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Combémorel N, Cavell N, Tyser RCV. Early heart development: examining the dynamics of function-form emergence. Biochem Soc Trans 2024:BST20230546. [PMID: 38979619 DOI: 10.1042/bst20230546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 07/10/2024]
Abstract
During early embryonic development, the heart undergoes a remarkable and complex transformation, acquiring its iconic four-chamber structure whilst concomitantly contracting to maintain its essential function. The emergence of cardiac form and function involves intricate interplays between molecular, cellular, and biomechanical events, unfolding with precision in both space and time. The dynamic morphological remodelling of the developing heart renders it particularly vulnerable to congenital defects, with heart malformations being the most common type of congenital birth defect (∼35% of all congenital birth defects). This mini-review aims to give an overview of the morphogenetic processes which govern early heart formation as well as the dynamics and mechanisms of early cardiac function. Moreover, we aim to highlight some of the interplay between these two processes and discuss how recent findings and emerging techniques/models offer promising avenues for future exploration. In summary, the developing heart is an exciting model to gain fundamental insight into the dynamic relationship between form and function, which will augment our understanding of cardiac congenital defects and provide a blueprint for potential therapeutic strategies to treat disease.
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Affiliation(s)
- Noémie Combémorel
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Cambridge CB2 0AW, U.K
| | - Natasha Cavell
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Cambridge CB2 0AW, U.K
| | - Richard C V Tyser
- Cambridge Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Cambridge CB2 0AW, U.K
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Bayer CL, Wlodarczyk BJ, Finnell RH, Emelianov SY. Ultrasound-guided spectral photoacoustic imaging of hemoglobin oxygenation during development. BIOMEDICAL OPTICS EXPRESS 2017; 8:757-763. [PMID: 28270982 PMCID: PMC5330552 DOI: 10.1364/boe.8.000757] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/19/2016] [Accepted: 12/23/2016] [Indexed: 05/06/2023]
Abstract
Few technologies are capable of imaging in vivo function during development. In this study, we have implemented spectral photoacoustic imaging to estimate tissue oxygenation longitudinally in pregnant mice. We used the spectral photoacoustic signal to estimate hemoglobin oxygen saturation within intact, in vivo mouse concepti from developmental day (E) 8.5 to E16.5-a first step towards functional imaging of the maternal-fetal environment. Future work will apply these methods to compare longitudinal functional changes during normal vs abnormal development of embryos, fetuses, and placentas.
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Affiliation(s)
- Carolyn L. Bayer
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Currently with the Department of Biomedical Engineering, Tulane University, 500 Lindy Boggs Center, New Orleans, LA 70118, USA
| | - Bogdan J. Wlodarczyk
- Dell Pediatric Research Institute, Department of Nutritional Sciences, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA
| | - Richard H. Finnell
- Dell Pediatric Research Institute, Department of Nutritional Sciences, The University of Texas at Austin, 1400 Barbara Jordan Blvd, Austin, TX 78723, USA
| | - Stanislav Y. Emelianov
- Department of Biomedical Engineering, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
- Currently with the School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, Atlanta, GA 30332, USA
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Yap CH, Liu X, Pekkan K. Characterization of the vessel geometry, flow mechanics and wall shear stress in the great arteries of wildtype prenatal mouse. PLoS One 2014; 9:e86878. [PMID: 24475188 PMCID: PMC3903591 DOI: 10.1371/journal.pone.0086878] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/18/2013] [Indexed: 12/16/2022] Open
Abstract
