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Borrelli F, Lombardi R, Canciello G, Frisso G, Todde G, Esposito G, Losi MA. Mechano-energetic efficiency in patients with hypertrophic cardiomyopathy with and without sarcomeric mutations. J Cardiovasc Transl Res 2024; 17:458-466. [PMID: 37833437 DOI: 10.1007/s12265-023-10441-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/18/2023] [Indexed: 10/15/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is mainly caused by sarcomeric mutations which may affect myocardial mechano-energetic efficiency (MEE). We investigated the effects of sarcomeric mutations on MEE. A non-invasive pressure/volume (P/V) analysis was performed. We included 49 genetically screened HCM patients. MEEi was calculated as the ratio between stroke volume and heart rate normalized by LV mass. Fifty-seven percent (57%) HCM patients carried a sarcomeric mutation. Patients with and without sarcomeric mutations had similar LV ejection fraction, heart rate, LV mass, and LV outflow gradient. Younger age at diagnosis, family history of HCM, and lower MEEi were associated with presence of sarcomeric mutation (p = 0.017; p = 0.001 and p = 0.0001, respectively). Lower MEEi in HCM with sarcomeric mutation is not related to significant differences on filling pressure as shown on P/V analysis. Sarcomeric mutations determine a reduction of the LV pump performance as estimated by MEEi in HCM. Lower MEEi may predict a positive genetic analysis.
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Affiliation(s)
- Felice Borrelli
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Raffaella Lombardi
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Grazia Canciello
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Giulia Frisso
- Department of Molecular Medicine and Medical Biotechnologies, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Gaetano Todde
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy
| | - Maria-Angela Losi
- Department of Advanced Biomedical Sciences, University Federico II of Naples, Via S Pansini, 5, I-801313, Naples, Italy.
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Coleman JA, Ashkir Z, Raman B, Bueno-Orovio A. Mechanisms and prognostic impact of myocardial ischaemia in hypertrophic cardiomyopathy. Int J Cardiovasc Imaging 2023; 39:1979-1996. [PMID: 37358707 PMCID: PMC10589194 DOI: 10.1007/s10554-023-02894-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/03/2023] [Indexed: 06/27/2023]
Abstract
Despite the progress made in risk stratification, sudden cardiac death and heart failure remain dreaded complications for hypertrophic cardiomyopathy (HCM) patients. Myocardial ischaemia is widely acknowledged as a contributor to cardiovascular events, but the assessment of ischaemia is not yet included in HCM clinical guidelines. This review aims to evaluate the HCM-specific pro-ischaemic mechanisms and the potential prognostic value of imaging for myocardial ischaemia in HCM. A literature review was performed using PubMed to identify studies with non-invasive imaging of ischaemia (cardiovascular magnetic resonance, echocardiography, and nuclear imaging) in HCM, prioritising studies published after the last major review in 2009. Other studies, including invasive ischaemia assessment and post-mortem histology, were also considered for mechanistic or prognostic relevance. Pro-ischaemic mechanisms in HCM reviewed included the effects of sarcomeric mutations, microvascular remodelling, hypertrophy, extravascular compressive forces and left ventricular outflow tract obstruction. The relationship between ischaemia and fibrosis was re-appraised by considering segment-wise analyses in multimodal imaging studies. The prognostic significance of myocardial ischaemia in HCM was evaluated using longitudinal studies with composite endpoints, and reports of ischaemia-arrhythmia associations were further considered. The high prevalence of ischaemia in HCM is explained by several micro- and macrostructural pathological features, alongside mutation-associated energetic impairment. Ischaemia on imaging identifies a subgroup of HCM patients at higher risk of adverse cardiovascular outcomes. Ischaemic HCM phenotypes are a high-risk subgroup associated with more advanced left ventricular remodelling, but further studies are required to evaluate the independent prognostic value of non-invasive imaging for ischaemia.
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Affiliation(s)
- James A Coleman
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Zakariye Ashkir
- Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Betty Raman
- Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, University of Oxford, Oxford, UK
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3
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Pioner JM, Vitale G, Steczina S, Langione M, Margara F, Santini L, Giardini F, Lazzeri E, Piroddi N, Scellini B, Palandri C, Schuldt M, Spinelli V, Girolami F, Mazzarotto F, van der Velden J, Cerbai E, Tesi C, Olivotto I, Bueno-Orovio A, Sacconi L, Coppini R, Ferrantini C, Regnier M, Poggesi C. Slower Calcium Handling Balances Faster Cross-Bridge Cycling in Human MYBPC3 HCM. Circ Res 2023; 132:628-644. [PMID: 36744470 PMCID: PMC9977265 DOI: 10.1161/circresaha.122.321956] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/19/2023] [Accepted: 01/24/2023] [Indexed: 02/07/2023]
Abstract
BACKGROUND The pathogenesis of MYBPC3-associated hypertrophic cardiomyopathy (HCM) is still unresolved. In our HCM patient cohort, a large and well-characterized population carrying the MYBPC3:c772G>A variant (p.Glu258Lys, E258K) provides the unique opportunity to study the basic mechanisms of MYBPC3-HCM with a comprehensive translational approach. METHODS We collected clinical and genetic data from 93 HCM patients carrying the MYBPC3:c772G>A variant. Functional perturbations were investigated using different biophysical techniques in left ventricular samples from 4 patients who underwent myectomy for refractory outflow obstruction, compared with samples from non-failing non-hypertrophic surgical patients and healthy donors. Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes and engineered heart tissues (EHTs) were also investigated. RESULTS Haplotype analysis revealed MYBPC3:c772G>A as a founder mutation in Tuscany. In ventricular myocardium, the mutation leads to reduced cMyBP-C (cardiac myosin binding protein-C) expression, supporting haploinsufficiency as the main primary disease mechanism. Mechanical studies in single myofibrils and permeabilized muscle strips highlighted faster cross-bridge cycling, and higher energy cost of tension generation. A novel approach based on tissue clearing and advanced optical microscopy supported the idea that the sarcomere energetics dysfunction is intrinsically related with the reduction in cMyBP-C. Studies in single cardiomyocytes (native and hiPSC-derived), intact trabeculae and hiPSC-EHTs revealed prolonged action potentials, slower Ca2+ transients and preserved twitch duration, suggesting that the slower excitation-contraction coupling counterbalanced the faster sarcomere kinetics. This conclusion was strengthened by in silico simulations. CONCLUSIONS HCM-related MYBPC3:c772G>A mutation invariably impairs sarcomere energetics and cross-bridge cycling. Compensatory electrophysiological changes (eg, reduced potassium channel expression) appear to preserve twitch contraction parameters, but may expose patients to greater arrhythmic propensity and disease progression. Therapeutic approaches correcting the primary sarcomeric defects may prevent secondary cardiomyocyte remodeling.
