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Amoni M, Dries E, Ingelaere S, Vermoortele D, Roderick HL, Claus P, Willems R, Sipido KR. Ventricular Arrhythmias in Ischemic Cardiomyopathy-New Avenues for Mechanism-Guided Treatment. Cells 2021; 10:2629. [PMID: 34685609 PMCID: PMC8534043 DOI: 10.3390/cells10102629] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/13/2022] Open
Abstract
Ischemic heart disease is the most common cause of lethal ventricular arrhythmias and sudden cardiac death (SCD). In patients who are at high risk after myocardial infarction, implantable cardioverter defibrillators are the most effective treatment to reduce incidence of SCD and ablation therapy can be effective for ventricular arrhythmias with identifiable culprit lesions. Yet, these approaches are not always successful and come with a considerable cost, while pharmacological management is often poor and ineffective, and occasionally proarrhythmic. Advances in mechanistic insights of arrhythmias and technological innovation have led to improved interventional approaches that are being evaluated clinically, yet pharmacological advancement has remained behind. We review the mechanistic basis for current management and provide a perspective for gaining new insights that centre on the complex tissue architecture of the arrhythmogenic infarct and border zone with surviving cardiac myocytes as the source of triggers and central players in re-entry circuits. Identification of the arrhythmia critical sites and characterisation of the molecular signature unique to these sites can open avenues for targeted therapy and reduce off-target effects that have hampered systemic pharmacotherapy. Such advances are in line with precision medicine and a patient-tailored therapy.
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Affiliation(s)
- Matthew Amoni
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
- Division of Cardiology, University Hospitals Leuven, 3000 Leuven, Belgium
- Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7935, South Africa
| | - Eef Dries
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
| | - Sebastian Ingelaere
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
- Division of Cardiology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Dylan Vermoortele
- Imaging and Cardiovascular Dynamics, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (D.V.); (P.C.)
| | - H. Llewelyn Roderick
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
| | - Piet Claus
- Imaging and Cardiovascular Dynamics, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (D.V.); (P.C.)
| | - Rik Willems
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
- Division of Cardiology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Karin R. Sipido
- Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium; (M.A.); (E.D.); (S.I.); (H.L.R.); (R.W.)
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Sikkel MB, Francis DP, Howard J, Gordon F, Rowlands C, Peters NS, Lyon AR, Harding SE, MacLeod KT. Hierarchical statistical techniques are necessary to draw reliable conclusions from analysis of isolated cardiomyocyte studies. Cardiovasc Res 2017; 113:1743-1752. [PMID: 29016722 PMCID: PMC5852514 DOI: 10.1093/cvr/cvx151] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/27/2017] [Accepted: 08/29/2017] [Indexed: 02/01/2023] Open
Abstract
AIMS It is generally accepted that post-MI heart failure (HF) changes a variety of aspects of sarcoplasmic reticular Ca2+ fluxes but for some aspects there is disagreement over whether there is an increase or decrease. The commonest statistical approach is to treat data collected from each cell as independent, even though they are really clustered with multiple likely similar cells from each heart. In this study, we test whether this statistical assumption of independence can lead the investigator to draw conclusions that would be considered erroneous if the analysis handled clustering with specific statistical techniques (hierarchical tests). METHODS AND RESULTS Ca2+ transients were recorded in cells loaded with Fura-2AM and sparks were recorded in cells loaded with Fluo-4AM. Data were analysed twice, once with the common statistical approach (assumption of independence) and once with hierarchical statistical methodologies designed to allow for any clustering. The statistical tests found that there was significant hierarchical clustering. This caused the common statistical approach to underestimate the standard error and report artificially small P values. For example, this would have led to the erroneous conclusion that time to 50% peak transient amplitude was significantly prolonged in HF. Spark analysis showed clustering, both within each cell and also within each rat, for morphological variables. This means that a three-level hierarchical model is sometimes required for such measures. Standard statistical methodologies, if used instead, erroneously suggest that spark amplitude is significantly greater in HF and spark duration is reduced in HF. CONCLUSION Ca2+ fluxes in isolated cardiomyocytes show so much clustering that the common statistical approach that assumes independence of each data point will frequently give the false appearance of statistically significant changes. Hierarchical statistical methodologies need a little more effort, but are necessary for reliable conclusions. We present cost-free simple tools for performing these analyses.
