1
|
Noordali H, Loudon BL, Frenneaux MP, Madhani M. Cardiac metabolism - A promising therapeutic target for heart failure. Pharmacol Ther 2017; 182:95-114. [PMID: 28821397 DOI: 10.1016/j.pharmthera.2017.08.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Both heart failure with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF) are associated with high morbidity and mortality. Although many established pharmacological interventions exist for HFrEF, hospitalization and death rates remain high, and for those with HFpEF (approximately half of all heart failure patients), there are no effective therapies. Recently, the role of impaired cardiac energetic status in heart failure has gained increasing recognition with the identification of reduced capacity for both fatty acid and carbohydrate oxidation, impaired function of the electron transport chain, reduced capacity to transfer ATP to the cytosol, and inefficient utilization of the energy produced. These nodes in the genesis of cardiac energetic impairment provide potential therapeutic targets, and there is promising data from recent experimental and early-phase clinical studies evaluating modulators such as carnitine palmitoyltransferase 1 inhibitors, partial fatty acid oxidation inhibitors and mitochondrial-targeted antioxidants. Metabolic modulation may provide significant symptomatic and prognostic benefit for patients suffering from heart failure above and beyond guideline-directed therapy, but further clinical trials are needed.
Collapse
Affiliation(s)
- Hannah Noordali
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Brodie L Loudon
- Norwich Medical School, University of East Anglia, Norwich, UK
| | | | - Melanie Madhani
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
| |
Collapse
|
2
|
Rincon MY, VandenDriessche T, Chuah MK. Gene therapy for cardiovascular disease: advances in vector development, targeting, and delivery for clinical translation. Cardiovasc Res 2015; 108:4-20. [PMID: 26239654 PMCID: PMC4571836 DOI: 10.1093/cvr/cvv205] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 07/22/2015] [Indexed: 01/06/2023] Open
Abstract
Gene therapy is a promising modality for the treatment of inherited and acquired cardiovascular diseases. The identification of the molecular pathways involved in the pathophysiology of heart failure and other associated cardiac diseases led to encouraging preclinical gene therapy studies in small and large animal models. However, the initial clinical results yielded only modest or no improvement in clinical endpoints. The presence of neutralizing antibodies and cellular immune responses directed against the viral vector and/or the gene-modified cells, the insufficient gene expression levels, and the limited gene transduction efficiencies accounted for the overall limited clinical improvements. Nevertheless, further improvements of the gene delivery technology and a better understanding of the underlying biology fostered renewed interest in gene therapy for heart failure. In particular, improved vectors based on emerging cardiotropic serotypes of the adeno-associated viral vector (AAV) are particularly well suited to coax expression of therapeutic genes in the heart. This led to new clinical trials based on the delivery of the sarcoplasmic reticulum Ca2+-ATPase protein (SERCA2a). Though the first clinical results were encouraging, a recent Phase IIb trial did not confirm the beneficial clinical outcomes that were initially reported. New approaches based on S100A1 and adenylate cyclase 6 are also being considered for clinical applications. Emerging paradigms based on the use of miRNA regulation or CRISPR/Cas9-based genome engineering open new therapeutic perspectives for treating cardiovascular diseases by gene therapy. Nevertheless, the continuous improvement of cardiac gene delivery is needed to allow the use of safer and more effective vector doses, ultimately bringing gene therapy for heart failure one step closer to reality.
