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Tikhomirov R, Oakley RH, Anderson C, Xiang Y, Al-Othman S, Smith M, Yaar S, Torre E, Li J, Wilson LR, Goulding DR, Donaldson I, Harno E, Soattin L, Shiels HA, Morris GM, Zhang H, Boyett MR, Cidlowski JA, Mesirca P, Mangoni ME, D'Souza A. Cardiac GR Mediates the Diurnal Rhythm in Ventricular Arrhythmia Susceptibility. Circ Res 2024; 134:1306-1326. [PMID: 38533639 PMCID: PMC11081863 DOI: 10.1161/circresaha.123.323464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 02/15/2024] [Accepted: 03/13/2024] [Indexed: 03/28/2024]
Abstract
BACKGROUND Ventricular arrhythmias (VAs) demonstrate a prominent day-night rhythm, commonly presenting in the morning. Transcriptional rhythms in cardiac ion channels accompany this phenomenon, but their role in the morning vulnerability to VAs and the underlying mechanisms are not understood. We investigated the recruitment of transcription factors that underpins transcriptional rhythms in ion channels and assessed whether this mechanism was pertinent to the heart's intrinsic diurnal susceptibility to VA. METHODS AND RESULTS Assay for transposase-accessible chromatin with sequencing performed in mouse ventricular myocyte nuclei at the beginning of the animals' inactive (ZT0) and active (ZT12) periods revealed differentially accessible chromatin sites annotating to rhythmically transcribed ion channels and distinct transcription factor binding motifs in these regions. Notably, motif enrichment for the glucocorticoid receptor (GR; transcriptional effector of corticosteroid signaling) in open chromatin profiles at ZT12 was observed, in line with the well-recognized ZT12 peak in circulating corticosteroids. Molecular, electrophysiological, and in silico biophysically-detailed modeling approaches demonstrated GR-mediated transcriptional control of ion channels (including Scn5a underlying the cardiac Na+ current, Kcnh2 underlying the rapid delayed rectifier K+ current, and Gja1 responsible for electrical coupling) and their contribution to the day-night rhythm in the vulnerability to VA. Strikingly, both pharmacological block of GR and cardiomyocyte-specific genetic knockout of GR blunted or abolished ion channel expression rhythms and abolished the ZT12 susceptibility to pacing-induced VA in isolated hearts. CONCLUSIONS Our study registers a day-night rhythm in chromatin accessibility that accompanies diurnal cycles in ventricular myocytes. Our approaches directly implicate the cardiac GR in the myocyte excitability rhythm and mechanistically link the ZT12 surge in glucocorticoids to intrinsic VA propensity at this time.
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Affiliation(s)
- Roman Tikhomirov
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, United Kingdom (R.T., M.S., A.D.)
| | - Robert H Oakley
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health (R.H.O., J.L., L.R.W., D.R.G., J.A.C.)
| | - Cali Anderson
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
| | - Yirong Xiang
- Department of Physics and Astronomy (Y.X., H.Z.), The University of Manchester, United Kingdom
| | - Sami Al-Othman
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
| | - Matthew Smith
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, United Kingdom (R.T., M.S., A.D.)
| | - Sana Yaar
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
| | - Eleonora Torre
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), F-34094 Montpellier France (E.T., P.M., M.E.M.)
| | - Jianying Li
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health (R.H.O., J.L., L.R.W., D.R.G., J.A.C.)
| | - Leslie R Wilson
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health (R.H.O., J.L., L.R.W., D.R.G., J.A.C.)
| | - David R Goulding
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health (R.H.O., J.L., L.R.W., D.R.G., J.A.C.)
| | - Ian Donaldson
- Bioinformatics Core Facility (I.D.), The University of Manchester, United Kingdom
| | - Erika Harno
- Division of Diabetes, Endocrinology and Gastroenterology (E.H.), The University of Manchester, United Kingdom
| | - Luca Soattin
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
| | - Holly A Shiels
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
| | - Gwilym M Morris
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
- Department of Cardiology, John Hunter Hospital, Newcastle, NSW, Australia (G.M.M.)
| | - Henggui Zhang
- Department of Physics and Astronomy (Y.X., H.Z.), The University of Manchester, United Kingdom
| | - Mark R Boyett
- Faculty of Life Sciences, University of Bradford, United Kingdom (M.R.B.)
| | - John A Cidlowski
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health (R.H.O., J.L., L.R.W., D.R.G., J.A.C.)
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), F-34094 Montpellier France (E.T., P.M., M.E.M.)
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), F-34094 Montpellier France (E.T., P.M., M.E.M.)
| | - Alicia D'Souza
- Division of Cardiovascular Sciences (R.T., C.A., S.A.O., M.S., S.Y., L.S., H.A.S., G.M.M., A.D.), The University of Manchester, United Kingdom
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, United Kingdom (R.T., M.S., A.D.)
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Zheng M, Erhardt S, Cao Y, Wang J. Emerging Signaling Regulation of Sinoatrial Node Dysfunction. Curr Cardiol Rep 2023; 25:621-630. [PMID: 37227579 DOI: 10.1007/s11886-023-01885-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/14/2023] [Indexed: 05/26/2023]
Abstract
PURPOSE OF REVIEW The sinoatrial node (SAN), the natural pacemaker of the heart, is responsible for generating electrical impulses and initiating each heartbeat. Sinoatrial node dysfunction (SND) causes various arrhythmias such as sinus arrest, SAN block, and tachycardia/bradycardia syndrome. Unraveling the underlying mechanisms of SND is of paramount importance in the pursuit of developing effective therapeutic strategies for patients with SND. This review provides a concise summary of the most recent progress in the signaling regulation of SND. RECENT FINDINGS Recent studies indicate that SND can be caused by abnormal intercellular and intracellular signaling, various forms of heart failure (HF), and diabetes. These discoveries provide novel insights into the underlying mechanisms SND, advancing our understanding of its pathogenesis. SND can cause severe cardiac arrhythmias associated with syncope and an increased risk of sudden death. In addition to ion channels, the SAN is susceptible to the influence of various signalings including Hippo, AMP-activated protein kinase (AMPK), mechanical force, and natriuretic peptide receptors. New cellular and molecular mechanisms related to SND are also deciphered in systemic diseases such as HF and diabetes. Progress in these studies contributes to the development of potential therapeutics for SND.
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Affiliation(s)
- Mingjie Zheng
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Shannon Erhardt
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, The University of Texas, Houston, TX, 77030, USA
| | - Yuhan Cao
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jun Wang
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, The University of Texas, Houston, TX, 77030, USA.
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3
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Dorey TW, Mackasey M, Jansen HJ, McRae MD, Bohne LJ, Liu Y, Belke DD, Atkinson L, Rose RA. Natriuretic peptide receptor B maintains heart rate and sinoatrial node function via cyclic GMP-mediated signaling. Cardiovasc Res 2021; 118:1917-1931. [PMID: 34273155 DOI: 10.1093/cvr/cvab245] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 07/16/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Heart rate (HR) is a critical indicator of cardiac performance that is determined by sinoatrial node (SAN) function and regulation. Natriuretic peptides, including C-type NP (CNP) have been shown to modulate ion channel function in the SAN when applied exogenously. CNP is the only NP that acts as a ligand for natriuretic peptide receptor-B (NPR-B). Despite these properties, the ability of CNP and NPR-B to regulate HR and intrinsic SAN automaticity in vivo, and the mechanisms by which it does so, are incompletely understood. Thus, the objective of this study was to determine the role of NPR-B signaling in regulating HR and SAN function. METHODS AND RESULTS We have used NPR-B deficient mice (NPR-B+/-) to study HR regulation and SAN function using telemetry in conscious mice, intracardiac electrophysiology in anesthetized mice, high resolution optical mapping in isolated SAN preparations, patch-clamping in isolated SAN myocytes, and molecular biology in isolated SAN tissue. These studies demonstrate that NPR-B+/- mice exhibit slow HR, increased corrected SAN recovery time, and slowed SAN conduction. Spontaneous AP firing frequency in isolated SAN myocytes was impaired in NPR-B+/- mice due to reductions in the hyperpolarization activated current (If) and L-type Ca2+ current (ICa,L). If and ICa,L were reduced due to lower cGMP levels and increased hydrolysis of cAMP by phosphodiesterase 3 (PDE3) in the SAN. Inhibiting PDE3 or restoring cGMP signaling via application of 8-Br-cGMP abolished the reductions in cAMP, AP firing, If, and ICa,L, and normalized SAN conduction, in the SAN in NPR-B+/- mice. NPR-B+/- mice did not exhibit changes in SAN fibrosis and showed no evidence of cardiac hypertrophy or changes in ventricular function. CONCLUSIONS NPR-B plays an essential physiological role in maintaining normal HR and SAN function by modulating ion channel function in SAN myocytes via a cGMP/PDE3/cAMP signaling mechanism.
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Affiliation(s)
- Tristan W Dorey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Martin Mackasey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Megan D McRae
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Loryn J Bohne
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Logan Atkinson
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Zhao P, Song Z, Wang Y, Cai H, Du X, Li C, Lv J, Liu X, Guo M, Chen Z. The endothelial nitric oxide synthase/cyclic guanosine monophosphate/protein kinase G pathway activates primordial follicles. Aging (Albany NY) 2020; 13:1096-1119. [PMID: 33291075 PMCID: PMC7835019 DOI: 10.18632/aging.202235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 10/20/2020] [Indexed: 01/18/2023]
Abstract
In mammals, the well-organized activation of quiescent primordial follicles is pivotal for female reproductive reserve. In the present study, we examined the mechanisms underlying primordial follicle activation in mice. We found that endothelial nitric oxide synthase (eNOS) and its downstream effectors, cyclic guanosine monophosphate (cGMP) and cGMP-dependent protein kinase G (PKG), were expressed in pre-granulosa cells and promoted primordial follicle activation, oocyte growth and granulosa cell proliferation in neonatal ovaries. Mammalian target of rapamycin (mTOR) colocalized with PKG in pre-granulosa cells and was essential for eNOS/cGMP/PKG pathway-induced primordial follicle activation. The eNOS/cGMP/PKG pathway was found to stabilize mTOR protein. The mRNA levels of F-box and WD repeat domain containing 7 (FBXW7), an E3 ubiquitin ligase, correlated negatively with mTOR protein levels in neonatal ovaries. FBXW7 bound to and destabilized mTOR protein in pre-granulosa cells in a ubiquitin/proteasome-dependent manner. However, agonists of the eNOS/cGMP/PKG pathway reduced FBXW7 mRNA levels. FBXW7 overexpression suppressed primordial follicle activation and prevented the eNOS/cGMP/PKG pathway from activating primordial follicles and stabilizing mTOR protein. These findings demonstrate that the eNOS/cGMP/PKG pathway activates primordial follicles by suppressing FBXW7-induced ubiquitination of mTOR in mice.
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Affiliation(s)
- Peikun Zhao
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Zidai Song
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Yan Wang
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Han Cai
- Fujian Provincial Key Laboratory of Reproductive Health Research, Medical College of Xiamen University, Xiamen, Fujian, China
| | - Xiaoyan Du
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Changlong Li
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Jianyi Lv
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Xin Liu
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Meng Guo
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
| | - Zhenwen Chen
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, School of Basic Medical Sciences, Capital Medical University, Beijing, People’s Republic of China
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cGMP signalling in cardiomyocyte microdomains. Biochem Soc Trans 2020; 47:1327-1339. [PMID: 31652306 DOI: 10.1042/bst20190225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/20/2019] [Accepted: 09/24/2019] [Indexed: 02/07/2023]
Abstract
3',5'-Cyclic guanosine monophosphate (cGMP) is one of the major second messengers critically involved in the regulation of cardiac electrophysiology, hypertrophy, and contractility. Recent molecular and cellular studies have significantly advanced our understanding of the cGMP signalling cascade, its local microdomain-specific regulation and its role in protecting the heart from pathological stress. Here, we summarise recent findings on cardiac cGMP microdomain regulation and discuss their potential clinical significance.
