1
|
Yan Y, Smith E, Melander O, Ottosson F. The association between plasma metabolites and future risk of all-cause mortality. J Intern Med 2022; 292:804-815. [PMID: 35796403 PMCID: PMC9796397 DOI: 10.1111/joim.13540] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Metabolite profiles provide snapshots of the overall effect of numerous exposures accumulated over life courses, which may lead to health outcomes in the future. OBJECTIVE We hypothesized that the risk of all-cause mortality is linked to alterations in metabolism earlier in life, which are reflected in plasma metabolite profiles. We aimed to identify plasma metabolites associated with future risk of all-cause mortality. METHODS Through metabolomics, 110 metabolites were measured in 3833 individuals from the Malmö Diet and Cancer-Cardiovascular Cohort (MDC-CC). A total of 1574 deaths occurred within an average follow-up time of 22.2 years. Metabolites that were significantly associated with all-cause mortality in MDC-CC were replicated in 1500 individuals from Malmö Preventive Project re-examination (MPP), among whom 715 deaths occurred within an average follow-up time of 11.3 years. RESULTS Twenty two metabolites were significantly associated with all-cause mortality in MDC-CC, of which 13 were replicated in MPP. Levels of trigonelline, glutamate, dimethylglycine, C18-1-carnitine, C16-1-carnitine, C14-1-carnitine, and 1-methyladenosine were associated with an increased risk, while levels of valine, tryptophan, lysine, leucine, histidine, and 2-aminoisobutyrate were associated with a decreased risk of all-cause mortality. CONCLUSION We used metabolomics in two Swedish prospective cohorts and identified replicable associations between 13 metabolites and future risk of all-cause mortality. Novel associations between five metabolites-C18-1-carnitine, C16-1-carnitine, C14-1-carnitine, trigonelline, and 2-aminoisobutyrate-and all-cause mortality were discovered. These findings suggest potential new biomarkers for the prediction of mortality and provide insights for understanding the biochemical pathways that lead to mortality.
Collapse
Affiliation(s)
- Yingxiao Yan
- Department of Clinical Science, Lund University, Malmö, Sweden.,Department of Biology and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Einar Smith
- Department of Clinical Science, Lund University, Malmö, Sweden
| | - Olle Melander
- Department of Clinical Science, Lund University, Malmö, Sweden
| | - Filip Ottosson
- Department of Clinical Science, Lund University, Malmö, Sweden.,Section for Clinical Mass Spectrometry, Danish Center for Neonatal Screening, Department of Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| |
Collapse
|
2
|
Lu C, Liu C, Mei D, Yu M, Bai J, Bao X, Wang M, Fu K, Yi X, Ge W, Shen J, Peng Y, Xu W. Comprehensive metabolomic characterization of atrial fibrillation. Front Cardiovasc Med 2022; 9:911845. [PMID: 36003904 PMCID: PMC9393302 DOI: 10.3389/fcvm.2022.911845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundUsing human humoral metabolomic profiling, we can discover the diagnostic biomarkers and pathogenesis of disease. The specific characterization of atrial fibrillation (AF) subtypes with metabolomics may facilitate effective and targeted treatment, especially in early stages.ObjectivesBy investigating disturbed metabolic pathways, we could evaluate the diagnostic value of biomarkers based on metabolomics for different types of AF.MethodsA cohort of 363 patients was enrolled and divided into a discovery and validation set. Patients underwent an electrocardiogram (ECG) for suspected AF. Groups were divided as follows: healthy individuals (Control), suspected AF (Sus-AF), first diagnosed AF (Fir-AF), paroxysmal AF (Par-AF), persistent AF (Per-AF), and AF causing a cardiogenic ischemic stroke (Car-AF). Serum metabolomic profiles were determined by gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Metabolomic variables were analyzed with clinical information to identify relevant diagnostic biomarkers.ResultsThe metabolic disorders were characterized by 16 cross-comparisons. We focused on comparing all of the types of AF (All-AFs) plus Car-AF vs. Control, All-AFs vs. Car-AF, Par-AF vs. Control, and Par-AF vs. Per-AF. Then, 117 and 94 metabolites were identified by GC/MS and LC-QTOF-MS, respectively. The essential altered metabolic pathways during AF progression included D-glutamine and D-glutamate metabolism, glycerophospholipid metabolism, etc. For differential diagnosis, the area under the curve (AUC) of specific metabolomic biomarkers ranged from 0.8237 to 0.9890 during the discovery phase, and the predictive values in the validation cohort were 78.8–90.2%.ConclusionsSerum metabolomics is a powerful way to identify metabolic disturbances. Differences in small–molecule metabolites may serve as biomarkers for AF onset, progression, and differential diagnosis.
