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Gabriel GC, Lo CW. Molecular Pathways and Animal Models of Defects in Situs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1441:719-738. [PMID: 38884745 DOI: 10.1007/978-3-031-44087-8_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Left-right patterning is among the least well understood of the three axes defining the body plan, and yet it is no less important, with left-right patterning defects causing structural birth defects with high morbidity and mortality, such as complex congenital heart disease, biliary atresia, or intestinal malrotation. The cell signaling pathways governing left-right asymmetry are highly conserved and involve multiple components of the TGF-β superfamily of cell signaling molecules. Central to left-right patterning is the differential activation of Nodal on the left, and BMP signaling on the right. In addition, a plethora of other cell signaling pathways including Shh, FGF, and Notch also contribute to the regulation of left-right patterning. In vertebrate embryos such as the mouse, frog, or zebrafish, the specification of left-right identity requires the left-right organizer (LRO) containing cells with motile and primary cilia that mediate the left-sided propagation of Nodal signaling, followed by left-sided activation of Lefty and then Pitx2, a transcription factor that specifies visceral organ asymmetry. While this overall scheme is well conserved, there are striking species differences, including the finding that motile cilia do not play a role in left-right patterning in some vertebrates. Surprisingly, the direction of heart looping, one of the first signs of organ left-right asymmetry, was recently shown to be specified by intrinsic cell chirality, not Nodal signaling, possibly a reflection of the early origin of Nodal signaling in radially symmetric organisms. How this intrinsic chirality interacts with downstream molecular pathways regulating visceral organ asymmetry will need to be further investigated to elucidate how disturbance in left-right patterning may contribute to complex CHD.
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Affiliation(s)
- George C Gabriel
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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2
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Shaikh Qureshi WM, Hentges KE. Functions of cilia in cardiac development and disease. Ann Hum Genet 2024; 88:4-26. [PMID: 37872827 PMCID: PMC10952336 DOI: 10.1111/ahg.12534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/08/2023] [Accepted: 10/02/2023] [Indexed: 10/25/2023]
Abstract
Errors in embryonic cardiac development are a leading cause of congenital heart defects (CHDs), including morphological abnormalities of the heart that are often detected after birth. In the past few decades, an emerging role for cilia in the pathogenesis of CHD has been identified, but this topic still largely remains an unexplored area. Mouse forward genetic screens and whole exome sequencing analysis of CHD patients have identified enrichment for de novo mutations in ciliary genes or non-ciliary genes, which regulate cilia-related pathways, linking cilia function to aberrant cardiac development. Key events in cardiac morphogenesis, including left-right asymmetric development of the heart, are dependent upon cilia function. Cilia dysfunction during left-right axis formation contributes to CHD as evidenced by the substantial proportion of heterotaxy patients displaying complex CHD. Cilia-transduced signaling also regulates later events during heart development such as cardiac valve formation, outflow tract septation, ventricle development, and atrioventricular septa formation. In this review, we summarize the role of motile and non-motile (primary cilia) in cardiac asymmetry establishment and later events during heart development.
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Affiliation(s)
- Wasay Mohiuddin Shaikh Qureshi
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science CentreUniversity of ManchesterManchesterUK
| | - Kathryn E. Hentges
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science CentreUniversity of ManchesterManchesterUK
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3
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Dong M, Liu J, Liu C, Wang H, Sun W, Liu B. CRISPR/CAS9: A promising approach for the research and treatment of cardiovascular diseases. Pharmacol Res 2022; 185:106480. [PMID: 36191879 DOI: 10.1016/j.phrs.2022.106480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 10/31/2022]
Abstract
The development of gene-editing technology has been one of the biggest advances in biomedicine over the past two decades. Not only can it be used as a research tool to build a variety of disease models for the exploration of disease pathogenesis at the genetic level, it can also be used for prevention and treatment. This is done by intervening with the expression of target genes and carrying out precise molecular targeted therapy for diseases. The simple and flexible clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene-editing technology overcomes the limitations of zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs). For this reason, it has rapidly become a preferred method for gene editing. As a new gene intervention method, CRISPR/Cas9 has been widely used in the clinical treatment of tumours and rare diseases; however, its application in the field of cardiovascular diseases is currently limited. This article reviews the application of the CRISPR/Cas9 editing technology in cardiovascular disease research and treatment, and discusses the limitations and prospects of this technology.
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Affiliation(s)
- Mengying Dong
- Department of Cardiology, The Second Hospital of Jilin University, 218 Ziqiang Road, Changchun, China, 130041
| | - Jiangen Liu
- Department of Cardiology, The Second Hospital of Jilin University, 218 Ziqiang Road, Changchun, China, 130041
| | - Caixia Liu
- Department of Neurology, The Liaoning Province People's Hospital, 33 Wenyi Road, ShenYang, China, 110016
| | - He Wang
- Department of Cardiology, The Second Hospital of Jilin University, 218 Ziqiang Road, Changchun, China, 130041
| | - Wei Sun
- Department of Cardiology, The Second Hospital of Jilin University, 218 Ziqiang Road, Changchun, China, 130041.
| | - Bin Liu
- Department of Cardiology, The Second Hospital of Jilin University, 218 Ziqiang Road, Changchun, China, 130041.
