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Schuhmacher S, Foretz M, Knorr M, Jansen T, Hortmann M, Wenzel P, Oelze M, Kleschyov AL, Daiber A, Keaney JF, Wegener G, Lackner K, Münzel T, Viollet B, Schulz E. α1AMP-activated protein kinase preserves endothelial function during chronic angiotensin II treatment by limiting Nox2 upregulation. Arterioscler Thromb Vasc Biol 2011; 31:560-6. [PMID: 21205985 DOI: 10.1161/atvbaha.110.219543] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Besides its well-described metabolic effects, vascular AMP-activated protein kinase (AMPK) can activate endothelial NO synthase, promotes angiogenesis, and limits endothelial cell apoptosis. The current study was designed to study the effects of α1AMPK deletion during vascular disease in vivo. METHODS AND RESULTS Chronic angiotensin II infusion at low subpressor doses caused a mild endothelial dysfunction that was significantly aggravated in α1AMPK-knockout mice. Unexpectedly, this endothelial dysfunction was not associated with decreased NO content, because NO levels measured by serum nitrite or electron paramagnetic resonance were even increased. However, because of parallel superoxide production, NO was consumed under production of peroxynitrite in angiotensin II-treated α1AMPK-knockout mice, associated with NADPH oxidase activation and Nox2 upregulation. As Nox2 is also a component of phagocyte NADPH oxidases, we found a vascular upregulation of several proinflammatory markers, including inducible NO synthase, vascular cell adhesion molecule-1, and cyclooxygenase-2. Cotreatment with the NADPH oxidase inhibitor apocynin was able to prevent vascular inflammation and also partially restored endothelial function in α1AMPK-knockout mice. CONCLUSIONS Our data indicate that in vivo α1AMPK deletion leads to Nox2 upregulation, resulting in endothelial dysfunction and vascular inflammation. This implicates basal AMPK activity as a protective, redox-regulating element in vascular homeostasis.
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Affiliation(s)
- Swenja Schuhmacher
- Department of Cardiology, II Medizinische Klinik und Poliklinik, Universitätsmedizin Mainz, Mainz, Germany
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High salt intake delayed angiotensin II-induced hypertension in mice with a genetic variant of NADPH oxidase. Am J Hypertens 2011; 24:114-8. [PMID: 20706193 DOI: 10.1038/ajh.2010.173] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND gp91(PHOX), a catalytic subunit of NAD(P)H oxidase, is involved in angiotensin II (Ang II)-induced superoxide (O₂⁻) generation. This study was designed to examine the hypothesis that an enhancement in O₂⁻ generation due to elevated Ang II induces salt-sensitivity, which contributes to the development of hypertension. METHODS Assessment of blood pressure and renal excretory responses to Ang II infusion (2.2 ng·min/g) for 2 weeks via osmotic minipump was made in knockout (KO; n = 20) mice lacking the gene for gp91(PHOX) which were fed on either normal-salt (NS; 0.04% NaCl) or high-salt (HS, 4% NaCl) diet and compared these responses with those in wild-type (WT; n = 23) mice. RESULTS Ang II induced increase in systolic blood pressure (SBP) was started within the 4th day in all groups except in HS fed KO mice in which SBP increased after the 10(th) day of Ang II infusion. The increases in SBP were lower in KO than WT mice at the end of 2-week infusion period. In Ang II + HS fed KO mice, the urinary excretion rate of nitrite/nitrate (U(NOx)V) markedly increased but 8-isoprostane excretion rate remained unchanged. These findings indicate that an increase in nitric oxide (NO) with a lack of O₂⁻ formation was involved in the delayed hypertension in Ang II + HS fed KO mice. CONCLUSION These data suggest that an enhanced O₂⁻ activity and its interaction with NO contribute to the early developmental phase of Ang II-induced salt-sensitive hypertension.American Journal of Hypertension (2011). doi:10.1038/ajh.2010.173.
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103
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Leonarduzzi G, Sottero B, Poli G. Targeting tissue oxidative damage by means of cell signaling modulators: The antioxidant concept revisited. Pharmacol Ther 2010; 128:336-74. [DOI: 10.1016/j.pharmthera.2010.08.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 08/02/2010] [Indexed: 12/25/2022]
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104
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Bachschmid MM, Xu S, Maitland-Toolan KA, Ho YS, Cohen RA, Matsui R. Attenuated cardiovascular hypertrophy and oxidant generation in response to angiotensin II infusion in glutaredoxin-1 knockout mice. Free Radic Biol Med 2010; 49:1221-9. [PMID: 20638471 PMCID: PMC2930025 DOI: 10.1016/j.freeradbiomed.2010.07.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 07/01/2010] [Accepted: 07/09/2010] [Indexed: 12/29/2022]
Abstract
Glutaredoxin-1 (Glrx) is a thioltransferase that regulates protein S-glutathiolation. To elucidate the role of endogenous Glrx in cardiovascular disease, Glrx knockout (KO) mice were infused with angiotensin II (Ang II) for 6days. After Ang II infusion, body weight and blood pressure were similar between WT and Glrx KO mice. However, compared to WT mice, Glrx KO mice demonstrated (1) less cardiac and aortic medial hypertrophy, (2) less oxidant generation in aorta as assessed by dihydroethidium staining and nitrotyrosine, (3) decreased phosphorylation of Akt in the heart, and (4) less expression of inducible NOS in aorta and heart. In cultured embryonic fibroblasts from Glrx KO mice, S-glutathiolation of actin was enhanced and actin depolymerization was impaired after hydrogen peroxide stimulation compared with WT cells. Furthermore, oxidant generation in phorbol ester-stimulated fibroblasts and RAW 264.7 macrophage-like cells was lower with Glrx siRNA knockdown. These data indicate that Ang II-induced oxidant production and hypertrophic responses were attenuated in Glrx KO mice, which may result from impaired NADPH oxidase activation.
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Affiliation(s)
- Markus M Bachschmid
- Vascular Biology Unit, Department of Medicine, Boston University, Boston, MA 02118, USA
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105
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Abstract
Vascular disease in hypertension and diabetes is associated with increased oxidants. The oxidants arise from NADPH oxidase, xanthine oxidase, and mitochondria. Superoxide anion and hydrogen peroxide are produced by both leukocytes and vascular cells. Nitric oxide is produced in excess by inducible nitric oxide synthase, and the potent oxidant, peroxynitrite, is formed from superoxide and nitric oxide. The damage to proteins caused by oxidants is selective, affecting specific oxidant-sensitive amino acid residues. With some important vascular proteins, for example, endothelial nitric oxide synthase, prostacycline synthase, and superoxide dismutase, oxidation of a single susceptible amino acid inactivates the enzyme. The beneficial effects of antioxidants, at least in animal models of hypertension and diabetes, can in part be ascribed to protection of these and other proteins. Mutant proteins lacking their reactive constituent can recapitulate some disease phenotypes suggesting a pathogenic role of the oxidation. Thus, many of the shared functional abnormalities of hypertensive and diabetic blood vessels may be caused by oxidants. Although studies using antioxidants have failed in patients, the successful treatment of vascular disease with HMG-CoA reductase inhibitors, thromboxane A2 antagonists, and polyphenols may depend on their anti-inflammatory effects and ability to decrease production of damaging oxidants.
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Between nitros(yl)ation and nitration: Regulation of thioredoxin-1 in myocardial ischemia/reperfusion injury. J Mol Cell Cardiol 2010; 49:343-6. [DOI: 10.1016/j.yjmcc.2010.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 05/30/2010] [Accepted: 06/01/2010] [Indexed: 11/19/2022]
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107
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Kwan CY, Hsieh WT, To PNH, Wang HD. New perspectives on vascular wall signaling: role of perivascular adipocytes and fibroblasts. Acta Pharmacol Sin 2010; 31:1022-5. [PMID: 20711223 PMCID: PMC4002319 DOI: 10.1038/aps.2010.148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 07/27/2010] [Indexed: 11/09/2022] Open
Abstract
This communication represents personal perspectives of recent development in the newly evolved areas in vascular signaling mechanisms at the anatomical level of vascular walls from outside in, that is, from perivascular adventitial side to effectuate the control of vascular reactivity. Since half a century ago, the focus of interest in vascular biology has been confined primarily to the study of the excitation-contraction coupling of vascular smooth muscle (VSM) as well as neuroeffector mechanisms. During the past 3 decades, considerable advancement in the understanding of vascular signaling has been made via the discovery of endothelium-derived relaxation factors (EDRF), endothelium-derived hyperpolarizing factors (EDHF) and endothelium-derived contracting factors (EDCF). The discovery of nitric oxide (NO) as a major cellular messenger has also helped open up another huge area of research in oxidative stress and vascular diseases. In the past decade, concepts on vascular wall signaling have been extended from vascular endothelial cells and then translated to the other seemingly inert cellular components, such as perivascular adipocytes and adventitial fibroblasts. Growing body of evidences show that these cellularities contribute to both functional as well as structural integrity in vasculature with significant pathophysiological implications.