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Affiliation(s)
- Josè Manuel Pioner
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
- Department of Biology (J.M.P.), University of Florence, Italy
| | - Giulia Vitale
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
| | - Sonette Steczina
- Department of Bioengineering, University of Washington, Seattle, WA (S.S., M.R.)
| | - Marianna Langione
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
| | - Francesca Margara
- Department of Computer Science, University of Oxford, United Kingdom (F. Margara, A.B.-O.)
| | - Lorenzo Santini
- Department of NeuroFarBa (L. Santini, C. Palandri, V. Spinelli, E. Cerbai, R. Coppini), University of Florence, Italy
| | - Francesco Giardini
- European Laboratory for Non-Linear Spectroscopy (LENS) (F. Giardini, E. Lazzeri, C.F., C.P., E. Cerbai), University of Florence, Italy
| | - Erica Lazzeri
- European Laboratory for Non-Linear Spectroscopy (LENS) (F. Giardini, E. Lazzeri, C.F., C.P., E. Cerbai), University of Florence, Italy
| | - Nicoletta Piroddi
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
| | - Beatrice Scellini
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
| | - Chiara Palandri
- Department of NeuroFarBa (L. Santini, C. Palandri, V. Spinelli, E. Cerbai, R. Coppini), University of Florence, Italy
| | - Maike Schuldt
- Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Physiology, The Netherlands (M.S., J.v.d.V.)
| | - Valentina Spinelli
- Department of NeuroFarBa (L. Santini, C. Palandri, V. Spinelli, E. Cerbai, R. Coppini), University of Florence, Italy
| | - Francesca Girolami
- Pediatric Cardiology (F. Girolami), IRCCS Meyer Children’s Hospital, Florence, Italy
| | - Francesco Mazzarotto
- Department of Molecular and Translational Medicine, University of Brescia, Italy (F. Mazzarotto)
- National Heart and Lung Institute, Imperial College London, London, United Kingdom (F. Mazzarotto)
| | - Jolanda van der Velden
- Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Physiology, The Netherlands (M.S., J.v.d.V.)
| | - Elisabetta Cerbai
- Department of NeuroFarBa (L. Santini, C. Palandri, V. Spinelli, E. Cerbai, R. Coppini), University of Florence, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS) (F. Giardini, E. Lazzeri, C.F., C.P., E. Cerbai), University of Florence, Italy
| | - Chiara Tesi
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
| | - Iacopo Olivotto
- Cardiogenetics Unit (I.O.), IRCCS Meyer Children’s Hospital, Florence, Italy
- Referral Center for Cardiomyopathies, Careggi University Hospital, Florence, Italy (I.O.)
| | - Alfonso Bueno-Orovio
- Department of Computer Science, University of Oxford, United Kingdom (F. Margara, A.B.-O.)
| | - Leonardo Sacconi
- Institute of Clinical Physiology (IFC), National Research Council, Florence, Italy (L. Sacconi)
- Institute for Experimental Cardiovascular Medicine, Faculty of Medicine, University of Freiburg (L. Sacconi)
| | - Raffaele Coppini
- Department of NeuroFarBa (L. Santini, C. Palandri, V. Spinelli, E. Cerbai, R. Coppini), University of Florence, Italy
| | - Cecilia Ferrantini
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS) (F. Giardini, E. Lazzeri, C.F., C.P., E. Cerbai), University of Florence, Italy
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA (S.S., M.R.)
| | - Corrado Poggesi
- Department of Clinical and Experimental Medicine, Division of Physiology (J.M.P., G.V., M.L., N.P., B.S., C.T., C.F., C. Poggesi), University of Florence, Italy
- European Laboratory for Non-Linear Spectroscopy (LENS) (F. Giardini, E. Lazzeri, C.F., C.P., E. Cerbai), University of Florence, Italy
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4
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Zhang H, Guo Y, Kang J, He Y, Yang H, Sun Y, Fan L. A case of fetal isolated ventricular noncompaction with TNNT2 gene mutation and literature review. Echocardiography 2022; 39:1446-1449. [PMID: 36229763 DOI: 10.1111/echo.15433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/28/2022] [Accepted: 07/23/2022] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Ventricular noncompaction (VNC) is a cardiomyopathy characterized by overdeveloped ventricular trabeculaes and deep recess, which has been rarely reported. CASE PRESENTATION A 29-year-old Chinese pregnant woman with no obvious fetal abnormality in regular prenatal examination during first and second trimester. However, at 32 weeks of gestation, both obstetric growth scan and fetal echocardiogram revealed an enlarged heart with grid-like changes at the apical region. Eventually, the genetic and autopsy findings indicated the deceased infant with VNC. CONCLUSION Isolated VNC could be detected prenatally, even during the late pregnancy. Fetuses suspected of VNC should be offered genetic tests.
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Affiliation(s)
- Huijing Zhang
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
| | - Yongbing Guo
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
| | - Jinling Kang
- Department of Radiology, Decheng Maternal and Child Health Hospital, Dezhou, Shandong, 253036, China
| | - Yingdong He
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
| | - Huixia Yang
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
| | - Yu Sun
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
| | - Lixin Fan
- Department of Obstetrics and Gynecology, Peking University First Hospital, Beijing, 100034, China
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5
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Schuldt M, Pei J, Harakalova M, Dorsch LM, Schlossarek S, Mokry M, Knol JC, Pham TV, Schelfhorst T, Piersma SR, Dos Remedios C, Dalinghaus M, Michels M, Asselbergs FW, Moutin MJ, Carrier L, Jimenez CR, van der Velden J, Kuster DWD. Proteomic and Functional Studies Reveal Detyrosinated Tubulin as Treatment Target in Sarcomere Mutation-Induced Hypertrophic Cardiomyopathy. Circ Heart Fail 2021; 14:e007022. [PMID: 33430602 PMCID: PMC7819533 DOI: 10.1161/circheartfailure.120.007022] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Supplemental Digital Content is available in the text. Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. While ≈50% of patients with HCM carry a sarcomere gene mutation (sarcomere mutation-positive, HCMSMP), the genetic background is unknown in the other half of the patients (sarcomere mutation-negative, HCMSMN). Genotype-specific differences have been reported in cardiac function. Moreover, HCMSMN patients have later disease onset and a better prognosis than HCMSMP patients. To define if genotype-specific derailments at the protein level may explain the heterogeneity in disease development, we performed a proteomic analysis in cardiac tissue from a clinically well-phenotyped HCM patient group.
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Affiliation(s)
- Maike Schuldt
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physiology, Amsterdam Cardiovascular Sciences, The Netherlands (M.S., L.M.D., J.v.d.V., D.W.D.K.)
| | - Jiayi Pei
- Division Heart and Lungs, Department of Cardiology (J.P., M.H., F.W.A.), University Medical Center Utrecht, The Netherlands
| | - Magdalena Harakalova
- Division Heart and Lungs, Department of Cardiology (J.P., M.H., F.W.A.), University Medical Center Utrecht, The Netherlands
| | - Larissa M Dorsch
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physiology, Amsterdam Cardiovascular Sciences, The Netherlands (M.S., L.M.D., J.v.d.V., D.W.D.K.)
| | - Saskia Schlossarek
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Germany (S.S., L.C.).,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany (S.S., L.C.)
| | - Michal Mokry
- Department of Pediatric Gastroenterology, Wilhelmina Children's Hospital (M. Morky), University Medical Center Utrecht, The Netherlands
| | - Jaco C Knol
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Oncology, OncoProteomics Laboratory, VUmc-Cancer Center Amsterdam, The Netherlands (J.C.K., T.V.P., T.S., S.R.P., C.R.J.)
| | - Thang V Pham
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Oncology, OncoProteomics Laboratory, VUmc-Cancer Center Amsterdam, The Netherlands (J.C.K., T.V.P., T.S., S.R.P., C.R.J.)
| | - Tim Schelfhorst
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Oncology, OncoProteomics Laboratory, VUmc-Cancer Center Amsterdam, The Netherlands (J.C.K., T.V.P., T.S., S.R.P., C.R.J.)
| | - Sander R Piersma
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Oncology, OncoProteomics Laboratory, VUmc-Cancer Center Amsterdam, The Netherlands (J.C.K., T.V.P., T.S., S.R.P., C.R.J.)
| | - Cris Dos Remedios
- Sydney Heart Bank, Discipline of Anatomy, Bosch Institute, University of Sydney, Australia (C.d.R.)
