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Soulaidopoulos S, Terentes-Printzios D, Ioakeimidis N, Tsioufis KP, Vlachopoulos C. Long-term effects of phosphodiesterase-5 inhibitors on cardiovascular outcomes and death: a systematic review and meta-analysis. EUROPEAN HEART JOURNAL. CARDIOVASCULAR PHARMACOTHERAPY 2024; 10:403-412. [PMID: 38777751 PMCID: PMC11323371 DOI: 10.1093/ehjcvp/pvae029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/29/2024] [Accepted: 05/20/2024] [Indexed: 05/25/2024]
Abstract
AIMS Phosphodiesterase 5 inhibitors (PDE5i), which are widely used for the treatment of erectile dysfunction (ED), have been found to exhibit systemic vascular benefits by improving endothelial function. In this context, we sought to evaluate the effects of PDE5i on long-term cardiovascular outcomes and mortality. METHODS AND RESULTS A comprehensive search of electronic databases was conducted up to 30 May 2023. Cohort studies comparing PDE5i treatment at any dose with other ED treatment, placebo or no treatment and minimum follow-up duration of 6 months were considered eligible. The primary endpoints were: (1) major adverse cardiovascular events (MACE) and (2) all-cause mortality. Pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated. Sixteen studies were included (1 257 759 subjects-10.5% treated with PDE5i). The majority of patients (99.4%) were men [median age 61.5 years (range 30-72.8)]. The median follow-up duration was 4.3 years (range 6 months-7.5 years). PDE5i use was associated with a significant reduction in the composite of MACE (RR 0.78, 95% CI 0.69-0.89). Moreover, the analysis of pooled data from 13 studies, demonstrated that the use of PDE5i was associated with a significantly lower risk of all-cause mortality (RR 0.70, 95% CI 0.56-0.87). CONCLUSION The use of PDE5i primarily in men with or without known coronary artery disease was associated with a lower risk for cardiovascular events and overall mortality. This information underlines that PDE5i could provide clinical benefit beyond ED treatment and could instigate the conduction of further, large-scale randomized clinical trials.
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Affiliation(s)
- Stergios Soulaidopoulos
- First Cardiology Department, Hippokration Hospital, Athens Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Dimitrios Terentes-Printzios
- First Cardiology Department, Hippokration Hospital, Athens Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Nikolaos Ioakeimidis
- First Cardiology Department, Hippokration Hospital, Athens Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Konstantinos P Tsioufis
- First Cardiology Department, Hippokration Hospital, Athens Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Charalambos Vlachopoulos
- First Cardiology Department, Hippokration Hospital, Athens Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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ElHady AK, El-Gamil DS, Abdel-Halim M, Abadi AH. Advancements in Phosphodiesterase 5 Inhibitors: Unveiling Present and Future Perspectives. Pharmaceuticals (Basel) 2023; 16:1266. [PMID: 37765073 PMCID: PMC10536424 DOI: 10.3390/ph16091266] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/25/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Phosphodiesterase 5 (PDE5) inhibitors presented themselves as important players in the nitric oxide/cGMP pathway, thus exerting a profound impact on various physiological and pathological processes. Beyond their well-known efficacy in treating male erectile dysfunction (ED) and pulmonary arterial hypertension (PAH), a plethora of studies have unveiled their significance in the treatment of a myriad of other diseases, including cognitive functions, heart failure, multiple drug resistance in cancer therapy, immune diseases, systemic sclerosis and others. This comprehensive review aims to provide an updated assessment of the crucial role played by PDE5 inhibitors (PDE5-Is) as disease-modifying agents taking their limiting side effects into consideration. From a medicinal chemistry and drug discovery perspective, the published PDE5-Is over the last 10 years and their binding characteristics are systemically discussed, and advancement in properties is exposed. A persistent challenge encountered with these agents lies in their limited isozyme selectivity; considering this obstacle, this review also highlights the breakthrough development of the recently reported PDE5 allosteric inhibitors, which exhibit an unparalleled level of selectivity that was rarely achievable by competitive inhibitors. The implications and potential impact of these novel allosteric inhibitors are meticulously explored. Additionally, the concept of multi-targeted ligands is critically evaluated in relation to PDE5-Is by inspecting the broader spectrum of their molecular interactions and effects. The objective of this review is to provide insight into the design of potent, selective PDE5-Is and an overview of their biological function, limitations, challenges, therapeutic potentials, undergoing clinical trials, future prospects and emerging uses, thus guiding upcoming endeavors in both academia and industry within this domain.
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Affiliation(s)
- Ahmed K. ElHady
- School of Life and Medical Sciences, University of Hertfordshire Hosted by Global Academic Foundation, New Administrative Capital, Cairo 11865, Egypt;
| | - Dalia S. El-Gamil
- Department of Chemistry, Faculty of Pharmacy, Ahram Canadian University, Cairo 12451, Egypt;
| | - Mohammad Abdel-Halim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo 11835, Egypt;
| | - Ashraf H. Abadi
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo 11835, Egypt;
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3
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Swiecicka A. The efficacy of PDE5 inhibitors in diabetic patients. Andrology 2023; 11:245-256. [PMID: 36367281 PMCID: PMC10107754 DOI: 10.1111/andr.13328] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/27/2022] [Accepted: 10/14/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Phosphodiesterase 5 inhibitors (PDE5i), since their introduction in the late 1990s, have proven their efficacy in treating several conditions, predominantly pulmonary hypertension and erectile dysfunction where they remain the first-line therapeutic option. However, in the recent years, growing evidence from both animal and human studies has emerged to suggest the additional benefits of PDE5i in cardiovascular and metabolic disorders. This is of specific interest to the diabetes population where prevalent cardiovascular disease and metabolic dysregulation significantly contribute to the increased morbidity and mortality. OBJECTIVES To examine the available data on the non-standard, pleiotropic effects of PDE5i in patients with diabetes mellitus. MATERIALS AND METHODS The review of the published background research, preclinical studies and clinical trials. RESULTS In human studies, PDE5 inhibition appeared to be associated with reduced cardiovascular mortality and overall improved clinical outcomes in those with established cardiovascular disease. PDE5i were also consistently found to reduce albuminuria in subjects with diabetic nephropathy. Furthermore, animal data suggest a plausible effect of this group of medication on sensory function and neuropathic symptoms in diabetic neuropathy as well as improved wound healing. A decrease in insulin resistance and augmentation of beta cell function seen in preclinical studies has not been consistently demonstrated in human trials. DISCUSSION AND CONCLUSION In animal models, PDE5 inhibition appears to decrease oxidative stress and reduce some of the micro- and macrovascular complications associated with diabetes. However, data from human trials are limited and largely inconsistent, highlighting the need for adequately powered, randomised-controlled trials in diabetic cohorts in order to fully assess the benefits of PDE5i in this group of patients.
