This Article Abstract Full Text (PDF) All Versions of this Article: 108/4/426    most recent 01.CIR.0000080895.05158.8Bv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shishehbor, M. H. Articles by Hazen, S. L. Search for Related Content PubMed PubMed Citation Articles by Shishehbor, M. H. Articles by Hazen, S. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Antioxidants Cholesterol Statins Hazardous Substances DB ATORVASTATIN HEPTANOIC ACID L-TYROSINE PYRROLE Related Collections Primary prevention Secondary prevention Pathophysiology Risk Factors Other diagnostic testing Brain Circulation and Metabolism Chronic ischemic heart disease Lipid and lipoprotein metabolism Oxidant stress Endothelium/vascular type/nitric oxide

(Circulation. 2003;108:426.)
© 2003 American Heart Association, Inc.

Clinical Investigation and Reports

Statins Promote Potent Systemic Antioxidant Effects Through Specific Inflammatory Pathways

Mehdi H. Shishehbor, DO^*; Marie-Luise Brennan, PhD^*; Ronnier J. Aviles, MD; Xiaoming Fu, MS; Marc S. Penn, MD, PhD; Dennis L. Sprecher, MD; Stanley L. Hazen, MD, PhD

From the Departments of Cell Biology, Cardiovascular Medicine, and the Center for Cardiovascular Diagnostics and Prevention, Cleveland Clinic Foundation, Cleveland, Ohio.

Correspondence to Stanley L. Hazen, MD, PhD, Cleveland Clinic Foundation, 9500 Euclid Ave, NC10, Cleveland, OH 44195. E-mail hazens{at}ccf.org

Received March 19, 2003; revision received May 6, 2003; accepted May 7, 2003.

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Background— The pleiotropic actions of hydroxymethylglutaryl CoA reductase inhibitors (statins) include antiinflammatory and antioxidant actions. We recently reported that statins induce reductions in plasma protein levels of nitrotyrosine (NO₂Tyr), a modification generated by nitric oxide–derived oxidants. Whether alternative oxidative pathways are suppressed in vivo after statin administration has not yet been reported.

Methods and Results— As an extension of our prior study, hypercholesterolemic subjects with no known coronary artery disease were evaluated at baseline and after 12 weeks of atorvastatin therapy (10 mg/d). Plasma levels of protein-bound chlorotyrosine, NO₂Tyr, dityrosine, and orthotyrosine, specific molecular fingerprints for distinct oxidative pathways upregulated in atheroma, were determined by mass spectrometry. In parallel, alterations in lipoproteins and C-reactive protein were determined. Statin therapy caused significant reductions in chlorotyrosine, NO₂Tyr, and dityrosine (30%, 25%, and 32%, respectively; P<0.02 each) that were similar in magnitude to reductions in total cholesterol and apolipoprotein B-100 (25% and 29%, P<0.001 each). Nonsignificant decreases in orthotyrosine and C-reactive protein levels were observed (9% and 11%, respectively; P>0.10 each). Statin-induced reductions in oxidation markers were independent of decreases in lipids and lipoproteins.

Conclusions— Statins promote potent systemic antioxidant effects through suppression of distinct oxidation pathways. The major pathways inhibited include formation of myeloperoxidase-derived and nitric oxide–derived oxidants, species implicated in atherogenesis. The present results suggest potential mechanisms that may contribute to the beneficial actions of statins. They also have important implications for monitoring the antiinflammatory and antioxidant actions of these agents.

Key Words: statins • antioxidants • hypercholesterolemia • atherosclerosis • inflammation

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
Hydroxymethylglutaryl CoA reductase inhibitors (statins) promote reductions in plasma levels of LDL cholesterol, a primary risk factor in coronary artery disease. Numerous primary and secondary prevention trials confirm clinical benefits with this class of agents.^1,2 The mechanisms involved have largely been attributed to the ability of these agents to inhibit cholesterol synthesis, leading to upregulation of hepatic LDL receptors and corresponding reductions in circulating levels of LDL particles. However, a growing body of evidence suggests that some of the clinical benefits of statin therapy may be attributed to mechanisms independent of their cholesterol-lowering effects.^3–5 These so-called pleiotropic effects are believed to include antiinflammatory and antioxidant actions. Statin-induced reductions in acute-phase reactant proteins such as C-reactive protein (CRP) provide strong evidence for an overall antiinflammatory effect of these agents.^6,7 We recently reported that statin therapy lowers systemic levels of protein-bound nitrotyrosine (NO₂Tyr), a marker for oxidant stress mediated via pathways involving nitric oxide (·NO)-derived oxidants.⁸ A systematic approach to both quantify and define the specific oxidative pathways suppressed in vivo after statin administration has not yet been reported.

Enhanced oxidant stress occurs within the artery wall of atherosclerotic vessels.^9–11 Multiple distinct oxidation products are enriched within human atherosclerotic plaques, as well as LDL recovered from diseased versus normal human aorta.^12,13 However, the role of oxidation in the pathogenesis of coronary artery disease has recently been questioned because of the failures of multiple prospective interventional trials with antioxidant supplements.^9,14,15 However, none of the major antioxidant trials to date concomitantly measured systemic markers of oxidant stress to ensure an effect on the process targeted for intervention (ie, oxidation). This is particularly relevant because many oxidation pathways known to occur within human atheroma (Figure) are not effectively inhibited by tocopherol (vitamin E),^10,15–17 the major antioxidant supplement in these trials. Moreover, under certain conditions, pro-oxidant rather than antioxidant actions for species like tocopherol and ascorbate (vitamin C) are observed.^18,19 Thus, it has been argued that the failures of antioxidant trials should not be perceived as an indictment of the "oxidation hypothesis" of atherosclerosis.^9,10,15,20 Indeed, recent studies confirm no significant reductions in systemic levels of lipid oxidation products in subjects taking up to 2000 IU/d of tocopherol.¹⁴

