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Notenboom ML, Van Hoof L, Schuermans A, Takkenberg JJM, Rega FR, Taverne YJHJ. Aortic Valve Embryology, Mechanobiology, and Second Messenger Pathways: Implications for Clinical Practice. J Cardiovasc Dev Dis 2024; 11:49. [PMID: 38392263 PMCID: PMC10888685 DOI: 10.3390/jcdd11020049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 01/22/2024] [Accepted: 01/29/2024] [Indexed: 02/24/2024] Open
Abstract
During the Renaissance, Leonardo Da Vinci was the first person to successfully detail the anatomy of the aortic root and its adjacent structures. Ever since, novel insights into morphology, function, and their interplay have accumulated, resulting in advanced knowledge on the complex functional characteristics of the aortic valve (AV) and root. This has shifted our vision from the AV as being a static structure towards that of a dynamic interconnected apparatus within the aortic root as a functional unit, exhibiting a complex interplay with adjacent structures via both humoral and mechanical stimuli. This paradigm shift has stimulated surgical treatment strategies of valvular disease that seek to recapitulate healthy AV function, whereby AV disease can no longer be seen as an isolated morphological pathology which needs to be replaced. As prostheses still cannot reproduce the complexity of human nature, treatment of diseased AVs, whether stenotic or insufficient, has tremendously evolved, with a similar shift towards treatments options that are more hemodynamically centered, such as the Ross procedure and valve-conserving surgery. Native AV and root components allow for an efficient Venturi effect over the valve to allow for optimal opening during the cardiac cycle, while also alleviating the left ventricle. Next to that, several receptors are present on native AV leaflets, enabling messenger pathways based on their interaction with blood and other shear-stress-related stimuli. Many of these physiological and hemodynamical processes are under-acknowledged but may hold important clues for innovative treatment strategies, or as potential novel targets for therapeutic agents that halt or reverse the process of valve degeneration. A structured overview of these pathways and their implications for cardiothoracic surgeons and cardiologists is lacking. As such, we provide an overview on embryology, hemodynamics, and messenger pathways of the healthy and diseased AV and its implications for clinical practice, by relating this knowledge to current treatment alternatives and clinical decision making.
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Affiliation(s)
- Maximiliaan L. Notenboom
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; (M.L.N.)
| | - Lucas Van Hoof
- Department of Cardiac Surgery, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Art Schuermans
- Department of Cardiac Surgery, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Johanna J. M. Takkenberg
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; (M.L.N.)
| | - Filip R. Rega
- Department of Cardiac Surgery, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Yannick J. H. J. Taverne
- Department of Cardiothoracic Surgery, Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; (M.L.N.)
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Sleiman AK, Sadder L, Nemer G. Human Genetics of Tricuspid Atresia and Univentricular Heart. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1441:875-884. [PMID: 38884756 DOI: 10.1007/978-3-031-44087-8_54] [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
Tricuspid atresia (TA) is a rare congenital heart condition that presents with a complete absence of the right atrioventricular valve. Because of the rarity of familial and/or isolated cases of TA, little is known about the potential genetic abnormalities contributing to this condition. Potential responsible chromosomal abnormalities were identified in exploratory studies and include deletions in 22q11, 4q31, 8p23, and 3p as well as trisomies 13 and 18. In parallel, potential culprit genes include the ZFPM2, HEY2, NFATC1, NKX2-5, MYH6, and KLF13 genes. The aim of this chapter is to expose the genetic components that are potentially involved in the pathogenesis of TA in humans. The large variability in phenotypes and genotypes among cases of TA suggests a genetic network that involves many components yet to be unraveled.
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Affiliation(s)
| | - Liane Sadder
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - George Nemer
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
- College of Health and Life Sciences, Hamad bin Khalifa University, Doha, Qatar.