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Affiliation(s)
- Agnieszka Swiecicka
- Department of Basic and Clinical Sciences, University of Nicosia Medical School, Nicosia, Cyprus
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4
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Dynamic Regulation of Cysteine Oxidation and Phosphorylation in Myocardial Ischemia-Reperfusion Injury. Cells 2021; 10:cells10092388. [PMID: 34572037 PMCID: PMC8469016 DOI: 10.3390/cells10092388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 02/02/2023] Open
Abstract
Myocardial ischemia-reperfusion (I/R) injury significantly alters heart function following infarct and increases the risk of heart failure. Many studies have sought to preserve irreplaceable myocardium, termed cardioprotection, but few, if any, treatments have yielded a substantial reduction in clinical I/R injury. More research is needed to fully understand the molecular pathways that govern cardioprotection. Redox mechanisms, specifically cysteine oxidations, are acute and key regulators of molecular signaling cascades mediated by kinases. Here, we review the role of reactive oxygen species in modifying cysteine residues and how these modifications affect kinase function to impact cardioprotection. This exciting area of research may provide novel insight into mechanisms and likely lead to new treatments for I/R injury.
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Frankenreiter S, Bednarczyk P, Kniess A, Bork NI, Straubinger J, Koprowski P, Wrzosek A, Mohr E, Logan A, Murphy MP, Gawaz M, Krieg T, Szewczyk A, Nikolaev VO, Ruth P, Lukowski R. cGMP-Elevating Compounds and Ischemic Conditioning Provide Cardioprotection Against Ischemia and Reperfusion Injury via Cardiomyocyte-Specific BK Channels. Circulation 2017; 136:2337-2355. [PMID: 29051185 DOI: 10.1161/circulationaha.117.028723] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 10/02/2017] [Indexed: 11/16/2022]
Abstract
BACKGROUND The nitric oxide-sensitive guanylyl cyclase/cGMP-dependent protein kinase type I signaling pathway can afford protection against the ischemia/reperfusion injury that occurs during myocardial infarction. Reportedly, voltage and Ca2+-activated K+ channels of the BK type are stimulated by cGMP/cGMP-dependent protein kinase type I, and recent ex vivo studies implicated that increased BK activity favors the survival of the myocardium at ischemia/reperfusion. It remains unclear, however, whether the molecular events downstream of cGMP involve BK channels present in cardiomyocytes or in other cardiac cell types. METHODS Gene-targeted mice with a cardiomyocyte- or smooth muscle cell-specific deletion of the BK (CMBK or SMBK knockouts) were subjected to the open-chest model of myocardial infarction. Infarct sizes of the conditional mutants were compared with litter-matched controls, global BK knockout, and wild-type mice. Cardiac damage was assessed after mechanical conditioning or pharmacological stimulation of the cGMP pathway and by using direct modulators of BK. Long-term outcome was studied with respect to heart functions and cardiac fibrosis in a chronic myocardial infarction model. RESULTS Global BK knockouts and CMBK knockouts, in contrast with SMBK knockouts, exhibited significantly larger infarct sizes compared with their respective controls. Ablation of CMBK resulted in higher serum levels of cardiac troponin I and elevated amounts of reactive oxygen species, lower phosphorylated extracellular receptor kinase and phosphorylated AKT levels and an increase in myocardial apoptosis. Moreover, CMBK was required to allow beneficial effects of both nitric oxide-sensitive guanylyl cyclase activation and inhibition of the cGMP-degrading phosphodiesterase-5, ischemic preconditioning, and postconditioning regimens. To this end, after 4 weeks of reperfusion, fibrotic tissue increased and myocardial strain echocardiography was significantly compromised in CMBK-deficient mice. CONCLUSIONS Lack of CMBK channels renders the heart more susceptible to ischemia/reperfusion injury, whereas the pathological events elicited by ischemia/reperfusion do not involve BK in vascular smooth muscle cells. BK seems to permit the protective effects triggered by cinaciguat, riociguat, and different phosphodiesterase-5 inhibitors and beneficial actions of ischemic preconditioning and ischemic postconditioning by a mechanism stemming primarily from cardiomyocytes. This study establishes mitochondrial CMBK channels as a promising target for limiting acute cardiac damage and adverse long-term events that occur after myocardial infarction.