Collapse
|
3
|
Aitken-Buck HM, Krause J, van Hout I, Davis PJ, Bunton RW, Parry DJ, Williams MJA, Coffey S, Zeller T, Jones PP, Lamberts RR. Long-chain acylcarnitine 18:1 acutely increases human atrial myocardial contractility and arrhythmia susceptibility. Am J Physiol Heart Circ Physiol 2021; 321:H162-H174. [PMID: 34085842 DOI: 10.1152/ajpheart.00184.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Long-chain acylcarnitines (LCACs) are known to directly alter cardiac contractility and electrophysiology. However, the acute effect of LCACs on human cardiac function is unknown. We aimed to determine the effect of LCAC 18:1, which has been associated with cardiovascular disease, on the contractility and arrhythmia susceptibility of human atrial myocardium. Additionally, we aimed to assess how LCAC 18:1 alters Ca2+ influx and spontaneous Ca2+ release in vitro. Human right atrial trabeculae (n = 32) stimulated at 1 Hz were treated with LCAC 18:1 at a range of concentrations (1-25 µM) for a 45-min period. Exposure to the LCAC induced a dose-dependent positive inotropic effect on myocardial contractility (maximal 1.5-fold increase vs. control). At the 25 µM dose (n = 8), this was paralleled by an enhanced propensity for spontaneous contractions (50% increase). Furthermore, all LCAC 18:1 effects on myocardial function were reversed following LCAC 18:1 washout. In fluo-4-AM-loaded HEK293 cells, LCAC 18:1 dose dependently increased cytosolic Ca2+ influx relative to vehicle controls and the short-chain acylcarnitine C3. In HEK293 cells expressing ryanodine receptor (RyR2), this increased Ca2+ influx was linked to an increased propensity for RyR2-mediated spontaneous Ca2+ release events. Our study is the first to show that LCAC 18:1 directly and acutely alters human myocardial function and in vitro Ca2+ handling. The metabolite promotes proarrhythmic muscle contractions and increases contractility. The exploratory findings in vitro suggest that LCAC 18:1 increases proarrhythmic RyR2-mediated spontaneous Ca2+ release propensity. The direct effects of metabolites on human myocardial function are essential to understand cardiometabolic dysfunction.NEW & NOTEWORTHY For the first time, the fatty acid metabolite, long-chain acylcarnitine 18:1, is shown to acutely increase the arrhythmia susceptibility and contractility of human atrial myocardium. In vitro, this was linked to an influx of Ca2+ and an enhanced propensity for spontaneous RyR2-mediated Ca2+ release.
Collapse
Affiliation(s)
- Hamish M Aitken-Buck
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Julia Krause
- University Heart and Vascular Centre, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Isabelle van Hout
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Otago Medical School-Dunedin Campus, Dunedin Hospital, Dunedin, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Otago Medical School-Dunedin Campus, Dunedin Hospital, Dunedin, New Zealand
| | - Dominic J Parry
- Department of Cardiothoracic Surgery, Otago Medical School-Dunedin Campus, Dunedin Hospital, Dunedin, New Zealand
| | - Michael J A Williams
- Department of Medicine, Heart Otago, Otago Medical School-Dunedin Campus, University of Otago, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine, Heart Otago, Otago Medical School-Dunedin Campus, University of Otago, Dunedin, New Zealand
| | - Tanja Zeller
- University Heart and Vascular Centre, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Peter P Jones
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| |
Collapse
|
4
|
Li MY, Chen HX, Hou HT, Wang J, Liu XC, Yang Q, He GW. Biomarkers and key pathways in atrial fibrillation associated with mitral valve disease identified by multi-omics study. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:393. [PMID: 33842614 PMCID: PMC8033373 DOI: 10.21037/atm-20-3767] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Mitral valve disease (MVD)-associated atrial fibrillation (AF) is one of the most common arrhythmias with an increased risk of thromboembolic events. This study aimed to identify the molecular mechanisms and possible biomarkers for chronic AF in MVD by using multi-omics methods. Methods This prospective study enrolled patients with MVD (n=100) undergoing mitral valve replacement surgery. The patients were allocated into chronic AF and sinus rhythm (SR) groups. Plasma samples were collected preoperatively. Proteomics was performed with isobaric tags for relative and absolute quantitation (iTRAQ) to identify differential proteins (DPs) between the two groups. The selected DPs were then validated in a new cohort of patients by enzyme-linked immunosorbent assay (ELISA). A gas chromatography-mass spectrometer was used in the metabolomics study to identify differential metabolites (DMs). Bioinformatics analyses were performed to analyze the results. Results Among the 447 plasma proteins and 322 metabolites detected, 57 proteins and 55 metabolites, including apolipoprotein A-I (ApoA-I), apolipoprotein A-II (ApoA-II), LIM domain only protein 7 (LMO7), and vitronectin (VN) were differentially expressed between AF and SR patients. Bioinformatics analyses identified enriched pathways related to AF, including peroxisome proliferator-activated receptor alpha (PPARα), the renin angiotensin aldosterone system (RAAS), galactose, biosynthesis of unsaturated fatty acids, and linoleic acid metabolism. Conclusions Using integrated multi-omics technologies in MVD-associated AF patients, the present study, for the first time, revealed important signaling pathways, such as PPARα, as well as possible roles of other signaling pathways, including the RAAS and galactose metabolism to understand the molecular mechanism of MVD-associated AF. It also identified a large number of DPs and DMs. Some identified proteins and metabolites, such as ApoA-I, ApoA-II, LMO7, and VN, may be further developed as biomarkers for MVD-associated AF.
Collapse
Affiliation(s)
- Ming-Yang Li
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Huan-Xin Chen
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Hai-Tao Hou
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Jun Wang
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Xiao-Cheng Liu
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Qin Yang
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China
| | - Guo-Wei He
- Center for Basic Medical Research & Department of Cardiovascular Surgery, TEDA International Cardiovascular Hospital, Chinese Academy of Medical Sciences & Graduate School, Peking Union Medical College, Beijing, China.,The Institute of Cardiovascular Diseases, Tianjin University, Tianjin, China.,Drug Research and Development Center, Wannan Medical College, Wuhu, China.,Department of Surgery, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
5
|
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: 4] [Impact Index Per Article: 1.3] [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.
