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Kankuri E, Finckenberg P, Leinonen J, Tarkia M, Björk S, Purhonen J, Kallijärvi J, Kankainen M, Soliymani R, Lalowski M, Mervaala E. Altered acylcarnitine metabolism and inflexible mitochondrial fuel utilization characterize the loss of neonatal myocardial regeneration capacity. Exp Mol Med 2023; 55:806-817. [PMID: 37009793 PMCID: PMC10167339 DOI: 10.1038/s12276-023-00967-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 11/29/2022] [Accepted: 12/23/2022] [Indexed: 04/04/2023] Open
Abstract
Myocardial regeneration capacity declines during the first week after birth, and this decline is linked to adaptation to oxidative metabolism. Utilizing this regenerative window, we characterized the metabolic changes in myocardial injury in 1-day-old regeneration-competent and 7-day-old regeneration-compromised mice. The mice were either sham-operated or received left anterior descending coronary artery ligation to induce myocardial infarction (MI) and acute ischemic heart failure. Myocardial samples were collected 21 days after operations for metabolomic, transcriptomic and proteomic analyses. Phenotypic characterizations were carried out using echocardiography, histology and mitochondrial structural and functional assessments. In both groups, MI induced an early decline in cardiac function that persisted in the regeneration-compromised mice over time. By integrating the findings from metabolomic, transcriptomic and proteomic examinations, we linked regeneration failure to the accumulation of long-chain acylcarnitines and insufficient metabolic capacity for fatty acid beta-oxidation. Decreased expression of the redox-sensitive mitochondrial Slc25a20 carnitine-acylcarnitine translocase together with a decreased reduced:oxidized glutathione ratio in the myocardium in the regeneration-compromised mice pointed to a defect in the redox-sensitive acylcarnitine transport to the mitochondrial matrix. Rather than a forced shift from the preferred adult myocardial oxidative fuel source, our results suggest the facilitation of mitochondrial fatty acid transport and improvement of the beta-oxidation pathway as a means to overcome the metabolic barrier for repair and regeneration in adult mammals after MI and heart failure.
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Affiliation(s)
- E Kankuri
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - P Finckenberg
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - J Leinonen
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - M Tarkia
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - S Björk
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - J Purhonen
- Folkhälsan Research Center, Helsinki, Finland
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - J Kallijärvi
- Folkhälsan Research Center, Helsinki, Finland
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - M Kankainen
- Medical and Clinical Genetics, Faculty of Medicine, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
- Translational Immunology Research Program and Department of Clinical Chemistry, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - R Soliymani
- Helsinki Institute of Life Science (HiLIFE), Meilahti Clinical Proteomics Core Facility, Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - M Lalowski
- Helsinki Institute of Life Science (HiLIFE), Meilahti Clinical Proteomics Core Facility, Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - E Mervaala
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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2
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Targeting mitochondrial impairment for the treatment of cardiovascular diseases: From hypertension to ischemia-reperfusion injury, searching for new pharmacological targets. Biochem Pharmacol 2023; 208:115405. [PMID: 36603686 DOI: 10.1016/j.bcp.2022.115405] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Mitochondria and mitochondrial proteins represent a group of promising pharmacological target candidates in the search of new molecular targets and drugs to counteract the onset of hypertension and more in general cardiovascular diseases (CVDs). Indeed, several mitochondrial pathways result impaired in CVDs, showing ATP depletion and ROS production as common traits of cardiac tissue degeneration. Thus, targeting mitochondrial dysfunction in cardiomyocytes can represent a successful strategy to prevent heart failure. In this context, the identification of new pharmacological targets among mitochondrial proteins paves the way for the design of new selective drugs. Thanks to the advances in omics approaches, to a greater availability of mitochondrial crystallized protein structures and to the development of new computational approaches for protein 3D-modelling and drug design, it is now possible to investigate in detail impaired mitochondrial pathways in CVDs. Furthermore, it is possible to design new powerful drugs able to hit the selected pharmacological targets in a highly selective way to rescue mitochondrial dysfunction and prevent cardiac tissue degeneration. The role of mitochondrial dysfunction in the onset of CVDs appears increasingly evident, as reflected by the impairment of proteins involved in lipid peroxidation, mitochondrial dynamics, respiratory chain complexes, and membrane polarization maintenance in CVD patients. Conversely, little is known about proteins responsible for the cross-talk between mitochondria and cytoplasm in cardiomyocytes. Mitochondrial transporters of the SLC25A family, in particular, are responsible for the translocation of nucleotides (e.g., ATP), amino acids (e.g., aspartate, glutamate, ornithine), organic acids (e.g. malate and 2-oxoglutarate), and other cofactors (e.g., inorganic phosphate, NAD+, FAD, carnitine, CoA derivatives) between the mitochondrial and cytosolic compartments. Thus, mitochondrial transporters play a key role in the mitochondria-cytosol cross-talk by leading metabolic pathways such as the malate/aspartate shuttle, the carnitine shuttle, the ATP export from mitochondria, and the regulation of permeability transition pore opening. Since all these pathways are crucial for maintaining healthy cardiomyocytes, mitochondrial carriers emerge as an interesting class of new possible pharmacological targets for CVD treatments.
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3
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Surendran A, Atefi N, Ismail U, Shah A, Ravandi A. Impact of myocardial reperfusion on human plasma lipidome. iScience 2022; 25:103828. [PMID: 35198888 PMCID: PMC8850755 DOI: 10.1016/j.isci.2022.103828] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/20/2021] [Accepted: 01/21/2022] [Indexed: 11/16/2022] Open
Abstract
The primary aim of the study is to investigate the temporal changes in plasma lipidome before and after reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) and their association with myocardial injury. We found that 56% of the identified lipid species were significantly altered (corrected p< 0.05) in the first 24 h following reperfusion in patients with STEMI. Three lipid species, namely, acylcarnitine 18:2, TG 51:0, and LPC 17:1 were associated with a change in troponin concentration (delta troponin) and in-hospital cardiovascular events. Of these, acylcarnitine 18:2, and LPC 17:1 and their respective whole class levels, were significantly higher (p < 0.05) in the STEMI population than the age/sex-matched control subjects. Overall, our analyses showed a large shift in plasma lipidome in patients that undergo myocardial reperfusion. The differences found for acylcarnitines and LPC species and their association with both cardiac markers and cardiac outcomes need further validation. Human plasma lipidome rapidly shifts during myocardial reperfusion injury Novel plasma lipids are associated with cardiovascular events Acylcarnitines and lysoPCs correlate with the extent of myocardial injury Acute MI results in elevated plasma AC 18:2 and LPC 17:1 compared to controls
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Affiliation(s)
- Arun Surendran
- Cardiovascular Lipidomics Laboratory, St. Boniface Hospital, Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Mass Spectrometry and Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, 695014 Kerala, India
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
| | - Negar Atefi
- Cardiovascular Lipidomics Laboratory, St. Boniface Hospital, Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
| | - Umar Ismail
- Section of Cardiology, Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
| | - Ashish Shah
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
- Section of Cardiology, Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
| | - Amir Ravandi
- Cardiovascular Lipidomics Laboratory, St. Boniface Hospital, Albrechtsen Research Centre, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
- Section of Cardiology, Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada
- Corresponding author
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4
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Verkerk AO, Knottnerus SJG, Portero V, Bleeker JC, Ferdinandusse S, Guan K, IJlst L, Visser G, Wanders RJA, Wijburg FA, Bezzina CR, Mengarelli I, Houtkooper RH. Electrophysiological Abnormalities in VLCAD Deficient hiPSC-Cardiomyocytes Do not Improve with Carnitine Supplementation. Front Pharmacol 2021; 11:616834. [PMID: 33597881 PMCID: PMC7883678 DOI: 10.3389/fphar.2020.616834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Patients with a deficiency in very long-chain acyl-CoA dehydrogenase (VLCAD), an enzyme that is involved in the mitochondrial beta-oxidation of long-chain fatty acids, are at risk for developing cardiac arrhythmias. In human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), VLCAD deficiency (VLCADD) results in a series of abnormalities, including: 1) accumulation of long-chain acylcarnitines, 2) action potential shortening, 3) higher systolic and diastolic intracellular Ca2+ concentrations, and 4) development of delayed afterdepolarizations. In the fatty acid oxidation process, carnitine is required for bidirectional transport of acyl groups across the mitochondrial membrane. Supplementation has been suggested as potential therapeutic approach in VLCADD, but its benefits are debated. Here, we studied the effects of carnitine supplementation on the long-chain acylcarnitine levels and performed electrophysiological analyses in VLCADD patient-derived hiPSC-CMs with a ACADVL gene mutation (p.Val283Ala/p.Glu381del). Under standard culture conditions, VLCADD hiPSC-CMs showed high concentrations of long-chain acylcarnitines, short action potentials, and high delayed afterdepolarizations occurrence. Incubation of the hiPSC-CMs with 400 µM L-carnitine for 48 h led to increased long-chain acylcarnitine levels both in medium and cells. In addition, carnitine supplementation neither restored abnormal action potential parameters nor the increased occurrence of delayed afterdepolarizations in VLCADD hiPSC-CMs. We conclude that long-chain acylcarnitine accumulation and electrophysiological abnormalities in VLCADD hiPSC-CMs are not normalized by carnitine supplementation, indicating that this treatment is unlikely to be beneficial against cardiac arrhythmias in VLCADD patients.