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Affiliation(s)
- Chiu-Yin Kwan
- Graduate Institute of Basic Medical Sciences, China Medical University and Hospitals, Taichung, Taiwan, China.
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Chen CCA, Pedraza PL, Hao S, Stier CT, Ferreri NR. TNFR1-deficient mice display altered blood pressure and renal responses to ANG II infusion. Am J Physiol Renal Physiol 2010; 299:F1141-50. [PMID: 20739394 DOI: 10.1152/ajprenal.00344.2010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The hypothesis that TNF receptor 1-deficient (TNFR1(-/-)) mice display blood pressure (BP) and renal functional responses that differ from wild-type (WT) mice was tested in an angiotensin II (ANG II)-dependent model of hypertension. Basal systolic BP (SBP), mean arterial pressure, diastolic BP, heart rate (HR), and pulse pressure were similar in WT and TNFR1(-/-) mice. Infusion of ANG II for 7 days elevated SBP to a greater extent in TNFR1(-/-) compared with WT mice; pulse pressure was also elevated in TNFR1(-/-). HR decreased in TNFR1(-/-) mice infused with ANG II, an effect prominent on day 1. Basal urinary albumin excretion was similar in WT and TNFR1(-/-) mice but was higher in TNFR1(-/-) in response to ANG II infusion. Water intake and urine volume were increased by ANG II infusion; this increase was higher in TNFR1(-/-) vs. WT mice, whereas body weight and food intake were unaffected. Baseline creatinine clearance (Ccr), urinary sodium excretion, and fractional excretion of sodium (FE(Na)%) were similar in vehicle-treated WT and TNFR1(-/-) mice. ANG II infusion for 7 days increased Ccr and filtered load of sodium in TNFR1(-/-) but not WT mice, whereas it elicited an increase in FE(Na)% and urinary sodium excretion in WT but not TNFR1(-/-) mice. ANG II also inhibited renal TNFR1 mRNA accumulation while increasing that of TNFR2. These findings indicate deletion of TNFR1 is associated with an exacerbated SBP response, decrease in HR, and altered renal function in ANG II-dependent hypertension.
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Rivera J, Sobey CG, Walduck AK, Drummond GR. Nox isoforms in vascular pathophysiology: insights from transgenic and knockout mouse models. Redox Rep 2010; 15:50-63. [PMID: 20500986 DOI: 10.1179/174329210x12650506623401] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Elevated reactive oxygen species (ROS) formation in the vascular wall is a key feature of cardiovascular diseases and a likely contributor to oxidative stress, endothelial dysfunction and vascular inflammation. The NADPH oxidases are a family of ROS generating enzymes, of which four members (Nox1, Nox2, Nox4 and Nox5) are expressed in blood vessels. Numerous studies have demonstrated that expression and activity of at least two isoforms of NADPH oxidase - Nox1 and Nox2 - are up-regulated in animal models of hypertension, diabetes and atherosclerosis. However, these observations are merely suggestive of a role for NADPH oxidases in vessel pathology and by no means establish cause and effect. Furthermore, questions surrounding the specificity of current pharmacological inhibitors of NADPH oxidase mean that findings obtained with these compounds must be viewed with caution. Here, we review the literature on studies utilising genetically-modified mouse strains to investigate the roles of NADPH oxidases in experimental models of vascular disease. While several studies on transgenic over-expressing or knockout mice support roles for Nox1- and/or Nox2-containing oxidases as sources of excessive vascular ROS production and causes of endothelial dysfunction in hypertension, atherosclerosis and diabetes, there are still no published reports on the effects of genetic modification of Nox4 or Nox5 in vascular or indeed any other contexts. Further understanding of the roles of specific isoforms of NADPH oxidase in vascular (patho)physiology should provide direction for future programs aimed at developing selective inhibitors of these enzymes as novel therapeutics in cardiovascular disease.
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Affiliation(s)
- Jennifer Rivera
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia
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Wang W, Pang L, Palade P. Angiotensin II upregulates Ca(V)1.2 protein expression in cultured arteries via endothelial H(2)O(2) production. J Vasc Res 2010; 48:67-78. [PMID: 20639649 DOI: 10.1159/000318776] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Accepted: 03/15/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We previously reported that angiotensin II caused an endothelial-dependent increase in L-type voltage-dependent Ca(2+) channel (Ca(V)1.2) in cultured arteries, but the signaling pathways are not clear. METHODS Endothelial damage was generated by brief intra-arterial perfusion with 0.3% CHAPS. Ca(V)1.2 expression, function and H(2)O(2) were measured by Western blot, tension recording and Amplex Red H(2)O(2) assay kit, respectively. RESULTS Angiotensin II dose-dependently upregulated Ca(V)1.2 expression in endothelium-intact arteries. The angiotensin II upregulation of Ca(V)1.2 expression in endothelium-intact arteries was blocked by NAD(P)H oxidase inhibitor diphenyleneiodonium (DPI), apocynin, a more specific NAD(P)H oxidase inhibitor gp91ds-tat and also by catalase. H(2)O(2) similarly upregulated Ca(V)1.2 expression in endothelium-intact and endothelium-damaged arteries, and the latter effect was also blocked by DPI and apocynin. Angiotensin II increased H(2)O(2) production by endothelium-intact but not by endothelium-damaged arteries, and this effect was blocked by apocynin, catalase and gp91ds-tat. The upregulation of Ca(V)1.2 by angiotensin II and H(2)O(2) is accompanied by an increased tension response to KCl and the Ca(2+) channel activator FPL 64176, and this effect was also attenuated by gp91ds-tat. CONCLUSION These results suggest that angiotensin II stimulates endothelial NAD(P)H oxidase-produced H(2)O(2,) which may additionally act through vascular smooth muscle NAD(P)H oxidase, to upregulate vascular Ca(V)1.2 protein.
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Affiliation(s)
- Wenze Wang
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Ark 72205, USA. wwang @ uams.edu
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111
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Lijnen PJ, van Pelt JF, Fagard RH. Stimulation of reactive oxygen species and collagen synthesis by angiotensin II in cardiac fibroblasts. Cardiovasc Ther 2010; 30:e1-8. [PMID: 20626399 DOI: 10.1111/j.1755-5922.2010.00205.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Superoxide anion generated by NAD(P)H-oxidase has an important role in the pathogenesis of cardiovascular diseases and scavenging superoxide anion can be considered as a reasonable therapeutic strategy. In hypertensive heart diseases there is a mutual reinforcement of reactive oxygen species (ROS) and angiotensin II (ANG II). ANG II increases the NAD(P)H-dependent superoxide anion production and the intracellular generation of ROS in cardiac fibroblasts and apocynin, a membrane NAD(P)H oxidase inhibitor, abrogates this rise. ANG II also stimulates the collagen production, the collagen I and III content and mRNA expression in cardiac fibroblasts and apocynin abolishes this induction. In this review we demonstrate that scavenging superoxide anion by tempol or EUK-8 or administration of PEG-superoxide dismutase (SOD) inhibits collagen production in cardiac fibroblasts. On the contrary increasing superoxide anion formation by inhibition of SOD stimulates collagen production. A vital role of SOD and the generated ROS can be suggested in the regulation and organization of collagen in cardiac fibroblasts. Specific pharmacological intervention with SOD mimetics can probably be an alternative approach for reducing myocardial fibrosis.
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Affiliation(s)
- Paul J Lijnen
- Hypertension and Cardiovascular Rehabilitation Unit, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, Leuven, Belgium.