Collapse
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
| |
Collapse
|
6
|
Smith E, Fernandez C, Melander O, Ottosson F. Altered Acylcarnitine Metabolism Is Associated With an Increased Risk of Atrial Fibrillation. J Am Heart Assoc 2020; 9:e016737. [PMID: 33076748 PMCID: PMC7763428 DOI: 10.1161/jaha.120.016737] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Atrial fibrillation (AF) is the most common cardiac arrhythmia, but the pathogenesis is not completely understood. The application of metabolomics could help in discovering new metabolic pathways involved in the development of the disease. Methods and Results We measured 112 baseline fasting metabolites of 3770 participants in the Malmö Diet and Cancer Study; these participants were free of prevalent AF. Incident cases of AF were ascertained through previously validated registers. The associations between baseline levels of metabolites and incident AF were investigated using Cox proportional hazard models. During 23.1 years of follow-up, 650 cases of AF were identified (incidence rate: 8.6 per 1000 person-years). In Cox regression models adjusted for AF risk factors, 7 medium- and long-chain acylcarnitines were associated with higher risk of incident AF (hazard ratio [HR] ranging from 1.09; 95% CI, 1.00-1.18 to 1.14, 95% CI, 1.05-1.24 per 1 SD increment of acylcarnitines). Furthermore, caffeine and acisoga were also associated with an increased risk (HR, 1.17; 95% CI, 1.06-1.28 and 1.08; 95% CI, 1.00-1.18, respectively), while beta carotene was associated with a lower risk (HR, 0.90; 95% CI, 0.82-0.99). Conclusions For the first time, we show associations between altered acylcarnitine metabolism and incident AF independent of traditional AF risk factors in a general population. These findings highlight metabolic alterations that precede AF diagnosis by many years and could provide insight into the pathogenesis of AF. Future studies are needed to replicate our finding in an external cohort as well as to test whether the relationship between acylcarnitines and AF is causal.
Collapse
Affiliation(s)
- Einar Smith
- Department of Clinical Sciences Lund University Malmö Sweden
| | | | - Olle Melander
- Department of Clinical Sciences Lund University Malmö Sweden.,Department of Internal Medicine Skåne University Hospital Malmö Sweden
| | - Filip Ottosson
- Department of Clinical Sciences Lund University Malmö Sweden
| |
Collapse
|
7
|
Wanders RJA, Visser G, Ferdinandusse S, Vaz FM, Houtkooper RH. Mitochondrial Fatty Acid Oxidation Disorders: Laboratory Diagnosis, Pathogenesis, and the Complicated Route to Treatment. J Lipid Atheroscler 2020; 9:313-333. [PMID: 33024728 PMCID: PMC7521971 DOI: 10.12997/jla.2020.9.3.313] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial fatty acid (FA) oxidation deficiencies represent a genetically heterogeneous group of diseases in humans caused by defects in mitochondrial FA beta-oxidation (mFAO). A general characteristic of all mFAO disorders is hypoketotic hypoglycemia resulting from the enhanced reliance on glucose oxidation and the inability to synthesize ketone bodies from FAs. Patients with a defect in the oxidation of long-chain FAs are at risk to develop cardiac and skeletal muscle abnormalities including cardiomyopathy and arrhythmias, which may progress into early death, as well as rhabdomyolysis and exercise intolerance. The diagnosis of mFAO-deficient patients has greatly been helped by revolutionary developments in the field of tandem mass spectrometry (MS) for the analysis of acylcarnitines in blood and/or urine of candidate patients. Indeed, acylcarnitines have turned out to be excellent biomarkers; not only do they provide information whether a certain patient is affected by a mFAO deficiency, but the acylcarnitine profile itself usually immediately points to which enzyme is likely deficient. Another important aspect of acylcarnitine analysis by tandem MS is that this technique allows high-throughput analysis, which explains why screening for mFAO deficiencies has now been introduced in many newborn screening programs worldwide. In this review, we will describe the current state of knowledge about mFAO deficiencies, with particular emphasis on recent developments in the area of pathophysiology and treatment.
Collapse
Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Gepke Visser
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands.,Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Riekelt H Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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.)
| |
Collapse
|
10
|
Baumeister P, Quinn TA. Altered Calcium Handling and Ventricular Arrhythmias in Acute Ischemia. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2016; 10:61-69. [PMID: 28008297 PMCID: PMC5158122 DOI: 10.4137/cmc.s39706] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/27/2016] [Accepted: 11/20/2016] [Indexed: 12/14/2022]
Abstract
Acute ischemia results in deadly cardiac arrhythmias that are a major contributor to sudden cardiac death (SCD). The electrophysiological changes involved have been extensively studied, yet the mechanisms of ventricular arrhythmias during acute ischemia remain unclear. What is known is that during acute ischemia both focal (ectopic excitation) and nonfocal (reentry) arrhythmias occur, due to an interaction of altered electrical, mechanical, and biochemical properties of the myocardium. There is particular interest in the role that alterations in intracellular calcium handling, which cause changes in intracellular calcium concentration and to the calcium transient, play in ischemia-induced arrhythmias. In this review, we briefly summarize the known contributors to ventricular arrhythmias during acute ischemia, followed by an in-depth examination of the potential contribution of altered intracellular calcium handling, which may include novel targets for antiarrhythmic therapy.
