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Pacak CA, Suzuki-Hatano S, Khadir F, Daugherty AL, Sriramvenugopal M, Gosiker BJ, Kang PB, Cade WT. One episode of low intensity aerobic exercise prior to systemic AAV9 administration augments transgene delivery to the heart and skeletal muscle. J Transl Med 2023; 21:748. [PMID: 37875924 PMCID: PMC10598899 DOI: 10.1186/s12967-023-04626-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/13/2023] [Indexed: 10/26/2023] Open
Abstract
INTRODUCTION The promising potential of adeno-associated virus (AAV) gene delivery strategies to treat genetic disorders continues to grow with an additional three AAV-based therapies recently approved by the Food and Drug Administration and dozens of others currently under evaluation in clinical trials. With these developments, it has become increasingly apparent that the high doses currently needed for efficacy carry risks of toxicity and entail enormous manufacturing costs, especially for clinical grade products. Strategies to increase the therapeutic efficacy of AAV-mediated gene delivery and reduce the minimal effective dose would have a substantial impact on this field. We hypothesized that an exercise-induced redistribution of tissue perfusion in the body to favor specific target organs via acute aerobic exercise prior to systemic intravenous (IV) AAV administration could increase efficacy. BACKGROUND Aerobic exercise triggers an array of downstream physiological effects including increased perfusion of heart and skeletal muscle, which we expected could enhance AAV transduction. Prior preclinical studies have shown promising results for a gene therapy approach to treat Barth syndrome (BTHS), a rare monogenic cardioskeletal myopathy, and clinical studies have shown the benefit of low intensity exercise in these patients, making this a suitable disease in which to test the ability of aerobic exercise to enhance AAV transduction. METHODS Wild-type (WT) and BTHS mice were either systemically administered AAV9 or completed one episode of low intensity treadmill exercise immediately prior to systemic administration of AAV9. RESULTS We demonstrate that a single episode of acute low intensity aerobic exercise immediately prior to IV AAV9 administration improves marker transgene delivery in WT mice as compared to mice injected without the exercise pre-treatment. In BTHS mice, prior exercise improved transgene delivery and additionally increased improvement in mitochondrial gene transcription levels and mitochondrial function in the heart and gastrocnemius muscles as compared to mice treated without exercise. CONCLUSIONS Our findings suggest that one episode of acute low intensity aerobic exercise improves AAV9 transduction of heart and skeletal muscle. This low-risk, cost effective intervention could be implemented in clinical trials of individuals with inherited cardioskeletal disease as a potential means of improving patient safety for human gene therapy.
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Affiliation(s)
- Christina A Pacak
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA.
| | - Silveli Suzuki-Hatano
- College of Medicine, Department of Pediatrics, University of Florida, Gainesville, USA
| | - Fatemeh Khadir
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | - Audrey L Daugherty
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | | | - Bennett J Gosiker
- College of Medicine, Department of Pediatrics, University of Florida, Gainesville, USA
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | - William Todd Cade
- Physical Therapy Division, Department of Orthopaedic Surgery, Duke University School of Medicine, 311 Trent Drive, Durham, NC, 27710, USA.
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Tomczewski MV, Chan JZ, Al-Majmaie DM, Liu MR, Cocco AD, Stark KD, Strathdee D, Duncan RE. Phenotypic Characterization of Female Carrier Mice Heterozygous for Tafazzin Deletion. BIOLOGY 2023; 12:1238. [PMID: 37759637 PMCID: PMC10525480 DOI: 10.3390/biology12091238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/02/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023]
Abstract
Barth syndrome (BTHS) is caused by mutations in tafazzin resulting in deficits in cardiolipin remodeling that alter major metabolic processes. The tafazzin gene is encoded on the X chromosome, and therefore BTHS primarily affects males. Female carriers are typically considered asymptomatic, but age-related changes have been reported in female carriers of other X-linked disorders. Therefore, we examined the phenotype of female mice heterozygous for deletion of the tafazzin gene (Taz-HET) at 3 and 12 months of age. Food intakes, body masses, lean tissue and adipose depot weights, daily activity levels, metabolic measures, and exercise capacity were assessed. Age-related changes in mice resulted in small but significant genotype-specific differences in Taz-HET mice compared with their female Wt littermates. By 12 months, Taz-HET mice weighed less than Wt controls and had smaller gonadal, retroperitoneal, and brown adipose depots and liver and brain masses, despite similar food consumption. Daily movement, respiratory exchange ratio, and total energy expenditure did not vary significantly between the age-matched genotypes. Taz-HET mice displayed improved glucose tolerance and insulin sensitivity at 12 months compared with their Wt littermates but had evidence of slightly reduced exercise capacity. Tafazzin mRNA levels were significantly reduced in the cardiac muscle of 12-month-old Taz-HET mice, which was associated with minor but significant alterations in the heart cardiolipin profile. This work is the first to report the characterization of a model of female carriers of heterozygous tafazzin deficiency and suggests that additional study, particularly with advancing age, is warranted.
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Affiliation(s)
- Michelle V. Tomczewski
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - John Z. Chan
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Duaa M. Al-Majmaie
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Ming Rong Liu
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Alex D. Cocco
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Ken D. Stark
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Douglas Strathdee
- Transgenic Technology Laboratory, Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, Scotland, UK;
| | - Robin E. Duncan
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
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Wang S, Yazawa E, Keating EM, Mazumdar N, Hauschild A, Ma Q, Wu H, Xu Y, Shi X, Strathdee D, Gerszten RE, Schlame M, Pu WT. Genetic modifiers modulate phenotypic expression of tafazzin deficiency in a mouse model of Barth syndrome. Hum Mol Genet 2023; 32:2055-2067. [PMID: 36917259 PMCID: PMC10244222 DOI: 10.1093/hmg/ddad041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/27/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Barth syndrome is an X-linked disorder caused by loss-of-function mutations in Tafazzin (TAZ), an acyltransferase that catalyzes remodeling of cardiolipin, a signature phospholipid of the inner mitochondrial membrane. Patients develop cardiac and skeletal muscle weakness, growth delay and neutropenia, although phenotypic expression varies considerably between patients. Taz knockout mice recapitulate many of the hallmark features of the disease. We used mouse genetics to test the hypothesis that genetic modifiers alter the phenotypic manifestations of Taz inactivation. We crossed TazKO/X females in the C57BL6/J inbred strain to males from eight inbred strains and evaluated the phenotypes of first-generation (F1) TazKO/Y progeny, compared to TazWT/Y littermates. We observed that genetic background strongly impacted phenotypic expression. C57BL6/J and CAST/EiJ[F1] TazKO/Y mice developed severe cardiomyopathy, whereas A/J[F1] TazKO/Y mice had normal heart function. C57BL6/J and WSB/EiJ[F1] TazKO/Y mice had severely reduced treadmill endurance, whereas endurance was normal in A/J[F1] and CAST/EiJ[F1] TazKO/Y mice. In all genetic backgrounds, cardiolipin showed similar abnormalities in knockout mice, and transcriptomic and metabolomic investigations identified signatures of mitochondrial uncoupling and activation of the integrated stress response. TazKO/Y cardiac mitochondria were small, clustered and had reduced cristae density in knockouts in severely affected genetic backgrounds but were relatively preserved in the permissive A/J[F1] strain. Gene expression and mitophagy measurements were consistent with reduced mitophagy in knockout mice in genetic backgrounds intolerant of Taz mutation. Our data demonstrate that genetic modifiers powerfully modulate phenotypic expression of Taz loss-of-function and act downstream of cardiolipin, possibly by altering mitochondrial quality control.
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Affiliation(s)
- Suya Wang
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Erika Yazawa
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Erin M Keating
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Neil Mazumdar
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Alexander Hauschild
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Qing Ma
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
| | - Haiyan Wu
- Department of Pharmacology, Sichuan University West China School of Basic Sciences and Forensic Medicine, Chengdu, Sichuan, China
| | - Yang Xu
- Department of Anesthesiology, New York University School of Medicine, New York, NY, USA
| | - Xu Shi
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Douglas Strathdee
- Transgenic Technology Laboratory, Cancer Research UK Beatson Institute, Glasgow, UK
| | - Robert E Gerszten
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
| | - Michael Schlame
- Department of Anesthesiology, New York University School of Medicine, New York, NY, USA
| | - William T Pu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02215NYU 10016, USA
- Transgenic Technology Laboratory, Cancer Research UK Beatson Institute, Glasgow, UK
- Harvard Stem Cell Institute, Harvard University, 02138 Beatson, Cambridge, MA G61 1BD, USA
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Mahmud SZ, Bashir A. Repeatability assessment for simultaneous measurement of arterial blood flow, venous oxygen saturation, and muscle perfusion following dynamic exercise. NMR IN BIOMEDICINE 2023; 36:e4872. [PMID: 36349386 DOI: 10.1002/nbm.4872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 11/04/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
The purpose of the present study was to demonstrate a new sequence and determine the repeatability of simultaneous dynamic measurements of blood flow, venous oxygen saturation (SvO2 ), and relative perfusion (change from resting perfusion) in calf muscle during recovery from plantar flexion exercise. The feasibility of near simultaneous measurement of bio-energetic parameters was also demonstrated. A sequence was developed to simultaneously measure arterial blood flow using flow-encoded projection, SvO2 using susceptibility-based oximetry, and relative perfusion using arterial spin labeling in combination with dynamic plantar flexion exercise. The parameters were determined at rest and during recovery from single leg plantar flexion exercise. Test-retest repeatability was analyzed using Bland-Altman analysis and intraclass correlation coefficients (ICC). The mitochondrial capacity of skeletal muscle was also measured immediately afterwards with dynamic phosphorus magnetic resonance spectroscopy. Eight healthy subjects participated in the study for test-retest repeatability. Popliteal artery blood flow at rest was 1.79 ± 0.58 ml/s and increased to 11.18 ± 3.02 ml/s immediately after exercise. Popliteal vein SvO2 decreased to 45.93% ± 6.5% from a resting value of 70.46% ± 4.76% following exercise. Relative perfusion (change from rest value) was 51.83 ± 15.00 ml/100 g/min at the cessation of exercise. The recovery of blood flow and SvO2 was modeled as a single exponential with time constants of 38.03 ± 6.91 and 71.19 ± 14.53 s, respectively. All the measured parameters exhibited good repeatability with ICC ranging from 0.8 to 0.95. Bioenergetics measurements were within normal range, demonstrating the feasibility of near simultaneous measurement of hemodynamic and energetic parameters. Clinical feasibility was assessed with Barth syndrome patients, demonstrating reduced oxygen extraction from the blood and reduced mitochondrial oxidative capacity compared with healthy controls. The proposed protocol allows rapid imaging of multiple parameters in skeletal muscle that might be affected in disease.
