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Peterson JC, Kelder TP, Goumans MJTH, Jongbloed MRM, DeRuiter MC. The Role of Cell Tracing and Fate Mapping Experiments in Cardiac Outflow Tract Development, New Opportunities through Emerging Technologies. J Cardiovasc Dev Dis 2021; 8:47. [PMID: 33925811 PMCID: PMC8146276 DOI: 10.3390/jcdd8050047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/18/2021] [Accepted: 04/22/2021] [Indexed: 02/07/2023] Open
Abstract
Whilst knowledge regarding the pathophysiology of congenital heart disease (CHDs) has advanced greatly in recent years, the underlying developmental processes affecting the cardiac outflow tract (OFT) such as bicuspid aortic valve, tetralogy of Fallot and transposition of the great arteries remain poorly understood. Common among CHDs affecting the OFT, is a large variation in disease phenotypes. Even though the different cell lineages contributing to OFT development have been studied for many decades, it remains challenging to relate cell lineage dynamics to the morphologic variation observed in OFT pathologies. We postulate that the variation observed in cellular contribution in these congenital heart diseases might be related to underlying cell lineage dynamics of which little is known. We believe this gap in knowledge is mainly the result of technical limitations in experimental methods used for cell lineage analysis. The aim of this review is to provide an overview of historical fate mapping and cell tracing techniques used to study OFT development and introduce emerging technologies which provide new opportunities that will aid our understanding of the cellular dynamics underlying OFT pathology.
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Affiliation(s)
- Joshua C. Peterson
- Department Anatomy & Embryology, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (J.C.P.); (T.P.K.); (M.R.M.J.)
| | - Tim P. Kelder
- Department Anatomy & Embryology, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (J.C.P.); (T.P.K.); (M.R.M.J.)
| | - Marie José T. H. Goumans
- Department Cellular and Chemical Biology, Leiden University Medical Center, 2300RC Leiden, The Netherlands;
| | - Monique R. M. Jongbloed
- Department Anatomy & Embryology, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (J.C.P.); (T.P.K.); (M.R.M.J.)
- Department of Cardiology, Leiden University Medical Center, 2300RC Leiden, The Netherlands
| | - Marco C. DeRuiter
- Department Anatomy & Embryology, Leiden University Medical Center, 2300RC Leiden, The Netherlands; (J.C.P.); (T.P.K.); (M.R.M.J.)
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2
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Abstract
Repair of arterial injury results in formation of a new structure, a neointima, that causes luminal narrowing. Smooth muscle cell (SMC) properties required for neointima formation are also found in nascent SMCs of developing blood vessels in the embryo (e.g., proliferation, extracellular matrix synthesis, cell migration). We isolated 2 distinct types of SMC from aortic media of newborn rats that were distinguished by cell shape, secretion of platelet-derived growth factor (PDGF) and insulin-like growth factor-1 (IGF-1), and expression of PDGF-B and PDGF α-receptor genes. These two SMC types did not interconvert over many cell generations in vitro. Adult rat aorta yields only one SMC type, suggesting that the “pup” SMC variant is developmentally regulated. However, SMC with the “pup” phenotype reappear in the adult artery wall during neointima formation after balloon catheter injury. These observations raise the possibility that SMC proliferation and arterial remodeling during development, repair and disease of the artery wall might depend upon a SMC subpopulation with special properties.
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Affiliation(s)
- Mark W. Majesky
- Department of Pathology, SJ-60, University of Washington, Seattle, Washington 98195
| | - Stephen M. Schwartz
- Department of Pathology, SJ-60, University of Washington, Seattle, Washington 98195
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3
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Lin CJ, Staiculescu MC, Hawes JZ, Cocciolone AJ, Hunkins BM, Roth RA, Lin CY, Mecham RP, Wagenseil JE. Heterogeneous Cellular Contributions to Elastic Laminae Formation in Arterial Wall Development. Circ Res 2019; 125:1006-1018. [PMID: 31590613 DOI: 10.1161/circresaha.119.315348] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
RATIONALE Elastin is an important ECM (extracellular matrix) protein in large and small arteries. Vascular smooth muscle cells (SMCs) produce the layered elastic laminae found in elastic arteries but synthesize little elastin in muscular arteries. However, muscular arteries have a well-defined internal elastic lamina (IEL) that separates endothelial cells (ECs) from SMCs. The extent to which ECs contribute elastin to the IEL is unknown. OBJECTIVE To use targeted elastin (Eln) deletion in mice to explore the relative contributions of SMCs and ECs to elastic laminae formation in different arteries. METHODS AND RESULTS We used SMC- and EC-specific Cre recombinase transgenes with a novel floxed Eln allele to focus gene inactivation in mice. Inactivation of Eln in SMCs using Sm22aCre resulted in depletion of elastic laminae in the arterial wall with the exception of the IEL and SMC clusters in the outer media near the adventitia. Inactivation of elastin in ECs using Tie2Cre or Cdh5Cre resulted in normal medial elastin and a typical IEL in elastic arteries. In contrast, the IEL was absent or severely disrupted in muscular arteries. Interruptions in the IEL resulted in neointimal formation in the ascending aorta but not in muscular arteries. CONCLUSIONS Combined with lineage-specific fate mapping systems, our knockout results document an unexpected heterogeneity in vascular cells that produce the elastic laminae. SMCs and ECs can independently form an IEL in most elastic arteries, whereas ECs are the major source of elastin for the IEL in muscular and resistance arteries. Neointimal formation at IEL disruptions in the ascending aorta confirms that the IEL is a critical physical barrier between SMCs and ECs in the large elastic arteries. Our studies provide new information about how SMCs and ECs contribute elastin to the arterial wall and how local elastic laminae defects may contribute to cardiovascular disease.
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Affiliation(s)
- Chien-Jung Lin
- From the Department of Cell Biology and Physiology (C.-J.L., B.M.H., R.A.R., R.P.M.).,Department of Internal Medicine, Cardiovascular Division (C.-J.L.)
| | - Marius C Staiculescu
- Department of Mechanical Engineering and Materials Science (M.C.S., J.Z.H., J.E.W.)
| | - Jie Z Hawes
- Department of Mechanical Engineering and Materials Science (M.C.S., J.Z.H., J.E.W.)
| | - Austin J Cocciolone
- Departments of Biomedical Engineering (A.J.C.), Washington University, St. Louis, MO
| | - Bridget M Hunkins
- From the Department of Cell Biology and Physiology (C.-J.L., B.M.H., R.A.R., R.P.M.)
| | - Robyn A Roth
- From the Department of Cell Biology and Physiology (C.-J.L., B.M.H., R.A.R., R.P.M.)
| | - Chieh-Yu Lin
- Pathology and Immunology (C.-Y.L.), Washington University, St. Louis, MO
| | - Robert P Mecham
- From the Department of Cell Biology and Physiology (C.-J.L., B.M.H., R.A.R., R.P.M.)
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science (M.C.S., J.Z.H., J.E.W.)
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Gabriela Espinosa M, Catalin Staiculescu M, Kim J, Marin E, Wagenseil JE. Elastic Fibers and Large Artery Mechanics in Animal Models of Development and Disease. J Biomech Eng 2019; 140:2666245. [PMID: 29222533 DOI: 10.1115/1.4038704] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Indexed: 12/21/2022]
Abstract
Development of a closed circulatory system requires that large arteries adapt to the mechanical demands of high, pulsatile pressure. Elastin and collagen uniquely address these design criteria in the low and high stress regimes, resulting in a nonlinear mechanical response. Elastin is the core component of elastic fibers, which provide the artery wall with energy storage and recoil. The integrity of the elastic fiber network is affected by component insufficiency or disorganization, leading to an array of vascular pathologies and compromised mechanical behavior. In this review, we discuss how elastic fibers are formed and how they adapt in development and disease. We discuss elastic fiber contributions to arterial mechanical behavior and remodeling. We primarily present data from mouse models with elastic fiber deficiencies, but suggest that alternate small animal models may have unique experimental advantages and the potential to provide new insights. Advanced ultrastructural and biomechanical data are constantly being used to update computational models of arterial mechanics. We discuss the progression from early phenomenological models to microstructurally motivated strain energy functions for both collagen and elastic fiber networks. Although many current models individually account for arterial adaptation, complex geometries, and fluid-solid interactions (FSIs), future models will need to include an even greater number of factors and interactions in the complex system. Among these factors, we identify the need to revisit the role of time dependence and axial growth and remodeling in large artery mechanics, especially in cardiovascular diseases that affect the mechanical integrity of the elastic fibers.
