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Haffner V, Nourian Z, Boerman EM, Lambert MD, Hanft LM, Krenz M, Baines CP, Duan D, McDonald KS, Domeier TL. Calcium handling dysfunction and cardiac damage following acute ventricular preload challenge in the dystrophin-deficient mouse heart. Am J Physiol Heart Circ Physiol 2023; 325:H1168-H1177. [PMID: 37737731 PMCID: PMC10907071 DOI: 10.1152/ajpheart.00265.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/23/2023]
Abstract
Duchenne muscular dystrophy (DMD) is the most common muscular dystrophy and is caused by mutations in the dystrophin gene. Dystrophin deficiency is associated with structural and functional changes of the muscle cell sarcolemma and/or stretch-induced ion channel activation. In this investigation, we use mice with transgenic cardiomyocyte-specific expression of the GCaMP6f Ca2+ indicator to test the hypothesis that dystrophin deficiency leads to cardiomyocyte Ca2+ handling abnormalities following preload challenge. α-MHC-MerCreMer-GCaMP6f transgenic mice were developed on both a wild-type (WT) or dystrophic (Dmdmdx-4Cv) background. Isolated hearts of 3-7-mo male mice were perfused in unloaded Langendorff mode (0 mmHg) and working heart mode (preload = 20 mmHg). Following a 30-min preload challenge, hearts were perfused in unloaded Langendorff mode with 40 μM blebbistatin, and GCaMP6f was imaged using confocal fluorescence microscopy. Incidence of premature ventricular complexes (PVCs) was monitored before and following preload elevation at 20 mmHg. Hearts of both wild-type and dystrophic mice exhibited similar left ventricular contractile function. Following preload challenge, dystrophic hearts exhibited a reduction in GCaMP6f-positive cardiomyocytes and an increase in number of cardiomyocytes exhibiting Ca2+ waves/overload. Incidence of cardiac arrhythmias was low in both wild-type and dystrophic hearts during unloaded Langendorff mode. However, after preload elevation to 20-mmHg hearts of dystrophic mice exhibited an increased incidence of PVCs compared with hearts of wild-type mice. In conclusion, these data indicate susceptibility to preload-induced Ca2+ overload, ventricular damage, and ventricular dysfunction in male Dmdmdx-4Cv hearts. Our data support the hypothesis that cardiomyocyte Ca2+ overload underlies cardiac dysfunction in muscular dystrophy.NEW & NOTEWORTHY The mechanisms of cardiac disease progression in muscular dystrophy are complex and poorly understood. Using a transgenic mouse model with cardiomyocyte-specific expression of the GCaMP6f Ca2+ indicator, the present study provides further support for the Ca2+-overload hypothesis of disease progression and ventricular arrhythmogenesis in muscular dystrophy.
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Affiliation(s)
- Vivian Haffner
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Zahra Nourian
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Michelle D Lambert
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Laurin M Hanft
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Maike Krenz
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
- The Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States
| | - Christopher P Baines
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States
- The Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, Missouri, United States
- Department of Neurology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Kerry S McDonald
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
| | - Timothy L Domeier
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, Missouri, United States
- Department of Medicine, School of Medicine, University of Missouri, Columbia, Missouri, United States
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2
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Wilson AJ, Sands GB, LeGrice IJ, Young AA, Ennis DB. Myocardial mesostructure and mesofunction. Am J Physiol Heart Circ Physiol 2022; 323:H257-H275. [PMID: 35657613 PMCID: PMC9273275 DOI: 10.1152/ajpheart.00059.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 11/22/2022]
Abstract
The complex and highly organized structural arrangement of some five billion cardiomyocytes directs the coordinated electrical activity and mechanical contraction of the human heart. The characteristic transmural change in cardiomyocyte orientation underlies base-to-apex shortening, circumferential shortening, and left ventricular torsion during contraction. Individual cardiomyocytes shorten ∼15% and increase in diameter ∼8%. Remarkably, however, the left ventricular wall thickens by up to 30-40%. To accommodate this, the myocardium must undergo significant structural rearrangement during contraction. At the mesoscale, collections of cardiomyocytes are organized into sheetlets, and sheetlet shear is the fundamental mechanism of rearrangement that produces wall thickening. Herein, we review the histological and physiological studies of myocardial mesostructure that have established the sheetlet shear model of wall thickening. Recent developments in tissue clearing techniques allow for imaging of whole hearts at the cellular scale, whereas magnetic resonance imaging (MRI) and computed tomography (CT) can image the myocardium at the mesoscale (100 µm to 1 mm) to resolve cardiomyocyte orientation and organization. Through histology, cardiac diffusion tensor imaging (DTI), and other modalities, mesostructural sheetlets have been confirmed in both animal and human hearts. Recent in vivo cardiac DTI methods have measured reorientation of sheetlets during the cardiac cycle. We also examine the role of pathological cardiac remodeling on sheetlet organization and reorientation, and the impact this has on ventricular function and dysfunction. We also review the unresolved mesostructural questions and challenges that may direct future work in the field.