Collapse
Affiliation(s)
- Peter Baumeister
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| |
Collapse
|
11
|
Devanathan S, Whitehead TD, Fettig N, Gropler RJ, Nemanich S, Shoghi KI. Sexual dimorphism in myocardial acylcarnitine and triglyceride metabolism. Biol Sex Differ 2016; 7:25. [PMID: 27182432 PMCID: PMC4866274 DOI: 10.1186/s13293-016-0077-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/24/2016] [Indexed: 01/22/2023] Open
Abstract
Background Cardiovascular disease is the leading cause of death among diabetic patients. Importantly, recent data highlight the apparent sexual dimorphism in the pathogenesis of cardiovascular disease in diabetics with respect to both frequency- and age-related risk factors. The disposition to cardiovascular disease among diabetic patients has been attributed, at least in part, to excess lipid supply to the heart culminating in lipotoxicity of the heart and downstream derangements. A confounding factor in obese animal models of diabetes is that increased peripheral lipid availability to the heart can induce cardio-metabolic remodeling independent of the underlying pathophysiology of diabetes, thus masking the diabetic phenotype. To that end, we hypothesized that the use of non-obese diabetic (NOD) animal models will reveal metabolic signatures of diabetes in a sex-specific manner. Methods To test this hypothesis, male and female NOD Goto-Kakizaki (GK) rats were used to assess the expression profile of 84 genes involved in lipid metabolism. In parallel, targeted lipidomics analysis was performed to characterize sex differences in homeostasis of non-esterified fatty acids (NEFA), acylcarnitines (AC), and triglycerides (TG). Results Our analysis revealed significant sex differences in the expression of a broad range of genes involved in transport, activation, and utilization of lipids. Furthermore, NOD male rats exhibited enhanced oxidative metabolism and accumulation of TG, whereas female NOD rats exhibited reduced TG content coupled with accumulation of AC species. Multi-dimensional statistical analysis identified saturated AC16:0, AC18:0, and AC20:0 as dominant metabolites in mediating sex differences in AC metabolism. Confocal microscopy of rat cardiomyocytes exposed to AC14:0, AC16:0, and AC18:0 confirmed induction of ROS with AC18:0 being more potent followed by AC14:0. Conclusion Overall, we demonstrate sex differences in myocardial AC and TG metabolism with implications for therapy and diagnosis of diabetic cardiovascular disease. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0077-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sriram Devanathan
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Timothy D Whitehead
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Nicole Fettig
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Robert J Gropler
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Department of Medicine, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Samuel Nemanich
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| | - Kooresh I Shoghi
- Department of Radiology, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Department of Biomedical Engineering, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA.,Division of Biology and Biomedical Sciences, Washington University in St. Louis, 510 South Kingshighway Blvd., Campus Box 8225, Saint Louis, MO 63110 USA
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Bala P, Ferdinandusse S, Olpin SE, Chetcuti P, Morris AAM. Recurrent Ventricular Tachycardia in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency. JIMD Rep 2015; 27:11-5. [PMID: 26404458 DOI: 10.1007/8904_2015_463] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 05/12/2015] [Accepted: 05/17/2015] [Indexed: 12/25/2022] Open
Abstract
We report a baby with medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency who presented on day 2 with poor feeding and lethargy. She was floppy with hypoglycaemia (1.8 mmol/l) and hyperammonaemia (182 μmol/l). Despite correction of these and a continuous intravenous infusion of glucose at 4.5-6.2 mg/kg/min, she developed generalised tonic clonic seizures on day 3. She also suffered two episodes of pulseless ventricular tachycardia, from which she was resuscitated successfully. Unfortunately, she died on day 5, following a third episode of pulseless ventricular tachycardia. Arrhythmias are generally thought to be rarer in MCAD deficiency than in disorders of long-chain fatty acid oxidation. This is, however, the sixth report of ventricular tachyarrhythmias in MCAD deficiency. Five of these involved neonates and it may be that patients with MCAD deficiency are particularly prone to ventricular arrhythmias in the newborn period. Three of the patients (including ours) had normal blood glucose concentrations at the time of the arrhythmias and had been receiving intravenous glucose for many hours. These cases suggest that arrhythmias can be induced by medium-chain acylcarnitines or other metabolites accumulating in MCAD deficiency. Ventricular tachyarrhythmias can occur in MCAD deficiency, especially in neonates.
Collapse
Affiliation(s)
- P Bala
- Department of Paediatrics, Airedale General Hospital, Keighley, UK
| | - S Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - S E Olpin
- Department of Clinical Chemistry, Sheffield Children's Hospital, Sheffield, UK
| | - P Chetcuti
- Department of Paediatrics, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - A A M Morris
- Willink Unit, Manchester Centre for Genomic Medicine, St Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK.
| |
Collapse
|
14
|
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: 47] [Impact Index Per Article: 5.2] [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.
Collapse
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
| |
Collapse
|
15
|
Soni MS, Rabaglia ME, Bhatnagar S, Shang J, Ilkayeva O, Mynatt R, Zhou YP, Schadt EE, Thornberry NA, Muoio DM, Keller MP, Attie AD. Downregulation of carnitine acyl-carnitine translocase by miRNAs 132 and 212 amplifies glucose-stimulated insulin secretion. Diabetes 2014; 63:3805-14. [PMID: 24969106 PMCID: PMC4207388 DOI: 10.2337/db13-1677] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We previously demonstrated that micro-RNAs (miRNAs) 132 and 212 are differentially upregulated in response to obesity in two mouse strains that differ in their susceptibility to obesity-induced diabetes. Here we show the overexpression of miRNAs 132 and 212 enhances insulin secretion (IS) in response to glucose and other secretagogues including nonfuel stimuli. We determined that carnitine acyl-carnitine translocase (CACT; Slc25a20) is a direct target of these miRNAs. CACT is responsible for transporting long-chain acyl-carnitines into the mitochondria for β-oxidation. Small interfering RNA-mediated knockdown of CACT in β-cells led to the accumulation of fatty acyl-carnitines and enhanced IS. The addition of long-chain fatty acyl-carnitines promoted IS from rat insulinoma β-cells (INS-1) as well as primary mouse islets. The effect on INS-1 cells was augmented in response to suppression of CACT. A nonhydrolyzable ether analog of palmitoyl-carnitine stimulated IS, showing that β-oxidation of palmitoyl-carnitine is not required for its stimulation of IS. These studies establish a link between miRNA-dependent regulation of CACT and fatty acyl-carnitine-mediated regulation of IS.
