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Butler D, Reyes DR. Heart-on-a-chip systems: disease modeling and drug screening applications. LAB ON A CHIP 2024; 24:1494-1528. [PMID: 38318723 DOI: 10.1039/d3lc00829k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Cardiovascular disease (CVD) is the leading cause of death worldwide, casting a substantial economic footprint and burdening the global healthcare system. Historically, pre-clinical CVD modeling and therapeutic screening have been performed using animal models. Unfortunately, animal models oftentimes fail to adequately mimic human physiology, leading to a poor translation of therapeutics from pre-clinical trials to consumers. Even those that make it to market can be removed due to unforeseen side effects. As such, there exists a clinical, technological, and economical need for systems that faithfully capture human (patho)physiology for modeling CVD, assessing cardiotoxicity, and evaluating drug efficacy. Heart-on-a-chip (HoC) systems are a part of the broader organ-on-a-chip paradigm that leverages microfluidics, tissue engineering, microfabrication, electronics, and gene editing to create human-relevant models for studying disease, drug-induced side effects, and therapeutic efficacy. These compact systems can be capable of real-time measurements and on-demand characterization of tissue behavior and could revolutionize the drug development process. In this review, we highlight the key components that comprise a HoC system followed by a review of contemporary reports of their use in disease modeling, drug toxicity and efficacy assessment, and as part of multi-organ-on-a-chip platforms. We also discuss future perspectives and challenges facing the field, including a discussion on the role that standardization is expected to play in accelerating the widespread adoption of these platforms.
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Affiliation(s)
- Derrick Butler
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| | - Darwin R Reyes
- Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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2
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Martin TP, MacDonald EA, Bradley A, Watson H, Saxena P, Rog-Zielinska EA, Raheem A, Fisher S, Elbassioni AAM, Almuzaini O, Booth C, Campbell M, Riddell A, Herzyk P, Blyth K, Nixon C, Zentilin L, Berry C, Braun T, Giacca M, McBride MW, Nicklin SA, Cameron ER, Loughrey CM. Ribonucleicacid interference or small molecule inhibition of Runx1 in the border zone prevents cardiac contractile dysfunction following myocardial infarction. Cardiovasc Res 2023; 119:2663-2671. [PMID: 37433039 PMCID: PMC10730241 DOI: 10.1093/cvr/cvad107] [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: 01/13/2023] [Revised: 05/16/2023] [Accepted: 06/11/2023] [Indexed: 07/13/2023] Open
Abstract
AIMS Myocardial infarction (MI) is a major cause of death worldwide. Effective treatments are required to improve recovery of cardiac function following MI, with the aim of improving patient outcomes and preventing progression to heart failure. The perfused but hypocontractile region bordering an infarct is functionally distinct from the remote surviving myocardium and is a determinant of adverse remodelling and cardiac contractility. Expression of the transcription factor RUNX1 is increased in the border zone 1-day after MI, suggesting potential for targeted therapeutic intervention. OBJECTIVE This study sought to investigate whether an increase in RUNX1 in the border zone can be therapeutically targeted to preserve contractility following MI. METHODS AND RESULTS In this work we demonstrate that Runx1 drives reductions in cardiomyocyte contractility, calcium handling, mitochondrial density, and expression of genes important for oxidative phosphorylation. Both tamoxifen-inducible Runx1-deficient and essential co-factor common β subunit (Cbfβ)-deficient cardiomyocyte-specific mouse models demonstrated that antagonizing RUNX1 function preserves the expression of genes important for oxidative phosphorylation following MI. Antagonizing RUNX1 expression via short-hairpin RNA interference preserved contractile function following MI. Equivalent effects were obtained with a small molecule inhibitor (Ro5-3335) that reduces RUNX1 function by blocking its interaction with CBFβ. CONCLUSIONS Our results confirm the translational potential of RUNX1 as a novel therapeutic target in MI, with wider opportunities for use across a range of cardiac diseases where RUNX1 drives adverse cardiac remodelling.
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Affiliation(s)
- Tamara P Martin
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Eilidh A MacDonald
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Ashley Bradley
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Holly Watson
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Priyanka Saxena
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Eva A Rog-Zielinska
- Faculty of Medicine, Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg/Bad Krozingen, 79110 Freiburg, Germany
| | - Anmar Raheem
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Simon Fisher
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Ali Ali Mohamed Elbassioni
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
- Department of Cardiothoracic Surgery, Suez Canal University, 41522 Ismailia, Egypt
| | - Ohood Almuzaini
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Catriona Booth
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Morna Campbell
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Alexandra Riddell
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Pawel Herzyk
- School of Molecular Biosciences, University of Glasgow, Glasgow G12 8QQ, UK
- College of Medical, Veterinary and Life Sciences, Glasgow Polyomics, University of Glasgow, Garscube Campus, Glasgow G61 1BD, UK
| | - Karen Blyth
- School of Cancer Sciences, University of Glasgow, Glasgow G12 0YN, UK
- Cancer Research UK Beatson Institute, Garscube Estate, Glasgow G12 0YN, UK
| | - Colin Nixon
- Cancer Research UK Beatson Institute, Garscube Estate, Glasgow G12 0YN, UK
| | - Lorena Zentilin
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
| | - Colin Berry
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Thomas Braun
- Department of Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Mauro Giacca
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy
- School of Cardiovascular Medicine and Sciences, King’s College London British Heart Foundation Centre, London WC2R 2LS, UK
| | - Martin W McBride
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Stuart A Nicklin
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
| | - Ewan R Cameron
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow G12 0YN, UK
| | - Christopher M Loughrey
- British Heart Foundation Glasgow Cardiovascular Research Centre, School of Cardiovascular and Metabolic Health, University of Glasgow, University Place, Glasgow G12 8TA, UK
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3
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Onishi R, Ueda J, Ide S, Koseki M, Sakata Y, Saito S. Application of Magnetic Resonance Strain Analysis Using Feature Tracking in a Myocardial Infarction Model. Tomography 2023; 9:871-882. [PMID: 37104142 PMCID: PMC10141923 DOI: 10.3390/tomography9020071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/04/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023] Open
Abstract
This study validates the usefulness of myocardial strain analysis with cardiac cine magnetic resonance imaging (MRI) by evaluating the changes in the cardiac function and myocardial strain values longitudinally in a myocardial disease model. Six eight-week-old male Wistar rats were used as a model of myocardial infarction (MI). Cine images were taken in the short axis, two-chamber view longitudinal axis, and four-chamber view longitudinal axis directions in rats 3 and 9 days after MI and in control rats, with preclinical 7-T MRI. The control images and the images on days 3 and 9 were evaluated by measuring the ventricular ejection fraction (EF) and the strain values in the circumferential (CS), radial (RS), and longitudinal directions (LS). The CS decreased significantly 3 days after MI, but there was no difference between the images on days 3 and 9. The two-chamber view LS was -9.7 ± 2.1% at 3 days and -13.9 ± 1.4% at 9 days after MI. The four-chamber view LS was -9.9 ± 1.5% at 3 days and -11.9 ± 1.3% at 9 days after MI. Both the two- and four-chamber LS values were significantly decreased 3 days after MI. Myocardial strain analysis is, therefore, useful for assessing the pathophysiology of MI.
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Affiliation(s)
- Ryutaro Onishi
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
- Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto 606-8507, Japan
| | - Junpei Ueda
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Seiko Ide
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Masahiro Koseki
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Shigeyoshi Saito
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
- Department of Advanced Medical Technologies, National Cerebral and Cardiovascular Center Research Institute, Osaka 564-8565, Japan
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4
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Rexius-Hall ML, Khalil NN, Escopete SS, Li X, Hu J, Yuan H, Parker SJ, McCain ML. A myocardial infarct border-zone-on-a-chip demonstrates distinct regulation of cardiac tissue function by an oxygen gradient. SCIENCE ADVANCES 2022; 8:eabn7097. [PMID: 36475790 PMCID: PMC9728975 DOI: 10.1126/sciadv.abn7097] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
After a myocardial infarction, the boundary between the injured, hypoxic tissue and the adjacent viable, normoxic tissue, known as the border zone, is characterized by an oxygen gradient. Yet, the impact of an oxygen gradient on cardiac tissue function is poorly understood, largely due to limitations of existing experimental models. Here, we engineered a microphysiological system to controllably expose engineered cardiac tissue to an oxygen gradient that mimics the border zone and measured the effects of the gradient on electromechanical function and the transcriptome. The gradient delayed calcium release, reuptake, and propagation; decreased diastolic and peak systolic stress; and increased expression of inflammatory cascades that are hallmarks of myocardial infarction. These changes were distinct from those observed in tissues exposed to uniform normoxia or hypoxia, demonstrating distinct regulation of cardiac tissue phenotypes by an oxygen gradient. Our border-zone-on-a-chip model advances functional and mechanistic insight into oxygen-dependent cardiac tissue pathophysiology.
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Affiliation(s)
- Megan L. Rexius-Hall
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Natalie N. Khalil
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Sean S. Escopete
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Xin Li
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Jiayi Hu
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Hongyan Yuan
- Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Sarah J. Parker
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Megan L. McCain
- Laboratory for Living Systems Engineering, Department of Biomedical Engineering, USC Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
- Corresponding author.
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5
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Huang H, Chang WT, Huang CC. High-Spatiotemporal-Resolution Visualization of Myocardial Strains Through Vector Doppler Estimation: A Small-Animal Study. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:1859-1870. [PMID: 35108204 DOI: 10.1109/tuffc.2022.3148873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
High-frequency ultrasound (HFUS) imaging is extensively used for cardiac diseases in small animals due to its high spatial resolution. However, there is a lack of a system that can provide a 2-D high-spatiotemporal dynamic visualization of mouse myocardial strains. In this article, a dynamic HFUS (40 MHz) high-resolution strain imaging was developed through the vector Doppler imaging. Following in vitro tests using a rubber balloon phantom, in vivo experiments were performed on wild-type (WT) and myocardial infarction (MI) mice. High-resolution dynamic images of myocardial strains were obtained in the longitudinal, radial, and circumferential directions at a frame rate of 1 kHz. Global peak strain values for WT mice were -19.3% ± 1.3% (longitudinal), 31.4% ± 1.7% (radial in the long axis), -19.9% ±.8% (circumferential), and 34.4% ± 1.9% (radial in the short axis); those for the MI mice were -16.1% ±.9% (longitudinal), 26.8% ± 2.9% (radial in the long axis), -15.2% ± 2.7% (circumferential), and 21.6% ± 4.8% (radial in the short axis). These results indicate that the strains for MI mice are significantly lower than those for WT mice. Regional longitudinal strain curves in the epicardial, midcardial, and endocardial layers were measured and the peak strain values for WT mice were -22.% and -16.8% in the endocardial and epicardial layers, respectively. However, no significant difference in the layer-based values was noted for the MI mice. Regional analysis results revealed obvious myocardial strain variation in the apical anterior region in the MI mice. The experimental results demonstrate that the proposed dynamic cardiac strain imaging can be useful in high-performance imaging of small-animal cardiac diseases.
