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Wan J, Zhang Z, Wu C, Tian S, Zang Y, Jin G, Sun Q, Wang P, Luan X, Yang Y, Zhan X, Ye LL, Duan DD, Liu X, Zhang W. Astragaloside IV derivative HHQ16 ameliorates infarction-induced hypertrophy and heart failure through degradation of lncRNA4012/9456. Signal Transduct Target Ther 2023; 8:414. [PMID: 37857609 PMCID: PMC10587311 DOI: 10.1038/s41392-023-01660-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/10/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023] Open
Abstract
Reversing ventricular remodeling represents a promising treatment for the post-myocardial infarction (MI) heart failure (HF). Here, we report a novel small molecule HHQ16, an optimized derivative of astragaloside IV, which effectively reversed infarction-induced myocardial remodeling and improved cardiac function by directly acting on the cardiomyocyte to reverse hypertrophy. The effect of HHQ16 was associated with a strong inhibition of a newly discovered Egr2-affiliated transcript lnc9456 in the heart. While minimally expressed in normal mouse heart, lnc9456 was dramatically upregulated in the heart subjected to left anterior descending coronary artery ligation (LADL) and in cardiomyocytes subjected to hypertrophic stimulation. The critical role of lnc9456 in cardiomyocyte hypertrophy was confirmed by specific overexpression and knockout in vitro. A physical interaction between lnc9456 and G3BP2 increased NF-κB nuclear translocation, triggering hypertrophy-related cascades. HHQ16 physically bound to lnc9456 with a high-affinity and induced its degradation. Cardiomyocyte-specific lnc9456 overexpression induced, but knockout prevented LADL-induced, cardiac hypertrophy and dysfunction. HHQ16 reversed the effect of lnc9456 overexpression while lost its protective role when lnc9456 was deleted, further confirming lnc9456 as the bona fide target of HHQ16. We further identified the human ortholog of lnc9456, also an Egr2-affiliated transcript, lnc4012. Similarly, lnc4012 was significantly upregulated in hypertrophied failing hearts of patients with dilated cardiomyopathy. HHQ16 also specifically bound to lnc4012 and caused its degradation and antagonized its hypertrophic effects. Targeted degradation of pathological increased lnc4012/lnc9456 by small molecules might serve as a novel promising strategy to regress infarction-induced cardiac hypertrophy and HF.
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Affiliation(s)
- Jingjing Wan
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Zhen Zhang
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Chennan Wu
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Saisai Tian
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Yibei Zang
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Ge Jin
- School of Pharmacy, Second Military Medical University, Shanghai, PR China
| | - Qingyan Sun
- China Institute of Pharmaceutical Industry, Shanghai, PR China
| | - Pin Wang
- Key Laboratory of Medical Immunology and Institute of Immunology, Second Military Medical University, Shanghai, PR China
| | - Xin Luan
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | - Yili Yang
- China Regional Research Centre, International Centre of Genetic Engineering & Biotechnology, Taizhou, PR China
| | - Xuelin Zhan
- China Regional Research Centre, International Centre of Genetic Engineering & Biotechnology, Taizhou, PR China
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Tianjin, PR China
| | - Lingyu Linda Ye
- Center for Phenomics of Traditional Chinese Medicine, Hospital of Traditional Chinese Medicine Affiliated to Southwest Medical University, Southwest Medical University, Luzhou, PR China
| | - Dayue Darrel Duan
- Center for Phenomics of Traditional Chinese Medicine, Hospital of Traditional Chinese Medicine Affiliated to Southwest Medical University, Southwest Medical University, Luzhou, PR China.
- Key Laboratory of Autoimmune Diseases and Precision Medicine, People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, PR China.
| | - Xia Liu
- School of Pharmacy, Second Military Medical University, Shanghai, PR China.
| | - Weidong Zhang
- School of Pharmacy, Second Military Medical University, Shanghai, PR China.
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
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Xu Z, Tao B, Liu C, Han D, Zhang J, Liu J, Li S, Li W, Wang J, Liang J, Cao F. Three-dimensional quantitative assessment of myocardial infarction via multimodality fusion imaging: methodology, validation, and preliminary clinical application. Quant Imaging Med Surg 2021; 11:3175-3189. [PMID: 34249644 PMCID: PMC8250027 DOI: 10.21037/qims-20-702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 02/24/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND The precise assessment of myocardial infarction (MI) is crucial both for therapeutic interventions in old MI and the development of new and effective techniques to repair injured myocardium. A novel method was developed to assess left ventricular (LV) quantitatively infarction through three-dimensional (3D) multimodality fusion based on computed tomography angiography (CTA) and technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography (SPECT) images. This study sought to develop a 3D quantitative method for MI for pre-clinical study and clinical application. METHODS Three months after the MI models were established in 20 minipigs, CTA and SPECT images were acquired separately, which were then aligned automatically with the constraints of the shape and the whole heart and LV myocardium position. Infarct ratios were quantified based on the 3D fusion images. The quantitative assessment was then experimentally validated via an ex vivo histology analysis using triphenyl-tetrazolium-chloride staining and subsequently applied to post-MI patients (n=8). RESULTS The location of an infarct identified by the SPECT was consistent with that identified by an ex vivo heart in a 3D space. Infarct size determined by CTA-SPECT was correlated with infarct size assessed by triphenyl-tetrazolium-chloride pathology {27.6% [interquartile range (IQR) 17.1-34.7%] vs. 24.1% (IQR 14.7-32.5%), r2=0.99, P<0.01}. In clinical cases, the CTA-SPECT 3D fusion quantitative results were significantly correlated with the quantitative perfusion SPECT results (r=0.976, P<0.01). CONCLUSIONS The proposed 3D fusion quantitative assessment method provides reliable and intuitive evaluations of infarction. This novel quantification technique enables whole heart quantification for the pre-operation evaluation and post-diagnosis management of old MI patients. It could also be applied to the design of 3D-printed cardiac patches.
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Affiliation(s)
- Zhenzhen Xu
- School of Life Science and Technology, Xidian University, Xi’an, China
| | - Bo Tao
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
- Department of Cardiology, Hainan Hospital of Chinese PLA General Hospital, Sanya, China
| | - Chuanbin Liu
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Dong Han
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Jibin Zhang
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Junsong Liu
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
- Department of Cardiology, First Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Sulei Li
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Weijie Li
- Department of Cardiology, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Jing Wang
- Department of Nuclear Medicine, Xijing Hospital, Air Force Medical University, Xi’an, China
| | - Jimin Liang
- School of Electronic Engineering, Xidian University, Xi’an, China
| | - Feng Cao
- Department of Geriatric Cardiology, Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
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Mohindra P, Desai TA. Micro- and nanoscale biophysical cues for cardiovascular disease therapy. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2021; 34:102365. [PMID: 33571682 PMCID: PMC8217090 DOI: 10.1016/j.nano.2021.102365] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 01/15/2021] [Indexed: 11/19/2022]
Abstract
After cardiovascular injury, numerous pathological processes adversely impact the homeostatic function of cardiomyocyte, macrophage, fibroblast, endothelial cell, and vascular smooth muscle cell populations. Subsequent malfunctioning of these cells may further contribute to cardiovascular disease onset and progression. By modulating cellular responses after injury, it is possible to create local environments that promote wound healing and tissue repair mechanisms. The extracellular matrix continuously provides these mechanosensitive cell types with physical cues spanning the micro- and nanoscale to influence behaviors such as adhesion, morphology, and phenotype. It is therefore becoming increasingly compelling to harness these cell-substrate interactions to elicit more native cell behaviors that impede cardiovascular disease progression and enhance regenerative potential. This review discusses recent in vitro and preclinical work that have demonstrated the therapeutic implications of micro- and nanoscale biophysical cues on cell types adversely affected in cardiovascular diseases - cardiomyocytes, macrophages, fibroblasts, endothelial cells, and vascular smooth muscle cells.
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Affiliation(s)
- Priya Mohindra
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States
| | - Tejal A Desai
- UC Berkeley-UCSF Graduate Program in Bioengineering, San Francisco, CA, United States; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA; Department of Bioengineering, University of California, Berkeley, Berkeley, CA.
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Non-coding RNAs: emerging players in cardiomyocyte proliferation and cardiac regeneration. Basic Res Cardiol 2020; 115:52. [PMID: 32748089 PMCID: PMC7398957 DOI: 10.1007/s00395-020-0816-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 07/22/2020] [Indexed: 02/07/2023]
Abstract
Soon after birth, the regenerative capacity of the mammalian heart is lost, cardiomyocytes withdraw from the cell cycle and demonstrate a minimal proliferation rate. Despite improved treatment and reperfusion strategies, the uncompensated cardiomyocyte loss during injury and disease results in cardiac remodeling and subsequent heart failure. The promising field of regenerative medicine aims to restore both the structure and function of damaged tissue through modulation of cellular processes and regulatory mechanisms involved in cardiac cell cycle arrest to boost cardiomyocyte proliferation. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) are functional RNA molecules with no protein-coding function that have been reported to engage in cardiac regeneration and repair. In this review, we summarize the current understanding of both the biological functions and molecular mechanisms of ncRNAs involved in cardiomyocyte proliferation. Furthermore, we discuss their impact on the structure and contractile function of the heart in health and disease and their application for therapeutic interventions.