Collapse
Affiliation(s)
- Mufaddal S Soni
- Department of Biochemistry, University of Wisconsin, Madison, WI
| | - Mary E Rabaglia
- Department of Biochemistry, University of Wisconsin, Madison, WI
| | | | - Jin Shang
- Department of Metabolic Disorders-Diabetes, Merck Research Laboratories, Rahway, NJ
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center, Department of Medicine, Duke University, Durham, NC
| | - Randall Mynatt
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA
| | - Yun-Ping Zhou
- Department of Metabolic Disorders-Diabetes, Merck Research Laboratories, Rahway, NJ
| | - Eric E Schadt
- Institute for Genomics and Multiscale Biology, Mount Sinai School of Medicine, New York, NY
| | - Nancy A Thornberry
- Department of Metabolic Disorders-Diabetes, Merck Research Laboratories, Rahway, NJ
| | - Deborah M Muoio
- Sarah W. Stedman Nutrition and Metabolism Center, Department of Medicine, Duke University, Durham, NC Departments of Medicine and Pharmacology and Cancer Biology, Duke University, Durham, NC
| | - Mark P Keller
- Department of Biochemistry, University of Wisconsin, Madison, WI
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin, Madison, WI
| |
Collapse
|
16
|
Ferro F, Ouillé A, Tran TA, Fontanaud P, Bois P, Babuty D, Labarthe F, Le Guennec JY. Long-chain acylcarnitines regulate the hERG channel. PLoS One 2012; 7:e41686. [PMID: 22848566 PMCID: PMC3404973 DOI: 10.1371/journal.pone.0041686] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 06/25/2012] [Indexed: 12/30/2022] Open
Abstract
Background and purpose In some pathological conditions carnitine concentration is high while in othersitis low.In bothcases,cardiac arrhythmiascan occur and lead to sudden cardiac death. It has been proposed that in ischaemia, acylcarnitine (acyl-CAR), but not carnitine, is involved in arrhythmiasthrough modulation of ionic currents. We studied the effects of acyl-CARs on hERG, KIR2.1 and Kv7.1/minKchannels (channels responsible for IKR, IK1 and IKS respectively). Experimental approach HEK293 cells stably expressing hERG, KIR2.1 or Kv7.1/minK were studied using the patch clamp technique. Free carnitine (CAR) and acyl-CAR derivatives from medium- (C8 and C10) and long-chain (C16 and C18∶1) fatty acids were applied intra- and extracellularly at different concentrations. Forstudies onhERG, C16 and C18∶1 free fatty acid were also used. Key results Extracellular long-chain (LCAC), but not medium-chain, acyl-CAR,induced an increase of IhERG amplitude associated with a dose-dependent speeding of deactivation kinetics. They had no effect on KIR2.1 or Kv7.1/minK currents.Computer simulations of these effects wereconsistent with changes in action potential profile. Conclusions and applications Extracellular LCAC tonically regulates IhERG amplitude and kineticsunder physiological conditions. This modulation maycontribute tothe changes in action potential duration thatprecede cardiac arrhythmias in ischaemia, diabetes and primary systemic carnitine deficiency.
Collapse
Affiliation(s)
- Fabio Ferro
- INSERM U921, Université François-Rabelais, Tours, France
| | - Aude Ouillé
- INSERM U1046, Université Montpellier-1, Université Montpellier-2, Montpellier, France
- * E-mail:
| | - Truong-An Tran
- INSERM U921, Université François-Rabelais, Tours, France
| | - Pierre Fontanaud
- IGF-CNRS INSERM 661, Université Montpellier-1, Université Montpellier-2, Montpellier, France
| | - Patrick Bois
- IPBC, UMR 6187, CNRS, Université de Poitiers, Poitiers, France
| | - Dominique Babuty
- CHRU Tours, Hôpital Trousseau, Service de cardiologie B, Tours, France
| | | | - Jean-Yves Le Guennec
- INSERM U1046, Université Montpellier-1, Université Montpellier-2, Montpellier, France
| |
Collapse
|
17
|
Hogue CW, Palin CA, Kailasam R, Lawton JS, Nassief A, Dávila-Román VG, Thomas B, Damiano R. C-reactive protein levels and atrial fibrillation after cardiac surgery in women. Ann Thorac Surg 2006; 82:97-102. [PMID: 16798197 PMCID: PMC1780029 DOI: 10.1016/j.athoracsur.2006.02.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2005] [Revised: 02/13/2006] [Accepted: 02/22/2006] [Indexed: 01/13/2023]
Abstract
BACKGROUND The aim of this study was to evaluate whether risk for postoperative atrial fibrillation in women is related to preexisting inflammation as detected by plasma C-reactive protein (CRP) concentrations. We further sought to assess the importance of atrial fibrillation for outcome after cardiac surgery in women. METHODS The CRP was measured before coronary artery bypass grafting and (or) valvular surgery using cardiopulmonary bypass in 141 women. Univariate and multivariate analyses were used to evaluate for differences in CRP levels between women with and without atrial fibrillation, and to assess for the importance of the arrhythmia and postoperative outcomes. RESULTS Atrial fibrillation developed in 46 (33%) women. Neither CRP concentrations (median +/- standard error, 13.3 +/- 2.5 mg/L vs 11.7 +/- 1.4 mg/L, p = 0.847), nor the frequency of elevated levels (defined as > upper 95% confidence interval or >19.2 mg/L) (19% vs 21%, p = 0.807) differed between women with or without atrial fibrillation. Patient age and previous stroke, but not CRP levels, were independently associated with atrial fibrillation. Women with atrial fibrillation were more likely to have low cardiac output syndrome (p = 0.018), stroke (p = 0.031), longer duration of hospitalization in the intensive care unit (p = 0.012) and on the postoperative (p = 0.0008) ward, and they were more likely to require an extended care facility after surgery (p = 0.046). CONCLUSIONS In contrast to findings from studies that have included mostly men, preoperative CRP concentrations are not associated with risk for atrial fibrillation after cardiac surgery for women. Postoperative atrial fibrillation in women is associated with increased risk for stroke, longer hospitalization, and extended care facility admission.