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4
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Little RB, Norris DP. Right, left and cilia: How asymmetry is established. Semin Cell Dev Biol 2021; 110:11-18. [PMID: 32571625 DOI: 10.1016/j.semcdb.2020.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022]
Abstract
The initial breaking of left-right (L-R) symmetry in the embryo is controlled by a motile-cilia-driven leftward fluid flow in the left-right organiser (LRO), resulting in L-R asymmetric gene expression flanking the LRO. Ultimately this results in left- but not right-sided activation of the Nodal-Pitx2 pathway in more lateral tissues. While aspects of the initial breaking event clearly vary between vertebrates, events in the Lateral Plate Mesoderm (LPM) are conserved through the vertebrate lineage. Evidence from model systems and humans highlights the role of cilia both in the initial symmetry breaking and in the ability of more lateral tissues to exhibit asymmetric gene expression. In this review we concentrate on the process of L-R determination in mouse and humans.
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Affiliation(s)
- Rosie B Little
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Dominic P Norris
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK.
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5
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De Ita M, Cisneros B, Rosas-Vargas H. Genetics of Transposition of Great Arteries: Between Laterality Abnormality and Outflow Tract Defect. J Cardiovasc Transl Res 2020; 14:390-399. [PMID: 32734553 DOI: 10.1007/s12265-020-10064-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/24/2020] [Indexed: 12/21/2022]
Abstract
Transposition of great arteries (TGA) is a complex congenital heart disease whose etiology is still unknown. This defect has been associated, at least in part, with genetic abnormalities involved in laterality establishment and heart outflow tract development, which suggest a genetic heterogeneity. In animal models, the evidence of association with certain genes is strong but, surprisingly, genetic anomalies of its human orthologues are found only in a low proportion of patients and in nonaffected subjects, so that the underlying causes remain as an unexplored field. Evidence related to TGA suggests different pathogenic mechanisms involved between patients with normal organ disposition and isomerism. This article reviews the most important genetic abnormalities related to TGA and contextualizes them into the mechanism of embryonic development, comparing them between humans and mice, to comprehend the evidence that could be relevant for genetic counseling. Graphical abstract.
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Affiliation(s)
- Marlon De Ita
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico.,2o Piso Hospital de Pediatría, UMAE Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Unidad de Investigación Médica en Genética Humana, Instituto Mexicano del Seguro Social IMSS, Av. Cuauhtémoc 330, Col Doctores, Delegación Cuauhtémoc, 06720, Mexico City, Mexico
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Haydeé Rosas-Vargas
- 2o Piso Hospital de Pediatría, UMAE Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Unidad de Investigación Médica en Genética Humana, Instituto Mexicano del Seguro Social IMSS, Av. Cuauhtémoc 330, Col Doctores, Delegación Cuauhtémoc, 06720, Mexico City, Mexico.
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6
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Inácio JM, Almeida M, Cristo F, Belo JA. Generation of a gene-corrected human induced pluripotent stem cell line derived from a patient with laterality defects and congenital heart anomalies with a c.455G > A alteration in DAND5. Stem Cell Res 2020; 42:101677. [DOI: 10.1016/j.scr.2019.101677] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 02/02/2023] Open
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Shylo NA, Emmanouil E, Ramrattan D, Weatherbee SD. Loss of ciliary transition zone protein TMEM107 leads to heterotaxy in mice. Dev Biol 2019; 460:187-199. [PMID: 31887266 DOI: 10.1016/j.ydbio.2019.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 11/15/2022]
Abstract
Cilia in most vertebrate left-right organizers are involved in the original break in left-right (L-R) symmetry, however, less is known about their roles in subsequent steps of the cascade - relaying the signaling and maintaining the established asymmetry. Here we describe the L-R patterning cascades in two mutants of a ciliary transition zone protein TMEM107, revealing that near-complete loss of cilia in Tmem107null leads to left pulmonary isomerism due to the failure of the midline barrier. Contrary, partially retained cilia in the node and the midline of a hypomorphic Tmem107schlei mutant appear sufficient for the formation of the midline barrier and establishment and maintenance of the L-R asymmetry. Despite misregulation of Shh signaling in both mutants, the presence of normal Lefty1 expression and midline barrier formation in Tmem107schlei mutants, suggests a requirement for cilia, but not necessarily Shh signaling for Lefty1 expression and midline barrier formation.