| | - Michiel Dalinghaus
- Department of Pediatric Cardiology (M.D.), Erasmus Medical Center Rotterdam, The Netherlands
| | - Michelle Michels
- Department of Cardiology, Thorax Center (M. Michels), Erasmus Medical Center Rotterdam, The Netherlands
| | - Folkert W Asselbergs
- Division Heart and Lungs, Department of Cardiology (J.P., M.H., F.W.A.), University Medical Center Utrecht, The Netherlands.,Institute of Cardiovascular Science, Faculty of Population Health Sciences (F.W.A.), University College London, United Kingdom.,Health Data Research UK and Institute of Health Informatics (F.W.A.), University College London, United Kingdom
| | - Marie-Jo Moutin
- Grenoble Institut des Neurosciences (GIN), Université Grenoble Alpes, Grenoble, France (M.-J.M.)
| | - Lucie Carrier
- Institute of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, Germany (S.S., L.C.).,DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany (S.S., L.C.)
| | - Connie R Jimenez
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Oncology, OncoProteomics Laboratory, VUmc-Cancer Center Amsterdam, The Netherlands (J.C.K., T.V.P., T.S., S.R.P., C.R.J.)
| | - Jolanda van der Velden
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physiology, Amsterdam Cardiovascular Sciences, The Netherlands (M.S., L.M.D., J.v.d.V., D.W.D.K.)
| | - Diederik W D Kuster
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physiology, Amsterdam Cardiovascular Sciences, The Netherlands (M.S., L.M.D., J.v.d.V., D.W.D.K.)
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6
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Activation of Cannabinoid Receptors Attenuates Endothelin-1-Induced Mitochondrial Dysfunction in Rat Ventricular Myocytes. J Cardiovasc Pharmacol 2020; 75:54-63. [PMID: 31815823 PMCID: PMC6964873 DOI: 10.1097/fjc.0000000000000758] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Supplemental Digital Content is Available in the Text. Evidence suggests that the activation of the endocannabinoid system offers cardioprotection. Aberrant energy production by impaired mitochondria purportedly contributes to various aspects of cardiovascular disease. We investigated whether cannabinoid (CB) receptor activation would attenuate mitochondrial dysfunction induced by endothelin-1 (ET1). Acute exposure to ET1 (4 hours) in the presence of palmitate as primary energy substrate induced mitochondrial membrane depolarization and decreased mitochondrial bioenergetics and expression of genes related to fatty acid oxidation (ie, peroxisome proliferator–activated receptor-gamma coactivator-1α, a driver of mitochondrial biogenesis, and carnitine palmitoyltransferase-1β, facilitator of fatty acid uptake). A CB1/CB2 dual agonist with limited brain penetration, CB-13, corrected these parameters. AMP-activated protein kinase (AMPK), an important regulator of energy homeostasis, mediated the ability of CB-13 to rescue mitochondrial function. In fact, the ability of CB-13 to rescue fatty acid oxidation–related bioenergetics, as well as expression of proliferator-activated receptor-gamma coactivator-1α and carnitine palmitoyltransferase-1β, was abolished by pharmacological inhibition of AMPK using compound C and shRNA knockdown of AMPKα1/α2, respectively. Interventions that target CB/AMPK signaling might represent a novel therapeutic approach to address the multifactorial problem of cardiovascular disease.
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7
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The relation between sarcomere energetics and the rate of isometric tension relaxation in healthy and diseased cardiac muscle. J Muscle Res Cell Motil 2019; 42:47-57. [PMID: 31745760 PMCID: PMC7932984 DOI: 10.1007/s10974-019-09566-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/13/2019] [Indexed: 12/24/2022]
Abstract
Full muscle relaxation happens when [Ca2+] falls below the threshold for force activation. Several experimental models, from whole muscle organs and intact muscle down to skinned fibers, have been used to explore the cascade of kinetic events leading to mechanical relaxation. The use of single myofibrils together with fast solution switching techniques, has provided new information about the role of cross-bridge (CB) dissociation in the time course of isometric force decay. Myofibril’s relaxation is biphasic starting with a slow seemingly linear phase, with a rate constant, slow kREL, followed by a fast mono-exponential phase. Sarcomeres remain isometric during the slow force decay that reflects CB detachment under isometric conditions while the final fast relaxation phase begins with a sudden give of few sarcomeres and is then dominated by intersarcomere dynamics. Based on a simple two-state model of the CB cycle, myofibril slow kREL represents the apparent forward rate with which CBs leave force generating states (gapp) under isometric conditions and correlates with the energy cost of tension generation (ATPase/tension ratio); in short slow kREL ~ gapp ~ tension cost. The validation of this relationship is obtained by simultaneously measuring maximal isometric force and ATP consumption in skinned myocardial strips that provide an unambiguous determination of the relation between contractile and energetic properties of the sarcomere. Thus, combining kinetic experiments in isolated myofibrils and mechanical and energetic measurements in multicellular cardiac strips, we are able to provide direct evidence for a positive linear correlation between myofibril isometric relaxation kinetics (slow kREL) and the energy cost of force production both measured in preparations from the same cardiac sample. This correlation remains true among different types of muscles with different ATPase activities and also when CB kinetics are altered by cardiomyopathy-related mutations. Sarcomeric mutations associated to hypertrophic cardiomyopathy (HCM), a primary cardiac disorder caused by mutations in genes encoding sarcomeric proteins, have been often found to accelerate CB turnover rate and increase the energy cost of myocardial contraction. Here we review data showing that faster CB detachment results in a proportional increase in the energetic cost of tension generation in heart samples from both HCM patients and mouse models of the disease.
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8
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Yotti R, Seidman CE, Seidman JG. Advances in the Genetic Basis and Pathogenesis of Sarcomere Cardiomyopathies. Annu Rev Genomics Hum Genet 2019; 20:129-153. [PMID: 30978303 DOI: 10.1146/annurev-genom-083118-015306] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are common heart muscle disorders that are caused by pathogenic variants in sarcomere protein genes. HCM is characterized by unexplained cardiac hypertrophy (increased chamber wall thickness) that is accompanied by enhanced cardiac contractility and impaired relaxation. DCM is defined as increased ventricular chamber volume with contractile impairment. In this review, we discuss recent analyses that provide new insights into the molecular mechanisms that cause these conditions. HCM studies have uncovered the critical importance of conformational changes that occur during relaxation and enable energy conservation, which are frequently disturbed by HCM mutations. DCM studies have demonstrated the considerable prevalence of truncating variants in titin and have discerned that these variants reduce contractile function by impairing sarcomerogenesis. These new pathophysiologic mechanisms open exciting opportunities to identify new pharmacological targets and develop future cardioprotective strategies.