Introduction Abnormal fluid mechanical environment in the pre-natal cardiovascular system is hypothesized to play a significant role in causing structural heart malformations. It is thus important to improve our understanding of the prenatal cardiovascular fluid mechanical environment at multiple developmental time-points and vascular morphologies. We present such a study on fetal great arteries on the wildtype mouse from embryonic day 14.5 (E14.5) to near-term (E18.5). Methods Ultrasound bio-microscopy (UBM) was used to measure blood velocity of the great arteries. Subsequently, specimens were cryo-embedded and sectioned using episcopic fluorescent image capture (EFIC) to obtain high-resolution 2D serial image stacks, which were used for 3D reconstructions and quantitative measurement of great artery and aortic arch dimensions. EFIC and UBM data were input into subject-specific computational fluid dynamics (CFD) for modeling hemodynamics. Results In normal mouse fetuses between E14.5–18.5, ultrasound imaging showed gradual but statistically significant increase in blood velocity in the aorta, pulmonary trunk (with the ductus arteriosus), and descending aorta. Measurement by EFIC imaging displayed a similar increase in cross sectional area of these vessels. However, CFD modeling showed great artery average wall shear stress and wall shear rate remain relatively constant with age and with vessel size, indicating that hemodynamic shear had a relative constancy over gestational period considered here. Conclusion Our EFIC-UBM-CFD method allowed reasonably detailed characterization of fetal mouse vascular geometry and fluid mechanics. Our results suggest that a homeostatic mechanism for restoring vascular wall shear magnitudes may exist during normal embryonic development. We speculate that this mechanism regulates the growth of the great vessels.
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Affiliation(s)
- Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore
| | - Xiaoqin Liu
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Kim AJ, Francis R, Liu X, Devine WA, Ramirez R, Anderton SJ, Wong LY, Faruque F, Gabriel GC, Chung W, Leatherbury L, Tobita K, Lo CW. Microcomputed tomography provides high accuracy congenital heart disease diagnosis in neonatal and fetal mice. Circ Cardiovasc Imaging 2013; 6:551-9. [PMID: 23759365 DOI: 10.1161/circimaging.113.000279] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Mice are well suited for modeling human congenital heart disease (CHD), given their 4-chamber cardiac anatomy. However, mice with CHD invariably die prenatally/neonatally, causing CHD phenotypes to be missed. Therefore, we investigated the efficacy of noninvasive microcomputed tomography (micro-CT) to screen for CHD in stillborn/fetal mice. These studies were performed using chemically mutagenized mice expected to be enriched for birth defects, including CHD. METHODS AND RESULTS Stillborn/fetal mice obtained from the breeding of N-ethyl-N-nitrosourea mutagenized mice were formalin-fixed and stained with iodine, then micro-CT scanned. Those diagnosed with CHD and some CHD-negative pups were necropsied. A subset of these were further analyzed by histopathology to confirm the CHD/no-CHD diagnosis. Micro-CT scanning of 2105 fetal/newborn mice revealed an abundance of ventricular septal defects (n=307). Overall, we observed an accuracy of 89.8% for ventricular septal defect diagnosis. Outflow tract anomalies identified by micro-CT included double outlet right ventricle (n=36), transposition of the great arteries (n=14), and persistent truncus arteriosus (n=3). These were diagnosed with a 97.4% accuracy. Aortic arch anomalies also were readily detected with an overall 99.6% accuracy. This included right aortic arch (n=28) and coarctation/interrupted aortic arch (n=12). Also detected by micro-CT were atrioventricular septal defects (n=22), tricuspid hypoplasia/atresia (n=13), and coronary artery fistulas (n=16). They yielded accuracies of 98.9%, 100%, and 97.8%, respectively. CONCLUSIONS Contrast enhanced micro-CT imaging in neonatal/fetal mice can reliably detect a wide spectrum of CHD. We conclude that micro-CT imaging can be used for routine rapid assessments of structural heart defects in fetal/newborn mice.