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Demeter-Haludka V, Kovács M, Prorok J, Nagy N, Varró A, Végh Á. Examination of the Changes in Calcium Homeostasis in the Delayed Antiarrhythmic Effect of Sodium Nitrite. Int J Mol Sci 2019; 20:E5687. [PMID: 31766239 PMCID: PMC6888494 DOI: 10.3390/ijms20225687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/09/2019] [Accepted: 11/11/2019] [Indexed: 01/11/2023] Open
Abstract
We have evidence that the intravenous infusion of sodium nitrite (NaNO2) results in an antiarrhythmic effect when given 24 h prior to an ischemia and reperfusion (I/R) insult in anaesthetized dogs. This protection was associated with the reduction of reactive oxygen species resulting from I/R through the attenuation of mitochondrial respiration. Here, we examined whether the changes in calcium, which also contributes to arrhythmia generation, play a role in the NaNO2-induced effect. On the first day, 30 anaesthetized dogs were treated either with saline or NaNO2 (0.2 µmol/kg/min) for 20 min. Some animals were subjected to a 25 min LAD (anterior descending branch of the left coronary artery) occlusion and 2 min reperfusion (I/R = 4; NaNO2-I/R = 6), or the heart was removed 24 h later. We have shown that nitrite prevented the I/R-induced increase in cellular and mitochondrial calcium deposits. During simulated I/R, the amplitude of the calcium transient and the diastolic calcium level were significantly lower in the nitrite-treated hearts and the ERP (effective refractory period) fraction of the action potential was significantly increased. Furthermore, nitrite also enhanced the mitochondrial respiratory response and prevented the MPTPT opening during calcium overload. These results suggest that nitrite can reduce the harmful consequences of calcium overload, perhaps directly by modulating ion channels or indirectly by reducing the mitochondrial ROS (reactive oxygen species) production.
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Affiliation(s)
- Vivien Demeter-Haludka
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
| | - Mária Kovács
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
| | - János Prorok
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
| | - Norbert Nagy
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
- MTA-SZTE Research Group of Cardiovascular Pharmacology, H-6721 Szeged, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
| | - Ágnes Végh
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6721 Szeged, Hungary; (V.D.-H.); (J.P.); (N.N.); (A.V.); (Á.V.)
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Moghtadaei M, Polina I, Rose RA. Electrophysiological effects of natriuretic peptides in the heart are mediated by multiple receptor subtypes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 120:37-49. [DOI: 10.1016/j.pbiomolbio.2015.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/25/2015] [Accepted: 12/02/2015] [Indexed: 12/13/2022]
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Kovács M, Kiss A, Gönczi M, Miskolczi G, Seprényi G, Kaszaki J, Kohr MJ, Murphy E, Végh Á. Effect of sodium nitrite on ischaemia and reperfusion-induced arrhythmias in anaesthetized dogs: is protein S-nitrosylation involved? PLoS One 2015; 10:e0122243. [PMID: 25909651 PMCID: PMC4409072 DOI: 10.1371/journal.pone.0122243] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 02/18/2015] [Indexed: 11/21/2022] Open
Abstract
Background and Purpose To provide evidence for the protective role of inorganic nitrite against acute ischaemia and reperfusion-induced ventricular arrhythmias in a large animal model. Experimental Approach Dogs, anaesthetized with chloralose and urethane, were administered intravenously with sodium nitrite (0.2 µmolkg-1min-1) in two protocols. In protocol 1 nitrite was infused 10 min prior to and during a 25 min occlusion of the left anterior descending (LAD) coronary artery (NaNO2-PO; n = 14), whereas in protocol 2 the infusion was started 10 min prior to reperfusion of the occluded vessel (NaNO2-PR; n = 12). Control dogs (n = 15) were infused with saline and subjected to the same period of ischaemia and reperfusion. Severities of ischaemia and ventricular arrhythmias, as well as changes in plasma nitrate/nitrite (NOx) levels in the coronary sinus blood, were assessed throughout the experiment. Myocardial superoxide and nitrotyrosine (NT) levels were determined during reperfusion. Changes in protein S-nitrosylation (SNO) and S-glutathionylation were also examined. Key Results Compared with controls, sodium nitrite administered either pre-occlusion or pre-reperfusion markedly suppressed the number and severity of ventricular arrhythmias during occlusion and increased survival (0% vs. 50 and 92%) upon reperfusion. There were also significant decreases in superoxide and NT levels in the nitrite treated dogs. Compared with controls, increased SNO was found only in NaNO2-PR dogs, whereas S-glutathionylation occurred primarily in NaNO2-PO dogs. Conclusions Intravenous infusion of nitrite profoundly reduced the severity of ventricular arrhythmias resulting from acute ischaemia and reperfusion in anaesthetized dogs. This effect, among several others, may result from an NO-mediated reduction in oxidative stress, perhaps through protein SNO and/or S-glutathionylation.
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Affiliation(s)
- Mária Kovács
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Attila Kiss
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Márton Gönczi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Gottfried Miskolczi
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - György Seprényi
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - József Kaszaki
- Institute of Surgical Research, Albert Szent-Györgyi Medical Center, University of Szeged, Szeged, Hungary
| | - Mark J Kohr
- Systems Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Elizabeth Murphy
- Systems Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ágnes Végh
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Metabolomics Study of Resina Draconis on Myocardial Ischemia Rats Using Ultraperformance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry Combined with Pattern Recognition Methods and Metabolic Pathway Analysis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:438680. [PMID: 23762136 PMCID: PMC3677627 DOI: 10.1155/2013/438680] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/24/2013] [Accepted: 04/24/2013] [Indexed: 01/08/2023]
Abstract
Resina draconis (bright red resin isolated from Dracaena cochinchinensis, RD) has been clinically used for treatment of myocardial ischemia (MI) for many years. However, the mechanisms of its pharmacological action on MI are still poorly understood. This study aimed to characterize the plasma metabolic profiles of MI and investigate the mechanisms of RD on MI using ultraperformance liquid chromatography/quadrupole time-of-flight mass spectrometry-based metabolomics combined with pattern recognition methods and metabolic pathway analysis. Twenty metabolite markers characterizing metabolic profile of MI were revealed, which were mainly involved in aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine, and tryptophan biosynthesis, vascular smooth muscle contraction, sphingolipid metabolism, and so forth. After RD treatment, however, levels of seven MI metabolite markers, including phytosphingosine, sphinganine, acetylcarnitine, cGMP, cAMP, L-tyrosine, and L-valine, were turned over, indicating that RD is likely to alleviate MI through regulating the disturbed vascular smooth muscle contraction, sphingolipid metabolism, phenylalanine metabolism, and BCAA metabolism. To our best knowledge, this is the first comprehensive study to investigate the mechanisms of RD for treating MI, from a metabolomics point of view. Our findings are very valuable to gain a better understanding of MI metabolic profiles and provide novel insights for exploring the mechanisms of RD on MI.
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Lim SY, Soh JW. Specific Isoforms of Protein Kinase G Downregulate the Transcription of Cyclin D1 in NIH3T3. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.4.1165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
BACKGROUND AND PURPOSE High-fat diet and consequent metabolic syndrome (MS) can lead to elevated risk for cardiac arrhythmias. This preclinical study was to investigate if cicletanine (CIC) could produce cardioprotective effects in conscious rabbits exhibiting the main symptoms of MS. METHODS NZW rabbits that had undergone an 8-week-long cholesterol-enriched diet (1.5%) were instrumented with a pacemaker electrode and randomly assigned into 3 groups according to the oral treatment of either CIC (50 mg·kg) or sotalol (25 mg·kg) and their placebo b.i.d. over 5 days. Study groups were subjected to either "arrhythmia challenge" by programmed electrical stimulation in the "Arrhythmogenesis" study (N = 54) or global myocardial ischemia by rapid pacing in the "Ventricular Overdrive Pacing-induced Myocardial Ischemia" study (N = 18). The antiarrhythmic effect was evaluated by the establishment of the incidence of programmed electrical stimulation-induced arrhythmias. Proarrhythmia indicators (eg, QTc, Tpeak-Tend) were also measured to assess the cardiac safety profile of CIC. To evaluate the background of antiarrhythmic effect, cardiac cyclic nucleotide (cyclic 3',5'-guanosine monophosphate [cGMP], cyclic 3',5'-adenosine monophosphate [cAMP]) and nitric oxide content were determined. The antiischemic effect was characterized by change of intracavital ST segment. RESULTS Cicletanine treatment significantly decreased the incidence of ventricular arrhythmias, increased cardiac cGMP and nitric oxide content and reduced cardiac cAMP level. Cicletanine did not modify significantly QTc and Tpeak-Tend interval. The ST-segment change in response to rapid pacing was reduced significantly by CIC. (P < 0.05). CONCLUSIONS Cicletanine exerts beneficial cardiac effects in rabbits with symptoms of MS, which may be of influence with regard to the clinical application of the drug.
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Abstract
Endothelial cells in the heart, both endocardial endothelium and coronary vascular endothelium, influence myocardial contraction in isolated tissue and pump function in intact hearts by releasing diffusible agents that affect subjacent myocardium. Endocardial endothelium releases both nitric oxide (NO) and an unidentified "contraction-prolonging substance" ("endocardin") that respectively decrease and increase the duration of twitch contraction, probably by altering myofibrillar calcium sensitivity. These agents modulate the duration of ejection and the timing of relaxation, but without significantly altering early systolic behavior. Coronary vascular endothelium also releases NO, with similar effects on contraction, and in addition probably releases several other agents. Current work is aimed at identifying all of the agents involved in these novel endothelial influences and studying their potential physiologic and pathophysiologic roles in cardiac contractile and other functions.
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Expression of cGMP-dependent protein kinase, PKGIα, PKGIβ, and PKGII in malignant and benign breast tumors. Tumour Biol 2012; 33:1927-32. [DOI: 10.1007/s13277-012-0453-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 06/26/2012] [Indexed: 02/02/2023] Open
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Li L, Haider HK, Wang L, Lu G, Ashraf M. Adenoviral short hairpin RNA therapy targeting phosphodiesterase 5a relieves cardiac remodeling and dysfunction following myocardial infarction. Am J Physiol Heart Circ Physiol 2012; 302:H2112-21. [PMID: 22447941 DOI: 10.1152/ajpheart.00339.2011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We previously showed that treatment with tadalafil, a long-acting phosphodiesterase-5a (PDE5a) inhibitor, effectively prevented adverse left ventricular (LV) remodeling of the infarcted heart. We hypothesized that short-hairpin RNA (shRNA) therapy targeting PDE5a would simulate the effects of pharmacological intervention for treatment of postinfarction LV remodeling and dysfunction. Experimental model of myocardial infarction was developed in female mice by permanent ligation of left coronary artery. Immediately after that, an adenoviral vector encoding for shRNA sequence targeting PDE5a (Ad-shPDE5a) was injected intramyocardially, which specifically inhibited PDE5a in the heart. Four weeks later, Ad-shPDE5a treated mice showed significant mitigation of the left ventricle (LV) dilatation and dysfunction as indicated by smaller LV cavity and more preserved ejection fraction and fractional shortening. Infarction size and fibrosis were significantly reduced in Ad-shPDE5a-treated mice. Additionally, more salvaged cardiomyocytes, significantly reduced collagen contents, and higher blood vessel density were observed in Ad-shPDE5a-treated mice. The cytoprotective effects of Ad-shPDE5a were demonstrated in vitro in Ad-shPDE5a transfected cardiomyocytes cultured under oxygen glucose deprivation. Among downstream mediators of PDE5a signaling, cyclic GMP (cGMP) and cGMP-dependent protein kinase G (PKG) were activated with concomitant reduction in caspase-3 activity. However, no significant change in PKA and cAMP activities were observed in Ad-shPDE5a-treated hearts. Inhibition with shRNA improved cardiac remodeling and dysfunction by reducing infarction size and cardiac fibrosis and increased cGMP and PKG activity. These findings suggest that PDE5 inhibition with Ad-shPDE5a is a novel approach for treatment of myocardial infarction.
