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Schmitt PR, Dwyer KD, Coulombe KLK. Current Applications of Polycaprolactone as a Scaffold Material for Heart Regeneration. ACS APPLIED BIO MATERIALS 2022; 5:2461-2480. [PMID: 35623101 DOI: 10.1021/acsabm.2c00174] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Despite numerous advances in treatments for cardiovascular disease, heart failure (HF) remains the leading cause of death worldwide. A significant factor contributing to the progression of cardiovascular diseases into HF is the loss of functioning cardiomyocytes. The recent growth in the field of cardiac tissue engineering has the potential to not only reduce the downstream effects of injured tissues on heart function and longevity but also re-engineer cardiac function through regeneration of contractile tissue. One leading strategy to accomplish this is via a cellularized patch that can be surgically implanted onto a diseased heart. A key area of this field is the use of tissue scaffolds to recapitulate the mechanical and structural environment of the native heart and thus promote engineered myocardium contractility and function. While the strong mechanical properties and anisotropic structural organization of the native heart can be largely attributed to a robust extracellular matrix, similar strength and organization has proven to be difficult to achieve in cultured tissues. Polycaprolactone (PCL) is an emerging contender to fill these gaps in fabricating scaffolds that mimic the mechanics and structure of the native heart. In the field of cardiovascular engineering, PCL has recently begun to be studied as a scaffold for regenerating the myocardium due to its facile fabrication, desirable mechanical, chemical, and biocompatible properties, and perhaps most importantly, biodegradability, which make it suitable for regenerating and re-engineering function to the heart after disease or injury. This review focuses on the application of PCL as a scaffold specifically in myocardium repair and regeneration and outlines current fabrication approaches, properties, and possibilities of PCL incorporation into engineered myocardium, as well as provides suggestions for future directions and a roadmap toward clinical translation of this technology.
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Affiliation(s)
- Phillip R Schmitt
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Kiera D Dwyer
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Kareen L K Coulombe
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, Rhode Island 02912, United States
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Zhang X, Qiu B, Wei Z, Yan F, Shi C, Su S, Liu X, Ji JX, Xie G. Three-dimensional self-gated cardiac MR imaging for the evaluation of myocardial infarction in mouse model on a 3T clinical MR system. PLoS One 2017; 12:e0189286. [PMID: 29216303 PMCID: PMC5720776 DOI: 10.1371/journal.pone.0189286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/23/2017] [Indexed: 12/25/2022] Open
Abstract
Purpose To develop and assess a three-dimensional (3D) self-gated technique for the evaluation of myocardial infarction (MI) in mouse model without the use of external electrocardiogram (ECG) trigger and respiratory motion sensor on a 3T clinical MR system. Methods A 3D T1-weighted GRE sequence with stack-of-stars sampling trajectories was developed and performed on six mice with MIs that were injected with a gadolinium-based contrast agent at a 3T clinical MR system. Respiratory and cardiac self-gating signals were derived from the Cartesian mapping of the k-space center along the partition encoding direction by bandpass filtering in image domain. The data were then realigned according to the predetermined self-gating signals for the following image reconstruction. In order to accelerate the data acquisition, image reconstruction was based on compressed sensing (CS) theory by exploiting temporal sparsity of the reconstructed images. In addition, images were also reconstructed from the same realigned data by conventional regridding method for demonstrating the advantageous of the proposed reconstruction method. Furthermore, the accuracy of detecting MI by the proposed method was assessed using histological analysis as the standard reference. Linear regression and Bland-Altman analysis were used to assess the agreement between the proposed method and the histological analysis. Results Compared to the conventional regridding method, the proposed CS method reconstructed images with much less streaking artifact, as well as a better contrast-to-noise ratio (CNR) between the blood and myocardium (4.1 ± 2.1 vs. 2.9 ± 1.1, p = 0.031). Linear regression and Bland-Altman analysis demonstrated that excellent correlation was obtained between infarct sizes derived from the proposed method and histology analysis. Conclusion A 3D T1-weighted self-gating technique for mouse cardiac imaging was developed, which has potential for accurately evaluating MIs in mice at 3T clinical MR system without the use of external ECG trigger and respiratory motion sensor.