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Affiliation(s)
- Alexander J Wilson
- Department of Radiology, Stanford University, Stanford, California
- Stanford Cardiovascular Institute, Stanford University, Stanford, California
| | - Gregory B Sands
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Ian J LeGrice
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alistair A Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Daniel B Ennis
- Department of Radiology, Stanford University, Stanford, California
- Veterans Administration Palo Alto Health Care System, Palo Alto, California
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3
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Le B, Ferreira P, Merchant S, Zheng G, Sutherland MR, Dahl MJ, Albertine KH, Black MJ. Microarchitecture of the hearts in term and former-preterm lambs using diffusion tensor imaging. Anat Rec (Hoboken) 2020; 304:803-817. [PMID: 33015923 DOI: 10.1002/ar.24516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/31/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022]
Abstract
Diffusion tensor imaging (DTI) is an MRI technique that can be used to map cardiomyocyte tracts and estimate local cardiomyocyte and sheetlet orientation within the heart. DTI measures diffusion distances of water molecules within the myocardium, where water diffusion generally occurs more freely along the long axis of cardiomyocytes and within the extracellular matrix, but is restricted by cell membranes such that transverse diffusion is limited. DTI can be undertaken in fixed hearts and it allows the three-dimensional mapping of the cardiac microarchitecture, including cardiomyocyte organization, within the whole heart. The objective of this study was to use DTI to compare the cardiac microarchitecture and cardiomyocyte organization in archived fixed left ventricles of lambs that were born either preterm (n = 5) or at term (n = 7), at a postnatal timepoint equivalent to about 6 years of age in children. Although the findings support the feasibility of retrospective DTI scanning of fixed hearts, several hearts were excluded from DTI analysis because of poor scan quality, such as ghosting artifacts. The preliminary findings from viable DTI scans (n = 3/group) suggest that the extracellular compartment is altered and that there is an immature microstructural phenotype early in postnatal life in the LV of lambs born preterm. Our findings support a potential time-efficient imaging role for DTI in detecting abnormal changes in the microstructure of fixed hearts of former-preterm neonates, although further investigation into factors that affect scan quality is required.
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Affiliation(s)
- Bianca Le
- Department of Anatomy and Developmental Biology and Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | | | - Samer Merchant
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
| | - Gang Zheng
- Monash Biomedical Imaging, Monash University, Victoria, Australia
| | - Megan R Sutherland
- Department of Anatomy and Developmental Biology and Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | - Mar Janna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Mary Jane Black
- Department of Anatomy and Developmental Biology and Biomedicine Discovery Institute, Monash University, Victoria, Australia
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4
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Kim MJ, Bible KL, Regnier M, Adams ME, Froehner SC, Whitehead NP. Simvastatin provides long-term improvement of left ventricular function and prevents cardiac fibrosis in muscular dystrophy. Physiol Rep 2020; 7:e14018. [PMID: 30912308 PMCID: PMC6434171 DOI: 10.14814/phy2.14018] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/23/2019] [Accepted: 01/28/2019] [Indexed: 11/24/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), caused by absence of the protein dystrophin, is a common, degenerative muscle disease affecting 1:5000 males worldwide. With recent advances in respiratory care, cardiac dysfunction now accounts for 50% of mortality in DMD. Recently, we demonstrated that simvastatin substantially improved skeletal muscle health and function in mdx (DMD) mice. Given the known cardiovascular benefits ascribed to statins, the aim of this study was to evaluate the efficacy of simvastatin on cardiac function in mdx mice. Remarkably, in 12‐month old mdx mice, simvastatin reversed diastolic dysfunction to normal after short‐term treatment (8 weeks), as measured by echocardiography in animals anesthetized with isoflurane and administered dobutamine to maintain a physiological heart rate. This improvement in diastolic function was accompanied by increased phospholamban phosphorylation in simvastatin‐treated mice. Echocardiography measurements during long‐term treatment, from 6 months up to 18 months of age, showed that simvastatin significantly improved in vivo cardiac function compared to untreated mdx mice, and prevented fibrosis in these very old animals. Cardiac dysfunction in DMD is also characterized by decreased heart rate variability (HRV), which indicates autonomic function dysregulation. Therefore, we measured cardiac ECG and demonstrated that short‐term simvastatin treatment significantly increased heart rate variability (HRV) in 14‐month‐old conscious mdx mice, which was reversed by atropine. This finding suggests that enhanced parasympathetic function is likely responsible for the improved HRV mediated by simvastatin. Together, these findings indicate that simvastatin markedly improves cardiac health and function in dystrophic mice, and therefore may provide a novel approach for treating cardiomyopathy in DMD.