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Affiliation(s)
- Longhu Li
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45267-0529, USA
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Springer J, Azer J, Hua R, Robbins C, Adamczyk A, McBoyle S, Bissell MB, Rose RA. The natriuretic peptides BNP and CNP increase heart rate and electrical conduction by stimulating ionic currents in the sinoatrial node and atrial myocardium following activation of guanylyl cyclase-linked natriuretic peptide receptors. J Mol Cell Cardiol 2012; 52:1122-34. [PMID: 22326431 DOI: 10.1016/j.yjmcc.2012.01.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Revised: 12/16/2011] [Accepted: 01/24/2012] [Indexed: 11/26/2022]
Abstract
Natriuretic peptides (NPs) are best known for their ability to regulate blood vessel tone and kidney function whereas their electrophysiological effects on the heart are less clear. Here, we measured the effects of BNP and CNP on sinoatrial node (SAN) and atrial electrophysiology in isolated hearts as well as isolated SAN and right atrial myocytes from mice. BNP and CNP dose-dependently increased heart rate and conduction through the heart as indicated by reductions in R-R interval, P wave duration and P-R interval on ECGs. In conjunction with these ECG changes BNP and CNP (100 nM) increased spontaneous action potential frequency in isolated SAN myocytes by increasing L-type Ca(2+) current (I(Ca,L)) and the hyperpolarization-activated current (I(f)). BNP had no effect on right atrial myocyte APs in basal conditions; however, in the presence of isoproterenol (10nM), BNP increased atrial AP duration and I(Ca,L). Quantitative gene expression and immunocytochemistry data show that all three NP receptors (NPR-A, NPR-B and NPR-C) are expressed in the SAN and atrium. The effects of BNP and CNP on SAN and right atrial myocytes were maintained in mutant mice lacking functional NPR-C receptors and blocked by the NPR-A antagonist A71915 indicating that BNP and CNP function through their guanylyl cyclase-linked receptors. Our data also show that the effects of BNP and CNP are completely absent in the presence of the phosphodiesterase 3 inhibitor milrinone. Based on these data we conclude that NPs can increase heart rate and electrical conduction by activating the guanylyl cyclase-linked NPR-A and NPR-B receptors and inhibiting PDE3 activity.
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Affiliation(s)
- Jeremy Springer
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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The regulation of cardiac activity by nitric oxide (NO) in the Vietnamese stick insect, Baculum extradentatum. Cell Signal 2012; 24:1344-50. [PMID: 22306270 DOI: 10.1016/j.cellsig.2012.01.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 01/03/2012] [Accepted: 01/19/2012] [Indexed: 11/20/2022]
Abstract
This study examines the role of the unconventional gaseous signaling molecule nitric oxide (NO) on the regulation of heart rate in the Vietnamese stick insect, Baculum extradentatum. Using nicotinamide dinucleotide hydrogen phosphate (NADPH)-diaphorase histochemistry, as well as immunohistochemistry and Western blotting with an antibody against NO synthetase (NOS), we identified the presence of NOS in hemocytes present throughout the lumen of the dorsal vessel. We propose that NO is delivered to heart muscle tissue via hemocytes circulating within the hemolymph. In the present study, stimulation of NO levels by the application of the NO donor MAHMA-NONOate and l-arginine led to a dose-dependent decrease in heart rate. Treatment of tissues with the NOS inhibitor, L-NAME, in equimolar concentrations with l-arginine, led to a recovery of heart rate, without modifying heart rate on its own. Finally guanosine 3',5'-cyclic monophosphate (cGMP) analog, 8-bromo-cGMP, elicited similar inhibitory effects on stick insect heart rate as did the guanylate cyclase activator, YC-1, and the phosphodiesterase inhibitor, dipyridamole, indicating that cGMP is most likely the second messenger in the stick insect NO signaling pathway. Contrary to the cardioexcitatory effect of NO on other insect hearts, we have found that NO inhibits stick insect heart rate independently from any nervous system input, in a similar inhibitory fashion as that of vertebrate hearts.
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Tsai EJ, Liu Y, Koitabashi N, Bedja D, Danner T, Jasmin JF, Lisanti MP, Friebe A, Takimoto E, Kass DA. Pressure-overload-induced subcellular relocalization/oxidation of soluble guanylyl cyclase in the heart modulates enzyme stimulation. Circ Res 2012; 110:295-303. [PMID: 22095726 PMCID: PMC4264382 DOI: 10.1161/circresaha.111.259242] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 11/08/2011] [Indexed: 01/17/2023]
Abstract
RATIONALE Soluble guanylyl cyclase (sGC) generates cyclic guanosine monophophate (cGMP) upon activation by nitric oxide (NO). Cardiac NO-sGC-cGMP signaling blunts cardiac stress responses, including pressure-overload-induced hypertrophy. The latter itself depresses signaling through this pathway by reducing NO generation and enhancing cGMP hydrolysis. OBJECTIVE We tested the hypothesis that the sGC response to NO also declines with pressure-overload stress and assessed the role of heme-oxidation and altered intracellular compartmentation of sGC as potential mechanisms. METHODS AND RESULTS C57BL/6 mice subjected to transverse aortic constriction (TAC) developed cardiac hypertrophy and dysfunction. NO-stimulated sGC activity was markedly depressed, whereas NO- and heme-independent sGC activation by BAY 60-2770 was preserved. Total sGCα(1) and β(1) expression were unchanged by TAC; however, sGCβ(1) subunits shifted out of caveolin-enriched microdomains. NO-stimulated sGC activity was 2- to 3-fold greater in Cav3-containing lipid raft versus nonlipid raft domains in control and 6-fold greater after TAC. In contrast, BAY 60-2770 responses were >10 fold higher in non-Cav3 domains with and without TAC, declining about 60% after TAC within each compartment. Mice genetically lacking Cav3 had reduced NO- and BAY-stimulated sGC activity in microdomains containing Cav3 for controls but no change within non-Cav3-enriched domains. CONCLUSIONS Pressure overload depresses NO/heme-dependent sGC activation in the heart, consistent with enhanced oxidation. The data reveal a novel additional mechanism for reduced NO-coupled sGC activity related to dynamic shifts in membrane microdomain localization, with Cav3-microdomains protecting sGC from heme-oxidation and facilitating NO responsiveness. Translocation of sGC out of this domain favors sGC oxidation and contributes to depressed NO-stimulated sGC activity.
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Affiliation(s)
- Emily J. Tsai
- Section in Cardiology, Department of Medicine, Temple University School of Medicine, Philadelphia, PA
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Yuchuan Liu
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA
| | - Norimichi Koitabashi
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Djahida Bedja
- Department of Comparative Medicine and Comparative Pathology, Johns Hopkins University Medical Institutions, Baltimore, MD 21205
| | - Thomas Danner
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - Jean-Francois Jasmin
- Department of Stem Cell Biology & Regenerative Medicine, Thomas Jefferson University, Philadelphia, PA
| | - Michael P. Lisanti
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA
| | - Andreas Friebe
- Physiologisches Institut I, Universität Würzburg, Würzburg, Germany
| | - Eiki Takimoto
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
| | - David A. Kass
- Division of Cardiology, Department of Medicine, Johns Hopkins University Medical Institutions, Baltimore, MD
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Fallahian F, Karami-Tehrani F, Salami S. Induction of apoptosis by type Iβ protein kinase G in the human breast cancer cell lines MCF-7 and MDA-MB-468. Cell Biochem Funct 2011; 30:183-90. [PMID: 22095901 DOI: 10.1002/cbf.1831] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 10/06/2011] [Accepted: 10/06/2011] [Indexed: 11/11/2022]
Abstract
Activation of protein kinase G (PKG) by cyclic guanosine 3,5-monophosphate (cGMP) has become of considerable interest as a novel molecular approach for the induction of apoptosis in cancer cells. This study was conducted to investigate the role of PKG isoforms in the regulation of cell growth in human breast cancer cell lines MCF-7 and MDA-MB468. The expression levels of PKG isoforms were also examined using real-time reverse transcriptase polymerase chain reaction. No differences in the gene expression of PKG isoforms were observed between MCF-7 and MDA-MB-468 cells. To investigate the effects of PKG isoforms on the regulation of cell growth, the cGMP analogues 8-APT-cGMP (PKGIα activator), 8-Br-PET-cGMP (PKGIβ activator) and 8-pCPT-cGMP (PKGII activator) were employed. Apoptosis was assessed with the Annexin-V-propidium iodide (PI) staining, cell cycle analysis and caspase-3/9 activity assay. Treatment of MCF-7 and MDA-MB-468 cells with 8-Br-PET-cGMP resulted in a concentration-dependent cell growth inhibition and apoptosis, whereas neither PKGIα nor PKGII activators had any effect on the cell growth. The role of PKGIβ in the inhibition of cell growth was confirmed using PKGI and PKGII inhibitors. The present study is the first to demonstrate the involvement of PKGIβ in the inhibition of cell growth and induction of apoptosis in breast cancer cells.
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Affiliation(s)
- Faranak Fallahian
- Department of Clinical Biochemistry, Cancer Research Laboratory, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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Fallahian F, Karami-Tehrani F, Salami S, Aghaei M. Cyclic GMP induced apoptosis via protein kinase G in oestrogen receptor-positive and -negative breast cancer cell lines. FEBS J 2011; 278:3360-9. [PMID: 21777390 DOI: 10.1111/j.1742-4658.2011.08260.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The activation of protein kinase G (PKG) by cyclic guanosine 3,5-monophosphate (cGMP) has become of considerable interest as a novel molecular approach for the induction of apoptosis in cancer cells. The present study was designed to examine the effects of cGMP and PKG on cell growth and apoptosis in the human breast cancer cell lines, MCF-7 and MDA-MB-468. To achieve this, 1-benzyl-3-(5P-hydroxymethyl-2P-furyl) indazole (YC-1), a soluble guanylyl cyclase activator, and 8-bromo-cGMP (8-br-cGMP), a membrane-permeant and phosphodiesterase-resistant analogue of cGMP, were employed in MCF-7 and MDA-MB-468 cells. Then, the role of PKG in the induction of apoptosis was evaluated using KT5823 and Rp-8-pCPT-cGMP as specific inhibitors of PKG. The expression of PKG isoforms in these cell lines was also investigated. KT5823 and Rp-8-pCPT-cGMP significantly attenuated the loss of cell viability caused by YC-1 and 8-br-cGMP in these cells. This study provides direct evidence that the activation of PKG by cGMP induces growth inhibition and apoptosis in MCF-7 and MDA-MB-468 breast cancer cell lines.
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Affiliation(s)
- Faranak Fallahian
- Department of Clinical Biochemistry, Cancer Research Laboratory, School of Medical Science, Tarbiat Modares University, Tehran, Iran
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Hübner M, Dizayee S, Matthes J, Seifert R, Herzig S. Effect of MANT-nucleotides on L-type calcium currents in murine cardiomyocytes. Naunyn Schmiedebergs Arch Pharmacol 2011; 383:573-83. [PMID: 21484439 DOI: 10.1007/s00210-011-0626-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 03/22/2011] [Indexed: 10/18/2022]
Abstract
Membranous adenylyl cyclases play a major role in G-protein-coupled receptor signalling and regulate various cellular responses, such as cardiac contraction. Cardiac apoptosis and development of cardiac dysfunction is prevented in mice lacking AC 5, a predominant isoform in the heart. In the search for a potent and selective AC 5 inhibitor, we recently identified 2'(3')-methylanthraniloyl-inosine-5'-triphosphate(MANT-ITP) as the most potent AC 5 inhibitor with a K ( i ) of 13 nM. Therefore, AC inhibition of MANT-ITP was assessed in ventricular cardiomyocytes and compared to three other MANT-nucleotides to evaluate its effect on cardiac signalling. Basal and isoproterenol-induced L-type calcium currents (I (Ca,L)) in murine ventricular cardiomyocytes were recorded by whole-cell patch-clamp technique, using four different MANT-nucleotides. The effects of the MANT-nucleotides on I (Ca,L) were unexpectedly complex. All MANT-nucleotides exhibited an inhibitory effect on basal I (Ca,L). Additionally, several MANT-nucleotides, i.e., MANT-ITPγS, MANT-ATP, and MANT-ITP, caused a strong initial increase in basal I (Ca,L) within the first 2.5 min that appeared to be unrelated to AC 5 inhibition. However, we detected a significant reduction on isoproterenol-induced I (Ca,L) with MANT-ITP, supporting the notion that AC 5 plays an important role in agonist-stimulated activation of I (Ca,L). Collectively, MANT-nucleotides are useful tools for the characterization of recombinant ACs, for fluorescence studies and crystallography, but in intact cardiomyocytes, caution must be exerted since MANT-nucleotides apparently possess additional effects than AC 5 inhibition, limiting their usefulness as tools for intact cell studies.
