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Sun Q, Güven B, Wagg CS, Almeida de Oliveira A, Silver H, Zhang L, Chen B, Wei K, Ketema EB, Karwi QG, Persad KL, Vu J, Wang F, Dyck JRB, Oudit GY, Lopaschuk GD. Mitochondrial fatty acid oxidation is the major source of cardiac adenosine triphosphate production in heart failure with preserved ejection fraction. Cardiovasc Res 2024; 120:360-371. [PMID: 38193548 DOI: 10.1093/cvr/cvae006] [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: 08/31/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 01/10/2024] Open
Abstract
AIMS Heart failure with preserved ejection fraction (HFpEF) is a prevalent disease worldwide. While it is well established that alterations of cardiac energy metabolism contribute to cardiovascular pathology, the precise source of fuel used by the heart in HFpEF remains unclear. The objective of this study was to define the energy metabolic profile of the heart in HFpEF. METHODS AND RESULTS Eight-week-old C57BL/6 male mice were subjected to a '2-Hit' HFpEF protocol [60% high-fat diet (HFD) + 0.5 g/L of Nω-nitro-L-arginine methyl ester]. Echocardiography and pressure-volume loop analysis were used for assessing cardiac function and cardiac haemodynamics, respectively. Isolated working hearts were perfused with radiolabelled energy substrates to directly measure rates of fatty acid oxidation, glucose oxidation, ketone oxidation, and glycolysis. HFpEF mice exhibited increased body weight, glucose intolerance, elevated blood pressure, diastolic dysfunction, and cardiac hypertrophy. In HFpEF hearts, insulin stimulation of glucose oxidation was significantly suppressed. This was paralleled by an increase in fatty acid oxidation rates, while cardiac ketone oxidation and glycolysis rates were comparable with healthy control hearts. The balance between glucose and fatty acid oxidation contributing to overall adenosine triphosphate (ATP) production was disrupted, where HFpEF hearts were more reliant on fatty acid as the major source of fuel for ATP production, compensating for the decrease of ATP originating from glucose oxidation. Additionally, phosphorylated pyruvate dehydrogenase levels decreased in both HFpEF mice and human patient's heart samples. CONCLUSION In HFpEF, fatty acid oxidation dominates as the major source of cardiac ATP production at the expense of insulin-stimulated glucose oxidation.
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Affiliation(s)
- Qiuyu Sun
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Berna Güven
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Faculty of Pharmacy, Department of Pharmacology, Ankara University, Ankara, Turkey
| | - Cory S Wagg
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Amanda Almeida de Oliveira
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada
| | - Heidi Silver
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Liyan Zhang
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Brandon Chen
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Kaleigh Wei
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
| | - Ezra B Ketema
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Qutuba G Karwi
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, Saint John's, Canada
| | - Kaya L Persad
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Jennie Vu
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada
| | - Faqi Wang
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada
| | - Jason R B Dyck
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Gavin Y Oudit
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Canada
| | - Gary D Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada
- Department of Pediatrics, University of Alberta, Edmonton, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
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2
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Sun Q, Wagg CS, Güven B, Wei K, de Oliveira AA, Silver H, Zhang L, Vergara A, Chen B, Wong N, Wang F, Dyck JRB, Oudit GY, Lopaschuk GD. Stimulating cardiac glucose oxidation lessens the severity of heart failure in aged female mice. Basic Res Cardiol 2024; 119:133-150. [PMID: 38148348 DOI: 10.1007/s00395-023-01020-2] [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: 09/27/2023] [Revised: 10/30/2023] [Accepted: 10/31/2023] [Indexed: 12/28/2023]
Abstract
Heart failure is a prevalent disease worldwide. While it is well accepted that heart failure involves changes in myocardial energetics, what alterations that occur in fatty acid oxidation and glucose oxidation in the failing heart remains controversial. The goal of the study are to define the energy metabolic profile in heart failure induced by obesity and hypertension in aged female mice, and to attempt to lessen the severity of heart failure by stimulating myocardial glucose oxidation. 13-Month-old C57BL/6 female mice were subjected to 10 weeks of a 60% high-fat diet (HFD) with 0.5 g/L of Nω-nitro-L-arginine methyl ester (L-NAME) administered via drinking water to induce obesity and hypertension. Isolated working hearts were perfused with radiolabeled energy substrates to directly measure rates of myocardial glucose oxidation and fatty acid oxidation. Additionally, a series of mice subjected to the obesity and hypertension protocol were treated with a pyruvate dehydrogenase kinase inhibitor (PDKi) to stimulate cardiac glucose oxidation. Aged female mice subjected to the obesity and hypertension protocol had increased body weight, glucose intolerance, elevated blood pressure, cardiac hypertrophy, systolic dysfunction, and decreased survival. While fatty acid oxidation rates were not altered in the failing hearts, insulin-stimulated glucose oxidation rates were markedly impaired. PDKi treatment increased cardiac glucose oxidation in heart failure mice, which was accompanied with improved systolic function and decreased cardiac hypertrophy. The primary energy metabolic change in heart failure induced by obesity and hypertension in aged female mice is a dramatic decrease in glucose oxidation. Stimulating glucose oxidation can lessen the severity of heart failure and exert overall functional benefits.
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Affiliation(s)
- Qiuyu Sun
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Cory S Wagg
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Berna Güven
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Kaleigh Wei
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Amanda A de Oliveira
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Heidi Silver
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Liyan Zhang
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Ander Vergara
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Brandon Chen
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Nathan Wong
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Faqi Wang
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Jason R B Dyck
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada
| | - Gavin Y Oudit
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada
| | - Gary D Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada.
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB, Canada.
- Department of Pediatrics, University of Alberta, Edmonton, AB, T6G 2S2, Canada.
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Vite A, Matsuura TR, Bedi KC, Flam EL, Arany Z, Kelly DP, Margulies KB. Functional Impact of Alternative Metabolic Substrates in Failing Human Cardiomyocytes. JACC Basic Transl Sci 2024; 9:1-15. [PMID: 38362346 PMCID: PMC10864907 DOI: 10.1016/j.jacbts.2023.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 07/10/2023] [Accepted: 07/10/2023] [Indexed: 02/17/2024]
Abstract
Recent studies suggest that metabolic dysregulation in patients with heart failure might contribute to myocardial contractile dysfunction. To understand the correlation between function and energy metabolism, we studied the impact of different fuel substrates on human nonfailing or failing cardiomyocytes. Consistent with the concept of metabolic flexibility, nonfailing myocytes exhibited excellent contractility in all fuels provided. However, impaired contractility was observed in failing myocytes when carbohydrates alone were used but was improved when additional substrates were added. This study demonstrates the functional significance of fuel utilization shifts in failing human cardiomyocytes.
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Affiliation(s)
- Alexia Vite
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Timothy R. Matsuura
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kenneth C. Bedi
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Emily L. Flam
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Zoltan Arany
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel P. Kelly
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kenneth B. Margulies
- Cardiovascular Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Wei J, Duan X, Chen J, Zhang D, Xu J, Zhuang J, Wang S. Metabolic adaptations in pressure overload hypertrophic heart. Heart Fail Rev 2024; 29:95-111. [PMID: 37768435 DOI: 10.1007/s10741-023-10353-y] [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: 09/19/2023] [Indexed: 09/29/2023]
Abstract
This review article offers a detailed examination of metabolic adaptations in pressure overload hypertrophic hearts, a condition that plays a pivotal role in the progression of heart failure with preserved ejection fraction (HFpEF) to heart failure with reduced ejection fraction (HFrEF). The paper delves into the complex interplay between various metabolic pathways, including glucose metabolism, fatty acid metabolism, branched-chain amino acid metabolism, and ketone body metabolism. In-depth insights into the shifts in substrate utilization, the role of different transporter proteins, and the potential impact of hypoxia-induced injuries are discussed. Furthermore, potential therapeutic targets and strategies that could minimize myocardial injury and promote cardiac recovery in the context of pressure overload hypertrophy (POH) are examined. This work aims to contribute to a better understanding of metabolic adaptations in POH, highlighting the need for further research on potential therapeutic applications.
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Affiliation(s)
- Jinfeng Wei
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Xuefei Duan
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jiaying Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Dengwen Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jindong Xu
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jian Zhuang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
| | - Sheng Wang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
- Linzhi People's Hospital, Linzhi, Tibet, China.
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5
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Ritterhoff J, Tian R. Metabolic mechanisms in physiological and pathological cardiac hypertrophy: new paradigms and challenges. Nat Rev Cardiol 2023; 20:812-829. [PMID: 37237146 DOI: 10.1038/s41569-023-00887-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/02/2023] [Indexed: 05/28/2023]
Abstract
Cardiac metabolism is vital for heart function. Given that cardiac contraction requires a continuous supply of ATP in large quantities, the role of fuel metabolism in the heart has been mostly considered from the perspective of energy production. However, the consequence of metabolic remodelling in the failing heart is not limited to a compromised energy supply. The rewired metabolic network generates metabolites that can directly regulate signalling cascades, protein function, gene transcription and epigenetic modifications, thereby affecting the overall stress response of the heart. In addition, metabolic changes in both cardiomyocytes and non-cardiomyocytes contribute to the development of cardiac pathologies. In this Review, we first summarize how energy metabolism is altered in cardiac hypertrophy and heart failure of different aetiologies, followed by a discussion of emerging concepts in cardiac metabolic remodelling, that is, the non-energy-generating function of metabolism. We highlight challenges and open questions in these areas and finish with a brief perspective on how mechanistic research can be translated into therapies for heart failure.