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Bukowska A, Röcken C, Erxleben M, Röhl FW, Hammwöhner M, Huth C, Ebert MP, Lendeckel U, Goette A. Atrial expression of endothelial nitric oxide synthase in patients with and without atrial fibrillation. Cardiovasc Pathol 2010; 19:e51-60. [DOI: 10.1016/j.carpath.2008.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 12/12/2008] [Accepted: 12/24/2008] [Indexed: 10/21/2022] Open
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Zhao TC, Zhang LX, Cheng G, Liu JT. gp-91 mediates histone deacetylase inhibition-induced cardioprotection. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:872-80. [PMID: 20433879 DOI: 10.1016/j.bbamcr.2010.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 04/01/2010] [Accepted: 04/19/2010] [Indexed: 01/05/2023]
Abstract
We have recently shown that the inhibition of histone deacetylases (HDAC) protects the heart against ischemia and reperfusion (I/R) injury. The mechanism by which HDAC inhibition induces cardioprotection remains unknown. We sought to investigate whether the genetic disruption of gp-91, a subunit of NADPH-oxidase, would mitigate cardioprotection of HDAC inhibition. Wild-type and gp-91(-)(/-) mice were treated with a potent inhibitor of HDACs, trichostatin A (TSA, 0.1 mg/kg, i.p.). Twenty-four hours later, the perfused hearts were subjected to 30 min of ischemia and 30 min of reperfusion. HDAC inhibition in wild-type mice produced marked improvements in ventricular functional recovery and the reduction of infarct size. TSA-induced cardioprotection was eliminated with genetic deletion of gp91. Notably, Western blot and immunostaining displayed a significant increase in gp-91 in myocardium following HDAC inhibition, which resulted in a mildly subsequent increase in the production of reactive oxygen species (ROS). The pre-treatment of H9c2 cardiomyoblasts with TSA (50 nmol/l) decreased cell necrosis and increased viability in response to simulated ischemia (SI), which was abrogated by the transfection of cells with gp-91 siRNA, but not by scrambled siRNA. Furthermore, treatment of PLB-985 gp91(+/+) cells with TSA increased the resistance to SI, which also diminished with genetic disruption of gp91 in gp91(phox)-deficient PLB-985 cells. TSA treatment inhibited the increased active caspase-3 in H9c2 cardiomyoblasts and PLB-985 gp91(+/+) cells exposed to SI, which were prevented by knockdown of gp-91 by siRNA. These results suggest that a cascade consisting of gp-91 and HDAC inhibition plays an essential role in orchestrating the cardioprotective effect.
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Affiliation(s)
- Ting C Zhao
- Department of Surgery, Roger William Medical Center, Boston University Medical School, Providence, RI 02908, USA.
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Sakuta T, Morita Y, Satoh M, Fox DA, Kashihara N. Involvement of the renin-angiotensin system in the development of vascular damage in a rat model of arthritis: Effect of angiotensin receptor blockers. ACTA ACUST UNITED AC 2010; 62:1319-28. [DOI: 10.1002/art.27384] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Crispo S, De Gennaro S, Buono F, Crispo A, Meccariello A, Morisco C, Trimarco B. Menopause Increases the Risk of Carotid Atherosclerosis in Essential Hypertension. High Blood Press Cardiovasc Prev 2010. [DOI: 10.2165/11311740-000000000-00000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Wang HD, Rätsep MT, Chapman A, Boyd R. Adventitial fibroblasts in vascular structure and function: the role of oxidative stress and beyondThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease. Can J Physiol Pharmacol 2010; 88:177-86. [DOI: 10.1139/y10-015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The vascular adventitia, defined as the area between the external elastic lamina and the outermost edge of the blood vessel, is composed primarily of fibroblasts and for years was thought to be merely a passive structural support for the blood vessel. Consequently, studies pertaining to the role of the adventitia in regulating vascular function have been far outnumbered by those regarding the vascular endothelium. However, recent work has begun to reveal the dynamic properties of the adventitia. It was therefore the aim of this review to provide an overview of the existing knowledge demonstrating the role of the adventitia in regulating vessel structure and function. The main topics covered in this review include the cellular composition of the adventitia and the role of the adventitia in vascular oxidative stress, vasomotor responses, extracellular matrix protein expression, growth factor expression, and endothelin-1 (ET-1) expression. Recent evidence suggests that the adventitia is a major producer of vascular reactive oxygen species. It displays a distinct response to injury, hypoxia, and pulmonary hypertension, mediating vascular remodelling, repair, and extracellular matrix deposition. It may also play a role in regulating vascular tone. More recently, it has been reported that adventitial fibroblasts can produce ET-1 after Ang II treatment. Additionally, emerging evidence suggests that the adventitia may be a potent source of vasoactive hormones such as growth factors and ET-1, which may regulate vascular structure and function via autocrine or paracrine signalling mechanisms. Despite these findings, many important questions regarding the role of the vascular adventitia remain unanswered, suggesting the need for further research to determine its exact function in health and disease.
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Affiliation(s)
- Hui Di Wang
- Department of Community Health Sciences, Faculty of Applied Heath Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Matthew T. Rätsep
- Department of Community Health Sciences, Faculty of Applied Heath Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Alexander Chapman
- Department of Community Health Sciences, Faculty of Applied Heath Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Ryan Boyd
- Department of Community Health Sciences, Faculty of Applied Heath Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
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Abstract
Vascular smooth muscle cell migration is important during vascular development and contributes to lesion formation in the adult vasculature. The mechanisms regulating migration of this cell type are therefore of great interest. Recent work has shown that reactive oxygen species (ROS) derived from NADPH oxidases are important mediators of promigratory signaling pathways. ROS regulate the intracellular signals responsible for lamellipodia formation, actin cytoskeleton remodeling, focal adhesion turnover, and contraction of the cell body. In addition, they contribute to matrix remodeling, a critical step to initiate and support vascular smooth muscle cell motility. Despite these recent advances in our understanding of the redox mechanisms that contribute to migration, additional work is needed to evaluate fully the potential of ROS-sensitive molecular signals as therapeutic targets to prevent inappropriate smooth muscle cell migration.
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Rancourt ME, Rodrigue ME, Agharazii M, Lariviere R, Lebel M. Role of oxidative stress in erythropoietin-induced hypertension in uremic rats. Am J Hypertens 2010; 23:314-20. [PMID: 20019674 DOI: 10.1038/ajh.2009.242] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Erythropoietin (EPO) administration in uremic rats leads to an increase in blood pressure (BP). Because chronic renal failure has been associated with oxidative stress, we hypothesize that EPO treatment could accentuate this condition and contribute to hypertension. The present study was designed to investigate the role of reactive oxygen species in EPO-induced hypertension and the effect of tempol, a superoxide dismutase-mimetic. METHODS Renal failure was induced by a two-stage 5/6 nephrectomy followed by a 3-week stabilization period. Uremic rats were divided into four groups and received for 4 weeks: vehicle; EPO (100 U/kg, subcutaneously, three times per week); vehicle + tempol (1 mmol/l in drinking water); and EPO + tempol. Systolic BP and biochemical parameters were assessed before and at the end of the treatment. Renal histology, creatinine clearance rate, endothelin-1 (ET-1) concentrations and superoxide anion production were assessed at the end of the study. RESULTS The uremic rats developed anemia and hypertension. ET-1 concentrations and superoxide anion production were increased. EPO administration corrected anemia, but accentuated hypertension and renal injuries such as glomerulosclerosis, interstitial fibrosis, and inflammation. EPO therapy further increased tissue levels of ET-1 and superoxide anion production. Tempol treatment improved hypertension and renal injury, and reduced ET-1 concentrations and superoxide anion production. CONCLUSION Oxidative stress contributes to the development of hypertension and to the progression of renal injuries in uremic rats. EPO administration further increases oxidative stress, which might partly account for the accentuation of hypertension and renal injury.
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Cohen RA, Feletou M, Vanhoutte PM, Verbeuren TJ. TP receptors and oxidative stress hand in hand from endothelial dysfunction to atherosclerosis. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2010; 60:85-106. [PMID: 21081216 PMCID: PMC3004095 DOI: 10.1016/b978-0-12-385061-4.00004-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Thromboxane A(2) and the activation of TP receptors that it causes play an important role in platelet aggregation and therefore in thrombosis. However, TP receptors are also involved in the pathologies of the vascular wall including impaired endothelium-dependent vasodilation, increased oxidant generation, and increased expression of adhesion molecules. The beneficial effects of TP antagonists on the vascular wall attenuate these features of vascular disease. They are not shared by aspirin. In fact, TP antagonists are active in patients treated with aspirin, indicating that their potential beneficial effects are mediated by mechanisms different from the antithrombotic actions of aspirin. Our studies have demonstrated the vascular benefits of TP antagonists in experimental animals, particularly in models of diabetes mellitus, in which elevated levels of eicosanoids play a role not only in vascular pathologies but also in those of the kidney and other tissues. They suggest that TP blockade protects against fundamental and widespread tissular dysfunction associated with metabolic disease including hyperlipidemia and hyperglycemia. TP receptor antagonists represent a promising avenue for the prevention of vascular disease in part because of these pleiotropic actions that extend beyond their antithrombotic properties.
