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Bäumer AT, Krüger CA, Falkenberg J, Freyhaus HT, Rösen R, Fink K, Rosenkranz S. The NAD(P)H Oxidase Inhibitor Apocynin Improves Endothelial NO/Superoxide Balance and Lowers Effectively Blood Pressure in Spontaneously Hypertensive Rats: Comparison to Calcium Channel Blockade. Clin Exp Hypertens 2009; 29:287-99. [PMID: 17653964 DOI: 10.1080/10641960701500398] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The vascular NAD(P)H oxidase contributes to endothelial dysfunction and high blood pressure in the spontaneously hypertensive rat by enhancing superoxide production. We investigated the effects of apocynin, a NAD(P)H oxidase inhibitor, on blood pressure and vascular radical and nitric oxide formation in SHR and compared its effects to the calcium channel blocker nifedipine. Apocynin (over four weeks) lowered systolic blood pressure significantly and as effectively as nifedipine. Both apocynin and nifedipine significantly reduced superoxide production. In parallel, vascular nitric oxide production and ecNOS activity was significantly increased by apocynin treatment. Therefore, apocynin may be an effective antihypertensive drug in essential hypertension.
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Affiliation(s)
- Anselm T Bäumer
- Klinik III für Innere Medizin, Universität zu Köln, Köln, Germany.
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52
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Wu J, Hecker JG, Chiamvimonvat N. Antioxidant enzyme gene transfer for ischemic diseases. Adv Drug Deliv Rev 2009; 61:351-63. [PMID: 19233238 DOI: 10.1016/j.addr.2009.01.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 01/28/2009] [Indexed: 02/07/2023]
Abstract
The balance of redox is pivotal for normal function and integrity of tissues. Ischemic insults occur as results of a variety of conditions, leading to an accumulation of reactive oxygen species (ROS) and an imbalanced redox status in the tissues. The oxidant stress may activate signaling mechanisms provoking more toxic events, and eventually cause tissue damage. Therefore, treatments with antioxidants, free radical scavengers and their mimetics, as well as gene transfer approaches to overexpress antioxidant genes represent potential therapeutic options to correct the redox imbalance. Among them, antioxidant gene transfer may enhance the production of antioxidant scavengers, and has been employed to experimentally prevent or treat ischemic injury in cardiovascular, pulmonary, hepatic, intestinal, central nervous or other systems in animal models. With improvements in vector systems and delivery approaches, innovative antioxidant gene therapy has conferred better outcomes for myocardial infarction, reduced restenosis after coronary angioplasty, improved the quality and function of liver grafts, as well as outcome of intestinal and cerebral ischemic attacks. However, it is crucial to be mindful that like other therapeutic armentarium, the efficacy of antioxidant gene transfer requires extensive preclinical investigation before it can be used in patients, and that it may have unanticipated short- or long-term adverse effects. Thus, it is critical to balance between the therapeutic benefits and potential risks, to develop disease-specific antioxidant gene transfer strategies, to deliver the therapy with an optimal time window and in a safe manner. This review attempts to provide the rationale, the most effective approaches and the potential hurdles of available antioxidant gene transfer approaches for ischemic injury in various organs, as well as the possible directions of future preclinical and clinical investigations of this highly promising therapeutic modality.
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Suda T, Kamimura K, Kubota T, Tamura Y, Igarashi M, Kawai H, Aoyagi Y, Liu D. Progress toward liver-based gene therapy. Hepatol Res 2009; 39:325-40. [PMID: 19207594 DOI: 10.1111/j.1872-034x.2008.00479.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The liver is involved in the synthesis of serum proteins, regulation of metabolism and maintenance of homeostasis and provides a variety of opportunities for gene therapy. The enriched vasculature and blood circulation, fenestrated endothelium, abundant receptors on the plasma membranes of the liver cells, and effective transcription and translation machineries in the hepatocytes are some unique features that have been explored for delivery, and functional analysis, of genetic sequences in the liver. Both viral and non-viral methods have been developed for effective gene delivery and liver-based gene therapy. This review describes the fundamentals of gene delivery, and the preclinical and clinical progress that has been made toward gene therapy using the liver as a target.
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Affiliation(s)
- Takeshi Suda
- Division of Gastroenterology and Hepatology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Niigata, Japan
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Frey RS, Ushio-Fukai M, Malik AB. NADPH oxidase-dependent signaling in endothelial cells: role in physiology and pathophysiology. Antioxid Redox Signal 2009; 11:791-810. [PMID: 18783313 PMCID: PMC2790033 DOI: 10.1089/ars.2008.2220] [Citation(s) in RCA: 314] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) including superoxide (O(2)(.-)) and hydrogen peroxide (H(2)O(2)) are produced endogenously in response to cytokines, growth factors; G-protein coupled receptors, and shear stress in endothelial cells (ECs). ROS function as signaling molecules to mediate various biological responses such as gene expression, cell proliferation, migration, angiogenesis, apoptosis, and senescence in ECs. Signal transduction activated by ROS, "oxidant signaling," has received intense investigation. Excess amount of ROS contribute to various pathophysiologies, including endothelial dysfunction, atherosclerosis, hypertension, diabetes, and acute respiratory distress syndrome (ARDS). The major source of ROS in EC is a NADPH oxidase. The prototype phagaocytic NADPH oxidase is composed of membrane-bound gp91phox and p22hox, as well as cytosolic subunits such as p47(phox), p67(phox) and small GTPase Rac. In ECs, in addition to all the components of phagocytic NADPH oxidases, homologues of gp91(phox) (Nox2) including Nox1, Nox4, and Nox5 are expressed. The aim of this review is to provide an overview of the emerging area of ROS derived from NADPH oxidase and oxidant signaling in ECs linked to physiological and pathophysiological functions. Understanding these mechanisms may provide insight into the NADPH oxidase and oxidant signaling components as potential therapeutic targets.
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Affiliation(s)
- Randall S Frey
- Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois 60612, USA.
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55
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Intravenous administration of mesenchymal stem cells genetically modified with extracellular superoxide dismutase improves survival in irradiated mice. Blood 2009; 113:1201-3. [PMID: 19179476 DOI: 10.1182/blood-2008-07-170936] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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56
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Abstract
Paul Vanhoutte is one of the fathers of vascular biology. Among his great contributions, he demonstrated that endothelium modulates vasomotor response to vasoactive products (including serotonin) that are released when platelets aggregate in an artery. He found in arteries ex vivo that when endothelium is dysfunctional, in atherosclerosis or hypertension, normal relaxation to aggregation of platelets is impaired and vessels may contract. He proposed that this mechanism may predispose to vasospasm. The results of our experiments in vivo indicate that atherosclerosis greatly potentiates vasoconstrictor responses to serotonin in the limb, brain, and eye of monkeys. We proposed that transient ischemic attacks may be mediated by platelet-induced vasospasm. We observed endothelial dysfunction in atherosclerotic monkeys, with improvement of endothelial function when hypercholesterolemia was corrected. Recently, we studied the aortic valve, which has unique endothelium, in hypercholesterolemic mice to examine the pathophysiology of aortic valvular stenosis. Oxidative stress is increased in stenotic valves, and severe aortic stenosis develops in about one third of old, hypercholesterolemic mice. In stenotic aortic valves from humans, there is increased oxidative stress near calcified regions of the valves. Oxidative stress may trigger expression of pro-calcific genes in the aortic valve. Finally, we have used gene transfer of extracellular superoxide dismutase (ecSOD) to study endothelial effects of oxidative stress. Gene transfer of normal ecSOD improves endothelial dysfunction in several disease states, but gene transfer of ecSOD(R213G), a gene variant of ecSOD that is common in humans, fails to improve endothelial function. Gene transfer approaches may be useful to study mechanisms by which gene variants predispose to endothelial dysfunction and vascular disease.
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57
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Abstract
Oxygen radicals, and other reactive oxygen species, may play an important role in the pathophysiology of atherosclerosis, stroke, and other cardiovascular diseases. Mechanisms that account for oxidative stress in different cardiovascular diseases are diverse; for example, increases in activity of NAD(P)H oxidase, "uncoupling" of nitric oxide synthase, and maladaptive changes in expression of antioxidants can all contribute to increases in oxidative stress. Very different patterns of pro-and antioxidant mechanisms that contribute to increases in oxygen radicals in atherosclerotic plaques, hemorrhagic strokes, and aortic valve stenosis have been observed. A disappointment, in relation to the hypothesis that oxygen radicals contribute to cardiovascular risk, is that many studies indicate that antioxidant vitamins fail to reduce the risk of cardiovascular disease. Better understanding of mechanisms that lead to increases in oxidative stress in different cardiovascular diseases may lead to more effective antioxidant prevention or treatment of diseases.
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Affiliation(s)
- Donald D Heistad
- Departments of Internal Medicine, University of Iowa Carver College of Medicine, 52242-1081, USA.
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59
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Nambiar S, Viswanathan S, Zachariah B, Hanumanthappa N, Magadi SG. Oxidative stress in prehypertension: rationale for antioxidant clinical trials. Angiology 2008; 60:221-34. [PMID: 18796443 DOI: 10.1177/0003319708319781] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Prehypertension has been recently described as an independent category of blood pressure. Mounting evidence suggests that blood pressure in the prehypertensive range is associated with an increased risk of developing hypertension and cardiovascular disease. Several reports have assigned a critical role for oxidative stress in these disease processes. This review focuses on the clinical and experimental studies done in prehypertension and hypertension within the context of oxidative stress. This article also provides insights into why diverse therapeutic interventions, which have in common the ability to reduce oxidative stress, can impede or delay the onset of hypertension in prehypertension subjects.