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Affiliation(s)
- Julia Ritterhoff
- Molecular and Translational Cardiology, Department of Internal Medicine III, Heidelberg University Hospital, Heidelberg, Germany.
- Mitochondria and Metabolism Center, Department of Anaesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA.
| | - Rong Tian
- Mitochondria and Metabolism Center, Department of Anaesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA.
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6
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Stacpoole PW, McCall CE. The pyruvate dehydrogenase complex: Life's essential, vulnerable and druggable energy homeostat. Mitochondrion 2023; 70:59-102. [PMID: 36863425 DOI: 10.1016/j.mito.2023.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/30/2023] [Accepted: 02/13/2023] [Indexed: 03/04/2023]
Abstract
Found in all organisms, pyruvate dehydrogenase complexes (PDC) are the keystones of prokaryotic and eukaryotic energy metabolism. In eukaryotic organisms these multi-component megacomplexes provide a crucial mechanistic link between cytoplasmic glycolysis and the mitochondrial tricarboxylic acid (TCA) cycle. As a consequence, PDCs also influence the metabolism of branched chain amino acids, lipids and, ultimately, oxidative phosphorylation (OXPHOS). PDC activity is an essential determinant of the metabolic and bioenergetic flexibility of metazoan organisms in adapting to changes in development, nutrient availability and various stresses that challenge maintenance of homeostasis. This canonical role of the PDC has been extensively probed over the past decades by multidisciplinary investigations into its causal association with diverse physiological and pathological conditions, the latter making the PDC an increasingly viable therapeutic target. Here we review the biology of the remarkable PDC and its emerging importance in the pathobiology and treatment of diverse congenital and acquired disorders of metabolic integration.
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Affiliation(s)
- Peter W Stacpoole
- Department of Medicine (Division of Endocrinology, Metabolism and Diabetes), and Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, FL, United States.
| | - Charles E McCall
- Department of Internal Medicine and Translational Sciences, and Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
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Pepine CJ. ANOCA/INOCA/MINOCA: Open artery ischemia. AMERICAN HEART JOURNAL PLUS : CARDIOLOGY RESEARCH AND PRACTICE 2023; 26:100260. [PMID: 37064505 PMCID: PMC10104448 DOI: 10.1016/j.ahjo.2023.100260] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Ischemic heart disease continues to represent a major health threat for death, disability, and poor quality of life as it also consumes enormous health-related resources. For over a century, the major clinical phenotype was taken to be obstructive atherosclerosis involving the larger coronary arteries (e.g., coronary artery disease [CAD]). However, evolving evidence now indicates that nonobstructive CAD is the predominant phenotype. Patients within this phenotype have been termed to have angina with no obstructive CAD (ANOCA), ischemia with no obstructive CAD (INOCA), or myocardial infarction with no obstructive coronary arteries (MINOCA). But as methods to assess cardiomyocyte injury evolve, these phenotypic distinctions have begun to merge, raising concern about their usefulness. Also, considerable evidence has suggested several endotypes that link to potential mechanisms. These include coronary microvascular dysfunction, augmented vasoreactivity (failure to relax appropriately, exaggerated constriction ["spasm"], etc.), nonobstructive atherosclerosis, pre-heart failure with preserved ejection fraction, hypercoagulable states, and several others, alone or in combination. This review summarizes these syndromes and their associated clinical outcomes with an emphasis on potential mechanistic signals. These involve the endothelium, the microvasculature, and cardiomyocyte function. Biomarkers of injury/dysfunction involving these structures are discussed along with a hypothetical construct for management being tested in an ongoing trial.
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Affiliation(s)
- Carl J. Pepine
- 1329 SW 16th St, P.O. Box 100288, Gainesville, FL 32610-0288, United States of America.
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8
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Abstract
PURPOSE OF REVIEW Myocardial metabolism is intricately linked to cardiac function. Perturbations of cardiac energy metabolism result in an energy-starved heart and the development of contractile dysfunction. In this review, we discuss alterations in myocardial energy supply, transcriptional changes in response to different energy demands, and mitochondrial function in the development of heart failure. RECENT FINDINGS Recent studies on substrate modulation through modifying energy substrate supply have shown cardioprotective properties. In addition, large cardiovascular outcome trials of anti-diabetic agents have demonstrated prognostic benefit, suggesting the importance of myocardial metabolism in cardiac function. Understanding molecular and transcriptional controls of cardiac metabolism promises new research avenues for metabolic treatment targets. Future studies assessing the impact of substrate modulation on cardiac energetic status and function will better inform development of metabolic therapies.
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Affiliation(s)
- Sher May Ng
- Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK
| | - Stefan Neubauer
- Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK
- Department of Cardiology, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Oliver J Rider
- Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, Oxford, UK.
- Department of Cardiology, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
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9
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Ho KL, Karwi QG, Connolly D, Pherwani S, Ketema EB, Ussher JR, Lopaschuk GD. Metabolic, structural and biochemical changes in diabetes and the development of heart failure. Diabetologia 2022; 65:411-423. [PMID: 34994805 DOI: 10.1007/s00125-021-05637-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/28/2021] [Indexed: 12/21/2022]
Abstract
Diabetes contributes to the development of heart failure through various metabolic, structural and biochemical changes. The presence of diabetes increases the risk for the development of cardiovascular disease (CVD), and since the introduction of cardiovascular outcome trials to test diabetic drugs, the importance of improving our understanding of the mechanisms by which diabetes increases the risk for heart failure has come under the spotlight. In addition to the coronary vasculature changes that predispose individuals with diabetes to coronary artery disease, diabetes can also lead to cardiac dysfunction independent of ischaemic heart disease. The hyperlipidaemic, hyperglycaemic and insulin resistant state of diabetes contributes to a perturbed energy metabolic milieu, whereby the heart increases its reliance on fatty acids and decreases glucose oxidative rates. In addition to changes in cardiac energy metabolism, extracellular matrix remodelling contributes to the development of cardiac fibrosis, and impairments in calcium handling result in cardiac contractile dysfunction. Lipotoxicity and glucotoxicity also contribute to impairments in vascular function, cardiac contractility, calcium signalling, oxidative stress, cardiac efficiency and lipoapoptosis. Lastly, changes in protein acetylation, protein methylation and DNA methylation contribute to a myriad of gene expression and protein activity changes. Altogether, these changes lead to decreased cardiac efficiency, increased vulnerability to an ischaemic insult and increased risk for the development of heart failure. This review explores the above mechanisms and the way in which they contribute to cardiac dysfunction in diabetes.
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Affiliation(s)
- Kim L Ho
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Qutuba G Karwi
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - David Connolly
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Simran Pherwani
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Ezra B Ketema
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - John R Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Gary D Lopaschuk
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
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10
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Perez DM. Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure. Int J Mol Sci 2021; 22:5783. [PMID: 34071350 PMCID: PMC8198887 DOI: 10.3390/ijms22115783] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
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11
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Abstract
Alterations in cardiac energy metabolism contribute to the severity of heart failure. However, the energy metabolic changes that occur in heart failure are complex and are dependent not only on the severity and type of heart failure present but also on the co-existence of common comorbidities such as obesity and type 2 diabetes. The failing heart faces an energy deficit, primarily because of a decrease in mitochondrial oxidative capacity. This is partly compensated for by an increase in ATP production from glycolysis. The relative contribution of the different fuels for mitochondrial ATP production also changes, including a decrease in glucose and amino acid oxidation, and an increase in ketone oxidation. The oxidation of fatty acids by the heart increases or decreases, depending on the type of heart failure. For instance, in heart failure associated with diabetes and obesity, myocardial fatty acid oxidation increases, while in heart failure associated with hypertension or ischemia, myocardial fatty acid oxidation decreases. Combined, these energy metabolic changes result in the failing heart becoming less efficient (ie, a decrease in cardiac work/O2 consumed). The alterations in both glycolysis and mitochondrial oxidative metabolism in the failing heart are due to both transcriptional changes in key enzymes involved in these metabolic pathways, as well as alterations in NAD redox state (NAD+ and nicotinamide adenine dinucleotide levels) and metabolite signaling that contribute to posttranslational epigenetic changes in the control of expression of genes encoding energy metabolic enzymes. Alterations in the fate of glucose, beyond flux through glycolysis or glucose oxidation, also contribute to the pathology of heart failure. Of importance, pharmacological targeting of the energy metabolic pathways has emerged as a novel therapeutic approach to improving cardiac efficiency, decreasing the energy deficit and improving cardiac function in the failing heart.
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Affiliation(s)
- Gary D Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada (G.D.L., Q.G.K.)
| | - Qutuba G Karwi
- Cardiovascular Research Centre, University of Alberta, Edmonton, Canada (G.D.L., Q.G.K.)
| | - Rong Tian
- Mitochondria and Metabolism Center, University of Washington, Seattle (R.T.)
| | - Adam R Wende
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham (A.R.W.)
| | - E Dale Abel
- Division of Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City (E.D.A.).,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City (E.D.A.)