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Affiliation(s)
- Natalia A Shylo
- Yale University, Genetics Department, 333 Cedar Street, New Haven, CT, 06510, USA.
| | - Elli Emmanouil
- Yale University, Genetics Department, 333 Cedar Street, New Haven, CT, 06510, USA
| | - Dylan Ramrattan
- Yale University, Genetics Department, 333 Cedar Street, New Haven, CT, 06510, USA
| | - Scott D Weatherbee
- Yale University, Genetics Department, 333 Cedar Street, New Haven, CT, 06510, USA
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8
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Abstract
TGF-β family ligands function in inducing and patterning many tissues of the early vertebrate embryonic body plan. Nodal signaling is essential for the specification of mesendodermal tissues and the concurrent cellular movements of gastrulation. Bone morphogenetic protein (BMP) signaling patterns tissues along the dorsal-ventral axis and simultaneously directs the cell movements of convergence and extension. After gastrulation, a second wave of Nodal signaling breaks the symmetry between the left and right sides of the embryo. During these processes, elaborate regulatory feedback between TGF-β ligands and their antagonists direct the proper specification and patterning of embryonic tissues. In this review, we summarize the current knowledge of the function and regulation of TGF-β family signaling in these processes. Although we cover principles that are involved in the development of all vertebrate embryos, we focus specifically on three popular model organisms: the mouse Mus musculus, the African clawed frog of the genus Xenopus, and the zebrafish Danio rerio, highlighting the similarities and differences between these species.
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Affiliation(s)
- Joseph Zinski
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Benjamin Tajer
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Mary C Mullins
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
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Schweickert A, Ott T, Kurz S, Tingler M, Maerker M, Fuhl F, Blum M. Vertebrate Left-Right Asymmetry: What Can Nodal Cascade Gene Expression Patterns Tell Us? J Cardiovasc Dev Dis 2017; 5:jcdd5010001. [PMID: 29367579 PMCID: PMC5872349 DOI: 10.3390/jcdd5010001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 12/25/2017] [Accepted: 12/25/2017] [Indexed: 11/16/2022] Open
Abstract
Laterality of inner organs is a wide-spread characteristic of vertebrates and beyond. It is ultimately controlled by the left-asymmetric activation of the Nodal signaling cascade in the lateral plate mesoderm of the neurula stage embryo, which results from a cilia-driven leftward flow of extracellular fluids at the left-right organizer. This scenario is widely accepted for laterality determination in wildtype specimens. Deviations from this norm come in different flavors. At the level of organ morphogenesis, laterality may be inverted (situs inversus) or non-concordant with respect to the main body axis (situs ambiguus or heterotaxia). At the level of Nodal cascade gene activation, expression may be inverted, bilaterally induced, or absent. In a given genetic situation, patterns may be randomized or predominantly lacking laterality (absence or bilateral activation). We propose that the distributions of patterns observed may be indicative of the underlying molecular defects, with randomizations being primarily caused by defects in the flow-generating ciliary set-up, and symmetrical patterns being the result of impaired flow sensing, on the left, the right, or both sides. This prediction, the reasoning of which is detailed in this review, pinpoints functions of genes whose role in laterality determination have remained obscure.
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Affiliation(s)
- Axel Schweickert
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Tim Ott
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Sabrina Kurz
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Melanie Tingler
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Markus Maerker
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Franziska Fuhl
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
| | - Martin Blum
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
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The Role of Cerl2 in the Establishment of Left-Right Asymmetries during Axis Formation and Heart Development. J Cardiovasc Dev Dis 2017; 4:jcdd4040023. [PMID: 29367552 PMCID: PMC5753124 DOI: 10.3390/jcdd4040023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 12/13/2022] Open
Abstract
The formation of the asymmetric left-right (LR) body axis is one of the fundamental aspects of vertebrate embryonic development, and one still raising passionate discussions among scientists. Although the conserved role of nodal is unquestionable in this process, several of the details around this signaling cascade are still unanswered. To further understand this mechanism, we have been studying Cerberus-like 2 (Cerl2), an inhibitor of Nodal, and its role in the generation of asymmetries in the early vertebrate embryo. The absence of Cerl2 results in a wide spectrum of malformations commonly known as heterotaxia, which comprises defects in either global organ position (e.g., situs inversus totalis), reversed orientation of at least one organ (e.g., situs ambiguus), and mirror images of usually asymmetric paired organs (e.g., left or right isomerisms of the lungs). Moreover, these laterality defects are frequently associated with congenital heart diseases (e.g., transposition of the great arteries, or atrioventricular septal defects). Here, reviewing the knowledge on the establishment of LR asymmetry in mouse embryos, the emerging conclusion is that as necessary as is the activation of the Nodal signaling cascade, the tight control that Cerl2-mediates on Nodal signaling is equally important, and that generates a further regionalized LR genetic program in the proper time and space.