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Affiliation(s)
- Andrew J Kim
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201, USA
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Abstract
Transgenic mice displaying abnormalities in cardiac development and function represent a powerful tool for the understanding the molecular mechanisms underlying both normal cardiovascular function and the pathophysiological basis of human cardiovascular disease. Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. In order to study the role of genetic or pharmacologic alterations in the early development of cardiac function, ultrasound imaging of the live fetus has become an important tool for early recognition of abnormalities and longitudinal follow-up. Noninvasive ultrasound imaging is an ideal method for detecting and studying congenital malformations and the impact on cardiac function prior to death. It allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies. Until recently, imaging of fetal mouse hearts frequently involved invasive methods. The fetus had to be sacrificed to perform magnetic resonance microscopy and electron microscopy or surgically delivered for transillumination microscopy. An application of high-frequency probes with conventional 2-D and pulsed-wave Doppler imaging has been shown to provide measurements of cardiac contraction and heart rates during embryonic development with databases of normal developmental changes now available. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. High-frequency ultrasound imaging of the fetus has improved 2-D resolution and can provide excellent information on the early development of cardiac structures.
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Affiliation(s)
- Gene H Kim
- Department of Medicine, Section of Cardiology, Institute for Cardiovascular Research, University of Chicago, USA.
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Purssell E, Weston AD, Thomson JJ, Swanson TA, Brown NA, Ozolinš TR. Noninvasive high-resolution ultrasound reveals structural and functional deficits in dimethadione-exposed fetal rat hearts in utero. ACTA ACUST UNITED AC 2011; 95:35-46. [DOI: 10.1002/bdrb.20339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 09/09/2011] [Accepted: 09/12/2011] [Indexed: 11/05/2022]
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Tobita K, Liu X, Lo CW. Imaging modalities to assess structural birth defects in mutant mouse models. ACTA ACUST UNITED AC 2010; 90:176-84. [PMID: 20860057 DOI: 10.1002/bdrc.20187] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Assessment of structural birth defects (SBDs) in animal models usually entails conducting detailed necropsy for anatomical defects followed by histological analysis for tissue defects. Recent advances in new imaging technologies have provided the means for rapid phenotyping of SBDs, such as using ultra-high frequency ultrasound biomicroscopy, optical coherence tomography, micro-CT, and micro-MRI. These imaging modalities allow the detailed assessment of organ/tissue structure, and with ultrasound biomicroscopy, structure and function of the cardiovascular system also can be assessed noninvasively, allowing the longitudinal tracking of the fetus in utero. In this review, we briefly discuss the application of these state-of-the-art imaging technologies for phenotyping of SBDs in rodent embryos and fetuses, showing how these imaging modalities may be used for the detection of a wide variety of SBDs.
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Affiliation(s)
- Kimimasa Tobita
- Department of Developmental Biology, University of Pittsburgh, Pennsylvania 15224, USA.
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Dinkel J, Bartling SH, Kuntz J, Grasruck M, Kopp-Schneider A, Iwasaki M, Dimmeler S, Gupta R, Semmler W, Kauczor HU, Kiessling F. Intrinsic gating for small-animal computed tomography: a robust ECG-less paradigm for deriving cardiac phase information and functional imaging. Circ Cardiovasc Imaging 2009; 1:235-43. [PMID: 19808548 DOI: 10.1161/circimaging.108.784702] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND A projection-based method of intrinsic cardiac gating in small-animal computed tomography imaging is presented. METHODS AND RESULTS In this method, which operates without external ECG monitoring, the gating reference signal is derived from the raw data of the computed tomography projections. After filtering, the derived gating reference signal is used to rearrange the projection images retrospectively into data sets representing different time points in the cardiac cycle during expiration. These time-stamped projection images are then used for tomographic reconstruction of different phases of the cardiac cycle. Intrinsic gating was evaluated in mice and rats and compared with extrinsic retrospective gating. An excellent agreement was achieved between ECG-derived gating signal and self-gating signal (coverage probability for a difference between the 2 measurements to be less than 5 ms was 89.2% in mice and 85.9% in rats). Functional parameters (ventricular volumes and ejection fraction) obtained from the intrinsic and the extrinsic data sets were not significantly different. The ease of use and reliability of intrinsic gating were demonstrated via a chemical stress test on 2 mice, in which the system performed flawlessly despite an increased heart rate. Because of intrinsic gating, the image quality was improved to the extent that even the coronary arteries of mice could be visualized in vivo despite a heart rate approaching 430 bpm. Feasibility of intrinsic gating for functional imaging and assessment of cardiac wall motion abnormalities was successfully tested in a mouse model of myocardial infarction. CONCLUSIONS Our results demonstrate that self-gating using advanced software postprocessing of projection data promises to be a valuable tool for rodent computed tomography imaging and renders ECG gating with external electrodes superfluous.