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Affiliation(s)
- Sultan Z Mahmud
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
| | - Adil Bashir
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
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Phenotypic Characterization of Male Tafazzin-Knockout Mice at 3, 6, and 12 Months of Age. Biomedicines 2023; 11:biomedicines11020638. [PMID: 36831174 PMCID: PMC9953241 DOI: 10.3390/biomedicines11020638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Barth syndrome (BTHS) is an X-linked mitochondrial disease caused by mutations in the gene encoding for tafazzin (TAZ), a key enzyme in the remodeling of cardiolipin. Mice with a germline deficiency in Taz have been generated (Taz-KO) but not yet fully characterized. We performed physiological assessments of 3-, 6-, and 12-month-old male Taz-KO mice, including measures of perinatal survival, growth, lifespan, gross anatomy, whole-body energy and substrate metabolism, glucose homeostasis, and exercise capacity. Taz-KO mice displayed reduced viability, with lower-than-expected numbers of mice recorded at 4 weeks of age, and a shortened lifespan due to disease progression. At all ages, Taz-KO mice had lower body weights compared with wild-type (Wt) littermates despite similar absolute food intakes. This finding was attributed to reduced adiposity and diminutive organs and tissues, including heart and skeletal muscles. Although there were no differences in basal levels of locomotion between age-matched genotypes, indirect calorimetry studies showed higher energy expenditure measures and respiratory exchange ratios in Taz-KO mice. At the youngest age, Taz-KO mice had comparable glucose tolerance and insulin action to Wt mice, but while these measures indicated metabolic impairments in Wt mice with advancing age that were likely associated with increasing adiposity, Taz-KO mice were protected. Comparisons across the three age-cohorts revealed a significant and more severe deterioration of exercise capacity in Taz-KO mice than in their Wt littermate controls. The Taz-KO mouse model faithfully recapitulates important aspects of BTHS, and thus provides an important new tool to investigate pathophysiological mechanisms and potential therapies.
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Heine KB, Parry HA, Hood WR. How does density of the inner mitochondrial membrane influence mitochondrial performance? Am J Physiol Regul Integr Comp Physiol 2023; 324:R242-R248. [PMID: 36572555 PMCID: PMC9902215 DOI: 10.1152/ajpregu.00254.2022] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/21/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022]
Abstract
Our current understanding of variation in mitochondrial performance is incomplete. The production of ATP via oxidative phosphorylation is dependent, in part, on the structure of the inner mitochondrial membrane. Morphology of the inner membrane is crucial for the formation of the proton gradient across the inner membrane and, therefore, ATP synthesis. The inner mitochondrial membrane is dynamic, changing shape and surface area. These changes alter density (amount per volume) of the inner mitochondrial membrane within the confined space of the mitochondrion. Because the number of electron transport system proteins within the inner mitochondrial membrane changes with inner mitochondrial membrane area, a change in the amount of inner membrane alters the capacity for ATP production within the organelle. This review outlines the evidence that the association between ATP synthases, inner mitochondrial membrane density, and mitochondrial density (number of mitochondria per cell) impacts ATP production by mitochondria. Furthermore, we consider possible constraints on the capacity of mitochondria to produce ATP by increasing inner mitochondrial membrane density.
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Affiliation(s)
- Kyle B Heine
- Department of Biological Sciences, Auburn University, Auburn, Alabama
| | - Hailey A Parry
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, Alabama
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7
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Piñeiro-Llanes J, Suzuki-Hatano S, Jain A, Pérez Medina VA, Cade WT, Pacak CA, Simmons CS. Matrix produced by diseased cardiac fibroblasts affects early myotube formation and function. Acta Biomater 2022; 152:100-112. [PMID: 36055608 PMCID: PMC10625442 DOI: 10.1016/j.actbio.2022.08.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 08/25/2022] [Accepted: 08/25/2022] [Indexed: 11/28/2022]
Abstract
The extracellular matrix (ECM) provides both physical and chemical cues that dictate cell function and contribute to muscle maintenance. Muscle cells require efficient mitochondria to satisfy their high energy demand, however, the role the ECM plays in moderating mitochondrial function is not clear. We hypothesized that the ECM produced by stromal cells with mitochondrial dysfunction (Barth syndrome, BTHS) provides cues that contribute to metabolic dysfunction independent of muscle cell health. To test this, we harnessed the ECM production capabilities of human pluripotent stem-cell-derived cardiac fibroblasts (hPSC-CFs) from healthy and BTHS patients to fabricate cell-derived matrices (CDMs) with controlled topography, though we found that matrix composition from healthy versus diseased cells influenced myotube formation independent of alignment cues. To further investigate the effects of matrix composition, we then examined the influence of healthy- and BTHS-derived CDMs on myotube formation and metabolic function. We found that BTHS CDMs induced lower fusion index, lower ATP production, lower mitochondrial membrane potential, and higher ROS generation than the healthy CDMs. These findings imply that BTHS-derived ECM alone contributes to myocyte dysfunction in otherwise healthy cells. Finally, to investigate potential mechanisms, we defined the composition of CDMs produced by hPSC-CFs from healthy and BTHS patients using mass spectrometry and identified 15 ECM and related proteins that were differentially expressed in the BTHS-CDM compared to healthy CDM. Our results highlight that ECM composition affects skeletal muscle formation and metabolic efficiency in otherwise healthy cells, and our methods to generate patient-specific CDMs are a useful tool to investigate the influence of the ECM on disease progression and to investigate variability among diseased patients. STATEMENT OF SIGNIFICANCE: Muscle function requires both efficient metabolism to generate force and structured extracellular matrix (ECM) to transmit force, and we sought to examine the interactions between metabolism and ECM when metabolic disease is present. We fabricated patient-specific cell derived matrices (CDMs) with controlled topographic features to replicate the composition of healthy and mitochondrial-diseased (Barth syndrome) ECM. We found that disease-derived ECM negatively affects metabolic function of otherwise healthy myoblasts, and we identified several proteins in disease-derived ECM that may be mediating this dysfunction. We anticipate that our patient-specific CDM system could be fabricated with other topographies and cell types to study cell functions and diseases of interest beyond mitochondrial dysfunction and, eventually, be applied toward personalized medicine.
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Affiliation(s)
- Janny Piñeiro-Llanes
- J. Crayton Pruitt Family Department of Biomedical Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Ananya Jain
- J. Crayton Pruitt Family Department of Biomedical Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Valerie A Pérez Medina
- Department of Mechanical Engineering, University of Puerto Rico, Mayaguez 00682, Puerto Rico
| | - William Todd Cade
- Physical Therapy Division, Duke University, 311 Trent Drive, Durham, NC 27710, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA; Neurology Department, Medical School, University of Minnesota, WMBB 4-188 2101 6th Street SE, Minneapolis 55455, USA
| | - Chelsey S Simmons
- J. Crayton Pruitt Family Department of Biomedical Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL 32611, USA; Department of Mechanical and Aerospace Engineering Herbert Wertheim College of Engineering, University of Florida.
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Greenwell AA, Tabatabaei Dakhili SA, Ussher JR. Myocardial disturbances of intermediary metabolism in Barth syndrome. Front Cardiovasc Med 2022; 9:981972. [PMID: 36035919 PMCID: PMC9399503 DOI: 10.3389/fcvm.2022.981972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Barth Syndrome (BTHS) is a rare X-linked mitochondrial disorder due to mutations in the gene TAFAZZIN, which leads to immature cardiolipin (CL) remodeling and is characterized by the development of cardiomyopathy. The immature CL remodeling in BTHS results in electron transport chain respiratory defects and destabilization of supercomplexes, thereby impairing ATP production. Thus, BTHS-related cardiomyopathy appears to share metabolic characteristics of the failing heart being an "engine out of fuel." As CL associates with numerous mitochondrial enzymes involved in ATP production, BTHS is also characterized by several defects in intermediary energy metabolism. Herein we will describe the primary disturbances in intermediary energy metabolism relating to the heart's major fuel sources, fatty acids, carbohydrates, ketones, and amino acids. In addition, we will interrogate whether these disturbances represent potential metabolic targets for alleviating BTHS-related cardiomyopathy.
