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Muminovic A, Chirkov YY, Horowitz JD. Effects of Soluble Guanylate Cyclase Stimulators and Activators on Anti-Aggregatory Signalling in Patients with Coronary Artery Spasm. Int J Mol Sci 2023; 24:ijms24119273. [PMID: 37298225 DOI: 10.3390/ijms24119273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/16/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
Impairment of the nitric oxide/soluble guanylate cyclase (NO)/sGC) signalling cascade is associated with many forms of cardiovascular disease, resulting not only in compromised vasodilatation but also loss of anti-aggregatory homeostasis. Myocardial ischaemia, heart failure, and atrial fibrillation are associated with moderate impairment of NO/sGC signalling, and we have recently demonstrated that coronary artery spasm (CAS) is engendered by severe impairment of platelet NO/sGC activity resulting in combined platelet and vascular endothelial damage. We therefore sought to determine whether sGC stimulators or activators might normalise NO/sGC homeostasis in platelets. ADP-induced platelet aggregation and its inhibition by the NO donor sodium nitroprusside (SNP), the sGC stimulator riociguat (RIO), and the sCG activator cinaciguat (CINA) alone or in addition to SNP were quantitated. Three groups of individuals were compared: normal subjects (n = 9), patients (Group 1) with myocardial ischaemia, heart failure and/or atrial fibrillation (n = 30), and patients (Group 2) in the chronic stage of CAS (n = 16). As expected, responses to SNP were impaired (p = 0.02) in patients versus normal subjects, with Group 2 patients most severely affected (p = 0.005). RIO alone exerted no anti-aggregatory effects but potentiated responses to SNP to a similar extent irrespective of baseline SNP response. CINA exerted only intrinsic anti-aggregatory effects, but the extent of these varied directly (r = 0.54; p = 0.0009) with individual responses to SNP. Thus, both RIO and CINA tend to normalise anti-aggregatory function in patients in whom NO/sGC signalling is impaired. The anti-aggregatory effects of RIO consist entirely of potentiation of NO, which is not selective of platelet NO resistance. However, the intrinsic anti-aggregatory effects of CINA are most marked in individuals with initially normal NO/sGC signalling, and thus their magnitude is at variance with extent of physiological impairment. These data suggest that RIO and other sGC stimulators should be evaluated for clinical utility in both prophylaxis and treatment of CAS.
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Affiliation(s)
- Armin Muminovic
- Basil Hetzel Institute for Translational Research, University of Adelaide, 37a Woodville Road, Adelaide, SA 5011, Australia
| | - Yuliy Y Chirkov
- Basil Hetzel Institute for Translational Research, University of Adelaide, 37a Woodville Road, Adelaide, SA 5011, Australia
| | - John D Horowitz
- Basil Hetzel Institute for Translational Research, University of Adelaide, 37a Woodville Road, Adelaide, SA 5011, Australia
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Chirkov YY, Nguyen TH, Horowitz JD. Impairment of Anti-Aggregatory Responses to Nitric Oxide and Prostacyclin: Mechanisms and Clinical Implications in Cardiovascular Disease. Int J Mol Sci 2022; 23:ijms23031042. [PMID: 35162966 PMCID: PMC8835624 DOI: 10.3390/ijms23031042] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/10/2022] [Accepted: 01/15/2022] [Indexed: 01/27/2023] Open
Abstract
The propensity towards platelet-rich thrombus formation increases substantially during normal ageing, and this trend is mediated by decreases in platelet responsiveness to the anti-aggregatory nitric oxide (NO) and prostacyclin (PGI2) pathways. The impairment of soluble guanylate cyclase and adenylate cyclase-based signalling that is associated with oxidative stress represents the major mechanism of this loss of anti-aggregatory reactivity. Platelet desensitization to these autacoids represents an adverse prognostic marker in patients with ischemic heart disease and may contribute to increased thrombo-embolic risk in patients with heart failure. Patients with platelet resistance to PGI2 also are unresponsive to ADP receptor antagonist therapy. Apart from ischemia, diabetes and aortic valve disease are also associated with impaired anti-aggregatory homeostasis. This review examines the association of impaired platelet cyclic nucleotide (i.e., cGMP and cAMP) signalling with the emerging evidence of thromboembolic risk in cardiovascular diseases, and discusses the potential therapeutic strategies targeting this abnormality.