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Affiliation(s)
- Melanie Hübner
- Department of Pharmacology and Toxicology, University of Regensburg, Regensburg, Germany
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21
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Lenaerts I, Holemans P, Pokreisz P, Sipido KR, Janssens S, Heidbuchel H, Willems R. Nitric oxide delays atrial tachycardia-induced electrical remodelling in a sheep model. Europace 2011; 13:747-54. [DOI: 10.1093/europace/eur021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Tamargo J, Caballero R, Gómez R, Delpón E. Cardiac electrophysiological effects of nitric oxide. Cardiovasc Res 2010; 87:593-600. [PMID: 20587506 DOI: 10.1093/cvr/cvq214] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Nitric oxide (NO) synthetized by essentially all cardiac cell types plays a key role in the regulation of cardiac function. Recent evidence shows that NO modulates the activity of cardiac ion channels implicated in the genesis of the cardiac action potential and exerts anti-arrhythmic properties under some circumstances. We review the effects of NO on cardiac ion channels and the signalling pathways, including cGMP-dependent (protein kinase G and cGMP-regulated phosphodiesterases) and cGMP-independent mechanisms (S-nitrosylation and direct effects on G proteins) and finally the role of NO in the genesis of cardiac arrhythmias during ischemia-reperfusion, heart failure, long QT syndrome, atrial fibrillation, and sudden cardiac death.
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Affiliation(s)
- Juan Tamargo
- Department of Pharmacology, School of Medicine, Universidad Complutense, 28040 Madrid, Spain.
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Genetic disruption of G proteins, G(i2)alpha or G(o)alpha, does not abolish inotropic and chronotropic effects of stimulating muscarinic cholinoceptors in atrium. Br J Pharmacol 2010; 158:1557-64. [PMID: 19906118 DOI: 10.1111/j.1476-5381.2009.00441.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Classically, stimulation of muscarinic cholinoceptors exerts negative inotropic and chronotropic effects in the atrium of mammalian hearts. These effects are crucial to the vagal regulation of the heart beat. This effect is assumed to be mediated via GTP binding (G) proteins, because they can be abolished by Pertussis toxin. However, it is unknown which G proteins are involved. EXPERIMENTAL APPROACH We studied contractility in isolated left or right atrium from genetically manipulated mice with deletion of one of two G proteins, either of the alpha subunit of G(i2) protein (G(i2)alpha) or of the alpha subunit of G(o) protein (G(o)alpha). Preparations were stimulated with carbachol alone or after pretreatment with the beta-adrenoceptor agonist isoprenaline. For comparison, the effects of carbachol on L-type Ca(2+)-channels in isolated ventricular cardiomyocytes were studied. KEY RESULTS The negative inotropic and chronotropic effects of carbachol alone or in the presence of isoprenaline were identical in atria from knockout or wild-type mice. However, the effect of carbachol on isoprenaline-activated L-type Ca(2+)-channel in isolated ventricular cardiomyocytes was greatly attenuated in both types of knockout mice studied. CONCLUSIONS AND IMPLICATIONS These data imply that there is either redundancy of G proteins for signal transduction or that Pertussis toxin-sensitive proteins other than G(i2)alpha and G(o)alpha mediate the vagal stimulation in the atrium. Moreover, different G proteins mediate the effect of carbachol in ventricle compared with atrium.
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Casserly B, Klinger JR. Brain natriuretic peptide in pulmonary arterial hypertension: biomarker and potential therapeutic agent. DRUG DESIGN DEVELOPMENT AND THERAPY 2009; 3:269-87. [PMID: 20054445 PMCID: PMC2802126 DOI: 10.2147/dddt.s4805] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
B-type natriuretic peptide (BNP) is a member of the natriuretic peptide family, a group of widely distributed, but evolutionarily conserved, polypeptide mediators that exert myriad cardiovascular effects. BNP is a potent vasodilator with mitogenic, hypertrophic and pro-inflammatory properties that is upregulated in pulmonary hypertensive diseases. Circulating levels of BNP correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with pulmonary arterial hypertension (PAH). Elevated plasma BNP levels are associated with increased mortality in patients with PAH and a fall in BNP levels after therapy is associated with improved survival. These findings have important clinical implications in that a noninvasive blood test may be used to identify PAH patients at high-risk of decompensation and to guide pulmonary vasodilator therapy. BNP also has several biologic effects that could be beneficial to patients with PAH. However, lack of a convenient method for achieving sustained increases in circulating BNP levels has impeded the development of BNP as a therapy for treating pulmonary hypertension. New technologies that allow transdermal or oral administration of the natriuretic peptides have the potential to greatly accelerate research into therapeutic use of BNP for cor pulmonale and pulmonary vascular diseases. This review will examine the basic science and clinical research that has led to our understanding of the role of BNP in cardiovascular physiology, its use as a biomarker of right ventricular function and its therapeutic potential for managing patients with pulmonary vascular disease.
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Affiliation(s)
- Brian Casserly
- Division of Pulmonary and Critical Care Medicine, The Memorial Hospital of Rhode Island, Pawtucket, RI, USA
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Tsai EJ, Kass DA. Cyclic GMP signaling in cardiovascular pathophysiology and therapeutics. Pharmacol Ther 2009; 122:216-38. [PMID: 19306895 PMCID: PMC2709600 DOI: 10.1016/j.pharmthera.2009.02.009] [Citation(s) in RCA: 298] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 02/07/2023]
Abstract
Cyclic guanosine 3',5'-monophosphate (cGMP) mediates a wide spectrum of physiologic processes in multiple cell types within the cardiovascular system. Dysfunctional signaling at any step of the cascade - cGMP synthesis, effector activation, or catabolism - have been implicated in numerous cardiovascular diseases, ranging from hypertension to atherosclerosis to cardiac hypertrophy and heart failure. In this review, we outline each step of the cGMP signaling cascade and discuss its regulation and physiologic effects within the cardiovascular system. In addition, we illustrate how cGMP signaling becomes dysregulated in specific cardiovascular disease states. The ubiquitous role cGMP plays in cardiac physiology and pathophysiology presents great opportunities for pharmacologic modulation of the cGMP signal in the treatment of cardiovascular diseases. We detail the various therapeutic interventional strategies that have been developed or are in development, summarizing relevant preclinical and clinical studies.
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Affiliation(s)
- Emily J Tsai
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA
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Rao YJ, Xi L. Pivotal effects of phosphodiesterase inhibitors on myocyte contractility and viability in normal and ischemic hearts. Acta Pharmacol Sin 2009; 30:1-24. [PMID: 19060915 DOI: 10.1038/aps.2008.1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Phosphodiesterases (PDEs) are enzymes that degrade cellular cAMP and cGMP and are thus essential for regulating the cyclic nucleotides. At least 11 families of PDEs have been identified, each with a distinctive structure, activity, expression, and tissue distribution. The PDE type-3, -4, and -5 (PDE3, PDE4, PDE5) are localized to specific regions of the cardiomyocyte, such as the sarcoplasmic reticulum and Z-disc, where they are likely to influence cAMP/cGMP signaling to the end effectors of contractility. Several PDE inhibitors exhibit remarkable hemodynamic and inotropic properties that may be valuable to clinical practice. In particular, PDE3 inhibitors have potent cardiotonic effects that can be used for short-term inotropic support, especially in situations where adrenergic stimulation is insufficient. Most relevant to this review, PDE inhibitors have also been found to have cytoprotective effects in the heart. For example, PDE3 inhibitors have been shown to be cardioprotective when given before ischemic attack, whereas PDE5 inhibitors, which include three widely used erectile dysfunction drugs (sildenafil, vardenafil and tadalafil), can induce remarkable cardioprotection when administered either prior to ischemia or upon reperfusion. This article provides an overview of the current laboratory and clinical evidence, as well as the cellular mechanisms by which the inhibitors of PDE3, PDE4 and PDE5 exert their beneficial effects on normal and ischemic hearts. It seems that PDE inhibitors hold great promise as clinically applicable agents that can improve cardiac performance and cell survival under critical situations, such as ischemic heart attack, cardiopulmonary bypass surgery, and heart failure.
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Wang L, Henrich M, Buckler KJ, McMenamin M, Mee CJ, Sattelle DB, Paterson DJ. Neuronal nitric oxide synthase gene transfer decreases [Ca2+]i in cardiac sympathetic neurons. J Mol Cell Cardiol 2007; 43:717-25. [PMID: 17961591 DOI: 10.1016/j.yjmcc.2007.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 08/30/2007] [Accepted: 09/06/2007] [Indexed: 01/28/2023]
Abstract
Gene transfer of neuronal nitric oxide synthase (nNOS) can decrease cardiac sympathetic outflow and facilitate parasympathetic neurotransmission. The precise pathway responsible for nitric oxide (NO) mediated inhibition of sympathetic neurotransmission is not known, but may be related to NO-cGMP activation of cGMP-stimulated phosphodiesterase (PDE2) that enhances the breakdown of cAMP to deactivate protein kinase A (PKA), resulting in a decrease in Ca(2+) influx mediated exocytosis of the neurotransmitter. We investigated depolarization evoked Ca(2+) influx in nNOS gene transduced sympathetic neurons from stellate ganglia with a noradrenergic cell specific vector (Ad.PRS-nNOS or empty vector), and examined how nNOS gene transfer affected cAMP and cGMP levels in these neurons. We found that targeting nNOS into these sympathetic neurons reduced amplitudes of voltage activated Ca(2+) transients by 44%. nNOS specific inhibition by N-[(4S)-4-Amino-5-[(2-aminoetyl](amino] pentyl]-N'-nitroguanidine (AAAN) reversed this response. nNOS gene transfer also increased intracellular cGMP (47%) and decreased cAMP (29%). A PDE2 specific inhibitor Bay60-7557 reversed the reduction in cAMP caused by Ad.PRS-nNOS. These results suggest that neuronal NO modulates cGMP and PDE2 to regulate voltage gated intracellular Ca(2+) transients in sympathetic neurons. Therefore, we propose this as a possible key step involved in NO decreasing cardiac sympathetic neurotransmission.