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Affiliation(s)
| | | | - Jungsil Kim
- Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130
| | - Eric Marin
- Department of Biomedical Engineering, Saint Louis University, St. Louis, MO 63103
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University, , St. Louis, MO 63130 e-mail:
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5
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Espinosa MG, Taber LA, Wagenseil JE. Reduced embryonic blood flow impacts extracellular matrix deposition in the maturing aorta. Dev Dyn 2018; 247:914-923. [PMID: 29696727 DOI: 10.1002/dvdy.24635] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/15/2018] [Accepted: 04/18/2018] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Perturbations to embryonic hemodynamics are known to adversely affect cardiovascular development. Vitelline vein ligation (VVL) is a model of reduced placental blood flow used to induce cardiac defects in early chick embryo development. The effect of these hemodynamic interventions on maturing elastic arteries is largely unknown. We hypothesize that hemodynamic changes impact maturation of the dorsal aorta (DA). RESULTS We examined the effects of VVL on hemodynamic properties well into the maturation process and the corresponding changes in aortic dimensions, wall composition, and gene expression. In chick embryos, we found that DA blood velocity was reduced immediately postsurgery at Hamburger-Hamilton (HH) stage 18 and later at HH36, but not in the interim. Throughout this period, DA diameter adapted to maintain a constant shear stress. At HH36, we found that VVL DAs showed a substantial decrease in elastin and a modest increase in collagen protein content. In VVL DAs, up-regulation of elastic fiber-related genes followed the down-regulation of flow-dependent genes. Together, these suggest the existence of a compensatory mechanism in response to shear-induced delays in maturation. CONCLUSIONS The DA's response to hemodynamic perturbations invokes coupled mechanisms for shear regulation and matrix maturation, potentially impacting the course of vascular development. Developmental Dynamics 247:914-923, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- M Gabriela Espinosa
- Department of Biomedical Engineering, Washington University, Saint Louis, Missouri
| | - Larry A Taber
- Department of Biomedical Engineering, Washington University, Saint Louis, Missouri
| | - Jessica E Wagenseil
- Department of Mechanical Engineering and Materials Science, Washington University, Saint Louis, Missouri
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6
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Lindsey SE, Menon PG, Kowalski WJ, Shekhar A, Yalcin HC, Nishimura N, Schaffer CB, Butcher JT, Pekkan K. Growth and hemodynamics after early embryonic aortic arch occlusion. Biomech Model Mechanobiol 2015; 14:735-51. [PMID: 25416845 PMCID: PMC4452432 DOI: 10.1007/s10237-014-0633-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 11/05/2014] [Indexed: 01/28/2023]
Abstract
The majority of severe clinically significant forms of congenital heart disease (CHD) are associated with great artery lesions, including hypoplastic, double, right or interrupted aortic arch morphologies. While fetal and neonatal interventions are advancing, their potential ability to restore cardiac function, optimal timing, location, and intensity required for intervention remain largely unknown. Here, we combine computational fluid dynamics (CFD) simulations with in vivo experiments to test how individual pharyngeal arch artery hemodynamics alter as a result of local interventions obstructing individual arch artery flow. Simulated isolated occlusions within each pharyngeal arch artery were created with image-derived three-dimensional (3D) reconstructions of normal chick pharyngeal arch anatomy at Hamburger-Hamilton (HH) developmental stages HH18 and HH24. Acute flow redistributions were then computed using in vivo measured subject-specific aortic sinus inflow velocity profiles. A kinematic vascular growth-rendering algorithm was then developed and implemented to test the role of changing local wall shear stress patterns in downstream 3D morphogenesis of arch arteries. CFD simulations predicted that altered pressure gradients and flow redistributions were most sensitive to occlusion of the IVth arches. To evaluate these simulations experimentally, a novel in vivo experimental model of pharyngeal arch occlusion was developed and implemented using two-photon microscopy-guided femtosecond laser-based photodisruption surgery. The right IVth arch was occluded at HH18, and resulting diameter changes were followed for up to 24 h. Pharyngeal arch diameter responses to acute hemodynamic changes were predicted qualitatively but poorly quantitatively. Chronic growth and adaptation to hemodynamic changes, however, were predicted in a subset of arches. Our findings suggest that this complex biodynamic process is governed through more complex forms of mechanobiological vascular growth rules. Other factors in addition to wall shear stress or more complex WSS rules are likely important in the long-term arterial growth and patterning. Combination in silico/experimental platforms are essential for accelerating our understanding and prediction of consequences from embryonic/fetal cardiovascular occlusions and lay the foundation for noninvasive methods to guide CHD diagnosis and fetal intervention.
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Affiliation(s)
| | - Prahlad G. Menon
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
| | - William J. Kowalski
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
| | - Akshay Shekhar
- Department of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Huseyin C. Yalcin
- Department of Mechanical Engineering, Dogus University, Istanbul, Turkey
| | - Nozomi Nishimura
- Department of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Chris B. Schaffer
- Department of Biomedical Engineering, Cornell University, Ithaca, NY
| | | | - Kerem Pekkan
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
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Pintér A, Horváth T, Tóth A, Kádár K, Kollai M. Impaired baroreflex function is related to reduced carotid artery elasticity in patients with tetralogy of Fallot. Auton Neurosci 2014; 183:94-9. [DOI: 10.1016/j.autneu.2014.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 12/02/2013] [Accepted: 02/21/2014] [Indexed: 11/30/2022]
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Dinardo CL, Venturini G, Zhou EH, Watanabe IS, Campos LCG, Dariolli R, da Motta-Leal-Filho JM, Carvalho VM, Cardozo KHM, Krieger JE, Alencar AM, Pereira AC. Variation of mechanical properties and quantitative proteomics of VSMC along the arterial tree. Am J Physiol Heart Circ Physiol 2014; 306:H505-16. [DOI: 10.1152/ajpheart.00655.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vascular smooth muscle cells (VSMCs) are thought to assume a quiescent and homogeneous mechanical behavior after arterial tree development phase. However, VSMCs are known to be molecularly heterogeneous in other aspects and their mechanics may play a role in pathological situations. Our aim was to evaluate VSMCs from different arterial beds in terms of mechanics and proteomics, as well as investigate factors that may influence this phenotype. VSMCs obtained from seven arteries were studied using optical magnetic twisting cytometry (both in static state and after stretching) and shotgun proteomics. VSMC mechanical data were correlated with anatomical parameters and ultrastructural images of their vessels of origin. Femoral, renal, abdominal aorta, carotid, mammary, and thoracic aorta exhibited descending order of stiffness (G, P < 0.001). VSMC mechanical data correlated with the vessel percentage of elastin and amount of surrounding extracellular matrix (ECM), which decreased with the distance from the heart. After 48 h of stretching simulating regional blood flow of elastic arteries, VSMCs exhibited a reduction in basal rigidity. VSMCs from the thoracic aorta expressed a significantly higher amount of proteins related to cytoskeleton structure and organization vs. VSMCs from the femoral artery. VSMCs are heterogeneous in terms of mechanical properties and expression/organization of cytoskeleton proteins along the arterial tree. The mechanical phenotype correlates with the composition of ECM and can be modulated by cyclic stretching imposed on VSMCs by blood flow circumferential stress.
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Affiliation(s)
- Carla Luana Dinardo
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Gabriela Venturini
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | - Enhua H. Zhou
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts
| | - Ii Sei Watanabe
- Institute of Biomedical Sciences, Department of Anatomy, University of São Paulo, São Paulo, Brazil
| | | | - Rafael Dariolli
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
| | | | | | | | - José Eduardo Krieger
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil
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9
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László A, Pintér A, Horváth T, Kádár K, Temesvári A, Kollai M, Studinger P. Impaired carotid artery elastic function in patients with tetralogy of Fallot. Heart Vessels 2010; 26:542-8. [PMID: 21181170 DOI: 10.1007/s00380-010-0095-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Accepted: 10/22/2010] [Indexed: 11/28/2022]
Abstract
Complex congenital heart diseases with abnormal formation of the aorticopulmonary septum are also associated with defective large artery elastogenesis. In the current study, we tested the hypothesis that carotid artery elastic function was impaired in patients with tetralogy of Fallot (ToF). The study included 45 Fallot-patients (male:female 27:18; age 21.0 ± 11.8 years) and 45 age- and gender-matched healthy control individuals. Carotid artery diameter, pulsatile distension, and intima-media thickness (IMT) were measured by echotracking device, and carotid blood pressure was determined using applanation tonometry. Carotid artery elasticity was characterized by compliance and distensibility coefficients, stiffness index β, and incremental elastic modulus. All carotid artery elastic parameters showed significant differences between groups. The compliance coefficient was 36%, and the distensibility coefficient was 33% smaller, whereas stiffness index β was 46% and incremental elastic modulus was 40% larger in Fallot-patients. Fallot-patients also had larger carotid artery IMT as compared to that of healthy individuals. Carotid artery is markedly stiffer in Fallot-patients suggesting that impaired elastogenesis is a component of the congenital abnormality. Increased large artery stiffness might contribute directly and indirectly (through impairment of baroreflex function) to the higher mortality found in ToF patients.
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Affiliation(s)
- Andrea László
- Institute of Human Physiology and Clinical Experimental Research, Faculty of Medicine, Semmelweis University, P. O. Box 448, 1446 Budapest, Hungary
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10
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Wagenseil JE, Mecham RP. Vascular extracellular matrix and arterial mechanics. Physiol Rev 2009; 89:957-89. [PMID: 19584318 DOI: 10.1152/physrev.00041.2008] [Citation(s) in RCA: 657] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
An important factor in the transition from an open to a closed circulatory system was a change in vessel wall structure and composition that enabled the large arteries to store and release energy during the cardiac cycle. The component of the arterial wall in vertebrates that accounts for these properties is the elastic fiber network organized by medial smooth muscle. Beginning with the onset of pulsatile blood flow in the developing aorta, smooth muscle cells in the vessel wall produce a complex extracellular matrix (ECM) that will ultimately define the mechanical properties that are critical for proper function of the adult vascular system. This review discusses the structural ECM proteins in the vertebrate aortic wall and will explore how the choice of ECM components has changed through evolution as the cardiovascular system became more advanced and pulse pressure increased. By correlating vessel mechanics with physiological blood pressure across animal species and in mice with altered vessel compliance, we show that cardiac and vascular development are physiologically coupled, and we provide evidence for a universal elastic modulus that controls the parameters of ECM deposition in vessel wall development. We also discuss mechanical models that can be used to design better tissue-engineered vessels and to test the efficacy of clinical treatments.
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Affiliation(s)
- Jessica E Wagenseil
- Department of Biomedical Engineering, Saint Louis University, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Hu N, Christensen DA, Agrawal AK, Beaumont C, Clark EB, Hawkins JA. Dependence of Aortic Arch Morphogenesis on Intracardiac Blood Flow in the Left Atrial Ligated Chick Embryo. Anat Rec (Hoboken) 2009; 292:652-60. [DOI: 10.1002/ar.20885] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
Population-based studies of human pregnancies show that periconceptional folate supplementation has a significant protective effect for embryos during early development, resulting in a significant reduction in developmental defects of the face, the neural tube, and the cono-truncal region of the heart. These results have been supported by experiments with animal models. An obvious quality held in common by these three anatomical regions is that the normal development of each region depends on a set of multi-potent cells that originate in the mid-dorsal region of the neural epithelium. However, the reason for the sensitive dependence of these particular cells on folic acid for normal development has not been obvious, and there is no consensus about the biological basis of the dramatic rescue with periconceptional folate supplementation. There are two principal hypotheses for the impact of folate insufficiency on development; each of these hypotheses has a micronutrient component and a genetic component. In the first hypothesis the effect of low folate is direct, limiting the availability of folic acid to cells within the embryo itself; thus compromising normal function and limiting proliferation. The second hypothetical effect is indirect: low folate disrupts methionine metabolism; homocysteine increases in the maternal serum; homocysteine induces abnormal development by inhibiting the function of N-methyl-D-aspartate (NMDA) receptors in the neural epithelium. There are three general families of genes whose level of expression may need to be considered in the context of these two related hypotheses: folate-receptor genes; genes that regulate methionine– homocysteine metabolism; NMDA-receptor genes.