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Affiliation(s)
- Selvaraj Nambiar
- Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605 006, India
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60
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Qin Z, Gongora MC, Ozumi K, Itoh S, Akram K, Ushio-Fukai M, Harrison DG, Fukai T. Role of Menkes ATPase in angiotensin II-induced hypertension: a key modulator for extracellular superoxide dismutase function. Hypertension 2008; 52:945-51. [PMID: 18768397 DOI: 10.1161/hypertensionaha.108.116467] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The extracellular superoxide dismutase (SOD3), a secretory copper-containing enzyme, regulates angiotensin II (Ang II)-induced hypertension by modulating levels of extracellular superoxide anion. The present study was designed to determine the role of the copper transporter Menkes ATPase (MNK) in Ang II-induced SOD3 activity and hypertension in vivo. Here we show that chronic Ang II infusion enhanced systolic blood pressure and vascular superoxide anion production in MNK mutant (MNK(mut)) mice as compared with those in wild-type mice, which are associated with impaired acetylcholine-induced endothelium-dependent vasorelaxation in MNK(mut) mice. These effects in MNK(mut) mice are rescued by infusion of the SOD mimetic Tempol. By contrast, norepinephrine-induced hypertension, which is not associated with an increase in vascular superoxide anion production, is not affected in MNK(mut) mice. Mechanistically, basal and Ang II infusion-induced increase in vascular SOD3-specific activity is significantly inhibited in MNK(mut) mice. Coimmunoprecipitation analysis reveals that Ang II stimulation promotes association of MNK with SOD3 in cultured vascular smooth muscle cell and in mouse aortas, which may contribute to SOD3-specific activity by increasing copper delivery to SOD3 through MNK. In summary, MNK plays an important role in modulating Ang II-induced hypertension and endothelial function by regulating SOD3 activity and vascular superoxide anion production and becomes a potential therapeutic target for oxidant stress-dependent cardiovascular diseases.
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Affiliation(s)
- Zhenyu Qin
- Department of Medicine, Division of Cardiology, Emory University, School of Medicine, Atlanta, GA, USA
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61
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Schlüter T, Steinbach AC, Steffen A, Rettig R, Grisk O. Apocynin-induced vasodilation involves Rho kinase inhibition but not NADPH oxidase inhibition. Cardiovasc Res 2008; 80:271-9. [PMID: 18596059 DOI: 10.1093/cvr/cvn185] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
AIMS The present study was designed to test the hypothesis that NADPH oxidase inhibition with apocynin would lower blood pressure and improve endothelial function in spontaneously hypertensive rats (SHRs). Although apocyin effectively dilated arterial segments in vitro, it failed to lower blood pressure or improve endothelial function. Further experiments were performed in normotensive rats and in NADPH oxidase subunit knock-out mice to test if apocynin-induced vasodilation depends on NADPH oxidase inhibition at all. METHODS AND RESULTS SHRs were treated with apocynin orally or i.v. Arterial pressure was recorded directly. Rat and mouse arterial function was investigated in vitro by small vessel wire myography. NADPH oxidase activity was measured in human granulocytes and in rat vascular preparations. Rho kinase activity was determined by Western blot analysis. Apocynin did not reduce arterial pressure acutely in SHR when given at 50, 100, or 150 mg kg(-1) day(-1) orally over 1-week intervals or when given i.v. Apocynin potently inhibited granulocyte NADPH oxidase but not vascular NADPH-oxidase-dependent oxygen radical formation unless exogenous peroxidase was added to vascular preparations. Apocynin dilated rat intrarenal and coronary arteries independently of pharmacological interventions that reduce vascular superoxide radical abundance and actions. Aortic rings from p47phox(-/-) mice were more sensitive to apocynin-induced dilation than wild-type aortic rings. Rho kinase inhibition reduced or prevented the inhibitory effect of apocynin on agonist-induced vasoconstriction and apocynin inhibited the phosphorylation of Rho kinase substrates. CONCLUSION Apocynin per se does not inhibit vascular NADPH-oxidase-dependent superoxide formation. Its in vitro vasodilator actions are not due to NADPH oxidase inhibition but may be explained at least in part by inhibition of Rho kinase activity. The discrepancy between apocynin-induced vasodilation in vitro and the failure of apocynin to lower arterial pressure in SHR suggests opposing effects on arterial pressure-regulating systems in vivo. Its use as a pharmacological tool to investigate vascular NADPH oxidase should be discontinued.
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Affiliation(s)
- Torsten Schlüter
- Department of Physiology, University of Greifswald, Greifswalder Street 11c, D17495 Greifswald, Karlsburg, Germany
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Soukhova-O'Hare GK, Ortines RV, Gu Y, Nozdrachev AD, Prabhu SD, Gozal D. Postnatal Intermittent Hypoxia and Developmental Programming of Hypertension in Spontaneously Hypertensive Rats. Hypertension 2008; 52:156-62. [DOI: 10.1161/hypertensionaha.108.110296] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Obstructive and central apneas during sleep are associated with chronic intermittent hypoxia (CIH) and increased cardiovascular morbidity. Spontaneously hypertensive rats exposed to CIH during postnatal days 4 to 30 develop exaggerated hypertension as adults. We hypothesized that reactive oxygen species and altered L-Ca
2+
channel activity may underlie the postnatal programming of exaggerated blood pressure and cardiac remodeling. Newborn male spontaneously hypertensive rats were exposed to CIH (10% and 21% O
2
alternating every 90 seconds, 12 h/d, for postnatal days 4 to 30) or normoxia (room air). In each condition, spontaneously hypertensive rats received daily (SC) 1 of 3 treatments:
l
-calcium channel blocker nifedipine (5 mg/kg), superoxide dismutase mimetic MnTMPyP pentachloride (10 mg/kg), or vehicle (polyethylene glycol). Blood pressure was evaluated monthly for 6 months after birth, and echocardiographic assessments were conducted at 6 months of age. CIH vehicle-treated rats presented higher systolic blood pressure (187±5 mm Hg) as compared with normoxic vehicle treated controls (163±2 mm Hg;
P
<0.001). Postnatal CIH elicited marked increases in left ventricular wall thickness in a pattern of concentric hypertrophy with augmented systolic contractility. The treatment with nifedipine in the CIH group attenuated blood pressure (159±2 mm Hg;
P
<0.001) and normalized left ventricular wall thickness and systolic function, whereas the treatment with SOD mimetic decreased blood pressure (165±2 mm Hg;
P
<0.001) and reduced left ventricular wall thickness without changes in the systolic function. We conclude that Ca
2+
and reactive oxygen species–mediated signaling during intermittent hypoxia are critical mechanisms underlying postnatal programming of an increased severity of hypertension and hypertrophic cardiac remodeling in a genetically susceptible rodent model.
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Affiliation(s)
- Galia K. Soukhova-O'Hare
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
| | - Roger V. Ortines
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
| | - Yan Gu
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
| | - Alexander D. Nozdrachev
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
| | - Sumanth D. Prabhu
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
| | - David Gozal
- From the Kosair Children’s Hospital Research Institute (G.K.S-O., D.G.), Department of Pediatrics, Institute of Molecular Cardiology (R.V.O., Y.G., S.D.P.), Department of Medicine, and Department of Pharmacology and Toxicology (D.G.), University of Louisville, Ky; Department of General Physiology (G.K.S-O., A.D.N.), St Petersburg State University, St Petersburg, Russia; Medical Service (S.D.P.), and the Louisville Veterans’ Affairs Medical Center, Louisville, Ky
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Kerkeni M, Added F, Ben Farhat M, Miled A, Trivin F, Maaroufi K. Hyperhomocysteinaemia and parameters of antioxidative defence in Tunisian patients with coronary heart disease. Ann Clin Biochem 2008; 45:193-8. [PMID: 18325185 DOI: 10.1258/acb.2007.007066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND An imbalance between oxidative damage and antioxidative protection in association with the pathophysiology of atherosclerosis has been suggested. The aim of this study was to test the parameters of antioxidative defence and to assess their association with hyperhomocysteinaemia and the severity of coronary heart disease (CHD) in Tunisian patients. METHODS The study population included 100 patients with CHD and 120 healthy controls. The severity of CHD was expressed as the number of affected vessels. Superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity and total antioxidant status (TAS) concentrations were measured using commercially available methods. Plasma total homocysteine (tHcy) concentration was determined by direct chemiluminescence assay. Serum zinc (Zn) was measured by a colorimetric method. RESULTS Compared with healthy control subjects, patients with CHD had significantly lower activities of SOD (P < 0.01), GPx (P < 0.001), and serum Zn concentrations (P < 0.001) and significantly higher tHcy concentration (P < 0.001). However TAS concentrations were not significantly different between the groups. SOD and GPx activities were negatively correlated with tHcy concentration (P < 0.05, P < 0.001, respectively). Patients with hyperhomocysteinaemia showed a lower GPx and SOD activities than patients with normohomocysteinaemia. Antioxidant enzyme activities tended to be decreased in CHD patients presenting with 0- to 3-vessel stenosis. CONCLUSIONS This study indicates that low activity of GPx, SOD and Zn concentration are associated with CHD patients. We hypothesize that hyperhomocysteinaemia and low antioxidant enzyme activities may increase the extent of CHD.
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Affiliation(s)
- Mohsen Kerkeni
- Research Unit 03/UR/08-14, Faculty of Pharmacy, 5000 Monastir, Tunisia.
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Abstract
Oxidative stress plays an important role in the pathogenesis of hypertension. A number of sources of reactive oxygen species have been identified including NADPH oxidase, endothelial NO synthase, and xanthine oxidase. Inhibitors of these systems reduce blood pressure in experimental models. Targeted overexpression of antioxidant systems and interference with expression of oxidant systems has also been successfully used in animal models of hypertension. It is expected that these strategies will eventually be translated to human disease, but currently, the specificity and toxicity of such measures are not yet fulfilling quality criteria for treatment of humans. In the meantime, presumably nontoxic measures, such as administration of antioxidant vitamins, are the only available treatments for oxidative stress in humans. In this review, we discuss strategies to target oxidative stress both in experimental models and in humans. We also discuss how patients could be selected who particularly benefit from antioxidant treatment. In clinical practice, diagnostic procedures beyond measurement of blood pressure will be necessary to predict the response to antioxidants; these procedures will include measurement of antioxidant status and detailed assessment of vascular structure and function.