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Affiliation(s)
- Arie O Verkerk
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Suzan J G Knottnerus
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands.,Department of Pediatric Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | - Vincent Portero
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Jeannette C Bleeker
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands.,Department of Pediatric Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, Dresden, Germany
| | - Lodewijk IJlst
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Gepke Visser
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands.,Department of Pediatric Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Frits A Wijburg
- Department of Pediatric Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Connie R Bezzina
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Isabella Mengarelli
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Riekelt H Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
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5
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Dulz S, Atiskova Y, Engel P, Wildner J, Tsiakas K, Santer R. Retained visual function in a subset of patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). Ophthalmic Genet 2020; 42:23-27. [PMID: 33107778 DOI: 10.1080/13816810.2020.1836658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Introduction: LCHADD causes retinopathy associated with low vision, visual field defects, nyctalopia and myopia. We report a retrospective long-term single-center study of 6 LCHADD patients trying to clarify if early diagnosis has an impact on the course and outcome of chorioretinal degeneration. Methods: Long-term follow-up of visual acuity and staging of chorioretinal degeneration by fundus photography, optical coherence tomography (OCT) and autofluorescence (AF) in all six patients. Three patients (2 m/1 f; age 8-14.8 years) were diagnosed by newborn screening, a single patient early within the first year of life and treated promptly while the other two (1 m/1 f; age 23-24 years) were diagnosed later after developing symptoms. All carried HADHA variants; five were homozygous for the common p.E510Q variant, in one from the symptomatically diagnosed group p.[E510Q]; [R291*] was detected. Results: All patients showed retinal alterations, but early diagnosis was associated with a milder phenotype and a longer preservation of visual function. Among symptomatic patients, only one showed mild retinal involvement at the time of diagnosis. Conclusion: Despite the small number our study suggests that early diagnosis does not prevent retinopathy but might contribute to a milder phenotype with retained good visual acuity over time. OCT and AF are reliable non-invasive diagnostic tools to estimate the progression of early-stage retinal changes in LCHADD patients.
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Affiliation(s)
- Simon Dulz
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
| | - Yevgeniya Atiskova
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
| | - Peter Engel
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
| | - Jan Wildner
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
| | - Konstantinos Tsiakas
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
| | - Rene Santer
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany.,University Children's Hospital, University Medical Center Hamburg-Eppendorf , Hamburg, Germany
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6
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Aitken-Buck HM, Krause J, Zeller T, Jones PP, Lamberts RR. Long-Chain Acylcarnitines and Cardiac Excitation-Contraction Coupling: Links to Arrhythmias. Front Physiol 2020; 11:577856. [PMID: 33041874 PMCID: PMC7518131 DOI: 10.3389/fphys.2020.577856] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/25/2020] [Indexed: 12/31/2022] Open
Abstract
A growing number of metabolomic studies have associated high circulating levels of the amphiphilic fatty acid metabolites, long-chain acylcarnitines (LCACs), with cardiovascular disease (CVD) risk. These studies show that plasma LCAC levels can be correlated with the stage and severity of CVD and with indices of cardiac hypertrophy and ventricular function. Complementing these recent clinical associations is an extensive body of basic research that stems mostly from the twentieth century. These works, performed in cardiomyocyte and multicellular preparations from animal and cell models, highlight stereotypical derangements in cardiac electrophysiology induced by exogenous LCAC treatment that promote arrhythmic muscle behavior. In many cases, this is coupled with acute inotropic modulation; however, whether LCACs increase or decrease contractility is inconclusive. Linked to the electromechanical alterations induced by LCAC exposure is an array of effects on cardiac excitation-contraction coupling mechanisms that overload the cardiomyocyte cytosol with Na+ and Ca2+ ions. The aim of this review is to revisit this age-old literature and collate it with recent findings to provide a pathophysiological context for the growing body of metabolomic association studies that link circulating LCACs with CVD.
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Affiliation(s)
- Hamish M Aitken-Buck
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Julia Krause
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Hamburg, Hamburg, Germany
| | - Tanja Zeller
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Hamburg, Hamburg, Germany
| | - Peter P Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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7
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Snyder J, Zhai R, Lackey AI, Sato PY. Changes in Myocardial Metabolism Preceding Sudden Cardiac Death. Front Physiol 2020; 11:640. [PMID: 32612538 PMCID: PMC7308560 DOI: 10.3389/fphys.2020.00640] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Heart disease is widely recognized as a major cause of death worldwide and is the leading cause of mortality in the United States. Centuries of research have focused on defining mechanistic alterations that drive cardiac pathogenesis, yet sudden cardiac death (SCD) remains a common unpredictable event that claims lives in every age group. The heart supplies blood to all tissues while maintaining a constant electrical and hormonal feedback communication with other parts of the body. As such, recent research has focused on understanding how myocardial electrical and structural properties are altered by cardiac metabolism and the various signaling pathways associated with it. The importance of cardiac metabolism in maintaining myocardial function, or lack thereof, is exemplified by shifts in cardiac substrate preference during normal development and various pathological conditions. For instance, a shift from fatty acid (FA) oxidation to oxygen-sparing glycolytic energy production has been reported in many types of cardiac pathologies. Compounded by an uncoupling of glycolysis and glucose oxidation this leads to accumulation of undesirable levels of intermediate metabolites. The resulting accumulation of intermediary metabolites impacts cardiac mitochondrial function and dysregulates metabolic pathways through several mechanisms, which will be reviewed here. Importantly, reversal of metabolic maladaptation has been shown to elicit positive therapeutic effects, limiting cardiac remodeling and at least partially restoring contractile efficiency. Therein, the underlying metabolic adaptations in an array of pathological conditions as well as recently discovered downstream effects of various substrate utilization provide guidance for future therapeutic targeting. Here, we will review recent data on alterations in substrate utilization in the healthy and diseased heart, metabolic pathways governing cardiac pathogenesis, mitochondrial function in the diseased myocardium, and potential metabolism-based therapeutic interventions in disease.
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Affiliation(s)
- J Snyder
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - R Zhai
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - A I Lackey
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
| | - P Y Sato
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, United States
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8
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Knottnerus SJG, Mengarelli I, Wüst RCI, Baartscheer A, Bleeker JC, Coronel R, Ferdinandusse S, Guan K, IJlst L, Li W, Luo X, Portero VM, Ulbricht Y, Visser G, Wanders RJA, Wijburg FA, Verkerk AO, Houtkooper RH, Bezzina CR. Electrophysiological Abnormalities in VLCAD Deficient hiPSC-Cardiomyocytes Can Be Improved by Lowering Accumulation of Fatty Acid Oxidation Intermediates. Int J Mol Sci 2020; 21:ijms21072589. [PMID: 32276429 PMCID: PMC7177397 DOI: 10.3390/ijms21072589] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/03/2020] [Accepted: 04/05/2020] [Indexed: 12/14/2022] Open
Abstract
Patients with very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) can present with life-threatening cardiac arrhythmias. The pathophysiological mechanism is unknown. We reprogrammed fibroblasts from one mildly and one severely affected VLCADD patient, into human induced pluripotent stem cells (hiPSCs) and differentiated these into cardiomyocytes (VLCADD-CMs). VLCADD-CMs displayed shorter action potentials (APs), more delayed afterdepolarizations (DADs) and higher systolic and diastolic intracellular Ca2+ concentration ([Ca2+]i) than control CMs. The mitochondrial booster resveratrol mitigated the biochemical, electrophysiological and [Ca2+]i changes in the mild but not in the severe VLCADD-CMs. Accumulation of potentially toxic intermediates of fatty acid oxidation was blocked by substrate reduction with etomoxir. Incubation with etomoxir led to marked prolongation of AP duration and reduced DADs and [Ca2+]i in both VLCADD-CMs. These results provide compelling evidence that reduced accumulation of fatty acid oxidation intermediates, either by enhanced fatty acid oxidation flux through increased mitochondria biogenesis (resveratrol) or by inhibition of fatty acid transport into the mitochondria (etomoxir), rescues pro-arrhythmia defects in VLCADD-CMs and open doors for new treatments.
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Affiliation(s)
- Suzan J. G. Knottnerus
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
- Department of Paediatric Metabolic Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands
| | - Isabella Mengarelli
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
| | - Rob C. I. Wüst
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
| | - Antonius Baartscheer
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
| | - Jeannette C. Bleeker
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
- Department of Paediatric Metabolic Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands
| | - Ruben Coronel
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01069 Dresden, Germany; (K.G.); (W.L.); (X.L.); (Y.U.)
| | - Lodewijk IJlst
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
| | - Wener Li
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01069 Dresden, Germany; (K.G.); (W.L.); (X.L.); (Y.U.)
| | - Xiaojing Luo
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01069 Dresden, Germany; (K.G.); (W.L.); (X.L.); (Y.U.)
| | - Vincent M. Portero
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
| | - Ying Ulbricht
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01069 Dresden, Germany; (K.G.); (W.L.); (X.L.); (Y.U.)
| | - Gepke Visser
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
- Department of Paediatric Metabolic Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, 3584 EA Utrecht, The Netherlands
| | - Ronald J. A. Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
| | - Frits A. Wijburg
- Department of Paediatric Metabolic Diseases, Emma Children’s Hospital, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
| | - Arie O. Verkerk
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Riekelt H. Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, 1105 AZ Amsterdam, The Netherlands; (S.J.G.K.); (R.C.I.W.); (J.C.B.); (S.F.); (L.I.); (G.V.); (R.J.A.W.)
- Correspondence: (R.H.H.); (C.R.B.)
| | - Connie R. Bezzina
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands; (I.M.); (A.B.); (R.C.); (V.M.P.); (A.O.V.)
- Correspondence: (R.H.H.); (C.R.B.)