Collapse
Affiliation(s)
- Melvin Y Rincon
- Department of Gene Therapy and Regenerative Medicine, Free University of Brussels (VUB), Building D, room D306, Laarbeeklaan 103, Brussels, Belgium Centro de Investigaciones, Fundacion Cardiovascular de Colombia, Floridablanca, Colombia
| | - Thierry VandenDriessche
- Department of Gene Therapy and Regenerative Medicine, Free University of Brussels (VUB), Building D, room D306, Laarbeeklaan 103, Brussels, Belgium Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Marinee K Chuah
- Department of Gene Therapy and Regenerative Medicine, Free University of Brussels (VUB), Building D, room D306, Laarbeeklaan 103, Brussels, Belgium Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| |
Collapse
|
3
|
Leontyev S, Schlegel F, Spath C, Schmiedel R, Nichtitz M, Boldt A, Rübsamen R, Salameh A, Kostelka M, Mohr FW, Dhein S. Transplantation of engineered heart tissue as a biological cardiac assist device for treatment of dilated cardiomyopathy. Eur J Heart Fail 2013; 15:23-35. [PMID: 23243122 DOI: 10.1093/eurjhf/hfs200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIM The aim of this study was to characterize an alternative treatment for dilated cardiomyopathy (DCM) using a novel cardiac biological assist device created from engineered heart tissue (EHT). METHODS AND RESULTS The EHTs were constructed in vitro from matrigel, collagen, and neonatal rat cardiomyocytes as small ring-like spontaneously contracting devices. DCM was induced in 50 rats by 6 weeks doxorubicin treatment (2.5 mg/kg/week). After 38 drug-free days, rats underwent either implantation of EHT (DCM-EHT, n = 13), which was sutured around the ventricles, or sham operation (DCM-Sham, n = 12). Eleven untreated healthy rats served as the control group. Rats were investigated using a Millar catheter for pressure-volume loop recording, and by echocardiography 30 days after operation. Thereafter, the hearts were excised and investigated functionally, histologically, and biochemically. Doxorubicin led to the development of DCM with reduced fractional shortening (FS), reduced dP/dt(max), increased systolic and diastolic LV diameters, and reduced response to dobutamine. In DCM-Sham, these changes were further enhanced, while in DCM-EHT we found improved FS, dP/dt(max), and dobutamine responsiveness. In isolated hearts, electrical multielectrode mapping revealed that EHT was electrically activated synchronously to the recipient heart. Histologically, we found increased vascularization in the EHT and the recipient heart, and EHT vessels connected to the coronary system. CONCLUSIONS Implantation of EHT improves LV performance in rats with doxorubicin-induced DCM.
Collapse
Affiliation(s)
- Sergey Leontyev
- Clinic for Cardiac Surgery, Heart Centre Leipzig, Leipzig, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Dhein S, Garbade J, Rouabah D, Abraham G, Ungemach FR, Schneider K, Ullmann C, Aupperle H, Gummert JF, Mohr FW. Effects of autologous bone marrow stem cell transplantation on beta-adrenoceptor density and electrical activation pattern in a rabbit model of non-ischemic heart failure. J Cardiothorac Surg 2006; 1:17. [PMID: 16800896 PMCID: PMC1533828 DOI: 10.1186/1749-8090-1-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Accepted: 06/26/2006] [Indexed: 01/01/2023] Open
Abstract
Background Since only little is known on stem cell therapy in non-ischemic heart failure we wanted to know whether a long-term improvement of cardiac function in non-ischemic heart failure can be achieved by stem cell transplantation. Methods White male New Zealand rabbits were treated with doxorubicine (3 mg/kg/week; 6 weeks) to induce dilative non-ischemic cardiomyopathy. Thereafter, we obtained autologous bone marrow stem cells (BMSC) and injected 1.5–2.0 Mio cells in 1 ml medium by infiltrating the myocardium via a left anterolateral thoracotomy in comparison to sham-operated rabbits. 4 weeks later intracardiac contractility was determined in-vivo using a Millar catheter. Thereafter, the heart was excised and processed for radioligand binding assays to detect β1- and β2-adrenoceptor density. In addition, catecholamine plasma levels were determined via HPLC. In a subgroup we investigated cardiac electrophysiology by use of 256 channel mapping. Results In doxorubicine-treated animals β-adrenoceptor density was significantly down-regulated in left ventricle and septum, but not in right ventricle, thereby indicating a typical left ventricular heart failure. Sham-operated rabbits exhibited the same down-regulation. In contrast, BMSC transplantation led to significantly less β-adrenoceptor down-regulation in septum and left ventricle. Cardiac contractility was significantly decreased in heart failure and sham-operated rabbits, but was significantly higher in BMSC-transplanted hearts. Norepinephrine and epinephrine plasma levels were enhanced in heart failure and sham-operated animals, while these were not different from normal in BMSC-transplanted animals. Electrophysiological mapping revealed unaltered electrophysiology and did not show signs of arrhythmogeneity. Conclusion BMSC transplantation improves sympathoadrenal dysregualtion in non-ischemic heart failure.