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Affiliation(s)
- Christian Delles
- BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, Scotland
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Watson T, Goon PKY, Lip GYH. Endothelial progenitor cells, endothelial dysfunction, inflammation, and oxidative stress in hypertension. Antioxid Redox Signal 2008; 10:1079-88. [PMID: 18315493 DOI: 10.1089/ars.2007.1998] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
With a prevalence in excess of 20%, hypertension is a common finding among Western adult populations. Hypertension is directly implicated in the pathophysiology of various cardiovascular disease states and is a significant contributor to ill health, leading to an excess of both morbidity and mortality. The etiology of hypertension has been explored in depth, but the pathophysiology is multifactorial, complex, and poorly understood. Recent interest has been directed toward investigating the purported role of the endothelium, which acts as an important regulator of vascular homeostasis. Endothelial dysfunction is now recognized to occur in hypertension, regardless of whether the etiology is essential or secondary to endocrine or renal processes. Nitric oxide (NO) is a volatile gas produced by endothelial cells that acts to maintain vascular tone. Reduced bioavailability of NO appears to be the key process through which endothelial dysfunction is manifested in hypertension. The result is of an imbalance of counteracting mechanisms, normally designed to maintain vascular homeostasis, leading to vasoconstriction and impaired vascular function. It has become increasingly apparent that these changes may be effected in response to enhanced oxidative stress, possibly as a result of systemic and localized inflammatory responses. This article provides an overview of endothelial dysfunction in hypertension and focuses on the purported role of oxidative stress and inflammation as the catalysts for this process.
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Affiliation(s)
- Timothy Watson
- Haemostasis Thrombosis and Vascular Biology Unit, University Department of Medicine, City Hospital, Birmingham, England
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66
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Abstract
Nitric oxide (NO) has multiple protective effects for regulating the cardiovascular and renal systems. The major functions include endothelium-dependent relaxation, anti-inflammatory effects, as well as antihypertrophic and antithrombotic activities. Many of the activities mediated by NO are systematically antagonized by angiotensin-II (Ang II), a vasconstrictor peptide. Studies described in the review below have demonstrated that the balance between NO and Ang II activities rather than the absolute concentration of each molecule determines their effects on the physiology and pathophysiology of the cardiovascular and renal systems. NO donors have been used for years as therapeutic agents for a range of cardiovascular conditions including angina, myocardial infarction and for the reduction of arterial stiffness. An understanding of the mechanisms underlying the effects of these medications will enable the development of novel therapies to balance the effects of NO in the cardiovascular system.
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Affiliation(s)
- Leopoldo Raij
- Nephrology/Hypertension Division, University of Miami, Veterans Affairs Medical Center, Miami, FL, USA.
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Levonen AL, Vähäkangas E, Koponen JK, Ylä-Herttuala S. Antioxidant gene therapy for cardiovascular disease: current status and future perspectives. Circulation 2008; 117:2142-50. [PMID: 18427144 DOI: 10.1161/circulationaha.107.718585] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Excessive production of reactive oxygen species has been implicated to play an important role in a number of cardiovascular pathologies, including hypertension, atherosclerosis, myocardial infarction, ischemia/reperfusion injury, and restenosis after angioplasty or venous bypass grafting. The formation of reactive oxygen species is balanced out by antioxidant defenses, and augmenting this defense by antioxidant therapies could therefore provide a potential means to treat conditions in which the formation of reactive oxygen species exceeds the capability of natural protective mechanisms. In this review, we summarize the studies in which antioxidant gene therapy has been used successfully to treat cardiovascular diseases. We also discuss the current limitations of antioxidant gene therapy and envision future therapeutic targets and methodological approaches for an improved outcome.
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Affiliation(s)
- Anna-Liisa Levonen
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute, University of Kuopio, Finland.
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68
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Miloradović Z, Jovović Đ, Mihailović-Stanojević N, Milanović JG, Milanović S. Effects of long-term losartan andl-arginine treatment on haemodynamics, glomerular filtration, and SOD activity in spontaneously hypertensive ratsThis article is one of a selection of papers published in the special issue Bridging the Gap: Where Progress in Cardiovascular and Neurophysiologic Research Meet. Can J Physiol Pharmacol 2008; 86:210-4. [DOI: 10.1139/y08-022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, it has been reported that losartan, an angiotensin II receptor (ATR) antagonist, depresses the angiotensin II-induced production of superoxide radicals. Also, in spontaneously hypertensive rats (SHR) endothelial dysfunction is associated with decreased nitric oxide (NO) synthesis. In this study, we examined the effects of long-term ATR blockade and l-arginine supplementation on the haemodynamic parameters, glomerular filtration, and oxidative status in SHR. Adult male SHR were treated with losartan (10 mg/kg) and with the NO donor l-arginine (2 g/kg) for 4 weeks. The animals were divided into the following experimental groups: control (n = 7), l-arginine (n = 7), losartan (n = 7), and l-arginine + losartan (n = 7). Mean arterial pressure (MAP), regional blood flow, urea clearance, and activity of superoxide dismutase (SOD) were measured at the end of treatment. MAP was significantly reduced in the losartan group compared with the control group (133.3 ± 7.3 vs. 161.5 ± 14.5 mm Hg). Aortic blood flow was significantly higher and aortic vascular resistance was significantly lower in all treated groups than in the control. Urea clearance rose significantly in the l-arginine + losartan group compared with control (393.27 ± 37.58 vs. 218.68 ± 42.03 μL·min–1·100 g–1), as did the activity of SOD (1668.97 ± 244.57 vs. 1083.18 ± 169.96 U/g Hb). Our results suggest that the antihypertensive effect of losartan and l-arginine in SHR is not primarily mediated by increased SOD activity. Also, combined treatment with ATR blockade and l-arginine supplementation has a beneficial effect on renal function that is, at least in part, mediated by increased SOD activity in SHR.
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Affiliation(s)
- Zoran Miloradović
- Institute for Medical Research, Dr Subotića 4, P.O. Box 102, Belgrade11129, Serbia
| | - Đurđica Jovović
- Institute for Medical Research, Dr Subotića 4, P.O. Box 102, Belgrade11129, Serbia
| | | | | | - Slađan Milanović
- Institute for Medical Research, Dr Subotića 4, P.O. Box 102, Belgrade11129, Serbia
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69
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Mignini F, Streccioni V, Tomassoni D, Traini E, Amenta F. Comparative crossover, randomized, open-label bioequivalence study on the bioequivalence of two formulations of thioctic acid in healthy volunteers. Clin Exp Hypertens 2008; 29:575-86. [PMID: 18058482 DOI: 10.1080/10641960701744111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
An open-label, randomized, crossover single-dose study, using two periods and two sequences with a washout period of seven days was conducted to assess the comparative bioavailability of thioctic (alpha-lipoic) acid (ALA) 600 mg formulation and that of a reference formulation. Blood samples were collected up to +6 h post dosing, the plasma was separated, and thioctic acid concentrations were determined by high-performance liquid chromatographic method with single mass spectrometry detection (HPLC-MS) and a lower limit of quantification of 190.1 ng/ml. Mean values of the individual C(max) were 1338.6 +/- 751.8 ng/ml and 1215.8 +/- 560.5 ng/ml for the test and reference preparations, respectively. Mean +/- standard deviation (SD) total area under the curve up to the last measurable concentration (AUC(t)) was 3510.9 +/- 1088.6 ng x h/ml for the test formulation and 3563.5 +/- 1374.1 ng x h/ml for the reference formulation. Mean +/- SD total area under the curve (AUC(inf)) was 6925.6 +/- 4045.8 ng x h/ml for the test formulation and 7797.1 +/- 5963.1 ng x h/ml for the reference preparation. Terminal elimination half-life was 5.68 +/- 5.05 h for the test and 6.11 +/- 6.15 h for the reference formulations. Time of maximum concentration (t(max)) was 1.24 +/- 1.23 h for the test and 2.05 +/- 1.21 h for the reference formulations. Ninety percent confidence intervals were comprised within the bioequivalence acceptance criteria (80-125%) for all of the parameters analyzed except t(max). The comparison between males and females showed no significant difference for the two drug treatment.
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Affiliation(s)
- Fiorenzo Mignini
- Centro di Ricerche Cliniche, Dipartimento di Medicina Sperimentale e Sanità Pubblica, Università di Camerino, Camerino, Italy
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70
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Qin Z, Reszka KJ, Fukai T, Weintraub NL. Extracellular superoxide dismutase (ecSOD) in vascular biology: an update on exogenous gene transfer and endogenous regulators of ecSOD. Transl Res 2008; 151:68-78. [PMID: 18201674 PMCID: PMC4230486 DOI: 10.1016/j.trsl.2007.10.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 10/10/2007] [Accepted: 10/11/2007] [Indexed: 12/29/2022]
Abstract
Extracellular superoxide dismutase (ecSOD) is the major extracellular scavenger of superoxide (O(2)(.-)) and a main regulator of nitric oxide (NO) bioactivity in the blood vessel wall, heart, lungs, kidney, and placenta. Involvement of O(2)(.-) has been implicated in many pathological processes, and removal of extracellular O(2)(.-) by ecSOD gene transfer has emerged as a promising experimental technique to treat vascular disorders associated with increased oxidant stress. In addition, recent studies have clarified mechanisms that regulate ecSOD expression, tissue binding, and activity, and they have provided new insight into how ecSOD interacts with other factors that regulate vascular function. Finally, studies of a common gene variant in humans associated with disruption of ecSOD tissue binding suggest that displacement of the enzyme from the blood vessel wall may contribute to vascular diseases. The purpose of this review is to summarize recent research findings related to ecSOD function and gene transfer and to stimulate other investigations into the role of this unique antioxidant enzyme in vascular pathophysiology and therapeutics.
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Affiliation(s)
- Zhenyu Qin
- Division of Cardiovascular Disease, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45267, USA.