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Affiliation(s)
- Richard A. Cohen
- Vascular Biology Unit, Whitaker Cardiovascular Institute, Boston University School of Medicine
| | - Michel Feletou
- Department of Angiology, Institut de Recherches Servier, Suresnes, France
| | - Paul M. Vanhoutte
- Department Pharmacology and Pharmacy, Li Ka Shing Faculty Medicine, University of Hong Kong, Hong Kong, China and Department BIN Fusion Technology, Chonbuk National University, Jeonju, Korea
| | - Tony J. Verbeuren
- Department of Angiology, Institut de Recherches Servier, Suresnes, France,Correspondence to: Dr Tony J. Verbeuren, Department of Angiology, Institut de Recherches Servier, 11 rue des Moulineaux, Suresnes, France., Tel:
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Ardanaz N, Yang XP, Cifuentes ME, Haurani MJ, Jackson KW, Liao TD, Carretero OA, Pagano PJ. Lack of glutathione peroxidase 1 accelerates cardiac-specific hypertrophy and dysfunction in angiotensin II hypertension. Hypertension 2009; 55:116-23. [PMID: 19917877 DOI: 10.1161/hypertensionaha.109.135715] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Glutathione peroxidase 1 (Gpx1) plays an important role in cellular defense by converting hydrogen peroxide and organic hydroperoxides to nonreactive products, and Gpx1(-/-) mice, which are characterized by reduced tissue glutathione peroxidase activity, are known to exhibit enhanced oxidative stress. Peroxides participate in tissue injury, as well as the hypertrophy of cultured cells, yet the role of Gpx1 to prevent end organ damage in cardiovascular tissue is not clear. We postulated that Gpx1 deletion would potentiate both aortic and cardiac hypertrophy, as well as mean arterial blood pressure, in response to angiotensin II (AngII). Our results show that short-term AngII markedly increased left ventricular mass, myocyte cross-sectional area, and interventricular septum thickness and decreased shortening fraction in Gpx1(-/-) mice as compared with wild-type animals. On the other hand, AngII resulted in a similar increase in mean arterial blood pressure in wild-type and Gpx1(-/-) mice. Collagen deposition increased in response to AngII, but no differences were found between strains. Vascular hypertrophy increased to the same extent in Gpx1(-/-) and wild-type mice. Collectively, our results indicate that Gpx1 deficiency accelerates cardiac hypertrophy and dysfunction but has no effect on vascular hypertrophy and mean arterial blood pressure and suggest a major role for Gpx1 in cardiac dysfunction in AngII-dependent hypertension.
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Affiliation(s)
- Noelia Ardanaz
- Department of Pharmacology and Chemical Biology and Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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122
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Hanif K, Bid HK, Konwar R. Reinventing the ACE inhibitors: some old and new implications of ACE inhibition. Hypertens Res 2009; 33:11-21. [PMID: 19911001 DOI: 10.1038/hr.2009.184] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since their inception, angiotensin-converting enzyme (ACE) inhibitors have been used as first-line therapy for the treatment of cardiovascular and renal diseases. They restore the balance between the vasoconstrictive salt-retentive and hypertrophy-causing peptide angiotensin II (Ang II) and bradykinin, a vasodilatory and natriuretic peptide. As ACE is a promiscuous enzyme, ACE inhibitors alter the metabolism of a number of other vasoactive substances. ACE inhibitors decrease systemic vascular resistance without increasing heart rate and promote natriuresis. They have been proven effective in the treatment of hypertension, and reduce mortality in congestive heart failure and left ventricular dysfunction after myocardial infarction. They inhibit ischemic events and stabilize plaques. Furthermore, they delay the progression of diabetic nephropathy and neuropathy and act as antioxidants. Ongoing studies have elucidated protective roles for them in both memory-related disorders and cancer. Lastly, N- and C-domain selective ACE inhibitors have led to new uses for ACE inhibitors.
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Affiliation(s)
- Kashif Hanif
- Division of Pharmacology, Central Drug Research Institute (CSIR), Lucknow, Uttar Pradesh, India.
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123
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Lassègue B, Griendling KK. NADPH oxidases: functions and pathologies in the vasculature. Arterioscler Thromb Vasc Biol 2009; 30:653-61. [PMID: 19910640 DOI: 10.1161/atvbaha.108.181610] [Citation(s) in RCA: 445] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species are ubiquitous signaling molecules in biological systems. Four members of the NADPH oxidase (Nox) enzyme family are important sources of reactive oxygen species in the vasculature: Nox1, Nox2, Nox4, and Nox5. Signaling cascades triggered by stresses, hormones, vasoactive agents, and cytokines control the expression and activity of these enzymes and of their regulatory subunits, among which p22phox, p47phox, Noxa1, and p67phox are present in blood vessels. Vascular Nox enzymes are also regulated by Rac, ClC-3, Poldip2, and protein disulfide isomerase. Multiple Nox subtypes, simultaneously present in different subcellular compartments, produce specific amounts of superoxide, some of which is rapidly converted to hydrogen peroxide. The identity and location of these reactive oxygen species, and of the enzymes that degrade them, determine their downstream signaling pathways. Nox enzymes participate in a broad array of cellular functions, including differentiation, fibrosis, growth, proliferation, apoptosis, cytoskeletal regulation, migration, and contraction. They are involved in vascular pathologies such as hypertension, restenosis, inflammation, atherosclerosis, and diabetes. As our understanding of the regulation of these oxidases progresses, so will our ability to alter their functions and associated pathologies.
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Affiliation(s)
- Bernard Lassègue
- Emory University School of Medicine, Division of Cardiology, 1639 Pierce Drive, WMB 319, Atlanta, GA 30322, USA
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124
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Csányi G, Taylor WR, Pagano PJ. NOX and inflammation in the vascular adventitia. Free Radic Biol Med 2009; 47:1254-66. [PMID: 19628034 PMCID: PMC3061339 DOI: 10.1016/j.freeradbiomed.2009.07.022] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 07/10/2009] [Accepted: 07/14/2009] [Indexed: 02/07/2023]
Abstract
Vascular inflammation has traditionally been thought to be initiated at the luminal surface and progress through the media toward the adventitial layer. In recent years, however, evidence has emerged suggesting that the vascular adventitia is activated early in a variety of cardiovascular diseases and that it plays an important role in the initiation and progression of vascular inflammation. Adventitial fibroblasts have been shown to produce substantial amounts of NAD(P)H oxidase-derived reactive oxygen species (ROS) in response to vascular injury. Additionally, inflammatory cytokines, lipids, and various hormones, implicated in fibroblast proliferation and migration, lead to recruitment of inflammatory cells to the adventitial layer and impairment of endothelium-dependent relaxation. Early in the development of vascular disease, there is clear evidence for progression toward a denser vasa vasorum which delivers oxygen and nutrients to an increasingly hypoxic and nutrient-deficient media. This expanded vascularization appears to provide enhanced delivery of inflammatory cells to the adventitia and outer media. Combined adventitial fibroblast and inflammatory cell-derived ROS therefore are expected to synergize their local effect on adventitial parenchymal cells, leading to further cytokine release and a feed-forward propagation of adventitial ROS production. In fact, data from our laboratory and others suggest a broader paracrine positive feedback role for adventitia-derived ROS in medial smooth muscle cell hypertrophy and neointimal hyperplasia. A likely candidate responsible for the adventitia-derived paracrine signaling across the vessel wall is the superoxide anion metabolite hydrogen peroxide, which is highly stable, cell permeant, and capable of activating downstream signaling mechanisms in smooth muscle cells, leading to phenotypic modulation of smooth muscle cells. This review addresses the role of adventitial NAD(P)H oxidase-derived ROS from a nontraditional, perivascular vantage of promoting vascular inflammation and will discuss how ROS derived from adventitial NAD(P)H oxidases may be a catalyst for vascular remodeling and dysfunction.