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Li W. Biomechanics of infarcted left Ventricle-A review of experiments. J Mech Behav Biomed Mater 2020; 103:103591. [PMID: 32090920 DOI: 10.1016/j.jmbbm.2019.103591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 01/14/2023]
Abstract
Myocardial infarction (MI) is one of leading diseases to contribute to annual death rate of 5% in the world. In the past decades, significant work has been devoted to this subject. Biomechanics of infarcted left ventricle (LV) is associated with MI diagnosis, understanding of remodelling, MI micro-structure and biomechanical property characterizations as well as MI therapy design and optimization, but the subject has not been reviewed presently. In the article, biomechanics of infarcted LV was reviewed in terms of experiments achieved in the subject so far. The concerned content includes experimental remodelling, kinematics and kinetics of infarcted LVs. A few important issues were discussed and several essential topics that need to be investigated further were summarized. Microstructure of MI tissue should be observed even carefully and compared between different methods for producing MI scar in the same animal model, and eventually correlated to passive biomechanical property by establishing innovative constitutive laws. More uniaxial or biaxial tensile tests are desirable on MI, border and remote tissues, and viscoelastic property identification should be performed in various time scales. Active contraction experiments on LV wall with MI should be conducted to clarify impaired LV pumping function and supply necessary data to the function modelling. Pressure-volume curves of LV with MI during diastole and systole for the human are also desirable to propose and validate constitutive laws for LV walls with MI.
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Affiliation(s)
- Wenguang Li
- School of Engineering, University of Glasgow, Glasgow, G12 8QQ, UK.
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Reinstadler SJ, Stiermaier T, Liebetrau J, Fuernau G, Eitel C, de Waha S, Desch S, Reil JC, Pöss J, Metzler B, Lücke C, Gutberlet M, Schuler G, Thiele H, Eitel I. Prognostic Significance of Remote Myocardium Alterations Assessed by Quantitative Noncontrast T1 Mapping in ST-Segment Elevation Myocardial Infarction. JACC Cardiovasc Imaging 2017. [PMID: 28624398 DOI: 10.1016/j.jcmg.2017.03.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES This study assessed the prognostic significance of remote zone native T1 alterations for the prediction of clinical events in a population with ST-segment elevation myocardial infarction (STEMI) who were treated by primary percutaneous coronary intervention (PPCI) and compared it with conventional markers of infarct severity. BACKGROUND The exact role and incremental prognostic relevance of remote myocardium native T1 mapping alterations assessed by cardiac magnetic resonance (CMR) after STEMI remains unclear. METHODS We included 255 consecutive patients with STEMI who were reperfused within 12 h after symptom onset. CMR core laboratory analysis was performed to assess left ventricular (LV) function, standard infarct characteristics, and native T1 values of the remote, noninfarcted myocardium. The primary endpoint was a composite of death, reinfarction, and new congestive heart failure within 6 months (major adverse cardiac events [MACE]). RESULTS Patients with increased remote zone native T1 values (>1,129 ms) had significantly larger infarcts (p = 0.012), less myocardial salvage (p = 0.002), and more pronounced LV dysfunction (p = 0.011). In multivariable analysis, remote zone native T1 was independently associated with MACE after adjusting for clinical risk factors (p = 0.001) or other CMR variables (p = 0.007). In C-statistics, native T1 of remote myocardium provided incremental prognostic information beyond clinical risk factors, LV ejection fraction, and other markers of infarct severity (all p < 0.05). The addition of remote zone native T1 to a model of prognostic CMR parameters (ejection fraction, infarct size, and myocardial salvage index) led to net reclassification improvement of 0.82 (95% confidence interval: 0.46 to 1.17; p < 0.001) and to an integrated discrimination improvement of 0.07 (95% confidence interval: 0.02 to 0.13; p = 0.01). CONCLUSIONS In STEMI patients treated by PPCI, evaluation of remote zone alterations by quantitative noncontrast T1 mapping provided independent and incremental prognostic information in addition to clinical risk factors and traditional CMR outcome markers. Remote zone alterations may thus represent a novel therapeutic target and a useful parameter for optimized risk stratification. (Effect of Conditioning on Myocardial Damage in STEMI [LIPSIA-COND]; NCT02158468).
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Affiliation(s)
- Sebastian J Reinstadler
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany; University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Stiermaier
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Johanna Liebetrau
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Georg Fuernau
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Charlotte Eitel
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Suzanne de Waha
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Steffen Desch
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Jan-Christian Reil
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Janine Pöss
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Bernhard Metzler
- University Clinic of Internal Medicine III, Cardiology and Angiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christian Lücke
- Department of Diagnostic and Interventional Radiology, University of Leipzig-Heart Center, Leipzig, Germany
| | - Matthias Gutberlet
- Department of Diagnostic and Interventional Radiology, University of Leipzig-Heart Center, Leipzig, Germany
| | - Gerhard Schuler
- Department of Internal Medicine and Cardiology, University of Leipzig-Heart Center, Leipzig, Germany
| | - Holger Thiele
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany
| | - Ingo Eitel
- University Heart Center Lübeck, Medical Clinic II, Department of Cardiology, Angiology and Intensive Care Medicine, University of Lübeck, Lübeck, Germany; German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, Lübeck, Germany.
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Postinfarct Left Ventricular Remodelling: A Prevailing Cause of Heart Failure. Cardiol Res Pract 2016; 2016:2579832. [PMID: 26989555 PMCID: PMC4775793 DOI: 10.1155/2016/2579832] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/13/2016] [Accepted: 01/17/2016] [Indexed: 12/11/2022] Open
Abstract
Heart failure is a chronic disease with high morbidity and mortality, which represents a growing challenge in medicine. A major risk factor for heart failure with reduced ejection fraction is a history of myocardial infarction. The expansion of a large infarct scar and subsequent regional ventricular dilatation can cause postinfarct remodelling, leading to significant enlargement of the left ventricular chamber. It has a negative prognostic value, because it precedes the clinical manifestations of heart failure. The characteristics of the infarcted myocardium predicting postinfarct remodelling can be studied with cardiac magnetic resonance and experimental imaging modalities such as diffusion tensor imaging can identify the changes in the architecture of myocardial fibers. This review discusses all the aspects related to postinfarct left ventricular remodelling: definition, pathogenesis, diagnosis, consequences, and available therapies, together with experimental interventions that show promising results against postinfarct remodelling and heart failure.
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Jonker SS, Louey S. Endocrine and other physiologic modulators of perinatal cardiomyocyte endowment. J Endocrinol 2016; 228:R1-18. [PMID: 26432905 PMCID: PMC4677998 DOI: 10.1530/joe-15-0309] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/01/2015] [Indexed: 01/09/2023]
Abstract
Immature contractile cardiomyocytes proliferate to rapidly increase cell number, establishing cardiomyocyte endowment in the perinatal period. Developmental changes in cellular maturation, size and attrition further contribute to cardiac anatomy. These physiological processes occur concomitant with a changing hormonal environment as the fetus prepares itself for the transition to extrauterine life. There are complex interactions between endocrine, hemodynamic and nutritional regulators of cardiac development. Birth has been long assumed to be the trigger for major differences between the fetal and postnatal cardiomyocyte growth patterns, but investigations in normally growing sheep and rodents suggest this may not be entirely true; in sheep, these differences are initiated before birth, while in rodents they occur after birth. The aim of this review is to draw together our understanding of the temporal regulation of these signals and cardiomyocyte responses relative to birth. Further, we consider how these dynamics are altered in stressed and suboptimal intrauterine environments.
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Affiliation(s)
- S S Jonker
- Knight Cardiovascular Institute Center for Developmental HealthOregon Health and Science University, Portland, Oregon 97239, USA
| | - S Louey
- Knight Cardiovascular Institute Center for Developmental HealthOregon Health and Science University, Portland, Oregon 97239, USA
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Lee LC, Sundnes J, Genet M, Wenk JF, Wall ST. An integrated electromechanical-growth heart model for simulating cardiac therapies. Biomech Model Mechanobiol 2015; 15:791-803. [PMID: 26376641 DOI: 10.1007/s10237-015-0723-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 08/25/2015] [Indexed: 01/27/2023]
Abstract
An emerging class of models has been developed in recent years to predict cardiac growth and remodeling (G&R). We recently developed a cardiac G&R constitutive model that predicts remodeling in response to elevated hemodynamics loading, and a subsequent reversal of the remodeling process when the loading is reduced. Here, we describe the integration of this G&R model to an existing strongly coupled electromechanical model of the heart. A separation of timescale between growth deformation and elastic deformation was invoked in this integrated electromechanical-growth heart model. To test our model, we applied the G&R scheme to simulate the effects of myocardial infarction in a realistic left ventricular (LV) geometry using the finite element method. We also simulate the effects of a novel therapy that is based on alteration of the infarct mechanical properties. We show that our proposed model is able to predict key features that are consistent with experiments. Specifically, we show that the presence of a non-contractile infarct leads to a dilation of the left ventricle that results in a rightward shift of the pressure volume loop. Our model also predicts that G&R is attenuated by a reduction in LV dilation when the infarct stiffness is increased.