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Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Electrophysiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Darrel P Francis
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - James Howard
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Fabiana Gordon
- Statistics Advisory Service, Imperial College London, London, UK
| | - Christina Rowlands
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Nicholas S Peters
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Electrophysiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Alexander R Lyon
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Cardiology, Royal Brompton Hospital, London, UK
| | - Sian E Harding
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Kenneth T MacLeod
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
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Aboelkassem Y. Stokes flow patterns induced by a single cardiac cell. Comput Biol Med 2017; 86:65-74. [PMID: 28511120 DOI: 10.1016/j.compbiomed.2017.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/15/2017] [Accepted: 05/01/2017] [Indexed: 11/27/2022]
Abstract
Stokes flow motions induced by a beating single cardiac cell (cardiomyocyte) are obtained numerically using the method of fundamental solutions (MFS). A two-dimensional meshfree-Stokeslets computational framework is used to solve the Stokes governing equations around an isolated cardiomyocyte. An approximate beating kinematical model is derived and used to approximate the cell-length shortening over a complete cardiac cycle. The induced flow patterns have been found to be characterized by the presence of counter-rotating vortices at both cell's edges. These vortical flow structures are clearly shown by rendering the velocity streamlines. The static pressure contours are also calculated at different time snapshots during both contraction and relaxation phases of the beating motion. The pressure signal is calculated at a point in the neighborhood of cell surface to capture the induced normal stress (traction) by the cell morphological motions to the surrounding fluid medium. The presented results have shown that, cells with a slightly different shortening/beating profile can induce different flow field. This implies that, each cell is characterized by a unique flow pattern "signature", which potentially can be correlated to the sub-cellular excitation-contraction processes of cardiac cells.
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Affiliation(s)
- Yasser Aboelkassem
- Institute for Computational Medicine, Department of Biomedical Engineering Johns Hopkins University, Baltimore, MD 21218, USA.
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4
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Emmens RW, Oedayrajsingh-Varma M, Woudstra L, Kamp O, Meinster E, van Dijk A, Helder MN, Wouters D, Zeerleder S, van Ham SM, de Jong N, Niessen HW, Juffermans LJ, Krijnen PA. A comparison in therapeutic efficacy of several time points of intravenous StemBell administration in a rat model of acute myocardial infarction. Cytotherapy 2017; 19:131-140. [DOI: 10.1016/j.jcyt.2016.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/07/2016] [Accepted: 10/12/2016] [Indexed: 12/21/2022]
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Woudstra L, Krijnen P, Bogaards S, Meinster E, Emmens R, Kokhuis T, Bollen I, Baltzer H, Baart S, Parbhudayal R, Helder M, van Hinsbergh V, Musters R, de Jong N, Kamp O, Niessen H, van Dijk A, Juffermans L. Development of a new therapeutic technique to direct stem cells to the infarcted heart using targeted microbubbles: StemBells. Stem Cell Res 2016; 17:6-15. [DOI: 10.1016/j.scr.2016.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/21/2016] [Accepted: 04/28/2016] [Indexed: 02/07/2023] Open
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Mesenchymal stem cell therapy associated with endurance exercise training: Effects on the structural and functional remodeling of infarcted rat hearts. J Mol Cell Cardiol 2016; 90:111-9. [DOI: 10.1016/j.yjmcc.2015.12.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 11/20/2015] [Accepted: 12/14/2015] [Indexed: 01/16/2023]
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7