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Affiliation(s)
- Gábor Csányi
- Department of Pharmacology & Chemical Biology and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
| | - W. Robert Taylor
- Departments of Medicine and Biomedical Engineering, Emory University and the Atlanta VA Medical Center, Atlanta, GA
| | - Patrick J. Pagano
- Department of Pharmacology & Chemical Biology and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA
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125
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Yao B, Harris RC, Zhang MZ. Intrarenal dopamine attenuates deoxycorticosterone acetate/high salt-induced blood pressure elevation in part through activation of a medullary cyclooxygenase 2 pathway. Hypertension 2009; 54:1077-83. [PMID: 19770404 DOI: 10.1161/hypertensionaha.109.137174] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Locally produced dopamine in the renal proximal tubule inhibits salt and fluid reabsorption, and a dysfunctional intrarenal dopaminergic system has been reported in essential hypertension and experimental hypertension models. Using catechol-O-methyl-transferase knockout (COMT(-/-)) mice, which have increased renal dopamine because of deletion of the major renal dopamine-metabolizing enzyme, we investigated the effect of intrarenal dopamine on the development of hypertension in the deoxycorticosterone acetate/high-salt (DOCA/HS) model. DOCA/HS led to significant increases in systolic blood pressure in wild-type mice (from 115+/-2 to 153+/-4 mm Hg), which was significantly attenuated in COMT(-/-) mice (from 114+/-2 to 135+/-3 mm Hg). In DOCA/HS COMT(-/-) mice, the D1-like receptor antagonist SCH-23390 increased systolic blood pressure (156+/-2 mm Hg). DOCA/HS COMT(-/-) mice also exhibited more urinary sodium excretion (COMT(-/-) versus wild-type: 3038+/-430 versus 659+/-102 micromol/L per 24 hours; P<0.01). Furthermore, DOCA/HS-induced renal oxidative stress was significantly attenuated in COMT(-/-) mice. COX-2-derived prostaglandins in the renal medulla promote sodium excretion, and dopamine stimulates medullary prostaglandin production. Renal medullary COX-2 expression and urinary prostaglandin E2 excretion were significantly higher in COMT(-/-) than in wild-type mice after DOCA/HS treatment. In DOCA/HS-treated COMT(-/-) mice, the COX-2 inhibitor SC-58236 reduced urinary sodium and prostaglandin E(2) excretion and increased systolic blood pressure (153+/-2 mm Hg). These studies indicate that an activated renal dopaminergic system attenuates the development of hypertension, at least in large part through activating medullary COX-2 expression/activity, and also decreases oxidative stress resulting from DOCA/HS.
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Affiliation(s)
- Bing Yao
- Nashville Veterans' Administration Hospital and Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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126
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Wang Y, Sun Z. Klotho gene delivery prevents the progression of spontaneous hypertension and renal damage. Hypertension 2009; 54:810-7. [PMID: 19635988 DOI: 10.1161/hypertensionaha.109.134320] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Klotho is a recently discovered antiaging gene. The objective of this study was to test the hypothesis that klotho gene delivery attenuates the progression of spontaneous hypertension and renal damage in spontaneous hypertensive rats (SHRs). An adeno-associated virus (AAV) carrying mouse klotho full-length cDNA (AAV.mKL) was constructed for in vivo expression of klotho. Four groups of male SHRs and 1 group of sex- and age-matched Wistar-Kyoto rats (5 rats per group) were used. Blood pressure was measured twice in all of the animals before gene delivery. Four groups of SHRs received an IV injection of AAV.mKL, AAV.LacZ, AAV.GFP, and PBS, respectively. The Wistar-Kyoto group received PBS and served as a control. AAV.mKL stopped the further increase in blood pressure in SHRs, whereas blood pressures continued to increase in other SHR groups. One single dose of AAV.mKL prevented the progression of spontaneous hypertension for at least 12 weeks (length of the study). Klotho expression and production were suppressed in SHRs, which were reverted by AAV.mKL. AAV.mKL increased plasma interleukin 10 levels but decreased Nox2 expression, NADPH oxidase activity, and superoxide production in kidneys and aortas in SHRs. AAV.mKL abolished renal tubular atrophy and dilation, tubular deposition of proteinaceous material, glomerular collapse, and collagen deposition seen in SHRs, indicating that klotho gene delivery attenuated renal damage. Therefore, the suppressed klotho expression may play a role in the progression of spontaneous hypertension and renal damage in SHRs. AAV delivery of klotho may offer a new approach for the long-term control of hypertension and for renoprotection.
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Affiliation(s)
- Yuhong Wang
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, 940 S.L. Young Blvd., Oklahoma City, OK 73126-0901, USA
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127
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Abstract
The endothelium is an important component of vascular homeostasis that is a target for injury in the setting of vascular disease. One means of promoting a maladaptive endothelial cell phenotype such as that seen in atherosclerosis is excess oxidative stress. Although this term once was almost exclusively used to describe low-density lipoprotein (LDL) and lipid oxidation in the vasculature, we now understand that the intracellular oxidant milieu is an important modulator of vascular cell function. Indeed, considerable data indicate that reactive oxygen species (ROS) are an important means of cellular signaling, although the precise mechanisms whereby ROS accomplish this are still under investigation. In this review, the data linking ROS to kinase activation and cell signaling in the endothelium is discussed, with a particular emphasis on the roles of protein thiol modification.
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Affiliation(s)
- Kai Chen
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts, USA
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128
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Selemidis S. Suppressing NADPH oxidase-dependent oxidative stress in the vasculature with nitric oxide donors. Clin Exp Pharmacol Physiol 2009; 35:1395-401. [PMID: 18954334 DOI: 10.1111/j.1440-1681.2008.05055.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
1. Reactive oxygen species produced in the vasculature, including superoxide anion, contribute to the pathogenesis of cardiovascular disease states, such as atherosclerosis. A critical source of superoxide is vascular NADPH oxidase and upregulation of this enzyme brings about the oxidative stress underlying atherosclerosis. Excessive superoxide in arteries directly inactivates endothelium-derived nitric oxide (NO), compromising its vasoprotective effects. 2. Given that a reduction in NO bioavailability is key in the pathophysiology of atherosclerosis, replacement of NO by exogenously administered NO donors may restore the deficit in NO during disease. Although the organic nitrate family of NO donors is often the first choice for the acute management of symptoms of atherosclerosis and angina pectoris, most of the compounds in this class are unsuitable for long-term therapy because they cause oxidative stress by activation and upregulation of vascular NADPH oxidase and induce tolerance to subsequent nitrate treatment and endogenous NO. These problems of nitrates have not only limited their therapeutic exploitation, but have also stifled interest in newer-generation NO donors. 3. Recent evidence indicates that, in stark contrast with the organic nitrates, the newer-age diazeniumdiolate NONOate class of NO donors suppress vascular NADPH oxidase-dependent superoxide production and are less likely to induce tolerance, making them more suitable for suppression of oxidative stress in atherosclerosis. 4. Here, it is hypothesized that NONOates provide a novel means of suppressing NADPH oxidase-dependent oxidative stress to restore vascular NO levels to prevent, and even reverse, atherosclerosis.
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Affiliation(s)
- Stavros Selemidis
- Department of Pharmacology, Monash University, Melbourne, Victoria, Australia.
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129
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Garrido AM, Griendling KK. NADPH oxidases and angiotensin II receptor signaling. Mol Cell Endocrinol 2009; 302:148-58. [PMID: 19059306 PMCID: PMC2835147 DOI: 10.1016/j.mce.2008.11.003] [Citation(s) in RCA: 287] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 10/17/2008] [Accepted: 11/03/2008] [Indexed: 02/07/2023]
Abstract
Over the last decade many studies have demonstrated the importance of reactive oxygen species (ROS) production by NADPH oxidases in angiotensin II (Ang II) signaling, as well as a role for ROS in the development of different diseases in which Ang II is a central component. In this review, we summarize the mechanism of activation of NADPH oxidases by Ang II and describe the molecular targets of ROS in Ang II signaling in the vasculature, kidney and brain. We also discuss the effects of genetic manipulation of NADPH oxidase function on the physiology and pathophysiology of the renin-angiotensin system.
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130
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McCarty MF, Barroso-Aranda J, Contreras F. AMP-activated kinase may suppress NADPH oxidase activation in vascular tissues. Med Hypotheses 2009; 72:468-70. [PMID: 19181455 DOI: 10.1016/j.mehy.2008.12.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Accepted: 12/15/2008] [Indexed: 12/25/2022]
Abstract
Activation of AMP-activated kinase (AMPK) suppresses NF-kappaB-mediated transcription in endothelial cells exposed to palmitate or TNF-alpha; it also impedes angiotensin II-driven proliferation in vascular smooth muscle cells. These phenomena become predictable if we postulate that AMPK can inhibit activation of NADPH oxidase. Such an effect would make sense from a homeostatic perspective, and moreover there is direct evidence that AMPK suppresses NADPH oxidase activation in neutrophils. New evidence that sub-pathological levels of peroxynitrite can activate AMPK suggest that this enzyme may act as an "early warning signal" for oxidant stress; inhibiting NADPH oxidase would constitute a rational feedback response to such a signal.
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131
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Violi F, Basili S, Nigro C, Pignatelli P. Role of NADPH oxidase in atherosclerosis. Future Cardiol 2009; 5:83-92. [DOI: 10.2217/14796678.5.1.83] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Reactive oxidant species (ROS) seem to play a key role in the atherosclerotic process via a series of molecular changes that lead to macrophage infiltration in the endothelium and eventually to plaque formation. ROS are also implicated in arterial dysfunction via inactivation of nitric oxide, a potent vasodilator and antiaggregating molecule produced by the endothelium. Owing to the relevance of endothelial dysfunction and vascular inflammation in the process of human atherosclerosis, a lot of effort has been directed towards discovering the ROS-generating pathways implicated in the ROS upregulation. Amongst the enzymatic pathways, NADPH oxidase is the most important enzyme responsible for ROS formation in human vessels. Experimental and clinical studies suggested a role for this enzyme in initiation and progression of atherosclerotic disease. The purpose of this review is to analyze whether the basic and clinical studies are consistent with this hypothesis and to point out if determination of NADPH oxidase is useful in the setting of the atherosclerosis to predict its progression and clinical complications.