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6
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Martin TP, MacDonald EA, Elbassioni AAM, O'Toole D, Zaeri AAI, Nicklin SA, Gray GA, Loughrey CM. Preclinical models of myocardial infarction: from mechanism to translation. Br J Pharmacol 2021; 179:770-791. [PMID: 34131903 DOI: 10.1111/bph.15595] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 11/28/2022] Open
Abstract
Approximately 7 million people are affected by acute myocardial infarction (MI) each year, and despite significant therapeutic and diagnostic advancements, MI remains a leading cause of mortality worldwide. Preclinical animal models have significantly advanced our understanding of MI and have enabled the development of therapeutic strategies to combat this debilitating disease. Notably, some drugs currently used to treat MI and heart failure (HF) in patients had initially been studied in preclinical animal models. Despite this, preclinical models are limited in their ability to fully reproduce the complexity of MI in humans. The preclinical model must be carefully selected to maximise the translational potential of experimental findings. This review describes current experimental models of MI and considers how they have been used to understand drug mechanisms of action and support translational medicine development.
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Affiliation(s)
- Tamara P Martin
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Eilidh A MacDonald
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Ali Ali Mohamed Elbassioni
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK.,Suez Canal University, Arab Republic of Egypt
| | - Dylan O'Toole
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Ali Abdullah I Zaeri
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Stuart A Nicklin
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
| | - Gillian A Gray
- Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, UK
| | - Christopher M Loughrey
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, UK
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7
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Shin HS, Shin HH, Shudo Y. Current Status and Limitations of Myocardial Infarction Large Animal Models in Cardiovascular Translational Research. Front Bioeng Biotechnol 2021; 9:673683. [PMID: 33996785 PMCID: PMC8116580 DOI: 10.3389/fbioe.2021.673683] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/06/2021] [Indexed: 01/16/2023] Open
Abstract
Establishing an appropriate disease model that mimics the complexities of human cardiovascular disease is critical for evaluating the clinical efficacy and translation success. The multifaceted and complex nature of human ischemic heart disease is difficult to recapitulate in animal models. This difficulty is often compounded by the methodological biases introduced in animal studies. Considerable variations across animal species, modifications made in surgical procedures, and inadequate randomization, sample size calculation, blinding, and heterogeneity of animal models used often produce preclinical cardiovascular research that looks promising but is irreproducible and not translatable. Moreover, many published papers are not transparent enough for other investigators to verify the feasibility of the studies and the therapeutics' efficacy. Unfortunately, successful translation of these innovative therapies in such a closed and biased research is difficult. This review discusses some challenges in current preclinical myocardial infarction research, focusing on the following three major inhibitors for its successful translation: Inappropriate disease model, frequent modifications to surgical procedures, and insufficient reporting transparency.
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Affiliation(s)
- Hye Sook Shin
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Heather Hyeyoon Shin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Yasuhiro Shudo
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
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Perotti LE, Verzhbinsky IA, Moulin K, Cork TE, Loecher M, Balzani D, Ennis DB. Estimating cardiomyofiber strain in vivo by solving a computational model. Med Image Anal 2021; 68:101932. [PMID: 33383331 PMCID: PMC7956226 DOI: 10.1016/j.media.2020.101932] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 11/22/2020] [Accepted: 11/27/2020] [Indexed: 11/19/2022]
Abstract
Since heart contraction results from the electrically activated contraction of millions of cardiomyocytes, a measure of cardiomyocyte shortening mechanistically underlies cardiac contraction. In this work we aim to measure preferential aggregate cardiomyocyte ("myofiber") strains based on Magnetic Resonance Imaging (MRI) data acquired to measure both voxel-wise displacements through systole and myofiber orientation. In order to reduce the effect of experimental noise on the computed myofiber strains, we recast the strains calculation as the solution of a boundary value problem (BVP). This approach does not require a calibrated material model, and consequently is independent of specific myocardial material properties. The solution to this auxiliary BVP is the displacement field corresponding to assigned values of myofiber strains. The actual myofiber strains are then determined by minimizing the difference between computed and measured displacements. The approach is validated using an analytical phantom, for which the ground-truth solution is known. The method is applied to compute myofiber strains using in vivo displacement and myofiber MRI data acquired in a mid-ventricular left ventricle section in N=8 swine subjects. The proposed method shows a more physiological distribution of myofiber strains compared to standard approaches that directly differentiate the displacement field.
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Affiliation(s)
- Luigi E Perotti
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL, USA.
| | - Ilya A Verzhbinsky
- Department of Radiology, Stanford University, Stanford, CA, USA; Medical Scientist Training Program, University of California, San Diego, La Jolla, USA
| | - Kévin Moulin
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Tyler E Cork
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Michael Loecher
- Department of Radiology, Stanford University, Stanford, CA, USA
| | - Daniel Balzani
- Chair of Continuum Mechanics, Ruhr University Bochum, Bochum, Germany
| | - Daniel B Ennis
- Department of Radiology, Stanford University, Stanford, CA, USA
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9
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Wu YL. Cardiac MRI Assessment of Mouse Myocardial Infarction and Regeneration. Methods Mol Biol 2021; 2158:81-106. [PMID: 32857368 DOI: 10.1007/978-1-0716-0668-1_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Small animal models are indispensable for cardiac regeneration research. Studies in mouse and rat models have provided important insights into the etiology and mechanisms of cardiovascular diseases and accelerated the development of therapeutic strategies. It is vitally important to be able to evaluate the therapeutic efficacy and have reliable surrogate markers for therapeutic development for cardiac regeneration research. Magnetic resonance imaging (MRI), a versatile and noninvasive imaging modality with excellent penetration depth, tissue coverage, and soft-tissue contrast, is becoming a more important tool in both clinical settings and research arenas. Cardiac MRI (CMR) is versatile, noninvasive, and capable of measuring many different aspects of cardiac functions, and, thus, is ideally suited to evaluate therapeutic efficacy for cardiac regeneration. CMR applications include assessment of cardiac anatomy, regional wall motion, myocardial perfusion, myocardial viability, cardiac function assessment, assessment of myocardial infarction, and myocardial injury. Myocardial infarction models in mice are commonly used model systems for cardiac regeneration research. In this chapter, we discuss various CMR applications to evaluate cardiac functions and inflammation after myocardial infarction.
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Affiliation(s)
- Yijen L Wu
- Department of Developmental Biology, Rangos Research Center Animal Imaging Core, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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10
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Li DS, Avazmohammadi R, Rodell CB, Hsu EW, Burdick JA, Gorman JH, Gorman RC, Sacks MS. How hydrogel inclusions modulate the local mechanical response in early and fully formed post-infarcted myocardium. Acta Biomater 2020; 114:296-306. [PMID: 32739434 PMCID: PMC7484038 DOI: 10.1016/j.actbio.2020.07.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/23/2022]
Abstract
Expansion of myocardium after myocardial infarction (MI) has long been identified as the primary mechanism that drives adverse left ventricular (LV) remodeling towards heart failure and death. Direct injection of hydrogels into the myocardium to mechanically constrain the infarct has demonstrated promise in limiting its remodeling and expansion. Despite early successes, there remain open questions in the determination of optimal hydrogel therapies, key application characteristics for which include injected polymer volume, stiffness, and spatial placement. Addressing these questions is complicated by the substantial variations in infarct type and extent, as well as limited understanding of the underlying mechanisms. Herein, we present an investigation on how hydrogel inclusions affect the effective tissue-level stiffness and strain fields in myocardium using full three-dimensional (3D) finite element simulations at early and late post-MI time points. We calibrated our simulations to triaxial mechanical and structural measurements of cuboidal LV myocardial specimens of post-infarcted myocardium, 0 and 4 weeks post-MI, injected with a dual-crosslinking hyaluronic acid-based hydrogel. Simulations included multiple deformation modes that spanned the anticipated physiological range in order to assess the effects of variations in inclusion size, location, and modulus on tissue-level myocardial mechanics. We observed significant local stiffening in the hydrogel-injected specimens that was highly dependent on the volume and mechanical properties of the injected hydrogel. Simulations revealed that the primary effect of the injections under physiological loading was a reduction in myocardial strain. This result suggests that hydrogel injections reduce infarct expansion by limiting the peak strains over the cardiac cycle. Overall, our study indicated that modulation of local effective tissue stiffness and corresponding strain reduction are governed by the volume and stiffness of the hydrogel, but relatively insensitive to its transmural placement. These findings provide important insights into mechanisms for ameliorating post-MI remodeling, as well as guidance for the future design of post-MI therapies.
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Affiliation(s)
- David S Li
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Reza Avazmohammadi
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA; Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Christopher B Rodell
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA; Polymeric Biomaterials Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Edward W Hsu
- Preclinical Imaging Core Facility, Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Jason A Burdick
- Polymeric Biomaterials Laboratory, Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Perelman School of Medicine, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Perelman School of Medicine, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael S Sacks
- James T. Willerson Center for Cardiovascular Modeling and Simulation, Oden Institute for Computational Engineering and Sciences, Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
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11
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Shah SA, Cui SX, Waters CD, Sano S, Wang Y, Doviak H, Leor J, Walsh K, French BA, Epstein FH. Nitroxide-enhanced MRI of cardiovascular oxidative stress. NMR IN BIOMEDICINE 2020; 33:e4359. [PMID: 32648316 PMCID: PMC7904044 DOI: 10.1002/nbm.4359] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 04/08/2020] [Accepted: 06/03/2020] [Indexed: 06/07/2023]
Abstract
BACKGROUND In vivo imaging of oxidative stress can facilitate the understanding and treatment of cardiovascular diseases. We evaluated nitroxide-enhanced MRI with 3-carbamoyl-proxyl (3CP) for the detection of myocardial oxidative stress. METHODS Three mouse models of cardiac oxidative stress were imaged, namely angiotensin II (Ang II) infusion, myocardial infarction (MI), and high-fat high-sucrose (HFHS) diet-induced obesity (DIO). For the Ang II model, mice underwent MRI at baseline and after 7 days of Ang II (n = 8) or saline infusion (n = 8). For the MI model, mice underwent MRI at baseline (n = 10) and at 1 (n = 8), 4 (n = 9), and 21 (n = 8) days after MI. For the HFHS-DIO model, mice underwent MRI at baseline (n = 20) and 18 weeks (n = 13) after diet initiation. The 3CP reduction rate, Kred , computed using a tracer kinetic model, was used as a metric of oxidative stress. Dihydroethidium (DHE) staining of tissue sections was performed on Day 1 after MI. RESULTS For the Ang II model, Kred was higher after 7 days of Ang II versus other groups (p < 0.05). For the MI model, Kred , in the infarct region was significantly elevated on Days 1 and 4 after MI (p < 0.05), whereas Kred in the noninfarcted region did not change after MI. DHE confirmed elevated oxidative stress in the infarct zone on Day 1 after MI. After 18 weeks of HFHS diet, Kred was higher in mice after diet versus baseline (p < 0.05). CONCLUSIONS Nitroxide-enhanced MRI noninvasively quantifies tissue oxidative stress as one component of a multiparametric preclinical MRI examination. These methods may facilitate investigations of oxidative stress in cardiovascular disease and related therapies.