Collapse
Affiliation(s)
- Stefan Dhein
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | - Jens Garbade
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | - Djazia Rouabah
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | - Getu Abraham
- Institute for Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, Germany
| | - Fritz-Rupert Ungemach
- Institute for Pharmacology, Pharmacy and Toxicology, Faculty of Veterinary Medicine, University of Leipzig, Germany
| | - Katja Schneider
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | - Cris Ullmann
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | - Heike Aupperle
- Institute of Veterinary Pathology, University of Leipzig, Faculty of Veterinary Medicine, Germany
| | - Jan Fritz Gummert
- Clinic for Cardiac Surgery, Heart Centre Leipzig, University of Leipzig, Germany
| | | |
Collapse
|
5
|
Winstel R, Ihlenfeldt HG, Jung G, Krasel C, Lohse MJ. Peptide inhibitors of G protein-coupled receptor kinases. Biochem Pharmacol 2005; 70:1001-8. [PMID: 16102734 DOI: 10.1016/j.bcp.2005.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 06/13/2005] [Accepted: 06/16/2005] [Indexed: 11/22/2022]
Abstract
G protein-coupled receptor kinases (GRKs) are regulatory enzymes involved in the modulation of seven-transmembrane-helix receptors. In order to develop specific inhibitors for these kinases, we synthesized and investigated peptide inhibitors derived from the sequence of the first intracellular loop of the beta2-adrenergic receptor. Introduction of changes in the sequence and truncation of N- and C-terminal amino acids increased the inhibitory potency by a factor of 40. These inhibitors not only inhibited the prototypical GRK2 but also GRK3 and GRK5. In contrast there was no inhibition of protein kinase C and protein kinase A even at the highest concentration tested. The peptide with the sequence AKFERLQTVTNYFITSE inhibited GRK2 with an IC50 of 0.6 microM, GRK3 with 2.6 microM and GRK5 with 1.6 microM. The peptide inhibitors were non-competitive for receptor and ATP. These findings demonstrate that specific peptides can inhibit GRKs in the submicromolar range and suggest that a further decrease in size is possible without losing the inhibitory potency.
Collapse
Affiliation(s)
- Rainer Winstel
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Str. 9, 97078 Würzburg, Germany
| | | | | | | | | |
Collapse
|
6
|
|
7
|
Foerster K, Kaeferstein T, Groner F, Engelhardt S, Matthes J, Koch WJ, Lohse MJ, Herzig S. Calcium channel function and regulation in beta 1- and beta 2-adrenoceptor transgenic mice. Naunyn Schmiedebergs Arch Pharmacol 2004; 369:490-5. [PMID: 15083268 DOI: 10.1007/s00210-004-0928-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2003] [Accepted: 03/22/2004] [Indexed: 12/13/2022]
Abstract
Cardiac effects of catecholamines on the L-type calcium channel depend on beta-adrenoceptor subtype (beta(1)- vs. beta(2)-adrenoceptor). Chronic overexpression of these receptors leads to hypertrophy and early death at moderate (beta(1)) or excessive (beta(2)) levels of overexpression respectively. In order to examine the role of L-type calcium channels in altered cardiomyocyte calcium homeostasis found with beta(1)-adrenoceptor overexpression, and to understand the quantitative differences between beta-adrenoceptor subtypes regarding calcium channel regulation, we examined single channels in myocytes obtained from beta(1)- and beta(2)-adrenoceptor transgenic mice. The effects of the agonist isoproterenol were investigated and compared with acute receptor stimulation in the respective non-transgenic littermates. Channels from beta(1)-adrenoceptor transgenic mice have normal baseline activity, and channel number is not reduced. This contrasts to previous findings with beta(2)-adrenoceptor transgenic mice, where channel activity is depressed. Isoproterenol is unable to stimulate channel activity in both transgenic models. In conclusion, the L-type calcium channel is not likely to be involved in alterations of calcium handling of beta(1)-adrenoceptor transgenic myocytes. Furthermore, chronic beta(1)-adrenoceptor overexpression does not depress channel activity, giving another example of the difference between beta(1)- and beta(2)-adrenoceptor signal transduction.