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9
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Sciuto KJ, Deng SW, Venable PW, Warren M, Warren JS, Zaitsev AV. Cyclosporine-insensitive mode of cell death after prolonged myocardial ischemia: Evidence for sarcolemmal permeabilization as the pivotal step. PLoS One 2018; 13:e0200301. [PMID: 29975744 PMCID: PMC6033462 DOI: 10.1371/journal.pone.0200301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/23/2018] [Indexed: 11/18/2022] Open
Abstract
A prominent theory of cell death in myocardial ischemia/reperfusion (I/R) posits that the primary and pivotal step of irreversible cell injury is the opening of the mitochondrial permeability transition (MPT) pore. However, the predominantly positive evidence of protection against infarct afforded by the MPT inhibitor, Cyclosporine A (CsA), in experimental studies is in stark contrast with the overall lack of benefit found in clinical trials of CsA. One reason for the discrepancy might be the fact that relatively short experimental ischemic episodes (<1 hour) do not represent clinically-realistic durations, usually exceeding one hour. Here we tested the hypothesis that MPT is not the primary event of cell death after prolonged (60–80 min) episodes of global ischemia. We used confocal microcopy in Langendorff-perfused rabbit hearts treated with the electromechanical uncoupler, 2,3-Butanedione monoxime (BDM, 20 mM) to allow tracking of MPT and sarcolemmal permeabilization (SP) in individual ventricular myocytes. The time of the steepest drop in fluorescence of mitochondrial membrane potential (ΔΨm)-sensitive dye, TMRM, was used as the time of MPT (TMPT). The time of 20% uptake of the normally cell-impermeable dye, YO-PRO1, was used as the time of SP (TSP). We found that during reperfusion MPT and SP were tightly coupled, with MPT trending slightly ahead of SP (TSP-TMPT = 0.76±1.31 min; p = 0.07). These coupled MPT/SP events occurred in discrete myocytes without crossing cell boundaries. CsA (0.2 μM) did not reduce the infarct size, but separated SP and MPT events, such that detectable SP was significantly ahead of MPT (TSP -TMPT = -1.75±1.28 min, p = 0.006). Mild permeabilization of cells with digitonin (2.5–20 μM) caused coupled MPT/SP events which occurred in discrete myocytes similar to those observed in Control and CsA groups. In contrast, deliberate induction of MPT by titration with H2O2 (200–800 μM), caused propagating waves of MPT which crossed cell boundaries and were uncoupled from SP. Taken together, these findings suggest that after prolonged episodes of ischemia, SP is the primary step in myocyte death, of which MPT is an immediate and unavoidable consequence.
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Affiliation(s)
- Katie J. Sciuto
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Steven W. Deng
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Paul W. Venable
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Mark Warren
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Junco S. Warren
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Internal Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Alexey V. Zaitsev
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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10
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Brunel-Guitton C, Levtova A, Sasarman F. Mitochondrial Diseases and Cardiomyopathies. Can J Cardiol 2015; 31:1360-76. [DOI: 10.1016/j.cjca.2015.08.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/21/2015] [Accepted: 08/21/2015] [Indexed: 12/31/2022] Open
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Houten SM, Violante S, Ventura FV, Wanders RJA. The Biochemistry and Physiology of Mitochondrial Fatty Acid β-Oxidation and Its Genetic Disorders. Annu Rev Physiol 2015; 78:23-44. [PMID: 26474213 DOI: 10.1146/annurev-physiol-021115-105045] [Citation(s) in RCA: 459] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondrial fatty acid β-oxidation (FAO) is the major pathway for the degradation of fatty acids and is essential for maintaining energy homeostasis in the human body. Fatty acids are a crucial energy source in the postabsorptive and fasted states when glucose supply is limiting. But even when glucose is abundantly available, FAO is a main energy source for the heart, skeletal muscle, and kidney. A series of enzymes, transporters, and other facilitating proteins are involved in FAO. Recessively inherited defects are known for most of the genes encoding these proteins. The clinical presentation of these disorders may include hypoketotic hypoglycemia, (cardio)myopathy, arrhythmia, and rhabdomyolysis and illustrates the importance of FAO during fasting and in hepatic and (cardio)muscular function. In this review, we present the current state of knowledge on the biochemistry and physiological functions of FAO and discuss the pathophysiological processes associated with FAO disorders.
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Affiliation(s)
- Sander M Houten
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029; ,
| | - Sara Violante
- Department of Genetics and Genomic Sciences and Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029; ,
| | - Fatima V Ventura
- Metabolism and Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences, iMed.ULisboa, 1649-003 Lisboa, Portugal; .,Department of Biochemistry and Human Biology, Faculty of Pharmacy, University of Lisbon, 1649-003 Lisboa, Portugal
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, University of Amsterdam, 1100 DE Amsterdam, The Netherlands; .,Department of Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
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12
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Abstract
Perturbations in metabolic pathways can cause substantial increases in plasma and tissue concentrations of long-chain acylcarnitines (LCACs). For example, the levels of LCACs and other acylcarnitines rise in the blood and muscle during exercise, as changes in tissue pools of acyl-coenzyme A reflect accelerated fuel flux that is incompletely coupled to mitochondrial energy demand and capacity of the tricarboxylic acid cycle. This natural ebb and flow of acylcarnitine generation and accumulation contrasts with that of inherited fatty acid oxidation disorders (FAODs), cardiac ischaemia or type 2 diabetes mellitus. These conditions are characterized by very high (FAODs, ischaemia) or modestly increased (type 2 diabetes mellitus) tissue and blood levels of LCACs. Although specific plasma concentrations of LCACs and chain-lengths are widely used as diagnostic markers of FAODs, research into the potential effects of excessive LCAC accumulation or the roles of acylcarnitines as physiological modulators of cell metabolism is lacking. Nevertheless, a growing body of evidence has highlighted possible effects of LCACs on disparate aspects of pathophysiology, such as cardiac ischaemia outcomes, insulin sensitivity and inflammation. This Review, therefore, aims to provide a theoretical framework for the potential consequences of tissue build-up of LCACs among individuals with metabolic disorders.
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Affiliation(s)
- Colin S McCoin
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Trina A Knotts
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, CA 95616, USA
| | - Sean H Adams
- Arkansas Children's Nutrition Center and Department of Pediatrics, University of Arkansas for Medical Sciences, 15 Children's Way, Little Rock, AR 72202, USA
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McCoin CS, Knotts TA, Ono-Moore KD, Oort PJ, Adams SH. Long-chain acylcarnitines activate cell stress and myokine release in C2C12 myotubes: calcium-dependent and -independent effects. Am J Physiol Endocrinol Metab 2015; 308:E990-E1000. [PMID: 25852008 PMCID: PMC4451287 DOI: 10.1152/ajpendo.00602.2014] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/06/2015] [Indexed: 01/08/2023]
Abstract
Acylcarnitines, important lipid biomarkers reflective of acyl-CoA status, are metabolites that possess bioactive and inflammatory properties. This study examined the potential for long-chain acylcarnitines to activate cellular inflammatory, stress, and death pathways in a skeletal muscle model. Differentiated C2C12 myotubes treated with l-C14, C16, C18, and C18:1 carnitine displayed dose-dependent increases in IL-6 production with a concomitant rise in markers of cell permeability and death, which was not observed for shorter chain lengths. l-C16 carnitine, used as a representative long-chain acylcarnitine at initial extracellular concentrations ≥25 μM, increased IL-6 production 4.1-, 14.9-, and 31.4-fold over vehicle at 25, 50, and 100 μM. Additionally, l-C16 carnitine activated c-Jun NH2-terminal kinase, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase between 2.5- and 11-fold and induced cell injury and death within 6 h with modest activation of the apoptotic caspase-3 protein. l-C16 carnitine rapidly increased intracellular calcium, most clearly by 10 μM, implicating calcium as a potential mechanism for some activities of long-chain acylcarnitines. The intracellular calcium chelator BAPTA-AM blunted l-C16 carnitine-mediated IL-6 production by >65%. However, BAPTA-AM did not attenuate cell permeability and death responses, indicating that these outcomes are calcium independent. The 16-carbon zwitterionic compound amidosulfobetaine-16 qualitatively mimicked the l-C16 carnitine-associated cell stress outcomes, suggesting that the effects of high experimental concentrations of long-chain acylcarnitines are through membrane disruption. Herein, a model is proposed in which acylcarnitine cell membrane interactions take place along a spectrum of cellular concentrations encountered in physiological-to-pathophysiological conditions, thus regulating function of membrane-based systems and impacting cell biology.