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Affiliation(s)
- Lijun Wang
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, Parks Road, Oxford, UK
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Anyadike C, Scholz PM, Zhang Q, Katz E, Weiss HR. Brain natriuretic peptide reverses the effects of myocardial stunning in rabbit myocardium. Pharmacology 2007; 80:40-8. [PMID: 17519532 DOI: 10.1159/000102984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 02/15/2007] [Indexed: 11/19/2022]
Abstract
We tested the hypothesis that brain natriuretic peptide (BNP) would decrease the effects of myocardial stunning in rabbit hearts. We also examined the mechanisms responsible for these effects. In two groups of anesthetized open-chest rabbits, myocardial stunning was produced by 2 15-min occlusions of the left anterior descending artery separated by 15 min of reperfusion. The treatment group had BNP (10(-3) mol/l) topically applied to the stunned area. Hemodynamic and functional parameters were measured. Coronary flow and O2 extraction were used to determine myocardial O2 consumption. In separate animals, we measured the function of isolated control and simulated ischemia (95% N2/5% CO2, 15 min)-reperfusion ventricular myocytes with BNP or C-type natriuretic peptide (10(-8)-10(-7) mol/l) followed by KT5823 (10(-6) mol/l, cyclic GMP protein kinase inhibitor). In the in vivo control group, baseline delay to contraction was 47+/-4 ms and after stunning it increased to 71+/-10 ms. In the treatment group, baseline delay to contraction was 40+/-7 ms, and after stunning and BNP it did not significantly increase (43+/-6 ms). Neither stunning nor BNP administration affected regional O2 consumption. In control myocytes, BNP (10(-7) mol/l) decreased the percent shortening from 6.7+/-0.4 to 4.5+/-0.2%; after KT5823 administration, the percent shortening increased to 5.4+/-0.5%. In ischemia-reperfusion myocytes, BNP (10(-7) mol/l) decreased the percent shortening less from 5.0+/-0.5 to 3.8+/-0.2%; KT5823 administration did not increase the percent shortening (3.8+/-0.2%). BNP similarly and significantly increased cyclic GMP levels in control and stunned myocytes. The data illustrated that BNP administration reversed the effects of stunning and its mechanism may be independent of the cyclic GMP protein kinase.
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Affiliation(s)
- Chukwuma Anyadike
- Heart and Brain Circulation Laboratory, Department of Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854-5635, USA
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Sosa V, Carbó R, Guarner V. Participation of glucose transporters on atrial natriuretic peptide-induced glucose uptake by adult and neonatal cardiomyocytes under oxygenation and hypoxia. Eur J Pharmacol 2007; 568:83-8. [PMID: 17537429 DOI: 10.1016/j.ejphar.2007.04.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2007] [Revised: 04/18/2007] [Accepted: 04/20/2007] [Indexed: 11/22/2022]
Abstract
Natriuretic peptides, beside their endocrine actions, have paracrine functions which include regulating glucose uptake and metabolism. Atrial natriuretic peptide (ANP) actions are mediated by cGMP which is implicated in the metabolic adaptation of glucose metabolism to oxygen deprivation in the heart. Although, it has been reported that ANP increases glucose uptake, cGMP decreases it. The aim of the present paper was to evaluate the role of the glucose transporters 1 and 4 (GLUTS), in glucose uptake produced by ANP in fatty acid-dependent adult cardiomyocytes and glucose-dependent neonatal cardiomyocytes under oxygenation and hypoxia, which reverts adult metabolism to glucose-dependent. We also explored if the calcium-calmodulin complex participates in ANP-induced increase in glucose uptake. Neonatal cells had a higher glucose uptake than adult cells and GLUT 1 participated in basal uptake in both cell types. Hypoxia increased glucose uptake in adult cardiomyocytes but not in neonatal cells and this increase in glucose uptake was mediated by GLUT4. ANP increased glucose uptake in both adult and neonatal myocytes, under oxygenation and hypoxia, and GLUT4 favored this increase. Neonatal cells were less sensitive to ANP. Trifluoperazine, a calcium-calmodulin blocker, inhibited the ANP-induced increase in glucose uptake. This suggests that ANP promotes GLUT 4 calcium-mediated recruitment to the cell membrane. In conclusion, glucose uptake regulation is one of the paracrine metabolic effects of ANP in adult and neonatal cardiomyocytes under oxygenation and hypoxia. This effect of this peptide could explain the beneficial effects found in the internal medicine and surgical fields.
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Affiliation(s)
- Verónica Sosa
- Physiology Department National Institute of Cardiology Ignacio Chávez, Mexico D.F
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Meyer M, Zhang Q, Khurana K, Scholz PM, Weiss HR. Negative functional effects of natriuretic peptides are attenuated in hypertrophic cardiac myocytes by reduced particulate guanylyl cyclase activity. J Cardiovasc Pharmacol 2007; 49:100-5. [PMID: 17312451 DOI: 10.1097/fjc.0b013e31802e84db] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We tested the hypothesis that the negative functional effects of natriuretic peptides would be blunted in thyroxine (T4)-induced hypertrophic cardiac myocytes. We also studied the causes of these changes. Ventricular myocytes were obtained from control (n=8) and T4 (0.5 mg/kg/16 days) treated rabbit hearts (n=7). Cell shortening parameters were studied with a video edge detector. We also determined particulate (pGC) and soluble (sGC) guanylyl cyclase activity and cyclic GMP levels. Myocyte function was examined at baseline and after brain natriuretic peptide (BNP 10(-7,-6) M) or C-type natriuretic peptide (CNP 10(-7,-6) M) or zaprinast (cyclic GMP phosphodiesterase inhibitor 10(-6)M) followed by BNP or CNP. Baseline function was similar in control and T4 myocytes. BNP (5.7 +/- 0.2 to 4.3 +/- 0.1%) and CNP (5.7 +/- 0.4 to 4.2 +/- 0.2%) significantly reduced percent shortening in control myocytes. These reductions were not observed with T4 (BNP, 5.7 +/- 0.6 to 5.6 +/- 0.6; CNP, 5.6 +/- 0.4 to 5.5 +/- 0.5). BNP and CNP responded similarly after zaprinast. Baseline cyclic GMP was similar in control and T4, but BNP only increased cyclic GMP in controls. The activity of pGC was similar at baseline in control and T4, but the stimulated activity was significantly lower in T4 myocytes. Both basal and stimulated sGC activity were similar in control and hypertrophic myocytes. These results demonstrated that the ability of natriuretic peptides to reduce ventricular myocyte function was blunted in T4 hypertrophic myocytes. This blunted response was related to the reduced ability of natriuretic peptides to increase cyclic GMP levels due to a reduced stimulated particulate guanylyl cyclase activity.
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Affiliation(s)
- Mark Meyer
- Heart and Brain Circulation Laboratory, Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 088854-8021, USA
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Abstract
Growing evidence suggests that multiple spatially, temporally, and functionally distinct pools of cyclic nucleotides exist and regulate cardiac performance, from acute myocardial contractility to chronic gene expression and cardiac structural remodeling. Cyclic nucleotide phosphodiesterases (PDEs), by hydrolyzing cAMP and cyclic GMP, regulate the amplitude, duration, and compartmentation of cyclic nucleotide-mediated signaling. In particular, PDE3 enzymes play a major role in regulating cAMP metabolism in the cardiovascular system. PDE3 inhibitors, by raising cAMP content, have acute inotropic and vasodilatory effects in treating congestive heart failure but have increased mortality in long-term therapy. PDE3A expression is downregulated in human and animal failing hearts. In vitro, inhibition of PDE3A function is associated with myocyte apoptosis through sustained induction of a transcriptional repressor ICER (inducible cAMP early repressor) and thereby inhibition of antiapoptotic molecule Bcl-2 expression. Sustained induction of ICER may also cause the change of other protein expression implicated in human and animal failing hearts. These data suggest that the downregulation of PDE3A observed in failing hearts may play a causative role in the progression of heart failure, in part, by inducing ICER and promoting cardiac myocyte dysfunction. Hence, strategies that maintain PDE3A function may represent an attractive approach to circumvent myocyte apoptosis and cardiac dysfunction.
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Affiliation(s)
- Chen Yan
- Center for Cardiovascular Research, Aab Institute of Biomedical Science, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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Wang HP, Xia Q, Jin HF, Cao CM, Lin GH. Negative inotropic effect of interleukin-2 in the isolated ventricular myocytes: role of NO/sGC pathway. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:3632-5. [PMID: 17271079 DOI: 10.1109/iembs.2004.1404021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The present study is to investigate the effect and possible mechanism of interleukin-2 (IL-2) on the cell contractility in isolated rat cardiomyocytes. Ventricular myocytes were isolated from adult male Sprague-Dawley rats. Contractile responses were evaluated by use of the video tracking system. Contractile properties analyzed in cells electrically stimulated at 0.2Hz included peak velocity of cell shortening (+dL/dtmax), peak velocity of cell relengthening (-dL/dtmax), contraction amplitude (dL) and end-diastolic cell length. Calcium transients of ventricular myocytes were determined by the spectrofluorometric techniques. IL-2 (2.0, 10, 50, 200 and 1000 U/ml) exhibited a dose-dependent inhibition in +dL/dtmax, -dL/dtmax, dL and end-diastolic cell length. Pretreatment with the nitric oxide synthase inhibitor Nomega-nitro-L-arginine methyl ester (L-NAME, 100 microM) and 1H-[1,2,4]oxadiazolo[4,3a]quinoxalin-1-one (ODQ, soluble guanylyl cyclase inhibitor) blocked IL-2-induced inhibition of the contractility. IL-2 at 200 U/ml decreased the amplitude of the [Ca2+]i transient. Pretreatment with the L-NAME or ODQ abolished IL-2-induced inhibition of amplitude of the calcium transient. We conclude that the depressant effect of IL-2 on the contraction and calcium transient of isolated ventricular myocytes is mediated by nitric oxide/soluble guanylyl cyclase pathway.
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Affiliation(s)
- H-P Wang
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, China
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Fischmeister R, Castro LRV, Abi-Gerges A, Rochais F, Jurevicius J, Leroy J, Vandecasteele G. Compartmentation of cyclic nucleotide signaling in the heart: the role of cyclic nucleotide phosphodiesterases. Circ Res 2006; 99:816-28. [PMID: 17038651 DOI: 10.1161/01.res.0000246118.98832.04] [Citation(s) in RCA: 302] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A current challenge in cellular signaling is to decipher the complex intracellular spatiotemporal organization that any given cell type has developed to discriminate among different external stimuli acting via a common signaling pathway. This obviously applies to cAMP and cGMP signaling in the heart, where these cyclic nucleotides determine the regulation of cardiac function by many hormones and neuromediators. Recent studies have identified cyclic nucleotide phosphodiesterases as key actors in limiting the spread of cAMP and cGMP, and in shaping and organizing intracellular signaling microdomains. With this new role, phosphodiesterases have been promoted from the rank of a housekeeping attendant to that of an executive officer.
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Affiliation(s)
- Rodolphe Fischmeister
- INSERM U769, Université Paris-Sud 11, Faculté de Pharmacie, 5, Rue J.-B. Clément, F-92296 Châtenay-Malabry Cedex, France.
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Pitt GS, Dun W, Boyden PA. Remodeled cardiac calcium channels. J Mol Cell Cardiol 2006; 41:373-88. [PMID: 16901502 DOI: 10.1016/j.yjmcc.2006.06.071] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 05/26/2006] [Accepted: 06/22/2006] [Indexed: 10/24/2022]
Abstract
Cardiac calcium channels play a pivotal role in the proper functioning of cardiac cells. In response to various pathologic stimuli, they become remodeled, changing how they function, as they adapt to their new environment. Specific features of remodeled channels depend upon the particular disease state. This review will summarize what is known about remodeled cardiac calcium channels in three disease states: hypertrophy, heart failure and atrial fibrillation. In addition, it will review the recent advances made in our understanding of the function of the various molecular building blocks that contribute to the proper functioning of the cardiac calcium channel.
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Affiliation(s)
- Geoffrey S Pitt
- Department of Medicine, Columbia University, New York, NY, USA
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35
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Stehlik J, Movsesian MA. Inhibitors of cyclic nucleotide phosphodiesterase 3 and 5 as therapeutic agents in heart failure. Expert Opin Investig Drugs 2006; 15:733-42. [PMID: 16787138 DOI: 10.1517/13543784.15.7.733] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cyclic nucleotide phosphodiesterases (PDE) 3 and 5 regulate cAMP and cGMP signalling in cardiac and smooth muscle myocytes. Important advances in the understanding of the roles of these enzymes have recently been made. PDE3 inhibitors have inotropic and vasodilatory properties, and although they acutely improve haemodynamics in patients with heart failure, they do not improve long-term morbidity and mortality. Although combination therapy with beta-adrenergic receptor antagonists or selective inhibition of specific PDE3 isoforms might result in a more favourable long-term outcome, more clinical data are needed to test this proposition. The role of PDE5 inhibitors in the treatment of cardiac disease is evolving. PDE5 inhibitors cause pulmonary and systemic vasodilation. How these drugs will compare with other vasodilators in terms of long-term outcomes in patients with heart failure is unknown. Recent studies also suggest that PDE5 inhibitors may have antihypertropic effects, exerted through increased myocardial cGMP signalling, that could be of additional benefit in patients with heart failure.