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Affiliation(s)
- Raquel Yotti
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; .,Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA; , .,Cardiovascular Division and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - Jonathan G Seidman
- Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA; ,
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9
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Piroddi N, Witjas-Paalberends ER, Ferrara C, Ferrantini C, Vitale G, Scellini B, Wijnker PJM, Sequiera V, Dooijes D, Dos Remedios C, Schlossarek S, Leung MC, Messer A, Ward DG, Biggeri A, Tesi C, Carrier L, Redwood CS, Marston SB, van der Velden J, Poggesi C. The homozygous K280N troponin T mutation alters cross-bridge kinetics and energetics in human HCM. J Gen Physiol 2018; 151:18-29. [PMID: 30578328 PMCID: PMC6314385 DOI: 10.1085/jgp.201812160] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/29/2018] [Indexed: 01/24/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, but the pathogenic mechanism is unclear. Piroddi et al. find impairment of cross-bridge kinetics and energetics in human sarcomeres with a TNNT2 mutation, suggesting that HCM involves inefficient ATP utilization. Hypertrophic cardiomyopathy (HCM) is a genetic form of left ventricular hypertrophy, primarily caused by mutations in sarcomere proteins. The cardiac remodeling that occurs as the disease develops can mask the pathogenic impact of the mutation. Here, to discriminate between mutation-induced and disease-related changes in myofilament function, we investigate the pathogenic mechanisms underlying HCM in a patient carrying a homozygous mutation (K280N) in the cardiac troponin T gene (TNNT2), which results in 100% mutant cardiac troponin T. We examine sarcomere mechanics and energetics in K280N-isolated myofibrils and demembranated muscle strips, before and after replacement of the endogenous troponin. We also compare these data to those of control preparations from donor hearts, aortic stenosis patients (LVHao), and HCM patients negative for sarcomeric protein mutations (HCMsmn). The rate constant of tension generation following maximal Ca2+ activation (kACT) and the rate constant of isometric relaxation (slow kREL) are markedly faster in K280N myofibrils than in all control groups. Simultaneous measurements of maximal isometric ATPase activity and Ca2+-activated tension in demembranated muscle strips also demonstrate that the energy cost of tension generation is higher in the K280N than in all controls. Replacement of mutant protein by exchange with wild-type troponin in the K280N preparations reduces kACT, slow kREL, and tension cost close to control values. In donor myofibrils and HCMsmn demembranated strips, replacement of endogenous troponin with troponin containing the K280N mutant increases kACT, slow kREL, and tension cost. The K280N TNNT2 mutation directly alters the apparent cross-bridge kinetics and impairs sarcomere energetics. This result supports the hypothesis that inefficient ATP utilization by myofilaments plays a central role in the pathogenesis of the disease.
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Affiliation(s)
- Nicoletta Piroddi
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy
| | - E Rosalie Witjas-Paalberends
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Claudia Ferrara
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy
| | - Cecilia Ferrantini
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy.,LENS, Sesto Fiorentino (Firenze), Florence, Italy
| | - Giulia Vitale
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy
| | - Beatrice Scellini
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy
| | - Paul J M Wijnker
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Vasco Sequiera
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands
| | - Dennis Dooijes
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands.,Clinical Genetics, University Medical Center, Utrecht, Netherlands
| | - Cristobal Dos Remedios
- Department of Anatomy and Histology, Bosch Institute, The University of Sydney, Sydney, Australia
| | - Saskia Schlossarek
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Germany
| | - Man Ching Leung
- National Heart and Lung Institute, Imperial College, London, England, UK
| | - Andrew Messer
- National Heart and Lung Institute, Imperial College, London, England, UK
| | - Douglas G Ward
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | | | - Chiara Tesi
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy
| | - Lucie Carrier
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Centre for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Germany
| | | | - Steven B Marston
- National Heart and Lung Institute, Imperial College, London, England, UK
| | - Jolanda van der Velden
- Amsterdam UMC, Vrije Universiteit Amsterdam, Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands.,Clinical Genetics, University Medical Center, Utrecht, Netherlands.,ICIN-Netherlands, Heart Institute, Utrecht, Netherlands
| | - Corrado Poggesi
- Dipartimento di Medicina Sperimentale e Clinica, Università di Firenze, Florence, Italy .,LENS, Sesto Fiorentino (Firenze), Florence, Italy
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10
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Li D, Sun Y, Zhuang Q, Song Y, Wu B, Jia Z, Pan H, Zhou H, Hu S, Zhang B, Qiu Y, Dai Y, Chen S, Xu X, Zhu X, Lin A, Huang W, Liu Z, Yan Q. Mitochondrial dysfunction caused by m.2336T>C mutation with hypertrophic cardiomyopathy in cybrid cell lines. Mitochondrion 2018; 46:313-320. [PMID: 30196098 DOI: 10.1016/j.mito.2018.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/09/2018] [Accepted: 08/28/2018] [Indexed: 10/28/2022]
Abstract
Hypertrophic cardiomyopathy (HCM), affecting approximately 1 in 500 in the general population, is the most prominent cause of sudden heart disease-related mortality in the young. Mitochondrial DNA (mtDNA) mutations are among the primary causes of HCM. We previously identified a novel m.2336T>C homoplasmic mutation in the mitochondrial 16S rRNA gene (MT-RNR2) in a Chinese maternally inherited HCM family. However, the molecular mechanisms by which m.2336T>C mutation contributes to HCM remain elusive. Here we generated transferring mitochondria cell lines (cybrids) with a constant nuclear background by transferring mitochondria from immortalized lymphoblastoid cell lines carrying the HCM-associated m.2336T>C mutation into human mtDNA-less (ρ°) cells. Functional assays showed a decreased stability for 16S rRNA and the steady-state levels of its binding proteins in the mutant cybrids. This mutation impaired the mitochondrial translation capacity and resulted in many mitochondrial dysfunctions, including elevation of ROS generation, reduction of ATP production and impairment of mitochondrial membrane potential. Moreover, the mutant cybrids had poor physiological status and decreased survival ability. These results confirm that the m.2336T>C mutation leads to mitochondrial dysfunction and strongly suggest that this mutation may play a role in the pathogenesis of HCM.
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Affiliation(s)
- Dan Li
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China; Department of Urology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Yaping Sun
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qianqian Zhuang
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yanrui Song
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Bifeng Wu
- The First Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Zexiao Jia
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Huaye Pan
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Hui Zhou
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shuangyi Hu
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Bingtao Zhang
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yue Qiu
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yu Dai
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Siyuan Chen
- Stomatology Hospital, School of Medicine Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Xuejun Xu
- Stomatology Hospital, School of Medicine Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Xufen Zhu
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Aifu Lin
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Wendong Huang
- Departmentof Diabetes Complications and Metabolism, The Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Zhong Liu
- The First Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, Zhejiang 310003, China.
| | - Qingfeng Yan
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310058, China; The First Affiliated Hospital, School of Medicine Zhejiang University, Hangzhou, Zhejiang 310003, China; Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310058, China; Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou, Zhejiang 310058, China.
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11
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Mitochondrial Dysfunctions Contribute to Hypertrophic Cardiomyopathy in Patient iPSC-Derived Cardiomyocytes with MT-RNR2 Mutation. Stem Cell Reports 2018; 10:808-821. [PMID: 29456182 PMCID: PMC5918198 DOI: 10.1016/j.stemcr.2018.01.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 01/19/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death in young individuals. A potential role of mtDNA mutations in HCM is known. However, the underlying molecular mechanisms linking mtDNA mutations to HCM remain poorly understood due to lack of cell and animal models. Here, we generated induced pluripotent stem cell-derived cardiomyocytes (HCM-iPSC-CMs) from human patients in a maternally inherited HCM family who carry the m.2336T>C mutation in the mitochondrial 16S rRNA gene (MT-RNR2). The results showed that the m.2336T>C mutation resulted in mitochondrial dysfunctions and ultrastructure defects by decreasing the stability of 16S rRNA, which led to reduced levels of mitochondrial proteins. The ATP/ADP ratio and mitochondrial membrane potential were also reduced, thereby elevating the intracellular Ca2+ concentration, which was associated with numerous HCM-specific electrophysiological abnormalities. Our findings therefore provide an innovative insight into the pathogenesis of maternally inherited HCM. Generation of HCM-specific iPSC-CMs carrying the m.2336T>C mutation in MT-RNR2 m.2336T>C mutation results in mitochondrial dysfunctions Mitochondrial dysfunctions lead to increased [Ca2+]i and decreased ICaL Abnormal Ca2+ homeostasis is associated with HCM-specific abnormalities
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12
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Dierck F, Kuhn C, Rohr C, Hille S, Braune J, Sossalla S, Molt S, van der Ven PFM, Fürst DO, Frey N. The novel cardiac z-disc protein CEFIP regulates cardiomyocyte hypertrophy by modulating calcineurin signaling. J Biol Chem 2017; 292:15180-15191. [PMID: 28717008 DOI: 10.1074/jbc.m117.786764] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/04/2017] [Indexed: 11/06/2022] Open
Abstract
The z-disc is a structural component at the lateral borders of the sarcomere and is important for mechanical stability and contractility of both cardiac and skeletal muscles. Of note, the sarcomeric z-disc also represents a nodal point in cardiomyocyte function and signaling. Mutations of numerous z-disc proteins are associated with cardiomyopathies and muscle diseases. To identify additional z-disc proteins that might contribute to cardiac disease, we employed an in silico screen for cardiac-enriched cDNAs. This screen yielded a previously uncharacterized protein named cardiac-enriched FHL2-interacting protein (CEFIP), which exhibited a heart- and skeletal muscle-specific expression profile. Importantly, CEFIP was located at the z-disc and was up-regulated in several models of cardiomyopathy. We also found that CEFIP overexpression induced the fetal gene program and cardiomyocyte hypertrophy. Yeast two-hybrid screens revealed that CEFIP interacts with the calcineurin-binding protein four and a half LIM domains 2 (FHL2). Because FHL2 binds calcineurin, a phosphatase controlling hypertrophic signaling, we examined the effects of CEFIP on the calcineurin/nuclear factor of activated T-cell (NFAT) pathway. These experiments revealed that CEFIP overexpression further enhances calcineurin-dependent hypertrophic signal transduction, and its knockdown repressed hypertrophy and calcineurin/NFAT activity. In summary, we report on a previously uncharacterized protein CEFIP that modulates calcineurin/NFAT signaling in cardiomyocytes, a finding with possible implications for the pathogenesis of cardiomyopathy.