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Affiliation(s)
| | | | - John D. Horowitz
- Correspondence: ; Tel.: +61(08)-8222-7635; Fax: +61(08)-8222-6422
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Velagic A, Qin C, Woodman OL, Horowitz JD, Ritchie RH, Kemp-Harper BK. Nitroxyl: A Novel Strategy to Circumvent Diabetes Associated Impairments in Nitric Oxide Signaling. Front Pharmacol 2020; 11:727. [PMID: 32508651 PMCID: PMC7248192 DOI: 10.3389/fphar.2020.00727] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 05/01/2020] [Indexed: 12/19/2022] Open
Abstract
Diabetes is associated with an increased mortality risk due to cardiovascular complications. Hyperglycemia-induced oxidative stress underlies these complications, leading to an impairment in endogenous nitric oxide (NO•) generation, together with reductions in NO• bioavailability and NO• responsiveness in the vasculature, platelets and myocardium. The latter impairment of responsiveness to NO•, termed NO• resistance, compromises the ability of traditional NO•-based therapeutics to improve hemodynamic status during diabetes-associated cardiovascular emergencies, such as acute myocardial infarction. Whilst a number of agents can ameliorate (e.g. angiotensin converting enzyme [ACE] inhibitors, perhexiline, statins and insulin) or circumvent (e.g. nitrite and sGC activators) NO• resistance, nitroxyl (HNO) donors offer a novel opportunity to circumvent NO• resistance in diabetes. With a suite of vasoprotective properties and an ability to enhance cardiac inotropic and lusitropic responses, coupled with preserved efficacy in the setting of oxidative stress, HNO donors have intact therapeutic potential in the face of diminished NO• signaling. This review explores the major mechanisms by which hyperglycemia-induced oxidative stress drives NO• resistance, and the therapeutic potential of HNO donors to circumvent this to treat cardiovascular complications in type 2 diabetes mellitus.
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Affiliation(s)
- Anida Velagic
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Chengxue Qin
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Owen L Woodman
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - John D Horowitz
- Basil Hetzel Institute, Queen Elizabeth Hospital, University of Adelaide, Adelaide, SA, Australia
| | - Rebecca H Ritchie
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.,Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Barbara K Kemp-Harper
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
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Procter NEK, Hurst NL, Nooney VB, Imam H, De Caterina R, Chirkov YY, Horowitz JD. New Developments in Platelet Cyclic Nucleotide Signalling: Therapeutic Implications. Cardiovasc Drugs Ther 2017; 30:505-513. [PMID: 27358171 DOI: 10.1007/s10557-016-6671-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Altered platelet physiology may contribute to the emergence of thrombosis in patients with many forms of cardiovascular disease. Excess platelet activation may reflect increased stimulation of pro-aggregatory pathways. There is, however, increasing evidence that excessive platelet response, due to impaired efficacy of anti-aggregatory autacoids such as nitric oxide (NO) and prostacyclin (PGI2), may be just as important. For example, diminished platelet response to NO has been documented in acute and chronic myocardial ischaemia, heart failure, aortic valve disease and in the presence of hyperglycaemia. This "NO resistance" has been shown to reflect both the scavenging of NO by reactive oxygen species and dysfunction of its intracellular "receptor", soluble guanylate cyclase. Importantly, these abnormalities of NO signalling are potentially reversible through judicious application of pharmacotherapy. The analogous condition of impaired PGI2/adenylate cyclase (AC) signalling has received comparatively less attention to date. We have shown that platelet response to prostaglandin E1 (PGE1) is frequently impaired in patients with symptomatic myocardial ischaemia. Because the effects of ADP receptor antagonists such as clopidogrel and ticagrelor at the level of the P2Y12 receptor are coupled with changes in activity of AC, impaired response to PGE1 might imply both increased thrombotic risk and a reduced efficacy of anti-aggregatory drugs. Accordingly, patient response to treatment with clopidogrel is determined not only by variability of clopidogrel bio-activation, but also extensively by the integrity of platelet AC signalling. We here review these recent developments and their emerging therapeutic implications for thrombotic disorders.