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71
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Krischek B, Tatagiba M. The influence of genetics on intracranial aneurysm formation and rupture: current knowledge and its possible impact on future treatment. Adv Tech Stand Neurosurg 2008; 33:131-147. [PMID: 18383813 DOI: 10.1007/978-3-211-72283-1_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The etiology of intracranial aneurysm formation and rupture remains mostly unknown, but lately several studies have increasingly supported the role of genetic factors. In reports so far, genome-wide linkage studies suggest several susceptibility loci that may contain one or more predisposing genes. Depending on the examined ethnic population, several different non-matching chromosomal regions have been found. Studies of several candidate genes report association with intracranial aneurysms. To date, no single gene has been identified as responsible for intracranial aneurysm formation or rupture. In addition to the well-published environmental factors, such as alcohol intake, hypertension and smoking, only the recent progress in molecular genetics enables us to investigate the possible genetic determinants of this disease. Although a familial predisposition is the strongest risk factor for the development of intracranial aneurysms, the mode of Mendelian inheritance is uncertain in most families. Therefore, multiple genetic susceptibilities in conjunction with the environmental factors are considered to act together in the disease's etiology. Accordingly, researchers performed linkage studies and case-control association studies for the genetic analysis and have identified several genes to be susceptible to intracranial aneurysms. The identification of susceptible genes may lead to the understanding of the mechanism of formation and rupture and possibly lead to the development of a pharmacological therapy. Furthermore, should it be possible to identify a genetic marker associated with an increased risk of formation and rupture of an intracranial aneurysm, the necessity for screening and urgency of treatment could be determined more easily. In this review we summarize the current knowledge of intracranial aneurysm genetics and also discuss the method to detect the causalities. In view of the recent advances made in this field, we also give an outlook on possible future genetically engineered therapies, whose development are well underway.
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Affiliation(s)
- B Krischek
- Department of Neurosurgery, University of Tuebingen, Tuebingen, Germany
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72
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Natriuretic peptides in vascular physiology and pathology. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 268:59-93. [PMID: 18703404 DOI: 10.1016/s1937-6448(08)00803-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Four major natriuretic peptides have been isolated: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), and Dendroaspis-type natriuretic peptide (DNP). Natriuretic peptides play an important role in the regulation of cardiovascular homeostasis maintaining blood pressure and extracellular fluid volume. The classical endocrine effects of natriuretic peptides to modulate fluid and electrolyte balance and vascular smooth muscle tone are complemented by autocrine and paracrine actions that include regulation of coronary blood flow and, therefore, myocardial perfusion; modulation of proliferative responses during myocardial and vascular remodeling; and cytoprotective anti-ischemic effects. The actions of natriuretic peptides are mediated by the specific binding of these peptides to three cell surface receptors: type A natriuretic peptide receptor (NPR-A), type B natriuretic peptide receptor (NPR-B), and type C natriuretic peptide receptor (NPR-C). NPR-A and NPR-B are guanylyl cyclase receptors that increase intracellular cGMP concentration and activate cGMP-dependent protein kinases. NPR-C has been presented as a clearance receptor and its activation also results in inhibition of adenylyl cyclase activity. The wide range of effects of natriuretic peptides might be the base for the development of new therapeutic strategies of great benefit in patients with cardiovascular problems including coronary artery disease or heart failure. This review summarizes current literature concerning natriuretic peptides, their receptors and their effects on fluid/electrolyte balance, and vascular and cardiac physiology and pathology, including primary hypertension and myocardial infarction. In addition, we will attempt to provide an update on important issues regarding natriuretic peptides in congestive heart failure.
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73
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Heistad DD, Watanabe Y, Chu Y. Gene transfer after subarachnoid hemorrhage: a tool and potential therapy. ACTA NEUROCHIRURGICA. SUPPLEMENT 2008; 104:157-159. [PMID: 18457000 DOI: 10.1007/978-3-211-75718-5_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This mini-review describes steps towards gene therapy to prevent vasospasm after subarachnoid hemorrhage, and summarizes some remaining obstacles. With recombinant adenoviruses, it is now possible to prevent vasospasm in experimental animals. If an adenoviral or other effective vector is demonstrated to be safe, it is likely that gene therapy will be used in patients to prevent vasospasm.
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Affiliation(s)
- D D Heistad
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242-1081, USA.
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74
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Carey RM. Pathophysiology of Primary Hypertension. Microcirculation 2008. [DOI: 10.1016/b978-0-12-374530-9.00020-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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75
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Biswas SK, Peixoto EB, Souza DS, de Faria JBL. Hypertension increases pro-oxidant generation and decreases antioxidant defense in the kidney in early diabetes. Am J Nephrol 2007; 28:133-42. [PMID: 17951995 DOI: 10.1159/000109993] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 08/17/2007] [Indexed: 12/24/2022]
Abstract
AIMS The combination of hypertension and diabetes exacerbates renal oxidative stress. The aim of the present study was therefore to evaluate the pro-oxidant and antioxidant mechanisms responsible for the induction of renal oxidative stress in the presence of hypertension and diabetes mellitus. METHODS Diabetes was induced in spontaneously hypertensive rats (SHR) and their genetically normotensive control Wistar-Kyoto (WKY) rats by streptozotocin at 12 weeks of age. After 10 days, pro-oxidant, antioxidant and oxidative stress parameters were evaluated in the renal tissue. RESULTS NADPH oxidase-dependent superoxide generation in the renal cortex was significantly elevated in WKY and SHR diabetic (D) groups compared to the respective control (C) groups (p < 0.005, n = 5). However, the highest level of superoxide generation was observed in the SHR-D group compared to all other groups. The expression of the gp91phox subunit of NADPH oxidase was significantly elevated in the SHR-D (p < 0.05, n = 5), but not in the WKY-D group, compared to the respective control groups. The renal cortical extracellular-superoxide dismutase level was found to be markedly decreased in the SHR groups compared to the WKY groups (p < 0.05, n = 5). The antioxidant glutathione level was found to be lower in the SHR-D (p = 0.03, n = 15), but not in the WKY-D group, compared to the respective control groups. Finally, nitrotyrosine and 8-hydroxy-2'-deoxyguanosine, markers of oxidative stress, were found to be similar in the kidneys of WKY-C and WKY-D, but were elevated in the SHR-D compared to the SHR-C group. CONCLUSION We therefore conclude that hypertension increases pro-oxidant generation and decreases antioxidant defense, and thereby induces renal oxidative stress in early diabetes.
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Affiliation(s)
- Subrata K Biswas
- Renal Pathophysiology Laboratory, Division of Nephrology, Department of Internal Medicine, Faculty of Medical Sciences, State University of Campinas, Campinas, São Paulo, Brazil
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76
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Krumova E, Dolashki A, Pashova S, Dolashka-Angelova P, Stevanovic S, Hristova R, Stefanova L, Voelter W, Angelova M. Unusual location and characterization of Cu/Zn-containing superoxide dismutase from filamentous fungus Humicola lutea. Arch Microbiol 2007; 189:121-30. [PMID: 17805512 DOI: 10.1007/s00203-007-0300-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2007] [Revised: 07/20/2007] [Accepted: 08/09/2007] [Indexed: 10/22/2022]
Abstract
The present study aims to provide new information about the unusual location of Cu/Zn-superoxide dismutase (Cu/Zn-SOD) in lower eukaryotes such as filamentous fungi. Humicola lutea, a high producer of SOD was used as a model system. Subcellular fractions [cytosol, mitochondrial matrix, and intermembrane space (IMS)] were isolated and tested for purity using activity measurements of typical marker enzymes. Evidence, based on electrophoretic mobility, sensitivity to KCN and H(2)O(2) and immunoblot analysis supports the existence of Cu/Zn-SOD in mitochondrial IMS, and the Mn-SOD in the matrix. Enzyme activity is almost equally partitioned between both the compartments, thus suggesting that the intermembrane space could be one of the major sites of exposure to superoxide anion radicals. The mitochondrial Cu/Zn-SOD was purified and compared with the previously published cytosolic enzyme. They have identical molecular mass, cyanide- and H(2)O(2)-sensitivity, N-terminal amino acid sequence, glycosylation sites and carbohydrate composition. The H. lutea mitochondrial Cu/Zn-SOD is the first identified naturally glycosylated enzyme, isolated from IMS. These findings suggest that the same Cu/Zn-SOD exists in both the mitochondrial IMS and cytosol.
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Affiliation(s)
- Ekaterina Krumova
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
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77
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Lund DD, Chu Y, Brooks RM, Faraci FM, Heistad DD. Effects of a common human gene variant of extracellular superoxide dismutase on endothelial function after endotoxin in mice. J Physiol 2007; 584:583-90. [PMID: 17717013 PMCID: PMC2277153 DOI: 10.1113/jphysiol.2007.140830] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A common gene variant in the heparin-binding domain (HBD) of extracellular superoxide dismutase (ECSOD) may predispose human carriers to ischaemic heart disease. We have demonstrated that the HBD of ECSOD is important for ECSOD to restore vascular dysfunction produced by endotoxin. The purpose of this study was to determine whether the gene variant in the HBD of ECSOD (ECSOD(R213G)) protects against endothelial dysfunction in a model of inflammation. We constructed a recombinant adenovirus that expresses ECSOD(R213G). Adenoviral vectors expressing ECSOD, ECSOD(R213G) or beta-galactosidase (LacZ, a control) were injected i.v. in mice. After 3 days, at which time the plasma SOD activity is maximal, vehicle or endotoxin (lipopolysaccharide or LPS, 40 mg kg(-1)) was injected i.p. Vasomotor function of aorta in vitro was examined 1 day later. Maximal relaxation to sodium nitroprusside was similar in aorta from normal and LPS-treated mice. Maximal relaxation to acetylcholine (10(-5)) was impaired after LPS and LacZ (63 +/- 3%, mean +/- s.e.m.) compared to normal vessels (83 +/- 3%) (P < 0.05). Gene transfer of ECSOD improved (P < 0.05) relaxation in response to acetylcholine (76 +/- 5%) after LPS, whereas gene transfer of ECSOD(R213G) had no effect (65 +/- 4%). Superoxide was increased in aorta (measured using lucigenin and hydroethidine) after LPS, and levels of superoxide were significantly reduced following ECSOD but not ECSOD(R213G). Thus, ECSOD reduces superoxide and improves relaxation to acetylcholine in the aorta after LPS, while the ECSOD variant R213G had minimal effect. These findings suggest that, in contrast to ECSOD, the common human gene variant of ECSOD fails to protect against endothelial dysfunction produced by an inflammatory stimulus.