Collapse
MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Calcium Channel Blockers/metabolism
- Calcium Channels/drug effects
- Calcium Channels/physiology
- Isoproterenol/pharmacology
- Isradipine/metabolism
- Mice
- Mice, Transgenic
- Myocytes, Cardiac
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/physiology
Collapse
Affiliation(s)
- Katharina Foerster
- Department of Pharmacology, University of Cologne, Gleueler Strasse 24, 50931 Cologne, Germany
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
This review addresses open questions about the role of beta-adrenergic receptors in cardiac function and failure. Cardiomyocytes express all three beta-adrenergic receptor subtypes-beta1, beta2, and, at least in some species, beta3. The beta1 subtype is the most prominent one and is mainly responsible for positive chronotropic and inotropic effects of catecholamines. The beta2 subtype also increases cardiac function, but its ability to activate nonclassical signaling pathways suggests a function distinct from the beta1 subtype. In heart failure, the sympathetic system is activated, cardiac beta-receptor number and function are decreased, and downstream mechanisms are altered. However, in spite of a wealth of data, we still do not know whether and to what extent these alterations are adaptive/protective or detrimental, or both. Clinically, beta-adrenergic antagonists represent the most important advance in heart failure therapy, but it is still debated whether they act by blocking or by resensitizing the beta-adrenergic receptor system. Newer experimental therapeutic strategies aim at the receptor desensitization machinery and at downstream signaling steps.
Collapse
Affiliation(s)
- Martin J Lohse
- Institute of Pharmacology, Versbacher Strasse 9, 97078 Wuerzburg, Germany.
| | | | | |
Collapse
|
9
|
Eckhart AD, Fentzke RC, Lepore J, Lang R, Lin H, Lefkowitz RJ, Koch WJ, Leiden JM. Inhibition of betaARK1 restores impaired biochemical beta-adrenergic receptor responsiveness but does not rescue CREB(A133) induced cardiomyopathy. J Mol Cell Cardiol 2002; 34:669-77. [PMID: 12054854 DOI: 10.1006/jmcc.2002.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The myocardial beta-adrenergic receptor (betaAR) system plays a key role in dysfunctional signaling and physiology of the failing heart. Recently we described a murine model of dilated cardiomyopathy (DCM) produced by cardiac-specific expression of a dominant negative form of the CREB transcription factor (CREB(A133) mice). CREB(A133) mice display abnormalities within the betaAR signaling system including loss of inotropic reserve. Rapid desensitization of betaARs is mediated by the betaAR kinase (betaARK1), which is upregulated during heart failure. Inhibition of betaARK1 activity in the heart via expression of a peptide inhibitor (betaARKct) has been shown to enhance myocardial function and to "rescue" several animal models of heart failure. To determine the role of betaAR dysfunction in the progression of DCM in the CREB(A133) mice, we interbred them with mice expressing the betaARKct. Concurrent expression of the betaARKct peptide and CREB(A133) in mouse hearts resulted in the normalization of elevated betaARK1 levels. This biochemical change resulted in partial restoration of isoproterenol-stimulated adenylate cyclase activity as well as improvement in fractional shortening in response to betaAR stimulation. Interestingly, the progression of DCM and premature mortality was not altered. Therefore, the pathogenesis of DCM in CREB(A133) mice does not appear to involve abnormal betaAR signaling as a key element in its pathological progression and accordingly, the restoration of betaAR signaling is not sufficient to prevent the development and progression of all forms of heart failure.
Collapse
Affiliation(s)
- Andrea D Eckhart
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Shui Z, Khan IA, Haga T, Benovic JL, Boyett MR. Control of the cardiac muscarinic K+ channel by beta-arrestin 2. J Biol Chem 2001; 276:11691-7. [PMID: 11152693 DOI: 10.1074/jbc.m011007200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Control of the cardiac muscarinic K(+) current (i(K,ACh)) by beta-arrestin 2 has been studied. In Chinese hamster ovary cells transfected with m2 muscarinic receptor, muscarinic K(+) channel, receptor kinase (GRK2), and beta-arrestin 2, desensitization of i(K,ACh) during a 3-min application of 10 micrometer ACh was significantly increased as compared with that in cells transfected with receptor, channel, and GRK2 only (fade in current increased from 45 to 78%). The effect of beta-arrestin 2 was lost if cells were not co-transfected with GRK2. Resensitization (recovery from desensitization) of i(K,ACh) in cells transfected with beta-arrestin 2 was significantly slowed (time constant increased from 34 to 232 s). Activation and deactivation of i(K,ACh) on application and wash-off of ACh in cells transfected with beta-arrestin 2 were significantly slowed from 0.9 to 3.1 s (time to half peak i(K,ACh)) and from 6.2 to 13.8 s (time to half-deactivation), respectively. In cells transfected with a constitutively active beta-arrestin 2 mutant, desensitization occurred in the absence of agonist (peak current significantly decreased from 0.4 +/- 0.05 to 0.1 +/- 0.01 nA). We conclude that beta-arrestin 2 has the potential to play a major role in desensitization and other aspects of the functioning of the muscarinic K(+) channel.