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Affiliation(s)
- Nathan E K Procter
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of Adelaide, Cardiology Unit, 28 Woodville Rd, Woodville South, Adelaide, SA, 5011, Australia
| | - Nicola L Hurst
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of Adelaide, Cardiology Unit, 28 Woodville Rd, Woodville South, Adelaide, SA, 5011, Australia
| | - Vivek B Nooney
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of South Australia, Adelaide, Australia
| | - Hasan Imam
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of Adelaide, Cardiology Unit, 28 Woodville Rd, Woodville South, Adelaide, SA, 5011, Australia
| | - Raffaele De Caterina
- Institute of Cardiology and Centre for Excellence on Aging, "G. d'Annunzio" University, Chieti, Italy
| | - Yuliy Y Chirkov
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of Adelaide, Cardiology Unit, 28 Woodville Rd, Woodville South, Adelaide, SA, 5011, Australia
| | - John D Horowitz
- Basil Hetzel Institute for Translational Research, The Queen Elizabeth Hospital, The University of Adelaide, Cardiology Unit, 28 Woodville Rd, Woodville South, Adelaide, SA, 5011, Australia.
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Dyszkiewicz-Korpanty AM, Frenkel EP, Sarode R. Approach to the Assessment of Platelet Function: Comparison between Optical-based Platelet-rich Plasma and Impedance-based Whole Blood Platelet Aggregation Methods. Clin Appl Thromb Hemost 2016; 11:25-35. [PMID: 15678270 DOI: 10.1177/107602960501100103] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Platelet aggregation studies play an important role in the assessment of hereditary and acquired platelet function defects. The first aggregation test introduced into laboratory practice used platelet-rich plasma (PRP) where aggregation was detected by an optical method. The assessment of platelet function using whole blood (WB) aggregation by an impedance method followed up nearly 20 years later. The WB impedance aggregation assay appears to be superior to the optical method because it 1) evaluates platelets in a physiologic milieu in the presence of red and white blood cells, which are known to modulate platelet function; 2) is faster; 3) has higher sensitivity; and 4) does not require centrifugation, thus avoiding injury to platelets and loss of giant thrombocytes. These two assays were compared. Clearly, the WB impedance aggregation methodology has many advantages over the optical PRP assay for the assessment of the hyperactive platelet syndrome and the effects of anti-platelet drugs.
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Affiliation(s)
- Anna M Dyszkiewicz-Korpanty
- Department of Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-8852, USA
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Gender and tachycardia: independent modulation of platelet reactivity in patients with atrial fibrillation. JOURNAL OF GERIATRIC CARDIOLOGY : JGC 2016; 13:202-8. [PMID: 27103914 PMCID: PMC4826889 DOI: 10.11909/j.issn.1671-5411.2016.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Background Female patients with atrial fibrillation (AF) experience increased risk of thromboembolism compared to males, an observation that is reflected by its inclusion in the CHA2DS2VASc score. New onset AF (often associated with tachycardia) also confers upon patients increased thromboembolic risk. The mechanisms underlying this risk are uncertain, but new onset AF is associated with profound impairment of platelet nitric oxide (NO) signalling. Given that cardiovascular responses to catecholamines are gender-dependent, and that the presence of tachycardia in new onset AF may represent a response to catecholaminergic stimulation, we explored the potential impact of gender and tachycardia on platelet aggregation and NO signalling. Methods Interactions were sought in 87 AF patients between the extent of adenosine diphosphate (ADP)-induced platelet aggregation, the anti-aggregatory effects of the NO donor, sodium nitroprusside, gender, and admission heart rate. The potential impact of platelet expression of thioredoxin-interacting protein (Txnip) was also evaluated. Results Analysis of covariance confirmed the presence of physiological antagonism between platelet ADP and NO responses [F (1, 74) = 12.212, P < 0.01], while female sex correlated with impaired NO responses independent of platelet aggregability [F (2, 74) = 8.313, P < 0.01]. Admission heart rate correlated directly with platelet aggregation (r = 0.235, P < 0.05), and inversely with NO response (r = −0.331, P < 0.01). Txnip expression varied neither with gender nor with heart rate. Conclusions These results indicate that gender and heart rate are independent determinants of platelet function. Prospective studies of the putative benefit of reversal of tachycardia on restoration of normal platelet function are therefore a priority.