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Affiliation(s)
- Donald D Lund
- Department of Internal Medicine, Cardiovascular Center, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
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78
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Kim HW, Lin A, Guldberg RE, Ushio-Fukai M, Fukai T. Essential role of extracellular SOD in reparative neovascularization induced by hindlimb ischemia. Circ Res 2007; 101:409-19. [PMID: 17601801 DOI: 10.1161/circresaha.107.153791] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Neovascularization is an important physiological repair mechanism in response to ischemic injury, and its process is dependent on reactive oxygen species (ROS). Overproduction of superoxide anion (O2-) rather contributes to various cardiovascular diseases. The extracellular superoxide dismutase (ecSOD) is one of the major antioxidant enzymes against O2- in blood vessels; however, its role in neovascularization induced by tissue ischemia is unknown. Here we show that hindlimb ischemia of mice stimulates a significant increase in ecSOD activity in ischemic tissues where ecSOD protein is highly expressed at arterioles. In mice lacking ecSOD, ischemia-induced increase in blood flow recovery, collateral vessel formation, and capillary density are significantly inhibited. Impaired neovascularization in ecSOD(-/-) mice is associated with enhanced O2- production, TUNEL-positive apoptotic cells and decreased levels of NO2-/NO3- and cGMP in ischemic tissues as compared with wild-type mice, and it is rescued by infusion of the SOD mimetic tempol. Recruitment of inflammatory cells into ischemic tissues as well as numbers of inflammatory cells and endothelial progenitor cells (c-kit+/CD31+ cells) in both peripheral blood and bone marrow (BM) are significantly reduced in these knockout mice. Of note, ecSOD expression is markedly increased in BM after ischemia. NO2-/NO3- and cGMP levels are decreased in ecSOD(-/-) BM. Transplantation of wild-type BM into ecSOD(-/-) mice rescues the defective neovascularization. Thus, ecSOD in BM and ischemic tissues induced by hindlimb ischemia may represent an important compensatory mechanism that blunts the overproduction of O2-, which may contribute to reparative neovascularization in response to ischemic injury.
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Affiliation(s)
- Ha Won Kim
- Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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79
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Abstract
Gene therapy is a promising approach for treatment of stroke and other cerebrovascular diseases, although it may take many years to realize. Gene therapy could occur prior to a stroke (eg, to stabilize atherosclerotic plaques) and/or following a stroke (eg, to prevent vasospasm after subarachnoid hemorrhage or reduce injury to neurons by ischemic insult). We have transferred the gene coding for vasoactive calcitonin gene-related peptide via cerebrospinal fluid, and demonstrated attenuation of vasospasm after SAH. Transfer of neuroprotective genes or small interfering RNA for neurotoxic genes has good potential for ischemic stroke. In this brief report, we review recent developments in experimental gene therapy for stroke. Fundamental advances, including development of safer, more specific gene transfer vectors, are discussed.
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Affiliation(s)
- Yi Chu
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA
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80
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Fukai T. Extracellular SOD inactivation in high-volume hypertension: role of hydrogen peroxide. Arterioscler Thromb Vasc Biol 2007; 27:442-4. [PMID: 17301320 DOI: 10.1161/01.atv.0000258920.36436.8e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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81
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Jung O, Marklund SL, Xia N, Busse R, Brandes RP. Inactivation of Extracellular Superoxide Dismutase Contributes to the Development of High-Volume Hypertension. Arterioscler Thromb Vasc Biol 2007; 27:470-7. [PMID: 17170376 DOI: 10.1161/01.atv.0000254823.15843.1f] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives—
Extracellular superoxide dismutase (ecSOD) lowers superoxide anions and maintains vascular nitric oxide level. We studied the function of ecSOD in high-volume hypertension induced by the 1-kidney-1-clip model in wild-type, ecSOD
−/−
mice, and endothelial nitric oxide synthase (eNOS)
−/−
mice.
Methods and Results—
The 1-kidney–1-clip model resulted in impaired endothelium-dependent relaxation and hypertension and vascular oxidative stress in wild-type and ecSOD
−/−
mice. Recombinant ecSOD lowered the blood pressure and improved aortic nitric oxide bioavailability in wild-type and ecSOD
−/−
but not eNOS
−/−
mice. ecSOD had no effect on blood pressure in eNOS
−/−
or wild-type mice treated with a nitric oxide synthase inhibitor. The 1-kidney–1-clip model markedly induced ecSOD protein expression, whereas activity was increased by only 25%, suggesting a partial inactivation of ecSOD in high-volume hypertension. Incubation of aortic segments with peroxynitrite or hydrogen peroxide attenuated ecSOD activity, but peroxynitrite did not induce tyrosine nitration of ecSOD, suggesting oxidative inactivation of the enzyme. Administration of polyethyleneglycol-catalase for 3 days selectively lowered the blood pressure in ecSOD
+/+
but not ecSOD
−/−
mice and improved nitric oxide bioavailability. In contrast, acute application of catalase had no effect.
Conclusions—
Nitric oxide mediates the vascular effects of ecSOD. Vascular dysfunction in 1-kidney–1-clip model hypertension is partially a consequence of inactivation of ecSOD by reactive oxygen species.
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Affiliation(s)
- Oliver Jung
- Institut für Kardiovaskuläre Physiologie, Klinikum der J.W. Goethe-Universität, Theodor-Stern-Kai 7, D-60596 Frankfurt am Main, Germany
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82
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Sullivan JC, Sasser JM, Pollock JS. Sexual dimorphism in oxidant status in spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2007; 292:R764-8. [PMID: 16917021 DOI: 10.1152/ajpregu.00322.2006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Male spontaneously hypertensive rats (SHR) have a blunted pressure-natriuresis relationship and enhanced oxidative stress compared with female SHR. Furthermore, oxidative stress contributes to abnormal renal Na+ handling and renal damage in hypertension. The aim of this study was to determine whether a sex difference exists in renal inner medullary hydrogen peroxide (H2O2) levels and/or antioxidant systems in SHR and the influence of sex steroids on these systems. Thirteen-week-old intact and gonadectomized male and female SHR were placed in metabolic cages for 24-h urine collection. Renal inner medullas were isolated for antioxidant activity assays and Western blot analysis or for measurements of H2O2 using Amplex Red. Studies verified that male SHR had greater Na+ reabsorption compared with female SHR. Male SHR had enhanced urinary excretion of H2O2 compared with female SHR. Gonadectomy decreased H2O2 excretion in males and increased H2O2 excretion in females, suggesting that testosterone stimulates total body oxidative stress and estrogen suppresses levels of total body oxidative stress. There was not a sex difference in inner medullary H2O2 levels. Male SHR had a testosterone-dependent increase in inner medullary SOD activity, and both intact and gonadectomized males had high levels of inner medullary catalase activity compared with females. The results of this study showed that there was a sexual dimorphism in Na+ handling and oxidant status. We hypothesize that there is a testosterone-sensitive increase in whole body reactive oxygen species production that results in a compensatory increase in the inner medullary antioxidant capability possibly to normalize Na+ handling.
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Affiliation(s)
- Jennifer C Sullivan
- Medical College of Georgia, Vascular Biology Center, 1459 Laney-Walker Blvd., Augusta, GA 30912, USA.
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83
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Mirossay A, Jun S, Dory L. Cloning and characterization of two alleles of the murine extracellular superoxide dismutase gene. Biochem Biophys Res Commun 2006; 352:739-43. [PMID: 17150184 DOI: 10.1016/j.bbrc.2006.11.081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Accepted: 11/16/2006] [Indexed: 11/23/2022]
Abstract
We have recently documented the existence of a second allele of ecSOD in mice. Thus far, this allele was only found in the 129P3/J strain. It is characterized by two point mutations leading to amino acid changes as well as a 10 bp deletion from the 3' UTR. We have also shown that the phenotype is profoundly affected by the genotype. In order to obtain a tool to investigate the differences in the properties as well as the posttranscriptional regulation of expression of the two alleles we now describe the creation and characterization of stably transfected CHO-K1 cell lines expressing either of these alleles. CHO-K1 cells were chosen because they do not express endogenous ecSOD and are easy to transfect. We demonstrate that the transfected cells secrete substantial amounts of glycosylated ecSOD, detected by Western blot analyses, ConA-Sepharose affinity chromatography and activity measurements.
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Affiliation(s)
- Andrej Mirossay
- Department of Molecular Biology and Immunology, The University of North Texas Health Science Centre at Fort Worth, Fort Worth, TX 76107, USA
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84
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Welch WJ, Chabrashvili T, Solis G, Chen Y, Gill PS, Aslam S, Wang X, Ji H, Sandberg K, Jose P, Wilcox CS. Role of Extracellular Superoxide Dismutase in the Mouse Angiotensin Slow Pressor Response. Hypertension 2006; 48:934-41. [PMID: 17015770 DOI: 10.1161/01.hyp.0000242928.57344.92] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Low rates of angiotensin II (Ang II) infusion raise blood pressure, renal vascular resistance (RVR), NADPH oxidase activity, and superoxide. We tested the hypothesis that these effects are ameliorated by extracellular superoxide dismutase (EC-SOD). EC-SOD knockout (-/-) and wild type (+/+) mice were equipped with blood pressure telemeters and infused subcutaneously with Ang II (400 ng/kg per minute) or vehicle for 2 weeks. During vehicle infusion, EC-SOD -/- mice had significantly (P<0.05) higher MAP (+/+: 107+/-3 mm Hg versus -/-: 114+/-2 mm Hg; n=11 to 14), RVR, lipid peroxidation, renal cortical p22(phox) expression, and NADPH oxidase activity. Ang II infusion in EC-SOD +/+ mice significantly (P<0.05) increased MAP, RVR, p22(phox), NADPH oxidase activity, and lipid peroxidation. Ang II reduced SOD activity in plasma, aorta, and kidney accompanied by reduced renal EC-SOD expression. During Ang II infusion, both groups had similar values for MAP (+/+ Ang II: 125+/-3 versus -/- Ang II: 124+/-3 mmHg; P value not significant), RVR, NADPH oxidase activity, and lipid peroxidation. SOD activity in the kidneys of Ang II-infused mice was paradoxically higher in EC-SOD -/- mice (+/+: 8.8+/-1.2 U/mg protein(-1) versus -/-: 13.7+/-1.6 U/mg protein(-1); P<0.05) accompanied by a significant upregulation of mRNA and protein for Cu/Zn-SOD. In conclusion, EC-SOD protects normal mice against oxidative stress by attenuating renal p22(phox) expression, NADPH oxidase activation, and the accompanying renal vasoconstriction and hypertension. However, during an Ang II slow pressor response, renal EC-SOD expression is reduced and, in its absence, renal Cu/Zn-SOD is upregulated and may prevent excessive Ang II-induced renal oxidative stress, renal vasoconstriction, and hypertension.
