterol from artery wall macrophages. Additionally, HDL is anti-inflammatory in animal studies, suggesting that this property might also be important for its cardioprotective effects. Recent studies in subjects with established cardiovascular disease (CVD) demonstrate that myeloperoxidase targets HDL for oxidation and blocks the lipoprotein's ability to remove excess cholesterol from cells, raising the possibility that the enzyme provides a specific mechanism for generating dysfunctional HDL in humans. Shotgun proteomic analysis of HDL identified multiple complement regulatory proteins, protease inhibitors, and acute-phase response proteins, supporting a central role for HDL in inflammation. Mass spectrometry and biochemical analyses demonstrated that HDL(3) from CVD subjects was selectively enriched in apolipoprotein E, suggesting that it carries a unique cargo of proteins in humans with clinically significant CVD. Thus, oxidative modifications to HDL and changes in its protein composition might be useful biomarkers-and perhaps mediators-of CVD.

Topics: Apolipoprotein A-I; Atherosclerosis; Cardiovascular Diseases; Humans; Lipoproteins, HDL; Macrophage Inflammatory Proteins; Oxidation-Reduction; Oxidative Stress; Peroxidase

Fabry disease results in a global vasculopathy leading to early-onset stroke and renal and cardiac failure. We found that random myeloperoxidase in serum and plasma was significantly elevated in 73 consecutive male patients with Fabry disease. Random serum myeloperoxidase level in men predicted the risk of a Fabry vasculopathy-related event in subsequent years. Long-term enzyme replacement therapy did not reduce myeloperoxidase level or eliminate the risk of vasculopathic events.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cardiovascular Diseases; Child; Fabry Disease; Female; Follow-Up Studies; Humans; Male; Middle Aged; Peroxidase; Predictive Value of Tests; Prospective Studies; Risk Factors

Topics: Aged; Biomarkers; Cardiovascular Diseases; Endothelium, Vascular; Female; Humans; Male; Middle Aged; Peroxidase; Predictive Value of Tests; Retrospective Studies

We investigated the effect of a therapeutic dose of raloxifene on the plasma levels of myeloperoxidase and F2alpha-isoprostanes, two markers of oxidative stress recently described as reliable indicators of coronary heart disease. Contrary to changes described in the literature for estrogens (E), raloxifene did not modify the levels of either myeloproxidase or F2alpha-isoprostanes after 3 or 6 months of treatment.

Topics: Antioxidants; Biomarkers; Cardiovascular Diseases; F2-Isoprostanes; Female; Humans; Middle Aged; Neutrophils; Oxidative Stress; Peroxidase; Postmenopause; Raloxifene Hydrochloride; Selective Estrogen Receptor Modulators

Asymmetric dimethylarginine (ADMA), myeloperoxidase (MPO) and paraoxonase 1 (PON1) are directly involved in the pathogenesis of atherosclerosis by modulation of oxidative stress and/or NO bioavailability. We aimed to assess whether endurance exercise which is known to be cardioprotective could beneficially affect these novel risk markers. Thirty-two subjects (31-68 yrs, 56% males) with elevated cardiovascular risk including ten patients with coronary artery disease volunteered for a supervised 12-week endurance training (196 +/- 15 min/week). Their fitness evaluated by 2 km test runs improved significantly after training (pre: 17.3 +/- 0.8 vs. post: 15.7 +/- 0.9 min, p < 0.001). ADMA (pre: 0.94 +/- 0.03 vs. post: 0.75 +/- 0.04 micromol l(-1)) and MPO (pre: 296.8 +/- 22.2 vs.post: 185.7 +/- 19.5 ng ml(-1)) serum levels decreased significantly by 17.6 +/- 4.6% and 28.5 +/- 7.5%, respectively, after training (both p < 0.001). Their down-regulation was inversely correlated (ADMA: r = -0.609, p < 0.001, MPO: r = -0.437, p = 0.014) with the up-regulation of plasma cGMP levels (Cyclic-guanosine 3',5'-monophosphate; pre: 1.6 +/- 0.12 vs. post: 2.21 +/- 0.2 micromol ml(-1), p = 0.001) reflecting NO production. PON1 activity towards phenylacetate was not significantly influenced by training (pre: 133 +/- 6 vs. post: 130 +/- 5 micromol ml(-1) min(-1), p = 0.375). In a matched inactive control group (n = 16) ADMA, MPO, cGMP levels and PON1 activity did not change over time. ADMA, MPO and cGMP changes were significantly different between participants and controls (all p < 0.05). Regular endurance exercise was successful in reducing the circulating levels of two promising cardiovascular risk markers, ADMA and MPO, in persons prone to cardiac events. These changes may result in numerous antiatherosclerotic effects such as improvement of NO bioavailability, reduction of oxidative stress and lipid peroxidation.