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Procter NEK, Ball J, Liu S, Hurst N, Nooney VB, Goh V, Stafford I, Heresztyn T, Carrington M, Ngo DTM, Hylek EM, Isenberg JS, Chirkov YY, Stewart S, Horowitz JD. Impaired platelet nitric oxide response in patients with new onset atrial fibrillation. Int J Cardiol 2014; 179:160-5. [PMID: 25464437 DOI: 10.1016/j.ijcard.2014.10.137] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 09/30/2014] [Accepted: 10/21/2014] [Indexed: 01/08/2023]
Abstract
BACKGROUND Clinical factors associated with thromboembolic risk in AF patients are well characterized and include new onset AF. Biochemically, AF is associated with inflammatory activation and impairment of nitric oxide (NO) signalling, which may also predispose to thromboembolism: the bases for variability in these anomalies have not been identified. We therefore sought to identify correlates of impaired platelet NO signalling in patients hospitalized with atrial fibrillation (AF), and to evaluate the impact of acuity of AF. METHODS 87 patients hospitalized with AF were evaluated. Platelet aggregation, and its inhibition by the NO donor sodium nitroprusside, was evaluated using whole blood impedance aggregometry. Correlates of impaired NO response were examined and repeated in a "validation" cohort of acute cardiac illnesses. RESULTS Whilst clinical risk scores were not significantly correlated with integrity of NO signalling, new onset AF was associated with impaired NO response (6 ± 5% inhibition versus 25 ± 4% inhibition for chronic AF, p<0.01). New onset AF was a multivariate correlate (p<0.01) of impaired NO signalling, along with platelet ADP response (p<0.001), whereas the associated tachycardia was not. Platelet ADP response was predicted by elevation of plasma thrombospondin-1 concentrations (p<0.01). Validation cohort evaluations confirmed that acute AF was associated with significant (p<0.05) impairment of platelet NO response, and that neither acute heart failure nor acute coronary syndromes were associated with similar impairment. CONCLUSION Recent onset of AF is associated with marked impairment of platelet NO response. These findings may contribute to thromboembolic risk in such patients.
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Affiliation(s)
- Nathan E K Procter
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Jocasta Ball
- National Health and Medical Research Council (NHMRC), Centre of Excellence to Reduce Inequality in Heart Disease, Baker IDI Heart and Diabetes Institute, Australian Catholic University, Melbourne, Australia
| | - Saifei Liu
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Nicola Hurst
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Vivek B Nooney
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of South Australia, Adelaide, Australia
| | - Vincent Goh
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Irene Stafford
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Tamila Heresztyn
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Melinda Carrington
- National Health and Medical Research Council (NHMRC), Centre of Excellence to Reduce Inequality in Heart Disease, Baker IDI Heart and Diabetes Institute, Australian Catholic University, Melbourne, Australia
| | - Doan T M Ngo
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | | | - Jeffrey S Isenberg
- Vascular Medicine Institute, University of Pittsburgh Department of Medicine, Pittsburgh, PA, USA
| | - Yuliy Y Chirkov
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
| | - Simon Stewart
- National Health and Medical Research Council (NHMRC), Centre of Excellence to Reduce Inequality in Heart Disease, Baker IDI Heart and Diabetes Institute, Australian Catholic University, Melbourne, Australia
| | - John D Horowitz
- Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia.