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Affiliation(s)
- Colin S McCoin
- Molecular, Cellular and Integrative Physiology Graduate Group, University of California, Davis, California
| | - Trina A Knotts
- Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA; Department of Nutrition, University of California, Davis, Davis, California; and
| | - Kikumi D Ono-Moore
- Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA
| | - Pieter J Oort
- Obesity & Metabolism Research Unit, United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, CA
| | - Sean H Adams
- Molecular, Cellular and Integrative Physiology Graduate Group, University of California, Davis, California; Department of Nutrition, University of California, Davis, Davis, California; and Arkansas Children's Nutrition Center and Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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14
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Roussel J, Thireau J, Brenner C, Saint N, Scheuermann V, Lacampagne A, Le Guennec JY, Fauconnier J. Palmitoyl-carnitine increases RyR2 oxidation and sarcoplasmic reticulum Ca2+ leak in cardiomyocytes: Role of adenine nucleotide translocase. Biochim Biophys Acta Mol Basis Dis 2015; 1852:749-58. [DOI: 10.1016/j.bbadis.2015.01.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 01/16/2015] [Accepted: 01/18/2015] [Indexed: 12/30/2022]
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To KKW, Lee KC, Wong SSY, Lo KC, Lui YM, Jahan AS, Wu AL, Ke YH, Law CY, Sze KH, Lau SKP, Woo PCY, Lam CW, Yuen KY. Lipid mediators of inflammation as novel plasma biomarkers to identify patients with bacteremia. J Infect 2015; 70:433-44. [PMID: 25727996 DOI: 10.1016/j.jinf.2015.02.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Rapid diagnostic tests for bacteremia are important for early treatment to improve clinical outcome. We sought to identify plasma biomarkers that can identify patients with bacteremia using an untargeted global metabolomic analysis. METHODS Plasma metabolomic profiles were analyzed for 145 adult patients with (cases) and without (controls) bacteremia using ultra-high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). All metabolites were compared between cases and controls using a 2-tier filtering approach, and each metabolite underwent receiver operating characteristic (ROC) curve analysis. Individual metabolites that distinguish between cases and controls were characterized. Subgroup analysis was performed to identify metabolites with prognostic significance. RESULTS After 2-tier filtering, 128 molecular features were identified to be potential biomarkers that could distinguish cases from controls. Five metabolites had an area under the ROC curve (AUC) of >0.8 in ROC curve analysis, including a sphingolipid, an acylcarnitine, a fatty acid ester, and 2 glycerophosphocholines. These metabolites could distinguish cases from controls in the unsupervised hierarchical clustering analysis. Subgroup analysis of bacteremic patients showed that the level of trans-2,3,4-trimethoxycinnamate was lower in fatal than non-fatal cases. CONCLUSIONS Plasma lipid mediators of inflammation can distinguish bacteremia cases from non-bacteremia controls. These biomarkers may be used as targets for rapid test in clinical practice.
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Affiliation(s)
- Kelvin K W To
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Kim-Chung Lee
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Samson S Y Wong
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ka-Ching Lo
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Yin-Ming Lui
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Akhee S Jahan
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Andrea L Wu
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Yi-Hong Ke
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Chun-Yiu Law
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Kong-Hung Sze
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Susanna K P Lau
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Patrick C Y Woo
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Ching-Wan Lam
- Department of Pathology, The University of Hong Kong, Hong Kong, China
| | - Kwok-Yung Yuen
- State Key Laboratory for Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China; Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China; Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China; Department of Microbiology, The University of Hong Kong, Hong Kong, China.
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16
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Hisahara S, Matsushita T, Furuyama H, Tajima G, Shigematsu Y, Imai T, Shimohama S. A Heterozygous Missense Mutation in Adolescent-Onset Very Long-Chain Acyl-CoA Dehydrogenase Deficiency with Exercise-Induced Rhabdomyolysis. TOHOKU J EXP MED 2015; 235:305-10. [DOI: 10.1620/tjem.235.305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Shin Hisahara
- Department of Neurology, School of Medicine, Sapporo Medical University
| | | | | | - Go Tajima
- Department of Pediatrics, Hiroshima University Graduate School of Biomedical Sciences & Health Sciences
| | - Yosuke Shigematsu
- Department of Health Science, Faculty of Medical Sciences, University of Fukui
| | - Tomihiro Imai
- Department of Occupational Therapy, School of Health Sciences, Sapporo Medical University
- Department of Neurology, School of Medicine, Sapporo Medical University
| | - Shun Shimohama
- Department of Neurology, School of Medicine, Sapporo Medical University
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17
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Scalais E, Bottu J, Wanders RJA, Ferdinandusse S, Waterham HR, De Meirleir L. Familial very long chain acyl-CoA dehydrogenase deficiency as a cause of neonatal sudden infant death: Improved survival by prompt diagnosis. Am J Med Genet A 2014; 167A:211-4. [DOI: 10.1002/ajmg.a.36803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 09/08/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Emmanuel Scalais
- Division of Pediatric Neurology; Department of Pediatrics; Centre Hospitalier de Luxembourg; Luxembourg City Luxembourg
| | - Jean Bottu
- Neonatal Intensive Care; Centre Hospitalier de Luxembourg; Luxembourg City Luxembourg
| | - Ronald J. A. Wanders
- Laboratory Genetic Metabolic Diseases; Department of Pediatrics and Clinical Chemistry; Academic Medical Center; University of Amsterdam; Amsterdam Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases; Department of Pediatrics and Clinical Chemistry; Academic Medical Center; University of Amsterdam; Amsterdam Netherlands
| | - Hans R. Waterham
- Laboratory Genetic Metabolic Diseases; Department of Pediatrics and Clinical Chemistry; Academic Medical Center; University of Amsterdam; Amsterdam Netherlands
| | - Linda De Meirleir
- UZ Brussels Pediatric Neurology and Metabolism; Vrije Universiteit Brussels; Brussels Belgium
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18
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Lipid metabolites and their differential pro-arrhythmic profiles: of importance in the development of a new anti-arrhythmic pharmacology. Mol Cell Biochem 2014; 393:191-7. [DOI: 10.1007/s11010-014-2060-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 04/11/2014] [Indexed: 01/12/2023]
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Tonin AM, Amaral AU, Busanello ENB, Grings M, Castilho RF, Wajner M. Long-chain 3-hydroxy fatty acids accumulating in long-chain 3-hydroxyacyl-CoA dehydrogenase and mitochondrial trifunctional protein deficiencies uncouple oxidative phosphorylation in heart mitochondria. J Bioenerg Biomembr 2012; 45:47-57. [PMID: 23065309 DOI: 10.1007/s10863-012-9481-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/02/2012] [Indexed: 11/30/2022]
Abstract
Cardiomyopathy is a common clinical feature of some inherited disorders of mitochondrial fatty acid β-oxidation including mitochondrial trifunctional protein (MTP) and isolated long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiencies. Since individuals affected by these disorders present tissue accumulation of various fatty acids, including long-chain 3-hydroxy fatty acids, in the present study we investigated the effect of 3-hydroxydecanoic (3 HDCA), 3-hydroxydodecanoic (3 HDDA), 3-hydroxytetradecanoic (3 HTA) and 3-hydroxypalmitic (3 HPA) acids on mitochondrial oxidative metabolism, estimated by oximetry, NAD(P)H content, hydrogen peroxide production, membrane potential (ΔΨ) and swelling in rat heart mitochondrial preparations. We observed that 3 HTA and 3 HPA increased resting respiration and diminished the respiratory control and ADP/O ratios using glutamate/malate or succinate as substrates. Furthermore, 3 HDDA, 3 HTA and 3 HPA decreased ΔΨ, the matrix NAD(P)H pool and hydrogen peroxide production. These data indicate that these fatty acids behave as uncouplers of oxidative phosphorylation. We also verified that 3 HTA-induced uncoupling-effect was not mediated by the adenine nucleotide translocator and that this fatty acid induced the mitochondrial permeability transition pore opening in calcium-loaded organelles since cyclosporin A prevented the reduction of mitochondrial ΔΨ and swelling provoked by 3 HTA. The present data indicate that major 3-hydroxylated fatty acids accumulating in MTP and LCHAD deficiencies behave as strong uncouplers of oxidative phosphorylation potentially impairing heart energy homeostasis.
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Affiliation(s)
- Anelise M Tonin
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, RS, Brazil
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20
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Sponseller BT, Valberg SJ, Schultz NE, Bedford H, Wong DM, Kersh K, Shelton GD. Equine multiple acyl-CoA dehydrogenase deficiency (MADD) associated with seasonal pasture myopathy in the midwestern United States. J Vet Intern Med 2012; 26:1012-8. [PMID: 22708588 DOI: 10.1111/j.1939-1676.2012.00957.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/16/2012] [Accepted: 05/09/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Seasonal pasture myopathy (SPM) is a highly fatal form of nonexertional rhabdomyolysis that occurs in pastured horses in the United States during autumn or spring. In Europe, a similar condition, atypical myopathy (AM), is common. Recently, a defect of lipid metabolism, multiple acyl-CoA dehydrogenase deficiency (MADD), has been identified in horses with AM. OBJECTIVE To determine if SPM in the United States is caused by MADD. ANIMALS Six horses diagnosed with SPM based on history, clinical signs, and serum creatine kinase activity, or postmortem findings. METHODS Retrospective descriptive study. Submissions to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were reviewed between April 2009 and January 2010 to identify cases of SPM. Inclusion criteria were pastured, presenting with acute nonexertional rhabdomyolysis, and serum, urine, or muscle samples available for analysis. Horses were evaluated for MADD by urine organic acids, serum acylcarnitines, muscle carnitine, or histopathology. RESULTS Six horses had clinical signs and, where performed (4/6 horses), postmortem findings consistent with SPM. Affected muscle (4/4) showed degeneration with intramyofiber lipid accumulation, decreased free carnitine concentration, and increased carnitine esters. Serum acylcarnitine profiles (3/3) showed increases in short- and medium-chain acylcarnitines and urinary organic acid profiles (3/3) revealed increased ethylmalonic and methylsuccinic acid levels, and glycine conjugates, consistent with equine MADD. CONCLUSIONS AND CLINICAL IMPORTANCE Similar to AM, the biochemical defect causing SPM is MADD, which causes defective muscular lipid metabolism and excessive myofiber lipid content. Diagnosis can be made by assessing serum acylcarnitine and urine organic acid profiles.