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12
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Pasqua T, Rocca C, Giglio A, Angelone T. Cardiometabolism as an Interlocking Puzzle between the Healthy and Diseased Heart: New Frontiers in Therapeutic Applications. J Clin Med 2021; 10:721. [PMID: 33673114 PMCID: PMC7918460 DOI: 10.3390/jcm10040721] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/14/2022] Open
Abstract
Cardiac metabolism represents a crucial and essential connecting bridge between the healthy and diseased heart. The cardiac muscle, which may be considered an omnivore organ with regard to the energy substrate utilization, under physiological conditions mainly draws energy by fatty acids oxidation. Within cardiomyocytes and their mitochondria, through well-concerted enzymatic reactions, substrates converge on the production of ATP, the basic chemical energy that cardiac muscle converts into mechanical energy, i.e., contraction. When a perturbation of homeostasis occurs, such as an ischemic event, the heart is forced to switch its fatty acid-based metabolism to the carbohydrate utilization as a protective mechanism that allows the maintenance of its key role within the whole organism. Consequently, the flexibility of the cardiac metabolic networks deeply influences the ability of the heart to respond, by adapting to pathophysiological changes. The aim of the present review is to summarize the main metabolic changes detectable in the heart under acute and chronic cardiac pathologies, analyzing possible therapeutic targets to be used. On this basis, cardiometabolism can be described as a crucial mechanism in keeping the physiological structure and function of the heart; furthermore, it can be considered a promising goal for future pharmacological agents able to appropriately modulate the rate-limiting steps of heart metabolic pathways.
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Affiliation(s)
- Teresa Pasqua
- Department of Health Science, University Magna Graecia of Catanzaro, 88100 Catanzaro, Italy;
| | - Carmine Rocca
- Laboratory of Cellular and Molecular Cardiovascular Pathophysiology, Department of Biology, E. and E.S. (Di.B.E.S.T.), University of Calabria, 87036 Rende (CS), Italy
| | - Anita Giglio
- Department of Biology, E. and E.S. (Di.B.E.S.T.), University of Calabria, 87036 Rende (CS), Italy;
| | - Tommaso Angelone
- Laboratory of Cellular and Molecular Cardiovascular Pathophysiology, Department of Biology, E. and E.S. (Di.B.E.S.T.), University of Calabria, 87036 Rende (CS), Italy
- National Institute of Cardiovascular Research (I.N.R.C.), 40126 Bologna, Italy
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Papay RS, Perez DM. α 1-Adrenergic receptors increase glucose oxidation under normal and ischemic conditions in adult mouse cardiomyocytes. J Recept Signal Transduct Res 2020; 41:138-144. [PMID: 32757689 DOI: 10.1080/10799893.2020.1799291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The role of catecholamine receptors in cardiac energy metabolism is unknown. α1-adrenergic receptors (α1-ARs) have been identified to play a role in whole body metabolism but its role in cardiac energy metabolism has not been explored. We used freshly prepared primary adult mouse cardiomyocytes and incubated with either 14C-palmitate or 14C-glucose tracers to measure oxidation rates in the presence or absence of phenylephrine, an α1-AR agonist (with β and α2-AR blockers) under normal cell culture conditions. 14CO2 released was collected over a 10 min period in covered tissue culture plates using a 1 M hyamine hydroxide solution placed in well cups, counted by scintillation and converted into nmoles/hr. We found that phenylephrine stimulated glucose oxidation but not fatty acid oxidation in adult primary cardiomyocytes. α1-AR stimulated glucose oxidation was blocked by the AMPK inhibitor, dorsomorphin dihydrochloride, and the PKC inhibitor, rottlerin. Ischemic conditions were induced by lowering the glucose concentration from 22.5 mM to 1.375 mM. Under ischemic conditions, we found that phenylephrine also increased glucose oxidation. We report a direct role of α1-ARs in regulating glucose oxidation under normal and ischemic conditions that may lead to new therapeutic approaches in treating ischemia.
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Affiliation(s)
- Robert S Papay
- The Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Dianne M Perez
- The Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, USA
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14
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Barton GP, Macdonald EB, Goss KN, Eldridge MW, Fain SB. Measuring the link between cardiac mechanical function and metabolism during hyperpolarized 13C-pyruvate magnetic resonance experiments. Magn Reson Imaging 2020; 68:9-17. [PMID: 31978518 PMCID: PMC7131884 DOI: 10.1016/j.mri.2020.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/19/2019] [Accepted: 01/19/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE The goal of this study was to develop a methodology to investigate the relationship between contractile function and hyperpolarized (HP) [1-13C]pyruvate metabolism in a small animal model. To achieve sufficient signal from HP 13C compounds, HP 13C MRS/MRSI has required relatively large infusion volumes relative to the total blood volume in small animal models, which may affect cardiac function. METHODS Eight female Sprague Dawley rats were imaged on a 4.7T scanner with a dual tuned 1H/13C volume coil. ECG and respiratory gated k-t spiral MRSI and an IDEAL based reconstruction to determine [1-13C]pyruvate metabolism in the myocardium. This was coupled with 1H cine MRI to determine ventricular volumes and mechanical function pre- and post-infusion of [1-13C]pyruvate. For comparison to the [1-13C]pyruvate experiments, three female Sprague Dawley rats were imaged with 1H cine MRI to determine myocardial function pre- and post-saline infusion. RESULTS We demonstrated significant changes in cardiac contractile function between pre- and post-infusion of [1-13C]pyruvate. Specifically, there was an increase in end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF). Additionally, the ventricular vascular coupling ratio (VVCR) showed an improvement after [1-13C]pyruvate infusion, indicating increased systolic performance due to an increased arterial load. There was a moderate to strong relationship between the downstream metabolic conversion of pyruvate to bicarbonate and a strong relationship between the conversion of pyruvate to lactate and the cardiac mechanical function response. CONCLUSION The infusion of [1-13C]pyruvate resulted in demonstrable increases in contractile function which was related to pyruvate conversion to bicarbonate and lactate. The combined effects of the infusion volume and inotropic effects of pyruvate metabolism likely explains the augmentation in myocardial mechanical function seen in these experiments. Given the relationship between pyruvate metabolism and contractile function observed in this study, this methodological approach may be utilized to better understand cardiac metabolic and functional remodeling in heart disease.
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Affiliation(s)
| | | | - Kara N Goss
- Medicine University of Wisconsin, Madison, WI, USA; Pediatrics University of Wisconsin, Madison, WI, USA
| | - Marlowe W Eldridge
- Pediatrics University of Wisconsin, Madison, WI, USA; Biomedical Engineering, University of Wisconsin, Madison, WI, USA
| | - Sean B Fain
- Medical Physics, University of Wisconsin, Madison, WI, USA; Biomedical Engineering, University of Wisconsin, Madison, WI, USA; Radiology, University of Wisconsin, Madison, WI, USA.
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15
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Abstract
Metabolic pathways integrate to support tissue homeostasis and to prompt changes in cell phenotype. In particular, the heart consumes relatively large amounts of substrate not only to regenerate ATP for contraction but also to sustain biosynthetic reactions for replacement of cellular building blocks. Metabolic pathways also control intracellular redox state, and metabolic intermediates and end products provide signals that prompt changes in enzymatic activity and gene expression. Mounting evidence suggests that the changes in cardiac metabolism that occur during development, exercise, and pregnancy as well as with pathological stress (eg, myocardial infarction, pressure overload) are causative in cardiac remodeling. Metabolism-mediated changes in gene expression, metabolite signaling, and the channeling of glucose-derived carbon toward anabolic pathways seem critical for physiological growth of the heart, and metabolic inefficiency and loss of coordinated anabolic activity are emerging as proximal causes of pathological remodeling. This review integrates knowledge of different forms of cardiac remodeling to develop general models of how relationships between catabolic and anabolic glucose metabolism may fortify cardiac health or promote (mal)adaptive myocardial remodeling. Adoption of conceptual frameworks based in relational biology may enable further understanding of how metabolism regulates cardiac structure and function.
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Affiliation(s)
- Andrew A Gibb
- From the Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA (A.A.G.)
| | - Bradford G Hill
- the Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville School of Medicine, KY (B.G.H.).
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Affiliation(s)
- Diem H Tran
- 1 Division of Cardiology Department of Internal Medicine University of Texas Southwestern Medical Center Dallas TX
| | - Zhao V Wang
- 1 Division of Cardiology Department of Internal Medicine University of Texas Southwestern Medical Center Dallas TX
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17
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Adaptations in Protein Expression and Regulated Activity of Pyruvate Dehydrogenase Multienzyme Complex in Human Systolic Heart Failure. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4532592. [PMID: 30881593 PMCID: PMC6383428 DOI: 10.1155/2019/4532592] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/13/2018] [Accepted: 12/18/2018] [Indexed: 01/18/2023]
Abstract
Pyruvate dehydrogenase (PDH) complex, a multienzyme complex at the nexus of glycolytic and Krebs cycles, provides acetyl-CoA to the Krebs cycle and NADH to complex I thus supporting a critical role in mitochondrial energy production and cellular survival. PDH activity is regulated by pyruvate dehydrogenase phosphatases (PDP1, PDP2), pyruvate dehydrogenase kinases (PDK 1-4), and mitochondrial pyruvate carriers (MPC1, MPC2). As NADH-dependent oxidative phosphorylation is diminished in systolic heart failure, we tested whether the left ventricular myocardium (LV) from end-stage systolic adult heart failure patients (n = 26) exhibits altered expression of PDH complex subunits, PDK, MPC, PDP, and PDH complex activity, compared to LV from nonfailing donor hearts (n = 21). Compared to nonfailing LV, PDH activity and relative expression levels of E2, E3bp, E1α, and E1β subunits were greater in LV failure. PDK4, MPC1, and MPC2 expressions were decreased in failing LV, whereas PDP1, PDP2, PDK1, and PDK2 expressions did not differ between nonfailing and failing LV. In order to examine PDK4 further, donor human LV cardiomyocytes were induced in culture to hypertrophy with 0.1 μM angiotensin II and treated with PDK inhibitors (0.2 mM dichloroacetate, or 5 mM pyruvate) or activators (0.6 mM NADH plus 50 μM acetyl CoA). In isolated hypertrophic cardiomyocytes in vitro, PDK activators and inhibitors increased and decreased PDK4, respectively. In conclusion, in end-stage failing hearts, greater expression of PDH proteins and decreased expression of PDK4, MPC1, and MPC2 were evident with higher rates of PDH activity. These adaptations support sustained capacity for PDH to facilitate glucose metabolism in the face of other failing bioenergetic pathways.