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Affiliation(s)
- Soham A Shah
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Sophia X Cui
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | | | - Soichi Sano
- Hematovascular Biology Center, Robert M. Berne Cardiovascular Research Center, University of Virginia, Virginia, USA
| | - Ying Wang
- Hematovascular Biology Center, Robert M. Berne Cardiovascular Research Center, University of Virginia, Virginia, USA
| | - Heather Doviak
- Hematovascular Biology Center, Robert M. Berne Cardiovascular Research Center, University of Virginia, Virginia, USA
| | - Jonathan Leor
- Neufield Cardiac Research Institute, Sheba Medical Center, Tel-Aviv University, Tel-Hashomer, Ramat Gan, Israel
| | - Kenneth Walsh
- Hematovascular Biology Center, Robert M. Berne Cardiovascular Research Center, University of Virginia, Virginia, USA
| | - Brent A French
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Frederick H Epstein
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
- Radiology, University of Virginia, Charlottesville, Virginia, USA
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12
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Yang Y, Lei D, Huang S, Yang Q, Song B, Guo Y, Shen A, Yuan Z, Li S, Qing F, Ye X, You Z, Zhao Q. Elastic 3D-Printed Hybrid Polymeric Scaffold Improves Cardiac Remodeling after Myocardial Infarction. Adv Healthc Mater 2019; 8:e1900065. [PMID: 30941925 DOI: 10.1002/adhm.201900065] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/22/2019] [Indexed: 01/12/2023]
Abstract
Myocardial remodeling, including ventricular dilation and wall thinning, is an important pathological process caused by myocardial infarction (MI). To intervene in this pathological process, a new type of cardiac scaffold composed of a thermoset (poly-[glycerol sebacate], PGS) and a thermoplastic (poly-[ε-caprolactone], PCL) is directly printed by employing fused deposition modeling 3D-printing technology. The PGS-PCL scaffold possesses stacked construction with regular crisscrossed filaments and interconnected micropores and exhibits superior mechanical properties. In vitro studies demonstrate favorable biodegradability and biocompatibility of the PGS-PCL scaffold. When implanted onto the infarcted myocardium, this scaffold improves and preserves heart function. Furthermore, the scaffold improves several vital aspects of myocardial remodeling. On the morphological level, the scaffold reduces ventricular wall thinning and attenuated infarct size, and on the cellular level, it enhances vascular density and increases M2 macrophage infiltration, which might further contribute to the mitigated myocardial apoptosis rate. Moreover, the flexible PGS-PCL scaffold can be tailored to any desired shape, showing promise for annular-shaped restraint device application and meeting the demands for minimal invasive operation. Overall, this study demonstrates the therapeutic effects and versatile applications of a novel 3D-printed, biodegradable and biocompatible cardiac scaffold, which represents a promising strategy for improving myocardial remodeling after MI.
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Affiliation(s)
- Yang Yang
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
| | - Dong Lei
- College of ChemistryChemical Engineering and BiotechnologyDonghua University Shanghai 201620 P. R. China
| | - Shixing Huang
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
| | - Qi Yang
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
| | - Benyan Song
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsInternational Joint Laboratory for Advanced Fiber and Low‐Dimension MaterialsCollege of Materials Science and EngineeringDonghua University Shanghai 201620 P. R. China
| | - Yifan Guo
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsInternational Joint Laboratory for Advanced Fiber and Low‐Dimension MaterialsCollege of Materials Science and EngineeringDonghua University Shanghai 201620 P. R. China
| | - Ao Shen
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsInternational Joint Laboratory for Advanced Fiber and Low‐Dimension MaterialsCollege of Materials Science and EngineeringDonghua University Shanghai 201620 P. R. China
| | - Zhize Yuan
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
| | - Sen Li
- Department of Vascular SurgeryThe Second Affiliated Hospital of Zhejiang University School of MedicineZhejiang University School of Medicine Zhejiang 310009 P. R. China
| | - Feng‐Ling Qing
- College of ChemistryChemical Engineering and BiotechnologyDonghua University Shanghai 201620 P. R. China
| | - Xiaofeng Ye
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
| | - Zhengwei You
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsInternational Joint Laboratory for Advanced Fiber and Low‐Dimension MaterialsCollege of Materials Science and EngineeringDonghua University Shanghai 201620 P. R. China
| | - Qiang Zhao
- Department of Cardiac SurgeryRuijin HospitalShanghai Jiaotong University School of Medicine Shanghai 200025 P. R. China
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13
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Wang H, Rodell CB, Zhang X, Dusaj NN, Gorman JH, Pilla JJ, Jackson BM, Burdick JA, Gorman RC, Wenk JF. Effects of hydrogel injection on borderzone contractility post-myocardial infarction. Biomech Model Mechanobiol 2018; 17:1533-1542. [PMID: 29855734 PMCID: PMC10538855 DOI: 10.1007/s10237-018-1039-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 05/22/2018] [Indexed: 01/19/2023]
Abstract
Injectable hydrogels are a potential therapy for mitigating adverse left ventricular (LV) remodeling after myocardial infarction (MI). Previous studies using magnetic resonance imaging (MRI) have shown that hydrogel treatment improves systolic strain in the borderzone (BZ) region surrounding the infarct. However, the corresponding contractile properties of the BZ myocardium are still unknown. The goal of the current study was to quantify the in vivo contractile properties of the BZ myocardium post-MI in an ovine model treated with an injectable hydrogel. Contractile properties were determined 8 weeks following posterolateral MI by minimizing the difference between in vivo strains and volume calculated from MRI and finite element model predicted strains and volume. This was accomplished by using a combination of MRI, catheterization, finite element modeling, and numerical optimization. Results show contractility in the BZ of animals treated with hydrogel injection was significantly higher than untreated controls. End-systolic (ES) fiber stress was also greatly reduced in the BZ of treated animals. The passive stiffness of the treated infarct region was found to be greater than the untreated control. Additionally, the wall thickness in the infarct and BZ regions was found to be significantly higher in the treated animals. Treatment with hydrogel injection significantly improved BZ function and reduced LV remodeling, via altered MI properties. These changes are linked to a reduction in the ES fiber stress in the BZ myocardium surrounding the infarct. The current results imply that injectable hydrogels could be a viable therapy for maintaining LV function post-MI.
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Affiliation(s)
- Hua Wang
- Department of Mechanical Engineering, University of Kentucky, 269 Ralph G. Anderson Building, Lexington, KY, 40506-0503, USA
- Department of Mechanical Engineering, Ludong University, Yantai, Shandong, China
| | - Christopher B Rodell
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Xiaoyan Zhang
- Department of Mechanical Engineering, University of Kentucky, 269 Ralph G. Anderson Building, Lexington, KY, 40506-0503, USA
| | - Neville N Dusaj
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - James J Pilla
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Benjamin M Jackson
- Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Surgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jonathan F Wenk
- Department of Mechanical Engineering, University of Kentucky, 269 Ralph G. Anderson Building, Lexington, KY, 40506-0503, USA.
- Department of Surgery, University of Kentucky, Lexington, KY, 40506, USA.
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14
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Kronenbitter A, Funk F, Hackert K, Gorreßen S, Glaser D, Boknik P, Poschmann G, Stühler K, Isić M, Krüger M, Schmitt JP. Impaired Ca 2+ cycling of nonischemic myocytes contributes to sarcomere dysfunction early after myocardial infarction. J Mol Cell Cardiol 2018; 119:28-39. [PMID: 29674140 DOI: 10.1016/j.yjmcc.2018.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/05/2018] [Accepted: 04/08/2018] [Indexed: 12/15/2022]
Abstract
Changes in the nonischemic remote myocardium of the heart contribute to left ventricular dysfunction after ischemia and reperfusion (I/R). Understanding the underlying mechanisms early after I/R is crucial to improve the adaptation of the viable myocardium to increased mechanical demands. Here, we investigated the role of myocyte Ca2+ handling in the remote myocardium 24 h after 60 min LAD occlusion. Cardiomyocytes isolated from the basal noninfarct-related parts of wild type mouse hearts demonstrated depressed beat-to-beat Ca2+ handling. The amplitude of the Ca2+ transients as well as the kinetics of Ca2+ transport were reduced by up to 25%. These changes were associated with impaired sarcomere contraction. While expression levels of Ca2+ regulatory proteins were unchanged in remote myocardium compared to the corresponding regions of sham-operated hearts, mobility shift analyses of phosphorylated protein showed 2.9 ± 0.4-fold more unphosphorylated phospholamban (PLN) monomers, the PLN species that inhibits the Ca2+ ATPase SERCA2a (P ≤ 0.001). Phospho-specific antibodies revealed normal phosphorylation of PLN at T17 in remote myocardium, but markedly reduced phosphorylation at its PKA-dependent phosphorylation site, S16 (P ≤ 0.01). The underlying cause involved enhanced activity of protein phosphatases, particularly PP2A (P ≤ 0.01). In contrast, overall PKA activity was normal. The PLN interactome, as determined by co-immunoprecipitation and mass spectrometry, and the phosphorylation state of PKA targets other than PLN were also unchanged. Isoproterenol enhanced cellular Ca2+ cycling much stronger in remote myocytes than in healthy controls and improved sarcomere function. We conclude that the reduced phosphorylation state of PLN at S16 impairs myocyte Ca2+ cycling in the remote myocardium 24 h after I/R and contributes to contractile dysfunction.
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Affiliation(s)
- Annette Kronenbitter
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Florian Funk
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Katarzyna Hackert
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Simone Gorreßen
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Dennis Glaser
- Institute of Pharmacology and Toxicology, University Hospital Münster, Germany
| | - Peter Boknik
- Institute of Pharmacology and Toxicology, University Hospital Münster, Germany
| | - Gereon Poschmann
- Molecular Proteomics Laboratory, Biological and Medical Research Center (BMFZ), Institute of Molecular Medicine, University Hospital Düsseldorf, Germany
| | - Kai Stühler
- Molecular Proteomics Laboratory, Biological and Medical Research Center (BMFZ), Institute of Molecular Medicine, University Hospital Düsseldorf, Germany
| | - Malgorzata Isić
- Institute of Cardiovascular Physiology, University of Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Martina Krüger
- Institute of Cardiovascular Physiology, University of Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany.
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15
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Constantinides C, Murphy K. Molecular and Integrative Physiological Effects of Isoflurane Anesthesia: The Paradigm of Cardiovascular Studies in Rodents using Magnetic Resonance Imaging. Front Cardiovasc Med 2016; 3:23. [PMID: 27525256 PMCID: PMC4965459 DOI: 10.3389/fcvm.2016.00023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/04/2016] [Indexed: 12/19/2022] Open
Abstract
To-this-date, the exact molecular, cellular, and integrative physiological mechanisms of anesthesia remain largely unknown. Published evidence indicates that anesthetic effects are multifocal and occur in a time-dependent and coordinated manner, mediated via central, local, and peripheral pathways. Their effects can be modulated by a range of variables, and their elicited end-effect on the integrative physiological response is highly variable. This review summarizes the major cellular and molecular sites of anesthetic action with a focus on the paradigm of isoflurane (ISO) - the most commonly used anesthetic nowadays - and its use in prolonged in vivo rodent studies using imaging modalities, such as magnetic resonance imaging (MRI). It also presents established evidence for normal ranges of global and regional physiological cardiac function under ISO, proposes optimal, practical methodologies relevant to the use of anesthetic protocols for MRI and outlines the beneficial effects of nitrous oxide supplementation.