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Affiliation(s)
- Julien Dinkel
- Department of Radiology, German Cancer Research Center, Heidelberg, Germany.
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Corrigan N, Brazil DP, Auliffe FM. High-frequency ultrasound assessment of the murine heart from embryo through to juvenile. Reprod Sci 2009; 17:147-57. [PMID: 19843878 DOI: 10.1177/1933719109348923] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AIM The aim of this study is to assess the murine heart of normal embryos, neonates, and juveniles using high-frequency ultrasound. METHODS Diastolic function was measured with E/A ratio (E wave velocity/A wave velocity) and isovolumetric relaxation time (IRT), systolic function with isovolumetric contraction time (ICT), percentage fractional shortening (FS %), percentage ejection fraction (EF %). Global cardiac performance was quantified using myocardial performance index (MPI). RESULTS Isovolumetric relaxation time remained stable from E10.5 to 3 weeks. Systolic function (ICT) improved with gestation and remained stable from E18.5 onward. Myocardial performance index showed improvement in embryonic life (0.82- 0.63) and then stabilized from 1 to 3 week (0.60-0.58). Percentage ejection fraction remained high during gestation (77%-69%) and then decreased from the neonate to juvenile (68%-51%). CONCLUSION The ultrasound biomicroscope allows for noninvasive in-depth assessment of cardiac function of embryos and pups. Detailed physiological and functional cardiac function readouts can be obtained, which is invaluable for comparison to mouse models of disease.
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Affiliation(s)
- Niamh Corrigan
- UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland
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Spurney CF, Lo CW, Leatherbury L. Fetal Mouse Imaging Using Echocardiography: A Review of Current Technology. Echocardiography 2006; 23:891-9. [PMID: 17069613 DOI: 10.1111/j.1540-8175.2006.00335.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Advances in genetic research have led to the need for phenotypic analysis of small animal models. However, often these genetic alterations, especially when affecting the cardiovascular system, can result in fetal or perinatal death. Noninvasive ultrasound imaging is an ideal method for detecting and studying such congenital malformations, as it allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies. Two platforms for fetal mouse echocardiography exist, the clinical systems with 15-MHz phased array transducers and research systems with 20-55-MHz mechanical transducers. The clinical ultrasound system has limited two-dimensional (2D) resolution (axial resolution of 440 microm), but the availability of color and spectral Doppler allows quick interrogations of blood flows, facilitating the detection of structural abnormalities. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. In comparison, the research biomicroscope system has significantly improved 2D resolution (axial resolution of 28 microm). Spectral Doppler imaging is also available, but in the absence of color Doppler, imaging times are increased and the detection of flow abnormalities is more difficult. M-mode imaging is available and equivalent to the clinical ultrasound system. Overall, the research system, given its higher 2D resolution, is best suited for in-depth analysis of mouse fetal cardiovascular structure and function, while the clinical ultrasound systems, equipped with phase array transducers and color Doppler imaging, are ideal for high-throughput fetal cardiovascular screens.
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Affiliation(s)
- Christopher F Spurney
- Division of Cardiology, Children's National Medical Center, Washington, DC 20010, USA.