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Generation of human iPSC line from a patient with laterality defects and associated congenital heart anomalies carrying a DAND5 missense alteration. Stem Cell Res 2017; 25:152-156. [DOI: 10.1016/j.scr.2017.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 10/26/2017] [Indexed: 02/06/2023] Open
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12
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Burdine RD, Grimes DT. Antagonistic interactions in the zebrafish midline prior to the emergence of asymmetric gene expression are important for left-right patterning. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0402. [PMID: 27821532 DOI: 10.1098/rstb.2015.0402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2016] [Indexed: 12/16/2022] Open
Abstract
Left-right (L-R) asymmetry of the internal organs of vertebrates is presaged by domains of asymmetric gene expression in the lateral plate mesoderm (LPM) during somitogenesis. Ciliated L-R coordinators (LRCs) are critical for biasing the initiation of asymmetrically expressed genes, such as nodal and pitx2, to the left LPM. Other midline structures, including the notochord and floorplate, are then required to maintain these asymmetries. Here we report an unexpected role for the zebrafish EGF-CFC gene one-eyed pinhead (oep) in the midline to promote pitx2 expression in the LPM. Late zygotic oep (LZoep) mutants have strongly reduced or absent pitx2 expression in the LPM, but this expression can be rescued to strong levels by restoring oep in midline structures only. Furthermore, removing midline structures from LZoep embryos can rescue pitx2 expression in the LPM, suggesting the midline is a source of an LPM pitx2 repressor that is itself inhibited by oep Reducing lefty1 activity in LZoep embryos mimics removal of the midline, implicating lefty1 in the midline-derived repression. Together, this suggests a model where Oep in the midline functions to overcome a midline-derived repressor, involving lefty1, to allow for the expression of left side-specific genes in the LPM.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Rebecca D Burdine
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Daniel T Grimes
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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Multiple Roles of Pitx2 in Cardiac Development and Disease. J Cardiovasc Dev Dis 2017; 4:jcdd4040016. [PMID: 29367545 PMCID: PMC5753117 DOI: 10.3390/jcdd4040016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 12/14/2022] Open
Abstract
Cardiac development is a complex morphogenetic process initiated as bilateral cardiogenic mesoderm is specified at both sides of the gastrulating embryo. Soon thereafter, these cardiogenic cells fuse at the embryonic midline configuring a symmetrical linear cardiac tube. Left/right bilateral asymmetry is first detected in the forming heart as the cardiac tube bends to the right, and subsequently, atrial and ventricular chambers develop. Molecular signals emanating from the node confer distinct left/right signalling pathways that ultimately lead to activation of the homeobox transcription factor Pitx2 in the left side of distinct embryonic organ anlagen, including the developing heart. Asymmetric expression of Pitx2 has therefore been reported during different cardiac developmental stages, and genetic deletion of Pitx2 provided evidence of key regulatory roles of this transcription factor during cardiogenesis and thus congenital heart diseases. More recently, impaired Pitx2 function has also been linked to arrhythmogenic processes, providing novel roles in the adult heart. In this manuscript, we provide a state-of-the-art review of the fundamental roles of Pitx2 during cardiogenesis, arrhythmogenesis and its contribution to congenital heart diseases.
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14
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Cristo F, Inácio JM, de Almeida S, Mendes P, Martins DS, Maio J, Anjos R, Belo JA. Functional study of DAND5 variant in patients with Congenital Heart Disease and laterality defects. BMC MEDICAL GENETICS 2017; 18:77. [PMID: 28738792 PMCID: PMC5525210 DOI: 10.1186/s12881-017-0444-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/13/2017] [Indexed: 12/22/2022]
Abstract
BACKGROUND Perturbations on the Left-Right axis establishment lead to laterality defects, with frequently associated Congenital Heart Diseases (CHDs). Indeed, in the last decade, it has been reported that the etiology of isolated cases of CHDs or cases of laterality defects with associated CHDs is linked with variants of genes involved in the Nodal signaling pathway. METHODS With this in mind, we analyzed a cohort of 38 unrelated patients with Congenital Heart Defects that can arise from initial perturbations in the formation of the Left-Right axis and 40 unrelated ethnically matched healthy individuals as a control population. Genomic DNA was extracted from buccal epithelial cells, and variants screening was performed by PCR and direct sequencing. A Nodal-dependent luciferase assay was conducted in order to determine the functional effect of the variant found. RESULTS In this work, we report two patients with a DAND5 heterozygous non-synonymous variant (c.455G > A) in the functional domain of the DAND5 protein (p.R152H), a master regulator of Nodal signaling. Patient 1 presents left isomerism, ventricular septal defect with overriding aorta and pulmonary atresia, while patient 2 presents ventricular septal defect with overriding aorta, right ventricular hypertrophy and pulmonary atresia (a case of extreme tetralogy of Fallot phenotype). The functional analysis assay showed a significant decrease in the activity of this variant protein when compared to its wild-type counterpart. CONCLUSION Altogether, our results provide new insight into the molecular mechanism of the laterality defects and related CHDs, priming for the first time DAND5 as one of multiple candidate determinants for CHDs in humans.
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Affiliation(s)
- Fernando Cristo
- Stem Cells and Development Laboratory, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal.,Center for Biomedical Research (CBMR), Universidade do Algarve, Faro, Portugal.,Biomedical Sciences, Universidade do Algarve, Faro, Portugal.,Regenerative Medicine Program, Biomedical and Medicine Sciences Department, Universidade do Algarve, Faro, Portugal
| | - José M Inácio
- Stem Cells and Development Laboratory, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Salomé de Almeida
- Medical Genetics Service, Centro Hospitalar Lisboa Central (CHLC), EPE, Lisboa, Portugal
| | - Patrícia Mendes
- Departamento Materno-Infantil, Centro Hospitalar do Algarve, EPE, Faro, Portugal
| | | | - José Maio
- Departamento Materno-Infantil, Centro Hospitalar do Algarve, EPE, Faro, Portugal
| | - Rui Anjos
- Hospital de Santa Cruz, Centro Hospitalar Lisboa Ocidental, Lisboa, Portugal
| | - José A Belo
- Stem Cells and Development Laboratory, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal. .,NOVA Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Edifício CEDOC II, Rua Câmara Pestana n.° 6, 1150-082, Lisboa, Portugal.