Topics: Adult; Aged; Arginine; Cardiovascular Diseases; Cyclic GMP; Exercise; Female; Humans; Male; Middle Aged; Peroxidase; Risk Factors

Topics: Angina Pectoris; Biomarkers; Cardiovascular Diseases; Chest Pain; Humans; Peroxidase; Polymorphism, Genetic; Prognosis; Promoter Regions, Genetic; Risk Assessment

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cardiovascular Diseases; Coronary Disease; Female; Humans; Male; Middle Aged; Multivariate Analysis; Peroxidase; Polymorphism, Genetic; Promoter Regions, Genetic; Proportional Hazards Models; Prospective Studies

In recent studies we demonstrated that systemic levels of protein-bound nitrotyrosine (NO(2)Tyr) and myeloperoxidase (MPO), a protein that catalyzes generation of nitrating oxidants, serve as independent predictors of atherosclerotic risk, burden, and incident cardiac events. We now show both that apolipoprotein A-I (apoA-I), the primary protein constituent of HDL, is a selective target for MPO-catalyzed nitration and chlorination in vivo and that MPO-catalyzed oxidation of HDL and apoA-I results in selective inhibition in ABCA1-dependent cholesterol efflux from macrophages. Dramatic selective enrichment in NO(2)Tyr and chlorotyrosine (ClTyr) content within apoA-I recovered from serum and human atherosclerotic lesions is noted, and analysis of serum from sequential subjects demonstrates that the NO(2)Tyr and ClTyr contents of apoA-I are markedly higher in individuals with cardiovascular disease (CVD). Analysis of circulating HDL further reveals that higher NO(2)Tyr and ClTyr contents of the lipoprotein are each significantly associated with diminished ABCA1-dependent cholesterol efflux capacity of the lipoprotein. MPO as a likely mechanism for oxidative modification of apoA-I in vivo is apparently facilitated by MPO binding to apoA-I, as revealed by cross-immunoprecipitation studies in plasma, recovery of MPO within HDL-like particles isolated from human atheroma, and identification of a probable contact site between the apoA-I moiety of HDL and MPO. To our knowledge, the present results provide the first direct evidence for apoA-I as a selective target for MPO-catalyzed oxidative modification in human atheroma. They also suggest a potential mechanism for MPO-dependent generation of a proatherogenic dysfunctional form of HDL in vivo.

Topics: Aged; Animals; Aorta; Apolipoprotein A-I; Arteriosclerosis; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Blotting, Western; Cardiovascular Diseases; Catalysis; Cell Line; Cholesterol; Cohort Studies; Female; Femoral Artery; Humans; Lipoproteins, HDL; Macrophages; Male; Mice; Middle Aged; Nitro Compounds; Oxidation-Reduction; Peroxidase; Tyrosine

In vitro and animal studies demonstrate that myeloperoxidase catalytically consumes nitric oxide as a substrate, limiting its bioavailability and function. We therefore hypothesized that circulating levels of myeloperoxidase would predict risk of endothelial dysfunction in human subjects.. Serum myeloperoxidase was measured by enzyme-linked immunoassay, and brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were determined by ultrasound in a hospital-based population of 298 subjects participating in an ongoing study of the clinical correlates of endothelial dysfunction (age, 51+/-16; 61% men, 51% with cardiovascular disease). A strong inverse relation between brachial artery flow-mediated dilation and increasing quartile of serum myeloperoxidase level was observed (11.0+/-6.0%, 9.4+/-5.3%, 8.6+/-5.8%, and 6.4+/-4.5% for quartiles 1 through 4, respectively; P<0.001 for trend). Using the median as a cut point to define endothelial dysfunction, increasing quartile of myeloperoxidase predicted endothelial dysfunction after adjustment for classic cardiovascular disease risk factors, C-reactive protein levels, prevalence of cardiovascular disease, and ongoing treatment with cardiovascular medications (OR, 6.4; 95% CI, 2.6 to 16; P=0.001 for highest versus lowest quartile).. Serum myeloperoxidase levels serve as a strong and independent predictor of endothelial dysfunction in human subjects. Myeloperoxidase-mediated endothelial dysfunction may be an important mechanistic link between oxidation, inflammation, and cardiovascular disease.