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Affiliation(s)
- Franziska Dierck
- From the Department of Internal Medicine III, University Medical Center of Schleswig-Holstein, 24105 Kiel.,the DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105 Kiel
| | - Christian Kuhn
- From the Department of Internal Medicine III, University Medical Center of Schleswig-Holstein, 24105 Kiel.,the DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105 Kiel
| | - Claudia Rohr
- the Department of Internal Medicine III, University of Heidelberg, 69120 Heidelberg, and
| | - Susanne Hille
- From the Department of Internal Medicine III, University Medical Center of Schleswig-Holstein, 24105 Kiel.,the DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105 Kiel
| | - Julia Braune
- the Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Samuel Sossalla
- From the Department of Internal Medicine III, University Medical Center of Schleswig-Holstein, 24105 Kiel.,the DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105 Kiel
| | - Sibylle Molt
- the Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Peter F M van der Ven
- the Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Dieter O Fürst
- the Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Norbert Frey
- From the Department of Internal Medicine III, University Medical Center of Schleswig-Holstein, 24105 Kiel, .,the DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, 24105 Kiel
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13
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Pasqualini FS, Nesmith AP, Horton RE, Sheehy SP, Parker KK. Mechanotransduction and Metabolism in Cardiomyocyte Microdomains. BIOMED RESEARCH INTERNATIONAL 2016; 2016:4081638. [PMID: 28044126 PMCID: PMC5164897 DOI: 10.1155/2016/4081638] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 01/11/2023]
Abstract
Efficient contractions of the left ventricle are ensured by the continuous transfer of adenosine triphosphate (ATP) from energy production sites, the mitochondria, to energy utilization sites, such as ionic pumps and the force-generating sarcomeres. To minimize the impact of intracellular ATP trafficking, sarcomeres and mitochondria are closely packed together and in proximity with other ultrastructures involved in excitation-contraction coupling, such as t-tubules and sarcoplasmic reticulum junctions. This complex microdomain has been referred to as the intracellular energetic unit. Here, we review the literature in support of the notion that cardiac homeostasis and disease are emergent properties of the hierarchical organization of these units. Specifically, we will focus on pathological alterations of this microdomain that result in cardiac diseases through energy imbalance and posttranslational modifications of the cytoskeletal proteins involved in mechanosensing and transduction.
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Affiliation(s)
- Francesco S. Pasqualini
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences, Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
- Institute for Regenerative Medicine (IREM), Wyss Translational Center, University and ETH Zurich, Zurich, Switzerland
| | - Alexander P. Nesmith
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences, Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Renita E. Horton
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences, Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
- James Worth Bagley College of Engineering and College of Agriculture and Life Sciences, Mississippi State University, Starkville, MS, USA
| | - Sean P. Sheehy
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences, Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
| | - Kevin Kit Parker
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, School of Engineering and Applied Sciences, Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA
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14
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Myoscape controls cardiac calcium cycling and contractility via regulation of L-type calcium channel surface expression. Nat Commun 2016; 7:11317. [PMID: 27122098 DOI: 10.1315/11317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 03/13/2016] [Indexed: 01/29/2023] Open
Abstract
Calcium signalling plays a critical role in the pathogenesis of heart failure. Here we describe a cardiac protein named Myoscape/FAM40B/STRIP2, which directly interacts with the L-type calcium channel. Knockdown of Myoscape in cardiomyocytes decreases calcium transients associated with smaller Ca(2+) amplitudes and a lower diastolic Ca(2+) content. Likewise, L-type calcium channel currents are significantly diminished on Myoscape ablation, and downregulation of Myoscape significantly reduces contractility of cardiomyocytes. Conversely, overexpression of Myoscape increases global Ca(2+) transients and enhances L-type Ca(2+) channel currents, and is sufficient to restore decreased currents in failing cardiomyocytes. In vivo, both Myoscape-depleted morphant zebrafish and Myoscape knockout (KO) mice display impairment of cardiac function progressing to advanced heart failure. Mechanistically, Myoscape-deficient mice show reduced L-type Ca(2+)currents, cell capacity and calcium current densities as a result of diminished LTCC surface expression. Finally, Myoscape expression is reduced in hearts from patients suffering of terminal heart failure, implying a role in human disease.
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15
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Myoscape controls cardiac calcium cycling and contractility via regulation of L-type calcium channel surface expression. Nat Commun 2016. [PMID: 27122098 PMCID: PMC5438100 DOI: 10.1038/ncomms11317] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Calcium signalling plays a critical role in the pathogenesis of heart failure. Here we describe a cardiac protein named Myoscape/FAM40B/STRIP2, which directly interacts with the L-type calcium channel. Knockdown of Myoscape in cardiomyocytes decreases calcium transients associated with smaller Ca2+ amplitudes and a lower diastolic Ca2+ content. Likewise, L-type calcium channel currents are significantly diminished on Myoscape ablation, and downregulation of Myoscape significantly reduces contractility of cardiomyocytes. Conversely, overexpression of Myoscape increases global Ca2+ transients and enhances L-type Ca2+ channel currents, and is sufficient to restore decreased currents in failing cardiomyocytes. In vivo, both Myoscape-depleted morphant zebrafish and Myoscape knockout (KO) mice display impairment of cardiac function progressing to advanced heart failure. Mechanistically, Myoscape-deficient mice show reduced L-type Ca2+currents, cell capacity and calcium current densities as a result of diminished LTCC surface expression. Finally, Myoscape expression is reduced in hearts from patients suffering of terminal heart failure, implying a role in human disease. Heart failure is a major public health issue but due to our poor disease understanding the current therapies are symptomatic. Here the authors identify Myoscape as a novel cardiac protein regulating membrane localization of the L-type calcium channel and heart's contractile force, thus promising new therapeutic avenues for heart failure.