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15
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Current Perspectives in Cardiac Laterality. J Cardiovasc Dev Dis 2016; 3:jcdd3040034. [PMID: 29367577 PMCID: PMC5715725 DOI: 10.3390/jcdd3040034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/23/2016] [Accepted: 12/05/2016] [Indexed: 12/16/2022] Open
Abstract
The heart is the first organ to break symmetry in the developing embryo and onset of dextral looping is the first indication of this event. Looping is a complex process that progresses concomitantly to cardiac chamber differentiation and ultimately leads to the alignment of the cardiac regions in their final topology. Generation of cardiac asymmetry is crucial to ensuring proper form and consequent functionality of the heart, and therefore it is a highly regulated process. It has long been known that molecular left/right signals originate far before morphological asymmetry and therefore can direct it. The use of several animal models has led to the characterization of a complex regulatory network, which invariably converges on the Tgf-β signaling molecule Nodal and its downstream target, the homeobox transcription factor Pitx2. Here, we review current data on the cellular and molecular bases of cardiac looping and laterality, and discuss the contribution of Nodal and Pitx2 to these processes. A special emphasis will be given to the morphogenetic role of Pitx2 and to its modulation of transcriptional and functional properties, which have also linked laterality to atrial fibrillation.
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16
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Grimes DT, Keynton JL, Buenavista MT, Jin X, Patel SH, Kyosuke S, Vibert J, Williams DJ, Hamada H, Hussain R, Nauli SM, Norris DP. Genetic Analysis Reveals a Hierarchy of Interactions between Polycystin-Encoding Genes and Genes Controlling Cilia Function during Left-Right Determination. PLoS Genet 2016; 12:e1006070. [PMID: 27272319 PMCID: PMC4894641 DOI: 10.1371/journal.pgen.1006070] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 04/30/2016] [Indexed: 12/11/2022] Open
Abstract
During mammalian development, left-right (L-R) asymmetry is established by a cilia-driven leftward fluid flow within a midline embryonic cavity called the node. This 'nodal flow' is detected by peripherally-located crown cells that each assemble a primary cilium which contain the putative Ca2+ channel PKD2. The interaction of flow and crown cell cilia promotes left side-specific expression of Nodal in the lateral plate mesoderm (LPM). Whilst the PKD2-interacting protein PKD1L1 has also been implicated in L-R patterning, the underlying mechanism by which flow is detected and the genetic relationship between Polycystin function and asymmetric gene expression remains unknown. Here, we characterize a Pkd1l1 mutant line in which Nodal is activated bilaterally, suggesting that PKD1L1 is not required for LPM Nodal pathway activation per se, but rather to restrict Nodal to the left side downstream of nodal flow. Epistasis analysis shows that Pkd1l1 acts as an upstream genetic repressor of Pkd2. This study therefore provides a genetic pathway for the early stages of L-R determination. Moreover, using a system in which cultured cells are supplied artificial flow, we demonstrate that PKD1L1 is sufficient to mediate a Ca2+ signaling response after flow stimulation. Finally, we show that an extracellular PKD domain within PKD1L1 is crucial for PKD1L1 function; as such, destabilizing the domain causes L-R defects in the mouse. Our demonstration that PKD1L1 protein can mediate a response to flow coheres with a mechanosensation model of flow sensation in which the force of fluid flow drives asymmetric gene expression in the embryo.