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Affiliation(s)
- Sandra Frankenreiter
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
| | - Piotr Bednarczyk
- Department of Biophysics, Warsaw University of Life Sciences, Poland (P.B.)
| | - Angelina Kniess
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
| | - Nadja I Bork
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (N.I.B., V.O.N.)
| | - Julia Straubinger
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
| | - Piotr Koprowski
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland (P.K., A.W., A.S.)
| | - Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland (P.K., A.W., A.S.)
| | - Eva Mohr
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
| | | | | | - Meinrad Gawaz
- University of Cambridge, Cambridge Biomedical Campus, United Kingdom. Internal Medicine III, Cardiology and Cardiovascular Medicine, University Hospital Tuebingen, Germany (M.G.)
| | | | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Warsaw, Poland (P.K., A.W., A.S.)
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Germany (N.I.B., V.O.N.)
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Germany (S.F., A.K., J.S., E.M., P.R., R.L.)
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sGC-cGMP-PKG pathway stimulation protects the healthy but not the failing right ventricle of rats against ischemia and reperfusion injury. Int J Cardiol 2016; 223:674-680. [PMID: 27568988 DOI: 10.1016/j.ijcard.2016.08.264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/16/2016] [Accepted: 08/15/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND To investigate whether modulation of the sGC-cGMP-PKG pathway protects against ischemia and reperfusion injury in the healthy and the failing right ventricle (RV). METHODS Hearts from male Wistar rats with a healthy RV (n=39) or a hypertrophic and failing RV induced by pulmonary trunk banding (n=57) were isolated and perfused in a pressure-controlled modified Langendorff setup. The isolated hearts were randomized to control, ischemic preconditioning (IPC, 2×5min of global ischemia), a phosphodiesterase-5 (PDE5) inhibitor vardenafil (66nM) alone and in combination with a cGMP-dependent protein kinase (PKG) blocker KT 5823 (1μM). Failing hearts were exposed to the same protocols and to soluble guanylate cyclase stimulation/activation, and phosphodiesterase 9 inhibition. All interventions were followed by 40min of global ischemia and 120min of reperfusion. The effects on the RV were evaluated by measurement of the infarct size/area-at-risk ratio (IS/AAR). RESULTS In healthy hearts, IPC and pharmacological preconditioning with vardenafil reduced RV infarct size. PKG blockade by KT-5823 did not alter infarct size per se but abolished the cardioprotective effect of vardenafil. In the hypertrophic and failing hearts, none of the conditioning strategies altered RV infarct size. CONCLUSION PDE-5 inhibition by vardenafil protects the healthy right ventricle against ischemia and reperfusion injury by a PKG dependent mechanism. Neither ischemic preconditioning nor pharmacologic stimulation of the sGC-cGMP-PKG pathway induces cardioprotection in the hypertrophic and failing RV.
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7
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Anderson SG, Hutchings DC, Woodward M, Rahimi K, Rutter MK, Kirby M, Hackett G, Trafford AW, Heald AH. Phosphodiesterase type-5 inhibitor use in type 2 diabetes is associated with a reduction in all-cause mortality. Heart 2016; 102:1750-1756. [PMID: 27465053 PMCID: PMC5099221 DOI: 10.1136/heartjnl-2015-309223] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/23/2016] [Indexed: 12/18/2022] Open
Abstract
Objective Experimental evidence has shown potential cardioprotective actions of phosphodiesterase type-5 inhibitors (PDE5is). We investigated whether PDE5i use in patients with type 2 diabetes, with high-attendant cardiovascular risk, was associated with altered mortality in a retrospective cohort study. Research design and methods Between January 2007 and May 2015, 5956 men aged 40–89 years diagnosed with type 2 diabetes before 2007 were identified from anonymised electronic health records of 42 general practices in Cheshire, UK, and were followed for 7.5 years. HRs from multivariable survival (accelerated failure time, Weibull) models were used to describe the association between on-demand PDE5i use and all-cause mortality. Results Compared with non-users, men who are prescribed PDE5is (n=1359) experienced lower percentage of deaths during follow-up (19.1% vs 23.8%) and lower risk of all-cause mortality (unadjusted HR=0.69 (95% CI: 0.64 to 0.79); p<0.001)). The reduction in risk of mortality (HR=0.54 (0.36 to 0.80); p=0.002) remained after adjusting for age, estimated glomerular filtration rate, smoking status, prior cerebrovascular accident (CVA) hypertension, prior myocardial infarction (MI), systolic blood pressure, use of statin, metformin, aspirin and β-blocker medication. PDE5i users had lower rates of incident MI (incidence rate ratio (0.62 (0.49 to 0.80), p<0.0001) with lower mortality (25.7% vs 40.1% deaths; age-adjusted HR=0.60 (0.54 to 0.69); p=0.001) compared with non-users within this subgroup. Conclusion In a population of men with type 2 diabetes, use of PDE5is was associated with lower risk of overall mortality and mortality in those with a history of acute MI.