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Tang Q, McNair AJ, Phadwal K, Macrae VE, Corcoran BM. The Role of Transforming Growth Factor-β Signaling in Myxomatous Mitral Valve Degeneration. Front Cardiovasc Med 2022; 9:872288. [PMID: 35656405 PMCID: PMC9152029 DOI: 10.3389/fcvm.2022.872288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/12/2022] [Indexed: 02/03/2023] Open
Abstract
Mitral valve prolapse (MVP) due to myxomatous degeneration is one of the most important chronic degenerative cardiovascular diseases in people and dogs. It is a common cause of heart failure leading to significant morbidity and mortality in both species. Human MVP is usually classified into primary or non-syndromic, including Barlow’s Disease (BD), fibro-elastic deficiency (FED) and Filamin-A mutation, and secondary or syndromic forms (typically familial), such as Marfan syndrome (MFS), Ehlers-Danlos syndrome, and Loeys–Dietz syndrome. Despite different etiologies the diseased valves share pathological features consistent with myxomatous degeneration. To reflect this common pathology the condition is often called myxomatous mitral valve degeneration (disease) (MMVD) and this term is universally used to describe the analogous condition in the dog. MMVD in both species is characterized by leaflet thickening and deformity, disorganized extracellular matrix, increased transformation of the quiescent valve interstitial cell (qVICs) to an activated state (aVICs), also known as activated myofibroblasts. Significant alterations in these cellular activities contribute to the initiation and progression of MMVD due to the increased expression of transforming growth factor-β (TGF-β) superfamily cytokines and the dysregulation of the TGF-β signaling pathways. Further understanding the molecular mechanisms of MMVD is needed to identify pharmacological manipulation strategies of the signaling pathway that might regulate VIC differentiation and so control the disease onset and development. This review briefly summarizes current understanding of the histopathology, cellular activities, molecular mechanisms and pathogenesis of MMVD in dogs and humans, and in more detail reviews the evidence for the role of TGF-β.
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Affiliation(s)
- Qiyu Tang
- The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew J. McNair
- The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Kanchan Phadwal
- The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Vicky E. Macrae
- The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Brendan M. Corcoran
- The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh, United Kingdom
- *Correspondence: Brendan M. Corcoran,
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Farrar EJ, Hiriart E, Mahmut A, Jagla B, Peal DS, Milan DJ, Butcher JT, Puceat M. OCT4-mediated inflammation induces cell reprogramming at the origin of cardiac valve development and calcification. SCIENCE ADVANCES 2021; 7:eabf7910. [PMID: 34739324 PMCID: PMC8570594 DOI: 10.1126/sciadv.abf7910] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Cell plasticity plays a key role in embryos by maintaining the differentiation potential of progenitors. Whether postnatal somatic cells revert to an embryonic-like naïve state regaining plasticity and redifferentiate into a cell type leading to a disease remains intriguing. Using genetic lineage tracing and single-cell RNA sequencing, we reveal that Oct4 is induced by nuclear factor κB (NFκB) at embyronic day 9.5 in a subset of mouse endocardial cells originating from the anterior heart forming field at the onset of endocardial-to-mesenchymal transition. These cells acquired a chondro-osteogenic fate. OCT4 in adult valvular aortic cells leads to calcification of mouse and human valves. These calcifying cells originate from the Oct4 embryonic lineage. Genetic deletion of Pou5f1 (Pit-Oct-Unc, OCT4) in the endocardial cell lineage prevents aortic stenosis and calcification of ApoE−/− mouse valve. We established previously unidentified self-cell reprogramming NFκB- and OCT4-mediated inflammatory pathway triggering a dose-dependent mechanism of valve calcification.
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Affiliation(s)
- Emily J. Farrar
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Emilye Hiriart
- INSERM U1251, Aix-Marseille University, MMG, Marseille, France
| | - Ablajan Mahmut
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Bernd Jagla
- Pasteur Institute, Cytometry and Biomarkers Unit of Technology and Service, C2RT, & Hub de Bioinformatique et Biostatistique–Département Biologie Computationnelle, Paris, France
| | - David S. Peal
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA
| | - David J. Milan
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA 02114, USA
| | - Jonathan T. Butcher
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
- Corresponding author. (M.P.); (J.B.)
| | - Michel Puceat
- INSERM U1251, Aix-Marseille University, MMG, Marseille, France
- Corresponding author. (M.P.); (J.B.)