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Dautov RF, Ngo DTM, Licari G, Liu S, Sverdlov AL, Ritchie RH, Kemp-Harper BK, Horowitz JD, Chirkov YY. The nitric oxide redox sibling nitroxyl partially circumvents impairment of platelet nitric oxide responsiveness. Nitric Oxide 2013; 35:72-8. [PMID: 24012721 DOI: 10.1016/j.niox.2013.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 08/21/2013] [Accepted: 08/28/2013] [Indexed: 01/17/2023]
Abstract
Impaired platelet responsiveness to nitric oxide (NO resistance) is a common characteristic of many cardiovascular disease states and represents an independent risk factor for cardiac events and mortality. NO resistance reflects both scavenging of NO by superoxide (O2(-)), and impairment of the NO receptor, soluble guanylate cyclase (sGC). There is thus an urgent need for circumvention of NO resistance in order to improve clinical outcomes. Nitroxyl (HNO), like NO, produces vasodilator and anti-aggregatory effects, largely via sGC activation, but is not inactivated by O2(-). We tested the hypothesis that HNO circumvents NO resistance in human platelets. In 57 subjects with or without ischemic heart disease, platelet responses to the HNO donor isopropylamine NONOate (IPA/NO) and the NO donor sodium nitroprusside (SNP) were compared. While SNP (10μM) induced 29±3% (p<0.001) inhibition of platelet aggregation, IPA/NO (10μM) caused 75±4% inhibition (p<0.001). In NO-resistant subjects (n=28), the IPA/NO:SNP response ratio was markedly increased (p<0.01), consistent with partial circumvention of NO resistance. Similarly, cGMP accumulation in platelets was greater (p<0.001) with IPA/NO than with SNP stimulation. The NO scavenger carboxy-PTIO (CPTIO, 200μM) inhibited SNP and IPA/NO responses by 92±7% and 17±4% respectively (p<0.001 for differential inhibition), suggesting that effects of IPA/NO are only partially NO-mediated. ODQ (10μM) inhibited IPA/NO responses by 36±8% (p<0.001), consistent with a contribution of sGC/haem to IPA/NO inhibition of aggregation. There was no significant relationship between whole blood ROS content and IPA/NO responses. Thus the HNO donor IPA/NO substantially circumvents platelet NO resistance while acting, at least partially, as a haem-mediated sGC activator.
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Affiliation(s)
- R F Dautov
- Cardiology Unit, Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Woodville, Australia.
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Sverdlov AL, Chan WPA, Procter NEK, Chirkov YY, Ngo DTM, Horowitz JD. Reciprocal regulation of NO signaling and TXNIP expression in humans: impact of aging and ramipril therapy. Int J Cardiol 2013; 168:4624-30. [PMID: 23958415 DOI: 10.1016/j.ijcard.2013.07.159] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 07/19/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND Impaired tissue responsiveness to nitric oxide (NO) occurs in many cardiovascular diseases as well as with advanced age and is a correlate of poor outcomes. This phenomenon results from oxidative stress, with NO "scavenging" and dysfunction of soluble guanylate cyclase (sGC). Thioredoxin-interacting protein (TXNIP) is a major intracellular regulator of inflammatory activation and redox stress, but its interactions with NO/sGC are poorly understood. We have now evaluated the relationship between platelet TXNIP expression and function of the NO/sGC axis in subjects of varying age and during therapy with ramipril. METHODS & RESULTS Young (n=42) and aging (n=49) subjects underwent evaluation of platelet TXNIP content. Aging subjects additionally had measurements of platelet NO responsiveness and routine biochemistry. Platelet TXNIP content was greater (376±33 units) in the aging compared to younger subjects (289±13 units; p<0.05). In the aging subjects there was a significant negative correlation (r=-0.50, p<0.001) between platelet TXNIP content and NO responsiveness. In a separate cohort of 15 subjects two week treatment with ramipril, which reversed platelet NO resistance and potentiated sGC activity, also decreased platelet TXNIP content by 40% (p=0.011). CONCLUSIONS Platelet TXNIP content increases with aging, varies inversely with responsiveness to NO, and diminishes rapidly following treatment with ramipril. These data suggest that TXNIP-induced oxidative stress may be a critical modulator of tissue resistance to NO, a fundamental basis for cardiovascular disease. Analogously suppression of TXNIP expression can potentially be utilized as an index of restoration of cardiovascular homeostasis.