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Pinter A, Laszlo A, Mersich B, Kadar K, Kollai M. Adaptation of baroreflex function to increased carotid artery stiffening in patients with transposition of great arteries. Clin Sci (Lond) 2007; 113:41-6. [PMID: 17319798 DOI: 10.1042/cs20060363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have shown previously that TGA (transposition of great arteries) is associated with increased carotid artery stiffness. It has been established that stiffening of the barosensory vessel wall results in reduced baroreceptor activation and impaired BRS (baroreflex sensitivity). In the present study we tested the hypothesis that the increased carotid artery stiffness in TGA patients was associated with reduced cardiovagal BRS. We studied 32 TGA patients aged 9–19 years, 12±3 years after surgical repair and 32 age-matched healthy control subjects. Carotid artery diastolic diameter and pulsatile distension was determined by echo wall tracking; carotid blood pressure was measured by tonometry. BRS was measured using spontaneous techniques [BRSseq and LFgain (low-frequency transfer function gain)] and by the phenylephrine method (BRSphe). Carotid artery distensibility was markedly reduced in patients as compared with controls (5.6±1.9×10−3 compared with 8.7±2.7×10−3/mmHg P<0.05, as determined using an unpaired Student's t test), but BRS was not different in patients and controls (20.3±14.7 compared with 21.7±12.7 for BRSseq; 13.1±9.2 compared with 10.6±4.5 for LFgain; and 19.1±8.6 compared with 24.8±7.2 for BRSphe respectively). Carotid artery elastic function was markedly impaired in patients with TGA, but the increased stiffness of the barosensory vessel wall was not associated with reduced BRS. It appears that attenuation of baroreceptor stimulus due to arterial stiffening may be compensated by other, possibly neural, mechanisms when it exists as a congenital abnormality.
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Affiliation(s)
- Alexandra Pinter
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary
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14
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Yamazaki Y, Sejima H, Yuguchi M, Namba Y, Isokawa K. Late Deposition of Elastin to Vertical Microfibrillar Fibers in the Presumptive Dermis of the Chick Embryonic Tarsometatarsus. Anat Rec (Hoboken) 2007; 290:1300-8. [PMID: 17724711 DOI: 10.1002/ar.20586] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Fibrillin microfibrils are integral components of elastic fibers and serve as a scaffold for elastin deposition. However, microfibrillar fibers (MFs) are not necessarily committed to develop into so-called elastic fibers. In dermis, elastin-free oxytalan MFs originating from the dermoepidermal junction are continuous to elaunin-type MFs (with a small amount of elastin) in the deeper papillary dermis, whereas the reticular dermis contains elastic fibers, or MFs embedded largely in elastin. In this study, we have investigated temporospatial patterns of elastin deposition on the MFs in tarsometatarsal presumptive dermis. While the earliest expression of elastin was demonstrated immunohistochemically as early as embryonic day 4 (ED4) in the wall of cardiac outflow and pharyngeal arch arteries, its deposition in the tarsometatarsus was first detected at ED6 in the deeper mesenchyme and at ED13 in the subectodermal mesenchyme. In the latter tissue, MFs had been organized perpendicularly to the covering ectoderm by ED4, well before an overt accumulation of collagenous matrix. Elastin deposition was observed initially in a punctate manner at ED13 and afterward became continuous along MFs. However, a characteristic spaced array of subectodermal vertical MFs was disorganized by ED17. These findings suggest that elastin deposition in the subectodermal MFs is not deployed by continuous, orderly propagation from elastic fibers in the deeper mesenchyme but occurs de novo in multiple foci along vertical MFs. Moreover, the present chronology of elastin deposition indicates that subectodermal, elastin-free MFs function as a transient, but primary fibrous structure in the presumptive dermis before the accumulation of collagenous matrix.
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Affiliation(s)
- Yosuke Yamazaki
- Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan
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15
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Mersich B, Studinger P, Lenard Z, Kadar K, Kollai M. Transposition of Great Arteries Is Associated With Increased Carotid Artery Stiffness. Hypertension 2006; 47:1197-202. [PMID: 16618837 DOI: 10.1161/01.hyp.0000218826.72592.e9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transposition of great arteries is the consequence of abnormal aorticopulmonary septation. Animal embryonic data indicate that septation and elastogenesis are related events, but human and clinical data are not available. We tested the hypothesis that large artery elastic function was impaired in patients with transposition of great arteries. We studied 34 patients aged 9 to 19 years, 12+/-3 years after atrial switch operation; 14 patients aged 7 to 9 years, 8+/-1 years after arterial switch operation; and 108 healthy control subjects matched for age. Carotid artery diastolic diameter and pulsatile distension were determined by echo wall-tracking; carotid blood pressure was measured by tonometry. Systolic pressure was higher and diastolic pressure was lower in patients than in controls. Patients with atrial and arterial switch repair were compared with their respective controls by 2-factor ANOVA. For patients with atrial switch repair versus control, stiffness index beta was 4.9+/-1.5 versus 3.1+/-1.0 (P<0.001); for patients witch arterial switch versus control, stiffness index beta was 3.8+/-1.1 versus 2.1+/-0.6 (P<0.001). Similar differences were observed for carotid compliance, distensibility, and incremental elastic modulus as well. The interaction term was not significant for any of the elastic variables, indicating that carotid stiffening was a characteristic of the condition and not the consequence of different hemodynamics. Carotid artery is markedly stiffer in patients, suggesting that impaired elastogenesis may constitute part of the congenital abnormality. Since carotid artery stiffness has been established as an independent cardiovascular risk factor, this condition may have consequences in the clinical management of these patients.
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Affiliation(s)
- Beatrix Mersich
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary
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Lucitti JL, Visconti R, Novak J, Keller BB. Increased arterial load alters aortic structural and functional properties during embryogenesis. Am J Physiol Heart Circ Physiol 2006; 291:H1919-26. [PMID: 16648183 DOI: 10.1152/ajpheart.01061.2005] [Citation(s) in RCA: 27] [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
As in the adult dorsal aorta, the embryonic dorsal aorta is an important determinant of cardiovascular function, and increased stiffness may have secondary effects on cardiac and microcirculatory development. We previously showed that acutely and chronically increased arterial load via vitelline artery ligation (VAL) increases systemic arterial stiffness. To test the hypothesis that local dorsal aortic stiffness also increases, we measured aortic pulse-wave velocity (PWV) and assessed the active and passive properties (stress and strain) of isolated aortic segments. PWV along the dorsal aorta increased acutely and chronically after VAL. Analysis of isolated aortic active properties suggests that load-exposed aortas experienced higher stress, but not strain, at similar intraluminal pressures. When smooth muscle tone was relaxed, strain decreased in VAL vessels, whereas stress became similar to control vessels. Immunohistochemical analysis revealed that although aortic smooth muscle alpha-actin content was similar between groups, more cell layers expressed smooth muscle alpha-actin, and myocyte cell shape was markedly rounder in VAL embryos. Additionally, aortic and perivascular collagen type I and III content significantly increased in load-exposed VAL vessels. Increased production of these proteins is consistent with the observed increase in aortic PWV and decreased strain in VAL passive aortic segments. Thus the embryonic dorsal aorta is sensitive to increased arterial load and adapts by altering its material properties via changes in collagen content.
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Affiliation(s)
- Jennifer L Lucitti
- Molecular Physiology and Biophysics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77071, USA.
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17
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Affiliation(s)
- Borja Fernández
- Dep. Biología Animal, Fac. Ciencias, Univ. Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain.
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18
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Visconti RP, Barth JL, Keeley FW, Little CD. Codistribution analysis of elastin and related fibrillar proteins in early vertebrate development. Matrix Biol 2003; 22:109-21. [PMID: 12782138 DOI: 10.1016/s0945-053x(03)00014-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Elastin is an extracellular matrix protein found in adult and neonatal vasculature, lung, skin and connective tissue. It is secreted as tropoelastin, a soluble protein that is cross-linked in the tissue space to form an insoluble elastin matrix. Cross-linked elastin can be found in association with several microfibril-associated proteins including fibrillin-1, fibrillin-2 and fibulin-1 suggesting that these proteins contribute to elastic fiber assembly, structure or function. To date, the earliest reported elastin expression was in the conotruncal region of the developing avian heart at 3.5 days of gestation. Here we report that elastin expression begins at significantly earlier developmental stages. Using a novel immunolabeling method, the deposition of elastin, fibrillin-1 and -2 and fibulin-1 was analyzed in avian embryos at several time points during the first 2 days of development. Elastin was found at the midline associated with axial structures such as the notochord and somites at 23 h of development. Fibrillin-1 and -2 and fibulin-1 were also expressed at the embryonic midline at this stage with fibrillin-1 and fibulin-1 showing a high degree of colocalization with elastin in fibers surrounding midline structures. The expression of these genes was confirmed by conventional immunoblotting and mRNA detection methods. Our results demonstrate that elastin polypeptide deposition occurs much earlier than was previously appreciated. Furthermore, the results suggest that elastin deposition at the early embryonic midline is accompanied by the deposition and organization of a number of extracellular matrix polypeptides. These filamentous extracellular matrix structures may act to transduce or otherwise stabilize dynamic forces generated during embryogenesis.