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Affiliation(s)
- Francesco Violi
- Division of Internal Medicine, Department of Experimental Medicine, University of Rome ‘La Sapienza’, Viale del Policlinico 155, 00161, Rome, Italy
| | - Stefania Basili
- Division of Internal Medicine, Department of Experimental Medicine, University of Rome ‘La Sapienza’, Viale del Policlinico 155, 00161, Rome, Italy
| | - Carmen Nigro
- Division of Internal Medicine, Department of Experimental Medicine, University of Rome ‘La Sapienza’, Viale del Policlinico 155, 00161, Rome, Italy
| | - Pasquale Pignatelli
- Division of Internal Medicine, Department of Experimental Medicine, University of Rome ‘La Sapienza’, Viale del Policlinico 155, 00161, Rome, Italy
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132
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Cui W, Matsuno K, Iwata K, Ibi M, Katsuyama M, Kakehi T, Sasaki M, Ikami K, Zhu K, Yabe-Nishimura C. NADPH Oxidase Isoforms and Anti-hypertensive Effects of Atorvastatin Demonstrated in Two Animal Models. J Pharmacol Sci 2009; 111:260-8. [DOI: 10.1254/jphs.09148fp] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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133
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134
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Selemidis S, Sobey CG, Wingler K, Schmidt HH, Drummond GR. NADPH oxidases in the vasculature: Molecular features, roles in disease and pharmacological inhibition. Pharmacol Ther 2008; 120:254-91. [DOI: 10.1016/j.pharmthera.2008.08.005] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/06/2008] [Indexed: 02/07/2023]
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135
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Carlström M, Lai EY, Ma Z, Patzak A, Brown RD, Persson AEG. Role of NOX2 in the regulation of afferent arteriole responsiveness. Am J Physiol Regul Integr Comp Physiol 2008; 296:R72-9. [PMID: 18987286 DOI: 10.1152/ajpregu.90718.2008] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NADPH oxidases (NOX) are the major source of reactive oxygen species (ROS) in the vasculature and contribute to the control of renal perfusion. The role of NOX2 in the regulation of blood pressure and afferent arteriole responsiveness was investigated in NOX2(-/-) and wild-type mice. Arteriole constrictions to ANG II (10(-14)-10(-6) mol/l) were weaker in NOX2(-/-) compared with wild types. N(omega)-nitro-l-arginine methyl ester (l-NAME; 10(-4) mol/l) treatment reduced basal diameters significantly more in NOX2(-/-) (-18%) than in wild types (-6%) and augmented ANG II responses. Adenosine (10(-11)-10(-4) mol/l) constricted arterioles of wild types but not of NOX2(-/-). However, simultaneous inhibition of adenosine type-2 receptors induced vasoconstriction, which was stronger in NOX2(-/-). Adenosine (10(-8) mol/l) enhanced the ANG II response in wild type, but not in NOX2(-/-). This sensitizing effect by adenosine was abolished by apocynin. Chronic ANG II pretreatment (14 days) did not change the ANG II responses in NOX2(-/-), but strengthened the response in wild types. ANG II pretreatment augmented the l-NAME response in NOX2(-/-) (-33%), but not in wild types. Simultaneous application of l-NAME and ANG II caused a stronger constriction in the NOX2(-/-) (-64%) than in wild types (-46%). Basal blood pressures were similar in both genotypes, however, chronic ANG II infusion elevated blood pressure to a greater extent in wild-type (15 +/- 1%) than in NOX2(-/-) (8 +/- 1%) mice. In conclusion, NOX2 plays an important role in the control of afferent arteriole tone and is involved in the contractile responses to ANG II and/or adenosine. NOX2 can be activated by elevated ANG II and may play an important role in ANG II-induced hypertension. NOX2-derived ROS scavenges nitric oxide, causing subsequent nitric oxide-deficiency.
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Affiliation(s)
- Mattias Carlström
- Dept. of Medical Cell Biology, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden.
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136
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Mieyal JJ, Gallogly MM, Qanungo S, Sabens EA, Shelton MD. Molecular mechanisms and clinical implications of reversible protein S-glutathionylation. Antioxid Redox Signal 2008; 10:1941-88. [PMID: 18774901 PMCID: PMC2774718 DOI: 10.1089/ars.2008.2089] [Citation(s) in RCA: 428] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sulfhydryl chemistry plays a vital role in normal biology and in defense of cells against oxidants, free radicals, and electrophiles. Modification of critical cysteine residues is an important mechanism of signal transduction, and perturbation of thiol-disulfide homeostasis is an important consequence of many diseases. A prevalent form of cysteine modification is reversible formation of protein mixed disulfides (protein-SSG) with glutathione (GSH). The abundance of GSH in cells and the ready conversion of sulfenic acids and S-nitroso derivatives to S-glutathione mixed disulfides suggests that reversible S-glutathionylation may be a common feature of redox signal transduction and regulation of the activities of redox sensitive thiol-proteins. The glutaredoxin enzyme has served as a focal point and important tool for evolution of this regulatory mechanism, because it is a specific and efficient catalyst of protein-SSG deglutathionylation. However, mechanisms of control of intracellular Grx activity in response to various stimuli are not well understood, and delineation of specific mechanisms and enzyme(s) involved in formation of protein-SSG intermediates requires further attention. A large number of proteins have been identified as potentially regulated by reversible S-glutathionylation, but only a few studies have documented glutathionylation-dependent changes in activity of specific proteins in a physiological context. Oxidative stress is a hallmark of many diseases which may interrupt or divert normal redox signaling and perturb protein-thiol homeostasis. Examples involving changes in S-glutathionylation of specific proteins are discussed in the context of diabetes, cardiovascular and lung diseases, cancer, and neurodegenerative diseases.
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Affiliation(s)
- John J Mieyal
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106-4965, USA.
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137
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Thomas SR, Witting PK, Drummond GR. Redox control of endothelial function and dysfunction: molecular mechanisms and therapeutic opportunities. Antioxid Redox Signal 2008; 10:1713-65. [PMID: 18707220 DOI: 10.1089/ars.2008.2027] [Citation(s) in RCA: 282] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The endothelium is essential for the maintenance of vascular homeostasis. Central to this role is the production of endothelium-derived nitric oxide (EDNO), synthesized by the endothelial isoform of nitric oxide synthase (eNOS). Endothelial dysfunction, manifested as impaired EDNO bioactivity, is an important early event in the development of various vascular diseases, including hypertension, diabetes, and atherosclerosis. The degree of impairment of EDNO bioactivity is a determinant of future vascular complications. Accordingly, growing interest exists in defining the pathologic mechanisms involved. Considerable evidence supports a causal role for the enhanced production of reactive oxygen species (ROS) by vascular cells. ROS directly inactivate EDNO, act as cell-signaling molecules, and promote protein dysfunction, events that contribute to the initiation and progression of endothelial dysfunction. Increasing data indicate that strategies designed to limit vascular ROS production can restore endothelial function in humans with vascular complications. The purpose of this review is to outline the various ways in which ROS can influence endothelial function and dysfunction, describe the redox mechanisms involved, and discuss approaches for preventing endothelial dysfunction that may highlight future therapeutic opportunities in the treatment of cardiovascular disease.
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Affiliation(s)
- Shane R Thomas
- Centre for Vascular Research, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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138
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Bai Y, Sigala W, Adams GR, Vaziri ND. Effect of exercise on cardiac tissue oxidative and inflammatory mediators in chronic kidney disease. Am J Nephrol 2008; 29:213-21. [PMID: 18797164 DOI: 10.1159/000156715] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 07/18/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND Chronic renal failure (CRF) results in diminished physical activity and increased risk of cardiovascular disease (CVD). CVD risk factors are raised by sedentary life style and ameliorated by physical fitness in the general population. Accordingly, exercise improves hypertension, endothelial dysfunction, insulin resistance, dyslipidemia, inflammation and oxidative stress in high-risk populations. This study was designed to explore the effect of exercise on oxidative and inflammatory mediators in the left ventricle (LV) of CRF rats. METHODS AND RESULTS One week after 5/6 nephrectomy female rats were housed in either regular cages or cages equipped with running wheels for 4 weeks. Sham-operated rats housed in regular cages served as controls. Sedentary CRF rats exhibited azotemia, hypertension, anemia, oxidative stress, activation of NF-kappaB and upregulations of reactive oxygen species-generating enzyme, NAD(P)H oxidase, MCP-1, cyclooxygenase-2 (COX-2), and PAI-1 in LV. The CRF rats assigned to the exercise group ran 6.8 +/- 0.7 km/day and 72 +/- 8 min/day. Voluntary exercise reversed NF-kappaB activation and lowered NAD(P)H oxidase, PAI-1, MCP-1 and COX-2 abundance, increased LV mass by raising myofibrillar proteins and ameliorated anemia without affecting renal function or arterial pressure. CONCLUSIONS CRF resulted in upregulation of prooxidant/proinflammatory pathways in LV. These changes were ameliorated by exercise, which indicates the potential cardiovascular benefit of exercise in renal insufficiency.