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MESH Headings
- 3',5'-Cyclic-AMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-AMP Phosphodiesterases/classification
- 3',5'-Cyclic-AMP Phosphodiesterases/physiology
- 3',5'-Cyclic-GMP Phosphodiesterases/antagonists & inhibitors
- 3',5'-Cyclic-GMP Phosphodiesterases/classification
- 3',5'-Cyclic-GMP Phosphodiesterases/physiology
- Adrenergic beta-Antagonists/administration & dosage
- Adrenergic beta-Antagonists/therapeutic use
- Animals
- Cardiomyopathy, Hypertrophic/drug therapy
- Cardiomyopathy, Hypertrophic/enzymology
- Cardiomyopathy, Hypertrophic/prevention & control
- Cardiotonic Agents/pharmacology
- Cardiotonic Agents/therapeutic use
- Coronary Circulation/drug effects
- Cyclic AMP/metabolism
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Cyclic GMP/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 3
- Cyclic Nucleotide Phosphodiesterases, Type 5
- Drug Evaluation, Preclinical
- Drug Therapy, Combination
- Drugs, Investigational/pharmacology
- Drugs, Investigational/therapeutic use
- Enzyme Activation/drug effects
- Forecasting
- Half-Life
- Heart Failure/complications
- Heart Failure/drug therapy
- Heart Failure/enzymology
- Humans
- Hypertension, Pulmonary/drug therapy
- Hypertension, Pulmonary/enzymology
- Hypertension, Pulmonary/etiology
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/physiology
- Multicenter Studies as Topic
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Phosphodiesterase Inhibitors/pharmacology
- Phosphodiesterase Inhibitors/therapeutic use
- Phosphorylation/drug effects
- Prospective Studies
- Protein Processing, Post-Translational/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- Pulmonary Circulation/drug effects
- Randomized Controlled Trials as Topic
- Rats
- Treatment Outcome
- Vasodilator Agents/pharmacology
- Vasodilator Agents/therapeutic use
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Affiliation(s)
- Josef Stehlik
- University of Utah School of Medicine, Cardiology Section, VA Salt Lake City Healthcare System, 500 Foothill Boulevard, Salt Lake City, UT 84117, USA.
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Seya K, Furukawa KI, Yoshida K, Narita R, Motomura S. Nifedipine enhances cGMP production through the activation of soluble guanylyl cyclase in rat ventricular papillary muscle. J Pharm Pharmacol 2006; 57:511-4. [PMID: 15831213 DOI: 10.1211/0022357055740] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
It is known that nifedipine, an L-type calcium channel blocker, increases cGMP production, which partially contributes to the relaxation of vascular smooth muscle. The aim of our investigation was to clarify whether or not nifedipine regulates cGMP production, which has a physiological role in cardiac muscle. To measure contractile responses and tissue cGMP levels, left ventricular papillary muscles prepared from male Wistar rats (350-400 g) were mounted in the isolated organ chamber under isometric conditions and electrically paced by means of platinum punctate electrodes (1 Hz, 1 ms duration). In papillary muscle preparation, the negative inotropic effect induced by nifedipine (30 to 300 nM) was significantly inhibited in the presence of ODQ(1H-[1,2,4]oxidazolo[4,3-a]quinoxaline1-one; 10 microM), a soluble guanylyl cyclase inhibitor. Furthermore, nifedipine (100 nM) strongly increased the tissue cGMP level, which was significantly decreased in the presence of ODQ. On the other hand,N(G)-monomethyl-(L)-arginine (100 microM), a nitric oxide synthase inhibitor, did not inhibit either the negative inotropic effect or cGMP production induced by nifedipine. These results indicate that in rat left ventricular papillary muscle, nifedipine augments its negative inotropic effect at least partly through direct activation of cardiac soluble guanylyl cyclase but not nitric oxide synthase.
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Affiliation(s)
- Kazuhiko Seya
- Department of Pharmacology, Hirosaki University School of Medicine, Zaifu-cho 5, Hirosaki 036-8562, Japan.
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37
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Maass DL, White J, Horton JW. Nitric oxide donors alter cardiomyocyte cytokine secretion and cardiac function. Crit Care Med 2006; 33:2794-803. [PMID: 16352962 DOI: 10.1097/01.ccm.0000189747.97541.59] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTS The mechanisms by which nitric oxide produces beneficial/detrimental effects on physiologic function are unclear. In this study, we hypothesized that nitric oxide promotes cyclic guanosine monophosphate (cGMP) formation, which, in turn, promotes cardiomyocyte secretion of inflammatory cytokines as well as accumulation of intracellular Na+/Ca2+; these factors contribute to altered cardiac contractile function. DESIGN Laboratory study. SETTING Medical Center. SUBJECTS Adult Sprague Dawley rats weighing 325-350 g. INTERVENTIONS Cardiomyocytes were prepared by collagenase perfusion of rat hearts; cells were plated (5 x 10(4) cells/microtiter well) and challenged with either vehicle or nitric oxide donor (S-nitroso-N-acetyl-penicillamine [SNAP] or PAPA NONOATE, 3-[2-Hydroxy-2-nitroso-1-propythdrazinol]-1-propanamine], NOC-15 [PAPA-NO], 0.3 or 1.0 mM of each nitric oxide donor) in the presence/absence of methylene blue (10 microM/L to inhibit cGMP). After 3 hrs, supernatants were collected to measure nitrite/nitrate (nitric oxide), cytokines (tumor necrosis factor-alpha, interleukin-1beta, interleukin-6), and cGMP levels; cells were then loaded with a fluorescent indicator (Fura-2AM or sodium-binding benzofurzan isophthalate) to measure myocyte Ca2+ or Na+, respectively. Parallel experiments included the addition of nitric oxide donor (0.3 or 1.0 mM SNAP or PAPA-NO) to perfused hearts in presence or absence of the methylene blue to examine cGMP-mediated effects on myocardial contraction-relaxation, while other experiments determined a) potential lipopolysaccharide contamination of myocyte preparations; and b) whether a cGMP analogue recapitulated the effects of nitric oxide donors on cytokine secretion. MEASUREMENTS AND MAIN RESULTS Nitric oxide donors produced a dose-dependent increase in cGMP levels in myocyte supernatants as well as an increase in myocyte cytokine secretion, increased myocyte loading of Na+/Ca2+, and produced myocardial contractile dysfunction. Addition of the cGMP analog, 8-bromo-cGMP, recapitulated the effects of nitric oxide donors on myocyte cytokine secretion. Nitric oxide donor-related effects were ablated by pretreatment of myocytes or isolated hearts with methylene blue. Treatment of myocytes with recombinant bactericidal/permeability-increasing protein to scavenge lipopolysaccharide confirmed that cytokine responses to nitric oxide donors were not related to lipopolysaccharide contamination of myocyte preparations. CONCLUSIONS We suggest that nitric oxide synthesis in injury and disease promotes cGMP formation, which, in turn, modulates cardiac contraction/relaxation by a) altering cardiomyocyte secretion of inflammatory cytokines and b) altering myocyte handling of Na+/Ca2+.
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Affiliation(s)
- David L Maass
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
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38
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Hambleton R, Krall J, Tikishvili E, Honeggar M, Ahmad F, Manganiello VC, Movsesian MA. Isoforms of cyclic nucleotide phosphodiesterase PDE3 and their contribution to cAMP hydrolytic activity in subcellular fractions of human myocardium. J Biol Chem 2005; 280:39168-74. [PMID: 16172121 DOI: 10.1074/jbc.m506760200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Three isoforms of PDE3 (cGMP-inhibited) cyclic nucleotide phosphodiesterase regulate cAMP content in different intracellular compartments of cardiac myocytes in response to different signals. We characterized the catalytic activity and inhibitor sensitivity of these isoforms by using recombinant proteins. We determined their contribution to cAMP hydrolysis in cytosolic and microsomal fractions of human myocardium at 0.1 and 1.0 microm cAMP in the absence and presence of Ca(2+)/calmodulin. We examined the effects of cGMP on cAMP hydrolysis in these fractions. PDE3A-136, PDE3A-118, and PDE3A-94 have similar K(m) and k(cat) values for cAMP and are equal in their sensitivities to inhibition by cGMP and cilostazol. In microsomes, PDE3A-136, PDE3A-118, and PDE3A-94 comprise the majority of cAMP hydrolytic activity under all conditions. In cytosolic fractions, PDE3A-118 and PDE3A-94 comprise >50% of the cAMP hydrolytic activity at 0.1 microm cAMP, in the absence of Ca(2+)/calmodulin. At 1.0 microm cAMP, in the presence of Ca(2+)/calmodulin, activation of Ca(2+)/calmodulin-activated (PDE1) and other non-PDE3 phosphodiesterases reduces their contribution to <20% of cAMP hydrolytic activity. cGMP inhibits cAMP hydrolysis in microsomal fractions by inhibiting PDE3 and in cytosolic fractions by inhibiting both PDE3 and PDE1. These findings indicate that the contribution of PDE3 isoforms to the regulation of cAMP hydrolysis in intracellular compartments of human myocardium and the effects of PDE3 inhibition on cAMP hydrolysis in these compartments are highly dependent on intracellular [Ca(2+)] and [cAMP], which are lower in failing hearts than in normal hearts. cGMP may amplify cAMP-mediated signaling in intracellular compartments of human myocardium by PDE3-dependent and PDE3-independent mechanisms.
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Affiliation(s)
- Ryan Hambleton
- Cardiology Section, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah 84148, USA
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39
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Su J, Scholz PM, Tse J, Weiss HR. Effects of cyclic GMP and its protein kinase on the contraction of ventricular myocytes from hearts after cardiopulmonary arrest. Can J Physiol Pharmacol 2005; 82:986-92. [PMID: 15644938 DOI: 10.1139/y04-105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hearts undergoing cardiopulmonary arrest and resuscitation have depressed function and may have changes in signal transduction. We hypothesized that the cyclic GMP (cGMP) signaling pathway would be altered in the post-resuscitation heart. This was studied in ventricular myocytes from 7 anesthetized open-chest rabbits. Cardiopulmonary arrest was achieved for 10 min through ventricular fibrillation and respirator shutdown. After cardiopulmonary arrest, respiration was resumed, the heart was defibrillated, and the heart recovered for 15 min. Seven additional rabbits served as controls. Myocyte function was measured via a video edge detector. Myocytes were treated with 8-bromo-cGMP (10(-5)-10(-6) mol/L) followed by KT5823 (10(-6) mol/L, cGMP protein kinase inhibitor). The baseline percent shortening was significantly depressed in the cardiac arrest myocytes compared with control (3.3 +/- 0.1 vs. 5.5 +/- 0.3%). Treatment with 8-Br-cGMP similarly and dose-dependently reduced cell contraction in both cardiac arrest (-24%) and control (-25%) myocytes. The negative effect of 8-Br-cGMP was partially reversed by KT5823 in control myocytes, but not in the arrest group, indicating reduced involvement of cGMP protein kinase. Multiple proteins were specifically phosphorylated when cGMP was present, but the degree of phosphorylation was significantly less in myocytes after cardiac arrest. The data suggested that the basal contraction was reduced, but the functional response to 8-Br-cGMP was preserved in myocytes from cardiopulmonary arrested hearts. The results also indicated that the action of cGMP appeared to be mainly through non-cGMP protein kinase pathways in the post-resuscitation heart.