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Affiliation(s)
- Xiaoyong Zhang
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, China
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Bensheng Qiu
- Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, China
- * E-mail: (GX); (BQ)
| | - Zijun Wei
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Fei Yan
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Caiyun Shi
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Shi Su
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xin Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Jim X. Ji
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Guoxi Xie
- The Sixth Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- * E-mail: (GX); (BQ)
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Evans E, Buonincontri G, Izquierdo D, Methner C, Hawkes RC, Ansorge RE, Krieg T, Carpenter TA, Sawiak SJ. Combining MRI with PET for partial volume correction improves image-derived input functions in mice. IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2015; 62:628-633. [PMID: 26213413 PMCID: PMC4510926 DOI: 10.1109/tns.2015.2433897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Accurate kinetic modelling using dynamic PET requires knowledge of the tracer concentration in plasma, known as the arterial input function (AIF). AIFs are usually determined by invasive blood sampling, but this is prohibitive in murine studies due to low total blood volumes. As a result of the low spatial resolution of PET, image-derived input functions (IDIFs) must be extracted from left ventricular blood pool (LVBP) ROIs of the mouse heart. This is challenging because of partial volume and spillover effects between the LVBP and myocardium, contaminating IDIFs with tissue signal. We have applied the geometric transfer matrix (GTM) method of partial volume correction (PVC) to 12 mice injected with 18F-FDG affected by a Myocardial Infarction (MI), of which 6 were treated with a drug which reduced infarction size [1]. We utilised high resolution MRI to assist in segmenting mouse hearts into 5 classes: LVBP, infarcted myocardium, healthy myocardium, lungs/body and background. The signal contribution from these 5 classes was convolved with the point spread function (PSF) of the Cambridge split magnet PET scanner and a non-linear fit was performed on the 5 measured signal components. The corrected IDIF was taken as the fitted LVBP component. It was found that the GTM PVC method could recover an IDIF with less contamination from spillover than an IDIF extracted from PET data alone. More realistic values of Ki were achieved using GTM IDIFs, which were shown to be significantly different (p<0.05) between the treated and untreated groups.
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Affiliation(s)
- Eleanor Evans
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK, CB2 0QQ ( )
| | - Guido Buonincontri
- Wolfson Brain Imaging Centre and the Department of Medicine, University of Cambridge, Cambridge, UK, CB2 0QQ ( )
| | - David Izquierdo
- Athinoula A. Martinos Center for Biomedical Imaging, 149 Thirteenth Street, Suite 2301, Charlestown, MA, 02129 ( )
| | - Carmen Methner
- Department of Medicine, University of Cambridge and is now at Oregon Health and Science University, Portland, OR, 97239 ( )
| | - Rob C Hawkes
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK, CB2 0QQ ( )
| | - Richard E Ansorge
- Department of Physics, University of Cambridge, Cambridge, UK, CB3 0HE ( )
| | - Thomas Krieg
- Member of the Department of Medicine, University of Cambridge, Cambridge, UK, CB2 0QQ ( )
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, UK, CB2 0QQ ( )
| | - Stephen J Sawiak
- Member of both the Wolfson Brain Imaging Centre, and the Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge, UK, CB2 3EB ( )
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Buonincontri G, Wood NI, Puttick SG, Ward AO, Carpenter TA, Sawiak SJ, Morton AJ. Right ventricular dysfunction in the R6/2 transgenic mouse model of Huntington's disease is unmasked by dobutamine. J Huntingtons Dis 2014; 3:25-32. [PMID: 24744818 DOI: 10.3233/jhd-130083] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Increasingly, evidence from studies in both animal models and patients suggests that cardiovascular dysfunction is important in HD. Previous studies measuring function of the left ventricle (LV) in the R6/2 model have found a clear cardiac abnormality, albeit with preserved LV systolic function. It was hypothesized that an impairment of RV function might play a role in this condition via mechanisms of ventricular interdependence. OBJECTIVE To investigate RV function in the R6/2 mouse model of Huntington's disease (HD). METHODS Cardiac cine-magnetic resonance imaging (MRI) was used to determine functional parameters in R6/2 mice. In a first experiment, these parameters were derived longitudinally to determine deterioration of cardiac function with disease progression. A second experiment compared the response to a stress test (using dobutamine) of wildtype and early-symptomatic R6/2 mice. RESULTS There was progressive deterioration of RV systolic function with age in R6/2 mice. Furthermore, beta-adrenergic stimulation with dobutamine revealed RV dysfunction in R6/2 mice before any overt symptoms of the disease were apparent. CONCLUSIONS This work adds to accumulating evidence of cardiovascular dysfunction in R6/2 mice, describing for the first time the involvement of the right ventricle. Cardiovascular dysfunction should be considered, both when treatment strategies are being designed, and when searching for biomarkers for HD.