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Bozi LHM, Maldonado IRDSC, Baldo MP, Silva MFD, Moreira JBN, Novaes RD, Ramos RMS, Mill JG, Brum PC, Felix LB, Gomes TNP, Natali AJ. Exercise training prior to myocardial infarction attenuates cardiac deterioration and cardiomyocyte dysfunction in rats. Clinics (Sao Paulo) 2013; 68:549-56. [PMID: 23778353 PMCID: PMC3634970 DOI: 10.6061/clinics/2013(04)18] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/05/2012] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The present study was performed to investigate 1) whether aerobic exercise training prior to myocardial infarction would prevent cardiac dysfunction and structural deterioration and 2) whether the potential cardiac benefits of aerobic exercise training would be associated with preserved morphological and contractile properties of cardiomyocytes in post-infarct remodeled myocardium. METHODS Male Wistar rats underwent an aerobic exercise training protocol for eight weeks. The rats were then assigned to sham surgery (SHAM), sedentary lifestyle and myocardial infarction or exercise training and myocardial infarction groups and were evaluated 15 days after the surgery. Left ventricular tissue was analyzed histologically, and the contractile function of isolated myocytes was measured. Student's t-test was used to analyze infarct size and ventricular wall thickness, and the other parameters were analyzed by the Kruskal-Wallis test followed by Dunn's test or a one-way analysis of variance followed by Tukey's test (p<0.05). RESULTS Myocardial infarctions in exercise-trained animals resulted in a smaller myocardial infarction extension, a thicker infarcted wall and less collagen accumulation as compared to myocardial infarctions in sedentary animals. Myocardial infarction-induced left ventricular dilation and cardiac dysfunction, as evaluated by +dP/dt and -dP/dt, were both prevented by previous aerobic exercise training. Moreover, aerobic exercise training preserved cardiac myocyte shortening, improved the maximum shortening and relengthening velocities in infarcted hearts and enhanced responsiveness to calcium. CONCLUSION Previous aerobic exercise training attenuated the cardiac dysfunction and structural deterioration promoted by myocardial infarction, and such benefits were associated with preserved cardiomyocyte morphological and contractile properties.
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8
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Kemi OJ, Hoydal MA, Macquaide N, Haram PM, Koch LG, Britton SL, Ellingsen O, Smith GL, Wisloff U. The effect of exercise training on transverse tubules in normal, remodeled, and reverse remodeled hearts. J Cell Physiol 2011; 226:2235-43. [PMID: 21660947 DOI: 10.1002/jcp.22559] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The response of transverse (T)-tubules to exercise training in health and disease remains unclear. Therefore, we studied the effect of exercise training on the density and spacing of left ventricle cardiomyocyte T-tubules in normal and remodeled hearts that associate with detubulation, by confocal laser scanning microscopy. First, exercise training in normal rats increased cardiomyocyte volume by 16% (P < 0.01), with preserved T-tubule density. Thus, the T-tubules adapted to the physiologic hypertrophy. Next, we studied T-tubules in a rat model of metabolic syndrome with pressure overload-induced concentric left ventricle hypertrophy, evidenced by 15% (P < 0.01) increased cardiomyocyte size. These rats had only 85% (P < 0.01) of the T-tubule density of control rats. Exercise training further increased cardiomyocyte volume by 8% (P < 0.01); half to that in control rats, but the T-tubule density remained unchanged. Finally, post-myocardial infarction heart failure induced severe cardiac pathology, with a 70% (P < 0.01) increased cardiomyocyte volume that included both eccentric and concentric hypertrophy and 55% (P < 0.01) reduced T-tubule density. Exercise training reversed 50% (P < 0.01) of the pathologic hypertrophy, whereas the T-tubule density increased by 40% (P < 0.05) compared to sedentary heart failure, but remained at 60% of normal hearts (P < 0.01). Physiologic hypertrophy associated with conserved T-tubule spacing (~1.8-1.9 µm), whereas in pathologic hypertrophy, T-tubules appeared disorganized without regular spacing. In conclusion, cardiomyocytes maintain the relative T-tubule density during physiologic hypertrophy and after mild concentric pathologic hypertrophy, whereas after severe pathologic remodeling with a substantial loss of T-tubules; exercise training reverses the remodeling and partly corrects the T-tubule density.