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Affiliation(s)
- Amanda A. Greenwell
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
- Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada
| | - Seyed Amirhossein Tabatabaei Dakhili
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
- Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada
| | - John R. Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
- Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada
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Chowdhury S, Jackson L, Byrne BJ, Bryant RM, Cade WT, Churchill TL, Buchanan J, Taylor C. Longitudinal Observational Study of Cardiac Outcome Risk Factor Prediction in Children, Adolescents, and Adults with Barth Syndrome. Pediatr Cardiol 2022; 43:1251-1263. [PMID: 35238957 PMCID: PMC9462389 DOI: 10.1007/s00246-022-02846-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 02/04/2022] [Indexed: 12/01/2022]
Abstract
Barth Syndrome (BTHS) is an X-linked mitochondrial cardioskeletal myopathy caused by defects in TAFAZZIN, a gene responsible for cardiolipin remodeling. Altered mitochondrial levels of cardiolipin lead to cardiomyopathy (CM), muscle weakness, exercise intolerance, and mortality. Cardiac risk factors predicting outcome are unknown. Therefore, we conducted a longitudinal observational study to determine risk factors for outcome in BTHS. Subjects with minimum two evaluations (or one followed by death or transplant) were included. Cardiac size, function, and QTc data were measured by echocardiography and electrocardiography at 7 time points from 2002 to 2018. Analysis included baseline, continuous, and categorical variables. Categorical risk factors included prolonged QTc, abnormal right ventricle fractional area change (RV FAC), left ventricle (LV) or RV non-compaction, and restrictive CM phenotype. The association between variables and cardiac death or transplant (CD/TX) was assessed. Median enrollment age was 7 years (range 0.5-22; n = 44). Transplant-free survival (TFS) was 74.4% at 15 years from first evaluation. The cohort demonstrated longitudinal declines in LV size and stroke volume z-scores (end-diastolic volume, p = 0.0002; stroke volume p < 0.0001), worsening RV FAC (p = 0.0405), and global longitudinal strain (GLS) (p = 0.0001) with stable ejection (EF) and shortening (FS) fraction. CD/TX subjects (n = 9) displayed worsening LV dilation (p = 0.0066), EF (p ≤ 0.0001), FS (p = 0.0028), and RV FAC (p = .0032) versus stability in TFS. Having ≥ 2 categorical risk factors predicted CD/TX (p = 0.0073). Over 15 years, 25% of BTHS subjects progressed to CD/TX. Those with progressive LV enlargement, dysfunction, and multiple cardiac risk factors warrant increased surveillance and intense therapy.
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Affiliation(s)
| | - Lanier Jackson
- Medical University of South Carolina, Charleston, SC, USA
| | - Barry J. Byrne
- School of Medicine, University of Florida, Gainesville, FL, USA
| | | | - W. Todd Cade
- Duke University School of Medicine, Durham, NC, USA
| | | | - Julia Buchanan
- Medical University of South Carolina, Charleston, SC, USA
| | - Carolyn Taylor
- MUSC Children's Heart Program, Pediatric Echocardiography Lab, Pediatric Cardiology, Shawn Jenkins Children's Hospital, MSC 915, 10 McClennan Banks Dr., Charleston, SC, 29425-8905, USA.
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Bertero E, Nickel A, Kohlhaas M, Hohl M, Sequeira V, Brune C, Schwemmlein J, Abeßer M, Schuh K, Kutschka I, Carlein C, Münker K, Atighetchi S, Müller A, Kazakov A, Kappl R, von der Malsburg K, van der Laan M, Schiuma AF, Böhm M, Laufs U, Hoth M, Rehling P, Kuhn M, Dudek J, von der Malsburg A, Prates Roma L, Maack C. Loss of Mitochondrial Ca 2+ Uniporter Limits Inotropic Reserve and Provides Trigger and Substrate for Arrhythmias in Barth Syndrome Cardiomyopathy. Circulation 2021; 144:1694-1713. [PMID: 34648376 DOI: 10.1161/circulationaha.121.053755] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Barth syndrome (BTHS) is caused by mutations of the gene encoding tafazzin, which catalyzes maturation of mitochondrial cardiolipin and often manifests with systolic dysfunction during early infancy. Beyond the first months of life, BTHS cardiomyopathy typically transitions to a phenotype of diastolic dysfunction with preserved ejection fraction, blunted contractile reserve during exercise, and arrhythmic vulnerability. Previous studies traced BTHS cardiomyopathy to mitochondrial formation of reactive oxygen species (ROS). Because mitochondrial function and ROS formation are regulated by excitation-contraction coupling, integrated analysis of mechano-energetic coupling is required to delineate the pathomechanisms of BTHS cardiomyopathy. METHODS We analyzed cardiac function and structure in a mouse model with global knockdown of tafazzin (Taz-KD) compared with wild-type littermates. Respiratory chain assembly and function, ROS emission, and Ca2+ uptake were determined in isolated mitochondria. Excitation-contraction coupling was integrated with mitochondrial redox state, ROS, and Ca2+ uptake in isolated, unloaded or preloaded cardiac myocytes, and cardiac hemodynamics analyzed in vivo. RESULTS Taz-KD mice develop heart failure with preserved ejection fraction (>50%) and age-dependent progression of diastolic dysfunction in the absence of fibrosis. Increased myofilament Ca2+ affinity and slowed cross-bridge cycling caused diastolic dysfunction, in part, compensated by accelerated diastolic Ca2+ decay through preactivated sarcoplasmic reticulum Ca2+-ATPase. Taz deficiency provoked heart-specific loss of mitochondrial Ca2+ uniporter protein that prevented Ca2+-induced activation of the Krebs cycle during β-adrenergic stimulation, oxidizing pyridine nucleotides and triggering arrhythmias in cardiac myocytes. In vivo, Taz-KD mice displayed prolonged QRS duration as a substrate for arrhythmias, and a lack of inotropic response to β-adrenergic stimulation. Cellular arrhythmias and QRS prolongation, but not the defective inotropic reserve, were restored by inhibiting Ca2+ export through the mitochondrial Na+/Ca2+ exchanger. All alterations occurred in the absence of excess mitochondrial ROS in vitro or in vivo. CONCLUSIONS Downregulation of mitochondrial Ca2+ uniporter, increased myofilament Ca2+ affinity, and preactivated sarcoplasmic reticulum Ca2+-ATPase provoke mechano-energetic uncoupling that explains diastolic dysfunction and the lack of inotropic reserve in BTHS cardiomyopathy. Furthermore, defective mitochondrial Ca2+ uptake provides a trigger and a substrate for ventricular arrhythmias. These insights can guide the ongoing search for a cure of this orphaned disease.
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Affiliation(s)
- Edoardo Bertero
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Now with Department of Internal Medicine and Specialties (Di.M.I.), University of Genoa, Italy (E.B.)
| | - Alexander Nickel
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Michael Kohlhaas
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Mathias Hohl
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Vasco Sequeira
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Carolin Brune
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Julia Schwemmlein
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Marco Abeßer
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Kai Schuh
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Ilona Kutschka
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Christopher Carlein
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Kai Münker
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Sarah Atighetchi
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Andreas Müller
- Clinic for Radiology (A.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Andrey Kazakov
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Reinhard Kappl
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Karina von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Martin van der Laan
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Anna-Florentine Schiuma
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.)
| | - Michael Böhm
- Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany
| | - Ulrich Laufs
- Now with Klinik und Poliklinik für Kardiologie, Universitätsklinikum Leipzig, Germany (U.L.)
| | - Markus Hoth
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, Georg-August University, Göttingen, Germany (P.R., J.D.).,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Germany (P.R.).,Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany (P.R.)
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg, Germany (M.A., K.S., M. Kuhn)
| | - Jan Dudek
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Department of Cellular Biochemistry, Georg-August University, Göttingen, Germany (P.R., J.D.)
| | - Alexander von der Malsburg
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling, PZMS, Faculty of Medicine (K.v.d.M., M.v.d.L., A.v.d.M.), Saarland University, Homburg/Saar, Germany
| | - Leticia Prates Roma
- Department for Biophysics, ZHMB, CIPMM (C.C., R.K., M. Hoth, L.P.R.), Saarland University, Homburg/Saar, Germany
| | - Christoph Maack
- Department of Translational Research, Comprehensive Heart Failure Center, University Clinic, Würzburg, Germany (E.B., A.N., M. Kohlhaas, V.S., J.S., I.K., K.M., S.A., A.-F.S., J.D., C.M.).,Clinic for Internal Medicine III (M. Hohl, C.B., K.M., S.A., A.K., M.B., C.M.), Saarland University Clinic, Homburg/Saar, Germany.,Department for Internal Medicine 1, University Clinic Würzburg, Germany (C.M.)