Collapse
Affiliation(s)
- Charles W Hogue
- Department of Anesthesiology, and Washington University School of Medicine, St. Louis, Missouri, USA.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Sperelakis N, Sunagawa M, Yokoshiki H, Seki T, Nakamura M. Regulation of ion channels in myocardial cells and protection of ischemic myocardium. Heart Fail Rev 2005; 5:139-66. [PMID: 16228141 DOI: 10.1023/a:1009832804103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- N Sperelakis
- Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0576, USA
| | | | | | | | | |
Collapse
|
19
|
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.
Collapse
Affiliation(s)
- Shi J Liu
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
| | | | | | | |
Collapse
|
20
|
Ziolo MT, Sondgeroth KL, Harshbarger CH, Smith JM, Wahler GM. Effects of arrhythmogenic lipid metabolites on the L-type calcium current of diabetic vs. non-diabetic rat hearts. Mol Cell Biochem 2001; 220:169-75. [PMID: 11451378 DOI: 10.1023/a:1010992900387] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Accumulation of lipid metabolites, such as palmitoylcarnitine and lysophosphatidylcholine, is thought to be a major contributor to the development of cardiac arrhythmias during myocardial ischemia. This arrhythmogenicity is likely due to the effects of these metabolites on various ion channels. Diabetic hearts have been shown to accumulate much higher concentrations of these lipid metabolites during ischemia, which may be an important factor in the enhanced incidence of arrhythmias in diabetic hearts. However, it is not known whether these metabolites have similar effects on the ion channels of diabetic hearts as in non-diabetic hearts. Previous studies on myocytes from non-diabetic hearts have reported either enhancement or inhibition of L-type calcium current (I(Ca)) by these lipid metabolites. Thus, it is not clear whether the effects of palmitoylcarnitine and/or lysophosphatidlycholine on I(Ca) contribute to the enhanced arrhythmogenicity of diabetic hearts or protect against arrhythmias. We determined the effect of exogenous palmitoylcarnitine and lysophosphatidylcholine on the (I(Ca)) in ventricular myocytes from streptozotocin-diabetic and non-diabetic rat hearts under identical conditions. We found that palmitoylcarnitine and lysophosphatidylcholine exhibited a dose-dependent inhibition of I(Ca), which was virtually identical in diabetic and non-diabetic cardiac myocytes. Thus, we conclude that these arrhythmogenic lipid metabolites have similar actions on calcium channels in diabetic and non-diabetic hearts. Therefore, the greater susceptibility of diabetic hearts to arrhythmias during myocardial ischemia is not due to an altered sensitivity of the L-type calcium channels to lipid metabolites, but may be explained, in large part, by the greater accumulation of these metabolites during ischemia.
Collapse
Affiliation(s)
- M T Ziolo
- Department of Physiology, Midwestern University, Downers Grove, IL 60515, USA
| | | | | | | | | |
Collapse
|
21
|
El-Aroussy W, Rizk A, Mayhoub G, Aleem SA, El-Tobgy S, Mokhtar MS. Plasma carnitine levels as a marker of impaired left ventricular functions. Mol Cell Biochem 2000; 213:37-41. [PMID: 11129956 DOI: 10.1023/a:1007142919941] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
L-Carnitine plays a role in the utilization of fatty acids and glucose in the myocardium. Previous studies have indicated carnitine deficiency in patients with congestive heart failure. However, the extent of altered carnitine metabolism and left ventricular function is not fully determined. This study is designed to determine if plasma L-carnitine levels can serve as a marker for impaired left ventricular function in patients with congestive heart failure. To test this hypothesis, plasma and urinary levels of L-carnitine were measured in 30 patients with congestive heart failure (CHF) and in 10 control subjects. CHF was due to dilated cardiomyopathy (DCM) and rheumatic heart disease (RHD). Cardiac functions such as percentage of fractional shortening (%FS), ejection fraction (EF), left ventricular mass index (LVMI), were determined by echocardiography. All patients and control subjects had normal renal functions. Plasma carnitine was significantly higher in patients with DCM (37.05+/-7.62, p < 0.0001) and with RHD (47.2+/-8.04, p < 0.0001) vs. the control subjects (14.4+/-5.30 mg/L). Urinary carnitine was significantly higher in DCM (49.13+/-14.11, p < 0.0001) and in RHD 43.53+/-15.5, p < 0.0001), than the control (25.1+/-5.78 mg/L). Plasma carnitine level correlated significantly with impaired left ventricular systolic functions in these patients: % FS < 25 % (r = -0.38 and p = 0.038), EF < 0.55 (r = -0.502 and p = 0.005) and LMVI > 124 gm/m2 (r = 0.436, and p = 0.016). These data suggest that elevated plasma and urinary carnitine levels in patients with CHF could serve as a marker for myocardial damage and impaired left ventricular functions.
Collapse
Affiliation(s)
- W El-Aroussy
- Department of Cardiology, Cairo University, Egypt
| | | | | | | | | | | |
Collapse
|
22
|
Sperelakis N, Katsube Y, Yokoshiki H, Sada H, Sumii K. Regulation of the slow Ca++ channels of myocardial cells. Mol Cell Biochem 1996; 163-164:85-98. [PMID: 8974043 DOI: 10.1007/bf00408644] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Contraction of the heart is regulated by a number of mechanisms, such as neurotransmitters, hormones, autacoids, pH, intracellular ATP, and Ca++ ions. These actions are mediated, at least in part, by actions on the sarcolemmal slow (L-type) Ca++ channels, exerted directly or indirectly. The major mechanisms for the regulation of the slow Ca++ channels of myocardial cells includes the following. cAMP/PK-A phosphorylation stimulates the slow Ca++ channel activity, whereas cGMP/PK-G phosphorylation inhibits. DAG/PK-C phosphorylation and tyrosine kinase phosphorylation are suggested to stimulate the slow Ca++ channel activity. Intracellular application of Gs alpha protein increases the slow Ca++ currents (ICa(L)). Lowering of intracellular ATP inhibits ICa(L). Acidosis and increase in [Ca]i inhibits ICa(L). A number of changes in the Ca++ channels also occur during development and aging. Thus, it appears that the slow Ca++ channel is a complex structure, including perhaps several associated regulatory proteins, which can be regulated by a number of extrinsic and intrinsic factors, and thereby control can be exercised over the force of contraction of the heart.