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Affiliation(s)
- Min J Kim
- Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Kenneth L Bible
- Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Marvin E Adams
- Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Department of Physiology & Biophysics, University of Washington, Seattle, Washington
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5
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O'Shea C, Holmes AP, Yu TY, Winter J, Wells SP, Correia J, Boukens BJ, De Groot JR, Chu GS, Li X, Ng GA, Kirchhof P, Fabritz L, Rajpoot K, Pavlovic D. ElectroMap: High-throughput open-source software for analysis and mapping of cardiac electrophysiology. Sci Rep 2019; 9:1389. [PMID: 30718782 PMCID: PMC6362081 DOI: 10.1038/s41598-018-38263-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/21/2018] [Indexed: 02/04/2023] Open
Abstract
The ability to record and analyse electrical behaviour across the heart using optical and electrode mapping has revolutionised cardiac research. However, wider uptake of these technologies is constrained by the lack of multi-functional and robustly characterised analysis and mapping software. We present ElectroMap, an adaptable, high-throughput, open-source software for processing, analysis and mapping of complex electrophysiology datasets from diverse experimental models and acquisition modalities. Key innovation is development of standalone module for quantification of conduction velocity, employing multiple methodologies, currently not widely available to researchers. ElectroMap has also been designed to support multiple methodologies for accurate calculation of activation, repolarisation, arrhythmia detection, calcium handling and beat-to-beat heterogeneity. ElectroMap implements automated signal segmentation, ensemble averaging and integrates optogenetic approaches. Here we employ ElectroMap for analysis, mapping and detection of pro-arrhythmic phenomena in silico, in cellulo, animal model and in vivo patient datasets. We anticipate that ElectroMap will accelerate innovative cardiac research and enhance the uptake, application and interpretation of mapping technologies leading to novel approaches for arrhythmia prevention.
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Affiliation(s)
- Christopher O'Shea
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- EPSRC Centre for Doctoral Training in Physical Sciences for Health, School of Chemistry, University of Birmingham, Birmingham, UK
- School of Computer Science, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Ting Y Yu
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - James Winter
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Simon P Wells
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Joao Correia
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, UK
| | - Bastiaan J Boukens
- Amsterdam UMC, University of Amsterdam, Department of Anatomy and Physiology, Amsterdam, The Netherlands
| | - Joris R De Groot
- Amsterdam UMC, University of Amsterdam, Heart Center, Department of Cardiology, Amsterdam, The Netherlands
| | - Gavin S Chu
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - Xin Li
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - G Andre Ng
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, UHB NHS Trust, Birmingham, UK
| | - Larissa Fabritz
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Department of Cardiology, UHB NHS Trust, Birmingham, UK
| | - Kashif Rajpoot
- School of Computer Science, University of Birmingham, Birmingham, UK.
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK.
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6
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Crossman DJ, Shen X, Jüllig M, Munro M, Hou Y, Middleditch M, Shrestha D, Li A, Lal S, Dos Remedios CG, Baddeley D, Ruygrok PN, Soeller C. Increased collagen within the transverse tubules in human heart failure. Cardiovasc Res 2018; 113:879-891. [PMID: 28444133 DOI: 10.1093/cvr/cvx055] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 03/20/2017] [Indexed: 12/22/2022] Open
Abstract
Aims In heart failure transverse-tubule (t-tubule) remodelling disrupts calcium release, and contraction. T-tubules in human failing hearts exhibit increased labelling by wheat germ agglutinin (WGA), a lectin that binds to the dystrophin-associated glycoprotein complex. We hypothesized changes in this complex may explain the increased WGA labelling and contribute to t-tubule remodelling in the failing human heart. In this study we sought to identify the molecules responsible for this increased WGA labelling. Methods and results Confocal and super-resolution fluorescence microscopy and proteomic analyses were used to quantify left ventricle samples from healthy donors and patients with idiopathic dilated cardiomyopathy (IDCM). Confocal microscopy demonstrated both WGA and dystrophin were located at t-tubules. Super-resolution microscopy revealed that WGA labelling of t-tubules is largely located within the lumen while dystrophin was restricted to near the sarcolemma. Western blots probed with WGA reveal a 5.7-fold increase in a 140 kDa band in IDCM. Mass spectrometry identified this band as type VI collagen (Col-VI) comprised of α1(VI), α2(VI), and α3(VI) chains. Pertinently, mutations in Col-VI cause muscular dystrophy. Western blotting identified a 2.4-fold increased expression and 3.2-fold increased WGA binding of Col-VI in IDCM. Confocal images showed that Col-VI is located in the t-tubules and that their diameter increased in the IDCM samples. Super-resolution imaging revealed Col-VI was restricted to the t-tubule lumen where increases were associated with displacement in the sarcolemma as identified from dystrophin labelling. Samples were also labelled for type I, III, and IV collagen. Both confocal and super-resolution imaging identified that these collagens were also present within t-tubule lumen. Conclusion Increased expression and labelling of collagen in IDCM samples indicates fibrosis may contribute to t-tubule remodelling in human heart failure.