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Affiliation(s)
- Aaron L Sverdlov
- Cardiology Unit, Basil Hetzel Institute, The Queen Elizabeth Hospital, University of Adelaide, Adelaide, Australia
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Kanaki AI, Sarafidis PA, Georgianos PI, Kanavos K, Tziolas IM, Zebekakis PE, Lasaridis AN. Effects of low-dose atorvastatin on arterial stiffness and central aortic pressure augmentation in patients with hypertension and hypercholesterolemia. Am J Hypertens 2013; 26:608-16. [PMID: 23449607 DOI: 10.1093/ajh/hps098] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Experimental and clinical data suggest that statins exert anti-inflammatory and antiproliferative actions on vasculature beyond their lipid-lowering properties. Whether these pleiotropic effects of statins translate into a beneficial effect on arterial stiffness is not clear. This study aimed to evaluate the potential effects of low-dose atorvastatin treatment on arterial stiffness and central arterial pressure waveforms in patients with mild hypertension and hypercholesterolemia. METHODS In a double-blind, randomized, placebo-controlled fashion, 50 hypertensive and hypercholesterolemic patients were allocated to receive 10 mg of atorvastatin or placebo for 26 weeks. Arterial stiffness was assessed by aortic pulse-wave velocity (PWV) using a Sphygmocor device. Central arterial pressure waveform parameters were estimated by radial artery applanation tonometry. Heart rate-adjusted augmentation index (AIx(75)) was used as measure of wave reflections. RESULTS At study end, aortic PWV (9.0 ± 1.5 vs. 10.9 ± 2.6 m/sec; P < 0.001) and AIx(75) (24.9% ± 9.7% vs 28.8% ± 11.8%; P < 0.001) were significantly lower in the atorvastatin group than that placebo group. Furthermore, decreases in central aortic systolic blood pressure and pulse pressure were evident at study-end with atorvastatin but not with placebo (130 ± 8 vs. 138 ± 6 mm Hg, P < 0.001; 48 ± 7 vs. 53 ± 6 mm Hg, P < 0.05, respectively). Atorvastatin-induced reductions in aortic PWV during follow-up showed significant associations with changes in AIx(75) and central aortic systolic blood pressure and pulse pressure. CONCLUSIONS This study shows that low-dose atorvastatin treatment improves arterial stiffness and exerts a reduction on central aortic pressures. These effects may represent a potential mechanism of cardiovascular risk reduction observed with statin use. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Database Identifier Number: NCT01126684.
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Affiliation(s)
- Aggeliki I Kanaki
- Section of Nephrology and Hypertension, 1st Department of Medicine, AHEPA University Hospital, Thessaloniki, Greece
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Rajendran S, Chirkov YY. Platelet hyperaggregability: impaired responsiveness to nitric oxide ("platelet NO resistance") as a therapeutic target. Cardiovasc Drugs Ther 2008; 22:193-203. [PMID: 18327704 DOI: 10.1007/s10557-008-6098-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2007] [Accepted: 02/07/2008] [Indexed: 11/25/2022]
Abstract
Platelet hyperaggregability and associated thrombosis have been documented in a number of cardiovascular disease states. While one of the current mainstays of anti-thrombotic treatment (i.e. aspirin, clopidogrel, glycoprotein IIb/IIIa antagonists) has been directed at reducing platelet activation and aggregation, it is apparent that there are limitations to the effectiveness of these therapies. Nitric oxide (NO) plays an important role in platelet physiology. The ability of NO to regulate cyclic guanosine-3,'5'-monophosphate (cGMP), via activation of soluble guanylate cyclase, is the principal mechanism of negative control over platelet activity. NO is not only of the endothelial source, it is also released from activated platelets, providing a negative feedback. Studies in patients with symptomatic ischemia, chronic heart failure, diabetes and various risk factors for cardiovascular disease have demonstrated that platelets from these subjects exhibit reduced responsiveness to the anti-aggregating efficacy of NO: a phenomenon termed "platelet NO resistance". It constitutes an impaired physiological response to endogenous NO (endothelium-derived relaxing factor or EDRF), and as such may contribute to the increased risk of ischemic events. NO resistance also accounts for reduced pharmaco-activity of exogenous NO donors, e.g. organic nitrates. Platelet NO resistance results largely from a combination of "scavenging" of NO by superoxide anion radical and inactivation of soluble guanylate cyclase. NO resistance has both diagnostic and prognostic implications. The current review examines the association of platelet NO resistance with pathological hyperaggregability and discusses potential therapeutic strategies targeting this abnormality.