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Abstract
Progress has been rapid in the elucidation of genes responsible for cardiac development. Strategies to ascertain phenotypes, however, have lagged behind advances in genomics, particularly in the in vivo mouse embryo, considered a model organism for mammalian development, and for human development and disease. Over the past several years, our laboratory and others have pioneered a variety of ultrasound biomicroscopy (UBM)-Doppler approaches to study in vivo development in both normal and mutant mouse embryos. This state-of-the-art review will discuss the development and potential of ultrasound biomicroscopy as a tool for the in vivo imaging and phenotyping of both cardiac and non-cardiac organ systems in the early developing mouse. Broad, long-term research objectives are to define living structure-function relationships during critical periods of mammalian morphogenesis.
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Affiliation(s)
- Colin Kit Lun Phoon
- Pediatric Cardiology Program, New York University School of Medicine, New York 10016, USA.
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12
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Ji RP, Phoon CKL. Noninvasive localization of nuclear factor of activated T cells c1-/- mouse embryos by ultrasound biomicroscopy-Doppler allows genotype-phenotype correlation. J Am Soc Echocardiogr 2006; 18:1415-21. [PMID: 16376776 DOI: 10.1016/j.echo.2005.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Indexed: 11/28/2022]
Abstract
Ultrasound biomicroscopy (UBM)-Doppler allows study of cardiovascular physiology in the in utero mouse embryo from embryonic day (E)8.25 onward. We determined the accuracy of localization of embryos by transabdominal, noninvasive 40-MHz UBM-Doppler imaging. Nuclear factor of activated T cells c1-/- mice lack semilunar valves, exhibit outflow tract regurgitation, and die in utero. In timed pregnant mice generated from heterozygote crosses, an UBM-derived map of the in situ litter was compared with a definitive laparotomy map, and UBM-Doppler cardiac screen attempted for each embryo. All 109 living and dead (nonresorbed) E10.5 to 17.5 embryos were imaged and accurately localized. All 10 embryos with reversed diastolic aortic flow and 7 of 9 dead embryos genotyped were nuclear factor of activated T cells c1-/-. In 30 embryos followed up serially over 1 to 2 days from E12.5 to E16.5, we again achieved 100% accuracy in localizing at follow-up. Noninvasive localization and UBM-Doppler analysis of in situ mouse embryos can provide accurate genotype-phenotype correlation, along with nontraumatic serial imaging of embryos.
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Affiliation(s)
- Rui Ping Ji
- Pediatric Cardiology Program, New York University School of Medicine, New York, New York, USA
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Kulandavelu S, Qu D, Sunn N, Mu J, Rennie MY, Whiteley KJ, Walls JR, Bock NA, Sun JCH, Covelli A, Sled JG, Adamson SL. Embryonic and Neonatal Phenotyping of Genetically Engineered Mice. ILAR J 2006; 47:103-17. [PMID: 16547367 DOI: 10.1093/ilar.47.2.103] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Considerable progress has been made in adapting existing and developing new technologies to enable increasingly detailed phenotypic information to be obtained in embryonic and newborn mice. Sophisticated methods for imaging mouse embryos and newborns are available and include ultrasound and magnetic resonance imaging (MRI) for in vivo imaging, and MRI, vascular corrosion casts, micro-computed tomography, and optical projection tomography (OPT) for postmortem imaging. In addition, Doppler and M-mode ultrasound are useful noninvasive tools to monitor cardiac and vascular hemodynamics in vivo in embryos and newborns. The developmental stage of the animals being phenotyped is an important consideration when selecting the appropriate technique for anesthesia or euthanasia and for labeling animals in longitudinal studies. Study design also needs to control for possible differences between inter- and intralitter variability, and for possible long-term developmental effects caused by anesthesia and/or procedures. Noninvasive or minimally invasive intravenous or intracardiac injections or blood sampling, and arterial pressure and electrocardiography (ECG) measurements are feasible in newborns. Whereas microinjection techniques are available for embryos as young as 6.5 days of gestation, further advances are required to enable minimally invasive fluid or tissue samples, or blood pressure or ECG measurements, to be obtained from mouse embryos in utero. The growing repertoire of techniques available for phenotyping mouse embryos and newborns promises to accelerate knowledge gained from studies using genetically engineered mice to understand molecular regulation of morphogenesis and the etiology of congenital diseases.