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Affiliation(s)
- B T Sponseller
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Neckář J, Šilhavy J, Zídek V, Landa V, Mlejnek P, Šimáková M, Seidman JG, Seidman C, Kazdová L, Klevstig M, Novák F, Vecka M, Papoušek F, Houštěk J, Drahota Z, Kurtz TW, Kolář F, Pravenec M. CD36 overexpression predisposes to arrhythmias but reduces infarct size in spontaneously hypertensive rats: gene expression profile analysis. Physiol Genomics 2012; 44:173-82. [PMID: 22128087 PMCID: PMC3289117 DOI: 10.1152/physiolgenomics.00083.2011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
CD36 fatty acid translocase plays a key role in supplying heart with its major energy substrate, long-chain fatty acids (FA). Previously, we found that the spontaneously hypertensive rat (SHR) harbors a deletion variant of Cd36 gene that results in reduced transport of long-chain FA into cardiomyocytes and predisposes the SHR to cardiac hypertrophy. In the current study, we analyzed the effects of mutant Cd36 on susceptibility to ischemic ventricular arrhythmias and myocardial infarction in adult SHR-Cd36 transgenic rats with wild-type Cd36 compared with age-matched SHR controls. Using an open-chest model of coronary artery occlusion, we found that SHR-Cd36 transgenic rats showed profound arrhythmogenesis resulting in significantly increased duration of tachyarrhythmias (207 ± 48 s vs. 55 ± 21 s, P < 0.05), total number of premature ventricular complexes (2,623 ± 517 vs. 849 ± 250, P < 0.05) and arrhythmia score (3.86 ± 0.18 vs. 3.13 ± 0.13, P < 0.001). On the other hand, transgenic SHR compared with SHR controls showed significantly reduced infarct size (52.6 ± 4.3% vs. 72.4 ± 2.9% of area at risk, P < 0.001). Similar differences were observed in isolated perfused hearts, and the increased susceptibility of transgenic SHR to arrhythmias was abolished by reserpine, suggesting the involvement of catecholamines. To further search for possible molecular mechanisms of altered ischemic tolerance, we compared gene expression profiles in left ventricles dissected from 6-wk-old transgenic SHR vs. age-matched controls using Illumina-based sequencing. Circadian rhythms and oxidative phosphorylation were identified as the top KEGG pathways, while circadian rhythms, VDR/RXR activation, IGF1 signaling, and HMGB1 signaling were the top IPA canonical pathways potentially important for Cd36-mediated effects on ischemic tolerance. It can be concluded that transgenic expression of Cd36 plays an important role in modulating the incidence and severity of ischemic and reperfusion ventricular arrhythmias and myocardial infarct size induced by coronary artery occlusion. The proarrhythmic effect of Cd36 transgene appears to be dependent on adrenergic stimulation.
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Affiliation(s)
- Jan Neckář
- Institute of Physiology, Academy of Sciences of the Czech Republic, Czech Republic
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Houten SM, Wanders RJA. A general introduction to the biochemistry of mitochondrial fatty acid β-oxidation. J Inherit Metab Dis 2010; 33:469-77. [PMID: 20195903 PMCID: PMC2950079 DOI: 10.1007/s10545-010-9061-2] [Citation(s) in RCA: 600] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 10/14/2009] [Accepted: 01/28/2010] [Indexed: 12/30/2022]
Abstract
Over the years, the mitochondrial fatty acid β-oxidation (FAO) pathway has been characterised at the biochemical level as well as the molecular biological level. FAO plays a pivotal role in energy homoeostasis, but it competes with glucose as the primary oxidative substrate. The mechanisms behind this so-called glucose-fatty acid cycle operate at the hormonal, transcriptional and biochemical levels. Inherited defects for most of the FAO enzymes have been identified and characterised and are currently included in neonatal screening programmes. Symptoms range from hypoketotic hypoglycaemia to skeletal and cardiac myopathies. The pathophysiology of these diseases is still not completely understood, hampering optimal treatment. Studies of patients and mouse models will contribute to our understanding of the pathogenesis and will ultimately lead to better treatment.
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Affiliation(s)
- Sander Michel Houten
- Department of Clinical Chemistry, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Spiekerkoetter U, Bastin J, Gillingham M, Morris A, Wijburg F, Wilcken B. Current issues regarding treatment of mitochondrial fatty acid oxidation disorders. J Inherit Metab Dis 2010; 33:555-61. [PMID: 20830526 DOI: 10.1007/s10545-010-9188-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 07/27/2010] [Accepted: 08/06/2010] [Indexed: 12/13/2022]
Abstract
Treatment recommendations in mitochondrial fatty acid oxidation (FAO) defects are diverse. With implementation of newborn screening and identification of asymptomatic patients, it is necessary to define whom to treat and how strictly. We here discuss critical questions that are currently under debate. For some asymptomatic long-chain defects, long-chain fat restriction plays a minor role, and a normal diet may be introduced. For patients presenting only with myopathic symptoms, e.g., during exercise, treatment may be adapted to energy demand. As a consequence, patients with exercise-induced myopathy may be able to return to normal activity when provided with medium-chain triglycerides (MCT) prior to exercise. There is no need to limit participation in sports. Progression of retinopathy in disorders of the mitochondrial trifunctional protein complex is closely associated with hydroxyacylcarnitine accumulation. A strict low-fat diet with MCT supplementation is recommended to slow or prevent progression of chorioretinopathy. Additional docosahexanoic acid does not prevent the decline in retinal function but does promote nonspecific improvement in visual acuity and is recommended. There is no evidence that L-carnitine supplementation is beneficial. Thus, supplementation with L-carnitine in a newborn identified by screening with either a medium-chain or long-chain defect is not supported. With respect to the use of the odd-chain medium-chain triglyceride triheptanoin in myopathic phenotypes, randomized trials are needed to establish whether triheptanoin is more effective than even-chain MCT. With increasing pathophysiological knowledge, new treatment options have been identified and are being clinically evaluated. These include the use of bezafibrates in myopathic long-chain defects.
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Affiliation(s)
- Ute Spiekerkoetter
- Department of General Pediatrics, University Children's Hospital, Duesseldorf, Germany.
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Son NH, Yu S, Tuinei J, Arai K, Hamai H, Homma S, Shulman GI, Abel ED, Goldberg IJ. PPARγ-induced cardiolipotoxicity in mice is ameliorated by PPARα deficiency despite increases in fatty acid oxidation. J Clin Invest 2010; 120:3443-54. [PMID: 20852389 DOI: 10.1172/jci40905] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 07/21/2010] [Indexed: 01/13/2023] Open
Abstract
Excess lipid accumulation in the heart is associated with decreased cardiac function in humans and in animal models. The reasons are unclear, but this is generally believed to result from either toxic effects of intracellular lipids or excessive fatty acid oxidation (FAO). PPARγ expression is increased in the hearts of humans with metabolic syndrome, and use of PPARγ agonists is associated with heart failure. Here, mice with dilated cardiomyopathy due to cardiomyocyte PPARγ overexpression were crossed with PPARα-deficient mice. Surprisingly, this cross led to enhanced expression of several PPAR-regulated genes that mediate fatty acid (FA) uptake/oxidation and triacylglycerol (TAG) synthesis. Although FA oxidation and TAG droplet size were increased, heart function was preserved and survival improved. There was no marked decrease in cardiac levels of triglyceride or the potentially toxic lipids diacylglycerol (DAG) and ceramide. However, long-chain FA coenzyme A (LCCoA) levels were increased, and acylcarnitine content was decreased. Activation of PKCα and PKCδ, apoptosis, ROS levels, and evidence of endoplasmic reticulum stress were also reduced. Thus, partitioning of lipid to storage and oxidation can reverse cardiolipotoxicity despite increased DAG and ceramide levels, suggesting a role for other toxic intermediates such as acylcarnitines in the toxic effects of lipid accumulation in the heart.
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Affiliation(s)
- Ni-Huiping Son
- Division of Preventive Medicine and Nutrition, Columbia University, New York, New York 10032, USA
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Lin YK, Chen YJ, Chen SA. Potential atrial arrhythmogenicity of adipocytes: Implications for the genesis of atrial fibrillation. Med Hypotheses 2010; 74:1026-9. [DOI: 10.1016/j.mehy.2010.01.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 01/10/2010] [Indexed: 01/04/2023]
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Tappia PS, Asemu G, Rodriguez-Leyva D. Phospholipase C as a potential target for cardioprotection during oxidative stressThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease. Can J Physiol Pharmacol 2010; 88:249-63. [DOI: 10.1139/y10-019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cardiac dysfunction due to ischemia–reperfusion (I/R) is associated with marked changes in membrane function and subsequent Ca2+-handling abnormalities in cardiomyocytes. The membrane abnormalities in hearts subjected to I/R arise primarily from oxidative stress as a consequence of increased formation of reactive oxygen species and other oxidants, as well as reduced antioxidant defenses. Little is known, however, about the nature and mechanisms of the sarcolemmal membrane changes with respect to phospholipase C (PLC)-related signaling events. In addition, the mechanisms involved in protection of the postischemic myocardium and in ischemic preconditioning with respect to PLC function need to be established. Accordingly, this article reviews the historical and current information on PLC-mediated signal transduction mechanisms in I/R, as well as outlining future directions that should be addressed. Such information will extend our knowledge of ischemic heart disease and help improve its therapy.
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Affiliation(s)
- Paramjit S. Tappia
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Girma Asemu
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Delfin Rodriguez-Leyva
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
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Clements-Jewery H, Andrag E, Curtis MJ. Druggable targets for sudden cardiac death prevention: lessons from the past and strategies for the future. Curr Opin Pharmacol 2009; 9:146-53. [PMID: 19167272 DOI: 10.1016/j.coph.2008.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 12/02/2008] [Accepted: 12/04/2008] [Indexed: 12/19/2022]
Abstract
Sudden cardiac death (SCD) is most commonly caused by ventricular fibrillation (VF). The single largest cohort of victims is the population with little or no prior overt heart disease. Effective prevention will require long-term prophylaxis by drugs in large numbers of people identified by risk factors. This means that safe as well as effective drugs are required. Drugs with overt effects on cardiac electrophysiology have failed in the clinic owing to poor effectiveness and/or adverse effects. This article examines possible new drug targets. We have focused on acute myocardial ischaemia as it is the most strikingly proarrhythmic pathology, and the most common cause of coronary artery disease-related VF and SCD according to inferences from epidemiology, drug trials and decades of animal research. To set the scene we have briefly explored drugs that have failed in the clinic in order to identify possible targets that have been overlooked or underexploited. We conclude that the best strategy is identification of pathology-specific targets that render drugs active only where and when their action is required.