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16
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Gilda JE, Lai X, Witzmann FA, Gomes AV. Delineation of Molecular Pathways Involved in Cardiomyopathies Caused by Troponin T Mutations. Mol Cell Proteomics 2016; 15:1962-81. [PMID: 27022107 DOI: 10.1074/mcp.m115.057380] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Indexed: 11/06/2022] Open
Abstract
Familial hypertrophic cardiomyopathy (FHC) is associated with mild to severe cardiac problems and is the leading cause of sudden death in young people and athletes. Although the genetic basis for FHC is well-established, the molecular mechanisms that ultimately lead to cardiac dysfunction are not well understood. To obtain important insights into the molecular mechanism(s) involved in FHC, hearts from two FHC troponin T models (Ile79Asn [I79N] and Arg278Cys [R278C]) were investigated using label-free proteomics and metabolomics. Mutations in troponin T are the third most common cause of FHC, and the I79N mutation is associated with a high risk of sudden cardiac death. Most FHC-causing mutations, including I79N, increase the Ca(2+) sensitivity of the myofilament; however, the R278C mutation does not alter Ca(2+) sensitivity and is associated with a better prognosis than most FHC mutations. Out of more than 1200 identified proteins, 53 and 76 proteins were differentially expressed in I79N and R278C hearts, respectively, when compared with wild-type hearts. Interestingly, more than 400 proteins were differentially expressed when the I79N and R278C hearts were directly compared. The three major pathways affected in I79N hearts relative to R278C and wild-type hearts were the ubiquitin-proteasome system, antioxidant systems, and energy production pathways. Further investigation of the proteasome system using Western blotting and activity assays showed that proteasome dysfunction occurs in I79N hearts. Metabolomic results corroborate the proteomic data and suggest the glycolytic, citric acid, and electron transport chain pathways are important pathways that are altered in I79N hearts relative to R278C or wild-type hearts. Our findings suggest that impaired energy production and protein degradation dysfunction are important mechanisms in FHCs associated with poor prognosis and that cardiac hypertrophy is not likely needed for a switch from fatty acid to glucose metabolism.
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Affiliation(s)
| | - Xianyin Lai
- ¶Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Frank A Witzmann
- ¶Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Aldrin V Gomes
- From the ‡Department of Neurobiology, Physiology, and Behavior, §Department of Physiology and Membrane Biology, University of California, Davis, California 95616;
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17
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Bakermans AJ, Abdurrachim D, Moonen RPM, Motaal AG, Prompers JJ, Strijkers GJ, Vandoorne K, Nicolay K. Small animal cardiovascular MR imaging and spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 88-89:1-47. [PMID: 26282195 DOI: 10.1016/j.pnmrs.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
The use of MR imaging and spectroscopy for studying cardiovascular disease processes in small animals has increased tremendously over the past decade. This is the result of the remarkable advances in MR technologies and the increased availability of genetically modified mice. MR techniques provide a window on the entire timeline of cardiovascular disease development, ranging from subtle early changes in myocardial metabolism that often mark disease onset to severe myocardial dysfunction associated with end-stage heart failure. MR imaging and spectroscopy techniques play an important role in basic cardiovascular research and in cardiovascular disease diagnosis and therapy follow-up. This is due to the broad range of functional, structural and metabolic parameters that can be quantified by MR under in vivo conditions non-invasively. This review describes the spectrum of MR techniques that are employed in small animal cardiovascular disease research and how the technological challenges resulting from the small dimensions of heart and blood vessels as well as high heart and respiratory rates, particularly in mice, are tackled.
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Affiliation(s)
- Adrianus J Bakermans
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Desiree Abdurrachim
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rik P M Moonen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Abdallah G Motaal
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Katrien Vandoorne
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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18
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Valentin JP, Guth B, Hamlin RL, Lainée P, Sarazan D, Skinner M. Functional Cardiac Safety Evaluation of Novel Therapeutics. METHODS AND PRINCIPLES IN MEDICINAL CHEMISTRY 2015. [DOI: 10.1002/9783527673643.ch10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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19
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Månsson A. Hypothesis and theory: mechanical instabilities and non-uniformities in hereditary sarcomere myopathies. Front Physiol 2014; 5:350. [PMID: 25309450 PMCID: PMC4163974 DOI: 10.3389/fphys.2014.00350] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/26/2014] [Indexed: 12/23/2022] Open
Abstract
Familial hypertrophic cardiomyopathy (HCM), due to point mutations in genes for sarcomere proteins such as myosin, occurs in 1/500 people and is the most common cause of sudden death in young individuals. Similar mutations in skeletal muscle, e.g., in the MYH7 gene for slow myosin found in both the cardiac ventricle and slow skeletal muscle, may also cause severe disease but the severity and the morphological changes are often different. In HCM, the modified protein function leads, over years to decades, to secondary remodeling with substantial morphological changes, such as hypertrophy, myofibrillar disarray, and extensive fibrosis associated with severe functional deterioration. Despite intense studies, it is unclear how the moderate mutation-induced changes in protein function cause the long-term effects. In hypertrophy of the heart due to pressure overload (e.g., hypertension), mechanical stress in the myocyte is believed to be major initiating stimulus for activation of relevant cell signaling cascades. Here it is considered how expression of mutated proteins, such as myosin or regulatory proteins, could have similar consequences through one or both of the following mechanisms: (1) contractile instabilities within each sarcomere (with more than one stable velocity for a given load), (2) different tension generating capacities of cells in series. These mechanisms would have the potential to cause increased tension and/or stretch of certain cells during parts of the cardiac cycle. Modeling studies are used to illustrate these ideas and experimental tests are proposed. The applicability of similar ideas to skeletal muscle is also postulated, and differences between heart and skeletal muscle are discussed.
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Affiliation(s)
- Alf Månsson
- Department of Chemistry and Biomedical Sciences, Linnaeus University Kalmar, Sweden
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Witjas-Paalberends ER, Güçlü A, Germans T, Knaapen P, Harms HJ, Vermeer AMC, Christiaans I, Wilde AAM, Dos Remedios C, Lammertsma AA, van Rossum AC, Stienen GJM, van Slegtenhorst M, Schinkel AF, Michels M, Ho CY, Poggesi C, van der Velden J. Gene-specific increase in the energetic cost of contraction in hypertrophic cardiomyopathy caused by thick filament mutations. Cardiovasc Res 2014; 103:248-57. [PMID: 24835277 DOI: 10.1093/cvr/cvu127] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Disease mechanisms regarding hypertrophic cardiomyopathy (HCM) are largely unknown and disease onset varies. Sarcomere mutations might induce energy depletion for which until now there is no direct evidence at sarcomere level in human HCM. This study investigated if mutations in genes encoding myosin-binding protein C (MYBPC3) and myosin heavy chain (MYH7) underlie changes in the energetic cost of contraction in the development of human HCM disease. METHODS AND RESULTS Energetic cost of contraction was studied in vitro by measurements of force development and ATPase activity in cardiac muscle strips from 26 manifest HCM patients (11 MYBPC3mut, 9 MYH7mut, and 6 sarcomere mutation-negative, HCMsmn). In addition, in vivo, the ratio between external work (EW) and myocardial oxygen consumption (MVO2) to obtain myocardial external efficiency (MEE) was determined in 28 pre-hypertrophic mutation carriers (14 MYBPC3mut and 14 MYH7mut) and 14 healthy controls using [(11)C]-acetate positron emission tomography and cardiovascular magnetic resonance imaging. Tension cost (TC), i.e. ATPase activity during force development, was higher in MYBPC3mut and MYH7mut compared with HCMsmn at saturating [Ca(2+)]. TC was also significantly higher in MYH7mut at submaximal, more physiological [Ca(2+)]. EW was significantly lower in both mutation carrier groups, while MVO2 did not differ. MEE was significantly lower in both mutation carrier groups compared with controls, showing the lowest efficiency in MYH7 mutation carriers. CONCLUSION We provide direct evidence that sarcomere mutations perturb the energetic cost of cardiac contraction. Gene-specific severity of cardiac abnormalities may underlie differences in disease onset and suggests that early initiation of metabolic treatment may be beneficial, in particular, in MYH7 mutation carriers.