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Affiliation(s)
- William J Welch
- Cardiovascular-Kidney Institute and Division of Nephrology and Hypertension, Georgetown University, Washington, DC, USA
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85
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Romero N, Denicola A, Radi R. Red blood cells in the metabolism of nitric oxide-derived peroxynitrite. IUBMB Life 2006; 58:572-80. [PMID: 17050374 DOI: 10.1080/15216540600936549] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In this review we have analyzed the reactions of nitric oxide (.NO) with superoxide radical (O(2).-) at the vascular compartment which results in limitation of the bioavailability of .NO and the formation of peroxynitrite (ONOO-), a strong oxidant species. The intravascular formation of peroxynitrite can result in oxidative modifications of plasma and vessel wall proteins including the formation of protein-3-nitrotyrosine. The role of red blood cells (RBC) and oxyhemoglobin in the metabolism of intravascular peroxynitrite will be discussed. While RBC constitute an important 'sink' of both .NO and peroxynitrite, redox reactions of these species with oxyhemoglobin may in part contribute to erythrocyte aging. The intravascular formation, reactions and detoxification of peroxynitrite are revealed as important factors controlling vascular dysfunction and degeneration in a variety of pathophysiologically-relevant conditions.
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Affiliation(s)
- Natalia Romero
- Departamento de Bioquímica, Facultad de Medicina, , Universidad de la República, Montevideo, Uruguay
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86
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Abstract
It is now feasible to transfer genes to blood vessels to alter vascular function. An alternative approach is to transfer genes to liver or skeletal muscle, so that the transgene releases a protein into blood, and the protein binds to blood vessels to alter vascular function. Gene therapy is being tested for treatment of diseases, such as ischemia in patient with peripheral vascular disease, which cannot be treated with medications. Common diseases, such as hypertension and hypercholesterolemia, also may be targets for gene therapy. Periodic intravenous injection of a vector for gene transfer has the potential for circumventing poor compliance in taking daily medications for these diseases. The key obstacle to widespread use of gene therapy is that a safe and efficient vector for delivery of genes has not yet been developed.
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Affiliation(s)
- Donald D Heistad
- Department of Internal Medicine, University of Iowa Carver College of Medicine, VA Medical Center, Iowa City, Iowa, United States.
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87
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Tasaki H, Yamashita K, Tsutsui M, Kamezaki F, Kubara T, Tanaka S, Sasaguri Y, Adachi T, Nakashima Y. Heparin-released extracellular superoxide dismutase is reduced in patients with coronary artery atherosclerosis. Atherosclerosis 2006; 187:131-8. [PMID: 16191429 DOI: 10.1016/j.atherosclerosis.2005.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 08/03/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES We studied whether the amount of heparin-released extracellular superoxide dismutase (EC-SOD), which is an antioxidative enzyme, is associated with coronary artery disease (CAD). METHODS AND RESULTS EC-SOD was measured in plasma at basal and at post-heparin injection in 315 patients. Heparin-released EC-SOD was calculated as the difference between the two values. After exclusion of a mutant EC-SOD group (n = 27:8.6%), 288 patients were divided into three groups by angiographic findings; those with normal coronary (the normal group; n = 63), those with atherosclerosis without significant stenosis (the mild atherosclerosis group; n = 36), and those with significant stenosis (the atherosclerosis group; n = 189). Although the basal values were similar among the three groups, heparin-released EC-SOD levels were significantly lower in the atherosclerosis group (131.0 +/- 42.8 ng/ml, p = 0.0003) than in the normal group (156.9 +/- 66.2 ng/ml). Moreover, logistic analysis revealed that heparin-released EC-SOD independently contributed to CAD. The coronary score showed a significant correlation with heparin-released EC-SOD. As for factors affecting the level of heparin-released EC-SOD, the level of high-density lipoprotein cholesterol and age showed a positive correlation. CONCLUSIONS The results suggest that heparin-released EC-SOD is significantly reduced in CAD and that the tissue-bound location of this enzyme might be important for antioxidative function.
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Affiliation(s)
- Hiromi Tasaki
- Second Department of Internal medicine, University of Occupational and Environmental Health, School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
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88
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Chu Y, Piper R, Richardson S, Watanabe Y, Patel P, Heistad DD. Endocytosis of extracellular superoxide dismutase into endothelial cells: role of the heparin-binding domain. Arterioscler Thromb Vasc Biol 2006; 26:1985-90. [PMID: 16809550 DOI: 10.1161/01.atv.0000234921.88489.5c] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Extracellular superoxide dismutase (EC-SOD) is a secreted antioxidant enzyme that binds to the outer plasma membrane and extracellular matrix through its heparin-binding domain (HBD). Carriers of a common genetic variant of EC-SOD (EC-SOD(R213G), within the HBD) have higher plasma concentration of EC-SOD and increased risk for vascular disease. In the present study, we used confocal fluorescence microscopy to examine mechanisms of endocytosis of EC-SOD to determine whether EC-SOD translocates to the nucleus of endothelial cells, and to test the hypothesis that EC-SOD, but not EC-SOD(R213G), is endocytosed into endothelial cells. METHODS AND RESULTS Mouse endothelial cells (MS-1) were incubated with EC-SOD, EC-SOD(R213G), or HBD-deleted EC-SOD (EC-SODdeltaHBD). Binding to MS-1 was observed only with EC-SOD, but not EC-SOD(R213G) or EC-SODdeltaHBD. Endocytosis of EC-SODs was monitored after coincubation of MS-1 cells with EC-SODs and BSA-Texas Red (BSA-TR), which marks endosomes and lysosomes. Only EC-SOD was endocytosed, colocalizing with BSA-TR. EC-SOD also colocalized with early endosome antigen 1 (EEA-1), a specific marker for endocytosis. Endocytosis of EC-SOD was inhibited by chlorpromazine, but not by methyl-beta-cyclodextrin or nystatin, which suggests that endocytosis of EC-SOD is mediated by clathrin but not by caveolae. Minimal or no localization of EC-SOD in the nucleus of MS-1 cells was detected. CONCLUSIONS Our findings indicate that EC-SOD, but not EC-SOD(R213G), is endocytosed into endothelial cells through clathrin-mediated pathway, but does not translocate to the nucleus. We speculate that impairment of endocytosis may contribute to high plasma levels of EC-SOD(R213G) in R213G carriers.
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Affiliation(s)
- Yi Chu
- Cardiovascular Center and Department of Internal Medicine, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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89
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Chan SHH, Tai MH, Li CY, Chan JYH. Reduction in molecular synthesis or enzyme activity of superoxide dismutases and catalase contributes to oxidative stress and neurogenic hypertension in spontaneously hypertensive rats. Free Radic Biol Med 2006; 40:2028-39. [PMID: 16716903 DOI: 10.1016/j.freeradbiomed.2006.01.032] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2005] [Revised: 01/20/2006] [Accepted: 01/26/2006] [Indexed: 11/21/2022]
Abstract
A balance between production and elimination of reactive oxygen species such as superoxide anion (O2*-) and hydrogen peroxide (H2O2) tightly regulates the homeostasis of cellular oxidative stress, which contributes to a variety of cardiovascular diseases, including hypertension. The present study assessed the hypothesis that O2*- or H2O2 levels augmented by the reduced molecular synthesis or enzyme activity of superoxide dismutase (SOD), catalase (CAT), or glutathione peroxidase (GPx) in the rostral ventrolateral medulla (RVLM), where sympathetic premotor neurons that generate tonic vasomotor tone are located, contribute to the pathogenesis of hypertension. We found that copper/zinc SOD (SOD1), manganese SOD (SOD2), or CAT, but not GPx, mRNA or protein expression and enzyme activity in the RVLM of spontaneously hypertensive rats (SHR) were significantly lower than those in normotensive Wistar-Kyoto (WKY) rats, along with a significantly higher level of O2*- or H2O2. A causative relationship between these biochemical correlates of oxidative stress and neurogenic hypertension was established when gene transfer by microinjection of adenovirus encoding SOD1, SOD2, or CAT into the bilateral RVLM promoted a long-lasting reduction in arterial pressure in SHR, but not WKY rats, accompanied by an enhanced SOD1, SOD2, or CAT protein expression or enzyme activity and reduced O2*- or H2O2 level in the RVLM. These results together suggest that downregulation of gene expression and enzyme activity of the antioxidant SOD1, SOD2, or CAT may underlie the augmented levels of O2*- and H2O2 in the RVLM, leading to oxidative stress and hypertension in SHR.