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Affiliation(s)
- Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | | | - Martin Genet
- Institute of Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Jonathan F Wenk
- Department of Mechanical Engineering, University of Kentucky, Lexington, KY, USA
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Meijers WC, van der Velde AR, Pascual-Figal DA, de Boer RA. Galectin-3 and post-myocardial infarction cardiac remodeling. Eur J Pharmacol 2015; 763:115-21. [PMID: 26101067 DOI: 10.1016/j.ejphar.2015.06.025] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 06/01/2015] [Accepted: 06/15/2015] [Indexed: 01/13/2023]
Abstract
This review summarizes the current literature regarding the involvement and the putative role(s) of galectin-3 in post-myocardial infarction cardiac remodeling. Post-myocardial infarction remodeling is characterized by acute loss of myocardium, which leads to structural and biomechanical changes in order to preserve cardiac function. A hallmark herein is fibrosis formation, both in the early and late phase following acute myocardial infarction. Galectin-3, a β-galactoside-binding lectin, which is a shared factor in fibrosis formation in multiple organs, has an established role in cardiac fibrosis in the setting of pressure overload, neuro-endocrine activation and hypertension, but its role in post- myocardial infarction remodeling has received less attention. However, accumulative experimental studies have shown that myocardial galectin-3 expression is upregulated after myocardial infarction, both on mRNA and protein level. This already occurs shortly after myocardial infarction in the infarcted and border zone area, and also at a later stage in the spared myocardium, contributing to tissue repair and fibrosis. This is associated with typical aspects of fibrosis formation, such as apposition of matricellular proteins and increased factors of collagen turnover. Interestingly, myocardial fibrosis in experimental post-myocardial infarction cardiac remodeling could be attenuated by galectin-3 inhibition. In clinical studies, circulating galectin-3 levels have been shown to identify patients at risk for new-onset heart failure and atrial fibrillation. Circulating galectin-3 levels also predict progressive left ventricular dilatation after myocardial infarction. From literature we conclude that galectin-3 is an active player in cardiac remodeling after myocardial infarction. Future studies should focus on the dynamics of galectin-3 activation after myocardial infarction, and study the possibilities to target galectin-3.
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Affiliation(s)
- Wouter C Meijers
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands
| | - A Rogier van der Velde
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands
| | - Domingo A Pascual-Figal
- University of Murcia, University Hospital Virgen de la Arrixaca, Department of Cardiology, Spain
| | - Rudolf A de Boer
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Groningen, The Netherlands.
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Zhang P, Li T, Griffith BP, Wu ZJ. Multiscale Characterization of Impact of Infarct Size on Myocardial Remodeling in an Ovine Infarct Model. Cells Tissues Organs 2014; 200:349-62. [PMID: 26540290 DOI: 10.1159/000435875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2015] [Indexed: 11/19/2022] Open
Abstract
The surviving myocardium initially compensates the loss of injured myocardium after myocardial infarction (MI) and gradually becomes progressively dysfunctional. There have been limited studies on the effect of infarct size on temporal and spatial alterations in the myocardium during progressive myocardial remodeling. MI with three infarct sizes, i.e. 15, 25 and 35% of the left ventricular (LV) wall, was created in an ovine infarction model. The progressive LV remodeling over a 12-week period was studied. Echocardiography, sonomicrometry, and histological and molecular analyses were carried out to evaluate cardiac function, regional tissue contractile function, structural remodeling and cardiomyocyte hypertrophy, and calcium handling proteins. Twelve weeks after MI, the 15, 25 and 35% MI groups had normalized LV end diastole volumes of 1.4 ± 0.2, 1.7 ± 0.3 and 2.0 ± 0.4 ml/kg, normalized end systole volumes of 1.0 ± 0.1, 1.0 ± 0.2 and 1.3 ± 0.3 ml/kg and LV ejection fractions of 43 ± 3, 42 ± 6 and 34 ± 4%, respectively. They all differed from the sham group (p < 0.05). All the three MI groups exhibited larger wall areal expansion (remodeling strain), larger cardiomyocyte size and altered expression of calcium handing proteins in the adjacent myocardium compared to the remote counterpart from the infarct. A significant correlation was found between cardiomyocyte size and remodeling strain in the adjacent zone. A comparative analysis among the three MI groups showed that a larger infarct size (35 vs. 15% MI) was associated with larger remodeling strain, more serious impairment in the cellular structure and composition, and regional contractile function at regional tissue level and LV function at organ level.
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Affiliation(s)
- Pei Zhang
- Artificial Organs Laboratory, Department of Surgery, University of Maryland School of Medicine, Baltimore, Md., USA
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Rolf A, Assmus B, Schächinger V, Rixe J, Möllmann S, Möllmann H, Dimmeler S, Zeiher AM, Hamm CW, Dill T. Maladaptive hypertrophy after acute myocardial infarction positive effect of bone marrow-derived stem cell therapy on regional remodeling measured by cardiac MRI. Clin Res Cardiol 2011; 100:983-92. [DOI: 10.1007/s00392-011-0330-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 05/30/2011] [Indexed: 11/27/2022]
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Anagnostopoulos CD, Cokkinos DV. Prediction of left ventricular remodelling by radionuclide imaging. Eur J Nucl Med Mol Imaging 2011; 38:1120-3. [DOI: 10.1007/s00259-011-1797-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Post-myocardial infarction left ventricular myocyte remodeling: are there gender differences in rats? Cardiovasc Pathol 2010; 20:e189-95. [PMID: 21081276 DOI: 10.1016/j.carpath.2010.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 08/06/2010] [Accepted: 09/14/2010] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Previous studies have shown gender differences in left ventricular remodeling after myocardial infarction. Results are varied, however, and reliable, comprehensive data for changes in cardiac myocyte shape are not available. METHODS Young adult female and male Sprague-Dawley rats were used in this study and randomly assigned to the myocardial infarction and sham myocardial infarction groups. Myocardial infarction was produced by ligation of the left descending coronary artery. Four weeks after surgery, left ventricular echocardiography and hemodynamics were performed before isolating myocytes for size determination. RESULTS In general, left ventricular functional changes after myocardial infarction were comparable. Females developed slightly, but significantly, more left ventricular hypertrophy than males, and this was reflected by the relative increases in left ventricular myocyte volume. In both males and females, however, myocyte hypertrophy was due exclusively to lengthening of myocytes with no change in myocyte cross-sectional area. CONCLUSIONS This study demonstrates that post-myocardial infarction changes in LV function and myocyte remodeling are remarkably similar in young adult male and female rats.
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Time course of infarct healing and left ventricular remodelling in patients with reperfused ST segment elevation myocardial infarction using comprehensive magnetic resonance imaging. Eur Radiol 2010; 21:693-701. [PMID: 20865262 DOI: 10.1007/s00330-010-1963-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 08/02/2010] [Accepted: 08/03/2010] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To describe the time course of myocardial infarct (MI) healing and left ventricular (LV) remodelling and to assess factors predicting LV remodelling using cardiac MRI. METHODS In 58 successfully reperfused MI patients, MRI was performed at baseline, 4 months (4M), and 1 year (1Y) post MI RESULTS: Infarct size decreased between baseline and 4M (p < 0.001), but not at 1Y; i.e. 18 ± 11%, 12 ± 8%, 11 ± 6% of LV mass respectively; this was associated with LV mass reduction. Infarct and adjacent wall thinning was found at 4M, whereas significant remote wall thinning was measured at 1Y. LV end-diastolic and end-systolic volumes significantly increased at 1Y, p < 0.05 at 1Y vs. baseline and vs. 4M; this was associated with increased LV sphericity index. No regional or global LV functional improvement was found at follow-up. Baseline infarct size was the strongest predictor of adverse LV remodelling. CONCLUSIONS Infarct healing, with shrinkage of infarcted myocardium and wall thinning, occurs early post-MI as reflected by loss in LV mass and adjacent myocardial remodelling. Longer follow-up demonstrates ongoing remote myocardial and ventricular remodelling. Infarct size at baseline predicts long-term LV remodelling and represents an important parameter for tailoring future post-MI pharmacological therapies designed to prevent heart failure.
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Kramer CM. Insights into myocardial microstructure during infarct healing and remodeling: pathologists need not apply. Circ Cardiovasc Imaging 2009; 2:4-5. [PMID: 19808557 DOI: 10.1161/circimaging.108.841619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Monreal G, Nicholson LM, Han B, Joshi MS, Phillips AB, Wold LE, Bauer JA, Gerhardt MA. Cytoskeletal remodeling of desmin is a more accurate measure of cardiac dysfunction than fibrosis or myocyte hypertrophy. Life Sci 2008; 83:786-94. [DOI: 10.1016/j.lfs.2008.09.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 09/08/2008] [Accepted: 09/21/2008] [Indexed: 11/29/2022]
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Lee TM, Lin MS, Chang NC. Effect of ATP-sensitive potassium channel agonists on ventricular remodeling in healed rat infarcts. J Am Coll Cardiol 2008; 51:1309-18. [PMID: 18371564 DOI: 10.1016/j.jacc.2007.11.067] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 10/29/2007] [Accepted: 11/19/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The purpose of this study was to determine whether ATP-sensitive potassium (K(ATP)) channel agonists exert a beneficial effect on the structural, functional, and molecular features of the remodeling heart in infarcted rats. BACKGROUND Myocardial K(ATP) channels have been implicated in the ventricular remodeling after myocardial infarction by inhibition of 70-kDa S6 (p70S6) kinase. METHODS Male Wistar rats after induction of myocardial infarction were randomized to either vehicle, agonists of K(ATP) channels nicorandil and pinacidil, an antagonist of K(ATP) channels glibenclamide, or a combination of nicorandil and glibenclamide or pinacidil and glibenclamide for 4 weeks. To verify the role of p70S6 kinase in ventricular remodeling, rapamycin was also assessed. RESULTS Significant ventricular hypertrophy was detected by increased myocyte size at the border zone isolated by enzymatic dissociation after infarction. Increased synthesis of p70S6 kinase messenger ribonucleic acid after infarction in vehicle-treated rats was confirmed by reverse transcription-polymerase chain reaction, consistent with the results of immunohistochemistry and Western blot for phosphorylated p70S6 kinase. Rats in the nicorandil- and pinacidil-treated groups significantly attenuated cardiomyocyte hypertrophy and phosphorylated p70S6 kinase expression with similar potency, as compared with vehicle. The beneficial effects of nicorandil and pinacidil were abolished by administering either glibenclamide or 5-hydroxydecanoate. Addition of rapamycin attenuated ventricular remodeling and did not have additional beneficial effects compared with those seen in rats treated with either nicorandil or pinacidil alone. CONCLUSIONS Activation of K(ATP) channels by either nicorandil or pinacidil can attenuate ventricular remodeling, probably through a p70S6 kinase-dependent pathway after infarction.