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Affiliation(s)
- Jun Su
- Department of Physiology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854-5635, USA
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40
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Fischmeister R, Castro L, Abi-Gerges A, Rochais F, Vandecasteele G. Species- and tissue-dependent effects of NO and cyclic GMP on cardiac ion channels. Comp Biochem Physiol A Mol Integr Physiol 2005; 142:136-43. [PMID: 15927494 DOI: 10.1016/j.cbpb.2005.04.012] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2005] [Revised: 04/17/2005] [Accepted: 04/19/2005] [Indexed: 01/08/2023]
Abstract
Biochemical studies have established the presence of a NO pathway in the heart, including sources of NO and various effectors. Several cardiac ion channels have been shown to be modified by NO, such as L-type Ca(2+), ATP-sensitive K(+), and pacemaker f-channels. Some of these effects are mediated by cGMP, through the activity of three main proteins: the cGMP-dependent protein kinase (PKG), the cGMP-stimulated phosphodiesterase (PDE2) and the cGMP-inhibited PDE (PDE3). Other effects appear independent of cGMP, as for instance the NO modulation of the ryanodine receptor-Ca(2+) channel. In the case of the cardiac L-type Ca(2+) channel current (I(Ca,L)), both cGMP-dependent and cGMP-independent effects have been reported, with important tissue and species specificity. For instance, in rabbit sinoatrial myocytes, NO inhibits the beta-adrenergic stimulation of I(Ca,L) through activation of PDE2. In cat and human atrial myocytes, NO potentiates the cAMP-dependent stimulation of I(Ca,L) through inhibition of PDE3. In rabbit atrial myocytes, NO enhances I(Ca,L) in a cAMP-independent manner through the activation of PKG. In ventricular myocytes, NO exerts opposite effects on I(Ca,L): an inhibition mediated by PKG in mammalian myocytes but by PDE2 in frog myocytes; a stimulation attributed to PDE3 inhibition in frog ventricular myocytes but to a direct effect of NO in ferret ventricular myocytes. Finally, NO can also regulate cardiac ion channels by a direct action on G-proteins and adenylyl cyclase.
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Affiliation(s)
- Rodolphe Fischmeister
- INSERM U-446, Laboratoire de Cardiologie Cellulaire et Moléculaire, Faculté de Pharmacie, Université Paris-Sud, 5, Rue J.-B. Clément, F-92296 Châtenay-Malabry Cedex, France.
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Zhang Q, Lazar M, Yan L, He Y, Tse J, Weiss HR, Scholz PM. Cyclic GMP reduces myocardial stunning through non-cyclic GMP protein kinase mechanisms. J Cardiovasc Pharmacol 2005; 44:235-43. [PMID: 15243306 DOI: 10.1097/00005344-200408000-00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We tested the hypothesis that myocardial stunning would be reduced by increased cyclic GMP and cGMP protein kinase activity. Hearts were instrumented in eight open-chest anesthetized dogs. The left anterior descending coronary artery (LAD) was occluded for 15 minutes followed by a 30-minute recovery and infusion of 8-Bromo-cGMP (0.1 and 1 microg/kg/min) during functional and metabolic data collection. Myocytes from circumflex and LAD regions were then used to obtain data at baseline, with 8-Br-cGMP (10(-7, -6, -5) M) and KT5823 10(-6) M, cGMP protein kinase inhibitor. The in vivo time delay of regional shortening increased significantly from 55 +/- 12 to 99 +/- 3 msec following stunning, but was reduced to 81 +/- 2 by 1 microg/kg/min 8-Br-cGMP. The % regional work during systole decreased during stunning (93 +/- 2 to 76 +/- 8%), but was restored by 8-Br-cGMP (91 +/- 7). Stunning lengthened the time of myocyte contraction and relaxation and reduced baseline shortening. 8-Br-cGMP reduced myocyte shortening in both regions. However, KT5823 only restored myocyte shortening in controls. These data indicated that regional myocardial stunning could be reduced by cyclic GMP but this appeared to be through non-cGMP protein kinase mechanisms.
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Affiliation(s)
- Qihang Zhang
- Department of Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, 08903, USA
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Yan L, Zhang Q, Scholz PM, Weiss HR. Cyclic GMP protein kinase activity is reduced in thyroxine-induced hypertrophic cardiac myocytes. Clin Exp Pharmacol Physiol 2004; 30:943-50. [PMID: 14678234 DOI: 10.1111/j.1440-1681.2003.03936.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. We tested the hypothesis that the cGMP-dependent protein kinase has major negative functional effects in cardiac myocytes and that the importance of this pathway is reduced in thyroxine (T4; 0.5 mg/kg per day for 16 days) hypertrophic myocytes. 2. Using isolated ventricular myocytes from control (n = 7) and T4-treated (n = 9) rabbit hypertrophic hearts, myocyte shortening was studied with a video edge detector. Oxygen consumption was measured using O2 electrodes. Protein phosphorylation was measured autoradiographically. 3. Data were collected following treatment with: (i) 8-(4-chlorophenylthio)guanosine-3',5'-monophosphate (PCPT; 10-7 or 10-5 mol/L); (ii) 8-bromo-cAMP (10-5 mol/L) followed by PCPT; (iii) beta-phenyl-1,N2-etheno-8-bromoguanosine-3',5'-monophosphorothioate, SP-isomer (SP; 10-7 or 10-5 mol/L); or (iv) 8-bromo-cAMP (10-5 mol/L) followed by SP. 4. There were no significant differences between groups in baseline percentage shortening (Pcs; 4.9 +/- 0.2 vs 5.6 +/- 0.4% for control and T4 groups, respectively) and maximal rate of shortening (Rs; 64.8 +/- 5.9 vs 79.9 +/- 7.1 micro m/ s for control and T4 groups, respectively). Both SP and PCPT decreased Pcs (-43 vs-21% for control and T4 groups, respectively) and Rs (-36 vs-22% for control and T4 groups, respectively), but the effect was significantly reduced in T4 myocytes. 8-Bromo-cAMP similarly increased Pcs (28 vs 23% for control and T4 groups, respectively) and Rs (20 vs 19% for control and T4 groups, respectively). After 8-bromo-cAMP, SP and PCPT decreased Pcs (-34%) and Rs (-29%) less in the control group. However, the effects of these drugs were not altered in T4 myocytes (Pcs -24%; Rs -22%). Both PCPT and cAMP phosphorylated the same five protein bands. In T4 myocytes, these five bands were enhanced less. 5. We conclude that, in control ventricular myocytes, the cGMP-dependent protein kinase exerted major negative functional effects but, in T4-induced hypertrophic myocytes, the importance of this pathway was reduced and the interaction between cAMP and the cGMP protein kinase was diminished.
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Affiliation(s)
- Lin Yan
- Heart and Brain Circulation Laboratory, Departments of Physiology & Biophysics and Surgery, University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey 08854-5635, USA
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Zivadinovic D, Gametchu B, Watson CS. Membrane estrogen receptor-alpha levels in MCF-7 breast cancer cells predict cAMP and proliferation responses. Breast Cancer Res 2004; 7:R101-12. [PMID: 15642158 PMCID: PMC1064104 DOI: 10.1186/bcr958] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 08/18/2004] [Accepted: 10/07/2004] [Indexed: 05/01/2023] Open
Abstract
Introduction 17β-estradiol (E2) can rapidly induce cAMP production, but the conditions under which these cAMP levels are best measured and the signaling pathways responsible for the consequent proliferative effects on breast cancer cells are not fully understood. To help resolve these issues, we compared cAMP mechanistic responses in MCF-7 cell lines selected for low (mERlow) and high (mERhigh) expression of the membrane form of estrogen receptor (mER)-α, and thus addressed the receptor subform involved in cAMP signaling. Methods MCF-7 cells were immunopanned and subsequently separated by fluorescence activated cell sorting into mERhigh (mER-α-enriched) and mERlow (mER-α-depleted) populations. Unique (compared with previously reported) incubation conditions at 4°C were found to be optimal for demonstrating E2-induced cAMP production. Time-dependent and dose-dependent effects of E2 on cAMP production were determined for both cell subpopulations. The effects of forskolin, 8-CPT cAMP, protein kinase A inhibitor (H-89), and adenylyl cyclase inhibitor (SQ 22,536) on E2-induced cell proliferation were assessed using the crystal violet assay. Results We demonstrated a rapid and transient cAMP increase after 1 pmol/l E2 stimulation in mERhigh cells; at 4°C these responses were much more reliable and robust than at 37°C (the condition most often used). The loss of cAMP at 37°C was not due to export. 3-Isobutyl-1-methylxanthine (IBMX; 1 mmol/l) only partially preserved cAMP, suggesting that multiple phosphodiesterases modulate its level. The accumulated cAMP was consistently much higher in mERhigh cells than in mERlow cells, implicating mER-α levels in the process. ICI172,780 blocked the E2-induced response and 17α-estradiol did not elicit the response, also suggesting activity through an estrogen receptor. E2 dose-dependent cAMP production, although biphasic in both cell types, was responsive to 50-fold higher E2 concentrations in mERhigh cells. Proliferation of mERlow cells was stimulated over the whole range of E2concentrations, whereas the number of mERhigh cells was greatly decreased at concentrations above 1 nmol/l, suggesting that estrogen over-stimulation can lead to cell death, as has previously been reported, and that mER-α participates. E2-mediated activation of adenylyl cyclase and downstream participation of protein kinase A were shown to be involved in these responses. Conclusion Rapid mER-α-mediated nongenomic signaling cascades generate cAMP and downstream signaling events, which contribute to the regulation of breast cancer cell number.
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Affiliation(s)
- Dragoslava Zivadinovic
- Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bahiru Gametchu
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Cheryl S Watson
- Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas, USA
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Deguchi A, Thompson WJ, Weinstein IB. Activation of protein kinase G is sufficient to induce apoptosis and inhibit cell migration in colon cancer cells. Cancer Res 2004; 64:3966-73. [PMID: 15173009 DOI: 10.1158/0008-5472.can-03-3740] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The activation of protein kinase G (PKG) by cGMP has become of considerable interest as a novel molecular mechanism for the induction of apoptosis in cancer cells, because sulindac sulfone (exisulind, Aptosyn) and certain derivatives that inhibit cGMP-phosphodiesterases and thereby increase cellular levels of cGMP appear to induce apoptosis via this mechanism. However, other effects of these compounds have not been excluded, and the precise mechanism by which PKG activation induces apoptosis has not been elucidated in detail. To directly examine the effects of PKG on cell growth and apoptosis, we generated a series of mutants of PKG Ialpha: PKG IalphaS65D, a constitutively activated point mutant; PKG IalphaDelta, a constitutively activated N-terminal truncated mutant; and PKG IalphaK390R, a dominant-negative point mutant. A similar series of mutants of PKG Ibeta were also constructed (Deguchi et al., Mol. Cancer Ther., 1: 803-809, 2002). The present study demonstrates that when transiently expressed in SW480 colon cancer, the constitutively activated mutants of PKG Ibeta, and to a lesser extent PKG Ialpha, inhibit colony formation and induce apoptosis. We were not able to obtain derivatives of SW480 cells that stably expressed these constitutively activated mutants, presumably because of toxicity. However, derivatives that stably overexpressed wild-type PKG Ibeta displayed growth inhibition, whereas derivatives that stably expressed the dominant-negative mutant (KR) of PKG Ibeta grew more rapidly and were more resistant to Aptosyn-induced growth inhibition than vector control cells. Stable overexpression of PKG Ibeta was associated with decreased cellular levels of beta-catenin and cyclin D1 and increased levels of p21(CIP1). Reporter assays indicated that activation of PKG Ibeta inhibits the transcriptional activity of the cyclin D1 promoter. We also found that transient expression of the constitutively activated mutants of PKG Ibeta inhibited cell migration. Taken together, these results indicate that activation of PKG Ibeta is sufficient to inhibit growth and cell migration and induce apoptosis in human colon cancer cells and that these effects are associated with inhibition of the transcription of cyclin D1 and an increase in the expression of p21(CIP1).