Collapse
Affiliation(s)
- Z Shui
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | | | | | | | | |
Collapse
|
11
|
Chen EP, Bittner HB, Akhter SA, Koch WJ, Davis RD. Myocardial function in hearts with transgenic overexpression of the G protein-coupled receptor kinase 5. Ann Thorac Surg 2001; 71:1320-4. [PMID: 11308180 DOI: 10.1016/s0003-4975(00)01754-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Chronic heart failure is associated with impairment of the myocardial beta-adrenergic receptor (beta-AR) system. In this study, the effects of G protein-coupled receptor kinase 5 (GRK5) overexpression on myocardial performance were directly assessed in the hearts of transgenic mice using an isolated work-performing murine heart preparation and computerized analysis of functional data. METHODS A controlled experimental study was performed to evaluate cardiac function in both transgenic mice with a 30-fold overexpression of GRK5 (n = 9, 23 to 29 g) and littermate controls (n = 10, 22 to 29 g). Preload-dependent cardiac output, contractility, stroke work, stroke volume, and heart rate were compared between the two groups. RESULTS Significant decreases in preload-dependent cardiac output and contractility were observed in the mice with GRK5 overexpression when compared with control group mice and occurred in association with significant decreases in stroke work and stroke volume. There was no significant difference in the average heart rate between the two groups. CONCLUSIONS These data suggest that GRK5 upregulation may be partially responsible for alterations in myocardial function in chronic heart failure.
Collapse
Affiliation(s)
- E P Chen
- Division of Cardiothoracic Surgery, Duke University Medical Center, Durham, North Carolina, USA.
| | | | | | | | | |
Collapse
|
12
|
Anderson KM, Eckhart AD, Willette RN, Koch WJ. The myocardial beta-adrenergic system in spontaneously hypertensive heart failure (SHHF) rats. Hypertension 1999; 33:402-7. [PMID: 9931137 DOI: 10.1161/01.hyp.33.1.402] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
-Responsiveness to beta-adrenergic stimulation is reduced in the failing human myocardium. This results principally from reduced beta-adrenergic receptor (betaAR) density, elevated beta-adrenergic receptor kinase 1 (betaARK1) levels, and functional uncoupling of remaining receptors. The temporal nature of changes in the human myocardial beta-adrenergic system relative to onset of symptomatic heart failure (HF) has been difficult to discern. A relatively new model of HF, the spontaneously hypertensive heart failure (SHHF) rat spontaneously and reproducibly develops left ventricular hypertrophy (LVH) and progresses to HF, thus enabling longitudinal studies to examine the cellular and molecular bases for hypertension-induced cardiac hypertrophy and subsequent HF. The purpose of this study was to examine age-dependent changes in the betaAR system in this model. Lean male SHHF rats at 3, 7, 14, and 20 months were compared with age-matched Sprague-Dawley (SD) control rats ([C]; 4 animals/group). At all ages the SHHF rats had elevated blood pressures and left ventricular end-diastolic pressure relative to the SD control rats (P<0.05). Compared with age-matched SD control rats, LVH was evident by 3 months in SHHF rats; 20-month-old SHHF rats had significantly greater LVH compared with the other SHHF rat groups. beta-adrenergic responsiveness (maximal heart rate to isoproterenol) was reduced only in 20-month-old SHHF rats. betaARK1 protein levels and activity were elevated at 14 months (162+/-10% and 195+/-20% C, respectively), and betaARK1 protein remained elevated at 20 months (140+/-14% C). In contrast, G protein-coupled receptor kinase 5, a second receptor kinase in the heart, remained unchanged at all ages. betaAR density did not change with age in the SD control rats and was similar in the SHHF rats until 20 months of age when the receptor number was reduced (30+/-1%). These data indicate that cardiac dysfunction is coincident with reduced betaAR density. Importantly, cardiac dysfunction was preceded by elevated betaARK1 levels and activity, thus suggesting that betaARK1 may be a precipitating factor in the transition from hypertension-induced compensatory cardiac hypertrophy to HF. Furthermore, these results indicate that the SHHF rat is a powerful model for use in examination of the mechanisms involved in alterations of beta-adrenergic signaling that occur in human HF.