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El-Beshlawy A, Youssry I, El-Saidi S, El Accaoui R, Mansi Y, Makhlouf A, Taher A. Pulmonary hypertension in beta-thalassemia major and the role of L-carnitine therapy. Pediatr Hematol Oncol 2008; 25:734-43. [PMID: 19065439 DOI: 10.1080/08880010802244035] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Cardiac complications, such as pulmonary hypertension (PHT), are the leading cause of death in beta-thalassemia patients. L-Carnitine, due to its role in fatty acid oxidation, might help control the elevation in pulmonary artery systolic pressure (PASP). The objectives of this study were to assess the prevalence of PHT in beta-thalassemia major patients, identify clinical predictors for its development, and determine the potential effects of L-carnitine. In total, 32 patients with beta-thalassemia major were recruited; 16 age- and sex-matched children constituted the control group. Cardiac evaluation was performed by using echocardiography. The patients with PHT received 50 mg/kg/day L-carnitine orally for 3 months and were then reevaluated. Based on PASP, the patients were divided into group A without PHT and group B with PHT. The prevalence of PHT was 37.5%. The other echocardiographic measurements were not significantly different between groups A and B. PASP did not have any significant correlation with the following variables: age, total number of blood units received, splenic status, serum ferritin level, and ejection fraction. Following the administration of L-carnitine, there was a significant decrease in the mean PASP from 33.96 +/- 7.85 to 24.11 +/- 7.61. All cardiac dimensions decreased following L-carnitine, but the changes were not statistically significant. Even though beta-thalassemia major resulted in an elevation in the PASP in only a fraction of the patients, it seems to have an impact on the heart dimensions and function of all patients. No clinical predictors were identified. Oral administration of L-carnitine appears to significantly improve PASP.
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PRIORI SILVIAG, CORR PETERB. The Importance of α-Adrenergic Stimulation of Cardiac Tissue and its Contribution to Arrhythmogenesis During Ischemia. J Cardiovasc Electrophysiol 2008. [DOI: 10.1111/j.1540-8167.1990.tb01087.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yang Q, Li Y. Roles of PPARs on regulating myocardial energy and lipid homeostasis. J Mol Med (Berl) 2007; 85:697-706. [PMID: 17356846 DOI: 10.1007/s00109-007-0170-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 01/19/2007] [Accepted: 02/23/2007] [Indexed: 12/13/2022]
Abstract
Myocardial energy and lipid homeostasis is crucial for normal cardiac structure and function. Either shortage of energy or excessive lipid accumulation in the heart leads to cardiac disorders. Peroxisome proliferator-activated receptors (PPARalpha, -beta/delta and -gamma), members of the nuclear receptor transcription factor superfamily, play important roles in regulating lipid metabolic genes. All three PPAR subtypes are expressed in cardiomyocytes. PPARalpha has been shown to control transcriptional expression of key enzymes that are involved in fatty acid (FA) uptake and oxidation, triglyceride synthesis, mitochondrial respiration uncoupling, and glucose metabolism. Similarly, PPARbeta/delta is a transcriptional regulator of FA uptake and oxidation, mitochondrial respiration uncoupling, and glucose metabolism. On the other hand, the role of PPARgamma on transcriptional regulation of FA metabolism in the heart remains obscure. Therefore, both PPARalpha and PPARbeta/delta are important transcriptional regulators of myocardial energy and lipid homeostasis. Moreover, it appears that the heart needs to have two PPAR subtypes with seemingly overlapping functions in maintaining myocardial lipid and energy homeostasis. Further studies on the potential distinctive roles of each PPAR subtype in the heart should provide new therapeutic targets for treating heart disease.
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Affiliation(s)
- Qinglin Yang
- Cardiovascular Research Institute, Morehouse School of Medicine, 720 Westview Dr SW, Atlanta, GA 30310, USA.
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Meyer MC, McHowat J. Calcium-independent phospholipase A2-catalyzed plasmalogen hydrolysis in hypoxic human coronary artery endothelial cells. Am J Physiol Cell Physiol 2007; 292:C251-8. [PMID: 16943248 DOI: 10.1152/ajpcell.00120.2006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Thrombin stimulation of human coronary artery endothelial cells (HCAEC) results in activation of a membrane-associated, calcium-independent phospholipase A2(iPLA2) that selectively hydrolyzes membrane plasmalogen phospholipids. Rupture of an atherosclerotic plaque and occlusion of the coronary vasculature results in a coronary ischemic event in which HCAEC in the ischemic area would be exposed to dramatic decreases in oxygen tension in addition to thrombin exposure. We exposed HCAEC to hypoxia in the presence or absence of thrombin stimulation and measured iPLA2activation, membrane phospholipid hydrolysis, and the accumulation of biologically active phospholipid metabolites. HCAEC exposed to hypoxia, thrombin stimulation, or a combination of the two conditions demonstrated an increase in iPLA2activity and an increase in arachidonic acid release from plasmenylcholine. Thrombin stimulation of normoxic HCAEC did not result in an accumulation of choline lysophospholipids, but hypoxia alone and in combination with thrombin stimulation led to a significant accumulation of lysoplasmenylcholine (LPlsCho). We propose that the presence of hypoxia inhibits LPlsCho catabolism, at least in part, as a result of the accumulation of long-chain acylcarnitines. The combination of increased production and decreased catabolism of LPlsCho is necessary for its accumulation. Pretreatment with bromoenol lactone to inhibit iPLA2blocked membrane phospholipid hydrolysis and production of membrane phospholipid-derived metabolites. The increase in iPLA2activity and the subsequent accumulation of membrane phospholipid-derived metabolites in HCAEC exposed to hypoxia or thrombin stimulation alone, and particularly in combination, have important implications in inflammation and arrhythmogenesis in atherosclerosis/thrombosis and subsequent myocardial ischemia.
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Affiliation(s)
- Maureen C Meyer
- Department of Pathology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., St. Louis, MO 63104, USA
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El-Beshlawy A, El Accaoui R, Abd El-Sattar M, Gamal El-Deen MH, Youssry I, Shaheen N, Hamdy M, El-Ghamrawy M, Taher A. Effect of L-carnitine on the physical fitness of thalassemic patients. Ann Hematol 2006; 86:31-4. [PMID: 17031691 DOI: 10.1007/s00277-006-0181-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 07/18/2006] [Indexed: 02/06/2023]
Abstract
Poor physical fitness is a common problem among thalassemic patients. L-Carnitine plays an essential role in fatty acid beta-oxidation, a process especially important in the organs that preferentially use fatty acid as a source of energy such as the myocardium and the skeletal muscles. The main objective of this study is to assess the effect of the administration of oral L-carnitine on exercise tolerance and physical fitness in patients with thalassemia major. Thirty patients followed up at the New Cairo University Children Hospital were included in this study. Clinical, laboratory, and cardiopulmonary exercise testing were performed before and after 6 months of oral L-carnitine therapy (50 mg/kg/day). The oxygen consumption, cardiac output, and oxygen pulse at maximal exercise significantly increased after L-carnitine therapy (p<0.001, p=0.002 and p<0.001, respectively). However, there was no significant change in minute ventilation and ventilatory equivalent of carbon dioxide (p=0.07 and p=0.06, respectively). A weak but positive correlation between the age of the patients and the degree of improvement in exercise parameters was noted. There was also significant increase in the blood transfusion intervals after L-carnitine administration (p=0.008). However, there was no significant change in hemoglobin concentration (p=0.4). L-Carnitine seems to be a safe and effective adjunctive therapeutic approach in thalassemic patients. It improves their cardiac performance and physical fitness. The younger the patients are, the higher is the degree of improvement in their exercise parameters.
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Affiliation(s)
- Amal El-Beshlawy
- Department of Pediatrics, New Children Hospital, Cairo University, Cairo, Egypt
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Ahlen K, Buckley CJ, Goodale DB, Pulsford AH. The 'propofol infusion syndrome': the facts, their interpretation and implications for patient care. Eur J Anaesthesiol 2006; 23:990-8. [PMID: 16938158 DOI: 10.1017/s0265021506001281] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2006] [Indexed: 02/03/2023]
Abstract
AstraZeneca (the manufacturer of Diprivan) presents its review of the history of the so-called 'propofol infusion syndrome', highlighting the difficulties in analysing the incomplete information available. Theories as to its causality are presented and discussed; these include mitochondrial toxicity, mitochondrial defects, impaired tissue oxygenation and carbohydrate deficiency. A review of published and confidential safety data is presented and discussed; it concludes that the major risk factors for its development appear to be poor oxygen delivery, sepsis, serious cerebral injury and high propofol dosage. In some reports an increasing lipaemia was noted and was likely to be due to a failure of hepatic lipid regulation, possibly related to poor oxygenation and/or possibly a lack of glucose. In some cases an increasing lipaemia was the first indication of impending 'propofol infusion syndrome' onset and it should not be viewed as a benign sign. The lipaemia can lead to sequestration of propofol into the lipid phase, leading to lowered free propofol levels and apparent insensitivity to propofol. In conclusion AstraZeneca advocates good haemodynamic and oxygen delivery management, adequate glucose provision, adherence to recommended propofol dosing regimes together with active management of lipaemias to both prevent and treat 'propofol infusion syndrome'.