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Affiliation(s)
- Tsung-Ming Lee
- Cardiology Section, Department of Medicine, Taipei Medical University and Chi-Mei Medical Center, Tainan, Taiwan
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Left Ventricular Postmyocardial Infarction Remodeling Studied by Combining MR-Tagging With Delayed MR Contrast Enhancement. Invest Radiol 2008; 43:219-28. [DOI: 10.1097/rli.0b013e318161613e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Jacquier A, Higgins CB, Martin AJ, Do L, Saloner D, Saeed M. Injection of Adeno-associated Viral Vector–Encoding Vascular Endothelial Growth Factor Gene in Infarcted Swine Myocardium: MR Measurements of Left Ventricular Function and Strain. Radiology 2007; 245:196-205. [PMID: 17885189 DOI: 10.1148/radiol.2451061077] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively investigate the long-term effect of adeno-associated viral (AAV) vector-encoding vascular endothelial growth factor gene (VEGF) (AAV-VEGF) on left ventricular (LV) mass and volumes, as well as on regional contractility and circumferential strain, in a swine model of reperfused myocardial infarction. MATERIALS AND METHODS All experimental procedures received approval from the institutional committee on animal research. Of 16 pigs subjected to reperfused myocardial infarction, six were treated, six were controls, and four died during the ischemic intervention. In six animals, cardiac-specific AAV-VEGF was injected into the periinfarcted and infarcted myocardium 1 hour after reperfusion. Magnetic resonance (MR) imaging was performed at 3 days and 8 weeks after infarction by using cine, tagged, and delayed enhancement (with gadoterate meglumine) sequences to measure global and regional LV function and infarct size. At postmortem examination, tissue samples stained with isolectin B4, Masson trichrome, and hematoxylin-eosin were used to characterize injured myocardium. Two-tailed Student t test was used for statistical analysis. RESULTS Six treated animals showed no change in mean LV ejection fraction after 8 weeks (40.3%+/-0.9 [standard error of the mean] vs 41.0%+/-0.7) in contrast to a decrease measured in six control animals (41.4%+/-0.7 vs 36.1%+/-0.6, P<.001). AAV-VEGF improved wall thickening and circumferential strain in periinfarcted and remote myocardium. A greater reduction in gadoterate meglumine-enhanced infarct area was measured in treated animals (18.6%+/-1.5 of the LV mass at 3 days vs 9.8%+/-1.0 of the LV mass at 8 weeks, P<.001) compared with control animals (17.7%+/-2.0 vs 14.8%+/-1.0, P=.008). Findings at histopathologic evaluation indicated an increase in vascular density and a decrease in myocyte diameter in the periinfarcted myocardium of treated, compared with control, animals. CONCLUSION Angiogenesis and arteriogenesis induced by VEGF genes improved regional myocardial strain and wall thickening and preserved ejection fraction after infarction.
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Affiliation(s)
- Alexis Jacquier
- Department of Radiology, University of California San Francisco, 513 Parnassus Ave, HSW 207 B, San Francisco, CA 94134-0628, USA
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Gilson WD, Epstein FH, Yang Z, Xu Y, Prasad KMR, Toufektsian MC, Laubach VE, French BA. Borderzone Contractile Dysfunction Is Transiently Attenuated and Left Ventricular Structural Remodeling Is Markedly Reduced Following Reperfused Myocardial Infarction in Inducible Nitric Oxide Synthase Knockout Mice. J Am Coll Cardiol 2007; 50:1799-807. [DOI: 10.1016/j.jacc.2007.07.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 06/22/2007] [Accepted: 07/31/2007] [Indexed: 11/28/2022]
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French BA, Kramer CM. Mechanisms of Post-Infarct Left Ventricular Remodeling. ACTA ACUST UNITED AC 2007; 4:185-196. [PMID: 18690295 DOI: 10.1016/j.ddmec.2007.12.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heart failure secondary to myocardial infarction (MI) remains a major source of morbidity and mortality. Long-term outcome after MI can be largely be defined in terms of its impact on the size and shape of the left ventricle (i.e., LV remodeling). Three major mechanisms contribute to LV remodeling: 1) early infarct expansion, 2) subsequent infarct extension into adjacent noninfarcted myocardium, and 3) late hypertrophy in the remote LV. Future developments in preventing post-MI heart failure will depend not only on identifying drugs targeting each of these individual mechanisms, but also on diagnostic techniques capable of assessing efficacy against each mechanism.
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Affiliation(s)
- Brent A French
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908
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Lee TM, Lin MS, Chang NC. Inhibition of histone deacetylase on ventricular remodeling in infarcted rats. Am J Physiol Heart Circ Physiol 2007; 293:H968-77. [PMID: 17400721 DOI: 10.1152/ajpheart.00891.2006] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Histone deacetylase (HDAC) determines the acetylation status of histones and, thereby, controls the regulation of gene expression. HDAC inhibitors have been shown to inhibit cardiomyocyte growth in vitro and in vivo. We assessed whether HDAC inhibitors exert a beneficial effect on the remodeling heart in infarcted rats. At 24 h after ligation of the left anterior descending artery, male Wistar rats were randomized to vehicle, HDAC inhibitors [valproic acid (VPA) and tributyrin], an agonist of HDAC (theophylline), VPA + theophylline, or tributyrin + theophylline for 4 wk. Significant ventricular hypertrophy was detected as increased myocyte size at the border zone isolated by enzymatic dissociation after infarction. Cardiomyocyte hypertrophy and collagen formation at the remote region and border zone were significantly attenuated by VPA and tributyrin with a similar potency compared with that induced by the vehicle. Left ventricular shortening fraction was significantly higher in the VPA- and tributyrin-treated groups than in the vehicle-treated group. Increased synthesis of atrial natriuretic peptide mRNA after infarction was confirmed by RT-PCR, consistent with the results of immunohistochemistry and Western blot for acetyl histone H4. The beneficial effects of VPA and tributyrin were abolished by theophylline, implicating HDAC as the relevant target. Inhibition of HDAC by VPA or tributyrin can attenuate ventricular remodeling after infarction. This might provide a worthwhile therapeutic target.
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Affiliation(s)
- Tsung-Ming Lee
- Cardiology Section, Department of Medicine, Taipei Medical University and Chi-Mei Medical Center, Taipei, Taiwan
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Lee TM, Lin MS, Chou TF, Chang NC. Additive effects of combined blockade of AT1receptor and HMG-CoA reductase on left ventricular remodeling in infarcted rats. Am J Physiol Heart Circ Physiol 2006; 291:H1281-9. [PMID: 16565312 DOI: 10.1152/ajpheart.00792.2005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both angiotensin receptor antagonists and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been shown to attenuate cardiomyocyte hypertrophy after myocardial infarction. Whether combination treatment may be superior to either drug alone on cardiomyocyte hypertrophy remains unclear. After ligation of the left anterior descending artery, rats were randomized to both, one, or neither of the angiotensin receptor antagonists olmesartan (0.01, 0.1, 1, and 2 mg·kg−1·day−1) and HMG-CoA reductase inhibitor pravastatin (5 mg·kg−1·day−1) for 4 wk. Each drug, when given alone, decreased cardiomyocyte sizes isolated by enzymatic dissociation at the border zone when compared with vehicles. However, compared with either drug alone, combined olmesartan and pravastatin prevent cardiomyocyte hypertrophy to a larger extent, which was further confirmed by downregulation of the left ventricular atrial natriuretic peptide mRNA. The myocardial endothelin-1 levels at the border zone were 6.5-fold higher ( P <0.0001) in the vehicle group compared with the sham group, which can be inhibited after pravastatin administration. Combination treatment significantly attenuated cardiomyocyte hypertrophy in a dose-dependent manner, although tissue endothelin-1 levels remained stable in combination groups of different olmesartan doses. Measurements of the arrhythmic score mirrored those of cardiomyocyte hypertrophy. Dual therapy with pravastatin and olmesartan, which produced an additive reduction in cardiomyocyte hypertrophy and cardiac fibrosis after myocardial infarction through different mechanisms, decreases the propensity of the heart to arrhythmogenesis. Pravastatin administration provided favorable ventricular remodeling, probably through decreased tissue endothelin-1 level. In contrast, olmesartan-related attenuated cardiomyocyte hypertrophy is independent of endothelin-1 pathway.