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Ridge LA, Kewbank D, Schütz D, Stumm R, Scambler PJ, Ivins S. Dual role for CXCL12 signaling in semilunar valve development. Cell Rep 2021; 36:109610. [PMID: 34433040 PMCID: PMC8411116 DOI: 10.1016/j.celrep.2021.109610] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 04/29/2021] [Accepted: 08/05/2021] [Indexed: 01/10/2023] Open
Abstract
Cxcl12-null embryos have dysplastic, misaligned, and hyperplastic semilunar valves (SLVs). In this study, we show that CXCL12 signaling via its receptor CXCR4 fulfills distinct roles at different stages of SLV development, acting initially as a guidance cue to pattern cellular distribution within the valve primordia during the endocardial-to-mesenchymal transition (endoMT) phase and later regulating mesenchymal cell proliferation during SLV remodeling. Transient, anteriorly localized puncta of internalized CXCR4 are observed in cells undergoing endoMT. In vitro, CXCR4+ cell orientation in response to CXCL12 requires phosphatidylinositol 3-kinase (PI3K) signaling and is inhibited by suppression of endocytosis. This dynamic intracellular localization of CXCR4 during SLV development is related to CXCL12 availability, potentially enabling activation of divergent downstream signaling pathways at key developmental stages. Importantly, Cxcr7-/- mutants display evidence of excessive CXCL12 signaling, indicating a likely role for atypical chemokine receptor CXCR7 in regulating ligand bioavailability and thus CXCR4 signaling output during SLV morphogenesis.
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Affiliation(s)
- Liam A Ridge
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Dania Kewbank
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Dagmar Schütz
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena 07747, Germany
| | - Ralf Stumm
- Institute of Pharmacology and Toxicology, Jena University Hospital, Friedrich Schiller University Jena, Jena 07747, Germany
| | - Peter J Scambler
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Sarah Ivins
- Developmental Biology of Birth Defects, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Dolmatov IY, Kalacheva NV, Tkacheva ES, Shulga AP, Zavalnaya EG, Shamshurina EV, Girich AS, Boyko AV, Eliseikina MG. Expression of Piwi, MMP, TIMP, and Sox during Gut Regeneration in Holothurian Eupentacta fraudatrix (Holothuroidea, Dendrochirotida). Genes (Basel) 2021; 12:1292. [PMID: 34440466 PMCID: PMC8391186 DOI: 10.3390/genes12081292] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023] Open
Abstract
Mesodermal cells of holothurian Eupentacta fraudatrix can transdifferentiate into enterocytes during the regeneration of the digestive system. In this study, we investigated the expression of several genes involved in gut regeneration in E. fraudatrix. Moreover, the localization of progenitor cells of coelomocytes, juvenile cells, and their participation in the formation of the luminal epithelium of the digestive tube were studied. It was shown that Piwi-positive cells were not involved in the formation of the luminal epithelium of the digestive tube. Ef-72 kDa type IV collagenase and Ef-MMP16 had an individual expression profile and possibly different functions. The Ef-tensilin3 gene exhibited the highest expression and indicates its potential role in regeneration. Ef-Sox9/10 and Ef-Sox17 in E. fraudatrix may participate in the mechanism of transdifferentiation of coelomic epithelial cells. Their transcripts mark the cells that plunge into the connective tissue of the gut anlage and give rise to enterocytes. Ef-Sox9/10 probably controls the switching of mesodermal cells to the enterocyte phenotype, while Ef-Sox17 may be involved in the regulation of the initial stages of transdifferentiation.
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Affiliation(s)
- Igor Yu. Dolmatov
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Palchevsky 17, 690041 Vladivostok, Russia; (N.V.K.); (E.S.T.); (A.P.S.); (E.G.Z.); (E.V.S.); (A.S.G.); (A.V.B.); (M.G.E.)
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7
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Li B, Li T, Pu T, Liu C, Chen S, Sun K, Xu R. Genetic and functional analyses detect one pathological NFATC1 mutation in a Chinese tricuspid atresia family. Mol Genet Genomic Med 2021; 9:e1771. [PMID: 34363434 PMCID: PMC8457709 DOI: 10.1002/mgg3.1771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/04/2020] [Accepted: 07/09/2021] [Indexed: 11/24/2022] Open
Abstract
Background Cardiac valvulogenesis is a highly conserved process among vertebrates and cause unidirectional flow of blood in the heart. It was precisely regulated by signal pathways such as VEGF, NOTCH, and WNT and transcriptional factors such as TWIST1, TBX20, NFATC1, and SOX9. Tricuspid atresia refers to morphological deficiency of the valve and confined right atrioventricular traffic due to tricuspid maldevelopment, and is one of the most common types of congenital valve defects. Methods We recruited a healthy couple with two fetuses aborted due to tricuspid atresia and identified related gene mutations using whole‐exome sequencing. We then discussed the pathogenic significance of this mutation by bioinformatic and functional analyses. Results PROVEAN, PolyPhen, MutationTaster, and HOPE indicated the mutation could change the protein function and cause disease; Western blotting showed the expression of NFATC1 c.964G>A mutation was lower than the wild type. What's more, dual‐luciferase reporter assay showed the transcriptional activity of NFATC1 was impact by mutation and the expression of downstream DEGS1 was influenced. Conclusion Taken together, the c.964G>A mutation might be pathological and related to the occurrence of disease. Our research tended to deepen the understanding of etiology of tricuspid atresia and gene function of NFATC1, and provide some references or suggestions for genetic diagnosis of tricuspid atresia.