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Affiliation(s)
- Y Bai
- Division of Nephrology and Hypertension, University of California Irvine, Irvine, CA 92868, USA
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139
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Puddu P, Puddu GM, Cravero E, Rosati M, Muscari A. The molecular sources of reactive oxygen species in hypertension. Blood Press 2008; 17:70-7. [PMID: 18568695 DOI: 10.1080/08037050802029954] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In both animal models and humans, increased blood pressure has been associated with oxidative stress in the vasculature, i.e. an excessive endothelial production of reactive oxygen species (ROS), which may be both a cause and an effect of hypertension. In addition to NADPH oxidase, the best characterized source of ROS, several other enzymes may contribute to ROS generation, including nitric oxide synthase, lipoxygenases, cyclo-oxygenases, xanthine oxidase and cytochrome P450 enzymes. It has been suggested that also mitochondria could be considered a major source of ROS: in situations of metabolic perturbation, increased mitochondrial ROS generation might trigger endothelial dysfunction, possibly contributing to the development of hypertension. However, the use of antioxidants in the clinical setting induced only limited effects on human hypertension or cardiovascular endpoints. More clinical studies are needed to fully elucidate this so called "oxidative paradox" of hypertension.
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Affiliation(s)
- Paolo Puddu
- Department of Internal Medicine, Aging and Nephrological Diseases, University of Bologna and S Orsola-Malpighi Hospital, Bologna, Italy
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Papparella I, Ceolotto G, Montemurro D, Antonello M, Garbisa S, Rossi G, Semplicini A. Green tea attenuates angiotensin II-induced cardiac hypertrophy in rats by modulating reactive oxygen species production and the Src/epidermal growth factor receptor/Akt signaling pathway. J Nutr 2008; 138:1596-601. [PMID: 18716156 DOI: 10.1093/jn/138.9.1596] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We previously documented a clear-cut antihypertensive effect of green teat extract (GTE), which was associated with correction of endothelial dysfunction and prevention of left ventricular hypertrophy in an angiotensin II (Ang II)-dependent model of hypertension, but the molecular mechanisms remain to be defined. As several effects of Ang II involve production of reactive oxygen species (ROS) and activation of 2nd messengers, such as mitogen-activated protein kinase (MAPK) and Akt, we investigated the effect of GTE on these signal transduction pathways in Ang II-treated rats. Rats were treated for 2 wk with Ang II infusion (700 mug.kg(-1).d(-1); n = 6, via osmotic minipumps), Ang II plus GTE (6 g/L) dissolved in the drinking water; n = 6), or vehicle (n = 6) to serve as controls. Blood pressure was monitored by telemetry throughout the study. The activation and expression of NAD(P)H oxidase subunits, protein kinase C isoforms, Src, epidermal growth factor receptor (EGFR), Akt, and MAPK were determined in the heart in vitro through immunoprecipitation and western blot analysis with specific antibodies. NAD(P)H oxidase enzymatic activity was measured by cytochrome c reduction assay. GTE blunted Ang II-induced blood pressure increase and cardiac hypertrophy. In Ang II-treated rats, GTE decreased the expression of the NAD(P)H oxidase subunit gp91(phox) and the translocation of Rac-1, as well as NAD(P)H oxidase enzymatic activity. Furthermore, it specifically reduced Ang II-induced Src, EGFR, and Akt phosphorylation. These results show that GTE blunts Ang II-induced cardiac hypertrophy specifically by regulating ROS production and the Src/EGFR/Akt signaling pathway activated by Ang II.
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Affiliation(s)
- Italia Papparella
- Department of Clinical and Experimental Medicine and Experimental Biomedical Sciences, University of Padova, 35128 Padova, Italy
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141
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142
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Petersson M, Rundqvist B, Bennett BM, Adams MA, Friberg P. Impaired nitroglycerin biotransformation in patients with chronic heart failure. Clin Physiol Funct Imaging 2008; 28:229-34. [PMID: 18384624 DOI: 10.1111/j.1475-097x.2008.00793.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Patients with chronic heart failure (CHF) often require higher doses of nitroglycerin (glyceryl trinitrate, GTN) than patients with normal cardiac function to achieve a given haemodynamic goal. Two pathways leading to biotransformation of GTN have been characterized; a high-affinity pathway operative in nanomolar concentration ranges yielding predominantly 1,2-glyceryl dinitrate (1,2-GDN), and a low-affinity pathway operative at higher, micromolar concentrations of GTN associated with a greater proportion of 1,3-GDN formation. We tested the hypothesis that, at a given GTN-induced blood pressure reduction, the CHF group would present with: (i) higher concentrations of GTN; and (ii) decreased ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN compared with healthy subjects (HS). METHODS Twelve patients with CHF (left ventricular ejection fraction 20 +/- 5%, NYHA III) and nine HS were investigated during a right cardiac catheterization. GTN was titrated intravenously until mean arterial blood pressure (MAP) was reduced by 15%. RESULTS At arterial GTN concentrations of 27.2 [10.0-57.8] nmol l(-1) in CHF and 2.8 [2.5-3.5] nmol l(-1) in HS [median (quartile range), P<0.05 between groups], MAP and mean capillary wedge pressures were reduced similarly in both groups (approx. 15% and 65%, respectively, P = NS between groups). The ratios of 1,2-GDN/GTN and 1,2-GDN/1,3-GDN were lower in CHF (0.86 [0.28-1.58] and 5.8 [5.6-6.3]) compared with HS [1.91 (1.54-2.23) and 7.6 (7.2-10.2), P<0.05], with a negative correlation between the 1,2-GDN/1,3-GDN ratio and the arterial GTN concentrations in the CHF patients (R = -0.8, P<0.05). CONCLUSION Patients with CHF have attenuated GTN responsiveness and decreased relative formation of 1,2-GDN in comparison with HS, indicating an altered biotransformation of GTN.
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Affiliation(s)
- Magnus Petersson
- Department of Cardiology, Sahlgrenska University Hospital, Göteborg, Sweden
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Abstract
Accumulating evidence supports the importance of redox signaling in the pathogenesis and progression of hypertension. Redox signaling is implicated in many different physiological and pathological processes in the vasculature. High blood pressure is in part determined by elevated total peripheral vascular resistance, which is ascribed to dysregulation of vasomotor function and structural remodeling of blood vessels. Aberrant redox signaling, usually induced by excessive production of reactive oxygen species (ROS) and/or by decreases in antioxidant activity, can induce alteration of vascular function. ROS increase vascular tone by influencing the regulatory role of endothelium and by direct effects on the contractility of vascular smooth muscle. ROS contribute to vascular remodeling by influencing phenotype modulation of vascular smooth muscle cells, aberrant growth and death of vascular cells, cell migration, and extracellular matrix (ECM) reorganization. Thus, there are diverse roles of the vascular redox system in hypertension, suggesting that the complexity of redox signaling in distinct spatial spectrums should be considered for a better understanding of hypertension.