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Affiliation(s)
- Daniel T. Grimes
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Jennifer L. Keynton
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Maria T. Buenavista
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
- School of Biological Sciences, University of Reading, Whiteknights, Reading, United Kingdom
- Diamond Light Source, Beamline B23, Chilton, Didcot, United Kingdom
| | - Xingjian Jin
- Chapman University and the University of California, Irvine, Irvine, California, United States of America
| | - Saloni H. Patel
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Shinohara Kyosuke
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University and CREST, Japan Science and Technology Corporation (JST), Suita, Japan
| | - Jennifer Vibert
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Debbie J. Williams
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Hiroshi Hamada
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University and CREST, Japan Science and Technology Corporation (JST), Suita, Japan
| | - Rohanah Hussain
- Diamond Light Source, Beamline B23, Chilton, Didcot, United Kingdom
| | - Surya M. Nauli
- Chapman University and the University of California, Irvine, Irvine, California, United States of America
| | - Dominic P. Norris
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
- * E-mail:
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17
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Melanocytes Affect Nodal Expression and Signaling in Melanoma Cells: A Lesson from Pediatric Large Congenital Melanocytic Nevi. Int J Mol Sci 2016; 17:418. [PMID: 27011171 PMCID: PMC4813269 DOI: 10.3390/ijms17030418] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 12/27/2022] Open
Abstract
Expression of Nodal, a Transforming Growth Factor-beta (TGF-β) related growth factor, is associated with aggressive melanoma. Nodal expression in adult dysplastic nevi may predict the development of aggressive melanoma in some patients. A subset of pediatric patients diagnosed with giant or large congenital melanocytic nevi (LCMN) has shown increased risk for development of melanoma. Here, we investigate whether Nodal expression can help identify the rare cases of LCMN that develop melanoma and shed light on why the majority of these patients do not. Immunohistochemistry (IHC) staining results show varying degree of Nodal expression in pediatric dysplastic nevi and LCMN. Moreover, median scores from Nodal IHC expression analysis were not significantly different between these two groups. Additionally, none of the LCMN patients in this study developed melanoma, regardless of Nodal IHC levels. Co-culture experiments revealed reduced tumor growth and lower levels of Nodal and its signaling molecules P-SMAD2 and P-ERK1/2 when melanoma cells were grown in vivo or in vitro with normal melanocytes. The same was observed in melanoma cells cultured with melanocyte conditioned media containing pigmented melanocyte derived melanosomes (MDM). Since MDM contain molecules capable of inactivating radical oxygen species, to investigate potential anti-oxidant effect of MDM on Nodal expression and signaling in melanoma, melanoma cells were treated with either N-acetyl-l-cysteine (NAC), a component of the anti-oxidant glutathione or synthetic melanin, which in addition to providing pigmentation can also exert free radical scavenging activity. Melanoma cells treated with NAC or synthetic melanin showed reduced levels of Nodal, P-SMAD2 and P-ERK1/2 compared to untreated melanoma cells. Thus, the potential role for Nodal in melanoma development in LCMN is less evident than in adult dysplastic nevi possibly due to melanocyte cross-talk in LCMN capable of offsetting or delaying the pro-melanoma effects of Nodal via anti-oxidant effects of MDM.
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Soukup V, Yong LW, Lu TM, Huang SW, Kozmik Z, Yu JK. The Nodal signaling pathway controls left-right asymmetric development in amphioxus. EvoDevo 2015; 6:5. [PMID: 25954501 PMCID: PMC4423147 DOI: 10.1186/2041-9139-6-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/27/2015] [Indexed: 11/24/2022] Open
Abstract
Background Nodal is an important determinant of the left-right (LR) body axis in bilaterians, specifying the right side in protostomes and non-chordate deuterostomes as opposed to the left side in chordates. Amphioxus represents an early-branching chordate group, rendering it especially useful for studying the character states that predate the origin of vertebrates. However, its anatomy, involving offset arrangement of axial structures, marked asymmetry of the oropharyngeal region, and, most notably, a mouth positioned on the left side, contrasts with the symmetric arrangement of the corresponding regions in other chordates. Results We show that the Nodal signaling pathway acts to specify the LR axis in the cephalochordate amphioxus in a similar way as in vertebrates. At early neurula stages, Nodal switches from initial bilateral to the left-sided expression and subsequently specifies the left embryonic side. Perturbation of Nodal signaling with small chemical inhibitors (SB505124 and SB431542) alters expression of other members of the pathway and of left/right-sided, organ-specific genes. Upon inhibition, larvae display loss of the innate alternation of both somites and axons of peripheral nerves and loss of left-sided pharyngeal structures, such as the mouth, the preoral pit, and the duct of the club-shaped gland. Concomitantly, the left side displays ectopic expression of otherwise right-sided genes, and the larvae exhibit bilaterally symmetrical morphology, with duplicated endostyle and club-shaped gland structures. Conclusions We demonstrate that Nodal signaling is necessary for establishing the LR embryonic axis and for developing profound asymmetry in amphioxus. Our data suggest that initial symmetry breaking in amphioxus and propagation of the pathway on the left side correspond with the situation in vertebrates. However, the organs that become targets of the pathway differ between amphioxus and vertebrates, which may explain the pronounced asymmetry of its oropharyngeal and axial structures and the left-sided position of the mouth. Electronic supplementary material The online version of this article (doi:10.1186/2041-9139-6-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vladimir Soukup
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague, 14220 Czech Republic
| | - Luok Wen Yong
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 Taiwan
| | - Tsai-Ming Lu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 Taiwan
| | - Song-Wei Huang
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 Taiwan
| | - Zbynek Kozmik
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague, 14220 Czech Republic
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529 Taiwan ; Institute of Oceanography, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, 10617 Taiwan
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19
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Hamada H, Tam PP. Mechanisms of left-right asymmetry and patterning: driver, mediator and responder. F1000PRIME REPORTS 2014; 6:110. [PMID: 25580264 PMCID: PMC4275019 DOI: 10.12703/p6-110] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The establishment of a left-right (LR) organizer in the form of the ventral node is an absolute prerequisite for patterning the tissues on contralateral sides of the body of the mouse embryo. The experimental findings to date are consistent with a mechanistic paradigm that the laterality information, which is generated in the ventral node, elicits asymmetric molecular activity and cellular behaviour in the perinodal tissues. This information is then relayed to the cells in the lateral plate mesoderm (LPM) when the left-specific signal is processed and translated into LR body asymmetry. Here, we reflect on our current knowledge and speculate on the following: (a) what are the requisite anatomical and functional attributes of an LR organizer, (b) what asymmetric information is emanated from this organizer, and (c) how this information is transferred across the paraxial tissue compartment and elicits a molecular response specifically in the LPM.