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Affiliation(s)
- David J Crossman
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Xin Shen
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Mia Jüllig
- School of Biological Sciences, University of Auckland, 3a Symonds Street, Auckland 1010, New Zealand
| | - Michelle Munro
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Yufeng Hou
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Martin Middleditch
- School of Biological Sciences, University of Auckland, 3a Symonds Street, Auckland 1010, New Zealand
| | - Darshan Shrestha
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Amy Li
- Bosch Institute, University of Sydney, Fisher Road Sydney, NSW 2006, Australia
| | - Sean Lal
- Bosch Institute, University of Sydney, Fisher Road Sydney, NSW 2006, Australia
| | | | - David Baddeley
- Department of Cell Biology, Yale University, West Campus, 300 Heffernan Drive, Haven, CT 06515, USA
| | - Peter N Ruygrok
- Department of Cardiology, Auckland City Hospital, Auckland 1042, New Zealand
| | - Christian Soeller
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand.,Living Systems Institute and Biomedical Physics, University of Exeter, Stocker Road, Exeter EX4QL, UK
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7
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Stoeck CT, von Deuster C, Fleischmann T, Lipiski M, Cesarovic N, Kozerke S. Direct comparison of in vivo versus postmortem second‐order motion‐compensated cardiac diffusion tensor imaging. Magn Reson Med 2017; 79:2265-2276. [DOI: 10.1002/mrm.26871] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Christian T. Stoeck
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
| | - Constantin von Deuster
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
| | - Thea Fleischmann
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Miriam Lipiski
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Nikola Cesarovic
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
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8
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Nielles-Vallespin S, Khalique Z, Ferreira PF, de Silva R, Scott AD, Kilner P, McGill LA, Giannakidis A, Gatehouse PD, Ennis D, Aliotta E, Al-Khalil M, Kellman P, Mazilu D, Balaban RS, Firmin DN, Arai AE, Pennell DJ. Assessment of Myocardial Microstructural Dynamics by In Vivo Diffusion Tensor Cardiac Magnetic Resonance. J Am Coll Cardiol 2017; 69:661-676. [PMID: 28183509 PMCID: PMC8672367 DOI: 10.1016/j.jacc.2016.11.051] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/29/2016] [Accepted: 11/07/2016] [Indexed: 01/23/2023]
Abstract
BACKGROUND Cardiomyocytes are organized in microstructures termed sheetlets that reorientate during left ventricular thickening. Diffusion tensor cardiac magnetic resonance (DT-CMR) may enable noninvasive interrogation of in vivo cardiac microstructural dynamics. Dilated cardiomyopathy (DCM) is a condition of abnormal myocardium with unknown sheetlet function. OBJECTIVES This study sought to validate in vivo DT-CMR measures of cardiac microstructure against histology, characterize microstructural dynamics during left ventricular wall thickening, and apply the technique in hypertrophic cardiomyopathy (HCM) and DCM. METHODS In vivo DT-CMR was acquired throughout the cardiac cycle in healthy swine, followed by in situ and ex vivo DT-CMR, then validated against histology. In vivo DT-CMR was performed in 19 control subjects, 19 DCM, and 13 HCM patients. RESULTS In swine, a DT-CMR index of sheetlet reorientation (E2A) changed substantially (E2A mobility ~46°). E2A changes correlated with wall thickness changes (in vivo r2 = 0.75; in situ r2 = 0.89), were consistently observed under all experimental conditions, and accorded closely with histological analyses in both relaxed and contracted states. The potential contribution of cyclical strain effects to in vivo E2A was ~17%. In healthy human control subjects, E2A increased from diastole (18°) to systole (65°; p < 0.001; E2A mobility = 45°). HCM patients showed significantly greater E2A in diastole than control subjects did (48 ; p < 0.001) with impaired E2A mobility (23°; p < 0.001). In DCM, E2A was similar to control subjects in diastole, but systolic values were markedly lower (40° ; p < 0.001) with impaired E2A mobility (20°; p < 0.001). CONCLUSIONS Myocardial microstructure dynamics can be characterized by in vivo DT-CMR. Sheetlet function was abnormal in DCM with altered systolic conformation and reduced mobility, contrasting with HCM, which showed reduced mobility with altered diastolic conformation. These novel insights significantly improve understanding of contractile dysfunction at a level of noninvasive interrogation not previously available in humans. (J Am Coll Cardiol 2017;69:661–76) Published by Elsevier on behalf of the American College of Cardiology Foundation.