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18
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Kulkarni PP, Tiwari A, Singh N, Gautam D, Sonkar VK, Agarwal V, Dash D. Aerobic glycolysis fuels platelet activation: small-molecule modulators of platelet metabolism as anti-thrombotic agents. Haematologica 2018; 104:806-818. [PMID: 30381300 PMCID: PMC6442984 DOI: 10.3324/haematol.2018.205724] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 10/30/2018] [Indexed: 12/14/2022] Open
Abstract
Platelets are critical to arterial thrombosis, which underlies myocardial infarction and stroke. Activated platelets, regardless of the nature of their stimulus, initiate energy-intensive processes that sustain thrombus, while adapting to potential adversities of hypoxia and nutrient deprivation within the densely packed thrombotic milieu. We report here that stimulated platelets switch their energy metabolism to aerobic glycolysis by modulating enzymes at key checkpoints in glucose metabolism. We found that aerobic glycolysis, in turn, accelerates flux through the pentose phosphate pathway and supports platelet activation. Hence, reversing metabolic adaptations of platelets could be an effective alternative to conventional anti-platelet approaches, which are crippled by remarkable redundancy in platelet agonists and ensuing signaling pathways. In support of this hypothesis, small-molecule modulators of pyruvate dehydrogenase, pyruvate kinase M2 and glucose-6-phosphate dehydrogenase, all of which impede aerobic glycolysis and/or the pentose phosphate pathway, restrained the agonist-induced platelet responses ex vivo. These drugs, which include the anti-neoplastic candidate, dichloroacetate, and the Food and Drug Administration-approved dehydroepiandrosterone, profoundly impaired thrombosis in mice, thereby exhibiting potential as anti-thrombotic agents.
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Affiliation(s)
| | | | - Nitesh Singh
- Department of Biochemistry, Institute of Medical Sciences
| | - Deepa Gautam
- Department of Biochemistry, Institute of Medical Sciences
| | - Vijay K Sonkar
- Department of Biochemistry, Institute of Medical Sciences
| | - Vikas Agarwal
- Department of Cardiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Debabrata Dash
- Department of Biochemistry, Institute of Medical Sciences
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19
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Karwi QG, Uddin GM, Ho KL, Lopaschuk GD. Loss of Metabolic Flexibility in the Failing Heart. Front Cardiovasc Med 2018; 5:68. [PMID: 29928647 PMCID: PMC5997788 DOI: 10.3389/fcvm.2018.00068] [Citation(s) in RCA: 248] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/18/2018] [Indexed: 12/15/2022] Open
Abstract
To maintain its high energy demand the heart is equipped with a highly complex and efficient enzymatic machinery that orchestrates ATP production using multiple energy substrates, namely fatty acids, carbohydrates (glucose and lactate), ketones and amino acids. The contribution of these individual substrates to ATP production can dramatically change, depending on such variables as substrate availability, hormonal status and energy demand. This "metabolic flexibility" is a remarkable virtue of the heart, which allows utilization of different energy substrates at different rates to maintain contractile function. In heart failure, cardiac function is reduced, which is accompanied by discernible energy metabolism perturbations and impaired metabolic flexibility. While it is generally agreed that overall mitochondrial ATP production is impaired in the failing heart, there is less consensus as to what actual switches in energy substrate preference occur. The failing heart shift toward a greater reliance on glycolysis and ketone body oxidation as a source of energy, with a decrease in the contribution of glucose oxidation to mitochondrial oxidative metabolism. The heart also becomes insulin resistant. However, there is less consensus as to what happens to fatty acid oxidation in heart failure. While it is generally believed that fatty acid oxidation decreases, a number of clinical and experimental studies suggest that fatty acid oxidation is either not changed or is increased in heart failure. Of importance, is that any metabolic shift that does occur has the potential to aggravate cardiac dysfunction and the progression of the heart failure. An increasing body of evidence shows that increasing cardiac ATP production and/or modulating cardiac energy substrate preference positively correlates with heart function and can lead to better outcomes. This includes increasing glucose and ketone oxidation and decreasing fatty acid oxidation. In this review we present the physiology of the energy metabolism pathways in the heart and the changes that occur in these pathways in heart failure. We also look at the interventions which are aimed at manipulating the myocardial metabolic pathways toward more efficient substrate utilization which will eventually improve cardiac performance.
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Affiliation(s)
| | | | | | - Gary D. Lopaschuk
- Cardiovascular Research Centre, University of Alberta, Edmonton, AB, Canada
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20
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Metabolic Modulators in Heart Disease: Past, Present, and Future. Can J Cardiol 2016; 33:838-849. [PMID: 28279520 DOI: 10.1016/j.cjca.2016.12.013] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 12/29/2022] Open
Abstract
Ischemic heart disease and heart failure are leading causes of mortality and morbidity worldwide. They continue to be major burden on health care systems throughout the world, despite major advances made over the past 40 years in developing new therapeutic approaches to treat these debilitating diseases. A potential therapeutic approach that has been underutilized in treating ischemic heart disease and heart failure is "metabolic modulation." Major alterations in myocardial energy substrate metabolism occur in ischemic heart disease and heart failure, and are associated with an energy deficit in the heart. A metabolic shift from mitochondrial oxidative metabolism to glycolysis, as well as an uncoupling between glycolysis and glucose oxidation, plays a crucial role in the development of cardiac inefficiency (oxygen consumed per work performed) and functional impairment in ischemic heart disease as well as in heart failure. This has led to the concept that optimizing energy substrate use with metabolic modulators can be a potentially promising approach to decrease the severity of ischemic heart disease and heart failure, primarily by improving cardiac efficiency. Two approaches for metabolic modulator therapy are to stimulate myocardial glucose oxidation and/or inhibit fatty acid oxidation. In this review, the past, present, and future of metabolic modulators as an approach to optimizing myocardial energy substrate metabolism and treating ischemic heart disease and heart failure are discussed. This includes a discussion of pharmacological interventions that target enzymes involved in fatty acid uptake, fatty acid oxidation, and glucose oxidation in the heart, as well as enzymes involved in ketone and branched chain amino acid catabolism in the heart.
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21
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Abstract
INTRODUCTION Angina pectoris, or symptomatic myocardial ischaemia, reflects an impairment of coronary blood flow, and usually a deficiency of available myocardial energetics. Treatment options vary with the precise cause, which may vary with regards to the roles of increased myocardial oxygen demand versus reduced supply. Traditionally, organic nitrates, β-adrenoceptor antagonists, and non-dihydropyridine calcium antagonists were the only commonly used prophylactic anti-anginal agents. However, many patients failed to respond adequately to such therapy, and/or were unsuitable for their use. Areas covered: A number of 'new' agents have been shown to represent ancillary forms of prophylactic anti-anginal therapy and are particularly useful in patients who are relatively unsuitable for either percutaneous or surgical revascularisation. These include modulators of myocardial metabolic efficiency, such as perhexiline, trimetazidine and ranolazine, as well as high dose allopurinol, nicorandil and ivabradine. The advantages and disadvantages of these various agents are summarized. Expert opinion: 'Optimal' medical treatment of angina pectoris now includes use of agents primarily intended to reduce risk of infarction (e.g. statins, aspirin, ACE inhibitors). In patients whose angina persists despite the use of 'standard' anti-anginal therapy, and who are not ideal for invasive revascularization options, a number of emerging drugs offer prospects of symptomatic relief.
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Affiliation(s)
- Cher-Rin Chong
- a Cardiology and Clinical Pharmacology Departments, Basil Hetzel Institute , Queen Elizabeth Hospital, University of Adelaide , Adelaide , SA , Australia.,b Pharmacy Department , Queen Elizabeth Hospital , Woodville South , SA , Australia
| | - Gao J Ong
- a Cardiology and Clinical Pharmacology Departments, Basil Hetzel Institute , Queen Elizabeth Hospital, University of Adelaide , Adelaide , SA , Australia
| | - John D Horowitz
- a Cardiology and Clinical Pharmacology Departments, Basil Hetzel Institute , Queen Elizabeth Hospital, University of Adelaide , Adelaide , SA , Australia
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22
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Abstract
Many patients with ischemic heart disease continue to experience anginal symptoms despite revascularization and treatment with antianginal medications. The effectiveness of current anti-ischemic medications is limited by their hemodynamic side effects, such as hypotension and bradycardia, which result in compromised organ perfusion. In this article, we review five novel agents (ranolazine, trimetazidine, L-carnitine, ribose, and dichloroacetate) under investigation for treatment of ischemic heart disease that work by enhancing the efficiency of the myocardium, rather than decreasing its work. This new paradigm promises to eliminate these side effects.