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Affiliation(s)
- Simon G Anderson
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK The George Institute for Global Health, Oxford Martin School, University of Oxford, Oxford, UK
| | - David C Hutchings
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Mark Woodward
- The George Institute for Global Health, Oxford Martin School, University of Oxford, Oxford, UK The George Institute for Global Health, University of Sydney, Australia
| | - Kazem Rahimi
- The George Institute for Global Health, Oxford Martin School, University of Oxford, Oxford, UK
| | - Martin K Rutter
- Manchester Diabetes Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester, UK
| | - Mike Kirby
- The Centre for Research in Primary & Community Care, University of Hertfordshire, Hatfield, UK
| | - Geoff Hackett
- Department of Urology, Good Hope Hospital, Sutton Coldfield, UK
| | - Andrew W Trafford
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Adrian H Heald
- School of Medicine, and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK Leighton Hospital, Crewe, UK
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Lougiakis N, Papapetropoulos A, Gikas E, Toumpas S, Efentakis P, Wedmann R, Zoga A, Zhou Z, Iliodromitis EK, Skaltsounis AL, Filipovic MR, Pouli N, Marakos P, Andreadou I. Synthesis and Pharmacological Evaluation of Novel Adenine–Hydrogen Sulfide Slow Release Hybrids Designed as Multitarget Cardioprotective Agents. J Med Chem 2016; 59:1776-90. [DOI: 10.1021/acs.jmedchem.5b01223] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Nikolaos Lougiakis
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Andreas Papapetropoulos
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Evangelos Gikas
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Spyridon Toumpas
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Panagiotis Efentakis
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Rudolf Wedmann
- Department
of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Anastasia Zoga
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
- Second University
Department of Cardiology, Medical School, Attikon General Hospital,
National and Kapodistrian University of Athens, 12462, Athens, Greece
| | - Zhongmin Zhou
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Efstathios K. Iliodromitis
- Second University
Department of Cardiology, Medical School, Attikon General Hospital,
National and Kapodistrian University of Athens, 12462, Athens, Greece
| | - Alexios-Leandros Skaltsounis
- Department
of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Milos R. Filipovic
- Department
of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nuremberg, 91054 Erlangen, Germany
| | - Nicole Pouli
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Panagiotis Marakos
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
| | - Ioanna Andreadou
- Department
of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, 15771, Athens, Greece
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Andreadou I, Iliodromitis EK, Szabo C, Papapetropoulos A. Hydrogen sulfide and PKG in ischemia-reperfusion injury: sources, signaling, accelerators and brakes. Basic Res Cardiol 2015; 110:510. [PMID: 26318600 PMCID: PMC4667708 DOI: 10.1007/s00395-015-0510-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/12/2015] [Accepted: 08/26/2015] [Indexed: 12/14/2022]
Abstract
Over the past decade, hydrogen sulfide has emerged as an important cardioprotective molecule with potential for clinical applications. Although several pathways have been proposed to mediate the beneficial effects of H2S, the NO/cGMP axis has attracted significant attention. Recent evidence has suggested that cGMP-dependent protein kinase can lie both downstream and upstream of H2S. The current literature on this topic is reviewed and data from recent studies are integrated to propose a unifying model.
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Affiliation(s)
| | - Efstathios K. Iliodromitis
- Faculty of Medicine, Second Department of Cardiology, Attikon University Hospital, University of Athens, Athens, Greece
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Andreas Papapetropoulos
- Faculty of Pharmacy, University of Athens, Athens, Greece
- Faculty of Medicine, First Department of Critical Care and Pulmonary Services, Evangelismos Hospital, University of Athens, Athens, Greece
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Wanka H, Staar D, Lutze P, Peters B, Hildebrandt J, Beck T, Bäumgen I, Albers A, Krieg T, Zimmermann K, Sczodrok J, Schäfer S, Hoffmann S, Peters J. Anti-necrotic and cardioprotective effects of a cytosolic renin isoform under ischemia-related conditions. J Mol Med (Berl) 2015; 94:61-9. [DOI: 10.1007/s00109-015-1321-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 12/31/2022]
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Riociguat reduces infarct size and post-infarct heart failure in mouse hearts: insights from MRI/PET imaging. PLoS One 2013; 8:e83910. [PMID: 24391843 PMCID: PMC3877128 DOI: 10.1371/journal.pone.0083910] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/08/2013] [Indexed: 11/19/2022] Open
Abstract
AIM Stimulation of the nitric oxide (NO)--soluble guanylate (sGC)--protein kinase G (PKG) pathway confers protection against acute ischaemia/reperfusion injury, but more chronic effects in reducing post-myocardial infarction (MI) heart failure are less defined. The aim of this study was to not only determine whether the sGC stimulator riociguat reduces infarct size but also whether it protects against the development of post-MI heart failure. METHODS AND RESULTS Mice were subjected to 30 min ischaemia via ligation of the left main coronary artery to induce MI and either placebo or riociguat (1.2 µmol/l) were given as a bolus 5 min before and 5 min after onset of reperfusion. After 24 hours, both, late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) and (18)F-FDG-positron emission tomography (PET) were performed to determine infarct size. In the riociguat-treated mice, the resulting infarct size was smaller (8.5 ± 2.5% of total LV mass vs. 21.8% ± 1.7%. in controls, p = 0.005) and LV systolic function analysed by MRI was better preserved (60.1% ± 3.4% of preischaemic vs. 44.2% ± 3.1% in controls, p = 0.005). After 28 days, LV systolic function by echocardiography treated group was still better preserved (63.5% ± 3.2% vs. 48.2% ± 2.2% in control, p = 0.004). CONCLUSION Taken together, mice treated acutely at the onset of reperfusion with the sGC stimulator riociguat have smaller infarct size and better long-term preservation of LV systolic function. These findings suggest that sGC stimulation during reperfusion therapy may be a powerful therapeutic treatment strategy for preventing post-MI heart failure.
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12
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Pharmacological postconditioning by bolus injection of phosphodiesterase-5 inhibitors vardenafil and sildenafil. Mol Cell Biochem 2013; 379:43-9. [PMID: 23532676 DOI: 10.1007/s11010-013-1625-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 03/21/2013] [Indexed: 12/31/2022]
Abstract
Postconditioning enables cardioprotection against ischemia/reperfusion injury either by application of short, repetitive ischemic periods or by pharmacological intervention prior to reperfusion. Pharmacological postconditioning has been described for phosphodiesterase-5 inhibitors when the substances were applied as a permanent infusion. For clinical purposes, application of a bolus is more convenient. In a rat heart in situ model of ischemia reperfusion vardenafil or sildenafil were applied as a bolus prior to reperfusion. Cardioprotective effects were found over a broad dosage range. In accordance with current hypotheses on pharmacological postconditioning signaling, the protective effect was mediated by extracellular signal-regulated kinase and protein kinase C pathway. Interestingly, the extent of protection was independent of the concentration applied for both substances. Full protection comparable to ischemic postconditioning was reached with half-maximal human equivalence dose. In contrast, mean arterial pressure dropped upon bolus application in a dose-dependent manner. Taken together, the current study extends previous findings obtained in a permanent infusion model to bolus application. This is an important step toward clinical application of pharmacological postconditioning with sildenafil and vardenafil, especially because the beneficial effects were proven for concentrations with reduced hemodynamic side effects compared to the dosage applied for erectile dysfunction treatment.