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Affiliation(s)
- Ole J Kemi
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Kemi OJ, Wisløff U. Mechanisms of exercise-induced improvements in the contractile apparatus of the mammalian myocardium. Acta Physiol (Oxf) 2010; 199:425-39. [PMID: 20353489 DOI: 10.1111/j.1748-1716.2010.02132.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by and large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function.
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Affiliation(s)
- O J Kemi
- Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK.
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10
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Lancel S, Qin F, Lennon SL, Zhang J, Tong X, Mazzini MJ, Kang YJ, Siwik DA, Cohen RA, Colucci WS. Oxidative posttranslational modifications mediate decreased SERCA activity and myocyte dysfunction in Galphaq-overexpressing mice. Circ Res 2010; 107:228-32. [PMID: 20508180 PMCID: PMC2909347 DOI: 10.1161/circresaha.110.217570] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Myocyte contractile dysfunction occurs in pathological remodeling in association with abnormalities in calcium regulation. Mice with cardiac myocyte-specific overexpression of Galphaq develop progressive left ventricular failure associated with myocyte contractile dysfunction and calcium dysregulation. OBJECTIVE We tested the hypothesis that myocyte contractile dysfunction in the Galphaq mouse heart is mediated by reactive oxygen species, and in particular, oxidative posttranslational modifications, which impair the function of sarcoplasmic reticulum Ca2+-ATPase (SERCA). METHODS AND RESULTS Freshly isolated ventricular myocytes from Galphaq mice had marked abnormalities of myocyte contractile function and calcium transients. In Galphaq myocardium, SERCA protein was not altered in quantity but displayed evidence of oxidative cysteine modifications reflected by decreased biotinylated iodoacetamide labeling and evidence of specific irreversible oxidative modifications consisting of sulfonylation at cysteine 674 and nitration at tyrosines 294/295. Maximal calcium-stimulated SERCA activity was decreased 47% in Galphaq myocardium. Cross-breeding Galphaq mice with transgenic mice that have cardiac myocyte-specific overexpression of catalase (a) decreased SERCA oxidative cysteine modifications, (b) decreased SERCA cysteine 674 sulfonylation and tyrosine 294/295 nitration, (c) restored SERCA activity, and (d) improved myocyte calcium transients and contractile function. CONCLUSIONS In Galphaq-induced cardiomyopathy, myocyte contractile dysfunction is mediated, at least in part, by 1 or more oxidative posttranslational modifications of SERCA. Protein oxidative posttranslational modifications contribute to the pathophysiology of myocardial dysfunction and thus may provide a target for therapeutic intervention.