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MESH Headings
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Angiotensin II Type 1 Receptor Blockers/therapeutic use
- Animals
- Dose-Response Relationship, Drug
- Drug Therapy, Combination
- Endothelin-1/genetics
- Endothelin-1/metabolism
- Gene Expression Regulation/drug effects
- Heart Ventricles/metabolism
- Heart Ventricles/pathology
- Heart Ventricles/physiopathology
- Hemodynamics/drug effects
- Hemodynamics/physiology
- Hydroxymethylglutaryl CoA Reductases/drug effects
- Hydroxymethylglutaryl CoA Reductases/physiology
- Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology
- Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use
- Hypertrophy, Left Ventricular/drug therapy
- Hypertrophy, Left Ventricular/physiopathology
- Hypertrophy, Left Ventricular/prevention & control
- Imidazoles/pharmacology
- Imidazoles/therapeutic use
- Male
- Myocardial Infarction/drug therapy
- Myocardial Infarction/metabolism
- Myocardial Infarction/physiopathology
- Pravastatin/pharmacology
- Pravastatin/therapeutic use
- Rats
- Rats, Wistar
- Receptor, Angiotensin, Type 1/drug effects
- Receptor, Angiotensin, Type 1/physiology
- Tetrazoles/pharmacology
- Tetrazoles/therapeutic use
- Ventricular Remodeling/drug effects
- Ventricular Remodeling/physiology
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Affiliation(s)
- Tsung-Ming Lee
- Cardiology Section, Department of Medicine, Taipei Medical University and National Taiwan University Hospital, 252 Wu-Hsing St, Taipei, Taiwan
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26
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Gosselin H, Béliveau L, Burelle Y, Clément R, Lajoie C, El-Helou V, Calderone A. Disparate regulation of signaling proteins after exercise and myocardial infarction. Med Sci Sports Exerc 2006; 38:455-62. [PMID: 16540832 DOI: 10.1249/01.mss.0000205138.02440.79] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION The signaling proteins extracellular signal-regulated kinase (ERK1/2) and protein kinase B (PKB) were implicated in the development of pathological cardiac hypertrophy. The present study examined whether the progression of physiological eccentric cardiac hypertrophy was associated with ERK1/2 and PKB recruitment. METHODS AND RESULTS Following 1 and 3 wk of voluntary exercise, female Sprague-Dawley rats ran a total distance of 55 +/- 10 and 195 +/- 19 km, respectively. Left ventricular hypertrophy was detected in 3-wk-exercised rats, albeit prepro-ANP protein expression was unchanged. ERK1/2 was not recruited in the left ventricle (LV) of either 1-wk-exercised rats or the hypertrophied LV of 3-wk-exercised rats. In 1-wk-exercised rats, PKB Thr308 and Ser473 phosphorylation were significantly reduced, whereas a selective increase of PKB Ser473 phosphorylation was observed in the hypertrophied LV of 3-wk-exercised rats. In both 1- and 3-wk-exercised rats, an upward electrophoretic mobility band shift of p70 ribosomal S6 kinase (p70 S6K) was detected. In 1-wk post-myocardial-infarcted (MI) female Sprague-Dawley rats, scar formation was associated with increased left ventricular end-diastolic pressure. In the hypertrophied noninfarcted left ventricle (NILV), ERK1/2, p70 S6K, PKB Ser473, and Thr308 phosphorylation were increased. CONCLUSIONS These data support the premise that ERK1/2 and PKB were differentially regulated during the development of eccentric physiological and pathological cardiac hypertrophy. It remains to be determined whether the chronic activation of either ERK1/2 and/or PKB in the NILV of post-MI rats may contribute in part to maladaptive cardiac remodelling.
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Affiliation(s)
- Hugues Gosselin
- Research Centre, Montreal Heart Institute, Montreal, Quebec, Canada
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Hu Q, Wang X, Lee J, Mansoor A, Liu J, Zeng L, Swingen C, Zhang G, Feygin J, Ochiai K, Bransford TL, From AHL, Bache RJ, Zhang J. Profound bioenergetic abnormalities in peri-infarct myocardial regions. Am J Physiol Heart Circ Physiol 2006; 291:H648-57. [PMID: 16582014 DOI: 10.1152/ajpheart.01387.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Regions of myocardial infarct (MI) are surrounded by a border zone (BZ) of normally perfused but dysfunctional myocardium. Although systolic dysfunction has been attributed to elevated wall stress in this region, there is evidence that intrinsic abnormalities of contractile performance exist in BZ myocardium. This study examined whether decreases of high-energy phosphates (HEP) and mitochondrial F(1)F(0)-ATPase (mtATPase) subunits typical of failing myocardium exist in BZ myocardium of compensated postinfarct remodeled hearts. Eight pigs were studied 6 wk after MI was produced by ligation of the left anterior descending coronary artery (LAD) distal to the second diagonal. Animals developed compensated LV remodeling with a decrease of ejection fraction from 54.6 +/- 5.4% to 31 +/- 2.1% (MRI) 5 wk after LAD occlusion. The remote zone (RZ) myocardium demonstrated modest decreases of ATP and mtATPase components. In contrast, BZ myocardium demonstrated profound abnormalities with ATP levels decreased to 42% of normal, and phosphocreatine-to-ATP ratio ((31)P-magnetic resonance spectroscopy) decreased from 2.06 +/- 0.19 in normal hearts to 1.07 +/- 0.10, with decreases in alpha-, beta-, OSCP, and IF(1) subunits of mtATPase, especially in the subendocardium. The reduction of myocardial creatine kinase isoform protein expression was also more severe in the BZ relative to the RZ myocardium. These abnormalities were independent of a change in mitochondrial content because the mitochondrial citrate synthase protein level was not different between the BZ and RZ. This regional heterogeneity of ATP content and expression of key enzymes in ATP production suggests that energetic insufficiency in the peri-infarct region may contribute to the transition from compensated LV remodeling to congestive heart failure.
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Affiliation(s)
- Qingsong Hu
- Cardiovascular Division, Department of Medicine, University of Minnesota Health Science Center, Minneapolis, MN 55455, USA
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Blom AS, Mukherjee R, Pilla JJ, Lowry AS, Yarbrough WM, Mingoia JT, Hendrick JW, Stroud RE, McLean JE, Affuso J, Gorman RC, Gorman JH, Acker MA, Spinale FG. Cardiac support device modifies left ventricular geometry and myocardial structure after myocardial infarction. Circulation 2006; 112:1274-83. [PMID: 16129812 DOI: 10.1161/circulationaha.104.499202] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Whether mechanical restraint of the left ventricle (LV) can influence remodeling after myocardial infarction (MI) remains poorly understood. This study surgically placed a cardiac support device (CSD) over the entire LV and examined LV and myocyte geometry and function after MI. METHODS AND RESULTS Post-MI sheep (35 to 45 kg; MI size, 23+/-2%) were randomized to placement of the CorCap CSD (Acorn Cardiovascular, Inc) (MI+CSD; n=6) or remained untreated (MI only; n=5). Uninstrumented sheep (n=10) served as controls. At 3 months after MI, LV end-diastolic volume (by MRI) was increased in the MI only group compared with controls (98+/-8 versus 43+/-4 mL; P<0.05). In the MI+CSD group, LV end-diastolic volume was lower than MI only values (56+/-7 mL; P<0.05) but remained higher than controls (P<0.05). Isolated LV myocyte shortening velocity was reduced by 35% from control values (P<0.05) in both MI groups. LV myocyte beta-adrenergic response was reduced with MI but normalized in the MI+CSD group. LV myocyte length increased in the MI group and was reduced in the MI+CSD group. Relative collagen content was increased and matrix metalloproteinase-9 was decreased within the MI border region of the CSD group. CONCLUSIONS A CSD beneficially modified LV and myocyte remodeling after MI through both cellular and extracellular mechanisms. These findings provide evidence that nonpharmacological strategies can interrupt adverse LV remodeling after MI.
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Affiliation(s)
- Aaron S Blom
- Department of Surgery, University of Pennsylvania Medical Center, Philadelphia, PA, USA
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Saeed M, Lee RJ, Weber O, Do L, Martin A, Ursell P, Saloner D, Higgins CB. Scarred myocardium imposes additional burden on remote viable myocardium despite a reduction in the extent of area with late contrast MR enhancement. Eur Radiol 2005; 16:827-36. [PMID: 16362420 DOI: 10.1007/s00330-005-0052-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 09/13/2005] [Accepted: 09/29/2005] [Indexed: 10/25/2022]
Abstract
Magnetic resonance imaging (MRI) can simultaneously detect and quantify myocardial dysfunction and shrinkage in contrast-enhanced areas postinfarction. This ability permits the investigation of our hypothesis that transformation of infracted myocardium to scarred tissue imposes additional burdens on peri-infarcted and remote myocardium. Pigs (n = 8) were subjected to reperfused infarction. Gd-DOTA-enhanced inversion recovery gradient echo sequence (IR-GRE) imaging was performed 3 days and 8 weeks postinfarction. Global and regional left ventricular (LV) function was evaluated by cine MRI. Triphenyltetrazolium chloride (TTC) stain was used to delineate infarction while hematoxylin and eosin (H & E) and Masson's trichrome stains were used to characterize remodeled myocardium. Late contrast-enhanced MRIs showed a decrease in the extent of enhanced areas from 17 +/- 2% at 3 days to13 +/- 1% LV mass at 8 weeks. TTC infarction size was 12 +/- 1% LV mass. Cine MRIs showed expansion in dysfunctional area due to unfavorable remodeling, ischemia, or strain. Ejection fraction was reduced in association with increased end-diastolic and end-systolic volumes. Scarred myocardium contained collagen fibers and remodeled thick-walled vessels embedded in collagen. Sequential MRI showed greater LV dysfunction despite the shrinkage in extent of enhanced areas 2 months postinfarction. The integration of late enhancement and cine MRI incorporates anatomical and functional evaluation of remodeled hearts.
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Affiliation(s)
- Maythem Saeed
- Department of Radiology, University of California, San Francisco, 94143-0628, USA.
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Souzeau E, Bélanger S, Picard S, Deschepper CF. Dietary isoflavones during pregnancy and lactation provide cardioprotection to offspring rats in adulthood. Am J Physiol Heart Circ Physiol 2005; 289:H715-21. [PMID: 15778278 DOI: 10.1152/ajpheart.00061.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In adult rats, elongation of cardiac myocytes (CMs) correlates with dilatation (and sometimes dysfunction) of cardiac ventricles. Although sex steroids may constitute one possible factor that affects the dimensions of CMs, studies on their effects in rodents is complicated by the fact that most commercial soy-based diets also contain abundant phytoestrogens. We report that feeding Wistar-Kyoto rat dams during gestation and lactation with a phytoestrogen-rich soy-based diet caused the CMs of their adult offspring to be shorter than in counterparts originating from mothers fed with a phytoestrogen-free casein-based diet. The soy-based diet had no such effects when given to rats after 6 wk of age, and its effects were replicated when supplementing the maternal casein-based diet with the isoflavones daidzein and genistein (the most abundant phytoestrogens in soy-based diets). In contrast to rats whose mothers had been fed with a soy-based diet, the hearts of adult rats raised with a casein-based diet only featured dilated eccentric hypertrophy and progressed toward congestive heart failure when further challenged. Thus the presence of isoflavones in the maternal diet provides cardioprotection to the hearts of their offspring during adulthood.