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Affiliation(s)
- Sonia Nielles-Vallespin
- National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom.
| | - Zohya Khalique
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Pedro F Ferreira
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Ranil de Silva
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Andrew D Scott
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Philip Kilner
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Laura-Ann McGill
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Archontis Giannakidis
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter D Gatehouse
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Daniel Ennis
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Eric Aliotta
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Majid Al-Khalil
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
| | - Dumitru Mazilu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
| | - Robert S Balaban
- National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
| | - David N Firmin
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
| | - Andrew E Arai
- National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
| | - Dudley J Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton and Harefield National Health Service Foundation Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield National Health Service Foundation Trust, and Imperial College London, London, United Kingdom
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9
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Crossman DJ, Jayasinghe ID, Soeller C. Transverse tubule remodelling: a cellular pathology driven by both sides of the plasmalemma? Biophys Rev 2017; 9:919-929. [PMID: 28695473 DOI: 10.1007/s12551-017-0273-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/06/2017] [Indexed: 01/10/2023] Open
Abstract
Transverse (t)-tubules are invaginations of the plasma membrane that form a complex network of ducts, 200-400 nm in diameter depending on the animal species, that penetrates deep within the cardiac myocyte, where they facilitate a fast and synchronous contraction across the entire cell volume. There is now a large body of evidence in animal models and humans demonstrating that pathological distortion of the t-tubule structure has a causative role in the loss of myocyte contractility that underpins many forms of heart failure. Investigations into the molecular mechanisms of pathological t-tubule remodelling to date have focused on proteins residing in the intracellular aspect of t-tubule membrane that form linkages between the membrane and myocyte cytoskeleton. In this review, we shed light on the mechanisms of t-tubule remodelling which are not limited to the intracellular side. Our recent data have demonstrated that collagen is an integral part of the t-tubule network and that it increases within the tubules in heart failure, suggesting that a fibrotic mechanism could drive cardiac junctional remodelling. We examine the evidence that the linkages between the extracellular matrix, t-tubule membrane and cellular cytoskeleton should be considered as a whole when investigating the mechanisms of t-tubule pathology in the failing heart.
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Affiliation(s)
- David J Crossman
- Department of Physiology, University of Auckland, Auckland, New Zealand.
| | | | - Christian Soeller
- Department of Physiology, University of Auckland, Auckland, New Zealand
- Biomedical Physics, University of Exeter, Exeter, UK
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10
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Wang Y, Zhang K, Duan D, Yao G. Heart structural remodeling in a mouse model of Duchenne cardiomyopathy revealed using optical polarization tractography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1271-1276. [PMID: 28663827 PMCID: PMC5480542 DOI: 10.1364/boe.8.001271] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/27/2017] [Accepted: 01/28/2017] [Indexed: 05/10/2023]
Abstract
We investigated the heart structural remodeling in the mdx4cv mouse model of Duchenne cardiomyopathy using optical polarization tractography. Whole heart tractography was obtained in freshly dissected hearts from six mdx4cv mice. Six hearts from C57BL/6J mice were also imaged as the normal control. The mdx4cv hearts were significantly larger than the control hearts and had significantly higher between-subject variations in myofiber organization. While both strains showed classic cross-helical fiber organization in the left ventricle, the rate of the myocardial fiber orientation change across the heart wall was significantly altered in the right ventricle of the mdx4cv heart.
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Affiliation(s)
- Y. Wang
- Department of Bioengineering, University of Missouri, Columbia, MO 65211, USA
| | - K. Zhang
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA
| | - D. Duan
- Department of Bioengineering, University of Missouri, Columbia, MO 65211, USA
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO 65211, USA
| | - G. Yao
- Department of Bioengineering, University of Missouri, Columbia, MO 65211, USA
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11
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Mekkaoui C, Reese TG, Jackowski MP, Bhat H, Sosnovik DE. Diffusion MRI in the heart. NMR IN BIOMEDICINE 2017; 30:e3426. [PMID: 26484848 PMCID: PMC5333463 DOI: 10.1002/nbm.3426] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 08/01/2015] [Accepted: 09/10/2015] [Indexed: 05/25/2023]
Abstract
Diffusion MRI provides unique information on the structure, organization, and integrity of the myocardium without the need for exogenous contrast agents. Diffusion MRI in the heart, however, has proven technically challenging because of the intrinsic non-rigid deformation during the cardiac cycle, displacement of the myocardium due to respiratory motion, signal inhomogeneity within the thorax, and short transverse relaxation times. Recently developed accelerated diffusion-weighted MR acquisition sequences combined with advanced post-processing techniques have improved the accuracy and efficiency of diffusion MRI in the myocardium. In this review, we describe the solutions and approaches that have been developed to enable diffusion MRI of the heart in vivo, including a dual-gated stimulated echo approach, a velocity- (M1 ) or an acceleration- (M2 ) compensated pulsed gradient spin echo approach, and the use of principal component analysis filtering. The structure of the myocardium and the application of these techniques in ischemic heart disease are also briefly reviewed. The advent of clinical MR systems with stronger gradients will likely facilitate the translation of cardiac diffusion MRI into clinical use. The addition of diffusion MRI to the well-established set of cardiovascular imaging techniques should lead to new and complementary approaches for the diagnosis and evaluation of patients with heart disease. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.