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Affiliation(s)
- Bojian Li
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Tingting Li
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Tian Pu
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chunjie Liu
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Sun Chen
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Kun Sun
- Department of Pediatric Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Rang Xu
- Scientific Research Center, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Dutta P, Kodigepalli KM, LaHaye S, Thompson JW, Rains S, Nagel C, Thatcher K, Hinton RB, Lincoln J. KPT-330 Prevents Aortic Valve Calcification via a Novel C/EBPβ Signaling Pathway. Circ Res 2021; 128:1300-1316. [PMID: 33601919 PMCID: PMC8085092 DOI: 10.1161/circresaha.120.318503] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Punashi Dutta
- Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Pediatric Cardiology, The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI, USA
| | - Karthik M. Kodigepalli
- Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Pediatric Cardiology, The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI, USA
| | - Stephanie LaHaye
- The Institute for Genomic Medicine at Nationwide Children’s Hospital, Columbus, OH, USA
| | - J. Will Thompson
- Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
| | - Sarah Rains
- Pharmacology and Cancer Biology, Duke University, Durham, NC, USA
- Duke Proteomics and Metabolomics Shared Resource, Durham, NC, USA
| | - Casey Nagel
- Ocean Ridge Biosciences, Deerfield Beach, Florida, USA
| | - Kaitlyn Thatcher
- Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Pediatric Cardiology, The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI, USA
| | - Robert B. Hinton
- Division of Molecular Cardiovascular Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Joy Lincoln
- Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
- Pediatric Cardiology, The Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI, USA
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Guo L, Glover J, Risner A, Wang C, Fulmer D, Moore K, Gensemer C, Rumph MK, Moore R, Beck T, Norris RA. Dynamic Expression Profiles of β-Catenin during Murine Cardiac Valve Development. J Cardiovasc Dev Dis 2020; 7:jcdd7030031. [PMID: 32824435 PMCID: PMC7570242 DOI: 10.3390/jcdd7030031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 12/14/2022] Open
Abstract
β-catenin has been widely studied in many animal and organ systems across evolution, and gain or loss of function has been linked to a number of human diseases. Yet fundamental knowledge regarding its protein expression and localization remains poorly described. Thus, we sought to define whether there was a temporal and cell-specific regulation of β-catenin activities that correlate with distinct cardiac morphological events. Our findings indicate that activated nuclear β-catenin is primarily evident early in gestation. As development proceeds, nuclear β-catenin is down-regulated and becomes restricted to the membrane in a subset of cardiac progenitor cells. After birth, little β-catenin is detected in the heart. The co-expression of β-catenin with its main transcriptional co-factor, Lef1, revealed that Lef1 and β-catenin expression domains do not extensively overlap in the cardiac valves. These data indicate mutually exclusive roles for Lef1 and β-catenin in most cardiac cell types during development. Additionally, these data indicate diverse functions for β-catenin within the nucleus and membrane depending on cell type and gestational timing. Cardiovascular studies should take into careful consideration both nuclear and membrane β-catenin functions and their potential contributions to cardiac development and disease.
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Abstract
Tricuspid atresia (TA) is a complex congenital heart disease that presents with cyanosis in the neonatal period. It is invariably fatal if left untreated and requires multiple stages of palliation. Early recognition and timely surgical intervention are therefore pivotal in the management of these infants. This literature review considers the pathophysiology, presentation, investigations, and classification of TA. Moreover, it discusses the evidence upon which the latest medical and surgical treatments are based, as well as numerous recent case reports. Further work is needed to elucidate the etiology of TA, clarify the role of pharmacotherapy, and optimize the surgical management that these patients receive.