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Affiliation(s)
- Hiroshi Hamada
- Developmental Genetics Group, Graduate School of Frontier Bioscience, Osaka UniversityJapan
| | - Patrick P.L. Tam
- Embryology Unit, Children's Medical Research Institute and Sydney Medical School, University of SydneyNew South WalesAustralia
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20
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TGFβ signaling in establishing left–right asymmetry. Semin Cell Dev Biol 2014; 32:80-4. [DOI: 10.1016/j.semcdb.2014.03.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 03/26/2014] [Indexed: 11/19/2022]
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21
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Araújo AC, Marques S, Belo JA. Targeted inactivation of Cerberus like-2 leads to left ventricular cardiac hyperplasia and systolic dysfunction in the mouse. PLoS One 2014; 9:e102716. [PMID: 25033293 PMCID: PMC4102536 DOI: 10.1371/journal.pone.0102716] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/23/2014] [Indexed: 11/29/2022] Open
Abstract
Previous analysis of the Cerberus like 2 knockout (Cerl2−/−) mouse revealed a significant mortality during the first day after birth, mostly due to cardiac defects apparently associated with randomization of the left-right axis. We have however, identified Cerl2-associated cardiac defects, particularly a large increase in the left ventricular myocardial wall in neonates that cannot be explained by laterality abnormalities. Therefore, in order to access the endogenous role of Cerl2 in cardiogenesis, we analyzed the embryonic and neonatal hearts of Cerl2 null mutants that did not display a laterality phenotype. Neonatal mutants obtained from the compound mouse line Cer2−/−::Mlc1v-nLacZ24+, in which the pulmonary ventricle is genetically marked, revealed a massive enlargement of the ventricular myocardium in animals without laterality defects. Echocardiography analysis in Cerl2−/− neonates showed a left ventricular systolic dysfunction that is incompatible with a long lifespan. We uncovered that the increased ventricular muscle observed in Cerl2−/− mice is caused by a high cardiomyocyte mitotic index in the compact myocardium which is mainly associated with increased Ccnd1 expression levels in the left ventricle at embryonic day (E) 13. Interestingly, at this stage we found augmented left ventricular expression of Cerl2 levels when compared with the right ventricle, which may elucidate the regionalized contribution of Cerl2 to the left ventricular muscle formation. Importantly, we observed an increase of phosphorylated Smad2 (pSmad2) levels in embryonic (E13) and neonatal hearts indicating a prolonged TGFβs/Nodal-signaling activation. Concomitantly, we detected an increase of Baf60c levels, but only in Cerl2−/− embryonic hearts. These results indicate that independently of its well-known role in left-right axis establishment Cerl2 plays an important role during heart development in the mouse, mediating Baf60c levels by exerting an important control of the TGFβs/Nodal-signaling pathway.
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Affiliation(s)
- Ana Carolina Araújo
- Laboratory of Embryology and Genetic Manipulation, Regenerative Medicine Program, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- IBB - Institute for Biotechnology and Bioengineering, Centro de Biomedicina Molecular e Estrutural, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- PhD Program in Biomedical Sciences, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Sara Marques
- Laboratory of Embryology and Genetic Manipulation, Regenerative Medicine Program, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- IBB - Institute for Biotechnology and Bioengineering, Centro de Biomedicina Molecular e Estrutural, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - José António Belo
- Laboratory of Embryology and Genetic Manipulation, Regenerative Medicine Program, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- IBB - Institute for Biotechnology and Bioengineering, Centro de Biomedicina Molecular e Estrutural, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
- CEDOC – Chronic Diseases Research Center, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
- * E-mail:
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22
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Abstract
Many aspects of heart development are determined by the left right axis and as a result several congenital diseases have their origins in aberrant left-right patterning. Establishment of this axis occurs early in embryogenesis before formation of the linear heart tube yet impacts upon much later morphogenetic events. In this review I discuss the differing mechanisms by which left-right polarity is achieved in the mouse and chick embryos and comment on the evolution of this system. I then discus three major classes of cardiovascular defect associated with aberrant left-right patterning seen in mouse mutants and human disease. I describe phenotypes associated with the determination of atrial identity and venous connections, looping morphogenesis of the heart tube and finally the asymmetric remodelling of the embryonic branchial arch arterial system to form the leftward looped arch of aorta and associated great arteries. Where appropriate, I consider left right patterning defects from an evolutionary perspective, demonstrating how developmental processes have been modified in species over time and illustrating how comparative embryology can aide in our understanding of congenital heart disease.