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Affiliation(s)
- Choukri Mekkaoui
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Timothy G Reese
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marcel P Jackowski
- Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil
| | | | - David E Sosnovik
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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12
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Abdullah OM, Seidel T, Dahl M, Gomez AD, Yiep G, Cortino J, Sachse FB, Albertine KH, Hsu EW. Diffusion tensor imaging and histology of developing hearts. NMR IN BIOMEDICINE 2016; 29:1338-1349. [PMID: 27485033 PMCID: PMC5160010 DOI: 10.1002/nbm.3576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 05/24/2016] [Accepted: 06/03/2016] [Indexed: 06/06/2023]
Abstract
Diffusion tensor imaging (DTI) has emerged as a promising method for noninvasive quantification of myocardial microstructure. However, the origin and behavior of DTI measurements during myocardial normal development and remodeling remain poorly understood. In this work, conventional and bicompartmental DTI in addition to three-dimensional histological correlation were performed in a sheep model of myocardial development from third trimester to postnatal 5 months of age. Comparing the earliest time points in the third trimester with the postnatal 5 month group, the scalar transverse diffusivities preferentially increased in both left ventricle (LV) and right ventricle (RV): secondary eigenvalues D2 increased by 54% (LV) and 36% (RV), whereas tertiary eigenvalues D3 increased by 85% (LV) and 67% (RV). The longitudinal diffusivity D1 changes were small, which led to a decrease in fractional anisotropy by 41% (LV) and 33% (RV) in 5 month versus fetal hearts. Histological analysis suggested that myocardial development is associated with hyperplasia in the early stages of the third trimester followed by myocyte growth in the later stages up to 5 months of age (increased average myocyte width by 198%, myocyte length by 128%, and decreased nucleus density by 70% between preterm and postnatal 5 month hearts.) In a few histological samples (N = 6), correlations were observed between DTI longitudinal diffusivity and myocyte length (r = 0.86, P < 0.05), and transverse diffusivity and myocyte width (r = 0.96, P < 0.01). Linear regression analysis showed that transverse diffusivities are more affected by changes in myocyte size and nucleus density changes than longitudinal diffusivities, which is consistent with predictions of classical models of diffusion in porous media. Furthermore, primary and secondary DTI eigenvectors during development changed significantly. Collectively, the findings demonstrate a role for DTI to monitor and quantify myocardial development, and potentially cardiac disease. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Osama M Abdullah
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.
| | - Thomas Seidel
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| | - MarJanna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Arnold David Gomez
- Department of Electrical Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Gavin Yiep
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
| | - Julia Cortino
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
| | - Frank B Sachse
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Edward W Hsu
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
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13
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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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14
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Stoeck CT, Kalinowska A, von Deuster C, Harmer J, Chan RW, Niemann M, Manka R, Atkinson D, Sosnovik DE, Mekkaoui C, Kozerke S. Dual-phase cardiac diffusion tensor imaging with strain correction. PLoS One 2014; 9:e107159. [PMID: 25191900 PMCID: PMC4156436 DOI: 10.1371/journal.pone.0107159] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 08/05/2014] [Indexed: 12/03/2022] Open
Abstract
Purpose In this work we present a dual-phase diffusion tensor imaging (DTI) technique that incorporates a correction scheme for the cardiac material strain, based on 3D myocardial tagging. Methods In vivo dual-phase cardiac DTI with a stimulated echo approach and 3D tagging was performed in 10 healthy volunteers. The time course of material strain was estimated from the tagging data and used to correct for strain effects in the diffusion weighted acquisition. Mean diffusivity, fractional anisotropy, helix, transverse and sheet angles were calculated and compared between systole and diastole, with and without strain correction. Data acquired at the systolic sweet spot, where the effects of strain are eliminated, served as a reference. Results The impact of strain correction on helix angle was small. However, large differences were observed in the transverse and sheet angle values, with and without strain correction. The standard deviation of systolic transverse angles was significantly reduced from 35.9±3.9° to 27.8°±3.5° (p<0.001) upon strain-correction indicating more coherent fiber tracks after correction. Myocyte aggregate structure was aligned more longitudinally in systole compared to diastole as reflected by an increased transmural range of helix angles (71.8°±3.9° systole vs. 55.6°±5.6°, p<0.001 diastole). While diastolic sheet angle histograms had dominant counts at high sheet angle values, systolic histograms showed lower sheet angle values indicating a reorientation of myocyte sheets during contraction. Conclusion An approach for dual-phase cardiac DTI with correction for material strain has been successfully implemented. This technique allows assessing dynamic changes in myofiber architecture between systole and diastole, and emphasizes the need for strain correction when sheet architecture in the heart is imaged with a stimulated echo approach.