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11
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Bohnert KL, Ditzenberger G, Bittel AJ, de las Fuentes L, Corti M, Pacak CA, Taylor C, Byrne BJ, Reeds DN, Cade WT. Resistance exercise training with protein supplementation improves skeletal muscle strength and improves quality of life in late adolescents and young adults with Barth syndrome: A pilot study. JIMD Rep 2021; 62:74-84. [PMID: 34765401 PMCID: PMC8574175 DOI: 10.1002/jmd2.12244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/19/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Muscle weakness and exercise intolerance contribute to reduced quality of life (QOL) in Barth syndrome (BTHS). Our group previously found that 12 weeks of resistance exercise training (RET) improved muscle strength, however, did not increase muscle (lean) mass or QOL in n = 3 young adults with BTHS. The overall objective of this pilot study was to examine the safety and effectiveness of RET plus daily protein supplementation (RET + protein) on muscle strength, skeletal muscle mass, exercise tolerance, cardiac function, and QOL in late adolescents/young adults with BTHS. METHODS Participants with BTHS (n = 5, age 27 ± 7) performed 12 weeks of supervised RET (60 minutes per session, three sessions/week) and consumed 42 g/day of whey protein. Muscle strength, muscle mass, exercise capacity, cardiac function, and health-related QOL were assessed pre-post intervention. RESULTS RET + protein was safe, increased muscle strength and quality of life, and tended to increase lean mass. CONCLUSIONS RET + protein appears safe, increases muscle strength and quality of life and tends to increase lean mass. Larger studies are needed to confirm these findings and to fully determine the effects of RET + protein in individuals with BTHS.
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Affiliation(s)
- Kathryn L. Bohnert
- Program in Physical TherapyWashington University School of MedicineSt. LouisMissouriUSA
| | - Grace Ditzenberger
- Doctor of Physical Therapy DivisionDuke University School of MedicineDurhamNorth CarolinaUSA
| | - Adam J. Bittel
- Program in Physical TherapyWashington University School of MedicineSt. LouisMissouriUSA
| | - Lisa de las Fuentes
- Department of MedicineWashington University School of MedicineSt. LouisMissouriUSA
| | - Manuela Corti
- Department of PediatricsUniversity of Florida School of MedicineGainesvilleFloridaUSA
| | - Christina A. Pacak
- Department of PediatricsUniversity of Florida School of MedicineGainesvilleFloridaUSA
| | - Carolyn Taylor
- Department of PediatricsMedical University of South CarolinaChalestonSouth CarolinaUSA
| | - Barry J. Byrne
- Department of PediatricsUniversity of Florida School of MedicineGainesvilleFloridaUSA
| | - Dominic N. Reeds
- Department of MedicineWashington University School of MedicineSt. LouisMissouriUSA
- Center for Human NutritionWashington University School of MedicineSt. LouisMissouriUSA
| | - W. Todd Cade
- Program in Physical TherapyWashington University School of MedicineSt. LouisMissouriUSA
- Doctor of Physical Therapy DivisionDuke University School of MedicineDurhamNorth CarolinaUSA
- Department of MedicineWashington University School of MedicineSt. LouisMissouriUSA
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12
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Elkes M, Andonovski M, Vidal D, Farago M, Modafferi R, Claypool SM, LeBlanc PJ. The Influence of Supplemental Dietary Linoleic Acid on Skeletal Muscle Contractile Function in a Rodent Model of Barth Syndrome. Front Physiol 2021; 12:731961. [PMID: 34489741 PMCID: PMC8416984 DOI: 10.3389/fphys.2021.731961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/02/2021] [Indexed: 11/13/2022] Open
Abstract
Barth syndrome is a rare and incurable X-linked (male-specific) genetic disease that affects the protein tafazzin (Taz). Taz is an important enzyme responsible for synthesizing biologically relevant cardiolipin (for heart and skeletal muscle, cardiolipin rich in linoleic acid), a critical phospholipid of mitochondrial form and function. Mutations to Taz cause dysfunctional mitochondria, resulting in exercise intolerance due to skeletal muscle weakness. To date, there has been limited research on improving skeletal muscle function, with interventions focused on endurance and resistance exercise. Previous cell culture research has shown therapeutic potential for the addition of exogenous linoleic acid in improving Taz-deficient mitochondrial function but has not been examined in vivo. The purpose of this study was to examine the influence of supplemental dietary linoleic acid on skeletal muscle function in a rodent model of Barth syndrome, the inducible Taz knockdown (TazKD) mouse. One of the main findings was that TazKD soleus demonstrated an impaired contractile phenotype (slower force development and rates of relaxation) in vitro compared to their WT littermates. Interestingly, this impaired contractile phenotype seen in vitro did not translate to altered muscle function in vivo at the whole-body level. Also, supplemental linoleic acid attenuated, to some degree, in vitro impaired contractile phenotype in TazKD soleus, and these findings appear to be partially mediated by improvements in cardiolipin content and resulting mitochondrial supercomplex formation. Future research will further examine alternative mechanisms of dietary supplemental LA on improving skeletal muscle contractile dysfunction in TazKD mice.
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Affiliation(s)
- Mario Elkes
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Martin Andonovski
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Daislyn Vidal
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Madison Farago
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Ryan Modafferi
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Paul J LeBlanc
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
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13
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Cade WT, Laforest R, Bohnert KL, Reeds DN, Bittel AJ, de Las Fuentes L, Bashir A, Woodard PK, Pacak CA, Byrne BJ, Gropler RJ, Peterson LR. Myocardial glucose and fatty acid metabolism is altered and associated with lower cardiac function in young adults with Barth syndrome. J Nucl Cardiol 2021; 28:1649-1659. [PMID: 31705425 PMCID: PMC7205570 DOI: 10.1007/s12350-019-01933-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/07/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Barth syndrome (BTHS) is a rare X-linked condition resulting in cardiomyopathy, however; the effects of BTHS on myocardial substrate metabolism and its relationships with cardiac high-energy phosphate metabolism and left ventricular (LV) function are unknown. We sought to characterize myocardial glucose, fatty acid (FA), and leucine metabolism in BTHS and unaffected controls and examine their relationships with cardiac high-energy phosphate metabolism and LV function. METHODS/RESULTS Young adults with BTHS (n = 14) and unaffected controls (n = 11, Control, total n = 25) underwent bolus injections of 15O-water and 1-11C-glucose, palmitate, and leucine and concurrent positron emission tomography imaging. LV function and cardiac high-energy phosphate metabolism were examined via echocardiography and 31P magnetic resonance spectroscopy, respectively. Myocardial glucose extraction fraction (21 ± 14% vs 10 ± 8%, P = .03) and glucose utilization (828.0 ± 470.0 vs 393.2 ± 361.0 μmol·g-1·min-1, P = .02) were significantly higher in BTHS vs Control. Myocardial FA extraction fraction (31 ± 7% vs 41 ± 6%, P < .002) and uptake (0.25 ± 0.04 vs 0.29 ± 0.03 mL·g-1·min-1, P < .002) were significantly lower in BTHS vs Control. Altered myocardial metabolism was associated with lower cardiac function in BTHS. CONCLUSIONS Myocardial substrate metabolism is altered and may contribute to LV dysfunction in BTHS. Clinical Trials #: NCT01625663.
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Affiliation(s)
- William Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA.
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
| | - Richard Laforest
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kathryn L Bohnert
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA
| | - Dominic N Reeds
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Adam J Bittel
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA
| | - Lisa de Las Fuentes
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Adil Bashir
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
| | - Pamela K Woodard
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Robert J Gropler
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Linda R Peterson
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
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14
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Liu X, Wang S, Guo X, Li Y, Ogurlu R, Lu F, Prondzynski M, Buzon SDLS, Ma Q, Zhang D, Wang G, Cotton J, Guo Y, Xiao L, Milan DJ, Xu Y, Schlame M, Bezzerides VJ, Pu WT. Increased Reactive Oxygen Species-Mediated Ca 2+/Calmodulin-Dependent Protein Kinase II Activation Contributes to Calcium Handling Abnormalities and Impaired Contraction in Barth Syndrome. Circulation 2021; 143:1894-1911. [PMID: 33793303 PMCID: PMC8691127 DOI: 10.1161/circulationaha.120.048698] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Mutations in tafazzin (TAZ), a gene required for biogenesis of cardiolipin, the signature phospholipid of the inner mitochondrial membrane, causes Barth syndrome (BTHS). Cardiomyopathy and risk of sudden cardiac death are prominent features of BTHS, but the mechanisms by which impaired cardiolipin biogenesis causes cardiac muscle weakness and arrhythmia are poorly understood. METHODS We performed in vivo electrophysiology to define arrhythmia vulnerability in cardiac-specific TAZ knockout mice. Using cardiomyocytes derived from human induced pluripotent stem cells and cardiac-specific TAZ knockout mice as model systems, we investigated the effect of TAZ inactivation on Ca2+ handling. Through genome editing and pharmacology, we defined a molecular link between TAZ mutation and abnormal Ca2+ handling and contractility. RESULTS A subset of mice with cardiac-specific TAZ inactivation developed arrhythmias, including bidirectional ventricular tachycardia, atrial tachycardia, and complete atrioventricular block. Compared with wild-type controls, BTHS-induced pluripotent stem cell-derived cardiomyocytes had increased diastolic Ca2+ and decreased Ca2+ transient amplitude. BTHS-induced pluripotent stem cell-derived cardiomyocytes had higher levels of mitochondrial and cellular reactive oxygen species than wild-type controls, which activated CaMKII (Ca2+/calmodulin-dependent protein kinase II). Activated CaMKII phosphorylated the RYR2 (ryanodine receptor 2) on serine 2814, increasing Ca2+ leak through RYR2. Inhibition of this reactive oxygen species-CaMKII-RYR2 pathway through pharmacological inhibitors or genome editing normalized aberrant Ca2+ handling in BTHS-induced pluripotent stem cell-derived cardiomyocytes and improved their contractile function. Murine Taz knockout cardiomyocytes also exhibited elevated diastolic Ca2+ and decreased Ca2+ transient amplitude. These abnormalities were ameliorated by Ca2+/calmodulin-dependent protein kinase II or reactive oxygen species inhibition. CONCLUSIONS This study identified a molecular pathway that links TAZ mutation with abnormal Ca2+ handling and decreased cardiomyocyte contractility. This pathway may offer therapeutic opportunities to treat BTHS and potentially other diseases with elevated mitochondrial reactive oxygen species production.