Collapse
Affiliation(s)
- K M Anderson
- Department of Cardiovascular Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406, USA.
| | | | | | | |
Collapse
|
13
|
Abstract
Protein phosphorylation acts a pivotal mechanism in regulating the contractile state of the heart by modulating particular levels of autonomic control on cardiac force/length relationships. Early studies of changes in cardiac protein phosphorylation focused on key components of the excitation-coupling process, namely phospholamban of the sarcoplasmic reticulum and myofibrillar troponin I. In more recent years the emphasis has shifted towards the identification of other phosphoproteins, and more importantly, the delineation of the mechanistic and signaling pathways regulating the various known phosphoproteins. In addition to cAMP- and Ca(2+)-calmodulin-dependent kinase processes, these have included regulation by protein kinase C and the ever-emerging family of growth factor-related kinases such as the tyrosine-, mitogen- and stress-activated protein kinases. Similarly, the role of protein dephosphorylation by protein phosphatases has been recognized as integral in modulating normal cardiac cellular function. Recent studies involving a variety of cardiovascular pathologies have demonstrated that changes in the phosphorylation states of key cardiac regulatory proteins may underlie cardiac dysfunction in disease states. The emphasis of this comprehensive review will be on discussing the role of cardiac phosphoproteins in regulating myocardial function and pathophysiology based not only on in vitro data, but more importantly, from ex vivo experiments with corroborative physiological and biochemical evidence.
Collapse
Affiliation(s)
- S T Rapundalo
- Department of Biochemistry, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert, Ann Arbor, MI 48105, USA.
| |
Collapse
|
14
|
Shui Z, Khan IA, Tsuga H, Haga T, Boyett MR. Role of receptor kinase in short-term desensitization of cardiac muscarinic K+ channels expressed in Chinese hamster ovary cells. J Physiol 1998; 507 ( Pt 2):325-34. [PMID: 9518696 PMCID: PMC2230799 DOI: 10.1111/j.1469-7793.1998.325bt.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
1. The cardiac muscarinic receptor-K+ channel system was reconstructed in Chinese hamster ovary (CHO) cells by transfecting the cells with the various components of the system. The activity of the muscarinic K+ channel was measured with the cell-attached configuration of the patch clamp technique. 2. In CHO cells transfected with the channel (Kir3.1/Kir3.4), receptor (hm2) and receptor kinase (GRK2), on exposure to agonist, there was a decline in channel activity as a result of desensitization, similar to that in atrial cells. 3. Whereas the desensitization was almost abolished by not transfecting with the receptor kinase or by transfecting with a mutant receptor lacking phosphorylation sites, it was only reduced (by approximately 39%) by transfecting with a mutant receptor kinase with little/kinase activity. 4. These results suggest that the receptor kinase is responsible for desensitization of the muscarinic K+ channel and that this involves phosphorylation-dependent and -independent mechanisms.
Collapse
Affiliation(s)
- Z Shui
- Department of Physiology, University of Leeds, UK
| | | | | | | | | |
Collapse
|
15
|
Ménard L, Ferguson SSG, Zhang J, Lin FT, Lefkowitz RJ, Caron MG, Barak LS. Synergistic Regulation of β2-Adrenergic Receptor Sequestration: Intracellular Complement of β-Adrenergic Receptor Kinase and β-Arrestin Determine Kinetics of Internalization. Mol Pharmacol 1997. [DOI: 10.1124/mol.51.5.800] [Citation(s) in RCA: 186] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
16
|
Jaber M, Koch WJ, Rockman H, Smith B, Bond RA, Sulik KK, Ross J, Lefkowitz RJ, Caron MG, Giros B. Essential role of beta-adrenergic receptor kinase 1 in cardiac development and function. Proc Natl Acad Sci U S A 1996; 93:12974-9. [PMID: 8917529 PMCID: PMC24031 DOI: 10.1073/pnas.93.23.12974] [Citation(s) in RCA: 278] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The beta-adrenergic receptor kinase 1 (beta ARK1) is a member of the G protein-coupled receptor kinase (GRK) family that mediates the agonist-dependent phosphorylation and desensitization of G protein-coupled receptors. We have cloned and disrupted the beta ARK1 gene in mice by homologous recombination. No homozygote beta ARK1-/- embryos survive beyond gestational day 15.5. Prior to gestational day 15.5, beta ARK1-/- embryos display pronounced hypoplasia of the ventricular myocardium essentially identical to the "thin myocardium syndrome" observed upon gene inactivation of several transcription factors (RXR alpha, N-myc, TEF-1, WT-1). Lethality in beta ARK1-/- embryos is likely due to heart failure as they exhibit a > 70% decrease in cardiac ejection fraction determined by direct in utero intravital microscopy. These results along with the virtual absence of endogenous GRK activity in beta ARK1-/- embryos demonstrate that beta ARK1 appears to be the predominant GRK in early embryogenesis and that it plays a fundamental role in cardiac development.