Collapse
|
23
|
Dumonteil E, Barré H, Meissner G. Effects of palmitoyl carnitine and related metabolites on the avian Ca(2+)-ATPase and Ca2+ release channel. J Physiol 1994; 479 ( Pt 1):29-39. [PMID: 7990033 PMCID: PMC1155723 DOI: 10.1113/jphysiol.1994.sp020275] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
1. In birds, prolonged cold exposure induces the development of a non-shivering thermogenesis (NST) of muscular origin that may result from an increase in ATP-dependent cycling of Ca2+ between the sarcoplasmic reticulum (SR) and the cytosol. 2. Because fatty acids are thought to play a significant role in NST, we investigated the effects of palmitic acid and related metabolites on skeletal SR Ca2+ uptake and release in ducklings. 3. Ca(2+)-ATPase activity, 45Ca2+ release and [3H]ryanodine-binding measurements indicated that palmitic acid was without effect on the Ca(2+)-ATPase and Ca2+ release channel. Palmitoyl carnitine and palmitoyl coenzyme A inhibited the Ca(2+)-ATPase at concentrations > 20 microM whereas both activated the Ca2+ release channel at concentrations < or = 20 microM in a dose-dependent manner. 4. Palmitoyl carnitine stimulated [3H]ryanodine binding to skeletal but not cardiac SR vesicles. Induction of 45Ca2+ release was observed with long-chain (C > or = 14) but not with short-chain acyl carnitines (C < or = 12). 5. Long-chain acyl carnitines accumulated significantly in duckling skeletal muscle during cold acclimation. Accordingly, these results suggest that long-chain acyl metabolites may modulate SR Ca2+ cycling and its associated thermogenesis in vivo.
Collapse
Affiliation(s)
- E Dumonteil
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill 27599-7260
| | | | | |
Collapse
|
24
|
Yamada KA, McHowat J, Yan GX, Donahue K, Peirick J, Kléber AG, Corr PB. Cellular uncoupling induced by accumulation of long-chain acylcarnitine during ischemia. Circ Res 1994; 74:83-95. [PMID: 8261598 DOI: 10.1161/01.res.74.1.83] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Long-chain acylcarnitines (LCACs) increase rapidly within minutes after the onset of ischemia in vivo or hypoxia in vitro and produce a time-dependent reversible reduction in gap junctional conductance in isolated myocyte pairs. The present study was performed to assess whether LCACs contribute to cellular uncoupling in response to ischemia in isolated blood-perfused rabbit papillary muscles by use of simultaneous measurements of transmembrane action potentials, extracellular electrograms, extracellular K+, and tissue LCACs and ATP. LCACs increased threefold in response to 20 minutes of no-flow ischemia from 127 +/- 5 to 397 +/- 113 pmol/mg protein (P < .01), concomitant with the onset of cellular uncoupling, extracellular K+ accumulation, and a marked reduction in conduction velocity and action potential duration. To assess whether inhibition of the accumulation of LCACs modified the electrophysiological alterations during ischemia, muscles were pretreated with either sodium 2-(5-(4-chlorophenyl)-pentyl)-oxirane-2-carboxylate (POCA, 10 mumol/L) or oxfenicine (100 mumol/L), inhibitors of carnitine acyltransferase I. Both POCA and oxfenicine completely prevented the increase in LCACs even with 40 minutes of ischemia (138 +/- 37 and 56 +/- 4 pmol/mg protein, respectively), associated with a marked delay in the onset and progression of cellular uncoupling and ischemic contracture. Although POCA and oxfenicine did not affect either the initial early rise in extracellular K+ or the initial fall in conduction velocity, both agents markedly delayed the secondary rise in extracellular K+ as well as the secondary fall in conduction velocity, independent of the level of tissue ATP. Thus, LCACs accumulate during myocardial ischemia and contribute substantially to the initiation of cell-to-cell uncoupling. Inhibition of carnitine acyltransferase I and prevention of the increase in LCACs markedly delays cellular uncoupling and development of ischemic contracture in response to ischemia.
Collapse
Affiliation(s)
- K A Yamada
- Department of Internal Medicine, Washington University School of Medicine, St Louis, Mo 63110
| | | | | | | | | | | | | |
Collapse
|
25
|
el-Hayek R, Valdivia C, Valdivia HH, Hogan K, Coronado R. Activation of the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum by palmitoyl carnitine. Biophys J 1993; 65:779-89. [PMID: 8218902 PMCID: PMC1225778 DOI: 10.1016/s0006-3495(93)81101-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Studies of [3H]ryanodine binding, 45Ca2+ efflux, and single channel recordings in planar bilayers indicated that the fatty acid metabolite palmitoyl carnitine produced a direct stimulation of the Ca2+ release channel (ryanodine receptor) of rabbit and pig skeletal muscle junctional sarcoplasmic reticulum. At a concentration of 50 microM, palmitoyl carnitine (a) stimulated [3H]ryanodine binding 1.6-fold in a competitive manner at all pCa in the range 6 to 3; (b) released approximately 65% (30 nmol) of passively loaded 45Ca2+/mg protein; and (c) increased 7-fold the open probability of Ca2+ release channels incorporated into planar bilayers. Neither carnitine nor palmitic acid could reproduce the effect of palmitoyl carnitine on [3H]ryanodine binding, 45Ca2+ release, or channel open probability. 45Ca2+ release was induced by several long-chain acyl carnitines (C14, C16, C18) and acyl coenzyme A derivatives (C12, C14, C16), but not by the short-chain derivative C8 or by free saturated fatty acids of chain length C8 to C18, at room temperature or 36 degrees C. This newly identified interaction of esterified fatty acids and ryanodine receptors may represent a pathway by which metabolism of skeletal muscle could influence intracellular Ca2+ and may be responsible for the pathophysiology of disorders of beta-oxidation such as carnitine palmitoyl transferase II deficiency.