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Affiliation(s)
- E Rosalie Witjas-Paalberends
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Ahmet Güçlü
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands ICIN Netherlands Heart Institute, Utrecht, The Netherlands
| | - Tjeerd Germans
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Paul Knaapen
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Hendrik J Harms
- Department of Radiology and Nuclear Medicine, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Alexa M C Vermeer
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Imke Christiaans
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Arthur A M Wilde
- Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Cris Dos Remedios
- Institute for Biomedical Research, Muscle Research Unit, University of Sydney, Sydney, Australia
| | - Adriaan A Lammertsma
- Department of Radiology and Nuclear Medicine, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands
| | - Albert C van Rossum
- Department of Cardiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Ger J M Stienen
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands Department of Physics and Astronomy, VU University, Amsterdam, The Netherlands
| | | | - Arend F Schinkel
- Thorax Center, Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Michelle Michels
- Thorax Center, Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Carolyn Y Ho
- Brigham and Women's Hospital, Cardiology, Boston, MA, USA
| | - Corrado Poggesi
- Department of Physiology, University of Florence, Florence, Italy
| | - Jolanda van der Velden
- Department of Physiology, Institute for Cardiovascular Research (ICaR-VU), VU University Medical Center, Amsterdam, The Netherlands ICIN Netherlands Heart Institute, Utrecht, The Netherlands
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21
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Poggesi C, Ho CY. Muscle dysfunction in hypertrophic cardiomyopathy: what is needed to move to translation? J Muscle Res Cell Motil 2014; 35:37-45. [PMID: 24493262 DOI: 10.1007/s10974-014-9374-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 01/02/2014] [Indexed: 02/04/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomere genes. As such, HCM provides remarkable opportunities to study how changes to the heart's molecular motor apparatus may influence cardiac structure and function. Although the genetic basis of HCM is well-described, there is much more limited understanding of the precise consequences of sarcomere mutations--how they remodel the heart, and how these changes lead to the dramatic clinical consequences associated with HCM. More precise characterization of the mechanisms leading from sarcomere mutation to altered cardiac muscle function is critical to gain insight into fundamental disease biology and phenotypic evolution. Such knowledge will help foster development of novel treatment strategies aimed at correcting and preventing disease development in HCM.
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Affiliation(s)
- Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of Florence, Viale Morgagni 63, 50134, Florence, Italy,
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22
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Zhou LY, Liu JP, Wang K, Gao J, Ding SL, Jiao JQ, Li PF. Mitochondrial function in cardiac hypertrophy. Int J Cardiol 2012; 167:1118-25. [PMID: 23044430 DOI: 10.1016/j.ijcard.2012.09.082] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 08/24/2012] [Accepted: 09/15/2012] [Indexed: 10/27/2022]
Abstract
Cardiac hypertrophic program is a chronic, complex process, and occurs in response to long-term increases of hemodynamic load related to a variety of pathophysiological conditions. Mitochondria, known as "the cellular power plants", occupy about one-third of cardiomyocyte volume and supply roughly 90% of the adenosine triphosphate (ATP). Impairment of energy metabolism has been regarded as one of the main pathogenesis of cardiac hypertrophy. Thus, we summarize here the molecular events of mitochondrial adaptations, including the mitochondrial genesis, ATP generation, ROS signaling and Ca(2+) homeostasis in cardiac hypertrophy, expecting that this effort will shed new light on understanding the maladaptive cardiac remodeling.
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Affiliation(s)
- Lu-Yu Zhou
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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23
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Rivard K, Grandy SA, Douillette A, Paradis P, Nemer M, Allen BG, Fiset C. Overexpression of type 1 angiotensin II receptors impairs excitation-contraction coupling in the mouse heart. Am J Physiol Heart Circ Physiol 2011; 301:H2018-27. [DOI: 10.1152/ajpheart.01092.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transgenic mice that overexpress human type 1 angiotensin II receptor (AT1R) in the heart develop cardiac hypertrophy. Previously, we have shown that in 6-mo AT1R mice, which exhibit significant cardiac remodeling, fractional shortening is decreased. However, it is not clear whether altered contractility is attributable to AT1R overexpression or is secondary to cardiac hypertrophy/remodeling. Thus the present study characterized the effects of AT1R overexpression on ventricular L-type Ca2+ currents ( ICaL), cell shortening, and Ca2+ handling in 50-day and 6-mo-old male AT1R mice. Echocardiography showed there was no evidence of cardiac hypertrophy in 50-day AT1R mice but that fractional shortening was decreased. Cellular experiments showed that cell shortening, ICaL, and Cav1.2 mRNA expression were significantly reduced in 50-day and 6-mo-old AT1R mice compared with controls. In addition, Ca2+ transients and caffeine-induced Ca2+ transients were reduced whereas the time to 90% Ca2+ transient decay was prolonged in both age groups of AT1R mice. Western blot analysis revealed that sarcoplasmic reticulum Ca2+-ATPase and Na+/Ca2+ exchanger protein expression was significantly decreased in 50-day and 6-mo AT1R mice. Overall, the data show that cardiac contractility and the mechanisms that underlie excitation-contraction coupling are altered in AT1R mice. Furthermore, since the alterations in contractility occur before the development of cardiac hypertrophy, it is likely that these changes are attributable to the increased activity of the renin-angiotensin system brought about by AT1R overexpression. Thus it is possible that AT1R blockade may help maintain cardiac contractility in individuals with heart disease.
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Affiliation(s)
- Katy Rivard
- Research Centre, Montreal Heart Institute, Montreal,
- Faculty of Pharmacy, Université de Montréal, Montreal,
| | - Scott A. Grandy
- Research Centre, Montreal Heart Institute, Montreal,
- Faculty of Pharmacy, Université de Montréal, Montreal,
| | - Annie Douillette
- Research Centre, Montreal Heart Institute, Montreal,
- Faculty of Pharmacy, Université de Montréal, Montreal,
| | | | | | | | - Céline Fiset
- Research Centre, Montreal Heart Institute, Montreal,
- Faculty of Pharmacy, Université de Montréal, Montreal,
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24
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Abstract
Hypertrophic cardiomyopathy (HCM) is the most-common monogenically inherited form of heart disease, characterized by thickening of the left ventricular wall, contractile dysfunction, and potentially fatal arrhythmias. HCM is also the most-common cause of sudden cardiac death in individuals younger than 35 years of age. Much progress has been made in the elucidation of the genetic basis of HCM, resulting in the identification of more than 900 individual mutations in over 20 genes. Interestingly, most of these genes encode sarcomeric proteins, such as myosin-7 (also known as cardiac muscle β-myosin heavy chain; MYH7), cardiac myosin-binding protein C (MYBPC3), and cardiac muscle troponin T (TNNT2). However, the molecular events that ultimately lead to the clinical phenotype of HCM are still unclear. We discuss several potential pathways, which include altered calcium cycling and sarcomeric calcium sensitivity, increased fibrosis, disturbed biomechanical stress sensing, and impaired cardiac energy homeostasis. An improved understanding of the pathological mechanisms involved will result in greater specificity and success of therapies for patients with HCM.