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Shen Y, Leatherbury L, Rosenthal J, Yu Q, Pappas MA, Wessels A, Lucas J, Siegfried B, Chatterjee B, Svenson K, Lo CW. Cardiovascular phenotyping of fetal mice by noninvasive high-frequency ultrasound facilitates recovery of ENU-induced mutations causing congenital cardiac and extracardiac defects. Physiol Genomics 2006; 24:23-36. [PMID: 16174781 DOI: 10.1152/physiolgenomics.00129.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
As part of a large-scale noninvasive fetal ultrasound screen to recover ethylnitrosourea (ENU)-induced mutations causing congenital heart defects in mice, we established a high-throughput ultrasound scanning strategy for interrogating fetal mice in utero utilizing three orthogonal imaging planes defined by the fetus’ vertebral column and body axes, structures readily seen by ultrasound. This contrasts with the difficulty of acquiring clinical ultrasound imaging planes which are defined by the fetal heart. By use of the three orthogonal imaging planes for two-dimensional (2D) imaging together with color flow, spectral Doppler, and M-mode imaging, all of the major elements of the heart can be evaluated. In this manner, 10,091 ENU-mutagenized mouse fetuses were ultrasound scanned between embryonic days 12.5 and 19.5, with 324 fetuses found to die prenatally and 425 exhibiting cardiovascular defects. Further analysis by necropsy and histology showed heart defects that included conotruncal anomalies, obstructive lesions, and shunt lesions as well as other complex heart diseases. Ultrasound imaging also identified craniofacial/head defects and body wall closure defects, which necropsy revealed as encephalocele, holoprosencephaly, omphalocele, or gastroschisis. Genome scanning mapped one ENU-induced mutation associated with persistence truncus arteriosus and holoprosencephaly to mouse chromosome 2, while another mutation associated with cardiac defects and omphalocele was mapped to mouse chromosome 17. These studies show the efficacy of this novel ultrasound scanning strategy for noninvasive ultrasound phenotyping to facilitate the recovery of ENU-induced mutations causing congenital heart defects and other extracardiac anomalies.
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Affiliation(s)
- Yuan Shen
- Laboratory of Developmental Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-8019, USA
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Denvir MA, Sharif I, Anderson T, Webb DJ, Gray GA, McDicken WN. Influence of scanning frequency and ultrasonic contrast agent on reproducibility of left ventricular measurements in the mouse. J Am Soc Echocardiogr 2005; 18:155-62. [PMID: 15682053 DOI: 10.1016/j.echo.2004.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mice are now widely used as models of cardiovascular disease. Their small size and fast heart rates are technically challenging to echocardiography. This study examined the influence of different scanning frequencies and ultrasonic contrast agent (UCA) on the accuracy and reproducibility of measurements of left ventricular (LV) structure and function. METHODS Normal mouse hearts (C57BL6) were imaged at 3 different scanning frequencies before and after intravenous injection of the UCA, Optison. Coronary artery ligation mice and sham-operated controls were scanned at 10-22 MHz with and without UCA. RESULTS Scanning frequency had no significant effect on intraobserver or interobserver variation of LV measurements in normal mice under baseline conditions. Use of UCA significantly reduced estimated ejection fraction at 10-22 MHz compared with baseline (baseline 50.8 +/- 7.6% vs UCA 39.7 +/- 7.6%; P = .03) and significantly increased values for LV cavity dimensions (eg, LV area diastole 20.74 +/- 1.20 vs 23.23 +/- 0.98 mm 2 ; P = .002). UCA significantly reduced intraobserver and interobserver variation in LV ejection fraction. CONCLUSIONS Scanning frequency had no significant effect on reproducibility of LV measurements in the mouse but UCA significantly reduced interobserver variation. Use of UCA could reduce the number of mice required in any given experiment to observe a statistically significant change in LV function.