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Affiliation(s)
- Richard P Visconti
- Department of Cell Biology and the Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston, SC 29425, USA
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19
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Luther T, Dittert DD, Kotzsch M, Erlich J, Albrecht S, Mackman N, Müller M. Functional implications of tissue factor localization to cell-cell contacts in myocardium. J Pathol 2000; 192:121-30. [PMID: 10951409 DOI: 10.1002/1096-9896(2000)9999:9999<::aid-path667>3.0.co;2-i] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recently published studies suggest that the procoagulant receptor protein tissue factor (TF) is involved in vitro in cell adhesion and migration, via an interaction of its cytoplasmic domain with cytoskeletal proteins. Interestingly, TF is abundantly expressed in myocardium, but not in skeletal muscle. To elucidate the possible roles of TF in the myocardium, this study examined the cellular distribution of TF in relation to cytoskeletal proteins, as well as its relative amounts in different segments of premature, mature, and pathologically altered cardiac muscle. In juvenile and adult hearts, TF was predominantly detectable in the transverse part of the intercalated discs, where it co-localized with cytoskeletal proteins such as desmin and vinculin. The lowest amount of TF was observed in right atrial and the highest in left ventricular myocardium, which correlated with the number of contact sites of cardiomyocytes in these segments of the cardiac muscle. Lower levels of TF were present in structurally altered myocardium from patients with hypertension or ventricular hypertrophy. In addition, TF expression was decreased in human heart during sepsis and transiently decreased in rabbit heart in an endotoxaemia model, which indicates that a reduction in TF may contribute to cardiac failure in sepsis. The microtopography of TF at cardiomyocyte contact sites indicates that TF may play a structural role in the maintenance of cardiac muscle.
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Affiliation(s)
- T Luther
- Institute of Pathology, Technical University Dresden, Dresden, Germany.
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20
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Yoshigi M, Knott GD, Keller BB. Lumped parameter estimation for the embryonic chick vascular system: a time-domain approach using MLAB. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2000; 63:29-41. [PMID: 10927152 DOI: 10.1016/s0169-2607(00)00061-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have evaluated several lumped parameter analog models for the early chick embryonic vascular system that may be used to infer loading characteristics of the developing heart. We measured dorsal aortic pressure and flow simultaneously with a servo-null pressure system and a pulsed Doppler velocimeter. Four different analog circuit models were chosen for comparisons. We formulated the time-domain differential equations specifying the relations between pressure and flow in the models, and then estimated the lumped parameters that produced the best fit. The MLAB mathematical modeling software was used for solving differential equations, and for minimizing the difference between model-predicted values and experimental data. The traditional three-element Windkessel model with an added inductance term was most often the best-fitting model. This is compatible with the previous study using a frequency-domain approach. The procedures developed for the current study are adaptable for the study of a variety of nonlinear models, and distributed parameter models for mammalian cardiovascular development with mechanically, pharmacologically, or genetically altered conditions.
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Affiliation(s)
- M Yoshigi
- National Institutes of Health Specialized Center of Research in Pediatric Cardiovascular Diseases, Strong Children's Research Center, Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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21
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Zhou G, Price CE, Rosenquist TH, Gadson PF, Godfrey M. Partial cloning and sequencing of chick fibrillin-1 cDNA. In Vitro Cell Dev Biol Anim 2000; 36:19-25. [PMID: 10691037 DOI: 10.1290/1071-2690(2000)036<0019:pcasoc>2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The recent identification of numerous matrix genes and gene products has allowed a detailed examination of their roles in development. Two of these extracellular matrix proteins, fibrillin-1 and fibrillin-2, are components of the elastin-associated microfibrils. Given what is known about the distribution of the fibrillins in normal tissues and the abnormalities that result when mutations occur, a basic hypothesis has emerged: fibrillin-1 is primarily responsible for load bearing and providing structural integrity, whereas fibrillin-2 may be a director of elastogenesis. Nevertheless, examination of phenotypes in disorders caused by mutations in fibrillin-1 or fibrillin-2 suggests some common functions. To better understand these similar and diverse roles, it would be helpful to examine these proteins during chick development. To accomplish this goal, it is first necessary to characterize the chick homologs of the known fibrillins. In this study, the partial chick FBN1 cDNA was identified by polymerase chain reaction-aided cloning as a first step toward elucidating these goals. Sequence analysis indicated that there is striking conservation between chick and mammalian fibrillin-1 at the DNA and protein levels. Antisense and sense riboprobes were synthesized and used in in situ hybridization in stage 14 chick embryos and high levels of FBN1 transcripts were observed in the heart.
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Affiliation(s)
- G Zhou
- Munroe Center for Human Genetics, University of Nebraska Medical Center, Omaha 68198-5430, USA
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22
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Waldo KL, Lo CW, Kirby ML. Connexin 43 expression reflects neural crest patterns during cardiovascular development. Dev Biol 1999; 208:307-23. [PMID: 10191047 DOI: 10.1006/dbio.1999.9219] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used transgenic mice in which the promoter sequence for connexin 43 linked to a lacZ reporter was expressed in neural crest but not myocardial cells to document the pattern of cardiac neural crest cells in the caudal pharyngeal arches and cardiac outflow tract. Expression of lacZ was strikingly similar to that of cardiac neural crest cells in quail-chick chimeras. By using this transgenic mouse line to compare cardiac neural crest involvement in cardiac outflow septation and aortic arch artery development in mouse and chick, we were able to note differences and similarities in their cardiovascular development. Similar to neural crest cells in the chick, lacZ-positive cells formed a sheath around the persisting aortic arch arteries, comprised the aorticopulmonary septation complex, were located at the site of final fusion of the conal cushions, and populated the cardiac ganglia. In quail-chick chimeras generated for this study, neural crest cells entered the outflow tract by two pathways, submyocardially and subendocardially. In the mouse only the subendocardial population of lacZ-positive cells could be seen as the cells entered the outflow tract. In addition lacZ-positive cells completely surrounded the aortic sac prior to septation, while in the chick, neural crest cells were scattered around the aortic sac with the bulk of cells distributed in the bridging portion of the aorticopulmonary septation complex. In the chick, submyocardial populations of neural crest cells assembled on opposite sides of the aortic sac and entered the conotruncal ridges. Even though the aortic sac in the mouse was initially surrounded by lacZ-positive cells, the two outflow vessels that resulted from its septation showed differential lacZ expression. The ascending aorta was invested by lacZ-positive cells while the pulmonary trunk was devoid of lacZ staining. In the chick, both of these vessels were invested by neural crest cells, but the cells arrived secondarily by displacement from the aortic arch arteries during vessel elongation. This may indicate a difference in derivation of the pulmonary trunk in the mouse or a difference in distribution of cardiac neural crest cells. An independent mouse neural crest marker is needed to confirm whether the differences are indeed due to species differences in cardiovascular and/or neural crest development. Nevertheless, with the differences noted, we believe that this mouse model faithfully represents the location of cardiac neural crest cells. The similarities in location of lacZ-expressing cells in the mouse to that of cardiac neural crest cells in the chick suggest that this mouse is a good model for studying mammalian cardiac neural crest and that the mammalian cardiac neural crest performs functions similar to those shown for chick.
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Affiliation(s)
- K L Waldo
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia, 30912-2640, USA.
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23
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Skljarevski V, Turek M, Hakim AM. Cervical artery dissection is associated with widened aortic root diameter. Neurol Sci 1998; 25:315-9. [PMID: 9827234 DOI: 10.1017/s031716710003434x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Dissection of the internal carotid and vertebral arteries is a well recognized cause of stroke, especially in the middle-aged. The exact etiology of this condition is controversial. According to one theory there is an underlying vasculopathy originating from disturbed development of the neural crest. The neural crest gives rise to several tissues, including the tunica media of large cervical arteries and the outflow tract of the heart. We attempted to test the theory that developmental abnormality at the level of the neural crest may play a role in dissection of the large cervical arteries. METHODS We designed a retrospective case control study. By means of transthoracic echocardiography we measured the aortic root diameter in a group of patients with radiographically determined dissection of at least one large artery in the neck. The results were compared to a control group. RESULTS In comparison to age matched controls, male patients were found to have a significantly larger aortic root. Although a similar trend was apparent in females, the difference between the patient and control group of females was not statistically significant. CONCLUSIONS Patients with cervical artery dissections may have other abnormalities in other organs arising from the neural crest. A larger prospective clinical study and further research are needed to establish a firm link between dissection of the cervical arteries and abnormalities in other organs.
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Affiliation(s)
- V Skljarevski
- Division of Neurology, Ottawa Hospital-General Site, University of Ottawa, Ontario, Canada
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24
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Abstract
The initial phase of vessel formation is the establishment of nascent endothelial tubes from mesodermal precursor cells. Development of the vascular epithelium is examined using the transcription factor TAL1 as a marker of endothelial precursor cells (angioblasts), and a functional assay based on intact, whole-mounted quail embryos. Experimental studies examining the role(s) of integrins and vascular endothelial growth factor (VEGF) establish that integrin-mediated cell adhesion is necessary for normal endothelial tube formation and that stimulation of embryonic endothelial cells with exogenous VEGF results in a massive "fusion" of vessels and the obliteration of normally avascular zones. The second phase of vessel morphogenesis is assembly of the vessel wall. To understand the process by which mesenchyme gives rise to vascular smooth muscle, a novel monoclonal antibody, 1E12, that recognizes smooth muscle precursor cells was used. Additionally, development of the vessel wall was examined using the expression fo extracellular matrix proteins as markers. Comparison of labeling patterns of 1E12 and the extracellular matrix molecules fibulin-1 and fibrillin-2 indicate vessel wall heterogeneity at the earliest stages of development; thus smooth muscle cell diversity is manifested during the differentiation and assembly of the vessel wall. From these studies it is postulated that the extracellular matrix composition of the vessel wall may prove to be the best marker of smooth muscle diversity. The data are discussed in the context of recent work by others, especially provocative new studies suggesting an endothelial origin for vascular smooth muscle cells. Also discussed is recent work that provides clues to the mechanism of vascular smooth muscle induction and recruitment. Based on these findings, vascular smooth muscle cells can be thought of as existing along a continuum of phenotypes. This spectrum varies from mainly matrix-producing cells to primarily contractile cells; thus no one cell type typifies vascular smooth muscle. This view of the smooth muscle cell is considered in terms of a contrasting opinion that views smooth muscle cell as existing in either a synthetic or proliferative state.