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MESH Headings
- Animals
- Calcium Signaling
- Catalase/metabolism
- Cells, Cultured
- Cysteine/metabolism
- Disease Models, Animal
- Down-Regulation
- GTP-Binding Protein alpha Subunits, Gq-G11/genetics
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- Mice
- Mice, Transgenic
- Myocardial Contraction
- Myocytes, Cardiac/enzymology
- Oxidation-Reduction
- Protein Processing, Post-Translational
- Reactive Oxygen Species/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
- Up-Regulation
- Ventricular Dysfunction, Left/enzymology
- Ventricular Dysfunction, Left/genetics
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Dysfunction, Left/prevention & control
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Affiliation(s)
- Steve Lancel
- Cardiovascular Medicine Section, Department of Medicine, Boston University Medical Center, 88 E Newton St, Boston, MA 02118, USA
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Abstract
Regular exercise training confers beneficial effects to the heart as well as to the entire body. This occurs partly because exercise training improves skeletal muscle work capacity and reduces resistance, thus increasing conductance in the peripheral circulation. More directly, exercise training also alters extrinsic modulation of the heart and improves the intrinsic pump capacity of the heart. Together, these effects allow for improved exercise capacity. Accumulating evidence suggests that the magnitude of these benefits increases proportionally with the intensity of individual exercise training sessions constituting the exercise training program. It has emerged that regular exercise training also confers beneficial effects to patients at risk for, or who have, established heart dysfunction and disease and, moreover, that exercise training may reduce the dysfunction of the heart itself and, at least, partly restore its ability to effectively function as a pump. The most recent studies in patients with established heart disease suggest that a high relative, yet aerobic, intensity of the exercise training improves the intrinsic pump capacity of the myocardium, an effect not previously believed to occur with exercise training. However, more and larger studies are needed to establish the safety and efficacy of such exercise training in patients with heart disease. Here, we consider the nature of the intensity dependence of exercise training and the causes of the improved heart function.
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Pathological and physiological hypertrophies are regulated by distinct gene programs. ACTA ACUST UNITED AC 2010; 16:690-7. [PMID: 19809332 DOI: 10.1097/hjr.0b013e32833158a2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND This study aims to investigate changes that occur during progression and establishment of physiological and pathological cardiac hypertrophy, by microarray technology and functional annotations. DESIGN AND METHODS Myocardial infarction leading to heart failure was induced in rats, with animals killed 1, 3, 7, 14, 42, and 92 days after coronary artery ligation. A second group was subjected to daily treadmill exercise and killed 1, 4, 24, and 48 h after a single exercise bout, or after 28 or 56 days of exercise training. RESULTS Physiological hypertrophy was associated with less transcriptional alternation than pathological hypertrophy, indicating that posttranscriptional and translational regulation may be more important. The main difference between the two types of hypertrophy was that myocardial infarction was associated with downregulation of genes related to fatty acid metabolism, whereas no such change occurred after exercise training. Thus, fatty acid metabolism may distinguish adverse maladaptive hypertrophy from beneficial adaptive hypertrophy. CONCLUSION This study points to specific genes and gene classes related to biological processes that may be important in these well-characterized rat models of physiological and pathological cardiac hypertrophy.
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Giraud MN, Liechti EF, Tchantchaleishvili V, Siepe M, Cook S, Carrel TP, Tevaearai HT. Myocardial injection of skeletal myoblasts impairs contractility of host cardiomyocytes. Int J Cardiol 2008; 138:131-7. [PMID: 18809218 DOI: 10.1016/j.ijcard.2008.08.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2007] [Revised: 04/10/2008] [Accepted: 08/08/2008] [Indexed: 01/08/2023]
Abstract
BACKGROUND Mechanisms underlying improvement of myocardial contractile function after cell therapy as well as arrhythmic side effect remain poorly understood. We hypothesised that cell therapy might affect the mechanical properties of isolated host cardiomyocytes. METHODS Two weeks after myocardial infarction (MI), rats were treated by intramyocardial myoblast injection (SkM, n=8), intramyocardial vehicle injection (Medium, n=6), or sham operation (Sham, n=7). Cardiac function was assessed by echocardiography. Cardiomyocytes were isolated in a modified Langendorff perfusion system, their contraction was measured by video-based inter-sarcomeric analysis. Data were compared with a control-group without myocardial infarction (Control, n=5). RESULTS Three weeks post-treatment, ejection fraction (EF) further deteriorated in vehicle-injected and non-injected rats (respectively 40.7+/-11.4% to 33+/-5.5% and 41.8+/-8% to 33.5+/-8.3%), but was stabilised in SkM group (35.9+/-6% to 36.4+/-9.7%). Significant cell hypertrophy induced by MI was maintained after cell therapy. Single cell contraction (dL/dt(max)) decreased in SkM and vehicle groups compared to non-injected group as well as cell shortening and relaxation (dL/dt(min)) in vehicle group. A significantly increased predisposition for alternation of strong and weak contractions was observed in isolated cardiomyocytes of the SkM group. CONCLUSION Our study provides the first evidence that injection of materials into the myocardium alters host cardiomyocytes contractile function independently of the global beneficial effect of the heart function. These findings may be important in understanding possible adverse effects.