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Affiliation(s)
- Christian T. Stoeck
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Aleksandra Kalinowska
- Department of Mechanical and Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Constantin von Deuster
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Jack Harmer
- Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Rachel W. Chan
- Centre for Medical Imaging, University College London, London, United Kingdom
| | - Markus Niemann
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Robert Manka
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
- Department of Radiology, University Hospital Zurich, Zurich, Switzerland
| | - David Atkinson
- Centre for Medical Imaging, University College London, London, United Kingdom
| | - David E. Sosnovik
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Choukri Mekkaoui
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Radiology, University Hospital Center of Nîmes, EA 2415, Nîmes, France
- Faculty of Medicine, Montpellier 1 University, Montpellier, France
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
- * E-mail:
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15
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Proteomic profiling of the dystrophin-deficient mdx phenocopy of dystrophinopathy-associated cardiomyopathy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:246195. [PMID: 24772416 PMCID: PMC3977469 DOI: 10.1155/2014/246195] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 02/16/2014] [Indexed: 01/07/2023]
Abstract
Cardiorespiratory complications are frequent symptoms of Duchenne muscular dystrophy, a neuromuscular disorder caused by primary abnormalities in the dystrophin gene. Loss of cardiac dystrophin initially leads to changes in dystrophin-associated glycoproteins and subsequently triggers secondarily sarcolemmal disintegration, fibre necrosis, fibrosis, fatty tissue replacement, and interstitial inflammation. This results in progressive cardiac disease, which is the cause of death in a considerable number of patients afflicted with X-linked muscular dystrophy. In order to better define the molecular pathogenesis of this type of cardiomyopathy, several studies have applied mass spectrometry-based proteomics to determine proteome-wide alterations in dystrophinopathy-associated cardiomyopathy. Proteomic studies included both gel-based and label-free mass spectrometric surveys of dystrophin-deficient heart muscle from the established mdx animal model of dystrophinopathy. Comparative cardiac proteomics revealed novel changes in proteins associated with mitochondrial energy metabolism, glycolysis, signaling, iron binding, antibody response, fibre contraction, basal lamina stabilisation, and cytoskeletal organisation. This review summarizes the importance of studying cardiomyopathy within the field of muscular dystrophy research, outlines key features of the mdx heart and its suitability as a model system for studying cardiac pathogenesis, and discusses the impact of recent proteomic findings for exploring molecular and cellular aspects of cardiac abnormalities in inherited muscular dystrophies.
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16
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Bibee KP, Cheng YJ, Ching JK, Marsh JN, Li AJ, Keeling RM, Connolly AM, Golumbek PT, Myerson JW, Hu G, Chen J, Shannon WD, Lanza GM, Weihl CC, Wickline SA. Rapamycin nanoparticles target defective autophagy in muscular dystrophy to enhance both strength and cardiac function. FASEB J 2014; 28:2047-61. [PMID: 24500923 DOI: 10.1096/fj.13-237388] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Duchenne muscular dystrophy in boys progresses rapidly to severe impairment of muscle function and death in the second or third decade of life. Current supportive therapy with corticosteroids results in a modest increase in strength as a consequence of a general reduction in inflammation, albeit with potential untoward long-term side effects and ultimate failure of the agent to maintain strength. Here, we demonstrate that alternative approaches that rescue defective autophagy in mdx mice, a model of Duchenne muscular dystrophy, with the use of rapamycin-loaded nanoparticles induce a reproducible increase in both skeletal muscle strength and cardiac contractile performance that is not achievable with conventional oral rapamycin, even in pharmacological doses. This increase in physical performance occurs in both young and adult mice, and, surprisingly, even in aged wild-type mice, which sets the stage for consideration of systemic therapies to facilitate improved cell function by autophagic disposal of toxic byproducts of cell death and regeneration.
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Affiliation(s)
- Kristin P Bibee
- 2Center for Translational Research in Advanced Imaging and Nanomedicine, Department of Medicine, Washington University School of Medicine, 660 South Euclid Ave., Saint Louis, MO 63110 USA.
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17
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Li Y, Ge S, Peng Y, Chen X. Inflammation and cardiac dysfunction during sepsis, muscular dystrophy, and myocarditis. BURNS & TRAUMA 2013; 1:109-121. [PMID: 27574633 PMCID: PMC4978107 DOI: 10.4103/2321-3868.123072] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Inflammation plays an important role in cardiac dysfunction under different situations. Acute systemic inflammation occurring in patients with severe burns, trauma, and inflammatory diseases causes cardiac dysfunction, which is one of the leading causes of mortality in these patients. Acute sepsis decreases cardiac contractility and impairs myocardial compliance. Chronic inflammation such as that occurring in Duchenne muscular dystropshy and myocarditis may cause adverse cardiac remodeling including myocyte hypertrophy and death, fibrosis, and altered myocyte function. However, the underlying cellular and molecular mechanisms for inflammatory cardiomyopathy are still controversial probably due to multiple factors involved. Potential mechanisms include the change in circulating blood volume; a direct inhibition of myocyte contractility by cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β); abnormal nitric oxide and reactive oxygen species (ROS) signaling; mitochondrial dysfunction; abnormal excitation-contraction coupling; and reduced calcium sensitivity at the myofibrillar level and blunted β-adrenergic signaling. This review will summarize recent advances in diagnostic technology, mechanisms, and potential therapeutic strategies for inflammation-induced cardiac dysfunction.