View larger version (28K): [in this window] [in a new window]   Scheme of enzymatic pathways used by leukocytes and vascular wall cells for generating reactive oxidants and diffusible radical species. Each of the oxidation pathways and reactive oxidant species noted has the potential to initiate lipid peroxidation. eNOS indicates endothelial NO synthase; H2O2, hydrogen peroxide; HOCl, hypochlorous acid; iNOS, inducible NO synthase; L-Arg, L-arginine, M2+, redox-active metal ion; m-Tyr, meta-tyrosine; MPO, myeloperoxidase; ·NO2, nitrogen dioxide; NO2-, nitrite; NOX, NAD(P)H oxidase of vascular endothelial cells; O2, molecular oxygen; ·O2-, superoxide anion; ·OH, hydroxyl radical; ONOO-, peroxynitrite; Pr(M2+), protein-bound redox-active metal ion; and ·Tyr, tyrosyl radical.

Much of what is known about the pathways responsible for oxidative injury within atherosclerotic vessels has been gained by detection of stable structurally informative oxidation products that convey information regarding the pathways responsible for their generation.^10,12,21 The Figure is a model of major pathways for oxidant generation implicated in the pathogenesis of atherosclerosis and stable informative protein oxidation products produced by these pathways. A molecular marker for protein oxidative damage by ·NO-derived oxidants (NO₂Tyr), myeloperoxidase-generated chlorinating species (chlorotyrosine [ClTyr]), or oxidative crosslinks (dityrosine [diTyr]) and, to a lesser extent, formation of hydroxyl radical-like oxidants (ortho-tyrosine [o-Tyr]) are enriched within human atheroma and LDL recovered from atherosclerotic laden versus normal aorta.^{10,12,21–24} These pathways have been shown to participate in oxidative conversion of LDL into an atherogenic particle,^25,26 initiation of lipid peroxidation,²⁷ consumption of ·NO potentially leading to endothelial dysfunction,²⁸ and activation of matrix metalloprotease and alternative protease cascades, potentially leading to development of the vulnerable plaque.^29–31 Remarkably, tocopherol is relatively ineffective in blocking these oxidation pathways.^10,15–17

The ability of statins to inhibit isoprenylation of key proteins involved in oxidant/antioxidant-generating machinery within the vessel wall suggests that these agents may promote systemic antioxidant effects. Cell culture studies demonstrate that statin therapy suppresses superoxide formation and enhances ·NO generation by vascular endothelial cells via inhibition of isoprenylation of Rac and Rho.^32,33 Rac is a component of the NAD(P)H oxidase complex of both leukocytes and vascular cells. Statin-induced inhibition of Rac isoprenylation impairs its translocation to membranes, leading to suppression in superoxide formation from cultured cells.³² Rho is a small GTPase involved in cell signaling. Inhibition in Rho isoprenylation in endothelial cells has been shown to result in enhanced ·NO production, an effect likely to produce overall antioxidant action.³³

The present study was designed to test the hypothesis that statins promote systemic antioxidant effects via multiple distinct oxidation pathways implicated in the atherosclerotic process. It is based on the recognition that superoxide formation from leukocyte and vascular cell NAD(P)H oxidases is a critical proximal step in oxidant formation by pathways implicated in generation of reactive oxidant species within the artery wall (Figure). Using mass spectrometry–based methods for the quantification of plasma protein levels of distinct molecular markers, we now both quantify and define specific oxidative pathways suppressed in vivo after statin administration to hypercholesterolemic subjects.

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Study Protocol
Samples used were from subjects enrolled in a recently described prospective, open-label interventional trial with atovastatin.⁸ Consecutive patients (n=35) meeting entry criteria were recruited from the Preventive Cardiology Clinic at the Cleveland Clinic Foundation. Patients 21 years of age and older without clinical evidence of coronary artery disease and with LDL cholesterol (LDL-C) levels 130 mg/dL or greater, despite at least 8 weeks of therapeutic lifestyle interventions, were eligible to participate in the study. Patients received treatment with atorvastatin at a dose of 10 mg orally per day. Fasting morning plasma samples were collected before initiation of therapy (baseline) and after 12 weeks of therapy. Patients with active liver disease or renal insufficiency defined as a serum creatinine level 1.8 mg/dL were excluded. Patients were followed through clinic visits at weeks 2, 4, 6, 8, and 12. All patients gave written informed consent, and the Institutional Review Board at the Cleveland Clinic Foundation approved the study protocol.

Blood Samples
Fasting blood was collected into EDTA tubes. Plasma was recovered after centrifugation at 3500 rpm for 10 minutes at 4°C. Aliquots were stored under conditions to minimize artificial oxidation by addition of antioxidant cocktail (100 µmol/L butylated hydroxytoluene and 100 µmol/L diethylenetriaminepentaacetic acid) overlaid with argon, stored at -80°C until analysis. Standard methods were used to measure lipid levels and high-sensitivity CRP.