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Affiliation(s)
- Iain M Dykes
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN, UK
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23
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Abstract
Many internal organs develop distinct left and right sides that are essential for their functions. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that plays an important role in establishing left-right (LR) signaling cascades. These ‘LR cilia’ are found in the ventral node and posterior notochordal plate in mammals, the gastrocoel roof plate in amphibians and Kupffer’s vesicle in teleost fish. I consider these transient ciliated structures as the ‘organ of asymmetry’ that directs LR patterning of the developing embryo. Variations in size and morphology of the organ of asymmetry in different vertebrate species have raised questions regarding the fundamental features that are required for LR determination. Here, I review current models for how LR asymmetry is established in vertebrates, discuss the cellular architecture of the ciliated organ of asymmetry and then propose key features of this organ that are critical for orienting the LR body axis.
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Affiliation(s)
- Jeffrey D Amack
- Department of Cell and Developmental Biology; State University of New York; Upstate Medical University; Syracuse, NY USA
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24
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Superina S, Borovina A, Ciruna B. Analysis of maternal-zygotic ugdh mutants reveals divergent roles for HSPGs in vertebrate embryogenesis and provides new insight into the initiation of left-right asymmetry. Dev Biol 2014; 387:154-66. [PMID: 24462977 DOI: 10.1016/j.ydbio.2014.01.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/20/2013] [Accepted: 01/14/2014] [Indexed: 11/25/2022]
Abstract
Growth factors and morphogens regulate embryonic patterning, cell fate specification, cell migration, and morphogenesis. The activity and behavior of these signaling molecules are regulated in the extracellular space through interactions with proteoglycans (Bernfield et al., 1999; Perrimon and Bernfield 2000; Lander and Selleck 2000; Selleck 2000). Proteoglycans are high molecular-weight proteins consisting of a core protein with covalently linked glycosaminoglycan (GAG) side chains, which are thought to mediate ligand interaction. Drosophila mutant embryos deficient for UDP-glucose dehydrogenase activity (Ugdh, required for GAG synthesis) exhibit abnormal Fgf, Wnt and TGFß signaling and die during gastrulation, indicating a broad and critical role for proteoglycans during early embryonic development (Lin et al., 1999; Lin and Perrimon 2000) (Hacker et al., 1997). Mouse Ugdh mutants also die at gastrulation, however, only Fgf signaling appears disrupted (Garcia-Garcia and Anderson, 2003). These findings suggested a possible divergence in the requirement for proteoglycans during Drosophila and mouse embryogenesis, and that mammals may have evolved alternative means of regulating Wnt and TGFß activity. To further examine the function of proteoglycans in vertebrate development, we have characterized zebrafish mutants devoid of both maternal and zygotic Ugdh/Jekyll activity (MZjekyll). We demonstrate that MZjekyll mutant embryos display abnormal Fgf, Shh, and Wnt signaling activities, with concomitant defects in central nervous system patterning, cardiac ventricular fate specification and axial morphogenesis. Furthermore, we uncover a novel role for proteoglycans in left-right pattern formation. Our findings resolve longstanding questions into the evolutionary conservation of Ugdh function and provide new mechanistic insights into the initiation of left-right asymmetry.
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Affiliation(s)
- Simone Superina
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8
| | - Antonia Borovina
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8
| | - Brian Ciruna
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, Ont., Canada M5G 1X8; Department of Molecular Genetics, The University of Toronto, Toronto, Ont., Canada M5S 1A8.
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25
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Abstract
The satellite symposium on 'Making and breaking the left-right axis: implications of laterality in development and disease' was held in June 2013 in conjunction with the 17th International Society for Developmental Biology meeting in Cancún, Mexico. As we summarize here, leaders in the field gathered at the symposium to discuss recent advances in understanding how left-right asymmetry is generated and utilized across the animal kingdom.
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Affiliation(s)
- Rebecca D Burdine
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
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26
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Roles of cilia, fluid flow, and Ca2+ signaling in breaking of left-right symmetry. Trends Genet 2013; 30:10-7. [PMID: 24091059 DOI: 10.1016/j.tig.2013.09.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/18/2013] [Accepted: 09/03/2013] [Indexed: 11/23/2022]
Abstract
The emergence of left-right (L-R) asymmetry during embryogenesis is a classic problem in developmental biology. It is only since the 1990s, however, that substantial insight into this problem has been achieved by molecular and genetic approaches. Various genes required for L-R asymmetric morphogenesis in vertebrates have now been identified, and many of these genes are required for the formation and motility of cilia. Breaking of L-R symmetry in the mouse embryo occurs in the ventral node, where two types of cilia are present. Whereas centrally located motile cilia generate a leftward fluid flow, peripherally located immotile cilia sense a flow-dependent signal, which is either chemical or mechanical in nature. Although Ca2+ signaling is implicated in flow sensing, the precise mechanism remains unknown. Here we summarize current knowledge of L-R symmetry breaking in vertebrates (focusing on the mouse), with a special emphasis on the roles of cilia, fluid flow, and Ca2+ signaling.
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