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Affiliation(s)
- Xujie Liu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Radiology, Basic Medical School, Chongqing Medical University, Chongqing, 400016, China
| | - Suya Wang
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Xiaoling Guo
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
- Center of Scientific Research, the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Roza Ogurlu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Fujian Lu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | | | | | - Qing Ma
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Donghui Zhang
- State key laboratory of Biocatalysis and Enzyme Engineering, School of Life Science, Hubei University, Wuhan, Hubei 430062, China
| | - Gang Wang
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Justin Cotton
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard College, Cambridge, MA 02138, USA
| | - Yuxuan Guo
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Ling Xiao
- Department of Cardiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - David J. Milan
- Department of Cardiology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Yang Xu
- Department of Anesthesiology, New York University School of Medicine, New York, New York
| | - Michael Schlame
- Department of Anesthesiology, New York University School of Medicine, New York, New York
| | | | - William T. Pu
- Department of Cardiology, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard Stem Cell Institute, Cambridge, MA 02138, USA
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15
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Abstract
Barth syndrome (BTHS) is a rare, X-linked recessive, infantile-onset debilitating disorder characterized by early-onset cardiomyopathy, skeletal muscle myopathy, growth delay, and neutropenia, with a worldwide incidence of 1/300,000-400,000 live births. The high mortality rate throughout infancy in BTHS patients is related primarily to progressive cardiomyopathy and a weakened immune system. BTHS is caused by defects in the TAZ gene that encodes tafazzin, a transacylase responsible for the remodeling and maturation of the mitochondrial phospholipid cardiolipin (CL), which is critical to normal mitochondrial structure and function (i.e., ATP generation). A deficiency in tafazzin results in up to a 95% reduction in levels of structurally mature CL. Because the heart is the most metabolically active organ in the body, with the highest mitochondrial content of any tissue, mitochondrial dysfunction plays a key role in the development of heart failure in patients with BTHS. Changes in mitochondrial oxidative phosphorylation reduce the ability of mitochondria to meet the ATP demands of the human heart as well as skeletal muscle, namely ATP synthesis does not match the rate of ATP consumption. The presence of several cardiomyopathic phenotypes have been described in BTHS, including dilated cardiomyopathy, left ventricular noncompaction, either alone or in conjunction with other cardiomyopathic phenotypes, endocardial fibroelastosis, hypertrophic cardiomyopathy, and an apical form of hypertrophic cardiomyopathy, among others, all of which can be directly attributed to the lack of CL synthesis, remodeling, and maturation with subsequent mitochondrial dysfunction. Several mechanisms by which these cardiomyopathic phenotypes exist have been proposed, thereby identifying potential targets for treatment. Dysfunction of the sarcoplasmic reticulum Ca2+-ATPase pump and inflammation potentially triggered by circulating mitochondrial components have been identified. Currently, treatment modalities are aimed at addressing symptomatology of HF in BTHS, but do not address the underlying pathology. One novel therapeutic approach includes elamipretide, which crosses the mitochondrial outer membrane to localize to the inner membrane where it associates with cardiolipin to enhance ATP synthesis in several organs, including the heart. Encouraging clinical results of the use of elamipretide in treating patients with BTHS support the potential use of this drug for management of this rare disease.
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Affiliation(s)
- Hani N Sabbah
- Department of Medicine, Division of Cardiovascular Medicine, Henry Ford Hospital, Henry Ford Health System, 2799 West Grand Boulevard, Detroit, MI, 48202, USA.
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16
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Barth syndrome: cardiolipin, cellular pathophysiology, management, and novel therapeutic targets. Mol Cell Biochem 2021; 476:1605-1629. [PMID: 33415565 DOI: 10.1007/s11010-020-04021-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022]
Abstract
Barth syndrome is a rare X-linked genetic disease classically characterized by cardiomyopathy, skeletal myopathy, growth retardation, neutropenia, and 3-methylglutaconic aciduria. It is caused by mutations in the tafazzin gene localized to chromosome Xq28.12. Mutations in tafazzin may result in alterations in the level and molecular composition of the mitochondrial phospholipid cardiolipin and result in large elevations in the lysophospholipid monolysocardiolipin. The increased monolysocardiolipin:cardiolipin ratio in blood is diagnostic for the disease, and it leads to disruption in mitochondrial bioenergetics. In this review, we discuss cardiolipin structure, synthesis, and function and provide an overview of the clinical and cellular pathophysiology of Barth Syndrome. We highlight known pharmacological management for treatment of the major pathological features associated with the disease. In addition, we discuss non-pharmacological management. Finally, we highlight the most recent promising therapeutic options for this rare mitochondrial disease including lipid replacement therapy, peroxisome proliferator-activated receptor agonists, tafazzin gene replacement therapy, induced pluripotent stem cells, mitochondria-targeted antioxidants and peptides, and the polyphenolic compound resveratrol.
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Abstract
The term diabetic cardiomyopathy is defined as the presence of abnormalities in myocardial structure and function that occur in the absence of, or in addition to, well-established cardiovascular risk factors. A key contributor to this abnormal structural-functional relation is the complex interplay of myocardial metabolic remodeling, defined as the loss the flexibility in myocardial substrate metabolism and its downstream detrimental effects, such as mitochondrial dysfunction, inflammation, and fibrosis. In parallel with the growth in understanding of these biological underpinnings has been developmental advances in imaging tools such as positron emission tomography and magnetic resonance imaging and spectroscopy that permit the detection and in many cases quantification, of the processes that typifies the myocardial metabolic remodeling in diabetic cardiomyopathy. The imaging readouts can be obtained in both preclinical models of diabetes mellitus and patients with diabetes mellitus facilitating the bi-directional movement of information between bench and bedside. Moreover, imaging biomarkers provided by these tools are now being used to enhance discovery and development of therapies designed to reduce the myocardial effects of diabetes mellitus through metabolic modulation. In this review, the use of these imaging tools in the patient with diabetes mellitus from a mechanistic, therapeutic effect, and clinical management perspective will be discussed.
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Affiliation(s)
- Linda R Peterson
- From the Cardiovascular Division, Department of Medicine (L.R.P.), Washington University School of Medicine, St Louis, MO
| | - Robert J Gropler
- Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology (R.J.G.), Washington University School of Medicine, St Louis, MO
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18
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Ren M, Miller PC, Schlame M, Phoon CKL. A critical appraisal of the tafazzin knockdown mouse model of Barth syndrome: what have we learned about pathogenesis and potential treatments? Am J Physiol Heart Circ Physiol 2019; 317:H1183-H1193. [PMID: 31603701 DOI: 10.1152/ajpheart.00504.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pediatric heart failure remains poorly understood, distinct in many aspects from adult heart failure. Limited data point to roles of altered mitochondrial functioning and, in particular, changes in mitochondrial lipids, especially cardiolipin. Barth syndrome is a mitochondrial disorder caused by tafazzin mutations that lead to abnormal cardiolipin profiles. Patients are afflicted by cardiomyopathy, skeletal myopathy, neutropenia, and growth delay. A mouse model of Barth syndrome was developed a decade ago, which relies on a doxycycline-inducible short hairpin RNA to knock down expression of tafazzin mRNA (TAZKD). Our objective was to review published data from the TAZKD mouse to determine its contributions to our pathogenetic understanding of, and potential treatment strategies for, Barth syndrome. In regard to the clinical syndrome, the reported physiological, biochemical, and ultrastructural abnormalities of the mouse model mirror those in Barth patients. Using this model, the peroxisome proliferator-activated receptor pan-agonist bezafibrate has been suggested as potential therapy because it ameliorated the cardiomyopathy in TAZKD mice, while increasing mitochondrial biogenesis. A clinical trial is now underway to test bezafibrate in Barth syndrome patients. Thus the TAZKD mouse model of Barth syndrome has led to important insights into disease pathogenesis and therapeutic targets, which can potentially translate to pediatric heart failure.