Nitrotyrosine, Dityrosine, Chlorotyrosine, and ortho-Tyrosine Analyses
Protein-bound NO₂Tyr was determined by stable isotope dilution liquid chromatography–tandem mass spectrometry on an ion trap mass spectrometer (LCQ Deca, ThermoFinigann), as previously described.^8,34 Protein-bound ClTyr, diTyr, and o-Tyr analyses were performed by gas chromatography/mass spectrometry after derivatization of amino acids to their n-propyl per heptafluorylbutyryl derivatives using a Finnigan Voyager GC/MS in the negative ion chemical ionization mode, as described.³⁴ Synthetic [¹³C₆]-labeled standards (in cases of NO₂Tyr, ClTyr, and o-Tyr) or [¹³C₁₂]-labeled standards (in case of diTyr) were added to plasma protein pellets and used as internal standards for quantification of natural abundance analytes. Simultaneously, universal labeled precursor amino acids [¹³C₉,¹⁵N₁]tyrosine (for NO₂Tyr, ClTyr, and diTyr) or [¹³C₉,¹⁵N₁]phenylalanine (for o-Tyr) were added to plasma protein pellets.³⁴ Proteins were hydrolyzed under argon atmosphere in methane sulfonic acid, and then samples were passed over mini solid-phase C18 extraction columns (Supelclean LC-C18-SPE Minicolumn; 3 mL; Supelco, Inc) before mass spectrometry analysis.³⁴ Results are normalized to the content of the precursor amino acid tyrosine (for NO₂Tyr, ClTyr, or diTyr) or phenylalanine (for o-Tyr), which were monitored within the same injection of each oxidized amino acid. Intrapreparative formation of nitro[¹³C₉,¹⁵N]tyrosine, chloro[¹³C₉,¹⁵N]tyrosine, di[¹³C₁₈,¹⁵N₂]tyrosine, and ortho[¹³C₉,¹⁵N] tyrosine was routinely monitored and was negligible (ie, <5% of the level of the natural abundance product observed) under the conditions used.

Statistical Analysis
Data are presented as mean±SD, and significance level was set at P<0.05. Wilcoxon rank-sum test was used to analyze the differences between NO₂Tyr, diTyr, and CRP at baseline and 12 weeks, because they were not normally distributed. The differences between baseline and 12 weeks for lipid parameters, ClTyr, and o-Tyr levels were performed using paired Student’s t test. Spearman-rank correlation was used to assess the association between baseline NO₂Tyr, diTyr, ClTyr, o-Tyr, CRP, and lipid parameters. Multiple regression analyses were performed to determine factors associated with changes in NO₂Tyr, diTyr, and ClTyr. Statistical analyses were performed using SPSS version 11.0.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Baseline characteristics of the patients are shown in Table 1. Follow-up data were available for all 35 patients at 12 weeks. In general, other than hypercholesterolemia, the patients were a healthy cohort without any known coronary artery disease or diabetes. Absolute and percentage change of baseline and 12-week measurements of total cholesterol (TC), LDL-C, HDL-C, triglycerides, CRP, ClTyr, diTyr, NO₂Tyr, and o-Tyr are shown in Table 2. As expected, treatment with atorvastatin led to a significant reduction in TC, LDL-C, and apolipoprotein (apo) B-100 levels (25%, 39%, and 29%, respectively). Atorvastatin caused comparable significant reductions in the levels of oxidation products produced by myeloperoxidase and ·NO-derived oxidants (reductions in ClTyr, diTyr, and NO₂Tyr of 30%, 32%, and 25%, respectively; Table 2). In contrast, the reduction in o-Tyr and CRP were modest (9% and 11%, respectively) and failed to reach statistical significance (Table 2).

View this table: [in this window] [in a new window]   TABLE 1. Baseline Characteristics

View this table: [in this window] [in a new window]   TABLE 2. Lipid and Inflammatory Markers at Baseline and After Atorvastatin Therapy

Additional analyses were performed to determine if either baseline levels or observed changes in oxidation markers (NO₂Tyr, diTyr, ClTyr, and o-Tyr) were associated with baseline levels or observed changes in either lipid parameters or CRP. Baseline NO₂Tyr levels, a specific molecular fingerprint for protein modification by ·NO-derived oxidants, were correlated with fasting triglyceride levels (r=-0.36, P=0.033; Table 3). No other significant correlations were found between baseline levels of oxidation markers and either lipid parameters or CRP (Table 3). Significant correlations were noted between statin-induced changes in ClTyr, a specific molecular fingerprint of myeloperoxidase-catalyzed oxidation, and changes in both NO₂Tyr and HDL-C levels (r=0.37, P=0.028 and r=0.36, P=0.036, respectively; Table 4). Changes in o-Tyr, a product of protein oxidation by metal catalyzed hydroxyl radical-like species, was associated with changes in fasting triglycerides (r=-0.38, P=0.026; Table 4). In multiple regression analyses that included changes in lipid parameters and oxidation markers, the only significant correlation noted was between changes in ClTyr and NO₂Tyr, (P=0.002).

View this table: [in this window] [in a new window]   TABLE 3. Baseline Spearman Correlations*

View this table: [in this window] [in a new window]   TABLE 4. Spearman Correlations for Changes in Oxidative Markers and Lipid Parameters

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
The present studies demonstrate significant reductions in levels of specific molecular footprints of distinct oxidative pathways after atorvastatin therapy. Marked reductions in systemic markers specific for protein oxidative modification by myeloperoxidase-derived and ·NO-derived oxidants were observed that were largely independent of statin-induced changes in lipid parameters and CRP. Furthermore, the magnitude of reductions in oxidation markers on statin therapy was comparable in size to the reductions observed in fasting TC and apo B100. The mechanisms underlying the overall systemic antioxidant effects are likely class effects for these agents (ie, inhibition in isoprenylation). It is thus tempting to speculate that statin trials may in fact represent not only lipid-lowering interventions but also antioxidant trials. Additional studies are needed to determine if the systemic antioxidant effects promoted by atorvastatin therapy are similarly seen with other agents in this class. Furthermore, it will be of interest to determine if the clinical benefits observed with statins are independently predicted by reductions in specific oxidation markers, particularly because reductions in oxidation products were independent of statin-induced alterations in TC, LDL-C, and apo B100, lipid and lipoprotein parameters presently used in monitoring efficacy and dosing of statins.