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Affiliation(s)
- Norbert Frey
- Department of Cardiology and Angiology, University of Kiel, Schittenhelmstrasse 12, 24105 Kiel, Germany
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25
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Ashrafian H, McKenna WJ, Watkins H. Disease pathways and novel therapeutic targets in hypertrophic cardiomyopathy. Circ Res 2011; 109:86-96. [PMID: 21700950 DOI: 10.1161/circresaha.111.242974] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
As described in earlier reviews in this series on the molecular basis of hypertrophic cardiomyopathy (HCM), HCM is one of the archetypal monogenic cardiovascular disorders to be understood at the molecular level. Twenty years after the discovery of the first HCM disease gene, genetic studies still confirm that HCM is principally a disease of the sarcomere. At the biophysical level, myofilament mutations generally enhance Ca(2+) sensitivity, maximal force production, and ATPase activity. These defects ultimately appear to converge on energy deficiency and altered Ca(2+) handling as major common paths leading to the anatomic (hypertrophy, myofiber disarray, and fibrosis) and functional features (pathological signaling and diastolic dysfunction) characteristic of HCM. In this review, we provide an account of the consequences of HCM mutations and describe how specifically targeting these molecular features has already yielded early promise for novel therapies for HCM. Although substantial efforts are still required to understand the molecular link between HCM mutations and their clinical consequences, HCM endures as an exemplar of how novel insights derived from molecular characterization of Mendelian disorders can inform the understanding of biological processes and translate into rational therapies.
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Affiliation(s)
- Houman Ashrafian
- Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom
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26
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[Advances in the molecular pathogenesis of hypertrophic cardiomyopathy]. YI CHUAN = HEREDITAS 2011; 33:549-57. [PMID: 21684859 DOI: 10.3724/sp.j.1005.2011.00549] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hypertrophic Cardiomyopathy (HCM) is a primary cardiac disorder characterized by asymmetric thickening of the septum and left ventricular wall. HCM affects 1 in 500 individuals in the general population, and it is the most common cause of sudden death in the young and athletes. The clinic phenotype of HCM is highly variable with respect to age at onset, degree of symptoms, and risk of sudden death. HCM is usually inherited as a Mendelian autosomal dominant trait. To date, over 900 mutations have been reported in HCM, which were mainly located in 13 genes encoding cardiac sarcomere protein, e.g., MYH7, MYBPC3, and TnT. In addition, more and more mitochondrial DNA mutations were reported to be associated with the pathogenesis of HCM. Based on the description of the clinical phenotype and morphological characteristics, this review focuses on the research in the molecular pathogenic mechanism of HCM and its recent advances.
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Abozguia K, Elliott P, McKenna W, Phan TT, Nallur-Shivu G, Ahmed I, Maher AR, Kaur K, Taylor J, Henning A, Ashrafian H, Watkins H, Frenneaux M. Metabolic modulator perhexiline corrects energy deficiency and improves exercise capacity in symptomatic hypertrophic cardiomyopathy. Circulation 2010; 122:1562-9. [PMID: 20921440 DOI: 10.1161/circulationaha.109.934059] [Citation(s) in RCA: 212] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy patients exhibit myocardial energetic impairment, but a causative role for this energy deficiency in the pathophysiology of hypertrophic cardiomyopathy remains unproven. We hypothesized that the metabolic modulator perhexiline would ameliorate myocardial energy deficiency and thereby improve diastolic function and exercise capacity. METHODS AND RESULTS Forty-six consecutive patients with symptomatic exercise limitation (peak Vo(2) <75% of predicted) caused by nonobstructive hypertrophic cardiomyopathy (mean age, 55±0.26 years) were randomized to perhexiline 100 mg (n=24) or placebo (n=22). Myocardial ratio of phosphocreatine to adenosine triphosphate, an established marker of cardiac energetic status, as measured by (31)P magnetic resonance spectroscopy, left ventricular diastolic filling (heart rate normalized time to peak filling) at rest and during exercise using radionuclide ventriculography, peak Vo(2), symptoms, quality of life, and serum metabolites were assessed at baseline and study end (4.6±1.8 months). Perhexiline improved myocardial ratios of phosphocreatine to adenosine triphosphate (from 1.27±0.02 to 1.73±0.02 versus 1.29±0.01 to 1.23±0.01; P=0.003) and normalized the abnormal prolongation of heart rate normalized time to peak filling between rest and exercise (0.11±0.008 to -0.01±0.005 versus 0.15±0.007 to 0.11±0.008 second; P=0.03). These changes were accompanied by an improvement in primary end point (peak Vo(2)) (22.2±0.2 to 24.3±0.2 versus 23.6±0.3 to 22.3±0.2 mL · kg(-1) · min(-1); P=0.003) and New York Heart Association class (P<0.001) (all P values ANCOVA, perhexiline versus placebo). CONCLUSIONS In symptomatic hypertrophic cardiomyopathy, perhexiline, a modulator of substrate metabolism, ameliorates cardiac energetic impairment, corrects diastolic dysfunction, and increases exercise capacity. This study supports the hypothesis that energy deficiency contributes to the pathophysiology and provides a rationale for further consideration of metabolic therapies in hypertrophic cardiomyopathy.
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Affiliation(s)
- Khalid Abozguia
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
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28
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Huke S, Knollmann BC. Increased myofilament Ca2+-sensitivity and arrhythmia susceptibility. J Mol Cell Cardiol 2010; 48:824-33. [PMID: 20097204 PMCID: PMC2854218 DOI: 10.1016/j.yjmcc.2010.01.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/12/2010] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
Abstract
Increased myofilament Ca(2+) sensitivity is a common attribute of many inherited and acquired cardiomyopathies that are associated with cardiac arrhythmias. Accumulating evidence supports the concept that increased myofilament Ca(2+) sensitivity is an independent risk factor for arrhythmias. This review describes and discusses potential underlying molecular and cellular mechanisms how myofilament Ca(2+) sensitivity affects cardiac excitation and leads to the generation of arrhythmias. Emphasized are downstream effects of increased myofilament Ca(2+) sensitivity: altered Ca(2+) buffering/handling, impaired energy metabolism and increased mechanical stretch, and how they may contribute to arrhythmogenesis.
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Affiliation(s)
- Sabine Huke
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN 37232-0575, USA
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29
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Luedde M, Ehlermann P, Weichenhan D, Will R, Zeller R, Rupp S, Müller A, Steen H, Ivandic BT, Ulmer HE, Kern M, Katus HA, Frey N. Severe familial left ventricular non-compaction cardiomyopathy due to a novel troponin T (TNNT2) mutation. Cardiovasc Res 2010; 86:452-60. [DOI: 10.1093/cvr/cvq009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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30
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Shephard R, Semsarian C. Role of animal models in HCM research. J Cardiovasc Transl Res 2009; 2:471-82. [PMID: 20560005 DOI: 10.1007/s12265-009-9120-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 07/17/2009] [Indexed: 10/25/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is a complex cardiovascular genetic disorder characterized by marked clinical and genetic heterogeneity. Major advances have been made in the clinical characterization of patients with HCM and in identifying causative gene mutations. However, many questions remain regarding the underlying disease mechanisms. Furthermore, in a disease where no pharmacological treatments currently exists which can either prevent or cause regression of disease, processes to identify novel therapies are the crucial next steps. Animal models of HCM have already proved to be universally useful in confirming gene causation and dissecting out key molecular pathways involved in the development of HCM and its sequelae, including heart failure and sudden death. These findings have led to studies in animal models investigating novel therapeutic approaches in HCM, specifically targeting the development and progression of cardiac hypertrophy, fibrosis, and heart failure. This review will provide a brief summary of some of the key animal models of HCM and how these models have been utilized to understand disease mechanisms and to investigate new potential therapies. Ongoing studies using animal models of HCM will lead to a greater understanding of disease pathogenesis and will facilitate the translation of these findings to improved clinical outcomes in HCM patients.
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Affiliation(s)
- Rhian Shephard
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Locked Bag 6, Newtown, Sydney, NSW, 2042, Australia
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