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Affiliation(s)
- Emmanuelle Souzeau
- Experimental Cardiovascular Biology Research Unit, Institut de Recherches Cliniques de Montréal, 110 Pine Ave. W., Montréal, Quebec, Canada H2W 1R7
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Blom AS, Pilla JJ, Gorman RC, Gorman JH, Mukherjee R, Spinale FG, Acker MA. Infarct Size Reduction and Attenuation of Global Left Ventricular Remodeling with the CorCapTM Cardiac Support Device Following Acute Myocardial Infarction in Sheep. Heart Fail Rev 2005; 10:125-39. [PMID: 16258720 DOI: 10.1007/s10741-005-4640-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Whether mechanical restraint of the left ventricle (LV) can influence remodeling following myocardial infarction (MI) remains poorly understood. The following discussion details three studies examining the effects of surgically placing a cardiac support device (CSD) over the entire epicardial surface, on infarct expansion, global cardiac function and myocyte geometry and function post-MI. METHODS The effects of passive constraint on infarct expansion and global cardiac function/myocardial energetics were investigated in 10 sheep (5 MI only; 5 MI + CSD) using pressure-volume analysis and magnetic resonance imaging (MRI). Additionally, 11 sheep (5 MI only; 6 MI + CSD) were used to study the effects of passive restraint on myocyte geometry and function post-MI, with 10 additional uninstrumented sheep serving as controls. Baseline data was collected followed by the creation of an anterior infarct. 1 week post-infarct the animals underwent a second set of data collection studies followed by placement of the CSD in the experimental groups. Additional data was collected at 2 and 3 months post-MI. The animals in the myocyte function group underwent additional studies immediately following the 3 month time point. RESULTS Infarct expansion was diminished as a result of the CSD. At 1 week post-MI the akinetic area was similar in both groups. At the terminal time-point, the akinetic area in the control group was similar to the 1-week time-point whereas, in the CSD group, the area of akinesis decreased (P = 0.001). A comparison of the two groups at the terminal time-point demonstrates a significantly diminished area of akinesis in the CSD group (P = 0.004). The relative area of akinesis followed a similar pattern. The CSD group also exhibited a decrease in end-diastolic volume (control 110.3 +/- 19.8 mL vs. CSD 67.6 +/- 4.7 mL, P = .006) and an improved ejection fraction (control 15.5% +/- 5.7% vs. CSD 29.46% +/- 4.42%, P = .008) relative to the control group. Myocardial energetics were also enhanced in the CSD group as evidenced by significant improvements in potential energy (control 2,015 +/- 503 mL x mm Hg/beat vs. CSD 885 +/- 220 mL x Hg/beat, P = .006), efficiency (control 39.4% +/- 13.6% vs. CSD 59.8% +/- 8.5%, P = .044), and oxygen consumption (control 0.072 +/- 0.013 mL O(2)/beat vs. CSD 0.052 +/- 0.007 mL O(2)/beat, P = .034). Isolated LV myocyte shortening velocity was reduced by 35% from control values (P < 0.05) in both MI groups. LV myocyte beta-adrenergic response was reduced with MI, but normalized in the MI + CSD group. Relative collagen content was increased and matrix metalloproteinase-9 was decreased within the MI border region of the CSD group. CONCLUSIONS The CorCap cardiac support device retarded infarct expansion, improved global and regional cardiac function and beneficially modified LV and myocyte remodeling post-MI. These findings provide evidence that non-pharmacological strategies can interrupt adverse LV remodeling post-MI.
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Affiliation(s)
- Aaron S Blom
- Department of Surgery, University of Pennsylvania Medical Center, Philadelphia, USA
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Zimmerman SD, Criscione J, Covell JW. Remodeling in myocardium adjacent to an infarction in the pig left ventricle. Am J Physiol Heart Circ Physiol 2004; 287:H2697-704. [PMID: 15319211 DOI: 10.1152/ajpheart.00160.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Changes in the structure of the “normal” ventricular wall adjacent to an infarcted area involve all components of the myocardium (myocytes, fibroblasts and the extracellular matrix, and the coronary vasculature) and their three-dimensional structural relationship. Assessing changes in these components requires tracking material markers in the remodeling tissue over long periods of time with a three-dimensional approach as well as a detailed histological evaluation of the remodeled structure. The purpose of the present study was to examine the hypotheses that changes in the tissue adjacent to an infarct are related to myocyte elongation, myofiber rearrangement, and changes in the laminar architecture of the adjacent tissue. Three weeks after myocardial infarction, noninfarcted tissue adjacent to the infarct remodeled by expansion along the direction of the fibers and in the cross fiber direction. These changes are consistent with myocyte elongation and myofiber rearrangement (slippage), as well as a change in cell shape to a more elliptical cross section with the major axis in the epicardial tangent plane, and indicate that reorientation of fibers either via “cell slippage” or changes in orientation of the laminar structure of the ventricular wall are quantitatively important aspects of the remodeling of the normally perfused myocardium.
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Affiliation(s)
- Scott D Zimmerman
- Dept. of Biomedical Sciences, Southwest Missouri State Univ., 901 S. National Ave., Springfield, MO 65804-0027, USA.
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Swann MH, Nakagawa H, Vanoli E, Lazzara R, Schwartz PJ, Adamson PB. Heterogeneous regional endocardial repolarization is associated with increased risk for ischemia-dependent ventricular fibrillation after myocardial infarction. J Cardiovasc Electrophysiol 2003; 14:873-9. [PMID: 12890052 DOI: 10.1046/j.1540-8167.2003.03100.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
UNLABELLED Repolarization Heterogeneity and Sudden Death Risk. INTRODUCTION The aim of this study was to investigate whether the characteristics of endocardial ventricular repolarization are associated with differential risk for sudden death. Prolonged surface QT interval is associated with increased arrhythmic risk after myocardial infarction (MI), but the underlying mechanism of QT prolongation and its relation to lethal arrhythmias are unclear. METHODS AND RESULTS Ventricular fibrillation (VF) risk was assessed in 12 dogs 1 month after anterior MI during an exercise test coupled with brief circumflex coronary occlusion. Susceptible dogs (n = 5) developed VF during the brief ischemic episode, whereas resistant dogs did not (n = 7). Surface QT interval was measured at rest. Endocardial electroanatomic catheter maps of left ventricular repolarization were obtained in four unique regions identified by echocardiography and compared between groups. Compared to resistant dogs, susceptible dogs were characterized by prolonged surface QT intervals (240 +/- 10 msec vs 222 +/- 7 msec, P = 0.04). In addition, they had lower baroreflex sensitivity (9.7 +/- 1.5 msec/mmHg vs 28 +/- 9.8 msec/mmHg, P < 0.01) and a tachycardic response to acute ischemia suggesting higher propensity for stronger sympathetic reflexes. Surface QT interval prolongation in susceptible dogs was due to a marked heterogeneity of endocardial left ventricular repolarization (239 +/- 42 msec, basal anterior wall vs 197 +/- 35, lateral wall; P < 0.001). Resistant animals had no regional differences in endocardial repolarization. CONCLUSION Sympathetic activation following MI not only produces adverse structural remodeling but also contributes to adverse electrophysiologic remodeling resulting in heterogeneous ventricular repolarization and in a myocardial substrate conducive to lethal reentrant arrhythmias.
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Affiliation(s)
- Michael H Swann
- Physiology and Medicine Cardiology Cardiac Arrhythmia Research Institute WK Warren Medical Research Institute, Oklahoma University Health Sciences Center, Oklahoma City, Oklahoma 73190, USA
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Kim YK, Mankad S, Kim SJ, Takagi G, Tamura T, Gerdes AM, Bishop SP, Kramer CM. Adding angiotensin II type 1 receptor blockade to angiotensin-converting enzyme inhibition limits myocyte remodeling after myocardial infarction. J Card Fail 2003; 9:238-45. [PMID: 12815575 DOI: 10.1054/jcaf.2003.32] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Adding angiotensin II type 1 receptor blockade (ARB) to angiotensin-converting enzyme inhibition (ACEI) further attenuates left ventricular (LV) remodeling in an ovine model of myocardial infarction (MI). We hypothesized that combined therapy with ACEI and ARB (CT) would be additive in the limitation of the myocyte hypertrophy and dysfunction that occurs in untreated adjacent noninfarcted regions during remodeling. METHODS AND RESULTS Nineteen sheep underwent coronary ligation to create a moderate-sized anteroapical infarction. Post-MI day 2, sheep were randomized to therapy with ramipril (ACEI, n = 5) or ramipril plus losartan (CT, n = 6) or none (untreated, n = 8). Infarct size was similar between groups. At 8 weeks post-MI, myocytes were isolated from regions adjacent to and remote from the infarct to measure morphometric indices (cell volume, length, cross-sectional area, width) and parameters of contraction (% shortening and -dL/dt, rate of shortening) and relaxation (+dL/dt [rate of relengthening] and TR 70% [time for 70% relengthening]). Volume % collagen was measured from adjacent and remote regions. Adjacent myocyte volume was different between groups (2.5 +/- 0.1 x 10(4) microm(3) in CT, 3.0 +/- 0.4 x 10(4) microm(3) in ACEI, 3.5 +/- 0.2 x 10(4) microm(3) in untreated, analysis of variance [ANOVA] P =.001) as was length (158 +/- 4 microm, 161 +/- 9 microm, 189 +/- 8 microm, respectively, ANOVA P <.001). Adjacent cell volume and length in CT were lower than untreated (P <.05). Percent shortening and -dL/dt of isolated adjacent myocytes were improved with both ACEI (7.9 +/- 0.3%, -131 +/- 6 microm/sec, P <.05) and CT (7.7 +/- 0.3%, -144 +/- 8 microm/sec, P <.05) compared with no therapy (6.4 +/- 0.4%, -104 +/- 7 microm/sec), as was both +dL/dt and TR 70%. No between-group difference in volume % collagen was found in adjacent or remote regions. CONCLUSION Compared with ACEI alone, the addition of ARB further limits adjacent noninfarcted myocyte hypertrophy during post-MI LV remodeling. Both ACEI alone and CT preserve isolated unloaded myocyte function, but neither significantly reduce interstitial collagen. The additional benefit of ARB on regional and global function in vivo may also be due to other factors including regional load.