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13
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Chen WS, Li XQ, Cao W, Xiao X, Dong L, Zhang JZ. Vardenafil ameliorates calcium mobilization in pulmonary artery smooth muscle cells from hypoxic pulmonary hypertensive mice. Arch Med Res 2012; 43:265-73. [PMID: 22704850 DOI: 10.1016/j.arcmed.2012.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Accepted: 04/30/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND AND AIMS Vardenafil has been found to be potent in pulmonary hypertension; however, the underlying mechanisms remain poorly understood. To address this issue, we investigated the underlying mechanisms of vardenafil in the contribution of Ca(2+) signaling and mobilization in modifying vasoconstriction of pulmonary arteries in hypoxic mice. METHODS Hemodynamic measurements and morphological studies were performed. Muscle tension was measured by PowerLab system. I(Ca,L) was recorded using a perforated patch-clamp technique. [Ca(2+)](i) was measured using a fluorescence imaging system. RESULTS Vardenafil greatly inhibited RVSP increases, RV hypertrophy and ameliorated pulmonary artery remodeling in response to chronic hypoxia. Membrane depolarization following 50 mM high K(+)-caused muscle contraction significantly decreased from 101.7 ± 10.1 in the hypoxia group to 81.8 ± 5.0 mg in hypoxia plus vardenafil arteries. Fifty mM high K(+)-elicited increase [Ca(2+)](i) was markedly decreased from 610.6 ± 71.8 in hypoxia cells to 400.3 ± 47.2 nM in hypoxia plus vardenafil cells. Application of vardenafil greatly inhibited the density of I(Ca,L) by 37.7% compared with that in the hypoxia group. Administration of 1 μM phenylephrine to stimulate α(1)-adrenergic receptor resulted in a smaller increase in [Ca(2+)](i) in hypoxia plus vardenafil cells than that in hypoxia cells. One hundred μM ATP-mediated increase in [Ca(2+)](i) was also inhibited in vardenafil-hypoxia group (from 625.8 ± 62.3 to 390.9 ± 38.1 nM), suggesting that internal calcium reserves contribute to neurotransmitter-induced Ca(2+) release from the SR through IP(3)Rs in PASMCs. CONCLUSIONS Vardenafil may effectively block Ca(2+) influx through L-type Ca(2+) channel and inhibit the Ca(2+) release from SR through IP(3)Rs, thus enhancing its vasorelaxation of pulmonary arteries under hypoxia conditions.
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Affiliation(s)
- Wen-Sheng Chen
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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Gerczuk PZ, Kloner RA. An update on cardioprotection: a review of the latest adjunctive therapies to limit myocardial infarction size in clinical trials. J Am Coll Cardiol 2012; 59:969-78. [PMID: 22402067 DOI: 10.1016/j.jacc.2011.07.054] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 06/13/2011] [Accepted: 07/19/2011] [Indexed: 12/13/2022]
Abstract
Acute myocardial infarction (AMI) with subsequent left ventricular dysfunction and heart failure continues to be a major cause of morbidity and mortality in the Western world. Rapid advances in the treatment of AMI, mainly through timely reperfusion, have substantially improved outcomes in patients presenting with acute coronary syndrome and particularly ST-segment elevation myocardial infarction. A vast amount of research, both translational and clinical, has been published on various pharmacological and interventional techniques to prevent myocardial cell death during the time of ischemia and subsequent reperfusion. Several methods of cardioprotection have shown the ability to limit myocardial infarction size in clinical trials. Examples of interventional techniques that have proven beneficial are ischemic post-conditioning and remote ischemic per-conditioning, both of which can reduce infarction size. Lowering core body temperature with cold saline infusion and cooling catheters have also been shown to be effective in certain circumstances. The most promising pharmaceutical cardioprotective agents at this time appear to be adenosine, atrial natriuretic peptide, and cyclosporine, with other potentially effective medications in the pipeline. Additional pre-clinical and clinical research is needed to further investigate newer cardioprotective strategies to continue the current trend of improving outcomes following AMI.