Collapse
Affiliation(s)
- R el-Hayek
- Department of Physiology, University of Wisconsin School of Medicine, Madison 53706
| | | | | | | | | |
Collapse
|
26
|
McHowat J, Yamada KA, Wu J, Yan GX, Corr PB. Recent insights pertaining to sarcolemmal phospholipid alterations underlying arrhythmogenesis in the ischemic heart. J Cardiovasc Electrophysiol 1993; 4:288-310. [PMID: 8269301 DOI: 10.1111/j.1540-8167.1993.tb01232.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Myocardial ischemia in vivo is associated with dramatic electrophysiologic alterations that occur within minutes of cessation of coronary flow and are rapidly reversible with reperfusion. This suggests that subtle and reversible biochemical alterations within or near the sarcolemma may contribute to the electrophysiologic derangements. Our studies have concentrated on two amphipathic metabolites, long-chain acylcarnitines and lysophosphatidylcholine (LPC), which have been shown to increase rapidly in ischemic tissue in vivo and to elicit electrophysiologic derangements in normoxic tissue in vitro. Incorporation of these amphiphiles into the sarcolemma at concentrations of 1 to 2 mole%, elicits profound electrophysiologic derangements analogous to those observed in ischemic myocardium in vivo. The pathophysiological effects of the accumulation of these amphiphiles are thought to be mediated by alterations in the biophysical properties of the sarcolemmal membrane, although there is a possibility of a direct effect upon ion channels. Inhibition of carnitine acyltransferase I (CAT-I) in the ischemic cat heart was found to prevent the increase in long-chain acylcarnitines and LPC and to significantly reduce the incidence of malignant arrhythmias including ventricular tachycardia and fibrillation. This review focuses on the electrophysiologic derangements that are observed during early ischemia and presents data supporting the concept that accumulation of these amphiphiles within the sarcolemma contributes to these changes. The potential contribution of these amphiphiles to the increases in extracellular potassium and intracellular calcium are examined. Finally, recent data pertaining to the accumulation of long-chain acylcarnitines on cell-to-cell uncoupling are presented. In addition to the events reviewed here, there are many other alterations that occur during early myocardial ischemia, but the results from multiple studies over the past two decades indicate that the accumulation of these amphiphiles contributes importantly to arrhythmogenesis and that development of specific inhibitors of CAT-I or phospholipase A2 may be a promising therapeutic strategy to attenuate the incidence of lethal arrhythmias associated with ischemic heart disease in man.
Collapse
Affiliation(s)
- J McHowat
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | | | | | | | | |
Collapse
|
27
|
Abstract
Evidence obtained from experimental animals and man indicates that reentry is a major mechanism underlying arrhythmogenesis. However, focal or nonreentrant mechanisms also appear to be operative under a wide variety of pathophysiologic conditions. For example, results obtained using three-dimensional (3D) mapping from 232 simultaneous sites in the feline heart in vivo revealed that nonreentrant or focal mechanisms were prominent during both ischemia and reperfusion. During early ischemia, nonreentrant mechanisms were responsible for initiation of ventricular tachycardia (VT) in 25% of cases and, in cases where VT was initiated by reentry, it often could be maintained by a nonreentrant mechanism. During reperfusion of ischemic myocardium, nonreentrant mechanisms were responsible for initiation of VT in 75% of cases. Most importantly, the transition from VT to ventricular fibrillation in response to reperfusion was secondary to acceleration of a nonreentrant mechanism in either the subendocardium or subepicardium. Potential cellular mechanisms include: 1) sarcolemmal accumulation of amphiphiles such as long-chain acylcarnitines and lysophosphatidylcholine; 2) alpha- and beta-adrenergic mediated effects of catecholamines on the transient inward current (ITI) secondary to an increase in intracellular Ca2+; and 3) alpha-adrenergic receptor-induced decrease in IK mediated by activation of protein kinase C. Recent findings obtained using 3D intraoperative mapping in patients with refractory VT and a previous myocardial infarction also indicate that both reentrant and nonreentrant or focal mechanisms contribute. For example, in 13 selected patients, mapping was of a sufficient resolution to define the mechanisms of 10 runs of VT. Intraoperative mapping indicated that five runs of VT were initiated by intramural reentry, whereas five runs of VT were initiated by a focal or nonreentrant mechanism. The mechanisms underlying ventricular arrhythmias associated with ischemic cardiomyopathy have recently been delineated in dogs after multiple sequential intracoronary embolizations with microspheres (with a decrease in mean ejection fraction from 64% to 25%). Spontaneous VT initiated by focal mechanisms from the subendocardium in 82% and epicardium in 18%, with no evidence of macroreentry. Thus, in divergent pathophysiologic settings, nonreentrant mechanisms appear to contribute importantly to the genesis of lethal ventricular arrhythmias, suggesting that development of novel therapeutic approaches should be directed at inhibition of not only reentrant circuits, but also nonreentrant mechanisms, including triggered activity.
Collapse
Affiliation(s)
- S M Pogwizd
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | | |
Collapse
|