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Affiliation(s)
- Pirouz Parang
- Department of Medicine, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
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23
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Murphy E, Ardehali H, Balaban RS, DiLisa F, Dorn GW, Kitsis RN, Otsu K, Ping P, Rizzuto R, Sack MN, Wallace D, Youle RJ. Mitochondrial Function, Biology, and Role in Disease: A Scientific Statement From the American Heart Association. Circ Res 2016; 118:1960-91. [PMID: 27126807 PMCID: PMC6398603 DOI: 10.1161/res.0000000000000104] [Citation(s) in RCA: 303] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cardiovascular disease is a major leading cause of morbidity and mortality in the United States and elsewhere. Alterations in mitochondrial function are increasingly being recognized as a contributing factor in myocardial infarction and in patients presenting with cardiomyopathy. Recent understanding of the complex interaction of the mitochondria in regulating metabolism and cell death can provide novel insight and therapeutic targets. The purpose of this statement is to better define the potential role of mitochondria in the genesis of cardiovascular disease such as ischemia and heart failure. To accomplish this, we will define the key mitochondrial processes that play a role in cardiovascular disease that are potential targets for novel therapeutic interventions. This is an exciting time in mitochondrial research. The past decade has provided novel insight into the role of mitochondria function and their importance in complex diseases. This statement will define the key roles that mitochondria play in cardiovascular physiology and disease and provide insight into how mitochondrial defects can contribute to cardiovascular disease; it will also discuss potential biomarkers of mitochondrial disease and suggest potential novel therapeutic approaches.
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Taegtmeyer H, Young ME, Lopaschuk GD, Abel ED, Brunengraber H, Darley-Usmar V, Des Rosiers C, Gerszten R, Glatz JF, Griffin JL, Gropler RJ, Holzhuetter HG, Kizer JR, Lewandowski ED, Malloy CR, Neubauer S, Peterson LR, Portman MA, Recchia FA, Van Eyk JE, Wang TJ. Assessing Cardiac Metabolism: A Scientific Statement From the American Heart Association. Circ Res 2016; 118:1659-701. [PMID: 27012580 DOI: 10.1161/res.0000000000000097] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In a complex system of interrelated reactions, the heart converts chemical energy to mechanical energy. Energy transfer is achieved through coordinated activation of enzymes, ion channels, and contractile elements, as well as structural and membrane proteins. The heart's needs for energy are difficult to overestimate. At a time when the cardiovascular research community is discovering a plethora of new molecular methods to assess cardiac metabolism, the methods remain scattered in the literature. The present statement on "Assessing Cardiac Metabolism" seeks to provide a collective and curated resource on methods and models used to investigate established and emerging aspects of cardiac metabolism. Some of those methods are refinements of classic biochemical tools, whereas most others are recent additions from the powerful tools of molecular biology. The aim of this statement is to be useful to many and to do justice to a dynamic field of great complexity.
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25
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Davogustto G, Taegtmeyer H. The changing landscape of cardiac metabolism. J Mol Cell Cardiol 2015; 84:129-32. [PMID: 25937535 DOI: 10.1016/j.yjmcc.2015.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/26/2015] [Accepted: 04/27/2015] [Indexed: 02/07/2023]
Affiliation(s)
- Giovanni Davogustto
- Division of Cardiology, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA.
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26
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Matsuhashi T, Hishiki T, Zhou H, Ono T, Kaneda R, Iso T, Yamaguchi A, Endo J, Katsumata Y, Atsushi A, Yamamoto T, Shirakawa K, Yan X, Shinmura K, Suematsu M, Fukuda K, Sano M. Activation of pyruvate dehydrogenase by dichloroacetate has the potential to induce epigenetic remodeling in the heart. J Mol Cell Cardiol 2015; 82:116-24. [PMID: 25744081 DOI: 10.1016/j.yjmcc.2015.02.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 02/02/2015] [Accepted: 02/23/2015] [Indexed: 12/16/2022]
Abstract
Dichloroacetate (DCA) promotes pyruvate entry into the Krebs cycle by inhibiting pyruvate dehydrogenase (PDH) kinase and thereby maintaining PDH in the active dephosphorylated state. DCA has recently gained attention as a potential metabolic-targeting therapy for heart failure but the molecular basis of the therapeutic effect of DCA in the heart remains a mystery. Once-daily oral administration of DCA alleviates pressure overload-induced left ventricular remodeling. We examined changes in the metabolic fate of pyruvate carbon (derived from glucose) entering the Krebs cycle by metabolic interventions of DCA. (13)C6-glucose pathway tracing analysis revealed that instead of being completely oxidized in the mitochondria for ATP production, DCA-mediated PDH dephosphorylation results in an increased acetyl-CoA pool both in control and pressure-overloaded hearts. DCA induces hyperacetylation of histone H3K9 and H4 in a dose-dependent manner in parallel to the dephosphorylation of PDH in cultured cardiomyocytes. DCA administration increases histone H3K9 acetylation in in vivo mouse heart. Interestingly, DCA-dependent histone acetylation was associated with an up-regulation of 2.3% of genes (545 out of 23,474 examined). Gene ontology analysis revealed that these genes are highly enriched in transcription-related categories. This evidence suggests that sustained activation of PDH by DCA results in an overproduction of acetyl-CoA, which exceeds oxidation in the Krebs cycle and results in histone acetylation. We propose that DCA-mediated PDH activation has the potential to induce epigenetic remodeling in the heart, which, at least in part, forms the molecular basis for the therapeutic effect of DCA in the heart.
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Affiliation(s)
| | - Takako Hishiki
- Department of Biochemistry, Keio University, School of Medicine, Tokyo, Japan; Japan Science and Technology Agency, Exploratory Research for Advanced Technology, Suematsu Gas Biology Project, Tokyo, Japan
| | - Heping Zhou
- Department of Cardiovascular Surgery, First affiliated Hospital, Fourth Military Medical University, Xi'an, China
| | - Tomohiko Ono
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Ruri Kaneda
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Tokyo, Japan
| | - Tatsuya Iso
- Department of Medicine and Biological Science, Gunma University, Graduate School of Medicine, Gunma, Japan; Education and Research Support Center, Gunma University, Graduate School of Medicine, Gunma, Japan
| | - Aiko Yamaguchi
- Department of Bioimaging Information Analysis, Gunma University, Graduate School of Medicine, Gunma, Japan
| | - Jin Endo
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | | | - Anzai Atsushi
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Tsunehisa Yamamoto
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Kohsuke Shirakawa
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Xiaoxiang Yan
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Ken Shinmura
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University, School of Medicine, Tokyo, Japan; Japan Science and Technology Agency, Exploratory Research for Advanced Technology, Suematsu Gas Biology Project, Tokyo, Japan
| | - Keiichi Fukuda
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan
| | - Motoaki Sano
- Department of Cardiology, Keio University, School of Medicine, Tokyo, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Tokyo, Japan.
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Wang W, Lopaschuk GD. Metabolic therapy for the treatment of ischemic heart disease: reality and expectations. Expert Rev Cardiovasc Ther 2014; 5:1123-34. [DOI: 10.1586/14779072.5.6.1123] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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28
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Kolwicz SC, Purohit S, Tian R. Cardiac metabolism and its interactions with contraction, growth, and survival of cardiomyocytes. Circ Res 2013; 113:603-16. [PMID: 23948585 DOI: 10.1161/circresaha.113.302095] [Citation(s) in RCA: 532] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The network for cardiac fuel metabolism contains intricate sets of interacting pathways that result in both ATP-producing and non-ATP-producing end points for each class of energy substrates. The most salient feature of the network is the metabolic flexibility demonstrated in response to various stimuli, including developmental changes and nutritional status. The heart is also capable of remodeling the metabolic pathways in chronic pathophysiological conditions, which results in modulations of myocardial energetics and contractile function. In a quest to understand the complexity of the cardiac metabolic network, pharmacological and genetic tools have been engaged to manipulate cardiac metabolism in a variety of research models. In concert, a host of therapeutic interventions have been tested clinically to target substrate preference, insulin sensitivity, and mitochondrial function. In addition, the contribution of cellular metabolism to growth, survival, and other signaling pathways through the production of metabolic intermediates has been increasingly noted. In this review, we provide an overview of the cardiac metabolic network and highlight alterations observed in cardiac pathologies as well as strategies used as metabolic therapies in heart failure. Lastly, the ability of metabolic derivatives to intersect growth and survival are also discussed.
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Affiliation(s)
- Stephen C Kolwicz
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington School of Medicine, Seattle, WA 98109, USA
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Bayeva M, Sawicki KT, Ardehali H. Taking diabetes to heart--deregulation of myocardial lipid metabolism in diabetic cardiomyopathy. J Am Heart Assoc 2013; 2:e000433. [PMID: 24275630 PMCID: PMC3886738 DOI: 10.1161/jaha.113.000433] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marina Bayeva
- Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL
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30
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Stacpoole PW, Nagaraja NV, Hutson AD. Efficacy of Dichloroacetate as a Lactate-Lowering Drug. J Clin Pharmacol 2013. [DOI: 10.1177/0091270003254637] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Kalra BS, Roy V. Efficacy of Metabolic Modulators in Ischemic Heart Disease: An Overview. J Clin Pharmacol 2013; 52:292-305. [DOI: 10.1177/0091270010396042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Ardehali H, Sabbah HN, Burke MA, Sarma S, Liu PP, Cleland JGF, Maggioni A, Fonarow GC, Abel ED, Campia U, Gheorghiade M. Targeting myocardial substrate metabolism in heart failure: potential for new therapies. Eur J Heart Fail 2012; 14:120-9. [PMID: 22253453 DOI: 10.1093/eurjhf/hfr173] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The incidence and prevalence of heart failure have increased significantly over the past few decades. Available data suggest that patients with heart failure independent of the aetiology have viable but dysfunctional myocardium that is potentially salvageable. Although a great deal of research effort has focused on characterizing the molecular basis of heart failure, cardiac metabolism in this disorder remains an understudied discipline. It is known that many aspects of cardiomyocyte energetics are altered in heart failure. These include a shift from fatty acid to glucose as a preferred substrate and a decline in the levels of ATP. Despite these demonstrated changes, there are currently no approved drugs that target metabolic enzymes or proteins in heart failure. This is partly due to our limited knowledge of the mechanisms and pathways that regulate cardiac metabolism. Better characterization of these pathways may potentially lead to new therapies for heart failure. Targeting myocardial energetics in the viable and potentially salvageable tissue may be particularly effective in the treatment of heart failure. Here, we will review metabolic changes that occur in fatty acid and glucose metabolism and AMP-activated kinase in heart failure. We propose that cardiac energetics should be considered as a potential target for therapy in heart failure and more research should be done in this area.