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Affiliation(s)
- Paul Z Gerczuk
- Heart Institute, Good Samaritan Hospital, Wilshire Boulevard, Los Angeles, CA 90017, USA
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Grube K, Rüdebusch J, Xu Z, Böckenholt T, Methner C, Müller T, Cuello F, Zimmermann K, Yang X, Felix SB, Cohen MV, Downey JM, Krieg T. Evidence for an intracellular localization of the adenosine A2B receptor in rat cardiomyocytes. Basic Res Cardiol 2011; 106:385-96. [PMID: 21246204 DOI: 10.1007/s00395-011-0151-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 12/17/2010] [Accepted: 01/03/2011] [Indexed: 11/26/2022]
Abstract
Protection achieved by ischemic preconditioning is dependent on A(2B) adenosine receptors (A(2B)AR) in rabbit and mouse hearts and, predictably, an A(2B)AR agonist protects them. But it is controversial whether cardiomyocytes themselves actually express A(2B)AR. The present study tested whether A(2B)AR could be demonstrated on rat cardiomyocytes. Isolated rat hearts experienced 30 min of ischemia and 120 min of reperfusion. The highly selective, cell-permeant A(2B)AR agonist BAY60-6583 (500 nM) infused at reperfusion reduced infarct size from 40.4 ± 2.0% of the risk zone in control hearts to 19.9 ± 2.8% indicating that A(2B)AR are protective in rat heart as well. Furthermore, BAY60-6583 reduced calcium-induced mitochondrial permeability transition in isolated rat cardiomyocytes. A(2B)AR protein could be demonstrated in isolated cardiomyocytes by western blotting. In addition, message for A(2B)AR was found in individual cardiomyocytes using quantitative RT-PCR. Surprisingly, immunofluorescence microscopy did not show A(2B)AR on the cardiomyocyte's sarcolemma but rather at intracellular sites. Co-staining with MitoTracker Red in isolated cardiomyocytes revealed A(2B)AR are localized to mitochondria. Western blot analysis of a mitochondrial fraction from either rat heart biopsies or isolated cardiomyocytes revealed a strong A(2B)AR band. Thus, the present study demonstrates that activation of A(2B)AR is strongly cardioprotective in rat heart and suppresses transition pores in isolated cardiomyocytes, and A(2B)AR are expressed in individual cardiomyocytes. However, surprisingly, A(2B)AR are present in or near mitochondria rather than on the sarcolemma as are other adenosine receptors. Because A(2B)AR signaling is thought to result in inhibition of mitochondrial transition pores, this convenient location may be important.
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Affiliation(s)
- Karina Grube
- Department of Cardiology, Ernst-Moritz-Arndt University, Greifswald, Germany
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Cohen MV, Yang XM, Liu Y, Solenkova NV, Downey JM. Cardioprotective PKG-independent NO signaling at reperfusion. Am J Physiol Heart Circ Physiol 2010; 299:H2028-36. [PMID: 20852051 DOI: 10.1152/ajpheart.00527.2010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell models of ischemic preconditioning (IPC) indicate nitric oxide (NO) is involved in protection accruing during reoxygenation but disagree whether it acts through PKG. Using a more relevant intact heart model, we studied isolated rabbit hearts subjected to 30-min coronary artery occlusion/120-min reperfusion. We previously found protection from PKG activator 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (CPT-cGMP) at reperfusion was blocked by A(2b) adenosine receptor (A(2b)AR), ERK, or phosphatidylinositol 3-kinase (PI3-kinase) blockers. In this investigation A(2b)AR agonist BAY 60-6583 or CPT-cGMP at reperfusion reduced infarction comparably to IPC. Their protection was abrogated by N(ω)-nitro-l-arginine methyl ester (l-NAME), suggesting a PKG-independent NO synthase in IPC's mediator pathway downstream of PKG and A(2b)AR. NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) at reperfusion also protected. This protection was not blocked by PI3-kinase inhibitor wortmannin or ERK antagonist PD-98059, suggesting NO acted downstream of these kinases. Protection from SNAP was not affected by mitochondrial ATP-sensitive K(+) channel closer 5-hydroxydecanoate, PKC antagonist chelerythrine, reactive oxygen species scavenger N-2-mercaptopropionylglycine, or soluble guanylyl cyclase antagonist 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Absence of ODQ effect indicated NO was acting independently of PKG. BAY 58-2667, a soluble guanylyl cyclase activator, was protective, and l-NAME blocked its infarct-sparing effect, indicating a second signaling event dependent on NO generation but independent of PKG. SB216763, a blocker of glycogen synthase kinase-3β (GSK-3β), decreased infarct size, and its infarct-sparing effect was not affected by l-NAME, suggesting GSK-3β acted downstream or independently of NO. Hence, NO signaling occurs in IPC's mediator pathway downstream of Akt and ERK, and its protection is independent of PKG.
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Affiliation(s)
- Michael V Cohen
- Department of Physiology, University of South Alabama College of Medicine, Mobile, Alabama 36688, USA.
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Madhani M, Hall AR, Cuello F, Charles RL, Burgoyne JR, Fuller W, Hobbs AJ, Shattock MJ, Eaton P. Phospholemman Ser69 phosphorylation contributes to sildenafil-induced cardioprotection against reperfusion injury. Am J Physiol Heart Circ Physiol 2010; 299:H827-36. [PMID: 20543084 PMCID: PMC2944484 DOI: 10.1152/ajpheart.00129.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The phosphodiesterase type-5 inhibitor sildenafil has powerful cardioprotective effects against ischemia-reperfusion injury. PKG-mediated signaling has been implicated in this protection, although the mechanism and the downstream targets of this kinase remain to be fully elucidated. In this study we assessed the role of phospholemman (PLM) phosphorylation, which activates the Na+/K+-ATPase, in cardioprotection afforded by sildenafil administered during reperfusion. Isolated perfused mouse hearts were optimally protected against infarction (indexed by tetrazolium staining) by 0.1 μM sildenafil treatment during the first 10 min of reperfusion. Extended sildenafil treatment (30, 60, or 120 min at reperfusion) did not alter the degree of protection provided. This protection was PKG dependent, since it was blocked by KT-5823. Western blot analysis using phosphospecific antibodies to PLM showed that sildenafil at reperfusion did not modulate PLM Ser63 or Ser68 phosphorylation but significantly increased Ser69 phosphorylation. The treatment of isolated rat ventricular myocytes with sildenafil or 8-bromo-cGMP (PKG agonist) enhanced PLM Ser69 phosphorylation, which was bisindolylmaleimide (PKC inhibitor) sensitive. Patch-clamp studies showed that sildenafil treatment also activated the Na+/K+-ATPase, which is anticipated in light of PLM Ser69 phosphorylation. Na+/K+-ATPase activation during reperfusion would attenuate Na+ overload at this time, providing a molecular explanation of how sildenafil guards against injury at this time. Indeed, using flame photometry and rubidium uptake into isolated mouse hearts, we found that sildenafil enhanced Na+/K+-ATPase activity during reperfusion. In this study we provide a molecular explanation of how sildenafil guards against myocardial injury during postischemic reperfusion.