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Affiliation(s)
- Young-Kwon Kim
- Department of Cell Biology and Molecular Medicine, UMDNJ-New Jersey Medical School, New Jersey, USA
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Boutin-Ganache I, Picard S, Deschepper CF. Distinct gene-sex interactions regulate adult rat cardiomyocyte width and length independently. Physiol Genomics 2002; 12:61-7. [PMID: 12419859 DOI: 10.1152/physiolgenomics.00121.2002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Wistar-Kyoto (WKY) and WKY-derived hyperactive (WKHA) rats are two genetically-related inbred strains of rats that are both normotensive yet exhibit differences in left ventricular mass (LVM). We had shown previously that cardiomyocytes from male WKHA are wider than that of male WKY, and that there was genetic linkage between LVM and a locus on chromosome 5 (RNO5) in the male progeny of a F2 WKHA/WKY cross. We show here that cardiomyocyte width is linked to the same RNO5 locus in male reciprocal congenic rats derived from WKHA and WKY. Contrary to males, we found no genetic linkage between LVM and the RNO5 locus in female rats. However, ventricular hypertrophy in females might be of a different nature, because cardiomyocytes from female WKHA were shorter than their WKY counterparts (with no difference in width). The RNO5 locus contains that of the natriuretic peptide precursor A (Nppa) gene. In male congenic rats, changes in cardiomyocyte width always correlated with reciprocal changes in the LV concentration of atrial natriuretic factor (ANF, i.e., the peptide product of Nppa). Taken together with other functional data, the small size of the RNO5 locus (approximately 63 cR) increased the likelihood that both cardiomyocyte width and LV ANF concentration could be linked to only one gene (possibly Nppa) in male rats. Moreover, our results support the notion that genes and sex interact to regulate cardiomyocyte width and length independently from one another.
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Affiliation(s)
- I Boutin-Ganache
- Experimental Cardiovascular Biology Research Unit, Institut de Recherche Cliniques de Montréal, Montreal, Quebec, Canada H2W 1R7
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Saeed M, Watzinger N, Krombach GA, Lund GK, Wendland MF, Chujo M, Higgins CB. Left ventricular remodeling after infarction: sequential MR imaging with oral nicorandil therapy in rat model. Radiology 2002; 224:830-7. [PMID: 12202722 DOI: 10.1148/radiol.2243011372] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To use magnetic resonance (MR) imaging in quantification of the short- and long-term effects of therapy with orally administered nicorandil on left ventricular (LV) geometry and function independent of infarction size. MATERIALS AND METHODS Forty-six rats were subjected to reperfused infarction and randomly divided into two groups. Group 1 rats (n = 21) were treated with nicorandil (3 mg/kg/day in drinking water) for 4 days before infarction and 8 weeks after infarction (hereafter, the nicorandil group). Group 2 rats (n = 25) received tap water for the same period and served as the control group. Mesoporphyrin- (as a necrosis-specific agent) enhanced MR imaging was used to define necrotic myocardium on day 2 after infarction in all 46 animals. Contrast material-enhanced MR images showed large but identical infarction size in 11 control and 11 nicorandil rats. Only these 22 rats underwent repeat MR imaging at 8 weeks after infarction. The following variables were measured: LV volumes, ejection fraction, mass, wall thickness, and infarction size. Student t test and analysis of variance for repeated measurements were used for statistical analysis. RESULTS The size of the necrotic region on mesoporphyrin-enhanced MR images was 39% +/- 3 of the size of the left ventricle in the control group and 41% +/- 2 in the nicorandil group (difference not significant, unpaired Student t test). Pretreatment with nicorandil for 6 days before imaging did not reduce LV dilation or improve function compared with those in control animals with identical infarction size. Eight weeks after infarction, control animals showed deterioration in LV function, wall thinning, and gradient in regional dysfunction (analysis of variance test). Nicorandil produced significant salutary effects on LV ejection fraction (37% +/- 3 in the nicorandil group vs 24% +/- 3 in the control group), end-diastolic volume (0.53 mL +/- 0.03 vs 0.65 mL +/- 0.04), end-systolic volume (0.36 mL +/- 0.03 vs 0.49 mL +/- 0.05), LV wall thickening in remote noninfarcted myocardium (28% +/- 2 vs 19% +/- 1), and a rim of infarction (16% +/- 2 vs 8% +/- 1) (P <.05 for all parameters). The increase in LV mass was reduced in the nicorandil group (0.73 g +/- 0.03) compared with that in the control group (0.89 g +/- 0.04) (P <.05). CONCLUSION In animals studied longitudinally, MR imaging demonstrated the deleterious changes in LV geometry and function in the period after infarction and the salutary effects of medical therapy.
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Affiliation(s)
- Maythem Saeed
- Department of Radiology, University of California, San Francisco, 505 Parnassus Ave, Rm L-308, 94143-0628, USA.
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Epstein FH, Yang Z, Gilson WD, Berr SS, Kramer CM, French BA. MR tagging early after myocardial infarction in mice demonstrates contractile dysfunction in adjacent and remote regions. Magn Reson Med 2002; 48:399-403. [PMID: 12210951 DOI: 10.1002/mrm.10210] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The purpose of this study was to use MR myocardial tagging to assess regional cardiac function after myocardial infarction (MI) in mice. Eight mice were imaged before and 1 day after MI. MRI included cine imaging, myocardial tagging, and contrast-enhanced imaging. Regional percent circumferential shortening (%CS) was measured from the tagged images, and the region of hyperenhancement on the contrast-enhanced images was used to determine the infarcted, adjacent, and remote zones. Ejection fraction (EF) fell from 59% +/- 6% at baseline to 32% +/- 6% after MI (P < 0.01). At baseline, %CS was 14.5% +/- 3.4%. After MI, %CS was 0.7% +/- 4.4% in the infarcted zone, 7.4% +/- 4.4% in the adjacent zone, and 11.8% +/- 4.2% in the remote zone. %CS was statistically different for all comparisons between the infarcted, adjacent, remote, and baseline groups (P < 0.01). MR tagging can detect regional differences in myocardial function post-MI in mice.
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Yang Z, Bove CM, French BA, Epstein FH, Berr SS, DiMaria JM, Gibson JJ, Carey RM, Kramer CM. Angiotensin II type 2 receptor overexpression preserves left ventricular function after myocardial infarction. Circulation 2002; 106:106-11. [PMID: 12093778 DOI: 10.1161/01.cir.0000020014.14176.6d] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The role of the angiotensin II type 2 receptor (AT2-R) in left ventricular (LV) remodeling may depend on the underlying stimulus. We hypothesized that cardiac AT2-R overexpression in transgenic (TG) mice would attenuate remodeling after myocardial infarction (MI). METHODS AND RESULTS Ten wild-type (WT) C57BL/6 mice and 12 TG mice that overexpress the AT2-R in the heart were studied by cardiac MRI at baseline and days 1, 7, and 28 post-MI induced by 1 hour of occlusion of the LAD followed by reperfusion. Short-axis imaging from apex to base was used to determine LV mass index, end-diastolic and end-systolic volume indices (EDVI, ESVI), regional wall thickness and thickening, and ejection fraction (EF). Gadolinium-DTPA was infused 20 minutes before day 1 imaging to assess infarct size. At baseline, heart rate, blood pressure, LV mass index, and EDVI were similar between groups. Baseline ESVI was lower (0.20+/-0.07 versus 0.45+/-0.15 microL/g, P<0.001) and EF higher (82.3+/-4.9% versus 67.7+/-5.3%, P<0.001) in TG than WT. Infarct size was similar (36.6+/-7.2% in WT, 34.0+/-7.8% in TG, P=NS). When controlled for baseline differences, ESVI was significantly less and EF significantly higher at all time points in TG versus WT. At day 28, ESVI was 1.05+/-0.32 microL/g in TG and 1.63+/-0.41 microL/g in WT, P<0.03, and EF was 47.3+/-5.8% versus 34.1+/-9.2%, P<0.003, respectively. Regional wall thickness and thickening were greater in TG both at baseline and at day 28. At day 28, blood pressure and LV dP/dt were higher in TG. CONCLUSIONS Cardiac AT2-R overexpression improves LV systolic function at baseline and preserves function during post-MI remodeling.