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Affiliation(s)
- C J Drake
- Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston 29425-2204, USA
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25
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Rongish BJ, Drake CJ, Argraves WS, Little CD. Identification of the developmental marker, JB3-antigen, as fibrillin-2 and its de novo organization into embryonic microfibrous arrays. Dev Dyn 1998; 212:461-71. [PMID: 9671949 DOI: 10.1002/(sici)1097-0177(199807)212:3<461::aid-aja13>3.0.co;2-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The monoclonal antibody JB3 was previously shown to react with a protein antigen present in the bilateral primitive heart-forming regions and septation-stage embryonic hearts; in addition, primary axial structures at primitive streak stages are JB3-immunopositive (Wunsch et al. [1994] Dev. Biol. 165:585-601). The JB3 antigen has an overlapping distribution pattern with fibrillin-1, and a similar molecular mass (Gallagher et al. [1993] Dev. Dyn. 196:70-78; Wunsch et al. [1994] Dev. Biol. 165:585-601). Here we present immunoblot and immunoprecipitation data showing that the JB3 antigen is secreted into tissue culture medium by day 10 chicken embryonic fibroblasts, from which it can be harvested using JB3-immunoaffinity chromatography. A single polypeptide (Mr = 350,000), which was not immunoreactive with an antibody to fibrillin-1, eluted from the affinity column. Mass spectroscopy peptide microsequencing determined the identity of the JB3 antigen to be an avian homologue of fibrillin-2. Live, whole-mounted, quail embryos were immunolabeled using a novel microinjection approach, and subsequently fixed. Laser scanning confocal microscopy indicated an elaborate scaffold of fibrillin-2 filaments encasing formed somites. At more caudal axial positions, discrete, punctate foci of immunofluorescent fibrillin-2 were observed; this pattern corresponded to the position of segmental plate mesoderm. Between segmental plate mesoderm and fully-formed somites, progressively longer filamentous assemblies of fibrillin-2 were observed, suggesting a developmental progression of fibrillin-2 fibril assembly across the somite-forming region of avian embryos. Extensive filaments of fibrillin-2 connect somites to the notochord. Similarly, fibrillin-2 connects the mesoderm associated with the anterior intestinal portal to the midline. Thus, fibrillin-2 fibrils are organized by a diverse group of cells of mesodermal or mesodermally derived mesenchymal origin. Fibrillin-2 microfilaments are assembled in a temporal and spatial pattern that is coincident with cranial-to-caudal segmentation, and regression of the anterior intestinal portal. Fibrillin-2 may function to impart physical stability to embryonic tissues during morphogenesis of the basic vertebrate body plan.
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Affiliation(s)
- B J Rongish
- Department of Cell Biology and Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston 29425, USA
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26
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Ya J, van den Hoff MJ, de Boer PA, Tesink-Taekema S, Franco D, Moorman AF, Lamers WH. Normal development of the outflow tract in the rat. Circ Res 1998; 82:464-72. [PMID: 9506707 DOI: 10.1161/01.res.82.4.464] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The outflow tract (OFT) provides the structural components forming the ventriculoarterial connection. The prevailing concept that this junction "rotates" to acquire its definitive topography also requires a concept of "counterrotation" and is difficult to reconcile with cell-marking studies. Rats between 10 embryonic days (EDs) and 2 postnatal days were stained immunohistochemically and by in situ hybridization. DNA replication was determined by incorporation of bromodeoxyuridine and apoptosis by the annexin V binding and terminal deoxynucleotidyl transferase-mediated dUTP-X nick end labeling (TUNEL) assays. Starting at ED12, cardiomyocytes in the distal (truncal) part of the OFT begin to shed their myocardial phenotype without proceeding into apoptosis, suggesting transdifferentiation. Myocardial regression is most pronounced on the dextroposterior side and continues until after birth, as revealed by the disappearance of the myocardial cuff surrounding the coronary roots and semilunar sinuses and by the establishment of fibrous continuity between mitral and aortic semilunar valves. Fusion of the endocardial ridges of the truncus on late ED13 is accompanied by the organization of alpha-smooth muscle actin-and nonmuscle myosin heavy chain-positive myofibroblasts into a central whorl and the appearance of the semilunar valve anlagen at their definitive topographical position within the proximal portion of the truncus. After fusion of the proximal (conal) portion of the endocardial ridges, many of the resident myofibroblasts undergo apoptosis and are replaced by cardiomyocytes. The distal myocardial boundary of the OFT is not a stable landmark but moves proximally over the spiraling course of the aortic and pulmonary routes, so that the semilunar valves develop at their definitive topographic position. After septation, the distal boundary of the OFT continues to regress, particularly in its subaortic portion. The myocardializing conus septum, on the other hand, becomes largely incorporated into the right ventricle. These opposite developments account for the pronounced asymmetry of the subaortic and subpulmonary outlets in the formed heart.
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Affiliation(s)
- J Ya
- Department of Anatomy and Embryology, Academic Medical Center, University of Amsterdam, The Netherlands
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27
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Rosenquist TH, Ratashak SA, Selhub J. Homocysteine induces congenital defects of the heart and neural tube: effect of folic acid. Proc Natl Acad Sci U S A 1996; 93:15227-32. [PMID: 8986792 PMCID: PMC26385 DOI: 10.1073/pnas.93.26.15227] [Citation(s) in RCA: 279] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The biological basis or mechanism whereby folate supplementation protects against heart and neural tube defect is unknown. It has been hypothesized that the amino acid homocysteine may be the teratogenic agent, since serum homocysteine increases in folate depletion; however, this hypothesis has not been tested. In this study, avian embryos were treated directly with D,L-homocysteine or with L-homocysteine thiolactone, and a dose response was established. Of embryos treated with 50 microliters of the teratogenic dose (200 mM D,L-homocysteine or 100 mM L-homocysteine thiolactone) on incubation days 0, 1, and 2 and harvested at 53 h (stage 14), 27% showed neural tube defects. To determine the effect of the teratogenic dose on the process of heart septation, embryos were treated during incubation days 2, 3, and 4; then they were harvested at day 9 following the completion of septation. Of surviving embryos, 23% showed ventricular septal defects, and 11% showed neural tube defects. A high percentage of the day 9 embryos also showed a ventral closure defect. The teratogenic dose was shown to raise serum homocysteine to over 150 nmol/ml, compared with a normal level of about 10 nmol/ml. Folate supplementation kept the rise in serum homocysteine to approximately 45 nmol/ml, and prevented the teratogenic effect. These results support the hypothesis that homocysteine per se causes dysmorphogenesis of the heart and neural tube, as well as of the ventral wall.
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Affiliation(s)
- T H Rosenquist
- Department of Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha 68198-6395, USA
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28
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Bergwerff M, DeRuiter MC, Poelmann RE, Gittenberger-de Groot AC. Onset of elastogenesis and downregulation of smooth muscle actin as distinguishing phenomena in artery differentiation in the chick embryo. ANATOMY AND EMBRYOLOGY 1996; 194:545-57. [PMID: 8957531 DOI: 10.1007/bf00187468] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
During development, the arterial system is grossly divided into elastic and muscular vessel types. Apart from local environmental factors, it has been suggested that vascular smooth muscle cell origin (mesoderm or neural crest) is involved in this, as yet poorly understood, arterial differentiation. We describe differentiation of the thoracic arterial system in the chick embryo, using immunohistochemical techniques staining for muscle-specific actin, vinculin and desmin and histological staining to visualise elastin. The initial developmental stages of the vessel wall in all arteries appeared to be highly similar, with all arteries showing peri-endothelial actin and vinculin staining. Major alterations did not occur until the start of elastogenesis, which coincided with complete loss of actin staining from the proximal part of the great arteries. Later in development, however, actin was re-expressed in a subpopulation of medial cells, which also expressed vinculin and desmin. Concomitantly another, nonmuscular, cell type became evident in the great arteries. Transient loss of actin expression and segregation of very distinct cell populations occurred only in vessels prone to elastic development and known to receive a neural crest contribution. In contrast, arteries that developed a muscular phenotype never lost the initially acquired peri-endothelial actin expression. We also show a significant difference in the organisation of elastic fibres between elastic vessels that contain neural crest derivatives and those that do not. The ductus arteriosus still presents as an enigma in the sense that it is the only part of the pharyngeal arch complex that develops a muscular phenotype.
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Affiliation(s)
- M Bergwerff
- Department of Anatomy and Embryology, Leiden University, The Netherlands
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29
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Abstract
The calculation and modeling of vascular input impedance are based on the assumption that pressure and flow are linearly related in the frequency domain. However, this assumption has not been proven for the embryonic circulation. Therefore, we investigated the linearity of pulsatile pressure flow relations in vivo with acute alterations in cycle length. We simultaneously measured dorsal aortic pressure with a servonull system and flow velocity with a 20-MHz pulsed-Doppler system in stage 24 chick embryos (n = 38). Cycle length was acutely altered using thermal probe(s) applied to the sinus venosus. We determined the impedance spectra at several cycle lengths for each embryo and a reference curve from a three-element Windkessel model with the use of nonlinear curve fitting. We then assessed the scatter of experimental impedance along the reference curve as a measure of linearity in the frequency domain. We found that mean vascular resistance did not change after thermal probe applications (P > .20 for each), indicating that acute alterations in cycle length did not alter peripheral vascular properties. Superpositioned impedance spectra showed minimal scatter along the model impedance from 0 to 6 Hz. Goodness of fit values (R2) were near unity (.94 to .97) and were similar for all interventions (P > .07 for Fisher's z, by F test). Above 6 Hz, both modulus and phase spectra exhibited significant scatter (P < .05, by F test). Experimental impedance spectra tended to have a fluctuation and a phase-zero crossover, indicating significant wave reflection in the embryonic circulation. Thus, the embryonic vascular system can be approximated as a linear system from 0 to 6 Hz, the range in which the majority (96.0 +/- 0.18%) of hydraulic energy is dissipated.