Topics: Adult; Aged; Biomarkers; Brachial Artery; C-Reactive Protein; Cardiovascular Diseases; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Lipids; Male; Middle Aged; Nitroglycerin; Oxidative Stress; Peroxidase; Predictive Value of Tests; Risk; Ultrasonography; Vasodilation

Topics: Apolipoprotein A-I; Cardiovascular Diseases; Cholesterol, LDL; Humans; Inflammation; Macrophages; Peroxidase

Topics: Animals; Apolipoprotein A-I; Biomarkers; Cardiovascular Diseases; Cholesterol; Humans; Lipoproteins, HDL; Magnetic Resonance Imaging; Oxidation-Reduction; Peroxidase; Risk Factors; Tyrosine

Topics: Animals; Cardiovascular Diseases; Electrocardiography; Heart; In Vitro Techniques; Leukotrienes; Lipoxygenase Inhibitors; Male; Myocardium; Peroxidase; Quinolines; Rabbits; Random Allocation

A group of 100 totally or subtotally myeloperoxidase (MPO)-deficient individuals was compared to a reference population of 118 probands selected at random. Data for a protective effect of the deficiency against cardiovascular damage are presented. On the other hand, a significantly higher occurrence of severe infections and chronic inflammatory processes was noted among the deficient patients. An increased incidence of cancer among the MPO-deficient individuals was not demonstrated.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Arthritis; Cardiovascular Diseases; Case-Control Studies; Chi-Square Distribution; Child; Child, Preschool; Chronic Disease; Female; Humans; Infections; Male; Middle Aged; Myocardial Infarction; Neoplasms; Peroxidase; Risk Factors

The oxidation of low density lipoprotein (LDL) has been suggested as a key event in atherogenesis. Paradoxically, exercise, which imposes an oxidative stress, is an important deterrent of cardiovascular disease. In study 1 the oxidizability of LDL was enhanced in exercisers compared with sedentary controls. The lag time of isolated LDL subjected to copper-induced in vitro oxidation was significantly shortened in the exercisers compared with sedentary subjects. This increased sensitivity was not due to a decreased presence of vitamin E. Instead, these findings suggested that the LDL of exercisers may contain increased amounts of preformed lipid peroxides, which account for the increased oxidizability. In study 2, a group x sex ANOVA revealed that male exercisers had a significantly longer mean lag time than male sedentary subjects and that females had similar mean lag times regardless of exercise group. This remained the case when statistical adjustment was made for age, body mass index, blood lipid levels, LDL, and plasma alpha-tocopherol levels. Study 1 exercisers had been in training for a shorter time (< 1 year) than study 2 exercisers (> 2 years). These findings suggest that truly "chronic" exercise (aerobic intensity over several months) decreases the susceptibility of a male exerciser's LDL to undergo oxidation. Conversely, regular aerobic stress during an overall shorter time span creates a more oxidative environment in the body, thus increasing the susceptibility of LDL to undergo oxidation. The oxidative stress of aerobic exercise does not appear to adversely affect the oxidizability of LDL in women.

Topics: Adolescent; Adult; Cardiovascular Diseases; Copper; Exercise; Female; Humans; Lipid Peroxides; Lipoproteins, LDL; Male; Oxidative Stress; Oxygen Consumption; Peroxidase; Thiobarbituric Acid Reactive Substances; Vitamin E

Platelet-activating factor (PAF) is a glycerophospholipid known for its unusual potent vasoactive and proinflammatory activities. The present study examined whether PAF might serve as a priming factor in endotoxin-induced tumor necrosis factor-alpha (TNF alpha) synthesis, cardiovascular shock, and lung injury in anesthetized rats. Intravenous infusion of PAF (1 pmol/kg/min for 60 minutes, n = 5) alone or endotoxin (0.1 micrograms/kg i.v. bolus, n = 5) failed to alter blood pressure, serum TNF alpha and thromboxane B2, platelet and leukocyte count, and hematocrit, nor was lung histology, myeloperoxidase activity, and water content changed. In contrast, the combined administration of PAF and endotoxin markedly elevated serum TNF alpha (1,359 +/- 362 pg/ml, n = 5, p less than 0.01) and thromboxane B2 (43 +/- 5 pg/100 microliters, n = 8, p less than 0.01) along with hypotension, hemoconcentration, leukopenia, and thrombocytopenia. Most notably, the combined regimen caused neutrophil aggregation, adhesion, and accumulation into the lung parenchyma along with platelet-fibrin deposits in postcapillary venules, pulmonary edema, and increased lung myeloperoxidase activity. The role of PAF in this process was confirmed by 1) the prevention of the priming effect by pretreatment with the PAF antagonist BN 50739 (n = 5), and 2) the failure of lyso-PAF, the cardinal nonactive PAF-metabolite, to prime for endotoxin-induced production of TNF alpha (n = 4). These data suggest that PAF could serve as a key mediator in priming for endotoxin-induced tissue injury, especially the typical pulmonary pathophysiology of adult respiratory distress syndrome, a severe pathological outcome of septic shock, burns, and multiple organ injury.

Topics: Animals; Body Water; Cardiovascular Diseases; Drug Synergism; Endotoxins; Escherichia coli; Hemodynamics; Lipopolysaccharides; Lung; Lung Diseases; Male; Microscopy, Electron, Scanning; Organ Size; Peroxidase; Platelet Activating Factor; Rats; Rats, Inbred Strains; Thromboxane B2; Tumor Necrosis Factor-alpha