The present studies not only suggest a reappraisal of the oxidation hypothesis of atherosclerosis but also invite the overhaul of the design and monitoring of future antioxidant intervention trials. Common sense dictates that to claim antioxidant effect, one needs to demonstrate reductions in oxidation products. Incorporation of this approach in future antioxidant studies is required. The oxidation markers chosen for the present study provide mechanistic information with regards to the pathways responsible for their formation. Furthermore, unlike lipid oxidation products, which are readily generated during sample storage and archiving, many of the molecular markers monitored are stable and not readily formed during storage. These characteristics make them potentially useful and practical tools for both defining oxidative pathways operative in cardiovascular syndromes and for assessing the efficacy of antioxidant and antiinflammatory interventions. They also are required for the meaningful analysis of archival specimens for correlation with clinical outcomes, because significant measures are rarely taken during sample collection and storage to prevent or minimize lipid oxidation. The sophisticated and labor-intensive methods required for accurate determination of oxidative markers, which typically involve mass spectrometry, have delayed their widespread use in clinical studies. However, these very same methods illustrate the necessity of using such techniques, because simultaneous monitoring of assay methods to ensure no significant artifactual formation of the oxidation markers during sample handling and processing for analyses has proven to be critical in method development and accurate quantitative assessment of these markers.

Oxidative consumption of ·NO, such as through interaction with superoxide, both suppresses ·NO bioavailability and produces a potent nitrating oxidant, peroxynitrite (ONOO^-; Figure). We recently reported that systemic NO₂Tyr levels serve as an independent predictor of cardiovascular risk and burden and are modulated by statin therapy.⁸ The present studies confirm and extend these observations by showing that multiple alternative oxidation pathways, particularly those catalyzed by myeloperoxidase, demonstrate comparable reductions. Myeloperoxidase is a leukocyte-derived heme protein that is enriched in human atheroma.^30,35 Normally playing a role in innate host defenses, myeloperoxidase-generated reactive nitrogen species, chlorinating oxidants, and tyrosyl radical have each been linked to potential pathogenic mechanisms, including conversion of LDL into a high-uptake form,^10,25,26 activation of matrix metalloproteases and other protease cascades,^29–31 and initiation of lipid peroxidation in vivo.^27,36 Autopsy studies of subjects with sudden death reveal intense immunostaining for myeloperoxidase within culprit lesions that have undergone fissuring or plaque rupture.³⁰ Myeloperoxidase has also recently been shown to serve as an independent predictor of atherosclerotic risk in subjects undergoing coronary angiography.³⁷ Myeloperoxidase deficiency is associated with decreased frequency of cardiovascular events,³⁸ and functional polymorphisms in the myeloperoxidase gene that lead to decreased enzyme expression confer cardioprotection.³⁹ The present studies thus provide additional support, albeit indirect, for the hypothesis that myeloperoxidase-generated oxidants are involved in the pathogenesis of cardiovascular disease.

Another intriguing finding of the present studies was the significant association between statin-elicited reductions in levels of protein-bound NO₂Tyr and ClTyr in plasma (r=0.37, P=0.028; Table 4). Such a finding is consistent with myeloperoxidase playing a significant role in formation of ·NO-derived oxidants in humans (Figure). A role for myeloperoxidase in the generation of ·NO-derived oxidants is supported by studies using leukocytes isolated from subjects with myeloperoxidase deficiency, animal models of inflammation using myeloperoxidase knockout mice,^27,34 and the discovery that myeloperoxidase and other members of the mammalian heme peroxidase superfamily catalytically consume ·NO as a physiological substrate.²⁸

In summary, by using molecular footprints of specific oxidative pathways, we have shown that statins promote potent systemic antioxidant effects independent of changes seen in lipid, lipoprotein, and CRP levels. Furthermore, the amino acid oxidation products ClTyr, diTyr, and NO₂Tyr demonstrate significant reductions even when presented as a product to precursor ratio, indicating a true decrease in oxidant stress after atorvastatin therapy. These data support the hypothesis that statins induce potent systemic antiinflammatory and antioxidant effects and have important implications for the monitoring of nonlipid-related, or so-called pleiotropic actions, of this important class of drug.

	Acknowledgments

 
Supported by National Institutes of Health grants HL70621, HL62526, and HL61878 (S.L. Hazen) and GCRC grant number M01 RR18390-1. M.H. Shishehbor is supported by a Crile Fellowship Award, and R.J. Aviles is supported by an American Heart Association Fellowship Award. Mass spectrometry analyses were performed at the Cleveland Clinic Foundation Mass Spectrometry Core Facility within the Center for Cardiovascular Diagnostics and Prevention.

	Footnotes

 
Dr Hazen is named as coinventor on pending patents filed by the Cleveland Clinic Foundation that relate to use of biomarkers for inflammatory and cardiovascular diseases.

*These authors contributed equally to this work.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet. 1994; 344: 1383–1389.[CrossRef][Medline] [Order article via Infotrieve]

2. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet. 2002; 360: 7–22.[CrossRef][Medline] [Order article via Infotrieve]

3. Munford RS. Statins and the acute-phase response. N Engl J Med. 2001; 344: 2016–2018.[Free Full Text]

4. Blake GJ, Ridker PM. Are statins anti-inflammatory? Curr Control Trials Cardiovasc Med. 2000; 1: 161–165.[Medline] [Order article via Infotrieve]

5. Takemoto M, Liao JK. Pleiotropic effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors. Arterioscler Thromb Vasc Biol. 2001; 21: 1712–1719.[Abstract/Free Full Text]

6. Ridker PM, Rifai N, Clearfield M, et al. Measurement of C-reactive protein for the targeting of statin therapy in the primary prevention of acute coronary events. N Engl J Med. 2001; 344: 1959–1965.[Abstract/Free Full Text]

7. Ridker PM, Rifai N, Pfeffer MA, et al. Long-term effects of pravastatin on plasma concentration of C-reactive protein: the Cholesterol and Recurrent Events (CARE) Investigators. Circulation. 1999; 100: 230–235.[Abstract/Free Full Text]