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Affiliation(s)
- Samuel H H Chan
- Center for Neuroscience, National Sun Yat-sen University, Kaohsiung 804, Taiwan, Republic of China
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90
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Donofrio G, Martignani E, Poli E, Lange C, Martini FM, Cavirani S, Cabassi CS, Taddei S, Flammini CF. Bovine herpesvirus 4 based vector interaction with liver cells in vitro and in vivo. J Virol Methods 2006; 136:126-36. [PMID: 16712963 DOI: 10.1016/j.jviromet.2006.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 04/05/2006] [Accepted: 04/06/2006] [Indexed: 11/27/2022]
Abstract
Gene transfer into hepatocytes is highly desirable for the long-term goal of replacing deficient proteins and correcting metabolic disorders. Bovine herpesvirus 4 (BoHV-4) based vector capability to transduce rat liver cells in vitro and in vivo was assessed. For the in vitro study, a buffalo rat liver cell line was successfully transduced by BoHV-4 and although did not show toxicity, the immediate early two viral gene was transcribed and cells harboring the intact viral genome could be pharmacologically selected, but no viral replication took place. For the in vivo study, adult male rats were inoculated intraportally and intraparenchimally with a BoHV-4 expressing enhanced green fluorescent protein and liver sections were analyzed through fluorescent microscopy. Although the liver parenchyma could not be transduced, the endothelial layer of the liver vasculature showed a robust transgene expression without toxicity. Successful BoHV-4 based vector transduction of primary cultures of rat hepatocytes suggests that extrinsic factors, and not hepatocytes per se, are the cause of such lack of transducibility. The present study serves as a starting point for study of the use of BoHV-4 based vectors to target gene delivery to vascular endothelial cells.
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Affiliation(s)
- Gaetano Donofrio
- Dipartimento di Salute Animale, Facoltà di Medicina Veterinaria, Sezione di Malattie Infettive degli Animali, Università di Parma, via del Taglio 8, 43100 Parma, Italy.
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91
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Abstract
There is compelling evidence that oxidative stress plays a key role in the pathophysiology of several major cardiovascular diseases. In atherosclerosis, hypertension, stroke, diabetes, and heart failure, expression of superoxide is increased in blood vessels, and endothelial vasomotor function is impaired, presumably caused in large part by inactivation of nitric oxide by superoxide. Endothelial dysfunction is predictive of cardiovascular risk, and probably plays a key role in the pathophysiology of atherosclerosis and its complications. In preliminary studies in hypercholesterolemic mice and in older humans, we have found high levels of superoxide in the aortic valve, as well as aorta. We speculate that superoxide, in addition to playing a key role in atherogenesis, may play a key role in signaling that leads to calcific aortic valvular stenosis. Antioxidant enzymes, especially the three isoforms of superoxide dismutase (SOD), modulate basal levels of superoxide and protect against vasomotor dysfunction. A common gene variant of extracellular SOD (ecSOD) is associated with increased risk of ischemic heart disease. We have made recombinant adenoviruses to examine cardiovascular effects of ecSOD and its heparin-binding domain. This approach might be used to study the almost 500 other proteins with a heparin-binding domain. Finally, several key unanswered questions in relation to oxidative stress and atherosclerosis are raised, and proposed as fruitful areas of research.
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Affiliation(s)
- Donald D Heistad
- University of Iowa College of Medicine, Iowa City, Iowa 52242-1081, USA
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92
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Brown KA, Chu Y, Lund DD, Heistad DD, Faraci FM. Gene transfer of extracellular superoxide dismutase protects against vascular dysfunction with aging. Am J Physiol Heart Circ Physiol 2006; 290:H2600-5. [PMID: 16443677 DOI: 10.1152/ajpheart.00676.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging is an independent risk factor for cardiovascular disease, but mechanisms leading to vascular dysfunction have not been fully elucidated. Recent studies suggest that oxidative stress may increase in blood vessels during aging. Levels of superoxide are influenced by the activity of SODs. The goal of this study was to examine the effect of extracellular superoxide dismutase (ECSOD) on superoxide levels and vascular function in an animal model of aging. Aortas from young (4-8 mo old) and old (29-31 mo old) Fischer 344 rats were examined in vitro. Relaxation of aorta to ACh was impaired in old rats compared with young rats; e.g., 3 muM ACh produced 57 +/- 4% (mean +/- SE) and 84 +/- 2% relaxation in old and young rats, respectively (P < 0.0001). Three days after gene transfer of adenovirus expressing human ECSOD (AdECSOD), the response to ACh was not affected in young rats but was improved in old rats. There was no difference in relaxation to the endothelium-independent dilator sodium nitroprusside between young, aged, and AdECSOD-treated old rats. Superoxide levels (lucigenin-enhanced chemiluminescence) were significantly increased in aged rats compared with young rats. After gene transfer of ECSOD to aged rats, superoxide levels in aorta were similar in old and young rats. Gene transfer of an ECSOD with the heparin-binding domain deleted had no effect on vascular function or superoxide levels in old rats. These results suggest that 1) vascular dysfunction associated with aging is mediated in part by increased levels of superoxide, 2) gene transfer of ECSOD reduces vascular superoxide and dysfunction in old rats, and 3) beneficial effects of ECSOD in old rats require the heparin-binding domain of ECSOD.
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Affiliation(s)
- Kathryn A Brown
- Department of Pharmacology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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93
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Qin Z, Itoh S, Jeney V, Ushio-Fukai M, Fukai T. Essential role for the Menkes ATPase in activation of extracellular superoxide dismutase: implication for vascular oxidative stress. FASEB J 2005; 20:334-6. [PMID: 16371425 DOI: 10.1096/fj.05-4564fje] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Extracellular superoxide dismutase (SOD3), a secretory copper enzyme, plays an important role in atherosclerosis and hypertension by modulating the levels of extracellular superoxide anion (O2*-) in the vasculature. Little is known about the mechanisms by which SOD3 obtains its catalytic copper cofactor. Menkes ATPase (MNK) has been shown to transport cytosolic copper to the secretory pathway in nonvascular cells. We performed the present study to determine whether MNK is required for the activation of SOD3 in the vasculature. Here we show that MNK was highly expressed in the various vascular tissues and cells. Aortas and cultured fibroblasts from MNK mutant (MNK(mut)) mice showed a marked decrease in specific activity of SOD3, but not SOD1 (cytosolic form), which was partially restored by copper addition. Copper treatment in wild-type cells promoted the direct interaction and colocalization of SOD3 with MNK in the trans-Golgi network (TGN), suggesting that MNK transports copper to SOD3 in the TGN. Aortas of MNK(mut) mice revealed a decrease in activity of SOD3, but not SOD1, in association with a robust increase in O2*- levels. Finally, both MNK and SOD3 proteins were highly expressed in the intimal lesions of atherosclerotic vessels. In conclusion, vascular MNK plays an essential role in full activity of SOD3 through transporting copper to SOD3 in the TGN, thereby regulating O2*- levels in the vasculature. These studies provide a novel insight into vascular MNK as a critical modulator of "superoxide" stress, which may contribute to cardiovascular disease.
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Affiliation(s)
- Zhenyu Qin
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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94
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Rush JWE, Denniss SG, Graham DA. Vascular nitric oxide and oxidative stress: determinants of endothelial adaptations to cardiovascular disease and to physical activity. ACTA ACUST UNITED AC 2005; 30:442-74. [PMID: 16258183 DOI: 10.1139/h05-133] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cardiovascular disease is the single leading cause of death and morbidity for Canadians. A universal feature of cardiovascular disease is dysfunction of the vascular endothelium, thus disrupting control of vasodilation, tissue perfusion, hemostasis, and thrombosis. Nitric oxide bioavailability, crucial for maintaining vascular endothelial health and function, depends on the processes controlling synthesis and destruction of nitric oxide as well as on the sensitivity of target tissue to nitric oxide. Evidence supports a major contribution by oxidative stress-induced destruction of nitric oxide to the endothelial dysfunction that accompanies a number of cardiovascular disease states including hypertension, diabetes, chronic heart failure, and atherosclerosis. Regular physical activity (exercise training) reduces cardiovascular disease risk. Numerous studies support the hypothesis that exercise training improves vascular endothelial function, especially when it has been impaired by preexisting risk factors. Evidence is emerging to support a role for improved nitric oxide bioavailability with training as a result of enhanced synthesis and reduced oxidative stress-mediated destruction. Molecular targets sensitive to the exercise training effect include the endothelial nitric oxide synthase and the antioxidant enzyme superoxide dismutase. However, many fundamental details of the cellular and molecular mechanisms linking exercise to altered molecular and functional endothelial phenotypes have yet to be discovered. The working hypothesis is that some of the cellular mechanisms contributing to endothelial dysfunction in cardiovascular disease can be targeted and reversed by signals associated with regular increases in physical activity. The capacity for exercise training to regulate vascular endothelial function, nitric oxide bioavailability, and oxidative stress is an example of how lifestyle can complement medicine and pharmacology in the prevention and management of cardiovascular disease.
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Affiliation(s)
- James W E Rush
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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95
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Wilcox CS. Oxidative stress and nitric oxide deficiency in the kidney: a critical link to hypertension? Am J Physiol Regul Integr Comp Physiol 2005; 289:R913-35. [PMID: 16183628 DOI: 10.1152/ajpregu.00250.2005] [Citation(s) in RCA: 357] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is growing evidence that oxidative stress contributes to hypertension. Oxidative stress can precede the development of hypertension. In almost all models of hypertension, there is oxidative stress that, if corrected, lowers BP, whereas creation of oxidative stress in normal animals can cause hypertension. There is overexpression of the p22(phox) and Nox-1 components of NADPH oxidase and reduced expression of extracellular superoxide dismutase (EC-SOD) in the kidneys of ANG II-infused rodents, whereas there is overexpression of p47(phox) and gp91(phox) and reduced expression of intracellular SOD with salt loading. Several mechanisms have been identified that can make oxidative stress self-sustaining. Reactive oxygen species (ROS) can enhance afferent arteriolar tone and reactivity both indirectly via potentiation of tubuloglomerular feedback and directly by microvascular mechanisms that diminish endothelium-derived relaxation factor/nitric oxide responses, generate a cyclooxygenase-2-dependent endothelial-derived contracting factor that activates thromboxane-prostanoid receptors, and enhance vascular smooth muscle cells reactivity. ROS can diminish the efficiency with which the kidney uses O(2) for Na(+) transport and thereby diminish the P(O(2)) within the kidney cortex. This may place a break on further ROS generation yet could further enhance vasculopathy and hypertension. There is a tight relationship between oxidative stress in the kidney and the development and maintenance of hypertension.