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Affiliation(s)
- Christakis Constantinides
- Chi Biomedical Ltd., Nicosia, Cyprus; Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Kathy Murphy
- Division of Biomedical Sciences, University of Oxford , Oxford , UK
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16
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Joubert M, Hardouin J, Legallois D, Blanchart K, Elie N, Nowoczyn M, Croisille P, Coulbault L, Bor-Angelier C, Allouche S, Manrique A. Effects of glycaemic variability on cardiac remodelling after reperfused myocardial infarction: Evaluation of streptozotocin-induced diabetic Wistar rats using cardiac magnetic resonance imaging. DIABETES & METABOLISM 2016; 42:342-350. [PMID: 26971835 DOI: 10.1016/j.diabet.2016.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/27/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
AIMS In addition to hyperglycaemia, glycaemic variability seems to be associated with poor outcomes after acute myocardial infarction. This study explored the impact of glycaemic variability in diabetic Wistar rats subjected to myocardial ischaemia/reperfusion. METHODS Animals with streptozotocin-induced diabetes received insulin either to maintain stable hyperglycaemia (Dh group) or to generate glycaemic variability (Dv). After experimental myocardial ischaemia/reperfusion was surgically induced, 7T cardiac magnetic resonance imaging (CMR) was performed at weeks 1 (w1) and 3 (w3). RESULTS Twenty-six rats were randomized [sham group (S): n=5; control group (C): n=7; Dh group: n=6; and Dv group: n=8]. The mean amplitude of glucose reflecting glycaemic variability was higher in the Dv than in the Dh group (9.1±2.7mmol/L vs 5.9±1.9mmol/L; P<0.05). CMR assessment at w3 revealed ventricular enlargement in both Dh and Dv groups compared with the C and S groups (end-diastolic volume: 1.60±0.22 and 1.36±0.30mL/kg compared with 1.11±0.13 and 0.87±0.11mL/kg, respectively; P<0.05). Circumferential strain was altered between w1 and w3 in the remote area only in the Dv group, resulting in a lower value in this group than in the S, C and Dh groups (-0.11±0.01 vs -0.17±0.05, -0.15±0.03 and -0.16±0.03, respectively; P<0.05). In addition, at w3, oedema was also higher in the remote area in the Dv than in the C group (18.3±4.9ms vs 14.5±1.7ms, respectively; P<0.05). CONCLUSION In the context of experimental myocardial ischaemia/reperfusion, our results suggest that glycaemic variability might have a potentially deleterious impact on myocardial outcomes beyond the classical glucose metrics.
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Affiliation(s)
- M Joubert
- Diabetes Care Unit, Caen University Hospital, Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - J Hardouin
- Diabetes Care Unit, Caen University Hospital, Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - D Legallois
- Cardiology Unit, Caen University Hospital, 14033 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - K Blanchart
- Cardiology Unit, Caen University Hospital, 14033 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - N Elie
- CMABIO-HIQ Facility, SF4206 ICORE, IBFA, University of Caen, 14000 Caen, France.
| | - M Nowoczyn
- Biochemistry Unit, Caen University Hospital, 14000 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - P Croisille
- Radiology Department, Saint-Etienne University Hospital, 42000 Saint-Etienne, France; CREATIS CNRS UMR5220 Inserm U1044, Lyon University, 69000 Lyon, France.
| | - L Coulbault
- Biochemistry Unit, Caen University Hospital, 14000 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - C Bor-Angelier
- Pathology Department, F.-Baclesse Cancer Center, 14000 Caen, France.
| | - S Allouche
- Biochemistry Unit, Caen University Hospital, 14000 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
| | - A Manrique
- Nuclear Medicine Department, Caen University Hospital, 14033 Caen, France; EA4650 Normandie université, GIP Cyceron, 14000 Caen, France.
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17
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Santos A, Fernández-Friera L, Villalba M, López-Melgar B, España S, Mateo J, Mota RA, Jiménez-Borreguero J, Ruiz-Cabello J. Cardiovascular imaging: what have we learned from animal models? Front Pharmacol 2015; 6:227. [PMID: 26539113 PMCID: PMC4612690 DOI: 10.3389/fphar.2015.00227] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/22/2015] [Indexed: 12/17/2022] Open
Abstract
Cardiovascular imaging has become an indispensable tool for patient diagnosis and follow up. Probably the wide clinical applications of imaging are due to the possibility of a detailed and high quality description and quantification of cardiovascular system structure and function. Also phenomena that involve complex physiological mechanisms and biochemical pathways, such as inflammation and ischemia, can be visualized in a non-destructive way. The widespread use and evolution of imaging would not have been possible without animal studies. Animal models have allowed for instance, (i) the technical development of different imaging tools, (ii) to test hypothesis generated from human studies and finally, (iii) to evaluate the translational relevance assessment of in vitro and ex-vivo results. In this review, we will critically describe the contribution of animal models to the use of biomedical imaging in cardiovascular medicine. We will discuss the characteristics of the most frequent models used in/for imaging studies. We will cover the major findings of animal studies focused in the cardiovascular use of the repeatedly used imaging techniques in clinical practice and experimental studies. We will also describe the physiological findings and/or learning processes for imaging applications coming from models of the most common cardiovascular diseases. In these diseases, imaging research using animals has allowed the study of aspects such as: ventricular size, shape, global function, and wall thickening, local myocardial function, myocardial perfusion, metabolism and energetic assessment, infarct quantification, vascular lesion characterization, myocardial fiber structure, and myocardial calcium uptake. Finally we will discuss the limitations and future of imaging research with animal models.
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Affiliation(s)
- Arnoldo Santos
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Madrid-MIT M+Visión Consortium Madrid, Spain ; Department of Anesthesia, Massachusetts General Hospital, Harvard Medical School Boston, MA, USA
| | - Leticia Fernández-Friera
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Hospital Universitario HM Monteprincipe Madrid, Spain
| | - María Villalba
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain
| | - Beatriz López-Melgar
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Hospital Universitario HM Monteprincipe Madrid, Spain
| | - Samuel España
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Madrid-MIT M+Visión Consortium Madrid, Spain
| | - Jesús Mateo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain
| | - Ruben A Mota
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Charles River Barcelona, Spain
| | - Jesús Jiménez-Borreguero
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Cardiac Imaging Department, Hospital de La Princesa Madrid, Spain
| | - Jesús Ruiz-Cabello
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Universidad Complutense de Madrid Madrid, Spain
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18
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Protti A, Lavin B, Dong X, Lorrio S, Robinson S, Onthank D, Shah AM, Botnar RM. Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI). J Am Heart Assoc 2015; 4:e001851. [PMID: 26272655 PMCID: PMC4599453 DOI: 10.1161/jaha.115.001851] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin–specific contrast agent (Gd-ESMA) was used to image tropoelastin and mature elastin fibers for in vivo assessment of extracellular matrix remodeling post-MI. Methods and Results Gd-ESMA enhancement was studied in a mouse model of myocardial infarction using a 7 T MRI scanner and results were compared to those achieved after injection of a nonspecific control contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the infarcted tissue, Gd-ESMA uptake (measured as R1 relaxation rate) steadily increased from day 3 to day 21 as a result of the synthesis of elastin/tropoelastin. R1 values were in good agreement with histological findings. A similar R1 behavior was observed in the remote myocardium. No mature cross-linked elastin was found at any time point. In contrast, Gd-DTPA uptake was only observed in the infarct with no changes in R1 values between 3 and 21 days post-MI. Conclusions We demonstrate the feasibility of in vivo imaging of extracellular matrix remodeling post-MI using a tropoelastin/elastin binding MR contrast agent, Gd-ESMA. We found that tropoelastin is the main contributor to the increased MRI signal at late stages of MI where its augmentation in areas of infarction was in good agreement with the R1 increase.
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Affiliation(s)
- Andrea Protti
- Cardiovascular Division, James Black Centre, King's College Hospital, London, United Kingdom (A.P., X.D., A.M.S.) Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom (A.P., B.L., S.L., R.M.B.) Cardiovascular Division, The British Heart Foundation Centre of Excellence, King's College London, London, United Kingdom (A.P., B.L., A.M.S., R.M.B.)
| | - Begoña Lavin
- Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom (A.P., B.L., S.L., R.M.B.) Cardiovascular Division, The British Heart Foundation Centre of Excellence, King's College London, London, United Kingdom (A.P., B.L., A.M.S., R.M.B.)
| | - Xuebin Dong
- Cardiovascular Division, James Black Centre, King's College Hospital, London, United Kingdom (A.P., X.D., A.M.S.)
| | - Silvia Lorrio
- Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom (A.P., B.L., S.L., R.M.B.)
| | - Simon Robinson
- Lantheus Medical Imaging, North Billerica, MA (S.R., D.O.)
| | - David Onthank
- Lantheus Medical Imaging, North Billerica, MA (S.R., D.O.)
| | - Ajay M Shah
- Cardiovascular Division, James Black Centre, King's College Hospital, London, United Kingdom (A.P., X.D., A.M.S.) Cardiovascular Division, The British Heart Foundation Centre of Excellence, King's College London, London, United Kingdom (A.P., B.L., A.M.S., R.M.B.)
| | - Rene M Botnar
- Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom (A.P., B.L., S.L., R.M.B.) Cardiovascular Division, The British Heart Foundation Centre of Excellence, King's College London, London, United Kingdom (A.P., B.L., A.M.S., R.M.B.)
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Dorsey SM, McGarvey JR, Wang H, Nikou A, Arama L, Koomalsingh KJ, Kondo N, Gorman JH, Pilla JJ, Gorman RC, Wenk JF, Burdick JA. MRI evaluation of injectable hyaluronic acid-based hydrogel therapy to limit ventricular remodeling after myocardial infarction. Biomaterials 2015; 69:65-75. [PMID: 26280951 DOI: 10.1016/j.biomaterials.2015.08.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 08/03/2015] [Accepted: 08/05/2015] [Indexed: 11/19/2022]
Abstract
Injectable biomaterials are an attractive therapy to attenuate left ventricular (LV) remodeling after myocardial infarction (MI). Although studies have shown that injectable hydrogels improve cardiac structure and function in vivo, temporal changes in infarct material properties after treatment have not been assessed. Emerging imaging and modeling techniques now allow for serial, non-invasive estimation of infarct material properties. Specifically, cine magnetic resonance imaging (MRI) assesses global LV structure and function, late-gadolinium enhancement (LGE) MRI enables visualization of infarcted tissue to quantify infarct expansion, and spatial modulation of magnetization (SPAMM) tagging provides passive wall motion assessment as a measure of tissue strain, which can all be used to evaluate infarct properties when combined with finite element (FE) models. In this work, we investigated the temporal effects of degradable hyaluronic acid (HA) hydrogels on global LV remodeling, infarct thinning and expansion, and infarct stiffness in a porcine infarct model for 12 weeks post-MI using MRI and FE modeling. Hydrogel treatment led to decreased LV volumes, improved ejection fraction, and increased wall thickness when compared to controls. FE model simulations demonstrated that hydrogel therapy increased infarct stiffness for 12 weeks post-MI. Thus, evaluation of myocardial tissue properties through MRI and FE modeling provides insight into the influence of injectable hydrogel therapies on myocardial structure and function post-MI.