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Affiliation(s)
- Mindong Ren
- Department of Anesthesiology, New York University School of Medicine, New York, New York.,Department of Cell Biology, New York University School of Medicine, New York, New York
| | - Paighton C Miller
- Department of Pediatrics, Division of Pediatric Cardiology, New York University School of Medicine, New York, New York
| | - Michael Schlame
- Department of Anesthesiology, New York University School of Medicine, New York, New York.,Department of Cell Biology, New York University School of Medicine, New York, New York
| | - Colin K L Phoon
- Department of Pediatrics, Division of Pediatric Cardiology, New York University School of Medicine, New York, New York
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19
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Suzuki-Hatano S, Sriramvenugopal M, Ramanathan M, Soustek M, Byrne BJ, Cade WT, Kang PB, Pacak CA. Increased mtDNA Abundance and Improved Function in Human Barth Syndrome Patient Fibroblasts Following AAV- TAZ Gene Delivery. Int J Mol Sci 2019; 20:E3416. [PMID: 31336787 PMCID: PMC6678701 DOI: 10.3390/ijms20143416] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/29/2022] Open
Abstract
Barth syndrome (BTHS) is a rare, X-linked, mitochondrial disorder caused by mutations in the gene encoding tafazzin. BTHS results in cardiomyopathy, muscle fatigue, and neutropenia in patients. Tafazzin is responsible for remodeling cardiolipin, a key structural lipid of the inner mitochondrial membrane. As symptoms can vary in severity amongst BTHS patients, we sought to compare mtDNA copy numbers, mitochondrial fragmentation, and functional parameters between primary dermal BTHS fibroblasts isolated from patients with two different mutations in the TAZ locus. To confirm cause‒effect relationships and further support the development of gene therapy for BTHS, we also characterized the BTHS cells following adeno-associated virus (AAV)-TAZ transduction. Our data show that, in response to AAV-TAZ transduction, these remarkably dynamic organelles show recovery of mtDNA copy numbers, mitochondrial structure, and mitochondrial function, providing additional evidence to support the therapeutic potential of AAV-mediated gene delivery for BTHS. This study also demonstrates the direct relationship between healthy mitochondrial membrane structure and maintenance of proper levels of mtDNA copy numbers.
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Affiliation(s)
- Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mughil Sriramvenugopal
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Manash Ramanathan
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Meghan Soustek
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Peter B Kang
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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20
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Li Y, Lou W, Raja V, Denis S, Yu W, Schmidtke MW, Reynolds CA, Schlame M, Houtkooper RH, Greenberg ML. Cardiolipin-induced activation of pyruvate dehydrogenase links mitochondrial lipid biosynthesis to TCA cycle function. J Biol Chem 2019; 294:11568-11578. [PMID: 31186346 DOI: 10.1074/jbc.ra119.009037] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 05/22/2019] [Indexed: 12/17/2022] Open
Abstract
Cardiolipin (CL) is the signature phospholipid of mitochondrial membranes. Although it has long been known that CL plays an important role in mitochondrial bioenergetics, recent evidence in the yeast model indicates that CL is also essential for intermediary metabolism. To gain insight into the function of CL in energy metabolism in mammalian cells, here we analyzed the metabolic flux of [U-13C]glucose in a mouse C2C12 myoblast cell line, TAZ-KO, which is CL-deficient because of CRISPR/Cas9-mediated knockout of the CL-remodeling enzyme tafazzin (TAZ). TAZ-KO cells exhibited decreased flux of [U-13C]glucose to [13C]acetyl-CoA and M2 and M4 isotopomers of tricarboxylic acid (TCA) cycle intermediates. The activity of pyruvate carboxylase, the predominant enzyme for anaplerotic replenishing of the TCA cycle, was elevated in TAZ-KO cells, which also exhibited increased sensitivity to the pyruvate carboxylase inhibitor phenylacetate. We attributed a decreased carbon flux from glucose to acetyl-CoA in the TAZ-KO cells to a ∼50% decrease in pyruvate dehydrogenase (PDH) activity, which was observed in both TAZ-KO cells and cardiac tissue from TAZ-KO mice. Protein-lipid overlay experiments revealed that PDH binds to CL, and supplementing digitonin-solubilized TAZ-KO mitochondria with CL restored PDH activity to WT levels. Mitochondria from TAZ-KO cells exhibited an increase in phosphorylated PDH, levels of which were reduced in the presence of supplemented CL. These findings indicate that CL is required for optimal PDH activation, generation of acetyl-CoA, and TCA cycle function, findings that link the key mitochondrial lipid CL to TCA cycle function and energy metabolism.
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Affiliation(s)
- Yiran Li
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Wenjia Lou
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Vaishnavi Raja
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Simone Denis
- Laboratory of Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Amsterdam Gastroenterology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wenxi Yu
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Christian A Reynolds
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
| | - Michael Schlame
- Department of Anesthesiology, New York University School of Medicine, New York 10016, New York.,Department of Cell Biology, New York University School of Medicine, New York 10016, New York
| | - Riekelt H Houtkooper
- Laboratory of Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Amsterdam Gastroenterology and Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit Michigan 48202
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21
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Finsterer J. Barth syndrome: mechanisms and management. APPLICATION OF CLINICAL GENETICS 2019; 12:95-106. [PMID: 31239752 PMCID: PMC6558240 DOI: 10.2147/tacg.s171481] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/04/2019] [Indexed: 12/21/2022]
Abstract
Objectives: Barth syndrome is an ultra-rare, infantile-onset, X-linked recessive mitochondrial disorder, primarily affecting males, due to variants in TAZ encoding for the cardiolipin transacylase tafazzin. This review aimed to summarize and discuss recent and earlier findings concerning the etiology, pathogenesis, clinical presentation, diagnosis, treatment, and outcome of Barth syndrome. Method: A literature review was undertaken through a MEDLINE search. Results: The phenotype of Barth syndrome is highly variable but most frequently patients present with hypertrophic/dilated/non-compaction cardiomyopathy, fibroelastosis, arrhythmias, neutropenia, mitochondrial myopathy, growth retardation, dysmorphism, cognitive impairment, and other, rarer features. Lactic acid and creatine kinase, and blood and urine organic acids, particularly 3-methylglutaconic acid and monolysocardiolipin, are often elevated. Cardiolipin is decreased. Biochemical investigations may show decreased activity of various respiratory chain complexes. The diagnosis is confirmed by documentation of a causative TAZ variant. Treatment is symptomatic and directed toward treating heart failure, arrhythmias, neutropenia, and mitochondrial myopathy. Conclusions: Although Barth syndrome is still an orphan disease, with fewer than 200 cases described so far, there is extensive ongoing research with regard to its pathomechanism and new therapeutic approaches. Although most of these approaches are still experimental, it can be expected that causative strategies will be developed in the near future.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, Austria
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22
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Cade WT, Bohnert KL, Peterson LR, Patterson BW, Bittel AJ, Okunade AL, de las Fuentes L, Steger-May K, Bashir A, Schweitzer GG, Chacko SK, Wanders RJ, Pacak CA, Byrne BJ, Reeds DN. Blunted fat oxidation upon submaximal exercise is partially compensated by enhanced glucose metabolism in children, adolescents, and young adults with Barth syndrome. J Inherit Metab Dis 2019; 42:480-493. [PMID: 30924938 PMCID: PMC6483838 DOI: 10.1002/jimd.12094] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/27/2019] [Indexed: 12/26/2022]
Abstract
Barth syndrome (BTHS) is a rare X-linked condition resulting in abnormal mitochondria, cardioskeletal myopathy, and growth delay; however, the effects of BTHS on substrate metabolism regulation and their relationships with tissue function in humans are unknown. We sought to characterize glucose and fat metabolism during rest, submaximal exercise, and postexercise rest in children, adolescents, and young adults with BTHS and unaffected controls and examine their relationships with cardioskeletal energetics and function. Children/adolescents and young adults with BTHS (n = 29) and children/adolescent and young adult control participants (n = 28, total n = 57) underwent an infusion of 6'6'H2 glucose and U-13 C palmitate and indirect calorimetry during rest, 30-minutes of moderate exercise (50% V˙O2peak ), and recovery. Cardiac function, cardioskeletal mitochondrial energetics, and exercise capacity were examined via echocardiography, 31 P magnetic resonance spectroscopy, and peak exercise testing, respectively. The glucose turnover rate was significantly higher in individuals with BTHS during rest (33.2 ± 9.8 vs 27.2 ± 8.1 μmol/kgFFM/min, P < .01) and exercise (34.7 ± 11.2 vs 29.5 ± 8.8 μmol/kgFFM/min, P < .05) and tended to be higher postexercise (33.7 ± 10.2 vs 28.8 ± 8.0 μmol/kgFFM/min, P < .06) compared to controls. Increases in total fat (-3.9 ± 7.5 vs 10.5 ± 8.4 μmol/kgFFM/min, P < .0001) and plasma fatty acid oxidation rates (0.0 ± 1.8 vs 5.1 ± 3.9 μmol/kgFFM/min, P < .0001) from rest to exercise were severely blunted in BTHS compared to controls. Conclusion: An inability to upregulate fat metabolism during moderate intensity exercise appears to be partially compensated by elevations in glucose metabolism. Derangements in fat and glucose metabolism are characteristic of the pathophysiology of BTHS. A severely blunted ability to upregulate fat metabolism during a modest level of physical activity is a defining pathophysiologic characteristic in children, adolescents, and young adults with BTHS.