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Affiliation(s)
- Guido Buonincontri
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK, CB2 0QQ
| | - Nigel I Wood
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, UK, CB2 3DY
| | - Simon G Puttick
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, UK, CB2 3DY
| | - Alex O Ward
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK, CB2 0QQ
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK, CB2 0QQ
| | - Stephen J Sawiak
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK, CB2 0QQ ; Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Downing Site, Cambridge, UK, CB2 3EB
| | - A Jennifer Morton
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, UK, CB2 3DY
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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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Buonincontri G, Methner C, Krieg T, Carpenter TA, Sawiak SJ. Functional assessment of the mouse heart by MRI with a 1-min acquisition. NMR IN BIOMEDICINE 2014; 27:733-737. [PMID: 24737267 DOI: 10.1002/nbm.3116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/13/2014] [Accepted: 03/14/2014] [Indexed: 06/03/2023]
Abstract
In vivo assessment of heart function in mice is important for basic and translational research in cardiology. MRI is an accurate tool for the investigation of the anatomy and function in the preclinical setting; however, the long scan duration limits its usage. We aimed to reduce the acquisition time of cine MRI to 1 min. We employed spatiotemporal compressed sensing and parallel imaging to accelerate retrospectively gated cine MRI. We compared the functional parameters derived from full and undersampled data in Cartesian and radial MRI by means of Bland-Altman plots. We found that the scan time for the whole heart could be reduced to 2 min with Cartesian sampling and to 1 min with radial sampling. Despite a reduction in the signal-to-noise ratio, the accuracy in the estimation of left and right ventricular volumes was preserved for all tested subjects. This method can be used to perform accurate functional MRI examinations in mice for high-throughput phenotyping or translational studies.
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Affiliation(s)
- Guido Buonincontri
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Methner C, Chouchani ET, Buonincontri G, Pell VR, Sawiak SJ, Murphy MP, Krieg T. Mitochondria selective S-nitrosation by mitochondria-targeted S-nitrosothiol protects against post-infarct heart failure in mouse hearts. Eur J Heart Fail 2014; 16:712-7. [PMID: 24891297 PMCID: PMC4231226 DOI: 10.1002/ejhf.100] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/12/2014] [Accepted: 03/28/2014] [Indexed: 12/01/2022] Open
Abstract
Aims Recently it has been shown that the mitochondria-targeted S-nitrosothiol MitoSNO protects against acute ischaemia/reperfusion (IR) injury by inhibiting the reactivation of mitochondrial complex I in the first minutes of reperfusion of ischaemic tissue, thereby preventing free radical formation that underlies IR injury. However, it remains unclear how this transient inhibition of mitochondrial complex I-mediated free radicals at reperfusion affects the long-term recovery of the heart following IR injury. Here we determined whether the acute protection by MitoSNO at reperfusion prevented the subsequent development of post-myocardial infarction heart failure. Methods and results Mice were subjected to 30 min left coronary artery occlusion followed by reperfusion and recovery over 28 days. MitoSNO (100 ng/kg) was applied 5 min before the onset of reperfusion followed by 20 min infusion (1 ng/kg/min). Infarct size and cardiac function were measured by magnetic resonance imaging (MRI) 24 h after infarction. MitoSNO-treated mice exhibited reduced infarct size and preserved function. In addition, MitoSNO at reperfusion improved outcome measures 28 days post-IR, including preserved systolic function (63.7 ±1.8% LVEF vs. 53.7 ± 2.1% in controls, P = 0.01) and tissue fibrosis. Conclusions MitoSNO action acutely at reperfusion reduces infarct size and protects from post-myocardial infarction heart failure. Therefore, targeted inhibition of mitochondrial complex I in the first minutes of reperfusion by MitoSNO is a rational therapeutic strategy for preventing subsequent heart failure in patients undergoing IR injury.
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Affiliation(s)
- Carmen Methner
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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Chouchani ET, Methner C, Buonincontri G, Hu CH, Logan A, Sawiak SJ, Murphy MP, Krieg T. Complex I deficiency due to selective loss of Ndufs4 in the mouse heart results in severe hypertrophic cardiomyopathy. PLoS One 2014; 9:e94157. [PMID: 24705922 PMCID: PMC3976382 DOI: 10.1371/journal.pone.0094157] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 03/11/2014] [Indexed: 01/07/2023] Open
Abstract
Mitochondrial complex I, the primary entry point for electrons into the mitochondrial respiratory chain, is both critical for aerobic respiration and a major source of reactive oxygen species. In the heart, chronic dysfunction driving cardiomyopathy is frequently associated with decreased complex I activity, from both genetic and environmental causes. To examine the functional relationship between complex I disruption and cardiac dysfunction we used an established mouse model of mild and chronic complex I inhibition through heart-specific Ndufs4 gene ablation. Heart-specific Ndufs4-null mice had a decrease of ∼50% in complex I activity within the heart, and developed severe hypertrophic cardiomyopathy as assessed by magnetic resonance imaging. The decrease in complex I activity, and associated cardiac dysfunction, occurred absent an increase in mitochondrial hydrogen peroxide levels in vivo, accumulation of markers of oxidative damage, induction of apoptosis, or tissue fibrosis. Taken together, these results indicate that diminished complex I activity in the heart alone is sufficient to drive hypertrophic cardiomyopathy independently of alterations in levels of mitochondrial hydrogen peroxide or oxidative damage.