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Affiliation(s)
- Ying Li
- Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing, 400038 China
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19040 USA
| | - Shuping Ge
- Drexel University College of Medicine, Philadelphia, Pennsylvania USA
| | - Yizhi Peng
- Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing, 400038 China
| | - Xiongwen Chen
- Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19040 USA
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18
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Koenig X, Rubi L, Obermair GJ, Cervenka R, Dang XB, Lukacs P, Kummer S, Bittner RE, Kubista H, Todt H, Hilber K. Enhanced currents through L-type calcium channels in cardiomyocytes disturb the electrophysiology of the dystrophic heart. Am J Physiol Heart Circ Physiol 2013; 306:H564-H573. [PMID: 24337461 DOI: 10.1152/ajpheart.00441.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Duchenne muscular dystrophy (DMD), induced by mutations in the gene encoding for the cytoskeletal protein dystrophin, is an inherited disease characterized by progressive muscle weakness. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with cardiac complications. These include cardiomyopathy development and cardiac arrhythmias. The current understanding of the pathomechanisms in the heart is very limited, but recent research indicates that dysfunctional ion channels in dystrophic cardiomyocytes play a role. The aim of the present study was to characterize abnormalities in L-type calcium channel function in adult dystrophic ventricular cardiomyocytes. By using the whole cell patch-clamp technique, the properties of currents through calcium channels in ventricular cardiomyocytes isolated from the hearts of normal and dystrophic adult mice were compared. Besides the commonly used dystrophin-deficient mdx mouse model for human DMD, we also used mdx-utr mice, which are both dystrophin- and utrophin-deficient. We found that calcium channel currents were significantly increased, and channel inactivation was reduced in dystrophic cardiomyocytes. Both effects enhance the calcium influx during an action potential (AP). Whereas the AP in dystrophic mouse cardiomyocytes was nearly normal, implementation of the enhanced dystrophic calcium conductance in a computer model of a human ventricular cardiomyocyte considerably prolonged the AP. Finally, the described dystrophic calcium channel abnormalities entailed alterations in the electrocardiograms of dystrophic mice. We conclude that gain of function in cardiac L-type calcium channels may disturb the electrophysiology of the dystrophic heart and thereby cause arrhythmias.
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Affiliation(s)
- Xaver Koenig
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Gerald J Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Rene Cervenka
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Xuan B Dang
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Peter Lukacs
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Stefan Kummer
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Helmut Kubista
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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19
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Sciorati C, Staszewsky L, Zambelli V, Russo I, Salio M, Novelli D, Di Grigoli G, Moresco RM, Clementi E, Latini R. Ibuprofen plus isosorbide dinitrate treatment in the mdx mice ameliorates dystrophic heart structure. Pharmacol Res 2013; 73:35-43. [PMID: 23644256 DOI: 10.1016/j.phrs.2013.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/23/2013] [Accepted: 04/23/2013] [Indexed: 01/16/2023]
Abstract
BACKGROUND Co-administration of ibuprofen (IBU) and isosorbide dinitrate (ISDN) provides synergistic beneficial effects on dystrophic skeletal muscle. Whether this treatment has also cardioprotective effects in this disease was still unknown. AIMS To evaluate the effects of co-administration of IBU and ISDN (a) on left ventricular (LV) structure and function, and (b) on cardiac inflammatory response and fibrosis in mdx mice. METHODS Three groups of mice were studied: mdx mice treated with IBU (50 mg kg⁻¹)+ISDN (30 mg kg⁻¹) administered daily in the diet, mdx mice that received standard diet without drugs and wild type aged-matched mice. Animals were analysed after 10-11 months of treatment. Structural and functional parameters were evaluated by echocardiography while histological analyses were performed to evaluate inflammatory response, collagen deposition, cardiomyocyte number and area. RESULTS Treatment for 10-11 months with IBU+ISDN preserved LV wall thickness and LV mass. Drug treatment also preserved the total number of cardiomyocytes in the LV and attenuated the increase in cardiomyocyte size, when compared to untreated mdx mice. Moreover, a trend towards a decreased number of inflammatory cells, a reduced LV myocardial interstitial fibrosis and an enhanced global LV function response to stress was observed in treated mdx mice. CONCLUSIONS Treatment for 10-11 months with IBU+ISDN is effective in preventing the alterations in LV morphology of mdx mice while not reaching statistical significance on LV function and cardiac inflammation.
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Affiliation(s)
- Clara Sciorati
- Division of Regenerative Medicine, Ospedale San Raffaele Scientific Institute, Via Olgettina 58, Milan, Italy.
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