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Affiliation(s)
- Moo Yeol Lee
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia 30322, USA
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144
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Lambeth JD, Krause KH, Clark RA. NOX enzymes as novel targets for drug development. Semin Immunopathol 2008; 30:339-63. [PMID: 18509646 DOI: 10.1007/s00281-008-0123-6] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Accepted: 04/25/2008] [Indexed: 02/07/2023]
Abstract
The members of the NOX/DUOX family of NADPH oxidases mediate such physiologic functions as host defense, cell signaling, and thyroid hormone biosynthesis through the generation of reactive oxygen species (ROS), including superoxide anion and hydrogen peroxide. Moreover, ROS are involved in a broad range of fundamental biochemical and cellular processes, and data accumulated in recent years indicate that the NOX enzymes comprise one of the most important biological sources of ROS. Given the high biochemical reactivity of ROS, it is not surprising that they have been implicated in a wide variety of pathologies and diseases. Prominent among the settings that feature ROS-mediated tissue injury are disorders associated with inflammation, aging, and progressive degenerative changes in cells and organ systems, and it appears that essentially no organ system is exempt. Among the disorders currently believed to be mediated at least in part by NOX-derived ROS are hypertension, aortic aneurysm, myocardial infarction (and other ischemia-reperfusion disorders), pulmonary fibrosis and hypertension, amyotropic lateral sclerosis, Alzheimer's disease, Parkinson's disease, ischemic stroke, diabetic nephropathy, and renal cell carcinoma. Several small-molecule and peptide inhibitors of the NOX enzymes have been useful in experimental studies, but issues of specificity, potency, and toxicity militate against any of the existing published compounds as candidates for drug development. Given the broad array of disease targets documented in recent work, the time is here for vigorous efforts to develop clinically useful inhibitors of the NOX enzymes. As most (though not all) NOX-related diseases appear to be mediated by a single member of the NOX family, agents with isoform specificity will be preferred, although broadly active NOX inhibitors may prove to be useful in some settings.
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145
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Rush JWE, Aultman CD. Vascular biology of angiotensin and the impact of physical activity. Appl Physiol Nutr Metab 2008; 33:162-72. [PMID: 18347668 DOI: 10.1139/h07-147] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The renin-angiotensin system (RAS) is important for regulating blood pressure and extracellular fluid. The concept of the RAS has recently evolved from a classical systemic endocrine system to an appreciation of local RASs functioning in a paracrine manner, including in the vascular wall. Angiotensin II (AII), the main effector of the RAS, is a potent vasoconstrictor formed by the action of angiotensin-converting enzyme (ACE). ACE is multifunctional and also destroys the endogenous vasodilator bradykinin. A recently discovered novel ACE2 enzyme is responsible for forming a vasodilatory compound, angiotensin 1-7, from AII. Thus, the actions of ACE and ACE2 are antagonistic. Tissue actions of AII are mediated by specific receptors, AT1 and AT2, with AT1 mediating the classical actions. AT1-stimulated vasoconstricton occurs via phospholipase-D-mediated second messenger generation directly, and indirectly via the coupling of AT1 to the prooxidant enzyme NADPH oxidase. Since the vascular NADPH oxidase is a major source of vascular reactive oxygen species generation and is responsible for the breakdown of the vasodilator nitric oxide (NO), there is another potential link between RAS and regulation of vasodilatory pathways. AT2 signaling is antagonistic to AT1 signaling, and results in bradykinin and NO formation. Chronic AII signaling induces vascular dysfunction, whereas pharmacological management of the RAS can not only control blood pressure, but also correct endothelial dysfunction in hypertensives. Exercise training can also improve endothelial function in hypertensives, raising the question of whether there is a potential role for RAS in mediating the vascular effects of exercise training. Recent studies have demonstrated reductions in the expression of NADPH oxidase components in the vascular wall in response to exercise training, thus tempering one of the main cellular effectors of AII, and this is associated with reduced vascular ROS production and enhanced NO bioavailability. Importantly, it has now been demonstrated in human arteries that exercise training also tempers vascular AT1 receptor expression and AII-induced vasoconstriction, while enhancing endothelium-dependent dilation. The signals responsible for these chronic adaptations are not clearly understood, and may include changes in RAS components prompted by acute exercise. ACE genotype may have an effect on physical activity levels and on the cardiovascular responses to exercise training, and the II genotype (compared with ID and DD) is associated with the largest endothelium-dependent dilations in athletes compared with those in sedentary individuals. Thus, the tissue location of the RAS, the complement of ACE/ACE2, the receptor expression of AT1/AT2, and the ACE genotype are all variables that could impact the vascular responses to exercise training, but the responses of most of these variables to regular exercise training and the mechanisms responsible have not been systematically studied.
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Affiliation(s)
- James W E Rush
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
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Hayashi T, Yamashita C, Matsumoto C, Kwak CJ, Fujii K, Hirata T, Miyamura M, Mori T, Ukimura A, Okada Y, Matsumura Y, Kitaura Y. Role of gp91phox-containing NADPH oxidase in left ventricular remodeling induced by intermittent hypoxic stress. Am J Physiol Heart Circ Physiol 2008; 294:H2197-203. [PMID: 18326795 DOI: 10.1152/ajpheart.91496.2007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intermittent hypoxia due to sleep apnea syndrome is associated with cardiovascular diseases. However, the precise mechanisms by which intermittent hypoxic stress accelerates cardiovascular diseases are largely unclear. The aim of this study was to investigate the role of gp91(phox)-containing NADPH oxidase in the development of left ventricular (LV) remodeling induced by intermittent hypoxic stress in mice. Male gp91(phox)-deficient (gp91(-/-)) mice (n = 26) and wild-type (n = 39) mice at 7-12 wk of age were exposed to intermittent hypoxia (30 s of 4.5-5.5% O(2) followed by 30 s of 21% O(2) for 8 h/day during daytime) or normoxia for 10 days. Mean blood pressure and LV systolic and diastolic function were not changed by intermittent hypoxia in wild-type or gp91(-/-) mice, although right ventricular systolic pressure tended to be increased. In wild-type mice, intermittent hypoxic stress significantly increased the diameter of cardiomyocytes and interstitial fibrosis in LV myocardium. Furthermore, intermittent hypoxic stress increased superoxide production, 4-hydroxy-2-nonenal protein, TNF-alpha and transforming growth factor-beta mRNA, and NF-kappaB binding activity in wild-type, but not gp91(-/-), mice. These results suggest that gp91(phox)-containing NADPH oxidase plays a crucial role in the pathophysiology of intermittent hypoxia-induced LV remodeling through an increase of oxidative stress.
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Affiliation(s)
- Tetsuya Hayashi
- Department of Internal Medicine III, Osaka Medical College, 2-7 Daigakumachi, Takatsuki, Osaka, Japan.
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Jin L, Lagoda G, Leite R, Webb RC, Burnett AL. NADPH Oxidase Activation: A Mechanism of Hypertension-Associated Erectile Dysfunction. J Sex Med 2008; 5:544-51. [DOI: 10.1111/j.1743-6109.2007.00733.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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148
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Abstract
PURPOSE OF REVIEW Angiotensin II regulates vasoconstriction, homeostasis of salt and water, and cardiovascular hypertrophy and remodeling. Angiotensin II is a potent activator of NAD(P)H oxidase in the cardiovascular system, and augments production of reactive oxygen species. Numerous signaling pathways in response to angiotensin II are mediated by reactive oxygen species and oxidative stress is deeply associated with the progression of cardiovascular disease. The purpose of this review is to discuss the mechanism of reactive oxygen species formation and the pathophysiological effects of angiotensin II in the cardiovascular system. RECENT FINDINGS Recent studies have demonstrated novel molecular mechanisms of reactive oxygen species generation by angiotensin II and signaling pathways including cell proliferation, hypertrophy and apoptosis. In spite of these findings that strongly suggest the benefits of angiotensin II inhibition for cardiovascular disease, the clinical effects of angiotensin II-induced reactive oxygen species on the cardiovascular system are still controversial. SUMMARY We focus on the effects of angiotensin II-induced oxidative stress on cardiovascular function and remodeling after discussing the source of reactive oxygen species and novel signaling pathways in response to reactive oxygen species.
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Affiliation(s)
- Hirofumi Hitomi
- Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan.
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149
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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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150
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Abstract
NADPH oxidases have recently been shown to contribute to the pathogenesis of hypertension. The development of specific inhibitors of these enzymes has focused attention on their potential therapeutic use in hypertensive disease. Two of the most specific inhibitors, gp91ds-tat and apocynin, have been shown to decrease blood pressure in animal models of hypertension. Other inhibitors, including diphenylene iodonium, aminoethyl benzenesulfono fluoride, S17834, PR39, protein kinase C inhibitors, and VAS2870, have shown promise in vitro, but their in vivo specificity, pharmacokinetics, and effectiveness in hypertension remains to be determined. Of importance, the currently available antihypertensive agents angiotensin-converting enzyme inhibitors and angiotensin receptor blockers also effectively inhibit NADPH oxidase activation. Similarly, the cholesterol-lowering agents, statins, have been shown to attenuate NADPH oxidase activation. Although, antioxidants act to scavenge the reactive oxygen species produced by these enzymes, their effectiveness is limited. Targeting NADPH homologues may have a distinct advantage over current therapies because it would specifically prevent the pathophysiological formation of reactive oxygen species that contributes to hypertension.
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Affiliation(s)
- Holly C Williams
- Division of Cardiology, Emory University, Atlanta, GA 30322, USA
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