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Slow contractions characterize failing rat hearts. Basic Res Cardiol 2008; 103:328-44. [DOI: 10.1007/s00395-008-0719-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 02/08/2008] [Indexed: 10/22/2022]
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Soppa GKR, Lee J, Stagg MA, Felkin LE, Barton PJR, Siedlecka U, Youssef S, Yacoub MH, Terracciano CMN. Role and possible mechanisms of clenbuterol in enhancing reverse remodelling during mechanical unloading in murine heart failure. Cardiovasc Res 2008; 77:695-706. [PMID: 18178572 PMCID: PMC5436743 DOI: 10.1093/cvr/cvm106] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aims Combined left ventricular assist device (LVAD) and pharmacological therapy has been proposed to favour myocardial recovery in patients with end-stage heart failure (HF). Clenbuterol (Clen), a β2-adrenoceptor (β2-AR) agonist, has been used as a part of this strategy. In this study, we investigated the direct effects of clenbuterol on unloaded myocardium in HF. Methods and results Left coronary artery ligation or sham operation was performed in male Lewis rats. After 4–6 weeks, heterotopic abdominal transplantation of the failing hearts into normal recipients was performed to induce LV unloading (UN). Recipient rats were treated with saline (Sal) or clenbuterol (2 mg/kg/day) via osmotic minipumps (HF + UN + Sal or HF + UN + Clen) for 7 days. Non-transplanted HF animals were treated with Sal (Sham + Sal, HF + Sal) or clenbuterol (HF + Clen). LV myocytes were isolated and studied using optical, fluorescence, and electrophysiological techniques. Clenbuterol treatment improved in vivo LV function measured with echocardiography (LVEF (%): HF 35.9 ± 2 [16], HF + Clen 52.1 ± 1.4 [16]; P < 0.001; mean ± SEM [n]). In combination with unloading, clenbuterol increased sarcomere shortening (amplitude (µm): HF + UN + Clen 0.1 ± 0.01 [50], HF + UN + Sal 0.07 ± 0.01 [38]; P < 0.001) by normalizing the depressed myofilament sensitivity to Ca2+ (slope of the linear relationship between Ca2+ transient and sarcomere shortening hysteresis loop during relaxation (μm/ratio unit): HF + UN + Clen 2.13 ± 0.2 [52], HF + UN + Sal 1.42 ± 0.13 [38]; P < 0.05). Conclusion Clenbuterol treatment of failing rat hearts, alone or in combination with mechanical unloading, improves LV function at the whole-heart and cellular levels by affecting cell morphology, excitation–contraction coupling, and myofilament sensitivity to calcium. This study supports the use of this drug in the strategy to enhance recovery in HF patients treated with LVADs and also begins to elucidate some of the possible cellular mechanisms responsible for the improvement in LV function.