8. Shishehbor MH, Aviles RJ, Brennan ML, et al. Association of nitrotyrosine levels with cardiovascular disease and modulation by statin therapy. JAMA. 2003; 289: 1675–1680.[Abstract/Free Full Text]

9. Steinberg D, Witztum JL. Is the oxidative modification hypothesis relevant to human atherosclerosis? Do the antioxidant trials conducted to date refute the hypothesis? Circulation. 2002; 105: 2107–2111.[Free Full Text]

10. Podrez EA, Abu-Soud HM, Hazen SL. Myeloperoxidase-generated oxidants and atherosclerosis. Free Radic Biol Med. 2000; 28: 1717–1725.[CrossRef][Medline] [Order article via Infotrieve]

11. Chisolm GM, Steinberg D. The oxidative modification hypothesis of atherogenesis: an overview. Free Radic Biol Med. 2000; 28: 1815–1826.[CrossRef][Medline] [Order article via Infotrieve]

12. Davies MJ, Fu S, Wang H, et al. Stable markers of oxidant damage to proteins and their application in the study of human disease. Free Radic Biol Med. 1999; 27: 1151–1163.[CrossRef][Medline] [Order article via Infotrieve]

13. Heinecke JW. Mechanisms of oxidative damage by myeloperoxidase in atherosclerosis and other inflammatory disorders. J Lab Clin Med. 1999; 133: 321–325.[CrossRef][Medline] [Order article via Infotrieve]

14. Meagher EA, Barry OP, Lawson JA, et al. Effects of vitamin E on lipid peroxidation in healthy persons. JAMA. 2001; 285: 1178–1182.[Abstract/Free Full Text]

15. Heinecke JW. Is the emperor wearing clothes? Clinical trials of vitamin E and the LDL oxidation hypothesis. Arterioscler Thromb Vasc Biol. 2001; 21: 1261–1264.[Abstract/Free Full Text]

16. Savenkova ML, Mueller DM, Heinecke JW. Tyrosyl radical generated by myeloperoxidase is a physiological catalyst for the initiation of lipid peroxidation in low density lipoprotein. J Biol Chem. 1994; 269: 20394–20400.[Abstract/Free Full Text]

17. Hazell LJ, Stocker R. -tocopherol does not inhibit hypochlorite-induced oxidation of apolipoprotein B-100 of low-density lipoprotein. FEBS Lett. 1997; 414: 541–544.[CrossRef][Medline] [Order article via Infotrieve]

18. Upston JM, Terentis AC, Stocker R. Tocopherol-mediated peroxidation of lipoproteins: implications for vitamin E as a potential antiatherogenic supplement. FASEB J. 1999; 13: 977–994.[Abstract/Free Full Text]

19. Podmore ID, Griffiths HR, Herbert KE, et al. Vitamin C exhibits pro-oxidant properties. Nature. 1998; 392: 559–602.[CrossRef][Medline] [Order article via Infotrieve]

20. Cai H, Harrison DG. Endothelial dysfunction in cardiovascular diseases: the role of oxidant stress. Circ Res. 2000; 87: 840–844.[Abstract/Free Full Text]

21. Heinecke JW. Oxidized amino acids: culprits in human atherosclerosis and indicators of oxidative stress. Free Radic Biol Med. 2002; 32: 1090–1101.[CrossRef][Medline] [Order article via Infotrieve]

22. Leeuwenburgh C, Rasmussen JE, Hsu FF, et al. Mass spectrometric quantification of markers for protein oxidation by tyrosyl radical, copper, and hydroxyl radical in low density lipoprotein isolated from human atherosclerotic plaques. J Biol Chem. 1997; 272: 3520–3526.[Abstract/Free Full Text]

23. Hazen SL, Heinecke JW. 3-Chlorotyrosine, a specific marker of myeloperoxidase-catalyzed oxidation, is markedly elevated in low density lipoprotein isolated from human atherosclerotic intima. J Clin Invest. 1997; 99: 2075–2081.[Medline] [Order article via Infotrieve]

24. Leeuwenburgh C, Hardy MM, Hazen SL, et al. Reactive nitrogen intermediates promote low density lipoprotein oxidation in human atherosclerotic intima. J Biol Chem. 1997; 272: 1433–1436.[Abstract/Free Full Text]

25. Podrez EA, Schmitt D, Hoff HF, et al. Myeloperoxidase-generated reactive nitrogen species convert LDL into an atherogenic form in vitro. J Clin Invest. 1999; 103: 1547–1560.[Medline] [Order article via Infotrieve]

26. Hazell LJ, van den Berg JJ, Stocker R. Oxidation of low-density lipoprotein by hypochlorite causes aggregation that is mediated by modification of lysine residues rather than lipid oxidation. Biochem J. 1994; 302 (pt 1): 297–304.[Medline] [Order article via Infotrieve]

27. Zhang R, Shen Z, Nauseef WM, et al. Defects in leukocyte-mediated initiation of lipid peroxidation in plasma as studied in myeloperoxidase-deficient subjects: systematic identification of multiple endogenous diffusible substrates for myeloperoxidase in plasma. Blood. 2002; 99: 1802–1810.[Abstract/Free Full Text]

28. Abu-Soud HM, Hazen SL. Nitric oxide is a physiological substrate for mammalian peroxidases. J Biol Chem. 2000; 275: 37524–37532.[Abstract/Free Full Text]

29. Fu X, Kassim SY, Parks WC, et al. Hypochlorous acid oxygenates the cysteine switch domain of pro-matrilysin (MMP-7): a mechanism for matrix metalloproteinase activation and atherosclerotic plaque rupture by myeloperoxidase. J Biol Chem. 2001; 276: 41279–41287.[Abstract/Free Full Text]