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Affiliation(s)
- M Yoshigi
- Strong Children's Research Center, Department of Pediatrics, University of Rochester, School of Medicine and Dentistry, NY, USA.
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30
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Abstract
BACKGROUND The interaction of cells and extracellular matrix (ECM) components is important in the morphogenesis of the developing heart and is thought be mediated in part by adhesion plaques associated with vinculin, paxillin, talin, integrin, and other proteins. We investigated the patterns of expression of vinculin in the early embryonic rat heart to evaluate the role of vinculin in cardiac morphogenesis. METHODS Vinculin expression was studied immunohistochemically in developing Sprague-Dawley embryonic rat hearts between days 11.5 and 15.5. RESULTS Vinculin expression was transient and specific in the aorticopulmonary septum on day 13.5 and in the conal septum on day 14.5, when the respective septations were complete. Less vinculin immunoreactivity was detected in the atrioventricular cushion or ventricular septum, where obvious morphological alteration takes place. CONCLUSIONS Sites that were immunoreactive for vinculin in the present study are reportedly associated with the distribution of neural cell adhesion molecules (N-CAM) or of soluble tropoelastin. Thus vinculin appears to play a key role in aorticopulmonary septation, where neural crest cells are transformed into ectomesenchyme. Vinculin appears to be involved in elastogenesis and is contributed by ectomesenchyme derived from the neural crest cells.
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Affiliation(s)
- H Okagawa
- Department of Pediatrics, Shiga University of Medical Science, Japan
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31
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32
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Abstract
The embryonic extracellular matrix, which is comprised of glycosaminoglycans, glycoproteins, collagens, and proteoglycans, is believed to play multiple roles during heart morphogenesis. Some of these ECM components appear throughout development, however, certain molecules exhibit an interesting transient spatial and temporal distribution. Due to significant new data that have been gathered predominantly in the past 10 years, a comprehensive review of the literature is needed. The intent of this review is to highlight work that addresses mechanisms by which extracellular matrix influences vertebrate heart development.
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Affiliation(s)
- C D Little
- Department of Cell Biology, Medical University of South Carolina, Charleston 29425-2204, USA
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33
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Thieszen SL, Rosenquist TH. Expression of collagens and decorin during aortic arch artery development: implications for matrix pattern formation. Matrix Biol 1995; 14:573-82. [PMID: 8535607 DOI: 10.1016/s0945-053x(05)80006-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The elastic matrix of the large arteries shows a high level of spatial order. However, the mechanisms by which such order is established and maintained are largely unknown. The embryonic development of the avian heart and great vessels provides an appropriate model to investigate these mechanisms. In control embryos, an elastic matrix with a high level of spatial order develops in the nascent great vessels. But after the normal vascular smooth muscle (VSM) progenitor cells in the great vessels are experimentally replaced by other VSM progenitor cells, the elastic extracellular matrix is congenitally disordered. The present study used this model to test the hypothesis that the proteoglycan decorin was involved in the establishment and maintenance of the normal three-dimensional spatial order of the vascular elastic matrix. The temporospatial expression of decorin was analysed during development of normal vessels and in experimental vessels with surrogate VSM. The results showed the following: (1) the expression of decorin was related in time and space to the establishment of large helical collagen type III fibers that are characteristic of the normal elastic extracellular matrix; (2) in the experimental extracellular matrix there were few helical fibers of collagen type III, but those that were present remained positive for decorin; and (3) in both control and experimental vessels, decorin associated with neither fibers of collagen type I nor fibers of collagen type III in any conformation other than the large helical fibers. These data indicate a previously unrecognized relationship between decorin and the spatial order of the physiologically significant helical fibers of collagen type III.
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Affiliation(s)
- S L Thieszen
- Department of Pathology and Microbiology, University of Nebraska Omaha, USA
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Hurle JM, Corson G, Daniels K, Reiter RS, Sakai LY, Solursh M. Elastin exhibits a distinctive temporal and spatial pattern of distribution in the developing chick limb in association with the establishment of the cartilaginous skeleton. J Cell Sci 1994; 107 ( Pt 9):2623-34. [PMID: 7844176 DOI: 10.1242/jcs.107.9.2623] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this work we have analyzed the presence of elastic components in the extracellular matrices of the developing chick leg bud. The distributions of elastin and fibrillin were studied immunohistochemically in whole-mount preparations using confocal laser microscopy. The association of these constituents of the elastic matrix with other components of the extracellular matrix was also studied, using several additional antibodies. Our results reveal the transient presence of an elastin-rich scaffold of extracellular matrix fibrillar material in association with the establishment of the cartilaginous skeleton of the leg bud. The scaffold consisted of elastin-positive fibers extending from the ectodermal surface of the limb to the central cartilage-forming regions and between adjacent cartilages. Fibrillin immunolabeling was negative in this fibrillar scaffold while other components of the extracellular matrix including: tenascin, laminin and collagens type I, type III and type VI; appeared codistributed with elastin in some regions of the scaffold. Progressive changes in the spatial pattern of distribution of the elastin-positive scaffold were detected in explant cultures in which one expects a modification in the mechanical stresses of the tissues related to growth. A scaffold of elastin comparable to that found in vivo was also observed in high-density micromass cultures of isolated limb mesodermal cells. In this case the elastic fibers are observed filling the spaces located between the cartilaginous nodules. The fibers become reoriented and attach to the ectodermal basal surface when an ectodermal fragment is located at the top of the growing micromass. Our results suggest that the formation of the cartilaginous skeleton of the limb involves the segregation of the undifferentiated limb mesenchyme into chondrogenic and elastogenic cell lineages. Further, a role for the elastic fiber scaffold in coordinating the size and the spatial location of the cartilaginous skeletal elements within the limb bud is also suggested from our observations.
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Affiliation(s)
- J M Hurle
- Department of Biological Sciences, University of Iowa, Iowa City 52242
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Hurle JM, Kitten GT, Sakai LY, Volpin D, Solursh M. Elastic extracellular matrix of the embryonic chick heart: an immunohistological study using laser confocal microscopy. Dev Dyn 1994; 200:321-32. [PMID: 7994079 DOI: 10.1002/aja.1002000407] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The "elastic matrix" constitutes a specialized component of the extracellular matrix which confers resiliency to tissues and organs subjected to repeated deformations. The role of the elastic matrix in living organisms appears to be of key importance since diseases characterized by expression of defective inherited genes which encode components of the elastic matrix lead to premature death. While the elastic matrix of adult organs has received a great deal of attention, little is known about when it first appears in embryonic tissues or its possible role in developing organs. In the present study we have performed an immunohistochemical study of the distribution of elastin and three additional components often associated with elastic matrices in adult tissues (i.e., fibrillin, emilin, and type VI collagen) during the development of the chicken embryonic heart. The three-dimensional arrangement of these components was established through the observation of whole-amount specimens with scanning laser confocal microscopy. Our results revealed three different periods of heart development regarding the composition of the elastic matrix. Prior to stage 21 the embryonic heart lacks elastin but exhibits a matrix scaffold of fibrillin and emilin associated with the endocardium and the developing cardiac jelly. Between stages 22 and 29 the heart shows a transient elastic scaffold in the outflow tract which contains elastin, fibrillin, and emilin. Elastin-positive fibrillar material is also observed during these stages in the base of the atrioventricular cushion adjacent to the myocardial wall. In addition, emilin-positive material appears to be associated with the zones of formation of ventricular trabeculae. Collagen type VI was not detected during these early stages. From stage 30 to stage 40 a progressive modification of the pattern of distribution of elastin, fibrillin, emilin, and collagen type VI is observed in association with the formation of the definitive four-chambered heart. The distribution of the elastic scaffold in the outflow tract appears to be rearranged and becomes restricted to the roots of the main arteries. Each of the components studied here is also deposited at increasing levels in the developing valvular apparatus including the valve leaflets and the chordae tendinea. The components are also present in the subendocardial space where they form aligned fibrillar tracts, an arrangement suggestive of a role in ventricular contractile function. The epicardium constitutes an additional region of elastic matrix deposition during these later stages and contains elastic, fibrillin, and collagen type VI.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J M Hurle
- Department of Biological Sciences, University of Iowa, Iowa City 52242
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36
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Cook CL, Weiser MC, Schwartz PE, Jones CL, Majack RA. Developmentally timed expression of an embryonic growth phenotype in vascular smooth muscle cells. Circ Res 1994; 74:189-96. [PMID: 8293558 DOI: 10.1161/01.res.74.2.189] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Little is known about the phenotypic changes that occur in vascular smooth muscle cells (SMCs) as the developing aorta undergoes the transition from a loosely organized, highly replicative tissue to a morphologically mature, quiescent tissue. In the present study, we have characterized the in vivo pattern of SMC replication during intrauterine and neonatal aortic development in the rat and have cultured and assessed the in vitro growth properties of embryonic, fetal, and neonatal vascular SMCs. Embryonic SMCs, which exhibited a very high in vivo replication rate (75% to 80% per day), demonstrated a significant potential for self-driven replication, as assessed by the ability to proliferate under serum-deprived conditions. Several lines of evidence suggest that the autonomous growth of SMCs in the "embryonic growth phenotype" may be driven by a unique mechanism independent of known adult SMC mitogens: embryonic SMC replication was not associated with the detectable secretion of mitogenic activity capable of stimulating adult SMCs, and embryonic SMCs were mitogenically unresponsive to a variety of known adult SMC growth factors. The capacity for self-driven growth was lost by embryonic day 20, suggesting that important changes in gene expression and phenotype occur in developing SMCs between embryonic days 18 and 20. Taken together, the data describe a unique embryonic growth phenotype of vascular SMCs and suggest that the replication of aortic SMCs during intrauterine development is self driven, self regulated, and controlled by a developmental timing mechanism. The conversion of SMCs from the embryonic to the late fetal/adult growth phenotype will likely be found to be an important component of a developmental system controlling vascular morphogenesis.