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Affiliation(s)
- Shauna M Dorsey
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jeremy R McGarvey
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hua Wang
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506, USA
| | - Amir Nikou
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506, USA
| | - Leron Arama
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kevin J Koomalsingh
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Norihiro Kondo
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - James J Pilla
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan F Wenk
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY 40506, USA; Department of Surgery, University of Kentucky, Lexington, KY 40506, USA
| | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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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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21
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McGarvey JR, Kondo N, Witschey WRT, Takebe M, Aoki C, Burdick JA, Spinale FG, Gorman JH, Pilla JJ, Gorman RC. Injectable microsphere gel progressively improves global ventricular function, regional contractile strain, and mitral regurgitation after myocardial infarction. Ann Thorac Surg 2015; 99:597-603. [PMID: 25524397 PMCID: PMC4314332 DOI: 10.1016/j.athoracsur.2014.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/05/2014] [Accepted: 09/09/2014] [Indexed: 11/20/2022]
Abstract
BACKGROUND There is continued need for therapies which reverse or abate the remodeling process after myocardial infarction (MI). In this study, we evaluate the longitudinal effects of calcium hydroxyapatite microsphere gel on regional strain, global ventricular function, and mitral regurgitation (MR) in a porcine MI model. METHODS Twenty-five Yorkshire swine were enrolled. Five were dedicated weight-matched controls. Twenty underwent posterolateral infarction by direct ligation of the circumflex artery and its branches. Infarcted animals were randomly divided into the following 4 groups: 1-week treatment; 1-week control; 4-week treatment; and 4-week control. After infarction, animals received either twenty 150 μL calcium hydroxyapatite gel or saline injections within the infarct. At their respective time points, echocardiograms, cardiac magnetic resonance imaging, and tissue were collected for evaluation of MR, regional and global left ventricular function, wall thickness, and collagen content. RESULTS Global and regional left ventricular functions were depressed in all infarcted subjects at 1 week compared with healthy controls. By 4-weeks post-infarction, global function had significantly improved in the calcium hydroxyapatite group compared with infarcted controls (ejection fraction 0.485 ± 0.019 vs 0.38 ± 0.017, p < 0.01). Similarly, regional borderzone radial contractile strain (16.3% ± 1.5% vs 11.2% ± 1.5%, p = 0.04), MR grade (0.4 ± 0.2 vs 1.2 ± 0.2, p = 0.04), and infarct thickness (7.8 ± 0.5 mm vs 4.5 ± 0.2 mm, p < 0.01) were improved at this time point in the treatment group compared with infarct controls. CONCLUSIONS Calcium hydroxyapatite injection after MI progressively improves global left ventricular function, borderzone function, and mitral regurgitation. Using novel biomaterials to augment infarct material properties is a viable alternative in the current management of heart failure.
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Affiliation(s)
- Jeremy R McGarvey
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Norihiro Kondo
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Walter R T Witschey
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Manabu Takebe
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Chikashi Aoki
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Francis G Spinale
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, South Carolina
| | - Joseph H Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - James J Pilla
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Robert C Gorman
- Gorman Cardiovascular Research Group, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
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22
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Veress AI, Fung GSK, Lee TS, Tsui BMW, Kicska GA, Paul Segars W, Gullberg GT. The direct incorporation of perfusion defect information to define ischemia and infarction in a finite element model of the left ventricle. J Biomech Eng 2014; 137:051004. [PMID: 25367177 DOI: 10.1115/1.4028989] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Indexed: 11/08/2022]
Abstract
This paper describes the process in which complex lesion geometries (specified by computer generated perfusion defects) are incorporated in the description of nonlinear finite element (FE) mechanical models used for specifying the motion of the left ventricle (LV) in the 4D extended cardiac torso (XCAT) phantom to simulate gated cardiac image data. An image interrogation process was developed to define the elements in the LV mesh as ischemic or infarcted based upon the values of sampled intensity levels of the perfusion maps. The intensity values were determined for each of the interior integration points of every element of the FE mesh. The average element intensity levels were then determined. The elements with average intensity values below a user-controlled threshold were defined as ischemic or infarcted depending upon the model being defined. For the infarction model cases, the thresholding and interrogation process were repeated in order to define a border zone (BZ) surrounding the infarction. This methodology was evaluated using perfusion maps created by the perfusion cardiac-torso (PCAT) phantom an extension of the 4D XCAT phantom. The PCAT was used to create 3D perfusion maps representing 90% occlusions at four locations (left anterior descending (LAD) segments 6 and 9, left circumflex (LCX) segment 11, right coronary artery (RCA) segment 1) in the coronary tree. The volumes and shapes of the defects defined in the FE mechanical models were compared with perfusion maps produced by the PCAT. The models were incorporated into the XCAT phantom. The ischemia models had reduced stroke volume (SV) by 18-59 ml. and ejection fraction (EF) values by 14-50% points compared to the normal models. The infarction models, had less reductions in SV and EF, 17-54 ml. and 14-45% points, respectively. The volumes of the ischemic/infarcted regions of the models were nearly identical to those volumes obtained from the perfusion images and were highly correlated (R² = 0.99).
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23
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Pahlm US, Ubachs JFA, Heiberg E, Engblom H, Erlinge D, Götberg M, Arheden H. Regional wall function before and after acute myocardial infarction; an experimental study in pigs. BMC Cardiovasc Disord 2014; 14:118. [PMID: 25218585 PMCID: PMC4169797 DOI: 10.1186/1471-2261-14-118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 09/09/2014] [Indexed: 11/29/2022] Open
Abstract
Background Left ventricular function is altered during and after AMI. Regional function can be determined by cardiac magnetic resonance (CMR) wall thickening, and velocity encoded (VE) strain analysis. The aims of this study were to investigate how regional myocardial wall function, assessed by CMR VE-strain and regional wall thickening, changes after acute myocardial infarction, and to determine if we could differentiate between ischemic, adjacent and remote segments of the left ventricle. Methods Ten pigs underwent baseline CMR study for assessment of wall thickening and VE-strain. Ischemia was then induced for 40-minutes by intracoronary balloon inflation in the left anterior descending coronary artery. During occlusion, 99mTc tetrofosmin was administered intravenously and myocardial perfusion SPECT (MPS) was performed for determination of the ischemic area, followed by a second CMR study. Based on ischemia seen on MPS, the 17 AHA segments of the left ventricle was divided into 3 different categories (ischemic, adjacent and remote). Regional wall function measured by wall thickening and VE-strain analysis was determined before and after ischemia. Results Mean wall thickening decreased significantly in the ischemic (from 2.7 mm to 0.65 mm, p < 0.001) and adjacent segments (from 2.4 to 1.5 mm p < 0.001). In remote segments, wall thickening increased significantly (from 2.4 mm to 2.8 mm, p < 0.01). In ischemic and adjacent segments, both radial and longitudinal strain was significantly decreased after ischemia (p < 0.001). In remote segments there was a significant increase in radial strain (p = 0.002) while there was no difference in longitudinal strain (p = 0.69). ROC analysis was performed to determine thresholds distinguishing between the different regions. Sensitivity for determining ischemic segments ranged from 70-80%, and specificity from 72%-77%. There was a 9% increase in left ventricular mass after ischemia. Conclusion Differentiation thresholds for wall thickening and VE-strain could be established to distinguish between ischemic, adjacent and remote segments but will, have limited applicability due to low sensitivity and specificity. There is a slight increase in radial strain in remote segments after ischemia. Edema was present mainly in the ischemic region but also in the combined adjacent and remote segments.
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Affiliation(s)
| | | | | | | | | | | | - Håkan Arheden
- Department of Clinical Physiology, Clinical Sciences, Lund University Hospital, SE-22185 Lund, Sweden.
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24
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Meßner NM, Zöllner FG, Kalayciyan R, Schad LR. Pre-clinical functional Magnetic Resonance Imaging Part II: The heart. Z Med Phys 2014; 24:307-22. [PMID: 25023418 DOI: 10.1016/j.zemedi.2014.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/09/2014] [Accepted: 06/17/2014] [Indexed: 12/21/2022]
Abstract
One third of all deaths worldwide in 2008 were caused by cardiovascular diseases (CVD), and the incidence of CVD related deaths rises ever more. Thus, improved imaging techniques and modalities are needed for the evaluation of cardiac morphology and function. Cardiac magnetic resonance imaging (CMRI) is a minimally invasive technique that is increasingly important due to its high spatial and temporal resolution, its high soft tissue contrast and its ability of functional and quantitative imaging. It is widely accepted as the gold standard of cardiac functional analysis. In the short period of small animal MRI, remarkable progress has been achieved concerning new, fast imaging schemes as well as purpose-built equipment. Dedicated small animal scanners allow for tapping the full potential of recently developed animal models of cardiac disease. In this paper, we review state-of-the-art cardiac magnetic resonance imaging techniques and applications in small animals at ultra-high fields (UHF).
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Affiliation(s)
- Nadja M Meßner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Raffi Kalayciyan
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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25
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Massilamany C, Khalilzad-Sharghi V, Gangaplara A, Steffen D, Othman SF, Reddy J. Noninvasive assessment of cardiac abnormalities in experimental autoimmune myocarditis by magnetic resonance microscopy imaging in the mouse. J Vis Exp 2014:e51654. [PMID: 24998332 DOI: 10.3791/51654] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Myocarditis is an inflammation of the myocardium, but only -10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-α 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-α 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.
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Affiliation(s)
| | | | - Arunakumar Gangaplara
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln
| | - David Steffen
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln
| | - Shadi F Othman
- Department of Biological Systems Engineering, University of Nebraska-Lincoln;
| | - Jay Reddy
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln;
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26
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Experimental and computational investigation of altered mechanical properties in myocardium after hydrogel injection. Ann Biomed Eng 2013; 42:1546-56. [PMID: 24271262 DOI: 10.1007/s10439-013-0937-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 11/08/2013] [Indexed: 10/26/2022]
Abstract
The material properties of myocardium are an important determinant of global left ventricular function. Myocardial infarction results in a series of maladaptive geometric alterations which lead to increased stress and risk of heart failure. In vivo studies have demonstrated that material injection can mitigate these changes. More importantly, the material properties of these injectates can be tuned to minimize wall thinning and ventricular dilation. The current investigation combines experimental data and finite element modeling to correlate how injectate mechanics and volume influence myocardial wall stress. Experimentally, mechanics were characterized with biaxial testing and injected hydrogel volumes were measured with magnetic resonance imaging. Injection of hyaluronic acid hydrogel increased the stiffness of the myocardium/hydrogel composite region in an anisotropic manner, significantly increasing the modulus in the longitudinal direction compared to control myocardium. Increased stiffness, in combination with increased volume from hydrogel injection, reduced the global average fiber stress by ~14% and the transmural average by ~26% in the simulations. Additionally, stiffening in an anisotropic manner enhanced the influence of hydrogel treatment in decreasing stress. Overall, this work provides insight on how injectable biomaterials can be used to attenuate wall stress and provides tools to further optimize material properties for therapeutic applications.