30. Sugiyama S, Okada Y, Sukhova GK, et al. Macrophage myeloperoxidase regulation by granulocyte macrophage colony-stimulating factor in human atherosclerosis and implications in acute coronary syndromes. Am J Pathol. 2001; 158: 879–891.[Abstract/Free Full Text]

31. Desrochers PE, Mookhtiar K, Van Wart HE, et al. Proteolytic inactivation of alpha 1-proteinase inhibitor and alpha 1-antichymotrypsin by oxidatively activated human neutrophil metalloproteinases. J Biol Chem. 1992; 267: 5005–5012.[Abstract/Free Full Text]

32. Wassmann S, Laufs U, Muller K, et al. Cellular antioxidant effects of atorvastatin in vitro and in vivo. Arterioscler Thromb Vasc Biol. 2002; 22: 300–305.[Abstract/Free Full Text]

33. Laufs U, La Fata V, Plutzky J, et al. Upregulation of endothelial nitric oxide synthase by HMG CoA reductase inhibitors. Circulation. 1998; 97: 1129–1135.[Abstract/Free Full Text]

34. Brennan ML, Wu W, Fu X, et al. A tale of two controversies: defining both the role of peroxidases in nitrotyrosine formation in vivo using eosinophil peroxidase and myeloperoxidase-deficient mice, and the nature of peroxidase-generated reactive nitrogen species. J Biol Chem. 2002; 277: 17415–17427.[Abstract/Free Full Text]

35. Daugherty A, Dunn JL, Rateri DL, et al. Myeloperoxidase, a catalyst for lipoprotein oxidation, is expressed in human atherosclerotic lesions. J Clin Invest. 1994; 94: 437–444.[Medline] [Order article via Infotrieve]

36. Zhang R, Brennan ML, Shen Z, et al. Myeloperoxidase functions as a major enzymatic catalyst for initiation of lipid peroxidation at sites of inflammation. J Biol Chem. 2002; 277: 46116–46122.[Abstract/Free Full Text]

37. Zhang R, Brennan ML, Fu X, et al. Association between myeloperoxidase levels and risk of coronary artery disease. JAMA. 2001; 286: 2136–2142.[Abstract/Free Full Text]

38. Kutter D, Devaquet P, Vanderstocken G, et al. Consequences of total and subtotal myeloperoxidase deficiency: risk or benefit? Acta Haematol. 2000; 104: 10–15.[CrossRef][Medline] [Order article via Infotrieve]

39. Nikpoor B, Turecki G, Fournier C, et al. A functional myeloperoxidase polymorphic variant is associated with coronary artery disease in French-Canadians. Am Heart J. 2001; 142: 336–339.[CrossRef][Medline] [Order article via Infotrieve]

This article has been cited by other articles:

				A. Anselmi, G. Possati, and M. Gaudino Postoperative inflammatory reaction and atrial fibrillation: simple correlation or causation? Ann. Thorac. Surg., July 1, 2009; 88(1): 326 - 333. [Abstract] [Full Text] [PDF]

				K. L. Bruner-Tran, K. G. Osteen, and A. J. Duleba Simvastatin Protects against the Development of Endometriosis in a Nude Mouse Model J. Clin. Endocrinol. Metab., July 1, 2009; 94(7): 2489 - 2494. [Abstract] [Full Text] [PDF]

				M. J. Thomson, M. P. Frenneaux, and J. C. Kaski Antioxidant treatment for heart failure: friend or foe? QJM, May 1, 2009; 102(5): 305 - 310. [Abstract] [Full Text] [PDF]

				S. J. Nicholls and S. L. Hazen Myeloperoxidase, modified lipoproteins, and atherogenesis J. Lipid Res., April 1, 2009; 50(Supplement): S346 - S351. [Abstract] [Full Text] [PDF]

				D. Kaireviciute, A. Aidietis, and G. Y.H. Lip Atrial fibrillation following cardiac surgery: clinical features and preventative strategies Eur. Heart J., February 2, 2009; 30(4): 410 - 425. [Abstract] [Full Text] [PDF]

				M. H. SHISHEHBOR and S. L. HAZEN JUPITER to Earth: A statin helps people with normal LDL-C and high hs-CRP, but what does it mean? Cleveland Clinic Journal of Medicine, January 1, 2009; 76(1): 37 - 44. [Abstract] [Full Text] [PDF]

				E. S. Spatz, M. E. Canavan, and M. M. Desai From Here to JUPITER: Identifying New Patients for Statin Therapy Using Data From the 1999-2004 National Health and Nutrition Examination Survey Circ Cardiovasc Qual Outcomes, January 1, 2009; 2(1): 41 - 48. [Abstract] [Full Text] [PDF]

				A. Kourliouros, A. De Souza, N. Roberts, A. Marciniak, A. Tsiouris, O. Valencia, J. Camm, and M. Jahangiri Dose-Related Effect of Statins on Atrial Fibrillation After Cardiac Surgery Ann. Thorac. Surg., May 1, 2008; 85(5): 1515 - 1520. [Abstract] [Full Text] [PDF]

				L. Guasti, F. Marino, M. Cosentino, R. C. Maio, E. Rasini, M. Ferrari, L. Castiglioni, C. Klersy, G. Gaudio, A. M. Grandi, et al. Prolonged statin-associated reduction in neutrophil reactive oxygen species and angiotensin II type 1 receptor expression: 1-year follow-up Eur. Heart J., May 1, 2008; 29(9): 1118 - 1126. [Abstract] [Full Text] [PDF]

				B. Ky, A. Burke, S. Tsimikas, M. L. Wolfe, M. G. Tadesse, P. O. Szapary, J. L. Witztum, G. A. FitzGerald, and D. J. Rader The Influence of Pravastatin and Atorvastatin on Markers of Oxidative Stress in Hypercholesterolemic Humans J. Am. Coll. Cardiol., April 29, 2008; 51(17): 1653 - 1662. [Abstract] [Full Text] [PDF]