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Affiliation(s)
- Gopal K R Soppa
- Heart Science Centre, Imperial College London, National Heart and Lung Institute, Laboratory of Cellular Electrophysiology, Harefield Hospital, Harefield, Middlesex, UK
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Kemi OJ, Haram PM, Wisløff U, Ellingsen Ø. Aerobic fitness is associated with cardiomyocyte contractile capacity and endothelial function in exercise training and detraining. Circulation 2004; 109:2897-904. [PMID: 15173028 DOI: 10.1161/01.cir.0000129308.04757.72] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Physical fitness and level of regular exercise are closely related to cardiovascular health. A regimen of regular intensity-controlled treadmill exercise was implemented and withdrawn to identify cellular mechanisms associated with exercise capacity and maximal oxygen uptake (VO2max). METHODS AND RESULTS Time-dependent associations between cardiomyocyte dimensions, contractile capacity, and VO2max were assessed in adult rats after high-level intensity-controlled treadmill running for 2, 4, 8, and 13 weeks and detraining for 2 and 4 weeks. With training, cardiomyocyte length, relaxation, shortening, Ca2+ decay, and estimated cell volume correlated with increased VO2max (r=0.92, -0.92, 0.88, -0.84, 0.73; P<0.01). Multiple regression analysis identified cell length, relaxation, and Ca2+ decay as the main explanatory variables for VO2max (R2=0.87, P<0.02). When training stopped, exercise-gained VO2max decreased 50% within 2 weeks and stabilized at 5% above sedentary controls after 4 weeks. Cardiomyocyte size regressed in parallel with VO2max and remained (9%) above sedentary after 4 weeks, whereas cardiomyocyte shortening, contraction/relaxation- and Ca2+-transient time courses, and endothelium-dependent vasorelaxation regressed completely within 2 to 4 weeks of detraining. Cardiomyocyte length, estimated cell volume, width, shortening, and Ca2+ decay and endothelium-dependent arterial relaxation all correlated with VO2max (r=0.85, 0.84, 0.75, 0.63, -0.54, -0.37; P<0.01). Multiple regression identified cardiomyocyte length and vasorelaxation as the main determinants for regressed VO2max during detraining (R2=0.76, P=0.02). CONCLUSIONS Cardiovascular adaptation to regular exercise is highly dynamic. On detraining, most of the exercise-gained aerobic fitness acquired over 2 to 3 months is lost within 2 to 4 weeks. The close association between cardiomyocyte dimensions, contractile capacity, arterial relaxation, and aerobic fitness suggests cellular mechanisms underlying these changes.
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Affiliation(s)
- Ole Johan Kemi
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
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Hoshijima M. Models of Dilated Cardiomyopathy in Small Animals and Novel Positive Inotropic Therapies. Ann N Y Acad Sci 2004; 1015:320-31. [PMID: 15201171 DOI: 10.1196/annals.1302.028] [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] [Indexed: 01/08/2023]
Abstract
Several randomized clinical trials of vesnarinone and milrinone in patients with heart failure left disappointing results in the 1990s. Thereafter, use of positive inotropic agents has been avoided. Exceptions are the use of digitalis glycosides to treat mild-moderate heart failure and the intravenous administration of catecholamines and phosphodiesterase inhibitors in patients with acute and/or refractory heart failure. It is not, however, exactly known whether chronic enhancement of cardiac contractility indeed has harmful effects, besides increased risk of arrhythmia and mortality. We investigated the potential chronic benefit of positive inotropic modification to treat progressive cardiomyopathy and associated heart failure using a genetic complementation strategy of muscle lim-protein and phospholamban (PLN) double mutagenesis in the mouse and found clear evidence of positive effects. Subsequent somatic modification of PLN function via gene transfer with recombinant adeno-associated virus vectors in small animal models of dilated cardiomyopathy further supported the chronic benefit of enhanced cardiac function achieved in an beta-adrenergic stimulus-independent manner. This study examines current small animal models of dilated cardiomyopathy and recent multiple attempts to use these models as novel gene-based inotropic therapies.
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Affiliation(s)
- Masahiko Hoshijima
- Institute of Molecular Medicine, Department of Medicine, University of California San Diego School of Medicine, La Jolla, CA 92093, USA.
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Hoshijima M, Pashmforoush M, Knöll R, Chien KR. The MLP family of cytoskeletal Z disc proteins and dilated cardiomyopathy: a stress pathway model for heart failure progression. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 67:399-408. [PMID: 12858565 DOI: 10.1101/sqb.2002.67.399] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- M Hoshijima
- Institute of Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA
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