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Affiliation(s)
- C L Cook
- Department of Pediatrics, University of Colorado Health Sciences Center, Denver 80262
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37
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Holzenberger M, Lièvre CA, Robert L. Tropoelastin gene expression in the developing vascular system of the chicken: an in situ hybridization study. ANATOMY AND EMBRYOLOGY 1993; 188:481-92. [PMID: 8311254 DOI: 10.1007/bf00190142] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Temporal and spatial patterns in the accumulation of Tropoelastin (TE) mRNA during development of the chick embryo were established by in situ hybridization. Radiolabeled oligonucleotide probes of high specific activity were hybridized to serial sections of the cardiovascular system from embryonic day 3.5 (ED 3.5) to ED 19. Tropoelastin mRNA was observed as early as ED 3.5 in the dorsal part of the arterial trunk. During septation varying levels of TE mRNA were seen in the pulmonary trunk, the aorta and the aorticopulmonary septum. Thereafter TE mRNA levels increased up to ED 12, and the appearance of message was distributed distally in the walls of developing arteries. From ED 4.5 on, we found a decreasing proximo-distal gradient of the hybridization signal along the trunks and later along the main arteries (longitudinal gradient), and a radial gradient through the arterial vessel wall with the highest levels of TE mRNA in the outer layers of the media. Both gradients persisted in all major arterial vessels except in the proximal systemic and pulmonary trunks, where the original radial gradient was inverted or locally bimodal during the second half of development. The valvular region of aortic and pulmonary trunks showed particularly striking patterns of TE mRNA distribution, notably a prominent label on the endothelial cell layer on aortic and pulmonary valves. Outside the cardiovascular system, TE mRNA was mainly present in prochondral or perichondral cells in trachea and growing skeleton, and in the gap of growing joints. In kidney or nephric primordia, TE mRNA was only detectable in the wall of renal arteries. A hybridization signal was observed on mesenchyme of pulmonary septae at ED 16. Our results suggest a complex regulation of elastin gene expression during development, particularly within the proximal regions of the large arterial vessels.
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Affiliation(s)
- M Holzenberger
- Laboratoire de Biologie du Tissu Conjonctif, CNRS URA 1460, Faculté de Médecine, Université de Paris XII, Créteil, France
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Gadson PF, Rossignol C, McCoy J, Rosenquist TH. Expression of elastin, smooth muscle alpha-actin, and c-jun as a function of the embryonic lineage of vascular smooth muscle cells. In Vitro Cell Dev Biol Anim 1993; 29A:773-81. [PMID: 8118612 DOI: 10.1007/bf02634344] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the avian embryo, vascular smooth muscle cells (VSMC) in the aortic arch (elastic) arteries originate in the neural crest, whereas other VSMC develop from local mesoderm. These two lineages have been shown previously to be significantly different in the timing and expression of the smooth muscle phenotype and in their respective abilities to produce an orderly elastic matrix. Two differing kinds of VSMC also have been shown in mammals. In the experimental absence of neural crest (NC) in the avian embryo, the matrix is spatially disordered. The molecular basis of the difference between the normal NC-VSMC and the surrogate mesodermal (MDM)-VSMC has not previously been investigated. In this study the expression of vascular smooth muscle alpha-actin, tropoelastin, c-fos and c-jun were examined via immunoblotting, immunohistochemistry, Northern blot, and/or transcription run-on assays. Control avian VSMC of NC origin were compared with experimental MDM-derived VSMC that populate the cardiac outflow after surgical ablation of the NC. The results show that, when they are grown under identical conditions in vitro or freshly removed from an embryonic vessel, surrogate MDM-VSMC express about 10 times more alpha-actin and tropoelastin than the normal NC-VSMC; and MDM-VSMC express up to 15 times more c-jun, whereas c-fos was not different. These results show profound heterogeneity in the regulation of VSMC-specific genes that is based in the embryonic lineage of the cells.
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Affiliation(s)
- P F Gadson
- Department of Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha 68198
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Thurkow EW, Wenink AC. Development of the ventriculoarterial segment of the human embryonic heart: a morphometrics study. Anat Rec (Hoboken) 1993; 236:664-70. [PMID: 8379590 DOI: 10.1002/ar.1092360410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In the literature, discussions continue on the question whether the distal portion of the cardiac outlet segment (ventriculoarterial portion, outflow tract of the embryonic heart) is subject to a shortening (absorption, retraction) during development. In 28 human embryos ranging from 4-42 mm crown-rump length, stereological estimates of volume fractions and surface densities were used to calculate the diameter and the length of the distal outlet segment and their changes during development. A significant increase was found in the wall thickness of this segment, whereas its length remained about the same. An actual shortening was not found. It is concluded that the relative change in proportions is the cause of the disagreements. It is further concluded that there is still a mechanical role for the aorticopulmonary septum in maintaining the length of the outlet segment during growth of this region.
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Affiliation(s)
- E W Thurkow
- Department of Anatomy and Embryology, University of Leiden, The Netherlands
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40
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Topouzis S, Catravas JD, Ryan JW, Rosenquist TH. Influence of vascular smooth muscle heterogeneity on angiotensin converting enzyme activity in chicken embryonic aorta and in endothelial cells in culture. Circ Res 1992; 71:923-31. [PMID: 1325298 DOI: 10.1161/01.res.71.4.923] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The smooth muscle of the abdominal region of the chicken aorta derives from locally recruited mesenchyme (mesenchymal smooth muscle), whereas that of the thoracic region derives from the neural crest (ectomesenchymal smooth muscle). We hypothesized that this smooth muscle heterogeneity might affect important enzymatic functions of the vessel wall. Therefore, we measured angiotensin converting enzyme (ACE) activity in homogenates of chicken thoracic and abdominal aorta at different embryonic stages (days 10, 14, and 18 of gestation). ACE activity increased in both regions over the time of gestation (p less than 0.001 in both cases); the increase was steeper and ACE activity was higher in thoracic than in abdominal segments (p less than 0.001). Km values were similar (approximately 7 microM) at all times and between the two segments, whereas changes in Vmax values closely paralleled those in enzyme activity, indicating gestation-dependent increases in the amount of enzyme. Neural crest ablation at an early developmental stage resulted in an increase of ACE activity in thoracic homogenates (p less than 0.001), predictably leaving that in abdominal homogenates unaffected. Bovine pulmonary artery endothelial cell monolayers exposed to media conditioned with cultured mesenchymal or ectomesenchymal smooth muscle cells exhibited elevated ACE activity (46% and 83%, respectively, relative to control medium, with p less than 0.01 in both cases; p less than 0.05 between the two media). Increases in endothelial cell ACE activity corresponded to proportional increases in ACE protein determined by enzyme-linked immunosorbent assay (r = 0.99) and were interpreted as indicative of enhanced enzyme synthesis subsequent to exposure of endothelial cells to smooth muscle-conditioned media.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Topouzis
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta 30912-2300
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41
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Majesky MW, Giachelli CM, Reidy MA, Schwartz SM. Rat carotid neointimal smooth muscle cells reexpress a developmentally regulated mRNA phenotype during repair of arterial injury. Circ Res 1992; 71:759-68. [PMID: 1516153 DOI: 10.1161/01.res.71.4.759] [Citation(s) in RCA: 161] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Smooth muscle cells (SMCs) cultured from the neointima of injured rat carotid arteries have a different shape and organization in vitro than SMCs from the uninjured media. The morphology of neointimal SMCs from adult rats strongly resembles that of a subset of medial SMCs from 12-day-old rat pups. In the present study, we show that adult carotid neointimal SMCs in vitro express the platelet-derived growth factor (PDGF)-B gene but have little or no PDGF alpha-receptor mRNA. In contrast, medial SMCs from contralateral uninjured carotids, grown and passaged under identical conditions, contain abundant PDGF alpha-receptor mRNA but little or no PDGF-B mRNA. Transcript levels for PDGF-A or PDGF beta-receptor were not different in neointimal versus medial SMC cultures. The PDGF mRNA phenotype of adult neointimal SMCs strongly resembles that of an aortic medial SMC subset from newborn rat pups. Although intriguing, the differences in SMC phenotypes we observed in cell culture may depend on unique conditions in vitro and do not necessarily mean that analogous SMC diversity also exists in vivo. To address this question, we constructed and screened a SMC cDNA library for additional molecular markers of the common "pup-intimal" SMC phenotype. Two cDNA clones were identified whose cognate mRNA levels were developmentally regulated in rat aorta in vivo and were present at high levels in the adult carotid neointima formed 2 weeks after balloon catheter injury. Importantly, elevated levels of these two cognate mRNAs in carotid neointima compared with underlying media were maintained in cultures of neointimal versus medial SMCs in vitro. DNA sequence analysis indicated that the cDNA clones encoded rat tropoelastin and alpha 1 procollagen (type I). These results provide further evidence that neointima formation in the adult rat carotid artery depends on reexpression of an SMC phenotype or subpopulation with special properties characteristic of earlier stages of artery wall development. Our studies to date indicate that two of these special properties are paracrine growth factor production and extracellular matrix synthesis.