				M. F. Walter, R. F. Jacob, R. E. Bjork, B. Jeffers, J. Buch, Y. Mizuno, R. P. Mason, and on behalf of the PREVENT Investigators Circulating Lipid Hydroperoxides Predict Cardiovascular Events in Patients With Stable Coronary Artery Disease: The PREVENT Study J. Am. Coll. Cardiol., March 25, 2008; 51(12): 1196 - 1202. [Abstract] [Full Text] [PDF]

				M. Nahrendorf, D. Sosnovik, J. W. Chen, P. Panizzi, J.-L. Figueiredo, E. Aikawa, P. Libby, F. K. Swirski, and R. Weissleder Activatable Magnetic Resonance Imaging Agent Reports Myeloperoxidase Activity in Healing Infarcts and Noninvasively Detects the Antiinflammatory Effects of Atorvastatin on Ischemia-Reperfusion Injury Circulation, March 4, 2008; 117(9): 1153 - 1160. [Abstract] [Full Text] [PDF]

				R. Cangemi, L. Loffredo, R. Carnevale, L. Perri, M. P. Patrizi, V. Sanguigni, P. Pignatelli, and F. Violi Early decrease of oxidative stress by atorvastatin in hypercholesterolaemic patients: effect on circulating vitamin E Eur. Heart J., January 1, 2008; 29(1): 54 - 62. [Abstract] [Full Text] [PDF]

				J. I. Keddissi, W. G. Younis, E. A. Chbeir, N. N. Daher, T. A. Dernaika, and G. T. Kinasewitz The Use of Statins and Lung Function in Current and Former Smokers Chest, December 1, 2007; 132(6): 1764 - 1771. [Abstract] [Full Text] [PDF]

				A. Radaelli, C. Loardi, M. Cazzaniga, G. Balestri, C. DeCarlini, M. G. Cerrito, E. N. Cusa, L. Guerra, S. Garducci, D. Santo, et al. Inflammatory Activation During Coronary Artery Surgery and Its Dose-Dependent Modulation by Statin/ACE-Inhibitor Combination Arterioscler. Thromb. Vasc. Biol., December 1, 2007; 27(12): 2750 - 2755. [Abstract] [Full Text] [PDF]

				G. Peluffo and R. Radi Biochemistry of protein tyrosine nitration in cardiovascular pathology Cardiovasc Res, July 15, 2007; 75(2): 291 - 302. [Abstract] [Full Text] [PDF]

				M.S. Kostapanos, E.N. Liberopoulos, J.A. Goudevenos, D.P. Mikhailidis, and M.S. Elisaf Do statins have an antiarrhythmic activity? Cardiovasc Res, July 1, 2007; 75(1): 10 - 20. [Abstract] [Full Text] [PDF]

				M. Sugita, H. Sugita, and M. Kaneki Farnesyltransferase Inhibitor, Manumycin A, Prevents Atherosclerosis Development and Reduces Oxidative Stress in Apolipoprotein E-Deficient Mice Arterioscler. Thromb. Vasc. Biol., June 1, 2007; 27(6): 1390 - 1395. [Abstract] [Full Text] [PDF]

				S. Kinlay Low-Density Lipoprotein-Dependent and -Independent Effects of Cholesterol-Lowering Therapies on C-Reactive Protein: A Meta-Analysis J. Am. Coll. Cardiol., May 22, 2007; 49(20): 2003 - 2009. [Abstract] [Full Text] [PDF]

				I. C. Van Gelder Rhythm control for atrial fibrillation: Non-channel antiarrhythmic drugs are en vogue Cardiovasc Res, April 1, 2007; 74(1): 8 - 10. [Full Text] [PDF]

				A. Shiroshita-Takeshita, B. J.J.M. Brundel, B. Burstein, T.-K. Leung, H. Mitamura, S. Ogawa, and S. Nattel Effects of simvastatin on the development of the atrial fibrillation substrate in dogs with congestive heart failure Cardiovasc Res, April 1, 2007; 74(1): 75 - 84. [Abstract] [Full Text] [PDF]

				P. Van Antwerpen, K. Z. Boudjeltia, M. Vaes, S. Babar, P. Madhoun, N. Moguilevsky, M. Vanhaeverbeek, J. Neve, and J. Ducobu The pleiotropic effect of statins in haemodialysis patients is not the consequence of an inhibition of LDL oxidation by myeloperoxidase Nephrol. Dial. Transplant., September 1, 2006; 21(9): 2672 - 2674. [Full Text] [PDF]

				C. D. Collard, S. C. Body, S. K. Shernan, S. Wang, D. T. Mangano, and Multicenter Study of Perioperative Ischemia (MCSPI Preoperative statin therapy is associated with reduced cardiac mortality after coronary artery bypass graft surgery. J. Thorac. Cardiovasc. Surg., August 1, 2006; 132(2): 392 - 400. [Abstract] [Full Text] [PDF]

				E Hothersall, C McSharry, and N C Thomson Potential therapeutic role for statins in respiratory disease. Thorax, August 1, 2006; 61(8): 729 - 734. [Abstract] [Full Text] [PDF]

				B. E. K. Klein, R. Klein, K. E. Lee, and L. M. Grady Statin Use and Incident Nuclear Cataract JAMA, June 21, 2006; 295(23): 2752 - 2758. [Abstract] [Full Text] [PDF]

				T. Nawrot, A. Nemmar, and B. Nemery Update in environmental and occupational medicine 2005. Am. J. Respir. Crit. Care Med., May 1, 2006; 173(9): 948 - 952. [Full Text] [PDF]