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Affiliation(s)
- W. Todd Cade
- Program in Physical Therapy, 4444 Forest Park Avenue, Washington University School of Medicine, St. Louis, MO
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Kathryn L. Bohnert
- Program in Physical Therapy, 4444 Forest Park Avenue, Washington University School of Medicine, St. Louis, MO
| | - Linda R. Peterson
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Bruce W. Patterson
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Adam J. Bittel
- Program in Physical Therapy, 4444 Forest Park Avenue, Washington University School of Medicine, St. Louis, MO
| | - Adewole L. Okunade
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Lisa de las Fuentes
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Karen Steger-May
- Division of Biostatistics, Washington University School of Medicine, St. Louis, MO
| | - Adil Bashir
- Department of Radiology, Washington University School of Medicine, St. Louis, MO
- Department of Electrical and Computer Engineering, Auburn University, Auburn, AL
| | | | - Shaji K. Chacko
- Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Ronald J. Wanders
- Department of Pediatrics, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Barry J Byrne
- Department of Pediatrics, University of Florida, Gainesville, FL
| | - Dominic N. Reeds
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
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23
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Semba RD, Moaddel R, Zhang P, Ramsden CE, Ferrucci L. Tetra-linoleoyl cardiolipin depletion plays a major role in the pathogenesis of sarcopenia. Med Hypotheses 2019; 127:142-149. [PMID: 31088638 DOI: 10.1016/j.mehy.2019.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 04/16/2019] [Indexed: 12/25/2022]
Abstract
Sarcopenia, the progressive loss of muscle mass, strength, and physical performance that occurs during aging, is highly prevalent among the elderly. Sarcopenia increases the risk of falls, disability, and death. The biological basis for sarcopenia is not well understood. There are no specific preventive or therapeutic strategies for sarcopenia except exercise. The elucidation of biological pathways and identification of therapeutic targets for treating or preventing sarcopenia remain a high priority in aging research. Mitochondria play a critical role in skeletal muscle by providing energy in the form of ATP, regulation of signaling, calcium homeostasis, autophagy, and other functions. Cardiolipin, a unique dimeric phospholipid specific to mitochondria and an essential component of mitochondrial membranes, is involved in mitochondrial protein transport, maintaining structural organization of mitochondrial membranes, cellular signaling, regulating enzymes involved in β-oxidation of fatty acids, and facilitating normal electron transport chain (ETC) function and generation of ATP. The fatty acid species composition of cardiolipin is critical to mitochondrial bioenergetics, as cardiolipin affects membrane biophysical properties, binds and stabilizes ETC protein complexes, and shapes the curvature of the mitochondrial cristae. Tetra-linoleoyl cardiolipin (18:2)4 comprises ∼80% of cardiolipin in mitochondria in normal human skeletal and cardiac muscle and is optimal for effective ETC function and ATP generation. Aging is associated with a decrease in cardiolipin content, decrease in tetra-linoleoyl cardiolipin (18:2)4 and replacement of linoleic acid (18:2) with other fatty acids in cardiolipin composition, decline of ETC function, and increased generation of reactive oxygen species in muscle. Together, these findings from the literature prompt the hypothesis that depletion of the cardiolipin (18:2)4 species may be at the root of mitochondrial dysfunction with aging, in turn leading to sarcopenia. Corroboration of the tetra-linoleoyl cardiolipin depletion hypothesis suggests new leads for the prevention and treatment of sarcopenia by enhancing the biosynthesis, accretion, and integrity of tetra-linoleoyl cardiolipin.
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Affiliation(s)
- Richard D Semba
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Ruin Moaddel
- National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Pingbo Zhang
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Christopher E Ramsden
- National Institute on Aging, National Institutes of Health, Baltimore, MD, United States; National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, United States
| | - Luigi Ferrucci
- National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
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24
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Suzuki-Hatano S, Saha M, Soustek MS, Kang PB, Byrne BJ, Cade WT, Pacak CA. AAV9- TAZ Gene Replacement Ameliorates Cardiac TMT Proteomic Profiles in a Mouse Model of Barth Syndrome. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:167-179. [PMID: 30788385 PMCID: PMC6369239 DOI: 10.1016/j.omtm.2019.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/16/2019] [Indexed: 12/23/2022]
Abstract
Barth syndrome (BTHS) is a rare mitochondrial disease that causes severe cardiomyopathy and has no disease-modifying therapy. It is caused by recessive mutations in the gene tafazzin (TAZ), which encodes tafazzin-an acyltransferase that remodels the inner mitochondrial membrane lipid cardiolipin. To identify novel mechanistic pathways involved in BTHS and evaluate the effects of gene therapy on proteomic profiles, we performed a multiplex tandem mass tagging (TMT) quantitative proteomics analysis to compare protein expression profiles from heart lysates isolated from BTHS, healthy wild-type (WT), and BTHS treated with adeno-associated virus serotype 9 (AAV9)-TAZ gene replacement as neonates or adults. 197 proteins with ≥2 unique peptides were identified. Of these, 91 proteins were significantly differentially expressed in BTHS compared to WT controls. Cause-effect relationships between tafazzin deficiency and altered protein profiles were confirmed through demonstrated significant improvements in expression levels following administration of AAV9-TAZ. The importance of TMEM65 in Cx43 localization to cardiac intercalated discs was revealed as a novel consequence of tafazzin deficiency that was improved following gene therapy. This study identifies novel mechanistic pathways involved in the pathophysiology of BTHS, demonstrates the ability of gene delivery to improve protein expression profiles, and provides support for clinical translation of AAV9-TAZ gene therapy.
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Affiliation(s)
- Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Madhurima Saha
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Meghan S Soustek
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Peter B Kang
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
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25
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Suzuki-Hatano S, Saha M, Rizzo SA, Witko RL, Gosiker BJ, Ramanathan M, Soustek MS, Jones MD, Kang PB, Byrne BJ, Cade WT, Pacak CA. AAV-Mediated TAZ Gene Replacement Restores Mitochondrial and Cardioskeletal Function in Barth Syndrome. Hum Gene Ther 2018; 30:139-154. [PMID: 30070157 DOI: 10.1089/hum.2018.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Barth syndrome (BTHS) is a rare mitochondrial disease that affects heart and skeletal muscle and has no curative treatment. It is caused by recessive mutations in the X-linked gene TAZ, which encodes tafazzin. To develop a clinically relevant gene therapy to restore tafazzin function and treat BTHS, three different adeno-associated virus serotype 9 vectors were tested and compared to identify the optimal promoter-cytomegalovirus (CMV), desmin (Des), or a native tafazzin promoter (Taz)-for TAZ expression following intravenous administration of 1 × 1013 vector genomes/kilogram to a mouse model of BTHS as either neonates (1-2 days of age) or adults (3 months of age). At 5 months of age, evaluations of biodistribution and TAZ expression levels, mouse activity assessments, fatigue in response to exercise, muscle strength, cardiac function, mitochondrial structure, oxygen consumption, and electron transport chain complex activity assays were performed to measure the extent of improvement in treated mice. Each promoter was scored for significant improvement over untreated control mice and significant improvement compared with the other two promoters for every measurement and within each age of administration. All three of the promoters resulted in significant improvements in a majority of the assessments compared with untreated BTHS controls. When scored for overall effectiveness as a gene therapy, the Des promoter was found to provide improvement in the most assessments, followed by the CMV promoter, and finally Taz regardless of injection age. This study provides substantial support for translation of an adeno-associated virus serotype 9-mediated TAZ gene replacement strategy using a Des promoter for human BTHS patients in the clinic.
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Affiliation(s)
- Silveli Suzuki-Hatano
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Madhurima Saha
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Skylar A Rizzo
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Rachael L Witko
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Bennett J Gosiker
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Manashwi Ramanathan
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Meghan S Soustek
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - Michael D Jones
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - Barry J Byrne
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - W Todd Cade
- 3 Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
| | - Christina A Pacak
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
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26
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Ren J, Shang T, Sherry AD, Malloy CR. Unveiling a hidden 31 P signal coresonating with extracellular inorganic phosphate by outer-volume-suppression and localized 31 P MRS in the human brain at 7T. Magn Reson Med 2018; 80:1289-1297. [PMID: 29427295 PMCID: PMC6085175 DOI: 10.1002/mrm.27121] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/22/2017] [Accepted: 01/15/2018] [Indexed: 01/19/2023]
Abstract
PURPOSE The study was undertaken to demonstrate that there is more than 1 component in the extracellular Pi31 P signal ( Piex) acquired from human head using nonlocalized 31 P MRS. METHODS Outer-volume-suppression (OVS) saturation and 1D/2D 31 P CSI were utilized to reveal the presence of an additional component in the Piex signal. RESULTS 67% of the head extracellular Pi signal was attenuated upon OVS saturation of the peripheral meningeal tissues, likely reflecting elimination of the Pi signal in the meningeal fluids (the blood and CSF). Localized 1D/2D CSI data provided further support for this assignment. Upon correction for the meningeal contribution, the extracellular Pi concentration was 0.51 ± 0.07 mM, whereas the intracellular Pi was 0.85 ± 0.10 mM. The extracellular pH was measured as 7.32 ± 0.04 when using OVS, as compared to 7.39 ± 0.03 when measured without OVS (N = 7 subjects). CONCLUSION The extracellular Pi signal acquired from the human head using nonlocalized 31 P MRS contains a significant component likely contributed by peripheral blood and CSF in meninges that must be removed in order to use this signal as an endogenous probe for measuring extracellular pH and other properties in the brain.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ty Shang
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080
| | - Craig R. Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
- VA North Texas Health Care System, Dallas, TX 75216
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Bashir A, Bohnert KL, Reeds DN, Peterson LR, Bittel AJ, de Las Fuentes L, Pacak CA, Byrne BJ, Cade WT. Impaired cardiac and skeletal muscle bioenergetics in children, adolescents, and young adults with Barth syndrome. Physiol Rep 2018; 5:5/3/e13130. [PMID: 28196853 PMCID: PMC5309577 DOI: 10.14814/phy2.13130] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 11/24/2022] Open
Abstract
Barth syndrome (BTHS) is an X‐linked condition characterized by altered cardiolipin metabolism and cardioskeletal myopathy. We sought to compare cardiac and skeletal muscle bioenergetics in children, adolescents, and young adults with BTHS and unaffected controls and examine their relationships with cardiac function and exercise capacity. Children/adolescents and young adults with BTHS (n = 20) and children/adolescent and young adult control participants (n = 23, total n = 43) underwent 31P magnetic resonance spectroscopy (31P‐MRS) of the lower extremity (calf) and heart for estimation of skeletal muscle and cardiac bioenergetics. Peak exercise testing (VO2peak) and resting echocardiography were also performed on all participants. Cardiac PCr/ATP ratio was significantly lower in children/adolescents (BTHS: 1.5 ± 0.2 vs. Control: 2.0 ± 0.3, P < 0.01) and adults (BTHS: 1.9 ± 0.2 vs. Control: 2.3 ± 0.2, P < 0.01) with BTHS compared to Control groups. Adults (BTHS: 76.4 ± 31.6 vs. Control: 35.0 ± 7.4 sec, P < 0.01) and children/adolescents (BTHS: 71.5 ± 21.3 vs. Control: 31.4 ± 7.4 sec, P < 0.01) with BTHS had significantly longer calf PCr recovery (τPCr) postexercise compared to controls. Maximal calf ATP production through oxidative phosphorylation (Qmax‐lin) was significantly lower in children/adolescents (BTHS: 0.5 ± 0.1 vs. Control: 1.1 ± 0.3 mmol/L per sec, P < 0.01) and adults (BTHS: 0.5 ± 0.2 vs. Control: 1.0 ± 0.2 mmol/L sec, P < 0.01) with BTHS compared to controls. Blunted cardiac and skeletal muscle bioenergetics were associated with lower VO2peak but not resting cardiac function. Cardiac and skeletal muscle bioenergetics are impaired and appear to contribute to exercise intolerance in BTHS.