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Affiliation(s)
- Hossein Ardehali
- Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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Vella S, Conti M, Tasso R, Cancedda R, Pagano A. Dichloroacetate inhibits neuroblastoma growth by specifically acting against malignant undifferentiated cells. Int J Cancer 2011; 130:1484-93. [PMID: 21557214 DOI: 10.1002/ijc.26173] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 04/20/2011] [Indexed: 12/13/2022]
Abstract
The small, water soluble molecule Dichloroacetate (DCA) is recently arousing lively interests in the field of cancer therapy for it has been shown to be able to inhibit the growth of human tumors acting specifically on the mitochondria of cancer cells without perturbing the physiology of nonmalignant cells. Neuroblastoma was one of the tumor types on which DCA was considered ineffective as it is composed of cells with few recognized mitochondrial anomalies. Neuroblastoma, however, is composed of different cell types in terms of metabolism, phenotype and malignant potential. Despite the above prediction, in this work, we show that (i) DCA exhibits an unexpected anticancer effect on NB tumor cells and (ii) this effect is selectively directed to very malignant NB cells, whereas the more differentiated/less malignant NB cells are refractory to DCA treatment. This result supports the need of a detailed investigation of DCA anticancer properties against this tumor type with the final aim of its possible use as therapeutic agent.
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Affiliation(s)
- Serena Vella
- Oncology, Biology, and Genetics Department (DOBiG), University of Genoa, Genoa-Italy
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34
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Jaswal JS, Keung W, Wang W, Ussher JR, Lopaschuk GD. Targeting fatty acid and carbohydrate oxidation--a novel therapeutic intervention in the ischemic and failing heart. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1333-50. [PMID: 21256164 DOI: 10.1016/j.bbamcr.2011.01.015] [Citation(s) in RCA: 266] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 12/16/2010] [Accepted: 01/11/2011] [Indexed: 12/19/2022]
Abstract
Cardiac ischemia and its consequences including heart failure, which itself has emerged as the leading cause of morbidity and mortality in developed countries are accompanied by complex alterations in myocardial energy substrate metabolism. In contrast to the normal heart, where fatty acid and glucose metabolism are tightly regulated, the dynamic relationship between fatty acid β-oxidation and glucose oxidation is perturbed in ischemic and ischemic-reperfused hearts, as well as in the failing heart. These metabolic alterations negatively impact both cardiac efficiency and function. Specifically there is an increased reliance on glycolysis during ischemia and fatty acid β-oxidation during reperfusion following ischemia as sources of adenosine triphosphate (ATP) production. Depending on the severity of heart failure, the contribution of overall myocardial oxidative metabolism (fatty acid β-oxidation and glucose oxidation) to adenosine triphosphate production can be depressed, while that of glycolysis can be increased. Nonetheless, the balance between fatty acid β-oxidation and glucose oxidation is amenable to pharmacological intervention at multiple levels of each metabolic pathway. This review will focus on the pathways of cardiac fatty acid and glucose metabolism, and the metabolic phenotypes of ischemic and ischemic/reperfused hearts, as well as the metabolic phenotype of the failing heart. Furthermore, as energy substrate metabolism has emerged as a novel therapeutic intervention in these cardiac pathologies, this review will describe the mechanistic bases and rationale for the use of pharmacological agents that modify energy substrate metabolism to improve cardiac function in the ischemic and failing heart. This article is part of a Special Issue entitled: Mitochondria and Cardioprotection.
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Affiliation(s)
- Jagdip S Jaswal
- Mazankowski Alberta Heart Institute, Departments of Pediatrics and Pharmacology, University of Alberta, Edmonton, Alberta, Canada
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Papandreou I, Goliasova T, Denko NC. Anticancer drugs that target metabolism: Is dichloroacetate the new paradigm? Int J Cancer 2010; 128:1001-8. [PMID: 20957634 DOI: 10.1002/ijc.25728] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 09/30/2010] [Indexed: 11/08/2022]
Abstract
Recent findings in the fields of oncogenic regulation of metabolism, mitochondrial function and macromolecular synthesis have brought tumor metabolism and the Warburg effect back into the scientific limelight. A number of metabolic pathways that seem to be important for tumor growth are being touted as novel targets for anticancer drug development. One of the candidates in this class of drugs being investigated is dichloroacetate (DCA), a molecule used for over 25 years in the treatment of children with inborn errors in mitochondrial function. This pyruvate mimetic compound stimulates mitochondrial function by inhibiting the family of regulatory pyruvate dehydrogenase kinases (PDK1-4). The stimulation of mitochondrial function, at the expense of glycolysis, reverses the Warburg effect and is thought to block the growth advantage of highly glycolytic tumors. Interestingly, some of the recent in vitro findings have shown very modest "antitumor cell activity" of DCA when cells are treated in a dish. However, several studies have reported "antitumor activity" in model tumors. This apparent paradox raises the question, how do we evaluate cancer drugs designed to target tumor metabolism? Traditional approaches in cancer drug development have used in vitro assays as a first pass to evaluate potential lead compounds. The fact that DCA has better in vivo activity than in vitro activity suggests that there are unique aspects of solid tumor growth and metabolism that are difficult to recapitulate in vitro and may be important in determining the effectiveness of this class of drugs.
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Affiliation(s)
- Ioanna Papandreou
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, Stanford University School of Medicine, Stanford, CA, USA
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Nie J, DuBois DC, Jusko WJ, Almon RR. Mechanistic population modeling of diabetes disease progression in Goto-Kakizaki rat muscle. Biopharm Drug Dispos 2010; 32:50-63. [PMID: 21162119 DOI: 10.1002/bdd.738] [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: 04/21/2010] [Revised: 11/04/2010] [Accepted: 11/05/2010] [Indexed: 12/31/2022]
Abstract
Pyruvate dehydrogenase kinase 4 (PDK4) is a lipid status responsive gene involved in muscle fuel selection. Evidence is mounting in support of the therapeutic potential of PDK4 inhibitors to treat diabetes. Factors that regulate PDK4 mRNA expression include plasma corticosterone, insulin and free fatty acids. The objective was to determine the impact of those plasma factors on PDK4 mRNA and to develop and validate a population mathematical model to differentiate aging, diet and disease effects on muscle PDK4 expression. The Goto-Kakizaki (GK) rat, a polygenic non-obese model of type 2 diabetes, was used as the diabetic animal model. Muscle PDK4 mRNA expression was examined by real-time QRTPCR. Groups of GK rats along with controls fed with either a normal or high fat diet were killed at 4, 8, 12, 16 and 20 weeks of age. Plasma corticosterone, insulin and free fatty acids were measured. The proposed mechanism-based model successfully described the age, disease and diet effects and the relative contribution of these plasma regulators on PDK4 mRNA expression. Muscle growth reduced the PDK4 mRNA production rate by 14% per gram increase. The high fat diet increased the initial production rate constant in GK rats by 2.19-fold. The model indicated that corticosterone had a moderate effect and PDK4 was more sensitive to free fatty acid than insulin fluxes, which was in good agreement with the literature data.
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Affiliation(s)
- Jing Nie
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY 14260, USA
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37
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Lopaschuk GD, Ussher JR, Folmes CDL, Jaswal JS, Stanley WC. Myocardial fatty acid metabolism in health and disease. Physiol Rev 2010; 90:207-58. [PMID: 20086077 DOI: 10.1152/physrev.00015.2009] [Citation(s) in RCA: 1459] [Impact Index Per Article: 104.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
There is a constant high demand for energy to sustain the continuous contractile activity of the heart, which is met primarily by the beta-oxidation of long-chain fatty acids. The control of fatty acid beta-oxidation is complex and is aimed at ensuring that the supply and oxidation of the fatty acids is sufficient to meet the energy demands of the heart. The metabolism of fatty acids via beta-oxidation is not regulated in isolation; rather, it occurs in response to alterations in contractile work, the presence of competing substrates (i.e., glucose, lactate, ketones, amino acids), changes in hormonal milieu, and limitations in oxygen supply. Alterations in fatty acid metabolism can contribute to cardiac pathology. For instance, the excessive uptake and beta-oxidation of fatty acids in obesity and diabetes can compromise cardiac function. Furthermore, alterations in fatty acid beta-oxidation both during and after ischemia and in the failing heart can also contribute to cardiac pathology. This paper reviews the regulation of myocardial fatty acid beta-oxidation and how alterations in fatty acid beta-oxidation can contribute to heart disease. The implications of inhibiting fatty acid beta-oxidation as a potential novel therapeutic approach for the treatment of various forms of heart disease are also discussed.
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Affiliation(s)
- Gary D Lopaschuk
- Cardiovascular Research Group, Mazankowski Alberta Heart Institute, University of Alberta, Alberta T6G 2S2, Canada.