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Affiliation(s)
- Melanie Madhani
- Cardiovascular Division, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
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Methner C, Donat U, Felix SB, Krieg T. Cardioprotection of bradykinin at reperfusion involves transactivation of the epidermal growth factor receptor via matrix metalloproteinase-8. Acta Physiol (Oxf) 2009; 197:265-71. [PMID: 19583703 DOI: 10.1111/j.1748-1716.2009.02018.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The endogenous autacoid bradykinin (BK) reportedly reduces myocardial infarct size when given exogenously at reperfusion. Muscarinic and opioid G-protein-coupled receptors are equally protective and have been shown to couple through a matrix metalloproteinase (MMP)-dependent transactivation of the epidermal growth factor receptor (EGFR). Here we test whether BK protects the rat heart through the EGFR by an MMP-dependent pathway. METHODS Infarct size was measured in isolated perfused rat hearts undergoing 30 min regional ischaemia followed by 120 min reperfusion. In additional studies HL-1 cardiomyocytes were loaded with tetramethylrhodamine ethyl to measure their mitochondrial membrane potential (Psim). Adding the calcium ionophore calcimycin, causes Psim-collapse presumably due to calcium-induced mitochondrial permeability transition. RESULTS As expected, BK (100 nmol L(-1)) started 5 min prior to reperfusion reduced infarct size from 38.9 +/- 2.0% of the ischaemic zone in control hearts to 22.2 +/- 3.3% (P < 0.001). Co-infusing the EGFR inhibitor AG1478, the broad-spectrum MMP-inhibitor GM6001, or a highly selective MMP-8 inhibitor abolished BK's protection, thus suggesting an MMP-8-dependent EGFR transactivation in the signalling. Eighty minutes of exposure to calcimycin reduced the mean cell fluorescence to 37.4 +/- 1.8% of untreated cells while BK could partly preserve the fluorescence and, hence, protect the cells (50.5 +/- 2.3%, P < 0.001). The BK-induced mitochondrial protection could again be blocked by AG1478, GM6001 and MMP-8 inhibitor. Finally, Western blotting revealed that BK's protection was correlated with increased phosphorylation of EGFR and its downstream target Akt. CONCLUSION These results indicate that BK at reperfusion triggers its protective signalling pathway through MMP-8-dependent transactivation of the EGFR.
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Affiliation(s)
- C Methner
- Department of Cardiology, Ernst-Moritz-Arndt University, Greifswald, Germany
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Erol B, Tokgoz H, Hanci V, Bektas S, Akduman B, Yencilek F, Mungan G, Mungan A. Vardenafil Reduces Testicular Damage Following Ischemia/Reperfusion Injury in Rats. Kaohsiung J Med Sci 2009; 25:374-80. [DOI: 10.1016/s1607-551x(09)70530-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Abstract
A growing body of animal studies provides evidence for potential cardioprotective effects of inhibitors of the enzyme phosphodiesterase isoform 5. Infarct size reduction by administration of phosphodiesterase 5 inhibitors was described in various experimental models of ischaemia and reperfusion. Furthermore, potential beneficial effects were demonstrated in experimental models of congestive heart failure and left ventricular hypertrophy. Some of the observed effects resemble the basic mechanisms of ischaemic pre-conditioning, mimicking both acute and delayed effects. Other effects may be due to action on systemic and cardiac haemodynamics. Mechanisms and signalling pathways, characterized in some of the experimental models, appear to be complex: for instance, the rate of cyclic guanosine monophosphate (cGMP) synthesis and the functional compartmentalization of intracellular cGMP metabolism as well as interaction with ss-adrenergic and nitric oxide signalling may influence effects in different experimental settings. In this review, we discuss mechanisms, signalling pathways, and experimental limitations and touch on considerations for translation into potentially useful applications in the clinical arena.
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Affiliation(s)
- Thorsten Reffelmann
- Klinik und Poliklinik für Innere Medizin B, Universitätsklinikum der Ernst-Moritz-Arndt-Universität Greifswald, Friedrich-Löffler-Str. 23 a, 17475 Greifswald, Germany.
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Krieg T, Liu Y, Rütz T, Methner C, Yang XM, Dost T, Felix SB, Stasch JP, Cohen MV, Downey JM. BAY 58-2667, a nitric oxide-independent guanylyl cyclase activator, pharmacologically post-conditions rabbit and rat hearts. Eur Heart J 2009; 30:1607-13. [PMID: 19406872 DOI: 10.1093/eurheartj/ehp143] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS BAY 58-2667 (BAY-58) directly activates soluble guanylyl cyclase without tolerance in a nitric oxide (NO)-independent manner, and its haemodynamic effect is similar to that of nitroglycerin. We tested whether BAY-58 could make both rabbit and rat hearts resistant to infarction when given at the end of an ischaemic insult. METHODS AND RESULTS All hearts were exposed to 30 min regional ischaemia followed by 120-(isolated hearts) or 180-(in situ hearts) min reperfusion. BAY-58 (1-50 nM) infused for 60 min starting 5 min before reperfusion significantly reduced infarction from 33.0 +/- 3.2% in control isolated rabbit hearts to 9.5-12.7% (P < 0.05). In a more clinically relevant in situ rabbit model, infarct size was similarly reduced with a loading dose of 53.6 microg/kg followed by a 60 min infusion of 1.25 microg/kg/min (41.1 +/- 3.1% infarction in control hearts to 16.0 +/- 4.4% in treated hearts, P < 0.05). BAY-58 similarly decreased infarction in the isolated rat heart, and protection was abolished by co-treatment with a protein kinase G (PKG) antagonist, or a mitochondrial K(ATP) channel antagonist. Conversely, N(omega)-nitro-L-arginine-methyl-ester-hydrochloride, a NO-synthase inhibitor, failed to block BAY-58's ability to decrease infarction, consistent with the latter's putative NO-independent activation of PKG. Finally, BAY-58 increased myocardial cGMP content in reperfused hearts while cAMP was unchanged. CONCLUSION When applied at reperfusion, BAY-58 is an effective cardioprotective agent with a mechanism similar to that of ischaemic pre-conditioning and, hence, should be a candidate for treatment of acute myocardial infarction in man.