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Affiliation(s)
- Adil Bashir
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri.,Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama
| | - Kathryn L Bohnert
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
| | - Dominic N Reeds
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Linda R Peterson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Adam J Bittel
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
| | - Lisa de Las Fuentes
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Christina A Pacak
- Department of Pediatrics, University of Florida, Gainesville, Florida
| | - Barry J Byrne
- Department of Pediatrics, University of Florida, Gainesville, Florida
| | - W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri .,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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Cade WT, Bohnert KL, Reeds DN, Peterson LR, Bittel AJ, Bashir A, Byrne BJ, Taylor CL. Peak oxygen uptake (VO2peak) across childhood, adolescence and young adulthood in Barth syndrome: Data from cross-sectional and longitudinal studies. PLoS One 2018; 13:e0197776. [PMID: 29795646 PMCID: PMC5967725 DOI: 10.1371/journal.pone.0197776] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/04/2018] [Indexed: 11/19/2022] Open
Abstract
Barth syndrome (BTHS) is an ultra-rare, X-linked recessive disorder characterized by cardio-skeletal myopathy, exercise intolerance, and growth delay. Oxygen uptake during peak exercise (VO2peak) has been shown to be severely limited in individuals with BTHS however; the trajectory of VO2peak from childhood to young adulthood is unknown. The objective of this study was to describe VO2peak from childhood through young adulthood in BTHS. METHODS AND MATERIALS VO2peak over time was presented through cross-sectional (n = 33 participants) and a longitudinal analyses (n = 12 participants). Retrospective data were obtained through maximal exercise testing on a cycle ergometer from individuals with BTHS who were or are currently enrolled in a research study during July 2006-September 2017. Participants included in the cross-sectional analysis were divided into 3 groups for analysis: 1) children (n = 13), 2) adolescents (n = 8), and 3) young adults (n = 12). Participants in the longitudinal analysis had at least two exercise tests over a span of 2-9 years. RESULTS VO2peak relative to body weight (ml/kgBW/min), fat-free mass (FFM) and by percent of predicted VO2peak obtained were not significantly different between children, adolescents and young adults. VO2peak did not longitudinally change over a mean time of ~5 years in late adolescent and young adult participants with repeated tests. A model including both cardiac and skeletal muscle variables best predicted VO2peak. CONCLUSIONS In conclusion, VO2peak relative to body weight and fat-free mass demonstrates short- and long-term stability from childhood to young adulthood in BTHS with some variability among individuals.
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Affiliation(s)
- William Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Kathryn L. Bohnert
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Dominic N. Reeds
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Linda R. Peterson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Adam J. Bittel
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Adil Bashir
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, United States of America
| | - Barry J. Byrne
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States of America
| | - Carolyn L. Taylor
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, United States of America
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Bittel AJ, Bohnert KL, Reeds DN, Peterson LR, de Las Fuentes L, Corti M, Taylor CL, Byrne BJ, Cade WT. Reduced Muscle Strength in Barth Syndrome May Be Improved by Resistance Exercise Training: A Pilot Study. JIMD Rep 2018; 41:63-72. [PMID: 29654548 DOI: 10.1007/8904_2018_102] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 01/17/2018] [Accepted: 01/17/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Cardioskeletal myopathy is thought to contribute to exercise intolerance, and reduced quality of life (QOL) in Barth syndrome (BTHS). The objectives of this study were to examine: (1) skeletal muscle strength/performance in adolescents and young adults with BTHS and (2) the safety, feasibility, and initial efficacy of 12 weeks of progressive resistance exercise training (RET) on muscle strength, mass, and performance, bone mineral density, exercise tolerance, cardiac function, and QOL in individuals with BTHS. METHODS Individuals with BTHS (n = 9, 23 ± 6 years), and age-, sex-, and activity level-matched unaffected Controls (n = 7, 26 ± 5 years) underwent baseline testing to assess muscle performance, exercise capacity, cardiac structure and function, body composition, and health-related QOL. Subsequently, n = 3 participants with BTHS performed 12 weeks of supervised RET (60 min per session, 3 sessions/week). All testing was repeated post-RET. RESULTS BTHS had lower strength and lean muscle mass compared to Controls (all p < 0.05). BTHS also had diminished lower extremity, upper extremity, thoracic spine, lumbar spine, and pelvic bone mineral density (all p < 0.05) and reduced exercise capacity (p < 0.001) compared to Controls. RET was well-tolerated and attended, was not associated with any adverse events, and significantly increased muscle strength (p < 0.05). CONCLUSIONS Individuals with BTHS demonstrate reduced muscle strength and mass, bone mineral density, and exercise capacity. RET appears safe and well-tolerated in BTHS and promotes increased muscle strength. Larger studies are needed to confirm these improvements and to fully determine the effects of RET in individuals with BTHS.
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Affiliation(s)
- Adam J Bittel
- 13Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO USA
| | - Kathryn L Bohnert
- 13Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO USA
| | - Dominic N Reeds
- 14Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
| | - Linda R Peterson
- 14Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
| | - Lisa de Las Fuentes
- 14Department of Medicine, Washington University School of Medicine, St. Louis, MO USA
| | - Manuela Corti
- 15Department of Pediatrics, University of Florida School of Medicine, Gainesville, FL USA
| | - Carolyn L Taylor
- 16Division of Cardiology, Medical University of South Carolina, Charleston, SC USA
| | - Barry J Byrne
- 15Department of Pediatrics, University of Florida School of Medicine, Gainesville, FL USA
| | - W Todd Cade
- 13Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO USA
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Damschroder D, Reynolds C, Wessells R. Drosophila tafazzin mutants have impaired exercise capacity. Physiol Rep 2018; 6:e13604. [PMID: 29405656 PMCID: PMC5800294 DOI: 10.14814/phy2.13604] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/02/2018] [Accepted: 01/09/2018] [Indexed: 11/26/2022] Open
Abstract
Cardiolipin (CL) is a mitochondrial phospholipid that helps maintain normal structure of the inner mitochondrial membrane and stabilize the protein complexes of the electron transport chain to promote efficient ATP synthesis. Tafazzin, an acyl-transferase, is required for synthesis of the mature form of CL. Mutations in the tafazzin (TAZ) gene are associated with a human disorder known as Barth syndrome. Symptoms of Barth syndrome often include muscle weakness and exercise intolerance. Previous work demonstrates that Drosophila Taz mutants exhibit motor weakness, as measured by reduced flying and climbing abilities. However, Drosophila TAZ mutants' baseline endurance or response to endurance exercise training has not been assessed. Here, we find that TAZ mutants have reduced endurance and do not improve following a stereotypical exercise training paradigm, indicating that loss of TAZ function leads to exercise intolerance in Drosophila. Although cardiac phenotypes are observed in human Barth syndrome patients, TAZ mutants had normal resistance to cardiac pacing. In the future, endurance may be a useful screening tool to identify additional genetic modifiers of tafazzin.
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Affiliation(s)
- Deena Damschroder
- Deparment of PhysiologyWayne State University School of MedicineDetroitMichigan
| | - Christian Reynolds
- Department of Emergency MedicineWayne State University School of MedicineDetroitMichigan
| | - Robert Wessells
- Deparment of PhysiologyWayne State University School of MedicineDetroitMichigan
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Baati N, Feillet-Coudray C, Fouret G, Vernus B, Goustard B, Coudray C, Lecomte J, Blanquet V, Magnol L, Bonnieu A, Koechlin-Ramonatxo C. Myostatin deficiency is associated with lipidomic abnormalities in skeletal muscles. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1044-1055. [DOI: 10.1016/j.bbalip.2017.06.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 06/19/2017] [Accepted: 06/29/2017] [Indexed: 11/16/2022]
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