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Affiliation(s)
- Anoop S Sumal
- School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Harry Kyriacou
- School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | - Ahmed M H A M Mostafa
- School of Clinical Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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Nozari A, Aghaei-Moghadam E, Zeinaloo A, Alavi A, Ghasemi Firouzabdi S, Minaee S, Eskandari Hesari M, Behjati F. A Pathogenic Homozygous Mutation in The Pleckstrin Homology Domain of RASA1 Is Responsible for Familial Tricuspid Atresia in An Iranian Consanguineous Family. CELL JOURNAL 2018; 21:70-77. [PMID: 30507091 PMCID: PMC6275424 DOI: 10.22074/cellj.2019.5734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/21/2018] [Indexed: 11/28/2022]
Abstract
Objective Tricuspid atresia (TA) is a rare life-threatening form of congenital heart defect (CHD). The genetic
mechanisms underlying TA are not clearly understood. According to previous studies, the endocardial cushioning event,
as the primary sign of cardiac valvulogenesis, is governed by several overlapping signaling pathways including Ras/
ERK pathway. RASA1, a regulator of cardiovascular development, is involved in this pathway and its haploinsufficiency
(due to heterozygous mutations) has been identified as the underlying etiology of the autosomal dominant capillary
malformation/arteriovenous malformation (CM/AVM).
Materials and Methods In this prospective study, we used whole exome sequencing (WES) followed by serial
bioinformatics filtering steps for two siblings with TA and early onset CM. Their parents were consanguineous which
had a history of recurrent abortions. Patients were carefully assessed to exclude extra-cardiac anomalies.
Results We identified a homozygous RASA1 germline mutation, c.1583A>G (p.Tyr528Cys) in the family. This mutation
lies in the pleckstrin homology (PH) domain of the gene. The parents who were heterozygous for this variant displayed
CM.
Conclusion This is the first study reporting an adverse phenotypic outcome of a RASA1 homozygous mutation.
Here, we propose that the phenotypic consequence of the homozygous RASA1 p.Tyr528Cys mutation is more serious
than the heterozygous type. This could be responsible for the TA pathogenesis in our patients. We strongly suggest
that parents with CM/AVM should be investigated for RASA1 heterozygous mutations. Prenatal diagnosis and fetal
echocardiography should also be carried out in the event of pregnancy in heterozygous parents.
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Affiliation(s)
- Ahoura Nozari
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Ehsan Aghaei-Moghadam
- Department of Pediatrics Cardiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Aliakbar Zeinaloo
- Department of Pediatrics Cardiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Afagh Alavi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | | | - Shohre Minaee
- Department of Pediatrics Cardiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Eskandari Hesari
- Department of Pediatrics Cardiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Farkhondeh Behjati
- Department of Pediatrics Cardiology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Electronic Address:
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Identification of circular RNAs in human aortic valves. Gene 2018; 642:135-144. [DOI: 10.1016/j.gene.2017.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 09/13/2017] [Accepted: 10/07/2017] [Indexed: 01/23/2023]
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13
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BMP2 expression in the endocardial lineage is required for AV endocardial cushion maturation and remodeling. Dev Biol 2017; 430:113-128. [PMID: 28790014 DOI: 10.1016/j.ydbio.2017.08.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 07/16/2017] [Accepted: 08/04/2017] [Indexed: 12/13/2022]
Abstract
Distal outgrowth, maturation and remodeling of the endocardial cushion mesenchyme in the atrioventricular (AV) canal are the essential morphogenetic events during four-chambered heart formation. Mesenchymalized AV endocardial cushions give rise to the AV valves and the membranous ventricular septum (VS). Failure of these processes results in several human congenital heart defects. Despite this clinical relevance, the mechanisms governing how mesenchymalized AV endocardial cushions mature and remodel into the membranous VS and AV valves have only begun to be elucidated. The role of BMP signaling in the myocardial and secondary heart forming lineage has been well studied; however, little is known about the role of BMP2 expression in the endocardial lineage. To fill this knowledge gap, we generated Bmp2 endocardial lineage-specific conditional knockouts (referred to as Bmp2 cKOEndo) by crossing conditionally-targeted Bmp2flox/flox mice with a Cre-driver line, Nfatc1Cre, wherein Cre-mediated recombination was restricted to the endocardial cells and their mesenchymal progeny. Bmp2 cKOEndo mouse embryos did not exhibit failure or delay in the initial AV endocardial cushion formation at embryonic day (ED) 9.5-11.5; however, significant reductions in AV cushion size were detected in Bmp2 cKOEndo mouse embryos when compared to control embryos at ED13.5 and ED16.5. Moreover, deletion of Bmp2 from the endocardial lineage consistently resulted in membranous ventricular septal defects (VSDs), and mitral valve deficiencies, as evidenced by the absence of stratification of mitral valves at birth. Muscular VSDs were not found in Bmp2 cKOEndo mouse hearts. To understand the underlying morphogenetic mechanisms leading to a decrease in cushion size, cell proliferation and cell death were examined for AV endocardial cushions. Phospho-histone H3 analyses for cell proliferation and TUNEL assays for apoptotic cell death did not reveal significant differences between control and Bmp2 cKOEndo in AV endocardial cushions. However, mRNA expression of the extracellular matrix components, versican, Has2, collagen 9a1, and periostin was significantly reduced in Bmp2 cKOEndo AV cushions. Expression of transcription factors implicated in the cardiac valvulogenesis, Snail2, Twist1 and Sox9, was also significantly reduced in Bmp2 cKOEndo AV cushions. These data provide evidence that BMP2 expression in the endocardial lineage is essential for the distal outgrowth, maturation and remodeling of AV endocardial cushions into the normal membranous VS and the stratified AV valves.