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Affiliation(s)
- Sharmalar Rajendran
- Cardiology Unit, The Basil Hetzel Institute, The Queen Elizabeth Hospital, Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia
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Hamilton PK, Lockhart CJ, Quinn CE, McVeigh GE. Arterial stiffness: clinical relevance, measurement and treatment. Clin Sci (Lond) 2007; 113:157-70. [PMID: 17623012 DOI: 10.1042/cs20070080] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Most traditional cardiovascular risk factors alter the structure and/or function of arteries. An assessment of arterial wall integrity could therefore allow accurate prediction of cardiovascular risk in individuals. The term 'arterial stiffness' denotes alterations in the mechanical properties of arteries, and much effort has focused on how best to measure this. Pulse pressure, pulse wave velocity, pulse waveform analysis, localized assessment of blood vessel mechanics and other methods have all been used. We review the methodology underlying each of these measures, and present an evidence-based critique of their relative merits and limitations. An overview is also given of the drug therapies that may prove useful in the treatment of patients with altered arterial mechanics.
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Affiliation(s)
- Paul K Hamilton
- Department of Therapeutics and Pharmacology, Queen's University Belfast, Whitla Medical Building, Belfast, UK.
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Chirkov YY, Horowitz JD. Impaired tissue responsiveness to organic nitrates and nitric oxide: a new therapeutic frontier? Pharmacol Ther 2007; 116:287-305. [PMID: 17765975 DOI: 10.1016/j.pharmthera.2007.06.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 06/27/2007] [Indexed: 01/08/2023]
Abstract
Nitric oxide (NO) is a physiologically important modulator of both vasomotor tone and platelet aggregability. These effects of NO are predominantly mediated by cyclic guanosine-3,'5'-monophosphate (cGMP) via activation of soluble guanylate cyclase. However, in patients with ischemic heart disease, platelets and coronary/peripheral arteries are hyporesponsive to the antiaggregatory and vasodilator effects of NO donors. NO resistance is also associated with a number of coronary risk factors and presents in different disease states. It correlates with conventional measures of "endothelial dysfunction," and represents a multifaceted disorder, in which smooth muscle and platelet NO resistance are equally important, as sites of abnormal NO-driven physiology. NO resistance results largely from a combination of "scavenging" of NO by superoxide anion radical (O(2)(-)) and of (reversible) inactivation of soluble guanylate cyclase. It constitutes an impaired physiological response to endogenous NO (endothelium-derived relaxing factor, EDRF) and, as such, may contribute to the increased risk of ischemic events. Impairment in responsiveness to NO in ischemic patients implies a potential problem that those patients, in greatest need of nitrate therapy, may be least likely to respond. The prognostic impact of NO resistance at vascular and platelet levels has been demonstrated in patients with ischemic heart disease, and it has been shown that a number of agents (angiotensin-converting enzyme [ACE] inhibitors, perhexiline, insulin, and possibly statins) ameliorate this anomaly. The current review examines different aspects of the "NO resistance" phenomenon and discusses some related methodological issues.