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38
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Jaswal JS, Ussher JR, Lopaschuk GD. Myocardial fatty acid utilization as a determinant of cardiac efficiency and function. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.18] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Lewis JF, DaCosta M, Wargowich T, Stacpoole P. Effects of dichloroacetate in patients with congestive heart failure. Clin Cardiol 2009; 21:888-92. [PMID: 9853180 PMCID: PMC6656110 DOI: 10.1002/clc.4960211206] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Conventional approaches to management of congestive heart failure (CHF) rely on drugs that increase myocardial contractility or reduce ventricular afterload. These approaches often improve cardiac symptoms and survival, but may be associated with significant deleterious effects. An alternative approach is to enhance myocardial energy production. Dichloroacetate (DCA) stimulates pyruvate dehydrogenase activity and accelerates aerobic glucose, pyruvate, and lactate metabolism in myocardial cells. These alterations would be expected to improve myocardial function. HYPOTHESIS The purpose of the investigation was to assess the efficacy of DCA in patients with left ventricular systolic dysfunction and to examine the mechanism by which improvement occurs. METHODS A total of 25 patients (16 men, 9 women; age range 31-72 years, mean 59) with CHF and ejection fraction < or = 40% received an intravenous infusion of 50 mg/kg DCA over 15 min. Indices of systolic and diastolic function were obtained by two-dimensional and Doppler echocardiography performed at baseline, 30 min, and 60 min following completion of DCA infusion. RESULTS Baseline ventricular ejection fraction was 27.3 +/- 9.1%; 17 patients (68%) had nonischemic cardiomyopathy. Heart rate increased after DCA infusion from 73.9 +/- 14.5 to 79.2 +/- 14.9 beats/min at 60 min; p = 0.02. Left ventricular diastolic and systolic volumes increased at 30 min compared with baseline (248.7 +/- 98.1 vs. 259.6 +/- 99.6; p = 0.04, and 180.1 +/- 80.4 vs. 192.2 +/- 84.9; p = 0.002, respectively), but stroke volume (49.2 +/- 19.1 vs. 48.9 +/- 18.1; p = 0.9) and ejection fraction (27.3 +/- 9.1 vs. 25.7 +/- 9.8; p = 0.2) were unchanged. Indices of diastolic function were also unchanged. CONCLUSION Dichloroacetate infusion in patients with CHF is not associated with improvement in noninvasively assessed left ventricular function.
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Affiliation(s)
- J F Lewis
- Department of Medicine, University of Florida College of Medicine, Gainesville, USA
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Rhodes CJ, Davidson A, Gibbs JSR, Wharton J, Wilkins MR. Therapeutic targets in pulmonary arterial hypertension. Pharmacol Ther 2008; 121:69-88. [PMID: 19010350 DOI: 10.1016/j.pharmthera.2008.10.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 10/07/2008] [Indexed: 01/02/2023]
Abstract
Pulmonary arterial hypertension is a progressive, fatal disease. Current treatments including prostanoids, endothelin-1 (ET-1) antagonists, and phosphodiesterase (PDE) inhibitors, have sought to address the pulmonary vascular endothelial dysfunction and vasoconstriction associated with the condition. These treatments may slow the progression of the disease but do not afford a cure. Future treatments must target more directly the structural vascular changes that impair blood flow through the pulmonary circulation. Several novel therapeutic targets have been proposed and are under active investigation, including soluble guanylyl cyclase, phosphodiesterases, tetrahydrobiopterin, 5-HT2B receptors, vasoactive intestinal peptide, receptor tyrosine kinases, adrenomedullin, Rho kinase, elastases, endogenous steroids, endothelial progenitor cells, immune cells, bone morphogenetic protein and its receptors, potassium channels, metabolic pathways, and nuclear factor of activated T cells. Tyrosine kinase inhibitors, statins, 5-HT2B receptor antagonists, EPCs and soluble guanylyl cyclase activators are among the most advanced, having produced encouraging results in animal models, and human trials are underway. This review summarises the current research in this area and speculates on their likely success.
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Affiliation(s)
- Christopher J Rhodes
- Department of Experimental Medicine and Toxicology, Imperial College London, and National Pulmonary Hypertension Service, Hammersmith Hospital, United Kingdom
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41
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Henderson GN, Whalen PO, Darr RA, Curry SH, Derendorf H, Baumgartner TG, Stacpoole PW. Development of an Oral Drug Formulation for Dichloroacetate and Thiamine. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049409042647] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nagendran J, Gurtu V, Fu DZ, Dyck JRB, Haromy A, Ross DB, Rebeyka IM, Michelakis ED. A dynamic and chamber-specific mitochondrial remodeling in right ventricular hypertrophy can be therapeutically targeted. J Thorac Cardiovasc Surg 2008; 136:168-78, 178.e1-3. [PMID: 18603070 DOI: 10.1016/j.jtcvs.2008.01.040] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 12/04/2007] [Accepted: 01/29/2008] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The right ventricle fails quickly after increases in its afterload (ie, pulmonary hypertension) compared with the left ventricle (ie, systemic hypertension), resulting in significant morbidity and mortality. We hypothesized that the poor performance of the hypertrophied right ventricle is caused, at least in part, by a suboptimal mitochondrial/metabolic remodeling. METHODS/RESULTS We studied mitochondrial membrane potential, a surrogate for mitochondrial function, in human (n = 11) and rat hearts with physiologic (neonatal) and pathologic (pulmonary hypertension) right ventricular hypertrophy in vivo and in vitro. Mitochondrial membrane potential is higher in the normal left ventricle compared with the right ventricle but is highest in the hypertrophied right ventricle, both in myocardium and in isolated cardiomyocytes (P < .01). Mitochondrial membrane potential correlated positively with the degree of right ventricular hypertrophy in vivo and was recapitulated in phenylephrine-treated neonatal cardiomyocytes, an in vitro model of hypertrophy. The phenylephrine-induced mitochondrial hyperpolarization was reversed by VIVIT, an inhibitor of the nuclear factor of activated T lymphocytes, a transcription factor regulating the expression of several mitochondrial enzymes during cardiac development and hypertrophy. The clinically used drug dichloroacetate, known to increase the mitochondria-based glucose oxidation, reversed both the phenylephrine-induced mitochondrial hyperpolarization and nuclear factor of activated T lymphocytes (NFAT) activation. In Langendorff perfusions, dichloroacetate increased rat right ventricular inotropy in hypertrophied right ventricles (P < .01) but not in normal right ventricles, suggesting that mitochondrial hyperpolarization in right ventricular hypertrophy might be associated with its suboptimal performance. CONCLUSIONS The dynamic changes in mitochondrial membrane potential during right ventricular hypertrophy are chamber-specific, associated with activation of NFAT, and can be pharmacologically reversed leading to improved contractility. This mitochondrial remodeling might provide a framework for development of novel right ventricle-specific therapies.
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Affiliation(s)
- Jayan Nagendran
- Pulmonary Hypertension Program, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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Ussher JR, Lopaschuk GD. The malonyl CoA axis as a potential target for treating ischaemic heart disease. Cardiovasc Res 2008; 79:259-68. [PMID: 18499682 DOI: 10.1093/cvr/cvn130] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular disease is the leading cause of death and disability for people living in western societies, with ischaemic heart disease accounting for the majority of this health burden. The primary treatment for ischaemic heart disease consists of either improving blood and oxygen supply to the heart or reducing the heart's oxygen demand. Unfortunately, despite recent advances with these approaches, ischaemic heart disease still remains a major health problem. Therefore, the development of new treatment strategies is still required. One exciting new approach is to optimize cardiac energy metabolism, particularly by decreasing the use of fatty acids as a fuel and by increasing the use of glucose as a fuel. This approach is beneficial in the setting of ischaemic heart disease, as it allows the heart to produce energy more efficiently and it reduces the degree of acidosis associated with ischaemia/reperfusion. Malonyl CoA is a potent endogenous inhibitor of cardiac fatty acid oxidation, secondary to inhibiting carnitine palmitoyl transferase-I, the rate-limiting enzyme in the mitochondrial uptake of fatty acids. Malonyl CoA is synthesized in the heart by acetyl CoA carboxylase, which in turn is phosphorylated and inhibited by 5'AMP-activated protein kinase. The degradation of myocardial malonyl CoA occurs via malonyl CoA decarboxylase (MCD). Previous studies have shown that inhibiting MCD will significantly increase cardiac malonyl CoA levels. This is associated with an increase in glucose oxidation, a decrease in acidosis, and an improvement in cardiac function and efficiency during and following ischaemia. Hence, the malonyl CoA axis represents an exciting new target for the treatment of ischaemic heart disease.
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Affiliation(s)
- John R Ussher
- Cardiovascular Research Group, Department of Pediatrics, University of Alberta, Edmonton, Canada
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Hara A, Matsumura H, Maruyama K, Hashizume H, Ushikubi F, Abiko Y. Ranolazine:an Antiischemic Drug with a Novel Mechanism of Action. ACTA ACUST UNITED AC 2006. [DOI: 10.1111/j.1527-3466.1999.tb00004.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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45
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Solaini G, Harris D. Biochemical dysfunction in heart mitochondria exposed to ischaemia and reperfusion. Biochem J 2006; 390:377-94. [PMID: 16108756 PMCID: PMC1198918 DOI: 10.1042/bj20042006] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Heart tissue is remarkably sensitive to oxygen deprivation. Although heart cells, like those of most tissues, rapidly adapt to anoxic conditions, relatively short periods of ischaemia and subsequent reperfusion lead to extensive tissue death during cardiac infarction. Heart tissue is not readily regenerated, and permanent heart damage is the result. Although mitochondria maintain normal heart function by providing virtually all of the heart's ATP, they are also implicated in the development of ischaemic damage. While mitochondria do provide some mechanisms that protect against ischaemic damage (such as an endogenous inhibitor of the F1Fo-ATPase and antioxidant enzymes), they also possess a range of elements that exacerbate it, including ROS (reactive oxygen species) generators, the mitochondrial permeability transition pore, and their ability to release apoptotic factors. This review considers the process of ischaemic damage from a mitochondrial viewpoint. It considers ischaemic changes in the inner membrane complexes I-V, and how this might affect formation of ROS and high-energy phosphate production/degradation. We discuss the contribution of various mitochondrial cation channels to ionic imbalances which seem to be a major cause of reperfusion injury. The different roles of the H+, Ca2+ and the various K+ channel transporters are considered, particularly the K+(ATP) (ATP-dependent K+) channels. A possible role for the mitochondrial permeability transition pore in ischaemic damage is assessed. Finally, we summarize the metabolic and pharmacological interventions that have been used to alleviate the effects of ischaemic injury, highlighting the value of these or related interventions in possible therapeutics.