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Affiliation(s)
- K Ahlen
- AstraZeneca R&D, Clinical Science, Sweden
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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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Abstract
The metabolic pathways of the heart during normoxia and ischemia have been well studied. High plasma fatty acid concentrations and the myocardial accumulation of long-chain fatty acyl metabolites during ischemia correlate with increased morbidity and mortality. However, enhanced glucose use can maintain cell homeostasis, diminish ischemic injury, and be clinically beneficial. Metabolic modulators represent a new class of drugs with the potential to treat myocardial ischemia. They are ideal as adjunctive anti-ischemic therapy because they lack the hemodynamic consequences of traditional therapy and treat the underlying metabolic dysfunction that leads to contractile failure and arrhythmias. Clinical studies have demonstrated their efficacy in acute and chronic settings. It is anticipated that there will be greater utilization of this new class of agents in the near future.
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Affiliation(s)
- Sonal Jani
- Division of Cardiology, Beth Israel Medical Center, Baird 5, 16th Street and First Avenue, New York, NY 10003, USA
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Leonard JV, Morris AAM. Diagnosis and early management of inborn errors of metabolism presenting around the time of birth. Acta Paediatr 2006; 95:6-14. [PMID: 16373289 DOI: 10.1080/08035250500349413] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UNLABELLED Inherited metabolic diseases often present around the time of birth. They are responsible for some cases of hydrops fetalis and a number of dysmorphic syndromes. Patients with inborn errors may also present at (or shortly after) birth with seizures or severe hypotonia. Most affected babies, however, appear normal at birth and subsequently deteriorate, with hypoglycaemia, acidosis, neurological or cardiac problems, or liver disease. Treatment often involves measures to reduce catabolism and to remove toxic metabolites. It should not be delayed for a definitive diagnosis. CONCLUSION In the newborn period, inborn errors can easily be misdiagnosed as sepsis or birth asphyxia; prompt detection requires vigilance and the early measurement of biochemical markers, such as plasma ammonia.
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Affiliation(s)
- James V Leonard
- Biochemistry, Endocrinology and Metabolism Unit, Institute of Child Health, London, UK.
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Affiliation(s)
- Ronald M Witteles
- Stanford University School of Medicine, Stanford, CA 94305-5406, USA
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Exil VJ, Summar M, Boles MA, Atkinson J, Johns JA, Matern D, Strauss AW, Canter CE. Metabolic basis of pediatric heart disease. PROGRESS IN PEDIATRIC CARDIOLOGY 2005. [DOI: 10.1016/j.ppedcard.2005.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Goikoetxea MJ, Beaumont J, Díez J. Peroxisome proliferator-activated receptor alpha and hypertensive heart disease. Drugs 2005; 64 Suppl 2:9-18. [PMID: 15765888 DOI: 10.2165/00003495-200464002-00003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. It is expressed by cardiomyocytes and regulates gene expression of key proteins involved in myocardial lipid and energy metabolism. Accordingly, the activitity of PPARalpha is an important determinant of cardiomyocyte lipid homeostasis and ATP production. Currently, animal and human data suggest that deactivation of PPARalpha may contribute substantially to phenotypic changes that accompany cardiac growth in conditions of pressure overload, and the hypothesis emerges that a compromised PPARalpha activity may participate in the transition from compensated left ventricular hypertrophy to heart failure in hypertensive heart disease. The availability of PPARalpha activators (e.g. fibric acid derivates and statins) must stimulate investigation into the potential cardioprotective actions of these compounds beyond their hypolipidaemic effects and via restoration of PPARalpha activity in the hypertrophied and failing heart.
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Affiliation(s)
- Maria J Goikoetxea
- Area of Cardiovascular Pathophysiology, Centre for Applied Medical Research, University Clinic, School of Medicine, University of Navarra, Pamplona, Spain
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Cui J, Das DK, Bertelli A, Tosaki A. Effects of L-carnitine and its derivatives on postischemic cardiac function, ventricular fibrillation and necrotic and apoptotic cardiomyocyte death in isolated rat hearts. Mol Cell Biochem 2004; 254:227-34. [PMID: 14674702 DOI: 10.1023/a:1027368018064] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The study aimed to examine whether L-carnitine and its derivatives, acetyl-L-carnitine and propionyl-L-carnitine, were equally effective and able to improve postischemic cardiac function, reduce the incidence of reperfusion-induced ventricular fibrillation, infarct size, and apoptotic cell death in ischemic/reperfused isolated rat hearts. There are several studies indicating that L-carnitine, a naturally occurring amino acid and an essential cofactor, can improve mechanical function and substrate metabolism not only in hypertrophied or failing myocardium but also in ischemic/reperfused hearts. The effects of L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine, on the recovery of heart function, incidence of reperfusion-induced ventricular fibrillation (VF), infarct size, and apoptotic cell death after 30 min ischemia followed by 120 min reperfusion were studied in isolated working rat hearts. Hearts were perfused with various concentrations of L-carnitine (0.5 and 5 mM), acetyl-L-carnitine (0.5 and 5 mM), and propionyl-L-carnitine (0.05, 0.5, and 5 mM), respectively, for 10 min before the induction of ischemia. Postischemic recovery of CF, AF, and LVDP was significantly improved in all groups perfused with 5 mM of L-carnitine, acetyl-L-carnitine, and propionyl-L-carnitine. Significant postischemic ventricular recovery was noticed in the hearts perfused with 0.5 mM of propionyl-L-carnitine, but not with the same concentration of L-carnitine or L-acetyl carnitine. The incidence of reperfusion VF was reduced from its control value of 90 to 10% (p < 0.05) in hearts perfused with 5 mM of propionyl-L-carnitine only. Other doses of various carnitines failed to reduce the incidence of VF. The protection in CF, AF, LVDP, and VF reflected in a reduction in infarct size and apoptotic cell death in hearts treated with various concentrations of carnitine derivatives. The difference between effectiveness of various carnitines on the recovery of postischemic myocardium may be explained by different membrane permeability properties of carnitine and its derivatives.
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Affiliation(s)
- Jianhua Cui
- Cardiovascular Research Center, University of Connecticut School of Medicine, Farmington, CT 06030-1110, USA
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Iacobazzi V, Pasquali M, Singh R, Matern D, Rinaldo P, Amat di San Filippo C, Palmieri F, Longo N. Response to therapy in carnitine/acylcarnitine translocase (CACT) deficiency due to a novel missense mutation. Am J Med Genet A 2004; 126A:150-5. [PMID: 15057979 DOI: 10.1002/ajmg.a.20573] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Deficiency of carnitine/acylcarnitine translocase (CACT) is an autosomal recessive disorder of the carnitine cycle resulting in the inability to transfer fatty acids across the inner mitochondrial membrane. Only a limited number of affected patients have been reported and the effect of therapy on this condition is still not well defined. Here, we report a new patient with this disorder and follow the response to therapy. Our patient was the product of a consanguineous marriage. He presented shortly after birth with cardiac myopathy and arrhythmia coupled with severe non-ketotic hypoglycemia. Initial metabolic studies indicated severe non-ketotic C6-C10 dicarboxylic aciduria, plasma carnitine deficiency, and a characteristic elevation of plasma C:16:0, C18:1, and C18:2 acylcarnitine species. Enzyme assay confirmed deficiency of CACT activity. Molecular studies indicated that this child was homozygous, and both parents heterozygous, for a single bp change converting glutamine 238 to arginine (Q238R). Therapy with a formula providing most of the fat via medium chain triglycerides (MCT) and carnitine supplementation reduced the concentration of long-chain acylcarnitines and reversed cardiac symptoms and the hypoglycemia. These results suggest that carnitine and MCT may be effective in treating this defect of long-chain fatty acid oxidation.
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Affiliation(s)
- Vito Iacobazzi
- Dipartimento Farmaco-Biologico, University of Bari, Italy
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Mengi SA, Dhalla NS. Carnitine palmitoyltransferase-I, a new target for the treatment of heart failure: perspectives on a shift in myocardial metabolism as a therapeutic intervention. Am J Cardiovasc Drugs 2004; 4:201-9. [PMID: 15285695 DOI: 10.2165/00129784-200404040-00001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although the heart is capable of extracting energy from different types of substrates such as fatty acids and carbohydrates, fatty acids are the preferred fuel under physiological conditions. In view of the presence of diverse defects in myocardial metabolism in the failing heart, changes in metabolism of glucose and fatty acids are considered as viable targets for therapeutic modification in the treatment of heart failure. One of these changes involves the carnitine palmitoyltransferase (CPT) enzymes, which are required for the transfer of long chain fatty acids into the mitochondrial matrix for oxidation. Since CPT inhibitors have been shown to prevent the undesirable effects induced by mechanical overload, e.g. cardiac hypertrophy and heart failure, it was considered of interest to examine whether the inhibition of CPT enzymes represents a novel approach for the treatment of heart disease. A shift from fatty acid metabolism to glucose metabolism due to CPT-I inhibition has been reported to exert beneficial effects in both cardiac hypertrophy and heart failure. Since the inhibition of fatty acid oxidation is effective in controlling abnormalities in diabetes mellitus, CPT-I inhibitors may also prove useful in the treatment of diabetic cardiomyopathy. Accordingly, it is suggested that CPT-I may be a potential target for drug development for the therapy of heart disease in general and heart failure in particular.