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Wu B, Wang Y, Xiao F, Butcher JT, Yutzey KE, Zhou B. Developmental Mechanisms of Aortic Valve Malformation and Disease. Annu Rev Physiol 2017; 79:21-41. [DOI: 10.1146/annurev-physiol-022516-034001] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Bingruo Wu
- Departments of Genetics, Pediatrics, and Medicine (Cardiology), Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461;
| | - Yidong Wang
- Departments of Genetics, Pediatrics, and Medicine (Cardiology), Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461;
| | - Feng Xiao
- Departments of Genetics, Pediatrics, and Medicine (Cardiology), Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461;
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029 China
| | - Jonathan T. Butcher
- Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853;
| | - Katherine E. Yutzey
- Division of Molecular Cardiovascular Biology, Cincinnati Children's Medical Center, Cincinnati, Ohio 45229;
| | - Bin Zhou
- Departments of Genetics, Pediatrics, and Medicine (Cardiology), Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461;
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029 China
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15
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Bolar N, Verstraeten A, Van Laer L, Loeys B. Molecular Insights into Bicuspid Aortic Valve Development and the associated aortopathy. AIMS MOLECULAR SCIENCE 2017. [DOI: 10.3934/molsci.2017.4.478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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16
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Freeze SL, Landis BJ, Ware SM, Helm BM. Bicuspid Aortic Valve: a Review with Recommendations for Genetic Counseling. J Genet Couns 2016; 25:1171-1178. [PMID: 27550231 DOI: 10.1007/s10897-016-0002-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 07/31/2016] [Indexed: 12/16/2022]
Abstract
Bicuspid aortic valve (BAV) is the most common congenital heart defect and falls in the spectrum of left-sided heart defects, also known as left ventricular outflow tract obstructive (LVOTO) defects. BAV is often identified in otherwise healthy, asymptomatic individuals, but it is associated with serious long term health risks including progressive aortic valve disease (stenosis or regurgitation) and thoracic aortic aneurysm and dissection. BAV and other LVOTO defects have high heritability. Although recommendations for cardiac screening of BAV in at-risk relatives exist, there are no standard guidelines for providing genetic counseling to patients and families with BAV. This review describes current knowledge of BAV and associated aortopathy and provides guidance to genetic counselors involved in the care of patients and families with these malformations. The heritability of BAV and recommendations for screening are highlighted. While this review focuses specifically on BAV, the principles are applicable to counseling needs for other LVOTO defects.
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Affiliation(s)
- Samantha L Freeze
- Department of Pediatrics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Benjamin J Landis
- Department of Pediatrics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Medical & Molecular Genetics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, 975 West Walnut Street, IB-130, Indianapolis, IN, 46202, USA
| | - Stephanie M Ware
- Department of Pediatrics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Medical & Molecular Genetics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, 975 West Walnut Street, IB-130, Indianapolis, IN, 46202, USA
| | - Benjamin M Helm
- Department of Medical & Molecular Genetics, Riley Hospital for Children at IU Health, Indiana University School of Medicine, 975 West Walnut Street, IB-130, Indianapolis, IN, 46202, USA.