Collapse
Affiliation(s)
- M Jaber
- Howard Hughes Medical Institute Laboratories, Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Hynie S, Klenerová V, Caicedo M, Samánek M. Differences in response to activation of adenylyl cyclase by various stimulants in human myocardium. Mol Cell Biochem 1996; 163-164:329-33. [PMID: 8974072 DOI: 10.1007/bf00408673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The response of adenylyl cyclase complex in human atrial tissue removed at corrective surgery of normoxemic and hypoxemic congenital heart defects in children to various stimulants was evaluated and related to the oxygenation state of the myocardium. When comparing response to stimulation in normoxemic and hypoxemic atria a higher basal as well as stimulated adenylyl cyclase activity was found in hypoxemic atria; an insignificant stimulatory effect of isoprenaline in normoxemic hearts became significant in the atria of hypoxemic patients. Hypoxemic samples also showed two times higher activity when the total catalytic activity was evaluated by the stimulation with forskolin. Higher stimulatory effect of Gpp/NH/p was also observed in hypoxemic than in normoxemic state. Increased adenylyl cyclase activity might represent one of adaptive mechanisms to hypoxemia in patients with congenital heart defects.
Collapse
Affiliation(s)
- S Hynie
- Institute of Pharmacology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | | | | |
Collapse
|
18
|
Koch WJ, Milano CA, Lefkowitz RJ. Transgenic manipulation of myocardial G protein-coupled receptors and receptor kinases. Circ Res 1996; 78:511-6. [PMID: 8635207 DOI: 10.1161/01.res.78.4.511] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- W J Koch
- Department of Surgery, Duke University Medical Center, Durham, NC, 27710, USA
| | | | | |
Collapse
|
19
|
Lohse MJ, Engelhardt S, Danner S, Böhm M. Mechanisms of beta-adrenergic receptor desensitization: from molecular biology to heart failure. Basic Res Cardiol 1996; 91 Suppl 2:29-34. [PMID: 8957541 DOI: 10.1007/bf00795359] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
beta-Adrenergic receptors are often studied as prototypes of the large family of G-protein-coupled receptors, which includes many other well-known members such as the muscarinic acetylcholine receptors, but also the receptors for light, taste and olfaction. These receptors are regulated by multiple mechanisms which can affect either their function or their expression to a rapidly changing environment. The most obvious changes are effected by receptor agonists, and this process is called receptor desensitization. On the functional level, the most intriguing and important mechanism of desensitization involves the phosphorylation of beta-adrenergic and homologous receptors by specific receptor kinases, termed the G-protein-coupled receptor kinases (GRKs). This phosphorylation is followed by binding of arrestins to the receptors, which causes uncoupling of receptors and G-proteins and thus results in a loss of receptor function. On the expression level, there appear to be two major pathways leading to a reduction of the receptor number: degradation of the receptors themselves, or reduced receptor synthesis brought about by reduced receptor mRNA levels. Heart failure is accompanied by a markedly reduced responsiveness of the beta-adrenergic receptor system, which in many ways resembles the phenomena seen in agonist-induced receptor desensitization. The levels of beta 1-adrenergic receptors are reduced, and this reduction is paralleled by similar decreases in the levels of the corresponding mRNA. At the same time, the activity and the mRNA levels of one of the GRK-isoforms, GRK2 (which is identical to the beta-adrenergic receptor kinase 1) are increased. These alterations may contribute to the loss of beta-adrenergic receptor responsiveness in heart failure and result in further impairment of cardiac function.
Collapse
Affiliation(s)
- M J Lohse
- Institut für Pharmakologie und Toxikologie Universität Würzburg, Germany
| | | | | | | |
Collapse
|
20
|
Igic R. Mechanism of epinephrine-induced dysrhythmias in rat involves local cholinergic activation. Can J Physiol Pharmacol 1996. [DOI: 10.1139/y95-226] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|