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Affiliation(s)
- Zequan Yang
- Department of Medicine and the Cardiovascular Research Center, University of Virginia Health System, Charlottesville 22908, USA
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Mankad S, d'Amato TA, Reichek N, McGregor WE, Lin J, Singh D, Rogers WJ, Kramer CM. Combined angiotensin II receptor antagonism and angiotensin-converting enzyme inhibition further attenuates postinfarction left ventricular remodeling. Circulation 2001; 103:2845-50. [PMID: 11401943 DOI: 10.1161/01.cir.103.23.2845] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND ACE inhibition (ACEI) attenuates post-myocardial infarction (MI) LV remodeling, but the effects of angiotensin II type 1 receptor (AT(1)) antagonism alone or in combination with ACEI are unclear. Accordingly, we investigated the effects of AT(1) antagonism, ACEI, and their combination in a well-characterized ovine postinfarction model. METHODS AND RESULTS Beginning 2 days after transmural anteroapical MI, 62 sheep were treated with 1 of 5 treatment regimens: no therapy (control, n=12), standard-dose ACEI (sACEI; ramipril 10 mg/d, n=14), high-dose ACEI (hACEI; ramipril 20 mg/d, n=8), AT(1) blockade (losartan 50 mg/d, n=13), and combination therapy with sACEI+AT(1) blockade (CT; ramipril 10 mg/d+losartan 50 mg/d, n=15). MRI was performed before and 8 weeks after MI to quantify changes in LV end-diastolic and end-systolic volume indices (DeltaEDVI, DeltaESVI) and ejection fraction (DeltaEF). Change in regional percent intramyocardial circumferential shortening in noninfarcted segments adjacent to the infarct (Adj Delta%S) was measured by tagged MRI. CT resulted in the most marked blunting of LV remodeling: DeltaESVI (+1.0+/-0.4, +0.7+/-0.4, +0.6+/-0.3, +0.9+/-0.5, and +0.4+/-0.2* mL/kg); DeltaEDVI (+0.9+/-0.4, +0.7+/-0.5, +0.6+/-0.5, +0.9+/-0.5, and +0.4+/-0.3 mL/kg); DeltaEF (-24+/-7, -18+/-6, -14+/-7, -18+/-10, and -11+/-9* %); and Adj Delta%S (-8+/-4, -7+/-3, -5+/-3, -5+/-3, and -2+/-3* %) for Control, sACEI, hACEI, AT(1) blockade, and CT, respectively (*P<0.04 versus sACEI, AT(1) blockade, and control; P<0.05 versus control; P<0.002 versus AT(1) blockade and control). EDVI and ESVI at 8 weeks after MI were smallest with CT (P<0.02 versus all). CONCLUSIONS Combination therapy with sACEI+AT(1) blockade shows promise in attenuating postinfarction LV remodeling but was not clearly superior to hACEI in the present study.
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MESH Headings
- Angiotensin Receptor Antagonists
- Angiotensin-Converting Enzyme Inhibitors/pharmacology
- Animals
- Blood Pressure/drug effects
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Synergism
- Drug Therapy, Combination
- Electrocardiography
- Female
- Image Processing, Computer-Assisted
- Losartan/pharmacology
- Magnetic Resonance Imaging, Cine
- Myocardial Infarction/diagnosis
- Myocardial Infarction/drug therapy
- Myocardial Infarction/physiopathology
- Myocardium/metabolism
- Myocardium/pathology
- Ramipril/pharmacology
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Sheep
- Stroke Volume/drug effects
- Systole
- Ventricular Function, Left/drug effects
- Ventricular Remodeling/drug effects
- Ventricular Remodeling/physiology
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Affiliation(s)
- S Mankad
- Division of Cardiology, Department of Medicine, Allegheny General Hospital, Pittsburgh, PA 15212, USA.
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Prahash AJ, Gupta S, Anand IS. Myocyte response to beta-adrenergic stimulation is preserved in the noninfarcted myocardium of globally dysfunctional rat hearts after myocardial infarction. Circulation 2000; 102:1840-6. [PMID: 11023941 DOI: 10.1161/01.cir.102.15.1840] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cellular mechanisms underlying the diminished inotropic response of remodeled hearts after myocardial infarction (MI) remain unclear. METHODS AND RESULTS Left ventricular (LV) remodeling and function were assessed by 2D echocardiography and isolated perfused heart studies in 6-week post-MI and sham-operated rats. LV myocytes from sham and noninfarcted MI hearts were used for morphometric and functional studies. Beta-adrenergic receptor (beta-AR) agonist isoproterenol (ISO)-induced contractile response was measured in isolated hearts. The effects of ISO and forskolin on contractile function and calcium transients of isolated myocytes were recorded. ISO-induced cAMP generation was compared in sham and MI myocytes. beta-AR density was measured by radioligand binding. MI hearts were remodeled (LV diameter 8.5+/-0.3 versus 5.7+/-0.3 mm, P:<0.001) and showed global (% fractional shortening 19.1+/-2.5 versus 55.3+/-2.2, P:<0.01) and regional contractile dysfunction of noninfarcted myocardium (% systolic posterior wall thickening 37+/-4 versus 62+/-10, P:<0.01). Isolated heart function (LV developed pressure 58+/-2 versus 72+/-3 mm Hg, P:=0.004) and ISO concentration response were reduced in MI hearts. Myocytes from the noninfarcted LV were structurally remodeled (32% longer and 18% wider), but their contractile response and intracellular calcium kinetics to ISO and forskolin were not diminished. beta-AR receptor density (B(max) 24+/-1.5 versus 22.4+/-1.6 fmol/mg protein) and beta-AR agonist-stimulated cAMP were similar in both groups. CONCLUSIONS Isolated myocytes from the remodeled and dysfunctional myocardium are structurally modified but contract normally under basal conditions and in response to beta-AR stimulation. beta-AR density is preserved in remodeled myocytes. Nonmyocyte factors may be more important in the genesis of contractile dysfunction in the remodeled rat heart up to 6 weeks after MI.
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Affiliation(s)
- A J Prahash
- Department of Medicine and Division of Cardiology, University of Minnesota and VA Medical Center, Minneapolis, MN 55417, USA
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Waring WS. Early initiation of ACE inhibitor treatment after acute myocardial infarction--a missed therapeutic opportunity? J Renin Angiotensin Aldosterone Syst 2000; 1:245-51. [PMID: 11881032 DOI: 10.3317/jraas.2000.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Kramer CM, Nicol PD, Rogers WJ, Seibel PS, Park CS, Reichek N. Beta-blockade improves adjacent regional sympathetic innervation during postinfarction remodeling. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:H1429-34. [PMID: 10516178 DOI: 10.1152/ajpheart.1999.277.4.h1429] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of beta-blockade on left ventricular (LV) remodeling, when added to angiotensin-converting enzyme inhibition (ACEI) after anterior myocardial infarction (MI), is incompletely understood. On day 2 after coronary ligation-induced anteroapical infarction, 17 sheep were randomized to ramipril (ACEI, n = 8) or ramipril and metoprolol (ACEI-beta, n = 9). Magnetic resonance imaging was performed before and 8 wk after MI to measure changes in LV end-diastolic, end-systolic, and stroke volume indexes, LV mass index, ejection fraction (EF), and regional percent intramyocardial circumferential shortening. (123)I-labeled m-iodobenzylguanidine (MIBG) and fluorescent microspheres before and after adenosine were infused before death at 8 wk post-MI for quantitation of sympathetic innervation, blood flow, and blood flow reserve in adjacent and remote noninfarcted regions. Infarct size, regional blood flow, blood flow reserve, and the increase in LV mass and LV end-diastolic and end-systolic volume indexes were similar between groups. However, EF fell less over the 8-wk study period in the ACEI-beta group (-13 +/- 11 vs. -22 +/- 4% in ACEI, P < 0.05). The ratio of adjacent to remote region (123)I-MIBG uptake was greater in ACEI-beta animals than in the ACEI group (0.93 +/- 0.06 vs. 0.86 +/- 0.07, P < 0.04). When added to ACE inhibition after transmural anteroapical MI, beta-blockade improves EF and adjacent regional sympathetic innervation but does not alter LV size.
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Affiliation(s)
- C M Kramer
- Division of Cardiology, Department of Medicine, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA
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Solomon SD, Greaves SC, Rayan M, Finn P, Pfeffer MA, Pfeffer JM. Temporal dissociation of left ventricular function and remodeling following experimental myocardial infarction in rats. J Card Fail 1999; 5:213-23. [PMID: 10496194 DOI: 10.1016/s1071-9164(99)90006-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Left ventricular function early after myocardial infarction (MI) predicts subsequent clinical outcome. Nevertheless, the relationship between early changes in left ventricular function and subsequent left ventricular remodeling has not been well defined. METHODS AND RESULTS To explore the temporal relationship between left ventricular function and remodeling after MI, rats (n = 63) underwent coronary artery ligation with and without reperfusion at 45 or 180 minutes or a sham operation. All animals were followed up by serial echocardiography preligation; 4, 24, and 48 hours; and 1, 2, 3, 4, 6, and 9 weeks after MI. Measures of global left ventricular size and function and regional wall motion were obtained at physiological heart rates. Histological infarct sizes (range, 0% to 52%) were determined in all animals. Within 4 hours of MI, fractional area change (FAC) decreased dramatically in association with an increase in left ventricular systolic cavity area, whereas diastolic area increased more gradually. Early FAC was related to infarct size (r = -0.82; P < .000), predicted the extent of left ventricular enlargement (P = .0001), and remained depressed throughout the duration of follow-up. Regional wall motion excursion and systolic wall thickness decreased in the infarcted and noninfarcted regions in animals with large infarctions. CONCLUSIONS The rate of left ventricular dilatation after MI in rats is proportional to initial left ventricular function, although left ventricular function remains relatively constant as the ventricle progressively enlarges. Regional myocardial function after a large MI is abnormal in noninfarcted as well as infarcted regions.
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Affiliation(s)
- S D Solomon
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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