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Affiliation(s)
- Thomas Krieg
- Department of Cardiology, Ernst-Moritz-Arndt University, Loefflerstr. 23, 17487 Greifswald, Germany.
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Das A, Xi L, Kukreja RC. Protein kinase G-dependent cardioprotective mechanism of phosphodiesterase-5 inhibition involves phosphorylation of ERK and GSK3beta. J Biol Chem 2008; 283:29572-85. [PMID: 18723505 DOI: 10.1074/jbc.m801547200] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sildenafil, a potent inhibitor of phosphodiesterase-5 (PDE-5) induces powerful protection against myocardial ischemia-reperfusion injury. PDE-5 inhibition increases cGMP levels that activate cGMP-dependent protein kinase (PKG). However, the cause and effect relationship of PKG in sildenafil-induced cardioprotection and the downstream targets of PKG remain unclear. Adult ventricular myocytes were treated with sildenafil and subjected to simulated ischemia and reoxygenation. Sildenafil treatment significantly decreased cardiomyocyte necrosis and apoptosis. The PKG inhibitors, KT5823, guanosine 3',5'-cyclic monophosphorothioate, 8-(4-chloro-phenylthio) (R(p)-8-pCPT-cGMPs), or DT-2 blocked the anti-necrotic and anti-apoptotic effect of sildenafil. Selective knockdown of PKG in cardiomyocytes with adenoviral vector containing short hairpin RNA of PKG also abolished sildenafil-induced protection. Furthermore, intra-coronary infusion of sildenafil in Langendorff-isolated mouse hearts prior to ischemia-reperfusion significantly reduced myocardial infarct size after 20 min ischemia and 30 min reperfusion, which was abrogated by KT5823. Sildenafil significantly increased PKG activity in intact hearts and cardiomyocytes. Sildenafil also enhanced the Bcl-2/Bax ratio, phosphorylation of Akt, ERK1/2, and glycogen synthase kinase 3beta. All these changes (except Akt phosphorylation) were significantly blocked by KT5823 and short hairpin RNA of PKG. These studies provide the first evidence for an essential role of PKG in sildenafil-induced cardioprotection. Moreover, our results demonstrate that sildenafil activates a PKG-dependent novel signaling cascade that involves activation of ERK and inhibition of glycogen synthase kinase 3beta leading to cytoprotection.
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Affiliation(s)
- Anindita Das
- Division of Cardiology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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Kuno A, Solenkova NV, Solodushko V, Dost T, Liu Y, Yang XM, Cohen MV, Downey JM. Infarct limitation by a protein kinase G activator at reperfusion in rabbit hearts is dependent on sensitizing the heart to A2b agonists by protein kinase C. Am J Physiol Heart Circ Physiol 2008; 295:H1288-H1295. [PMID: 18660452 DOI: 10.1152/ajpheart.00209.2008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PKG activator 8-(4-chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (CPT) at reperfusion protects ischemic hearts, but the mechanism is unknown. We recently proposed that in preconditioned hearts PKC lowers the threshold for adenosine to initiate signaling from low-affinity A2b receptors during early reperfusion thus allowing endogenous adenosine to activate survival kinases phosphatidylinositol 3-kinase (PI3K) and ERK. We tested whether CPT might also sensitize A2b receptors to adenosine. CPT (10 microM) during the first minutes of reperfusion markedly reduced infarction in isolated rabbit hearts undergoing 30-min regional ischemia/2-h reperfusion, and salvage was blocked by MRS 1754, an A2b-selective antagonist. Coadministration of wortmannin (PI3K inhibitor) or PD-98059 (MEK1/2 and therefore ERK1/2 inhibitor) also blocked protection. In nonischemic hearts, 10-min infusion of CPT did not change phosphorylation of Akt or ERK1/2. Neither did a subthreshold dose (2.5 nM) of the nonselective but A2b-potent receptor agonist 5'-(N-ethylcarboxamido)adenosine (NECA). However, when 2.5 nM NECA was combined with 10 microM CPT, both phospho-Akt and phospho-ERK1/2 significantly increased, indicating CPT had lowered the threshold for A2b-dependent signaling. The PKC antagonist chelerythrine blocked this phosphorylation induced by CPT + NECA. Chelerythrine also blocked the anti-infarct effect of CPT as did nonselective (glibenclamide) and mitochondrial-selective (5-hydroxydecanoate) K(ATP) channel blockers. A free radical scavenger, N-(2-mercaptopropionyl)glycine, also blocked CPT protection. We propose CPT targets PKG, which activates PKC through mitochondrial K(ATP) channel (mitoKATP)-dependent redox signaling, a sequence mimicking that already documented in preconditioning. Activated PKC then augments sensitivity of normally low-affinity cardiac adenosine A2b receptors so endogenous adenosine can protect by activating Akt and ERK.
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Affiliation(s)
- Atsushi Kuno
- Department of Physiology, University of South Alabama, College of Medicine, Mobile, AL 36688, USA
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