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27
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Kremer F, Dresselaers T, Heyde B, Ferferieva V, Caluwé E, Choi HF, Claus P, Oosterlinck W, Janssens S, Himmelreich U, D'hooge J. 2-D strain assessment in the mouse through spatial compounding of myocardial velocity data: in vivo feasibility. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1848-1860. [PMID: 23830981 DOI: 10.1016/j.ultrasmedbio.2013.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/20/2013] [Accepted: 04/04/2013] [Indexed: 06/02/2023]
Abstract
Ultrasound assessment of myocardial strain can provide valuable information on regional cardiac function. However, Doppler-based methods often used in practice for strain estimation suffer from angle dependency. In this study, a partial solution to that fundamental limitation is presented. We have previously reported using simulated data sets that spatial compounding of axial velocities obtained at three steering angles can theoretically outperform 2-D speckle tracking for 2-D strain estimation in the mouse heart. In this study, the feasibility of the method was analyzed in vivo using spatial compounding of Doppler velocities on six mice with myocardial infarction and five controls, and results were compared with those of tagged microscopic magnetic resonance imaging (μMRI). Circumferential estimates quantified by means of both ultrasound and μMRI could detect regional dysfunction. Between echocardiography and μMRI, a good regression coefficient was obtained for circumferential strain estimates (r = 0.69), whereas radial strain estimates correlated only moderately (r = 0.37). A second echocardiography was performed after μMRI to test the reproducibility of the compounding method. This yielded a higher correlation coefficient for the circumferential component than for the radial component (r = 0.74 circumferentially, r = 0.49 radially).
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Affiliation(s)
- Florence Kremer
- Division of Cardiovascular Imaging and Dynamics, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
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28
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Akki A, Gupta A, Weiss RG. Magnetic resonance imaging and spectroscopy of the murine cardiovascular system. Am J Physiol Heart Circ Physiol 2013; 304:H633-48. [PMID: 23292717 DOI: 10.1152/ajpheart.00771.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Magnetic resonance imaging (MRI) has emerged as a powerful and reliable tool to noninvasively study the cardiovascular system in clinical practice. Because transgenic mouse models have assumed a critical role in cardiovascular research, technological advances in MRI have been extended to mice over the last decade. These have provided critical insights into cardiac and vascular morphology, function, and physiology/pathophysiology in many murine models of heart disease. Furthermore, magnetic resonance spectroscopy (MRS) has allowed the nondestructive study of myocardial metabolism in both isolated hearts and in intact mice. This article reviews the current techniques and important pathophysiological insights from the application of MRI/MRS technology to murine models of cardiovascular disease.
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Affiliation(s)
- Ashwin Akki
- Division of Cardiology, Department of Medicine, and Division of Magnetic Resonance Research, Department of Radiology, The Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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29
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Naresh NK, Xu Y, Klibanov AL, Vandsburger MH, Meyer CH, Leor J, Kramer CM, French BA, Epstein FH. Monocyte and/or macrophage infiltration of heart after myocardial infarction: MR imaging by using T1-shortening liposomes. Radiology 2012; 264:428-35. [PMID: 22723500 DOI: 10.1148/radiol.12111863] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE To test the hypothesis that magnetic resonance (MR) imaging R1 (R1 = 1/T1) mapping after selectively labeling monocytes with a T1-shortening contrast agent in vivo would enable the quantitative measurement of their spatiotemporal kinetics in the setting of infarct healing. MATERIALS AND METHODS All procedures were performed in mice and were approved by the institutional committee on animal research. One hundred microliters of dual-labeled liposomes (DLLs) containing gadolinium (Gd)-diethylenetriaminepentaacetic acid (DTPA)-bis(stearylamide) and DiI dye were used to label monocytes 2 days before myocardial infarction (MI). MI was induced by occlusion of the left anterior descending coronary artery for 1 hour, followed by reperfusion. MR imaging R1 mapping of mouse hearts was performed at baseline on day -3, on day 0 before MI, and on days 1, 4, and 7 after MI. Mice without labeling were used as controls. ΔR1 was calculated as the difference in R1 between mice with labeling and those without labeling. CD68 immunohistochemistry and DiI fluorescence microscopy were used to confirm that labeled monocytes and/or macrophages infiltrated the postinfarct myocardium. Statistical analysis was performed by using two-way analysis of variance and the unpaired two-sample t test. RESULTS Infarct zone ΔR1 was slightly but nonsignificantly increased on day 1, maximum on day 4 (P < .05 vs all other days), and started to decrease by day 7 (P < .05 vs days -3, 0, and 1) after MI, closely reflecting the time course of monocyte and/or macrophage infiltration of the infarcted myocardium shown by prior histologic studies. Histologic results confirmed the presence and location of DLL-labeled monocytes and/or macrophages in the infarct zone on day 4 after MI. CONCLUSION R1 mapping after labeling monocytes with T1-shortening DLLs enables the measurement of post-MI monocyte and/or macrophage spatiotemporal kinetics.
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Affiliation(s)
- Nivedita K Naresh
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
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30
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Constantinides C, Angeli S, Kossivas F, Ktorides P. Underestimation of Murine Cardiac Hemodynamics Using Invasive Catheters: Errors, Limitations, and Remedies. Cardiovasc Eng Technol 2012. [DOI: 10.1007/s13239-012-0084-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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31
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Leonard BL, Smaill BH, LeGrice IJ. Structural remodeling and mechanical function in heart failure. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2012; 18:50-67. [PMID: 22258722 DOI: 10.1017/s1431927611012438] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The cardiac extracellular matrix (ECM) is the three-dimensional scaffold that defines the geometry and muscular architecture of the cardiac chambers and transmits forces produced during the cardiac cycle throughout the heart wall. The cardiac ECM is an active system that responds to the stresses to which it is exposed and in the normal heart is adapted to facilitate efficient mechanical function. There are marked differences in the short- and medium-term changes in ventricular geometry and cardiac ECM that occur as a result of volume overload, hypertension, and ischemic cardiomyopathy. Despite this, there is a widespread view that a common remodeling "phenotype" governs the final progression to end-stage heart failure in different forms of heart disease. In this review article, we make the case that this interpretation is not consistent with the clinical and experimental data on the topic. We argue that there is a need for new theoretical and experimental models that will enable stresses acting on the ECM and resultant deformations to be estimated more accurately and provide better spatial resolution of local signaling mechanisms that are activated as a result. These developments are necessary to link the effects of structural remodeling with altered cardiac mechanical function.
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Affiliation(s)
- Bridget Louise Leonard
- Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland 1023, New Zealand.
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32
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Dall'Armellina E, Jung BA, Lygate CA, Neubauer S, Markl M, Schneider JE. Improved method for quantification of regional cardiac function in mice using phase-contrast MRI. Magn Reson Med 2012; 67:541-51. [PMID: 21674616 PMCID: PMC3378699 DOI: 10.1002/mrm.23022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 04/04/2011] [Accepted: 05/05/2011] [Indexed: 11/08/2022]
Abstract
Phase-contrast magnetic resonance imaging is a technique that allows for characterization of regional cardiac function and for measuring transmural myocardial velocities in human hearts with high temporal and spatial resolution. The application of this technique (also known as tissue phase mapping) to murine hearts has been very limited so far. The aim of our study was to implement and to optimize tissue phase mapping for a comprehensive assessment of murine transmural wall motion. Baseline values for regional motion patterns in mouse hearts, based on the clinically used American Heart Association's 17-segment model, were established, and a detailed motion analysis of mouse heart for the entire cardiac cycle (including epicardial and endocardial motion patterns) is provided. Black-blood contrast was found to be essential to obtain reproducible velocity encoding. Tissue phase mapping of the mouse heart permits the detailed assessment of regional myocardial velocities. While a proof-of-principle application in a murine ischemia-reperfusion model was performed, future studies are warranted to assess its potential for the investigation of systolic and diastolic functions in genetically and surgically manipulated mouse models of human heart disease.
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Affiliation(s)
- Erica Dall'Armellina
- Department of Cardiovascular Medicine, University of OxfordOxford, United Kingdom
| | - Bernd A Jung
- Department of Radiology, Medical Physics, University Hospital FreiburgGermany
| | - Craig A Lygate
- Department of Cardiovascular Medicine, University of OxfordOxford, United Kingdom
| | - Stefan Neubauer
- Department of Cardiovascular Medicine, University of OxfordOxford, United Kingdom
| | - Michael Markl
- Department of Radiology, Medical Physics, University Hospital FreiburgGermany
| | - Jürgen E Schneider
- Department of Cardiovascular Medicine, University of OxfordOxford, United Kingdom
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Function of remote non-infarcted myocardium after STEMI: analysis with cardiovascular magnetic resonance. Int J Cardiovasc Imaging 2012; 28:2057-64. [DOI: 10.1007/s10554-012-0014-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 01/02/2012] [Indexed: 11/25/2022]
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Abstract
High-resolution magnetic resonance cine imaging (cine-MRI) allows for a non-invasive assessment of ventricular function and mass in normal mice and in genetically and surgically modified mouse models of cardiac disease. The assessment of myocardial mass and function by cine-MRI does not rely on geometric assumptions, as the hearts are covered from the base to the apex, typically by a stack of two-dimensional images. The MR data acquisition is then followed by image segmentation of specific cine frames in each slice to obtain geometric and functional parameters, such as end-diastolic volume (EDV), end-systolic volume (ESV) or ejection fraction (EF). This technique has been well established in clinical routine application and it is now also becoming the reference method in experimental cardiovascular MRI. The cine images are typically acquired in short- and long-axis orientations of the heart to facilitate an accurate assessment of cardiac functional parameters. These views can be difficult to identify, particularly in animals with diseased hearts. Furthermore, data analysis can be the source of a systematic error, mainly for myocardial mass measurement. We have established protocols that allow for a quick and reproducible way of obtaining the relevant cardiac views for cine-MRI, and for accurate image analysis.
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Botnar RM, Makowski MR. Cardiovascular magnetic resonance imaging in small animals. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 105:227-61. [PMID: 22137434 DOI: 10.1016/b978-0-12-394596-9.00008-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Noninvasive imaging studies involving small animals are becoming increasingly important in preclinical pharmacological, genetic, and biomedical cardiovascular research. Especially small animal magnetic resonance imaging (MRI) using high field and clinical MRI systems has gained significant importance in recent years. Compared to other imaging modalities, like computer tomography, MRI can provide an excellent soft tissue contrast, which enables the characterization of different kinds of tissues without the use of contrast agents. In addition, imaging can be performed with high spatial and temporal resolution. Small animal MRI cannot only provide anatomical information about the beating murine heart; it can also provide functional and molecular information, which makes it a unique imaging modality. Compared to clinical MRI examinations in humans, small animal MRI is associated with additional challenges. These included a smaller size of all cardiovascular structures and a up to ten times higher heart rate. Dedicated small animal monitoring devices make a reliable cardiac triggering and respiratory gating feasible. MRI in combination with molecular probes enables the noninvasive imaging of biological processes at a molecular level. Different kinds of iron oxide or gadolinium-based contrast agents can be used for this purpose. Compared to other molecular imaging modalities, like single photon emission computed tomography (SPECT) and positron emission tomography (PET), MRI can also provide imaging with high spatial resolution, which is of high importance for the assessment of the cardiovascular system. The sensitivity for detection of MRI contrast agents is however lower compared to sensitivity of radiation associated techniques like PET and SPECT. This chapter is divided into the following sections: (1) "Introduction," (2) "Principals of Magnetic Resonance Imaging," (3) "MRI Systems for Preclinical Imaging and Experimental Setup," and (4) "Cardiovascular Magnetic Resonance Imaging."