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Affiliation(s)
- Sushma A Mengi
- Institute of Cardiovascular Sciences, University of Manitoba, St Boniface General Hospital Research Centre, Winnipeg, Manitoba, Canada
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Emura I, Usuda H. Morphological investigation of two sibling autopsy cases of mitochondrial trifunctional protein deficiency. Pathol Int 2003; 53:775-9. [PMID: 14629302 DOI: 10.1046/j.1440-1827.2003.01558.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two sibling autopsy cases of type 2 mitochondrial trifunctional protein (MTP) deficiency are described. MTP is an enzyme complex involved in the mitochondrial beta-oxidation of fatty acids, which is the major pathway for energy production in heart and skeletal muscle. Both cases showed similar pathological findings. Numerous small foci of degeneration of muscle cells and cardiac myocytes were detected. Some of these cells had condensed or fragmented nuclei and most of them were positively stained using the deoxyuridine triphosphate nick-end labeling method. The lipid staining of both cases showed a small- to medium-sized fatty, vesicular morphology for liver cells, muscle cells, cardiac myocytes and proximal tubular cells of the kidney. Bone marrow was severely hypoplastic, and cortical thymocytes were markedly reduced in number. Neither case had hepatic fibrosis nor cirrhosis. The definitive diagnosis of type 2 MTP deficiency was made by verifying completely defective MTP-alpha and MTP-beta subunits in cultured skin fibroblasts of one of 2 patients. Our patients' signs indicate that there is a wider pathological spectrum of type 2 MTP deficiency, while very few autopsy cases of type 2 MTP deficiency have been confirmed. Pathologists should consider the possibility of type 2 MTP deficiency or other beta-oxidation defects in cases of sudden infant death, fatty infiltration of viscera or cardiomyopathy.
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Affiliation(s)
- Iwao Emura
- Department of Surgical Pathology, Nagaoka Red Cross Hospital, Nagaoka, Japan.
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den Boer MEJ, Dionisi-Vici C, Chakrapani A, van Thuijl AOJ, Wanders RJA, Wijburg FA. Mitochondrial trifunctional protein deficiency: a severe fatty acid oxidation disorder with cardiac and neurologic involvement. J Pediatr 2003; 142:684-9. [PMID: 12838198 DOI: 10.1067/mpd.2003.231] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine the spectrum of presentation, including both clinical and biochemical abnormalities, and the clinical course in a cohort of patients with complete mitochondrial trifunctional protein (MTP) deficiency, a rare inborn error of mitochondrial fatty acid oxidation. STUDY DESIGN A questionnaire was sent to the referring physicians from 25 unselected MTP-deficient patients. RESULTS Twenty-one patients could be included. Questionnaires about four patients were not returned. Nine (43%) patients presented with rapidly progressive clinical deterioration; six (67%) of them had hypoketotic hypoglycemia. The remaining 12 patients presented with a much more insidious disease with nonspecific chronic symptoms, including hypotonia (100%), cardiomyopathy (73%), failure to thrive, or peripheral neuropathy. Ten patients (48%) presented in the neonatal period. Mortality was high (76%), mostly attributable to cardiac involvement. Two patients who were diagnosed prenatally died despite treatment. CONCLUSION Complete MTP deficiency often presents with nonspecific symptomatology, which makes clinical recognition difficult. Hypotonia and cardiomyopathy are common presenting features, and the differential diagnosis of an infant with these signs should include MTP deficiency. In spite of early diagnosis and treatment, only a few patients with this condition have survived.
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Affiliation(s)
- Margarethe E J den Boer
- Department of Pediatrics, Academic Medical Center, University of Amsterdam, The Netherlands.
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Atkinson LL, Kozak R, Kelly SE, Onay Besikci A, Russell JC, Lopaschuk GD. Potential mechanisms and consequences of cardiac triacylglycerol accumulation in insulin-resistant rats. Am J Physiol Endocrinol Metab 2003; 284:E923-30. [PMID: 12464581 DOI: 10.1152/ajpendo.00360.2002] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The accumulation of intracellular triacylglycerol (TG) is highly correlated with muscle insulin resistance. However, it is controversial whether the accumulation of TG is the result of increased fatty acid supply, decreased fatty acid oxidation, or both. Because abnormal fatty acid metabolism is a key contributor to the pathogenesis of diabetes-related cardiovascular dysfunction, we examined fatty acid and glucose metabolism in hearts of insulin-resistant JCR:LA-cp rats. Isolated working hearts from insulin-resistant rats had glycolytic rates that were reduced to 50% of lean control levels (P < 0.05). Cardiac TG content was increased by 50% (P < 0.05) in the insulin-resistant rats, but palmitate oxidation rates remained similar between the insulin-resistant and lean control rats. However, plasma fatty acids and TG levels, as well as cardiac fatty acid-binding protein (FABP) expression, were significantly increased in the insulin-resistant rats. AMP-activated protein kinase (AMPK) plays a major role in the regulation of cardiac fatty acid and glucose metabolism. When activated, AMPK increases fatty acid oxidation by inhibiting acetyl-CoA carboxylase (ACC) and reducing malonyl-CoA levels, and it decreases TG content by inhibiting glycerol-3-phosphate acyltransferase (GPAT), the rate-limiting step in TG synthesis. The activation of AMPK also stimulates cardiac glucose uptake and glycolysis. We thus investigated whether a decrease in AMPK activity was responsible for the reduced cardiac glycolysis and increased TG content in the insulin-resistant rats. However, we found no significant difference in AMPK activity. We also found no significant difference in various established downstream targets of AMPK: ACC activity, malonyl-CoA levels, carnitine palmitoyltransferase I activity, or GPAT activity. We conclude that hearts from insulin-resistant JCR:LA-cp rats accumulate substantial TG as a result of increased fatty acid supply rather than from reduced fatty acid oxidation. Furthermore, the accumulation of cardiac TG is associated with a reduction in insulin-stimulated glucose metabolism.
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Affiliation(s)
- Laura L Atkinson
- Cardiovascular Research Group, Department of Pediatrics, Faculty of Medicine, The University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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Liu SJ, Kennedy RH, Creer MH, McHowat J. Alterations in Ca2+ cycling by lysoplasmenylcholine in adult rabbit ventricular myocytes. Am J Physiol Cell Physiol 2003; 284:C826-38. [PMID: 12456398 DOI: 10.1152/ajpcell.00465.2002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We previously reported that lysoplasmenylcholine (LPlasC) altered the action potential (AP) and induced afterdepolarizations in rabbit ventricular myocytes. In this study, we investigated how LPlasC alters excitation-contraction coupling using edge-motion detection, fura-PE3 fluorescent indicator, and perforated and whole cell patch-clamp techniques. LPlasC increased contraction, myofilament Ca(2+) sensitivity, systolic and diastolic free Ca(2+) levels, and the magnitude of Ca(2+) transients concomitant with increases in the maximum rates of shortening and relaxation of contraction and the rising and declining phases of Ca(2+) transients. In some cells, LPlasC induced arrhythmias in a pattern consistent with early and delayed aftercontractions. LPlasC also augmented the caffeine-induced Ca(2+) transient with a reduction in the decay rate. Furthermore, LPlasC enhanced L-type Ca(2+) channel current (I(Ca,L)) and outward currents. LPlasC-induced alterations in contraction and I(Ca,L) were paralleled by its effect on the AP. Thus these results suggest that LPlasC elicits distinct, potent positive inotropic, lusitropic, and arrhythmogenic effects, resulting from increases in Ca(2+) influx, Ca(2+) sensitivity, sarcoplasmic reticular (SR) Ca(2+) release and uptake, SR Ca(2+) content, and probably reduction in sarcolemmal Na(+)/Ca(2+) exchange.
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Affiliation(s)
- Shi J Liu
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
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Abstract
Early-onset dilatative and/or hypertrophic cardiomyopathy with episodic hypoglycaemic coma and very low serum and tissue concentrations of carnitine should alert the clinician to the probability of the plasmalemmal high-affinity carnitine transporter defect. The diagnosis can be established by demonstration of impaired carnitine uptake in cultured skin fibroblasts or lymphoblasts and confirmed by mutation analysis of the human OCTN2 gene in the affected child and obligate heterozygote parents. The institution of high-dose oral carnitine supplementation reverses the pathology in this otherwise lethal autosomal recessive disease of childhood, and carnitine therapy from birth in prospectively screened siblings may altogether prevent the development of the clinical phenotype. Heterozygotes may be at risk for cardiomyopathy in later adult life, particularly in the presence of additional risk factors such as hypertension and competitive pharmacological agents. OCTN2 belongs to a family of organic cation/carnitine transporters that function primarily in the elimination of cationic drugs and other xenobiotics in kidney, intestine, liver and placenta. The high- and low-affinity human carnitine transporters, OCTN2 and OCTN1, are multifunctional polyspecific organic cation transporters; therefore, defects in these transporters may have widespread implications for the absorption and/or elimination of a number of key pharmacological agents such as cephalosporins, verapamil, quinidine and valproic acid. A third organic/cation carnitine transporter with high specificity for carnitine, Octn3, has been cloned in mice. The juvenile visceral steatosis (jvs) mouse serves as an excellent clinical, biochemical and molecular model for the high-affinity carnitine transporter OCTN2 defect and is due to a spontaneous point mutation in the murine Octn2 gene on mouse chromosome 11, which is syntenic to the human locus at 5q31 that harbours the human OCTN2 gene.
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Affiliation(s)
- I Tein
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada.
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Drug Development Based on Functional Genomics of Overloaded Cardiomyocytes: CPT 1 vs. PPARalpha Effects of Etomoxir. PROGRESS IN EXPERIMENTAL CARDIOLOGY 2003. [DOI: 10.1007/978-1-4615-0455-9_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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