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Affiliation(s)
- Edward T. Chouchani
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- MRC Mitochondrial Biology Unit, Cambridge, United Kingdom
| | - Carmen Methner
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | | | - Chou-Hui Hu
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Angela Logan
- MRC Mitochondrial Biology Unit, Cambridge, United Kingdom
| | - Stephen J. Sawiak
- Wolfson Brain Imaging Centre, University of Cambridge, United Kingdom
| | | | - Thomas Krieg
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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Buonincontri G, Methner C, Krieg T, Hawkes RC, Carpenter TA, Sawiak SJ. PET/MRI assessment of the infarcted mouse heart. NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT 2014; 734:152-155. [PMID: 26005235 PMCID: PMC4441008 DOI: 10.1016/j.nima.2013.08.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Heart failure originating from myocardial infarction (MI) is a leading cause of death worldwide. Mouse models of ischaemia and reperfusion injury (I/R) are used to study the effects of novel treatment strategies targeting MI, however staging disease and treatment efficacy is a challenge. Damage and recovery can be assessed on the cellular, tissue or whole-organ scale but these are rarely measured in concert. Here, for the first time, we present data showing measures of injury in infarcted mice using complementary techniques for multi-modal characterisation of the heart. We use in vivo magnetic resonance imaging (MRI) to assess heart function with cine-MRI, hindered perfusion with late gadolinium enhancement imaging and muscular function with displacement encoded with stimulated echoes (DENSE) MRI. These measures are followed by positron emission tomography (PET) with 18-F-fluorodeoxyglucose to assess cellular metabolism. We demonstrate a protocol combining each of these measures for the same animal in the same imaging session and compare how the different markers can be used to quantify cardiac recovery on different scales following injury.
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Affiliation(s)
- Guido Buonincontri
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Carmen Methner
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Thomas Krieg
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Robert C Hawkes
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Stephen J Sawiak
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom ; Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
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Riociguat reduces infarct size and post-infarct heart failure in mouse hearts: insights from MRI/PET imaging. PLoS One 2013; 8:e83910. [PMID: 24391843 PMCID: PMC3877128 DOI: 10.1371/journal.pone.0083910] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/08/2013] [Indexed: 11/19/2022] Open
Abstract
AIM Stimulation of the nitric oxide (NO)--soluble guanylate (sGC)--protein kinase G (PKG) pathway confers protection against acute ischaemia/reperfusion injury, but more chronic effects in reducing post-myocardial infarction (MI) heart failure are less defined. The aim of this study was to not only determine whether the sGC stimulator riociguat reduces infarct size but also whether it protects against the development of post-MI heart failure. METHODS AND RESULTS Mice were subjected to 30 min ischaemia via ligation of the left main coronary artery to induce MI and either placebo or riociguat (1.2 µmol/l) were given as a bolus 5 min before and 5 min after onset of reperfusion. After 24 hours, both, late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) and (18)F-FDG-positron emission tomography (PET) were performed to determine infarct size. In the riociguat-treated mice, the resulting infarct size was smaller (8.5 ± 2.5% of total LV mass vs. 21.8% ± 1.7%. in controls, p = 0.005) and LV systolic function analysed by MRI was better preserved (60.1% ± 3.4% of preischaemic vs. 44.2% ± 3.1% in controls, p = 0.005). After 28 days, LV systolic function by echocardiography treated group was still better preserved (63.5% ± 3.2% vs. 48.2% ± 2.2% in control, p = 0.004). CONCLUSION Taken together, mice treated acutely at the onset of reperfusion with the sGC stimulator riociguat have smaller infarct size and better long-term preservation of LV systolic function. These findings suggest that sGC stimulation during reperfusion therapy may be a powerful therapeutic treatment strategy for preventing post-MI heart failure.
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Buonincontri G, Methner C, Carpenter TA, Hawkes RC, Sawiak SJ, Krieg T. MRI and PET in mouse models of myocardial infarction. J Vis Exp 2013:e50806. [PMID: 24378323 PMCID: PMC4110968 DOI: 10.3791/50806] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies. In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment. In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.
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Affiliation(s)
- Guido Buonincontri
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, Unversity of Cambridge
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