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Affiliation(s)
- Giancarlo Solaini
- *Scuola Superiore di Studi Universitari e di Perfezionamento S. Anna, Classe Accademica di Scienze Sperimentali, Piazza dei Martiri della Libertà 33, 56127 Pisa, Italy
| | - David A. Harris
- †Department of Biochemistry, University of Oxford, South Parks Rd., Oxford OX1 3QU, U.K
- To whom correspondence should be addressed (email )
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Folmes CDL, Clanachan AS, Lopaschuk GD. Fatty acid oxidation inhibitors in the management of chronic complications of atherosclerosis. Curr Atheroscler Rep 2005; 7:63-70. [PMID: 15683605 DOI: 10.1007/s11883-005-0077-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ischemic heart disease is characterized by a modification of the normal energy balance of the heart. During and following an ischemic event, circulating fatty acids are elevated, resulting in the acceleration of fatty acid oxidation at the expense of glucose oxidation. Despite the reduction in glucose oxidation, the rate of glycolysis increases, leading to an uncoupling of glucose metabolism. This results in the accumulation of metabolic byproducts, which leads to a decrease in cardiac efficiency. A novel therapeutic strategy involves improving the efficiency of oxygen utilization by the ischemic heart by the modulation of energy metabolism. This can be achieved by a reduction in the levels of circulating fatty acids using beta-blockers, glucose-insulin-potassium infusions, and nicotinic acid. Alternatively, fatty acid oxidation can be directly inhibited using trimetazidine, ranolazine, or glucose oxidation directly activated using dichloroacetate, which significantly improves the efficiency of the heart.
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Affiliation(s)
- Clifford D L Folmes
- Cardiovascular Research Group, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
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47
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Abstract
The number of patients with coronary artery disease and its risk factors is increasing in Western nations. New treatments for these patients may soon include a class of agents known as the metabolic modulators. This group of agents consists of the partial fatty acid oxidation inhibitors trimetazidine and ranolazine, as well as dichloroacetate, which promotes carbohydrate utilization. Metabolic modulators also include the nutriceuticals L-carnitine and D-ribose. The available evidence regarding the benefits of each of these five agents is reviewed.
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Affiliation(s)
- Daniel F Pauly
- University of Florida College of Medicine, Division of Cardiovascular Medicine, Gainesville, Florida 32610, USA.
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48
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L'Her E, Sebert P. Effects of dichloroacetate and ubiquinone infusions on glycolysis activity and thermal sensitivity during sepsis. ACTA ACUST UNITED AC 2004; 143:352-7. [PMID: 15192651 DOI: 10.1016/j.lab.2004.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Energy-metabolism disturbances during sepsis are characterized by enhanced glycolytic fluxes and reduced mitochondrial respiration. However, it is not known whether these abnormalities are the result of a specific mitochondrial alteration, decreased pyruvate dehydrogenase (PDH) complex activity, depletion of ubiquinone (CoQ(10); electron donor for the mitochondrial complex III), or all 3. In this study we sought to specify metabolism disturbances in a murine model of sepsis, using either a PDH-activator infusion (dichloroacetate, DCA) or CoQ(10) supplementation. After anesthesia, Sprague-Dawley rats received intravenous saline solution (control; n = 5), DCA (n = 5; 20 mg/100 g), or CoQ(10) (n = 5; 1 mg/100 g), before the induction of sepsis. Increased plasma lactate levels and increased muscle glucose content were observed after 4 hours in the control group. In the DCA group, a decrease in the muscle content of lactate (P <.05) and an increase in muscle glucose content (P <.05) were observed at 4 hours, but no lactatemia variation was noted. In the CoQ(10) group, only increased plasma lactate levels were observed. Increased muscle glycolysis fluxes were observed after 4 hours in the control group, but to a slighter degree in both the DCA and CoQ(10) groups. Only DCA restored a normal temperature sensitivity in the hyperthermia range, but we noted no differences in survival time. In conclusion, only DCA infusion restores normal glycolysis function.
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Affiliation(s)
- Erwan L'Her
- Reánimation et Urgences Médicales, Centre Hospitalier Universitaire de la Cavale Blanche, Brest, France.
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Wilson JS, Rushing G, Johnson BL, Kline JA, Back MR, Bandyk DF. Dichloroacetate increases skeletal muscle pyruvate dehydrogenase activity during acute limb ischemia. Vasc Endovascular Surg 2003; 37:191-5. [PMID: 12799728 DOI: 10.1177/153857440303700306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to evaluate the effects of dichloroacetate sodium (DCA), a drug that inactivates pyruvate dehydrogenase kinase (PDH-K), on pyruvate dehydrogenase (PDH) activity, lactate level, and function of skeletal muscle in an experimental model of acute limb ischemia. Thirty-two male Sprague-Dawley rats underwent right iliac artery ligation to produce hindlimb ischemia. After 2 hours of ischemia, 16 animals received intravenous DCA (15 mg/100 g body weight) and 16 control animals received an equivalent volume of normal saline. After an additional 1 hour of ischemia (total 3 hours) tibialis anterior muscle from the ischemic limb and contralateral nonischemic limb was excised, rapidly freeze-clamped with Wallenberg tongs cooled in liquid nitrogen, and stored at -70 degrees C. Muscles specimens were subsequently assayed for PDH activity and lactate level by use of spectrophotometric techniques. An additional 16 animals (DCA-treated, n = 8; control, n = 8) underwent ex-vivo gastrocnemius muscle fatigue testing with a 10 g tension preload after 3 hours of limb ischemia. In ischemic hind limbs, DCA treatment significantly (p = 0.025) increased PDH activity (19.6 +/-1.6 micromol/min/g dry weight) compared to controls (13.1 +/-1.3 micromol/min/g dry weight). DCA treatment did not increase (p = 0.13) skeletal muscle PDH activity in the nonischemic limbs (9.6 +/-1.1 micromol/min/g dry weight, controls; 13.2 +/-1.3 micromol/min/g dry weight, DCA group). In DCA-treated animals, hind limb ischemia resulted in no significant increase in muscle lactate levels compared to the nonischemic limb, while control animals demonstrated a significant (p = 0.005) elevation in lactate level in ischemic limbs compared to contralateral nonischemic limb. Ischemia induced a significant decrease in time to muscle fatigue in both DCA-treated and control animals (p = 0.002 and 0.001, respectively). Time to muscle fatigue in DCA-treated animals was increased compared to controls (2.6 +/-0.3 versus 2 +/-0.6 minutes; p < 0.05)in ischemic limbs but was not significantly different in nonischemic limbs (DCA = 3.3 +/-0.5 minutes; control = 3.1 +/-0.6 minutes). Treatment with DCA during acute limb ischemia reduced the depression of PDH activity and lactate level of skeletal muscle. Ischemic muscle function was also improved by DCA treatment. Further investigation of the potential beneficial effects of DCA treatment on muscle injury during ischemia and reperfusion is warranted.
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Affiliation(s)
- Jeffrey S Wilson
- Division of Vascular and Endovascular Surgery, University of South Florida College of Medicine, Tampa, FL, USA
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Sack MN, Yellon DM. Insulin therapy as an adjunct to reperfusion after acute coronary ischemia: a proposed direct myocardial cell survival effect independent of metabolic modulation. J Am Coll Cardiol 2003; 41:1404-7. [PMID: 12706939 DOI: 10.1016/s0735-1097(03)00164-5] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reperfusion therapy has become a practical and effective strategy in the salvage of ischemic myocardium. The direct enhancement of cardiac cellular tolerance against ischemic and reperfusion injury should further improve patient outcome in acute coronary syndromes (ACS). This approach has been explored for many decades, and although we await mortality-weighted randomized clinical trials, the infusion of glucose-insulin-potassium (GIK) has shown promise in protecting post-infarct myocardium. The current dogma is that this cardioprotective effect of GIK acts via the modulation of cardiac and circulating metabolites to provide the heart with an optimal metabolic milieu to resist ischemia and reperfusion injury. This concept of metabolic modulation has gained favor in coronary heart disease, and its efficacy currently is being investigated in stable angina using the new class of partial fatty acid oxidation inhibitors, including trimetazidine and ranolazine. We contend that the mitogen insulin, itself, promotes tolerance against ischemic cell death via the activation of innate cell-survival pathways in the heart. To advance this viewpoint, we will present clinical data that support a dose-dependent effect of insulin's beneficial action in the management of acute myocardial infarction. Furthermore, we present experimental data that identify cell-survival programs that are directly activated by the administration of insulin. Finally, as intravenous insulin therapy is both labor intensive and associated with metabolic perturbations, we propose that the development of pharmaco-therapeutic agents that target downstream cell-survival insulin-activated signaling molecules may be an alternate approach to promote cardioprotection during ACS.
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Affiliation(s)
- Michael N Sack
- The Hatter Institute for Cardiology Research, MRC Inter-University Cape Heart Group, University of Cape Town Medical School, South Africa
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