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Affiliation(s)
- M W Majesky
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030
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42
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Selmin O, Volpin D, Bressan GM. Changes of cellular expression of mRNA for tropoelastin in the intraembryonic arterial vessels of developing chick revealed by in situ hybridization. MATRIX (STUTTGART, GERMANY) 1991; 11:347-58. [PMID: 1811165 DOI: 10.1016/s0934-8832(11)80206-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The pattern of expression of tropoelastin mRNA in the arterial tree of developing chick has been studied by in situ hybridization. Significant hybridization was noted in 5.5-day embryos in the region of the truncus arteriosus where aorta and pulmonary artery had newly separated. The activation of expression then propagated centrifugally and longitudinal gradients of mRNA decreasing from the heart to the periphery were established. For almost two-thirds of the embryonic period, the hybridization signal was rather uniform over the entire wall of the arterial vessels. Later, however, its distribution varied depending on the type of artery (elastic or muscular) and on the developmental stage. A radial gradient of tropoelastin mRNA expression decreasing in the in-out direction was formed in elastic arteries. This was first seen in the pulmonary artery (15-day chick embryos) and became detectable in the vessels of the general circulation only much later (2 weeks after hatching). The appearance of the radial gradient was followed by a general reduction of mRNA synthesis. In muscular arteries radial gradients were also established, but had, however, an opposite polarity; in small arteries a ring of hybridization was evident at the media-adventitia border. The results indicate that the expression of the tropoelastin gene in cells of the arterial wall is finely regulated, depending on the coordinates in the arterial tree, the type of artery and the organ supplied.
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Affiliation(s)
- O Selmin
- Institute of Histology and Embryology, University of Padova, Italy
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43
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Rosenquist TH, Módis L. Spatial disorder of collagens in the great vessels, associated with congenital heart defects. Anat Rec (Hoboken) 1991; 229:116-24. [PMID: 1996777 DOI: 10.1002/ar.1092290113] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Surgical ablation of the cardiac neural crest from the chicken embryo results in persistent truncus arteriosus (PTA) and a change in the elastic laminae of the great vessels, wherein elastin and the elastin microfibril show significant spatial disorder. The purpose of this study was to test the hypothesis that the interstitial collagens would also be disordered in the elastic laminae of chicken embryos with PTA. The birefringence characteristics of interstitial collagen were examined to evaluate spatial ordering. The results showed that collagen in the elastic laminae assumed an orderly configuration of well-defined fiber bundles in the great vessel walls of control embryos, whereas vessels from embryos with PTA lacked any distinct spatial order. Collagens type I and III were localized in the vessel walls. Type III collagen was the principal collagen of the elastic laminae, but was absent from the intima of all vessels. In the elastic laminae of vessels from control embryos, collagen type III showed well-defined fiber bundles whereas embryos with PTA had diffuse collagen type III in poorly defined laminae that were not separated by discrete layers of smooth muscle cells. Collagen type I was a minor component of the elastic laminae but formed robust pericellular fiber bundles throughout the media and intima. Collagen type I fibers appeared to be coarsened and less uniform in the vessels from embryos with PTA.
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Affiliation(s)
- T H Rosenquist
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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Rosenquist TH, Fray-Gavalas C, Waldo K, Beall AC. Development of the musculoelastic septation complex in the avian truncus arteriosus. THE AMERICAN JOURNAL OF ANATOMY 1990; 189:339-56. [PMID: 2285042 DOI: 10.1002/aja.1001890406] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is now well established that cells from the cardiac neural crest (CNC) are essential for normal conotruncal septation. The truncal septation complex consists of the aorticopulmonary (AP) septum and the myocardial sheath of the truncus. The principal role of the CNC cells during septation appears to be their differentiation into the elastogenic smooth muscle that forms the AP septum proper. The objective of this study was to integrate serial reconstruction and specific histochemical markers in order to provide a unified analysis of the relationships between the CNC and the other components of the truncal septation complex. The development of the septation complex was compared normal embryos vs. embryos from which the CNC had been surgically ablated. Embryos from each group were harvested after incubation periods of 4-8 days (Hamburger-Hamilton stages 23-34). Histochemical procedures were performed for positive identification of the elastic matrix and smooth muscle alpha-actin; the presence of these proteins was used as the criterion for "septal cells" and to define the boundaries of the septum. The results indicate that the shape, components, boundaries, and degree of organization of the septation complex may be different from previous descriptions. Furthermore, all of the components of the truncal septation complex are dysgenic in the absence of the CNC. Of special significance in the absence of CNC. Of special significance in the absence of CNC are: 1) the failure of the myocardial sheath to retract; 2) the apparently random distribution of surrogate ectomesenchyme; and 3) the impairment of truncal elastogenesis. These results indicate that the cells of neural crest origin interact with the surrounding mesenchyme during septation and that the entire septation complex depends upon the presence of the neural crest cells for normal development.
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Affiliation(s)
- T H Rosenquist
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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45
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Affiliation(s)
- M L Kirby
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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46
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Icardo JM. Development of the outflow tract. A study in hearts with situs solitus and situs inversus. Ann N Y Acad Sci 1990; 588:26-40. [PMID: 2192644 DOI: 10.1111/j.1749-6632.1990.tb13194.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- J M Icardo
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Cantabria, Santander, Spain
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47
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Rosenquist TH, Beall AC. Elastogenic cells in the developing cardiovascular system. Smooth muscle, nonmuscle, and cardiac neural crest. Ann N Y Acad Sci 1990; 588:106-19. [PMID: 2192637 DOI: 10.1111/j.1749-6632.1990.tb13201.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- T H Rosenquist
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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48
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Leatherbury L, Gauldin HE, Waldo K, Kirby ML. Microcinephotography of the developing heart in neural crest-ablated chick embryos. Circulation 1990; 81:1047-57. [PMID: 2306815 DOI: 10.1161/01.cir.81.3.1047] [Citation(s) in RCA: 33] [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: 12/31/2022]
Abstract
Microcinephotography was used to study heart development in a neural crest model of heart defects, that is, persistent truncus arteriosus, interrupted aortic arch, double outlet right ventricle, or single ventricle and tricuspid valve anomalies. These defects were created in chick embryos by ablation of premigratory neural crest destined for the aorticopulmonary and truncal septa, as well as the third and fourth aortic arch arteries. When embryogenesis reached the looped cardiac tube stage of development (Hamburger-Hamilton stage 18), 19 experimental and 15 control embryos were filmed at 100 frames per second under controlled environmental conditions. Analysis of the microcinephotography films showed the following significant distinguishing characteristics of the developing heart in the experimental embryos: altered conotruncal shape in 100%, depressed contractility and dilation of the primitive ventricle in 84%, decreased emptying of the bulbus cordis in 79%, incompetent truncal cushions in 68%, incomplete looping of the cardiac tube in 58%, and fourth right aortic arch artery without blood flow and third right aortic arch artery with increased flow in 53%. These abnormal characteristics suggested that there were functional and morphological changes in the developing heart of experimental embryos before the time when the predicted structural heart defects would be apparent. It is proposed that the primitive ventricle might attempt to compensate for depressed contractility by ventricular dilation. The incompetent truncal cushions could be secondary to the depressed contractility or secondary to the neural crest ablation that is known to cause persistent truncus arteriosus, an interrupted aortic arch, or both. The absence of blood flow in the right fourth aortic arch artery that will become the definitive aorta correlates with the expected incidence of interrupted aortic arches in this neural crest-ablation model of heart defects. It is speculated that the incomplete looping of the cardiac tube might hinder normal developmental alignment of the outflow and inflow tracts, producing a spectrum of lesions of maldevelopment of the tricuspid valve and dextroposition of the aorta.
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Affiliation(s)
- L Leatherbury
- Department of Pediatrics, Medical College of Georgia, Augusta 30912
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49
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Rosenquist TH, Beall AC, Módis L, Fishman R. Impaired elastic matrix development in the great arteries after ablation of the cardiac neural crest. Anat Rec (Hoboken) 1990; 226:347-59. [PMID: 2183651 DOI: 10.1002/ar.1092260312] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The cells that form the aorticopulmonary septum in the avian embryo have been shown to be similar to the cells that form the walls of the great vessels in two ways: both are derived from the cardiac neural crest and both are able to synthesize an elastogenic matrix in the early embryo. Because of these similarities, and because ablation of the cardiac neural crest causes congenital defects of the outflow tract that are related to failure of proper septation, it was hypothesized that such an ablation also would cause the walls of the great vessels to be defective. The purpose of this study was to compare the elastic matrix in the mediae of the great vessels of normal embryos with those from which the cardiac neural crest had been ablated. The results show that the elastic matrix in the great vessels of the experimental embryos was impaired 1) in the rate of downstream propagation of the initiation of elastogenesis among younger embryos, incubation days 4-8 and 2) in the spatial configuration of the elastic matrix among the older embryos, incubation days 16-20. These results may provide a biological explanation for the elastin defect that affects the pulmonary artery of many patients with cyanotic congenital heart defects.
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Affiliation(s)
- T H Rosenquist
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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50
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Beall AC, Rosenquist TH. Smooth muscle cells of neural crest origin form the aorticopulmonary septum in the avian embryo. Anat Rec (Hoboken) 1990; 226:360-6. [PMID: 2327605 DOI: 10.1002/ar.1092260313] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Previous studies have shown that the cells of the aorticopulmonary (AP) septum are similar to the smooth muscle cells of the mediae of the great vessels in their common origin from the cardiac neural crest and in their common expression of an elastic extracellular matrix. The purpose of this study was to test the cells of the AP septum for the presence of certain cytoplasmic proteins, especially smooth muscle alpha-actin (SMAA) whose presence is definitive of smooth muscle. A monoclonal antibody against SMAA was applied to normal chicken embryos at 3.5-8 days of incubation and to age-matched embryos from which the cardiac neural crest had been ablated surgically. Antibodies against the intermediate filaments desmin, cytokeratin, and vimentin also were applied. The results showed that the AP septal cells expressed SMAA during the process of septation, days 5-8; but when the cardiac neural crest was ablated and septation was defective, no cells in the conotruncal connective tissue expressed SMAA. None of the intermediate filament proteins were detected in the septum. These results indicate that the AP septal cells are smooth muscle and therefore may be hypothesized to have an active role in septation.
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Affiliation(s)
- A C Beall
- Department of Anatomy, Medical College of Georgia, Augusta 30912-2000
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