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Affiliation(s)
- René M Botnar
- Division of Imaging Sciences, King's College London, London, United Kingdom
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Zhong X, Gibberman LB, Spottiswoode BS, Gilliam AD, Meyer CH, French BA, Epstein FH. Comprehensive cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE. J Cardiovasc Magn Reson 2011; 13:83. [PMID: 22208954 PMCID: PMC3278394 DOI: 10.1186/1532-429x-13-83] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 12/30/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. METHODS A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. RESULTS Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 ± 0.17, -0.13 ± 0.03, and -0.18 ± 0.14 for E(rr), E(cc), and E(ll), respectively. Peak end-systolic values for the shear strains were 0.00 ± 0.08, 0.04 ± 0.12, and 0.03 ± 0.07 for E(rc), E(rl), and E(cl), respectively. The peak end-systolic normalized torsion was 5.6 ± 0.9°. CONCLUSIONS Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.
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Affiliation(s)
| | | | - Bruce S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | | | - Craig H Meyer
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Brent A French
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Frederick H Epstein
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
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Tous E, Ifkovits JL, Koomalsingh KJ, Shuto T, Soeda T, Kondo N, Gorman JH, Gorman RC, Burdick JA. Influence of injectable hyaluronic acid hydrogel degradation behavior on infarction-induced ventricular remodeling. Biomacromolecules 2011; 12:4127-35. [PMID: 21967486 PMCID: PMC3246217 DOI: 10.1021/bm201198x] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Increased myocardial wall stress after myocardial infarction (MI) initiates the process of adverse left ventricular (LV) remodeling that is manifest as progressive LV dilatation, loss of global contractile function, and symptomatic heart failure, and recent work has shown that reduction in wall stress through injectable bulking agents attenuates these outcomes. In this study, hyaluronic acid (HA) was functionalized to exhibit controlled and tunable mechanics and degradation once cross-linked, in an attempt to assess the temporal dependency of mechanical stabilization in LV remodeling. Specifically, two hydrolytically degrading (low and high HeMA-HA, degrading in ~3 and 10 weeks, respectively) and two stable (low and high MeHA, little mass loss even after 8 weeks) hydrogels with similar initial mechanics (low: ~7 kPa; high: ~35-40 kPa) were evaluated in an ovine model of MI. Generally, the more stable hydrogels maintained myocardial wall thickness in the apical and basilar regions more efficiently (low MeHA: apical: 6.5 mm, basilar: 7 mm, high MeHA: apical: 7.0 mm basilar: 7.2 mm) than the hydrolytically degrading hydrogels (low HeMA-HA: apical: 3.5 mm, basilar: 6.0 mm, high HeMA-HA: apical: 4.1 mm, basilar: 6.1 mm); however, all hydrogel groups were improved compared to infarct controls (IC) (apical: 2.2 mm, basilar: 4.6 mm). Histological analysis at 8 weeks demonstrated that although both degradable hydrogels resulted in increased inflammation, all treatments resulted in increased vessel formation compared to IC. Further evaluation revealed that while high HeMA-HA and high MeHA maintained reduced LV volumes at 2 weeks, high MeHA was more effective at 8 weeks, implying that longer wall stabilization is needed for volume maintenance. All hydrogel groups resulted in better cardiac output (CO) values than IC.
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Affiliation(s)
- Elena Tous
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jamie L. Ifkovits
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Kevin J. Koomalsingh
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Takashi Shuto
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Toru Soeda
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Norihiro Kondo
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Joseph H. Gorman
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Robert C. Gorman
- Gorman Cardiovascular Research Group, University of Pennsylvania, Glenolden, PA, 19036, USA
| | - Jason A. Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
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38
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Price AN, Cheung KK, Lim SY, Yellon DM, Hausenloy DJ, Lythgoe MF. Rapid assessment of myocardial infarct size in rodents using multi-slice inversion recovery late gadolinium enhancement CMR at 9.4T. J Cardiovasc Magn Reson 2011; 13:44. [PMID: 21892953 PMCID: PMC3182945 DOI: 10.1186/1532-429x-13-44] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 09/05/2011] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Myocardial infarction (MI) can be readily assessed using late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR). Inversion recovery (IR) sequences provide the highest contrast between enhanced infarct areas and healthy myocardium. Applying such methods to small animals is challenging due to rapid respiratory and cardiac rates relative to T1 relaxation. METHODS Here we present a fast and robust protocol for assessing LGE in small animals using a multi-slice IR gradient echo sequence for efficient assessment of LGE. An additional Look-Locker sequence was used to assess the optimum inversion point on an individual basis and to determine most appropriate gating points for both rat and mouse. The technique was applied to two preclinical scenarios: i) an acute (2 hour) reperfused model of MI in rats and ii) mice 2 days following non-reperfused MI. RESULTS LGE images from all animals revealed clear areas of enhancement allowing for easy volume segmentation. Typical inversion times required to null healthy myocardium in rats were between 300-450 ms equivalent to 2-3 R-waves and ~330 ms in mice, typically 3 R-waves following inversion. Data from rats was also validated against triphenyltetrazolium chloride staining and revealed close agreement for infarct size. CONCLUSION The LGE protocol presented provides a reliable method for acquiring images of high contrast and quality without excessive scan times, enabling higher throughput in experimental studies requiring reliable assessment of MI.
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Affiliation(s)
- Anthony N Price
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
| | - King K Cheung
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
| | - Shiang Y Lim
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Derek J Hausenloy
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, London, UK
| | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
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39
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Franzosi M, Guerrini U, Castiglioni L, Sironi L, Nobili E, Tremoli E, Caiani EG. Feasibility of quantitative analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating. Comput Biol Med 2011; 41:829-37. [PMID: 21783184 DOI: 10.1016/j.compbiomed.2011.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 02/04/2011] [Accepted: 06/30/2011] [Indexed: 11/30/2022]
Abstract
We aimed testing feasibility of identification of regional left ventricular (LV) endocardial motion abnormalities in mice undergoing coronary ligation (MI), using cine magnetic resonance with retrospective gating and computation of regional fractional area change (RFAC), by comparison with histological "gold standard" evaluation. ROC analysis determined the optimal RFAC cut-off values for detecting regional ischemic injury. This approach was tested on 18 MI and 10 sham mice. Automated regional LV motion interpretation and bull's eye display allowed non-invasive localization of the induced infarction. Possible applications to future studies assessing the effectiveness of pharmacological treatments or regenerative medicine are expected.
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Affiliation(s)
- Matteo Franzosi
- Dipartimento di Scienze Farmacologiche, Università degli Studi di Milano, Milan, Italy
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40
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Li Y, Garson CD, Xu Y, Helm PA, Hossack JA, French BA. Serial ultrasound evaluation of intramyocardial strain after reperfused myocardial infarction reveals that remote zone dyssynchrony develops in concert with left ventricular remodeling. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:1073-1086. [PMID: 21640480 PMCID: PMC3119373 DOI: 10.1016/j.ultrasmedbio.2011.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 03/14/2011] [Accepted: 04/04/2011] [Indexed: 05/30/2023]
Abstract
This study noninvasively evaluated the development of left ventricular (LV) dyssynchrony following reperfused myocardial infarction (MI) in mice using an ultrasonic speckle-tracking method. Eight C57BL/6J mice were assessed by high-resolution echocardiography at baseline and at eight time-points following MI. Images were acquired at 1mm elevational intervals encompassing the entire LV to determine chamber volumes and radial strain. Receiver-operating characteristic (ROC) analysis of regional radial strain was used to segment the three-dimensional (3-D) LV into infarct, adjacent and remote zones. This in vivo segmentation was correlated to histologic infarct size (R = 0.89, p < 0.01) in a short-axis, slice-by-slice comparison. The onset of dyssynchrony during LV remodeling was assessed by standard deviation of time to peak radial strain in the infarct, adjacent and remote zones. It was discovered that the form of LV dyssynchrony that develops in the remote zone late after MI does so in concert with the progression of LV remodeling (R = 0.70, p < 0.05).
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Affiliation(s)
- Yinbo Li
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Christopher D. Garson
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Yaqin Xu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | | | - John A. Hossack
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Brent A. French
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
- Radiology, University of Virginia, Charlottesville, VA, USA
- Medicine, University of Virginia, Charlottesville, VA, USA
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41
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Injectable acellular hydrogels for cardiac repair. J Cardiovasc Transl Res 2011; 4:528-42. [PMID: 21710332 DOI: 10.1007/s12265-011-9291-1] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 06/10/2011] [Indexed: 12/24/2022]
Abstract
Injectable hydrogels are being developed as potential translatable materials to influence the cascade of events that occur after myocardial infarction. These hydrogels, consisting of both synthetic and natural materials, form through numerous chemical crosslinking and assembly mechanisms and can be used as bulking agents or for the delivery of biological molecules. Specifically, a range of materials are being applied that alter the resulting mechanical and biological signals after infarction and have shown success in reducing stresses in the myocardium and limiting the resulting adverse left ventricular (LV) remodeling. Additionally, the delivery of molecules from injectable hydrogels can influence cellular processes such as apoptosis and angiogenesis in cardiac tissue or can be used to recruit stem cells for repair. There is still considerable work to be performed to elucidate the mechanisms of these injectable hydrogels and to optimize their various properties (e.g., mechanics and degradation profiles). Furthermore, although the experimental findings completed to date in small animals are promising, future work needs to focus on the use of large animal models in clinically relevant scenarios. Interest in this therapeutic approach is high due to the potential for developing percutaneous therapies to limit LV remodeling and to prevent the onset of congestive heart failure that occurs with loss of global LV function. This review focuses on recent efforts to develop these injectable and acellular hydrogels to aid in cardiac repair.
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42
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Schneider JE, Lanz T, Barnes H, Stork LA, Bohl S, Lygate CA, Ordidge RJ, Neubauer S. Accelerated cardiac magnetic resonance imaging in the mouse using an eight-channel array at 9.4 Tesla. Magn Reson Med 2011; 65:60-70. [PMID: 20740650 PMCID: PMC3021721 DOI: 10.1002/mrm.22605] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
MRI has become an important tool to noninvasively assess global and regional cardiac function, infarct size, or myocardial blood flow in surgically or genetically modified mouse models of human heart disease. Constraints on scan time due to sensitivity to general anesthesia in hemodynamically compromised mice frequently limit the number of parameters available in one imaging session. Parallel imaging techniques to reduce acquisition times require coil arrays, which are technically challenging to design at ultrahigh magnetic field strengths. This work validates the use of an eight-channel volume phased-array coil for cardiac MRI in mice at 9.4 T. Two- and three-dimensional sequences were combined with parallel imaging techniques and used to quantify global cardiac function, T(1)-relaxation times and infarct sizes. Furthermore, the rapid acquisition of functional cine-data allowed for the first time in mice measurement of left-ventricular peak filling and ejection rates under intravenous infusion of dobutamine. The results demonstrate that a threefold accelerated data acquisition is generally feasible without compromising the accuracy of the results. This strategy may eventually pave the way for routine, multiparametric phenotyping of mouse hearts in vivo within one imaging session of tolerable duration.
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Affiliation(s)
- Jürgen E Schneider
- British Heart Foundation Experimental MR Unit (BMRU), Department of Cardiovascular Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom.