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17
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Haack T, Abdelilah-Seyfried S. The force within: endocardial development, mechanotransduction and signalling during cardiac morphogenesis. Development 2016; 143:373-86. [PMID: 26839341 DOI: 10.1242/dev.131425] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Endocardial cells are cardiac endothelial cells that line the interior of the heart tube. Historically, their contribution to cardiac development has mainly been considered from a morphological perspective. However, recent studies have begun to define novel instructive roles of the endocardium, as a sensor and signal transducer of biophysical forces induced by blood flow, and as an angiocrine signalling centre that is involved in myocardial cellular morphogenesis, regeneration and reprogramming. In this Review, we discuss how the endocardium develops, how endocardial-myocardial interactions influence the developing embryonic heart, and how the dysregulation of blood flow-responsive endocardial signalling can result in pathophysiological changes.
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Affiliation(s)
- Timm Haack
- Institute of Molecular Biology, Hannover Medical School, Carl-Neuberg Straße 1, Hannover D-30625, Germany
| | - Salim Abdelilah-Seyfried
- Institute of Molecular Biology, Hannover Medical School, Carl-Neuberg Straße 1, Hannover D-30625, Germany Institute of Biochemistry and Biology, Potsdam University, Karl-Liebknecht-Straße 24-25, Potsdam D-14476, Germany
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18
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Gould RA, Yalcin HC, MacKay JL, Sauls K, Norris R, Kumar S, Butcher JT. Cyclic Mechanical Loading Is Essential for Rac1-Mediated Elongation and Remodeling of the Embryonic Mitral Valve. Curr Biol 2015; 26:27-37. [PMID: 26725196 DOI: 10.1016/j.cub.2015.11.033] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 10/02/2015] [Accepted: 11/16/2015] [Indexed: 10/22/2022]
Abstract
During valvulogenesis, globular endocardial cushions elongate and remodel into highly organized thin fibrous leaflets. Proper regulation of this dynamic process is essential to maintain unidirectional blood flow as the embryonic heart matures. In this study, we tested how mechanosensitive small GTPases, RhoA and Rac1, coordinate atrioventricular valve (AV) differentiation and morphogenesis. RhoA activity and its regulated GTPase-activating protein FilGAP are elevated during early cushion formation but decreased considerably during valve remodeling. In contrast, Rac1 activity was nearly absent in the early cushions but increased substantially as the valve matured. Using gain- and loss-of-function assays, we determined that the RhoA pathway was essential for the contractile myofibroblastic phenotype present in early cushion formation but was surprisingly insufficient to drive matrix compaction during valve maturation. The Rac1 pathway was necessary to induce matrix compaction in vitro through increased cell adhesion, elongation, and stress fiber alignment. Facilitating this process, we found that acute cyclic stretch was a potent activator of RhoA and subsequently downregulated Rac1 activity via FilGAP. On the other hand, chronic cyclic stretch reduced active RhoA and downstream FilGAP, which enabled Rac1 activation. Finally, we used partial atrial ligation experiments to confirm in vivo that altered cyclic mechanical loading augmented or restricted cushion elongation and thinning, directly through potentiation of active Rac1 and active RhoA, respectively. Together, these results demonstrate that cyclic mechanical signaling coordinates the RhoA to Rac1 signaling transition essential for proper embryonic mitral valve remodeling.