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Affiliation(s)
- Atsuko Deguchi
- Herbert Irving Comprehensive Cancer Center, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032-2704, USA
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Abstract
The natriuretic peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), are a family of polypeptide mediators exerting numerous actions in cardiovascular homeostasis. ANP and BNP are cardiac derived, being secreted and up-regulated in myocardium in response to many pathophysiological stimuli. CNP is an endothelium-derived mediator. The classical endocrine effects of ANP and BNP on fluid homeostasis and blood pressure, especially in conditions characterised by left ventricular dysfunction, are well recognised and extensively researched. However, there is accumulating evidence that, in addition to endocrine actions, ANP and BNP exhibit important autocrine and paracrine functions within the heart and coronary circulation. These include regulation of myocyte growth, inhibition of fibroblast proliferation and extracellular matrix deposition, a cytoprotective anti-ischaemic (preconditioning-like) function, and influences on coronary endothelium and vascular smooth muscle proliferation and contractility. Most if not all of these actions can be ascribed to particulate guanylyl cyclase activation because the ANP/BNP receptor, natriuretic peptide receptor (NPR)-A, has an intracellular guanylyl cyclase domain. Subsequent elevation of the intracellular second messenger cGMP may exert diverse physiological effects through activation of cGMP-dependent protein kinases (cGK), predominantly cGK-I. However, there appear to be other contributory mechanisms in several of these actions, including the augmentation of nitric oxide synthesis. These diverse actions may represent counterregulatory mechanisms in the pathophysiology of many cardiovascular diseases, not just those typified by left ventricular dysfunction. Ultimately, insights from the autocrine/paracrine actions of natriuretic peptides may provide routes to therapeutic application in cardiac diseases of natriuretic peptides and drugs that modify their availability.
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Rodriguez R, Molino B, Weiss HR, Scholz PM. Negative metabolic and coronary flow effects of decreases in cAMP and increases in cGMP in control and renal hypertensive rabbit hearts. J Appl Physiol (1985) 2004; 97:439-45. [PMID: 14990553 DOI: 10.1152/japplphysiol.01115.2003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The interaction during stimulation of cGMP and inhibition of cAMP was investigated in control and renal hypertensive hearts. Control and hypertensive [1 kidney, 1 clip (1K1C)] rabbits were used. The anesthetized open-chest groups were vehicle, 8-bromo-cGMP (8-Br-cGMP; 10(-3)M), propranolol (Prop; 2 mg/kg), and Prop + 8-Br-cGMP. O(2) consumption levels (Vo(2)) in the subepicardium (Epi) and subendocardium (Endo) were determined from coronary flow (microspheres) and O(2) extraction (microspectrophotometry). Wall thickening and cAMP levels were also determined. In control, no significant change in Vo(2) was seen for the 8-Br-cGMP group, but Vo(2) was decreased from Epi (9.7 +/- 1.5 ml O(2) x min(-1) x 100 g(-1)) and Endo (10.5 +/- 0.4 ml O(2) x min(-1) x 100 g(-1)) to 6.8 +/- 0.6/7.8 +/- 0.5 ml O(2) x min(-1) x 100 g(-1) in the control Prop group. Control Prop + 8-Br-cGMP did not cause a further fall in Vo(2) but lowered Endo flow. In 1K1C, Vo(2) decreased from Epi/Endo (10.8 +/- 1.3/11 +/- 1.0 ml O(2).min(-1).100 g(-1)) to 7.8 +/- 1.1/8.7 +/- 0.5 ml O(2) x min(-1) x 100 g(-1) in the 1K1C 8-Br-cGMP group and to 7 +/- 0.5/8.1 +/- 0.5 ml O(2) x min(-1) x 100 g(-1) in the 1K1C Prop group. 1K1C Prop + 8-Br-cGMP did not cause a further fall in Vo(2) but lowered blood flow. No significant changes in cAMP levels were present with 8-Br-cGMP in control or 1K1C rabbits, but significant decreases were seen with Prop in both control and 1K1C rabbits. No further change was seen in Prop + 8-Br-cGMP for either control or 1K1C. Thus the negative metabolic effect of stimulating cGMP was seen only in the hypertensive rabbit heart. The negative metabolic effect of inhibiting cAMP was seen in both the control and the hypertensive rabbit heart. However, the negative metabolic effects of cGMP and cAMP were nonadditive.
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Affiliation(s)
- Roberto Rodriguez
- Department of Surgery, Robert Wood Johnson Medical School, Brunswick, NJ 08903-0019, USA
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Wollert KC, Yurukova S, Kilic A, Begrow F, Fiedler B, Gambaryan S, Walter U, Lohmann SM, Kuhn M. Increased effects of C-type natriuretic peptide on contractility and calcium regulation in murine hearts overexpressing cyclic GMP-dependent protein kinase I. Br J Pharmacol 2003; 140:1227-36. [PMID: 14609817 PMCID: PMC1574150 DOI: 10.1038/sj.bjp.0705567] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. C-type natriuretic peptide (CNP) and its receptor guanylyl cyclase (GC-B) are expressed in the heart and modulate cardiac contractility in a cGMP-dependent manner. Since the distal cellular signalling pathways remain unclear, we evaluated the peptide effects on cardiac function and calcium regulation in wild-type (WT) and transgenic mice with cardiac overexpression of cGMP-dependent protein kinase I (PKG ITG). 2. In isolated, perfused working WT hearts, CNP (10 nm) provoked an immediate increase in the maximal rates of contraction and relaxation, a small increase in the left ventricular systolic pressure and a decrease in the time of relaxation. These changes in cardiac function were accompanied by a marked increase in the levels of Ser16-phosphorylated phospholamban (PLB). 3. In PKG ITG hearts, the effects of CNP on cardiac contractility and relaxation as well as on PLB phosphorylation were markedly enhanced. 4. CNP increased cell shortening and systolic Cai2+ levels, and accelerated Cai2+ decay in isolated, Indo-1/AM-loaded WT cardiomyocytes, and these effects were enhanced in PKG I-overexpressing cardiomyocytes. 5. 8-pCPT-cGMP, a membrane-permeable PKG activator, mimicked the contractile and molecular actions of CNP, the effects again being more pronounced in PKG ITG hearts. In contrast, the cardiac responses to beta-adrenergic stimulation were not different between genotypes. 6. Taken together, our data indicate that PKG I is a downstream target activated by the CNP/GC-B/cGMP-signalling pathway in cardiac myocytes. cGMP/PKG I-stimulated phosphorylation of PLB and subsequent activation of the sarcoplasmic reticulum Ca2+ pump appear to mediate the positive inotropic and lusitropic responses to CNP.
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Affiliation(s)
- Kai C Wollert
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Sevdalina Yurukova
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Ana Kilic
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Frank Begrow
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
| | - Beate Fiedler
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | - Stepan Gambaryan
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Ulrich Walter
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Suzanne M Lohmann
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Michaela Kuhn
- Institute of Pharmacology and Toxicology, Universitäts Klinikum Münster, Domagkstrasse 12, Münster D-48129, Germany
- Author for correspondence:
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Abstract
The parasympathetic component of the autonomic nervous system plays an important role in the physiological regulation of cardiac function by exerting significant influence over the initiation as well as propagation of electrical impulses, in addition to being able to regulate contractile force. These effects are mediated in whole or in part through changes in ion channel activity that occur in response to activation of M(2) muscarinic cholinergic receptors following release of the neurotransmitter acetylcholine. The coupling of M(2) receptor activation to most changes in cardiac ion channel function can be explained by one of two general paradigms. The first involves direct G protein-dependent regulation of ion channel activity. The second involves indirect regulation of ion channel activity through modulation of cAMP-dependent responses. This review focuses on recent advances in our understanding of the mechanisms by which M(2) muscarinic receptor activation both inhibits and facilitates cAMP-dependent ion channel responses in the heart.
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Affiliation(s)
- Robert D Harvey
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4970, U.S.A.
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D'Souza SP, Yellon DM, Martin C, Schulz R, Heusch G, Onody A, Ferdinandy P, Baxter GF. B-type natriuretic peptide limits infarct size in rat isolated hearts via KATP channel opening. Am J Physiol Heart Circ Physiol 2003; 284:H1592-600. [PMID: 12521930 DOI: 10.1152/ajpheart.00902.2002] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
B-type natriuretic peptide (BNP) has been reported to be released from the myocardium during ischemia. We hypothesized that BNP mediates cardioprotection during ischemia-reperfusion and examined whether exogenous BNP limits myocardial infarction and the potential role of ATP-sensitive potassium (K(ATP)) channel opening. Langendorff-perfused rat hearts underwent 35 min of left coronary artery occlusion and 120 min of reperfusion. The control infarct-to-risk ratio was 44.8 +/- 4.4% (means +/- SE). BNP perfused 10 min before ischemia limited infarct size in a concentration-dependent manner, with maximal protection observed at 10(-8) M (infarct-to-risk ratio: 20.1 +/- 5.2%, P < 0.01 vs. control), associated with a 2.5-fold elevation of myocardial cGMP above the control value. To examine the role of K(ATP) channel opening, glibenclamide (10(-6) M), 5-hydroxydecanoate (5-HD; 10(-4) M), or HMR-1098 (10(-5) M) was coperfused with BNP (10(-8) M). Protection afforded by BNP was abolished by glibenclamide or 5-HD but not by HMR-1098, suggesting the involvement of putative mitochondrial but not sarcolemmal K(ATP) channel opening. We conclude that natriuretic peptide/cGMP/K(ATP) channel signaling may constitute an important injury-limiting mechanism in myocardium.
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Affiliation(s)
- Savio P D'Souza
- The Hatter Institute, University College London Hospitals and Medical School, London WC1E 6BT, United Kingdom
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Huang MW, Scholz PM, Weiss HR. Increases in myocardial cyclic GMP attenuate contractile delay in myocardial stunning. Can J Physiol Pharmacol 2003; 80:804-10. [PMID: 12269791 DOI: 10.1139/y02-103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that the effects of myocardial stunning would be reduced by cyclic GMP in rabbit hearts. In three groups of anesthetized open-chest New Zealand white rabbits, myocardial stunning was produced by 15 min of occlusion of the left anterior descending coronary artery followed by 15 min of reperfusion repeated twice. Either control vehicle (saline plus 1% dimethyl sulfoxide) or 8-bromo-cyclic GMP (8-Br-cGMP (10(-4) and 10(-3) M)) was topically applied to the left ventricular surface. Hemodynamic (left ventricular and aortic pressures) and functional parameters (wall thickening, delay in onset of wall thickening, and rate of wall thickening) were determined. Coronary blood flow (microspheres) and O2 extraction (microspectrophotometry) were used to determine myocardial O2 consumption (VO2). Myocardial stunning was observed in the control group through an increased delay in onset of myocardial wall thickening (29 +/- 7 versus 55 +/- 16 ms) and decreased maximal rate of wall thickening (20 +/- 8 versus 11 +/- 3 mm x s(-1)). After treatment with 8-Br-cGMP 10(-4) and 10(-3) M, stunning did not increase the delay (37 +/- 5 versus 39 +/- 7 and 39 +/- 7 versus 28 +/- 8 ms). Myocardial stunning did not significantly alter VO2. 8-Br-cGMP 10(-3) M significantly decreased subepicardial VO2 (6.2 +/- 0.8 versus 3.7 +/- 0.6 mL O2 x min(-1) 100 g(-1)) and insignificantly decreased subendocardial VO2 (8.6 +/- 0.9 versus 6.3 +/- 1.2 mL O2 x min(-1) x 100 g(-1)) when compared with the vehicle-treated rabbits. We conclude that increasing cyclic GMP reduced the effects of myocardial stunning in the rabbit heart by ameliorating the delay in onset of wall thickening and decreasing the local O2 costs in the stunned region.
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Affiliation(s)
- Mark W Huang
- Department of Surgery, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854-5635, USA
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