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Affiliation(s)
- Martin A Denvir
- Centre for Cardiovascular Science, Department of Medical Physics, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH14 2XU, Scotland, UK.
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16
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Yu Q, Shen Y, Chatterjee B, Siegfried BH, Leatherbury L, Rosenthal J, Lucas JF, Wessels A, Spurney CF, Wu YJ, Kirby ML, Svenson K, Lo CW. ENU induced mutations causing congenital cardiovascular anomalies. Development 2004; 131:6211-23. [PMID: 15548583 DOI: 10.1242/dev.01543] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We used non-invasive high frequency ultrasound to screen N-ethyl-N-nitrosourea mutagenized mouse fetuses for congenital cardiovascular anomalies. We ultrasound scanned 7546 mouse fetuses from 262 mutagenized families, and identified 124 families with cardiovascular defects. Represented were most of the major congenital cardiovascular anomalies seen clinically. The ENU-induced mutations in several families were mapped using polymorphic microsatellite DNA markers. One family with forelimb anomalies and ventricular septal defects, phenotypes similar to Holt-Oram syndrome, and one family with transposition of the great arteries and heart situs anomalies were mapped to different regions of mouse chromosome 4. A third mutation causing persistent truncus arteriosus and craniofacial defects, phenotypes reminiscent of DiGeorge syndrome, was mapped to mouse chromosome 2. We note that mouse chromosomes 4 and 2 do not contain Tbx5 or Tbx1, genes previously linked to Holt-Oram and DiGeorge syndromes, respectively. In two other families, the ENU-induced mutation was identified--Sema3CL605P was associated with persistent truncus arteriosus with interrupted aortic arch, and the Gja1W45X connexin43 mutation caused conotruncal malformation and coronary aneurysms. Although our screen was designed as a recessive screen, a number of the mutations showed cardiovascular phenotypes in both heterozygote and homozygote animals. These studies show the efficacy of ENU mutagenesis and high-throughput ultrasound phenotyping in recovering mutations causing a wide spectrum of congenital heart defects. These ENU-induced mutations hold promise in yielding new insights into the genetic basis for human congenital heart disease.
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Affiliation(s)
- Qing Yu
- Laboratory of Developmental Biology, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8019, USA
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Spurney CF, Leatherbury L, Lo CW. High-frequency ultrasound database profiling growth, development, and cardiovascular function in C57BL/6J mouse fetuses. J Am Soc Echocardiogr 2004; 17:893-900. [PMID: 15282495 DOI: 10.1016/j.echo.2004.04.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND High-frequency ultrasound is effective for noninvasive phenotypic analysis of cardiovascular development and function in mutagenized fetal mice. However, lacking is a normative database of echocardiographic variables for monitoring growth and cardiovascular function. METHODS C57BL/6J fetal mice were scanned in utero using an ultrasound system with a 15-MHz linear phased-array transducer. Pregnant mothers were anesthetized with 1% isoflurane mixed with 100% oxygen. Quantitative variables for monitoring fetal growth and cardiac function were obtained in several imaging planes and modalities. RESULTS Fetal growth measurements increased linearly. Inflow velocities showed significant A-wave dominance. The E wave progressively increased during development. Cardiac function was best assessed through M-mode analysis, but short-axis images were difficult to obtain. Spectral Doppler was readily obtained and the myocardial performance index was calculated. CONCLUSIONS These results provide an essential foundation for the evaluation of cardiovascular defects in mutagenized and transgenic mice.
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Affiliation(s)
- Christopher F Spurney
- Department of Cardiology, Children's National Medical Center, Washington, DC 20010, USA
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