				S. Tsimikas, J. T. Willerson, and P. M. Ridker C-reactive protein and other emerging blood biomarkers to optimize risk stratification of vulnerable patients. J. Am. Coll. Cardiol., April 18, 2006; 47(8 Suppl): C19 - C31. [Abstract] [Full Text] [PDF]

				R. P. Mason, M. F. Walter, C. A. Day, and R. F. Jacob Active Metabolite of Atorvastatin Inhibits Membrane Cholesterol Domain Formation by an Antioxidant Mechanism J. Biol. Chem., April 7, 2006; 281(14): 9337 - 9345. [Abstract] [Full Text] [PDF]

				I. Dalle-Donne, R. Rossi, R. Colombo, D. Giustarini, and A. Milzani Biomarkers of Oxidative Damage in Human Disease Clin. Chem., April 1, 2006; 52(4): 601 - 623. [Abstract] [Full Text] [PDF]

				P. Stenvinkel, E. Rodriguez-Ayala, Z. A. Massy, A. R. Qureshi, P. Barany, B. Fellstrom, O. Heimburger, B. Lindholm, and A. Alvestrand Statin Treatment and Diabetes Affect Myeloperoxidase Activity in Maintenance Hemodialysis Patients Clin. J. Am. Soc. Nephrol., March 1, 2006; 1(2): 281 - 287. [Abstract] [Full Text] [PDF]

				B. Erdos, J. A. Snipes, C. D. Tulbert, P. Katakam, A. W. Miller, and D. W. Busija Rosuvastatin improves cerebrovascular function in Zucker obese rats by inhibiting NAD(P)H oxidase-dependent superoxide production Am J Physiol Heart Circ Physiol, March 1, 2006; 290(3): H1264 - H1270. [Abstract] [Full Text] [PDF]

				O Wazni, D O Martin, N F Marrouche, M Shaaraoui, M K Chung, S Almahameed, R A Schweikert, W I Saliba, and A Natale C reactive protein concentration and recurrence of atrial fibrillation after electrical cardioversion Heart, October 1, 2005; 91(10): 1303 - 1305. [Abstract] [Full Text] [PDF]

				J. Pleiner, G. Schaller, F. Mittermayer, S. Zorn, C. Marsik, S. Polterauer, S. Kapiotis, and M. Wolzt Simvastatin Prevents Vascular Hyporeactivity During Inflammation Circulation, November 23, 2004; 110(21): 3349 - 3354. [Abstract] [Full Text] [PDF]

				M. F. Walter, R. F. Jacob, B. Jeffers, M. M. Ghadanfar, G. M. Preston, J. Buch, and R. P. Mason Serum levels of thiobarbituric acid reactive substances predict cardiovascular events in patients with stable coronary artery disease: A longitudinal analysis of the PREVENT study J. Am. Coll. Cardiol., November 16, 2004; 44(10): 1996 - 2002. [Abstract] [Full Text] [PDF]

				I. Spyridopoulos, J. Haendeler, C. Urbich, T. H. Brummendorf, H. Oh, M. D. Schneider, A. M. Zeiher, and S. Dimmeler Statins Enhance Migratory Capacity by Upregulation of the Telomere Repeat-Binding Factor TRF2 in Endothelial Progenitor Cells Circulation, November 9, 2004; 110(19): 3136 - 3142. [Abstract] [Full Text] [PDF]

				A. Shiroshita-Takeshita, G. Schram, J. Lavoie, and S. Nattel Effect of Simvastatin and Antioxidant Vitamins on Atrial Fibrillation Promotion by Atrial-Tachycardia Remodeling in Dogs Circulation, October 19, 2004; 110(16): 2313 - 2319. [Abstract] [Full Text] [PDF]

				W. Pan, T. Pintar, J. Anton, V.-V. Lee, W. K. Vaughn, and C. D. Collard Statins Are Associated With a Reduced Incidence of Perioperative Mortality After Coronary Artery Bypass Graft Surgery Circulation, September 14, 2004; 110(11_suppl_1): II-45 - II-49. [Abstract] [Full Text] [PDF]

				D. Vishnevetsky, V. A Kiyanista, and P. J Gandhi CD40 Ligand: A Novel Target in the Fight Against Cardiovascular Disease Ann. Pharmacother., September 1, 2004; 38(9): 1500 - 1508. [Abstract] [Full Text] [PDF]

				P. M Ridker, N. J. Brown, D. E. Vaughan, D. G. Harrison, and J. L. Mehta Established and Emerging Plasma Biomarkers in the Prediction of First Atherothrombotic Events Circulation, June 29, 2004; 109(25_suppl_1): IV-6 - IV-19. [Full Text] [PDF]

				A. A. Mangoni Diastolic and Pulse Pressure: The Old and the New? Hypertension, March 1, 2004; 43(3): 531 - 532. [Full Text] [PDF]

				E. POLIAKOV, M.-L. BRENNAN, J. MACPHERSON, R. ZHANG, W. SHA, L. NARINE, R. G. SALOMON, and S. L. HAZEN Isolevuglandins, a novel class of isoprostenoid derivatives, function as integrated sensors of oxidant stress and are generated by myeloperoxidase in vivo FASEB J, December 1, 2003; 17(15): 2209 - 2220. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) All Versions of this Article: 108/4/426    most recent 01.CIR.0000080895.05158.8Bv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shishehbor, M. H. Articles by Hazen, S. L. Search for Related Content PubMed PubMed Citation Articles by Shishehbor, M. H. Articles by Hazen, S. L. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Antioxidants Cholesterol Statins Hazardous Substances DB ATORVASTATIN HEPTANOIC ACID L-TYROSINE PYRROLE Related Collections Primary prevention Secondary prevention Pathophysiology Risk Factors Other diagnostic testing Brain Circulation and Metabolism Chronic ischemic heart disease Lipid and lipoprotein metabolism Oxidant stress Endothelium/vascular type/nitric oxide