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Affiliation(s)
- Yuliy Y Chirkov
- Cardiology Unit, The Queen Elizabeth Hospital, The University of Adelaide, S.A., Australia
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Holmes AS, Chirkov YY, Willoughby SR, Poropat S, Pereira J, Horowitz JD. Preservation of platelet responsiveness to nitroglycerine despite development of vascular nitrate tolerance. Br J Clin Pharmacol 2006; 60:355-63. [PMID: 16187967 PMCID: PMC1884829 DOI: 10.1111/j.1365-2125.2005.02437.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS Organic nitrates, via nitric oxide (NO) release, induce vasodilatation and inhibit platelet aggregation. Development of nitrate tolerance in some vascular preparations may be associated with diminished responsiveness to NO. To date it is not known to what extent vascular tolerance to organic nitrates is associated with acquired platelet hypo-responsiveness to NO. In the current study we compared the acute and chronic effects of sustained release (SR) isosorbide 5' mono-nitrate (ISMN) and transdermal nitroglycerine (TD-NTG) on blood vessels (effects on apparent arterial stiffness) and platelets (effects on responsiveness to NO donors) in patients with stable angina pectoris (SAP). METHODS Patients (n = 34) with SAP entered a blinded randomized crossover study of ISMN (120 mg) vs. intermittent TD-NTG (15 mg 24 h(-1)). Effects of each nitrate on pulse wave reflection (augmentation index (AIx)), platelet response to adenosine di-phosphate (ADP 1 micromol l(-1)), nitroglycerine (NTG 100 micromol l(-1)) and the non-nitrate NO donor sodium nitroprusside (SNP 10 micromol l(-1)), were measured pre-dose, 4 and 8 h post dose, on three occasions: 1) at the end of a pre-nitrate phase, 2) after dosing for 7 days and 3) following 14 days of full dose therapy with either nitrate. RESULTS Acutely, both ISMN and TD-NTG markedly reduced AIx. After 14 days, these effects were significantly attenuated (ANOVA, P = 0.018) but not abolished, indicating development of nitrate tolerance. Neither nitrate preparation affected ADP (1 micromol l(-1))-induced platelet aggregation. Platelet responsiveness to NTG (100 micromol l(-1)) and SNP (10 micromol l(-1)) was not diminished during chronic nitrate therapy, and there was no evidence of 'rebound' hyper-aggregability during 'nitrate-free' periods. CONCLUSIONS Chronic therapy with either ISMN or TD-NTG is associated with development of vascular tolerance. Despite the induction of vascular tolerance, platelet responsiveness to NTG and SNP remains unaffected. Therefore, development of vascular tolerance is unlikely to compromise the anti-aggregatory effects of organic nitrates, or those of endogenous NO.
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Affiliation(s)
- Andrew S Holmes
- The Cardiology Unit, The Basil Hetzel Institute, The Queen Elizabeth Hospital, Department of Medicine, The University of Adelaide, Australia
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Willoughby SR, Stewart S, Holmes AS, Chirkov YY, Horowitz JD. Platelet nitric oxide responsiveness: a novel prognostic marker in acute coronary syndromes. Arterioscler Thromb Vasc Biol 2005; 25:2661-6. [PMID: 16254202 DOI: 10.1161/01.atv.0000193622.77294.57] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Nitric oxide (NO) is critically important in the regulation of vascular tone and the inhibition of platelet aggregation. We have shown previously that patients with acute coronary syndromes (ACS) or stable angina pectoris have impaired platelet responses to NO donors when compared with normal subjects. We tested the hypotheses that platelet hyporesponsiveness to NO is a predictor of (1) cardiovascular readmission and/or death and (2) all-cause mortality in patients with ACS (unstable angina pectoris or non-Q-wave myocardial infarction). METHODS AND RESULTS Patients (n=51) with ACS had evaluation of platelet aggregation within 24 hours of coronary care unit admission using impedance aggregometry. Patients were categorized as having "normal" (> or =32% inhibition of ADP-induced aggregation with the NO donor sodium nitroprusside; 10 micromol/L; n=18) or "impaired" (<32% inhibition of ADP-induced aggregation; n=33) NO responses. We then compared the incidence of cardiovascular readmission and death during a median of 7 years of follow-up in these 2 groups. Using a Cox proportional hazards model adjusting for age, sex, index event, postdischarge medical treatment, revascularization status, left ventricular systolic dysfunction, concurrent disease states, and cardiac risk factors, impaired NO responsiveness was associated with an increased risk of the combination of cardiovascular readmission and/or death (relative risk, 2.7; 95% CI, 1.03 to 7.10; P=0.041) and all-cause mortality (relative risk, 6.3; 95% CI, 1.09 to 36.7; P=0.033). CONCLUSIONS Impaired platelet NO responsiveness is a novel, independent predictor of increased mortality and cardiovascular morbidity in patients with high-risk ACS.
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Affiliation(s)
- Scott R Willoughby
- Basil Hetzel Institute, Queen Elizabeth Hospital, Department of Medicine, University of Adelaide, Adelaide, Australia
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Attenuation of inflammation with short-term dietary intervention is associated with a reduction of arterial stiffness in subjects with hypercholesterolaemia. ACTA ACUST UNITED AC 2004. [DOI: 10.1097/00149831-200412000-00009] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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