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Veress AI, Segars WP, Tsui BMW, Gullberg GT. Incorporation of a left ventricle finite element model defining infarction into the XCAT imaging phantom. IEEE TRANSACTIONS ON MEDICAL IMAGING 2011; 30:915-927. [PMID: 21041157 PMCID: PMC3097415 DOI: 10.1109/tmi.2010.2089801] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The 4D extended cardiac-torso (XCAT) phantom was developed to provide a realistic and flexible model of the human anatomy and cardiac and respiratory motions for use in medical imaging research. A prior limitation to the phantom was that it did not accurately simulate altered functions of the heart that result from cardiac pathologies such as coronary artery disease (CAD). We overcame this limitation in a previous study by combining the phantom with a finite-element (FE) mechanical model of the left ventricle (LV) capable of more realistically simulating regional defects caused by ischemia. In the present work, we extend this model giving it the ability to accurately simulate motion abnormalities caused by myocardial infarction (MI), a far more complex situation in terms of altered mechanics compared with the modeling of acute ischemia. The FE model geometry is based on high resolution CT images of a normal male subject. An anterior region was defined as infarcted and the material properties and fiber distribution were altered, according to the bio-physiological properties of two types of infarction, i.e., fibrous and remodeled infarction (30% thinner wall than fibrous case). Compared with the original, surface-based 4D beating heart model of the XCAT, where regional abnormalities are modeled by simply scaling down the motion in those regions, the FE model was found to provide a more accurate representation of the abnormal motion of the LV due to the effects of fibrous infarction as well as depicting the motion of remodeled infarction. In particular, the FE models allow for the accurate depiction of dyskinetic motion. The average circumferential strain results were found to be consistent with measured dyskinetic experimental results. Combined with the 4D XCAT phantom, the FE model can be used to produce realistic multimodality sets of imaging data from a variety of patients in which the normal or abnormal cardiac function is accurately represented.
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Affiliation(s)
| | - W. Paul Segars
- Department of Radiology, Duke University, Durham, NC 27705 USA
| | | | - Grant T. Gullberg
- E. O. Lawrence Berkeley National Laboratory, Life Science Division, Berkeley, CA 94720 USA
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44
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Vandsburger MH, Epstein FH. Emerging MRI methods in translational cardiovascular research. J Cardiovasc Transl Res 2011; 4:477-92. [PMID: 21452060 DOI: 10.1007/s12265-011-9275-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 03/15/2011] [Indexed: 12/11/2022]
Abstract
Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside.
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Affiliation(s)
- Moriel H Vandsburger
- Department of Biological Regulation, Weizmann Institute of Science, 76100, Rehovot, Israel.
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45
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Chuang JS, Zemljic-Harpf A, Ross RS, Frank LR, McCulloch AD, Omens JH. Determination of three-dimensional ventricular strain distributions in gene-targeted mice using tagged MRI. Magn Reson Med 2011; 64:1281-8. [PMID: 20981782 DOI: 10.1002/mrm.22547] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A model-based method for calculating three-dimensional (3D) cardiac wall strain distributions in the mouse has been developed and tested in a genetically engineered mouse model of dilated cardiomyopathy. Data from MR tagging and harmonic phase (HARP) tracking were used to measure material point displacements, and 3D Lagrangian strains were calculated throughout the entire left ventricle (LV) with a deformable parametric model. A mouse model where cardiomyocytes are specifically made deficient in vinculin (VclKO) were compared to wild-type (WT) littermates. 3D strain analysis revealed differences in LV wall mechanics between WT and VclKO mice at 8 weeks of age when systolic function had just begun to decline. Most notably, end-systolic radial strain and torsional shear were reduced in VclKO hearts which contributed to regional mechanical dysfunction. This study demonstrates the feasibility of using MRI tagging methods to detect alterations in 3D myocardial strain distributions in genetically engineered mouse models of cardiovascular disease.
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Affiliation(s)
- Joyce S Chuang
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA
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46
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Li W, Yu X. Quantification of myocardial strain at early systole in mouse heart: restoration of undeformed tagging grid with single-point HARP. J Magn Reson Imaging 2011; 32:608-14. [PMID: 20815058 DOI: 10.1002/jmri.22256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop accurate strain and torsion quantification method for the assessment of myocardial contraction in mice by MRI tagging. MATERIALS AND METHODS Ventricular wall motion at baseline and during beta-adrenergic stimulation was assessed in mice using MRI tagging. Myocardial strain and torsion were quantified using finite element analysis method. A harmonic phase (HARP) based method was developed for the restoration of undeformed taglines for more accurate calculation of myocardial wall strain and torsion. RESULTS Myocardial deformation was observed at early systole (<20 msec after QRS) both at baseline and during beta-adrenergic stimulation. The HARP-based method allowed robust restoration of undeformed taglines that can be used as the reference in finite element analysis of the tagged images. Without such correction for myocardial deformation in the reference image, inaccuracy in strain quantification underestimated significant strain development at early systole in dobutamine-stimulated hearts. CONCLUSION The HARP-based method developed in the current study enabled automated restoration of undeformed taglines in mouse hearts, leading to more accurate calculation of myocardial wall strain and torsion during dobutamine stimulation.
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Affiliation(s)
- Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44122, USA
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47
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Qiao H, Zhang H, Yamanaka S, Patel VV, Petrenko NB, Huang B, Muenz LR, Ferrari VA, Boheler KR, Zhou R. Long-term improvement in postinfarct left ventricular global and regional contractile function is mediated by embryonic stem cell-derived cardiomyocytes. Circ Cardiovasc Imaging 2010; 4:33-41. [PMID: 21059858 DOI: 10.1161/circimaging.110.957431] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pluripotent stem cells represent one promising source for cellular cardiomyoplasty. In this study, we used cardiac magnetic resonance to examine the ability of highly enriched cardiomyocytes (CMs) derived from murine embryonic stem cells (ESC) to form grafts and improve contractile function of infarcted rat hearts. METHODS AND RESULTS Highly enriched ESC-CMs were obtained by inducing cardiac differentiation of ESCs stably expressing a cardiac-restricted puromycin resistance gene. At the time of transplantation, enriched ESC-CMs expressed cardiac-specific markers and markers of developing CMs, but only 6% of them were proliferating. A growth factor-containing vehicle solution or ESC-CMs (5 to 10 million) suspended in the same solution was injected into athymic rat hearts 1 week after myocardial infarction. Initial infarct size was measured by cardiac magnetic resonance 1 day after myocardial infarction. Compared with vehicle treatment, treatment with ESC-CMs improved global systolic function 1 and 2 months after injection and significantly increased contractile function in initially infarcted areas and border zones. Immunohistochemistry confirmed successful engraftment and the persistence of α-actinin-positive ESC-CMs that also expressed α-smooth muscle actin. Connexin-43-positive sites were observed between grafted ESC-CMs but only rarely between grafted and host CMs. No teratomas were observed in any of the animals. CONCLUSIONS Highly enriched and early-stage ESC-CMs were safe, formed stable grafts, and mediated a long-term recovery of global and regional myocardial contractile function after infarction.
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Affiliation(s)
- Hui Qiao
- Laboratories of Molecular Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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48
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Zhong J, Yu X. Strain and torsion quantification in mouse hearts under dobutamine stimulation using 2D multiphase MR DENSE. Magn Reson Med 2010; 64:1315-22. [PMID: 20740659 DOI: 10.1002/mrm.22530] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 11/08/2022]
Abstract
In this study, a 2D multiphase magnetic resonance displacement encoding with stimulated echoes (DENSE) imaging and analysis method was developed for direct quantification of Lagrangian strain in the mouse heart. Using the proposed method, <10 ms temporal resolution and 0.56 mm in-plane resolution were achieved. A validation study that compared strain calculation by displacement encoding with stimulated echoes and by magnetic resonance tagging showed high correlation between the two methods (R(2) > 0.80). Regional ventricular wall strain and twist were characterized in mouse hearts at baseline and under dobutamine stimulation. Dobutamine stimulation induced significant increase in radial and circumferential strains and torsion at peak systole. A rapid untwisting was also observed during early diastole. This work demonstrates the capability of characterizing cardiac functional response to dobutamine stimulation in the mouse heart using 2D multiphase magnetic resonance displacement encoding with stimulated echoes.
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Affiliation(s)
- Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
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Injectable hydrogel properties influence infarct expansion and extent of postinfarction left ventricular remodeling in an ovine model. Proc Natl Acad Sci U S A 2010; 107:11507-12. [PMID: 20534527 DOI: 10.1073/pnas.1004097107] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A recent trend has emerged that involves myocardial injection of biomaterials, containing cells or acellular, following myocardial infarction (MI) to influence the remodeling response through both biological and mechanical effects. Despite the number of different materials injected in these approaches, there has been little investigation into the importance of material properties on therapeutic outcomes. This work focuses on the investigation of injectable hyaluronic acid (MeHA) hydrogels that have tunable mechanics and gelation behavior. Specifically, two MeHA formulations that exhibit similar degradation and tissue distribution upon injection but have differential moduli (approximately 8 versus approximately 43 kPa) were injected into a clinically relevant ovine MI model to evaluate the associated salutary effect of intramyocardial hydrogel injection on the remodeling response based on hydrogel mechanics. Treatment with both hydrogels significantly increased the wall thickness in the apex and basilar infarct regions compared with the control infarct. However, only the higher-modulus (MeHA High) treatment group had a statistically smaller infarct area compared with the control infarct group. Moreover, reductions in normalized end-diastolic and end-systolic volumes were observed for the MeHA High group. This group also tended to have better functional outcomes (cardiac output and ejection fraction) than the low-modulus (MeHA Low) and control infarct groups. This study provides fundamental information that can be used in the rational design of therapeutic materials for treatment of MI.
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Delattre BMA, Braunersreuther V, Hyacinthe JN, Crowe LA, Mach F, Vallée JP. Myocardial infarction quantification with Manganese-Enhanced MRI (MEMRI) in mice using a 3T clinical scanner. NMR IN BIOMEDICINE 2010; 23:503-513. [PMID: 20175138 DOI: 10.1002/nbm.1489] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Manganese (Mn(2+)) was recognized early as an efficient intracellular MR contrast agent to assess cardiomyocyte viability. It had previously been used for the assessment of myocardial infarction in various animal models from pig to mouse. However, whether Manganese-Enhanced MRI (MEMRI) is also able to assess infarction in the acute phase of a coronary occlusion reperfusion model in mice has not yet been demonstrated. This model is of particular interest as it is closer to the situation encountered in the clinical setting. This study aimed to measure infarction volume taking TTC staining as a gold standard, as well as global and regional function before and after Mn(2+) injection using a clinical 3T scanner. The first step of this study was to perform a dose-response curve in order to optimize the injection protocol. Infarction volume measured with MEMRI was strongly correlated to TTC staining. Ejection fraction (EF) and percent wall thickening measurements allowed evaluation of global and regional function. While EF must be measured before Mn(2+) injection to avoid bias introduced by the reduction of contrast in cine images, percent wall thickening can be measured either before or after Mn(2+) injection and depicts accurately infarct related contraction deficit. This study is the first step for further longitudinal studies of cardiac disease in mice on a clinical 3T scanner, a widely available platform.
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