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Affiliation(s)
- Christopher S Wilcox
- Division of Nephrology and Hypertension, Georgetown University Medical Center, 3800 Reservoir Rd., NW, Washington, DC 20007, USA.
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96
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Shimokawa H, Morikawa K. Hydrogen peroxide is an endothelium-derived hyperpolarizing factor in animals and humans. J Mol Cell Cardiol 2005; 39:725-32. [PMID: 16122755 DOI: 10.1016/j.yjmcc.2005.07.007] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 06/12/2005] [Accepted: 07/11/2005] [Indexed: 10/25/2022]
Abstract
The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several vasodilating substances, including vasodilator prostaglandins, nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF). Since the first report for the existence of EDHF, several substances/mechanisms have been proposed for the nature of EDHF, including epoxyeicosatrienoic acids (metabolites of arachidonic P450 epoxygenase pathway), K ions, and electrical communications through myoendothelial gap junctions. We have recently demonstrated that endothelium-derived hydrogen peroxide (H(2)O(2)) is an EDHF in mouse and human mesenteric arteries and in porcine coronary microvessels. For the synthesis of H(2)O(2) as an EDHF, endothelial Cu,Zn-superoxide dismutase plays an important role in mesenteric arteries of mice and humans. We also have demonstrated that EDHF-mediated responses are attenuated by several arteriosclerotic risk factors, including diabetes mellitus and hyperlipidemia and their combination in particular. Recent studies have indicated that endothelium-derived H(2)O(2) plays an important protective role in coronary autoregulation and myocardial ischemia/reperfusion injury in vivo. Indeed, our H(2)O(2)/EDHF theory demonstrates that endothelium-derived H(2)O(2), another reactive oxygen species in addition to NO, plays an important role as a redox signaling molecule to cause vasodilatation as well as cardioprotection. In this review, we summarize our knowledge on H(2)O(2)/EDHF regarding its identification, mechanisms of synthesis, and clinical implications.
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Affiliation(s)
- Hiroaki Shimokawa
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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97
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Chu Y, Alwahdani A, Iida S, Lund DD, Faraci FM, Heistad DD. Vascular Effects of the Human Extracellular Superoxide Dismutase R213G Variant. Circulation 2005; 112:1047-53. [PMID: 16087794 DOI: 10.1161/circulationaha.104.531251] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Background—
Extracellular superoxide dismutase (ECSOD) is a major extracellular antioxidant enzyme. We have demonstrated that vascular effects of ECSOD require an intact heparin-binding domain. A common genetic variant with a substitution in the heparin-binding domain (ECSOD
R213G
) was reported recently to be associated with ischemic heart disease. The goal of this study was to examine vascular effects of ECSOD
R213G
.
Methods and Results—
A recombinant adenovirus (Ad) that expresses ECSOD
R213G
was constructed. ECSOD
R213G
and ECSOD proteins bound to collagen type I in vitro, but binding to aorta ex vivo was 10-fold greater with ECSOD than ECSOD
R213G
. Three days after intravenous injection of AdECSOD
R213G
or AdECSOD in spontaneously hypertensive rats (SHR), immunostaining demonstrated binding of ECSOD to carotid arteries and kidneys but minimal binding of ECSOD
R213G
. Binding to aorta and carotid artery was 2.5- to 3-fold greater with ECSOD than ECSOD
R213G
by immunoblotting. Arterial pressure was significantly reduced by AdECSOD but not by AdECSOD
R213G
. Responses to acetylcholine and basal levels of nitric oxide in carotid arteries were impaired in SHR compared with normotensive Wistar-Kyoto rats and were improved after AdECSOD but not AdECSOD
R213G
. Levels of superoxide and nitrotyrosine in aorta were higher in SHR than Wistar-Kyoto rats and were greatly reduced after AdECSOD but not AdECSOD
R213G
.
Conclusions—
In contrast to ECSOD, ECSOD
R213G
has no significant protective effect on arterial pressure, vascular function, or vascular levels of oxidative stress in SHR. These findings may provide a mechanistic basis for association studies that suggest that human beings carrying ECSOD
R213G
are predisposed to vascular diseases.
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Affiliation(s)
- Yi Chu
- Cardiovascular Center, Department of Internal Medicine, University of Iowa, Roy J and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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98
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Miller WH, Brosnan MJ, Graham D, Nicol CG, Morecroft I, Channon KM, Danilov SM, Reynolds PN, Baker AH, Dominiczak AF. Targeting endothelial cells with adenovirus expressing nitric oxide synthase prevents elevation of blood pressure in stroke-prone spontaneously hypertensive rats. Mol Ther 2005; 12:321-7. [PMID: 16043100 DOI: 10.1016/j.ymthe.2005.02.025] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Revised: 02/09/2005] [Accepted: 02/23/2005] [Indexed: 11/19/2022] Open
Abstract
Local adenoviral (Ad)-mediated gene transfer to the carotid artery of the stroke-prone spontaneously hypertensive rat (SHRSP) is successful in improving endothelial function. Here we explored the potential of systemic delivery of Ad encoding endothelial nitric oxide synthase (AdeNOS) to prevent elevation of blood pressure in the SHRSP using both nontargeted and vector targeting approaches. Systemic administration of nontargeted AdeNOS failed to modify the rise in blood pressure in SHRSP when administered during the 12th week of age (n = 5, P = 0.088, F = 3.0), an effect likely to result from sequestration of Ad by the liver. Rerouting Ad transduction using a bispecific antibody (anti-ACE/anti-Ad capsid, Fab9B9) that blocks Ad binding to the coxsackie and adenovirus receptor and simultaneously retargets AdeNOS to the angiotensin-converting enzyme resulted in efficient eNOS overexpression in the lung vasculature and a sustained hypotensive effect (n = 5, P = 0.007, F = 7.9). This study highlights the importance of vector targeting to achieve therapeutic gain and represents the first such study in cardiovascular gene therapy.
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Affiliation(s)
- William H Miller
- BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow G11 6NT, Scotland, UK
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99
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Gunnett CA, Lund DD, Faraci FM, Heistad DD. Vascular interleukin-10 protects against LPS-induced vasomotor dysfunction. Am J Physiol Heart Circ Physiol 2005; 289:H624-30. [PMID: 16014616 DOI: 10.1152/ajpheart.01234.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypotheses that 1) systemic IL-10, after adenoviral gene transfer, protects arteries from impaired relaxation produced by LPS; 2) local expression of IL-10 within the arterial wall protects against vasomotor dysfunction after LPS; and 3) IL-10 protects against vascular dysfunction mediated by inducible NO synthase (iNOS) after LPS. In IL-10-deficient (IL-10−/−) and wild-type (WT, IL-10+/+) mice, LPS in vivo impaired relaxation of arteries to acetylcholine and gene transfer of IL-10 improved responses to acetylcholine. Superoxide levels were elevated in arteries after LPS, and increased levels of superoxide were prevented by gene transfer of IL-10. In arteries incubated with a low concentration of LPS in vitro to eliminate systemic effects of LPS and IL-10 from nonvascular sources, responses to acetylcholine were impaired in IL-10-deficient mice and impairment was largely prevented by gene transfer in vitro of IL-10. In arteries from WT mice in vitro, the low concentration of LPS did not impair responses to acetylcholine. Thus IL-10 within the vessel wall protects against LPS-induced dysfunction. In IL-10-deficient mice, aminoguanidine, which inhibits iNOS, protected against vasomotor dysfunction after LPS. In arteries from iNOS-deficient mice, LPS did not impair responses to acetylcholine. These findings suggest that both systemic and local effects of IL-10 provide important protection of arteries against an inflammatory stimulus and that IL-10 decreases iNOS-mediated impairment of vasorelaxation after LPS.
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Affiliation(s)
- Carol A Gunnett
- Department of Internal Medicine, Univ. of Iowa Carver College of Medicine, Iowa City, IA 52242-6778, USA
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100
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Iida S, Chu Y, Francis J, Weiss RM, Gunnett CA, Faraci FM, Heistad DD. Gene transfer of extracellular superoxide dismutase improves endothelial function in rats with heart failure. Am J Physiol Heart Circ Physiol 2005; 289:H525-32. [PMID: 16014615 DOI: 10.1152/ajpheart.00108.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxidative stress is associated with endothelial dysfunction in heart failure. The goals of this study were to determine whether 1) gene transfer of extracellular superoxide dismutase (ecSOD) reduces levels of superoxide and improves endothelial function in the aorta and mesenteric artery in rats with heart failure, and 2) the heparin-binding domain (HBD) of ecSOD, by which ecSOD binds to cells, is required for protective effects of ecSOD. Seven weeks after coronary ligation, in rats with heart failure and sham-operated rats, we injected adenoviral vectors intravenously that express ecSOD, ecSOD with deletion of the HBD (ecSODΔHBD), or a control vector. Four days after injection of viruses, responses to acetylcholine, ADP, and sodium nitroprusside were examined in rings of the aorta and mesenteric artery. ecSOD bound to endothelium and increased SOD activity in the aorta after gene transfer of ecSOD, not ecSODΔHBD. Gene transfer of ecSOD, but not ecSODΔHBD, reduced levels of superoxide and improved relaxation to acetylcholine and ADP in the aorta and mesenteric artery from rats with heart failure. Improvement of relaxation to acetylcholine in the mesenteric artery from rats with heart failure after gene transfer of ecSOD was mediated in part by hydrogen peroxide. The major finding of this study is that the HBD of ecSOD is necessary for protection against endothelial dysfunction in rats with heart failure. We speculate that a common gene variant in the HBD of ecSOD, which is a risk factor for ischemic heart disease, may be a risk factor for vascular maladaptation and endothelial dysfunction in heart failure.
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Affiliation(s)
- Shinichiro Iida
- Cardiovascular Center and Dept. of Internal Medicine, Univ. of Iowa Roy J. and Lucille A Carver, College of Medicine, Iowa City, IA 52242, USA
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