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Affiliation(s)
- Russell A Gould
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Huseyin C Yalcin
- Qatar Cardiovascular Research Center (QCRC), Sidra Medical and Research Center, Doha, Qatar; Department of Mechanical Engineering, Dogus University, Istanbul 34722, Turkey
| | - Joanna L MacKay
- Department of Bioengineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Kimberly Sauls
- Department of Regenerative Medicine and Cell Biology, School of Medicine, Cardiovascular Developmental Biology Center, Children's Research Institute, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA
| | - Russell Norris
- Department of Regenerative Medicine and Cell Biology, School of Medicine, Cardiovascular Developmental Biology Center, Children's Research Institute, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, USA
| | - Sanjay Kumar
- Department of Bioengineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jonathan T Butcher
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
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19
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Deng X, Pan H, Wang J, Wang B, Cheng Z, Cheng L, Zhao L, Li H, Ma X. Functional Analysis of Two Novel Mutations in TWIST1 Protein Motifs Found in Ventricular Septal Defect Patients. Pediatr Cardiol 2015; 36:1602-9. [PMID: 25981568 DOI: 10.1007/s00246-015-1202-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/07/2015] [Indexed: 10/23/2022]
Abstract
The aim of this study was to investigate the possible genetic effect of sequence variations in TWIST1 on the pathogenesis of ventricular septal defect in humans. We examined the coding region of TWIST1 in a cohort of 196 Chinese people with non-syndromic ventricular septal defect patients and 200 healthy individuals as the controls. We identified two novel potential disease-associated mutations, NM_000474.3:c.247G>A (G83S) and NM_000474.3:c.283A>G (S95G). Both of them were identified for the first time and were not observed in the 200 controls without congenital heart disease. Using a dual-luciferase reporter assay, we showed that both of the mutations significantly down-regulated the repressive effect of TWIST1 on the E-cadherin promoter. Furthermore, a mammalian two-hybrid assay showed that both of the mutations significantly affected the interaction between TWIST1 and KAT2B. New mutations in the transcription factor TWIST1 that affect protein function were identified in 1.0 % (2/196) of Chinese patients with ventricular septal defect. Our data show, for the first time, that TWIST1 has a potential causative effect on the development of ventricular septal defect.
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Affiliation(s)
- Xiaopeng Deng
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, China
| | - Hong Pan
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Jing Wang
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Binbin Wang
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Zhi Cheng
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Longfei Cheng
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Lixi Zhao
- Graduate School, Peking Union Medical College, Beijing, 100080, China.,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China
| | - Hui Li
- Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No.36, Sanhao Street, Heping District, Shenyang, 110004, China.
| | - Xu Ma
- Graduate School, Peking Union Medical College, Beijing, 100080, China. .,Center for Genetics, National Research Institute for Family Planning, 12 Dahuisi Road, Haidian, Beijing, 100081, China. .,World Health Organization Collaborating Centre for Research in Human Reproduction, Beijing, 100081, China.
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20
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Garside VC, Cullum R, Alder O, Lu DY, Vander Werff R, Bilenky M, Zhao Y, Jones SJM, Marra MA, Underhill TM, Hoodless PA. SOX9 modulates the expression of key transcription factors required for heart valve development. Development 2015; 142:4340-50. [PMID: 26525672 DOI: 10.1242/dev.125252] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 10/28/2015] [Indexed: 01/10/2023]
Abstract
Heart valve formation initiates when endothelial cells of the heart transform into mesenchyme and populate the cardiac cushions. The transcription factor SOX9 is highly expressed in the cardiac cushion mesenchyme, and is essential for heart valve development. Loss of Sox9 in mouse cardiac cushion mesenchyme alters cell proliferation, embryonic survival, and valve formation. Despite this important role, little is known about how SOX9 regulates heart valve formation or its transcriptional targets. Therefore, we mapped putative SOX9 binding sites by ChIP-Seq in E12.5 heart valves, a stage at which the valve mesenchyme is actively proliferating and initiating differentiation. Embryonic heart valves have been shown to express a high number of genes that are associated with chondrogenesis, including several extracellular matrix proteins and transcription factors that regulate chondrogenesis. Therefore, we compared regions of putative SOX9 DNA binding between E12.5 heart valves and E12.5 limb buds. We identified context-dependent and context-independent SOX9-interacting regions throughout the genome. Analysis of context-independent SOX9 binding suggests an extensive role for SOX9 across tissues in regulating proliferation-associated genes including key components of the AP-1 complex. Integrative analysis of tissue-specific SOX9-interacting regions and gene expression profiles on Sox9-deficient heart valves demonstrated that SOX9 controls the expression of several transcription factors with previously identified roles in heart valve development, including Twist1, Sox4, Mecom and Pitx2. Together, our data identify SOX9-coordinated transcriptional hierarchies that control cell proliferation and differentiation during valve formation.
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Affiliation(s)
- Victoria C Garside
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada V5Z 1L3 Program in Cell and Developmental Biology, University of British Columbia, Vancouver, Canada V6T 1Z4
| | - Rebecca Cullum
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada V5Z 1L3
| | - Olivia Alder
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada V5Z 1L3
| | - Daphne Y Lu
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada V5Z 1L3
| | - Ryan Vander Werff
- Biomedical Research Centre, University of British Columbia, Vancouver, Canada V6T 1Z4
| | - Mikhail Bilenky
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, Canada V5Z 1L3
| | - Yongjun Zhao
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, Canada V5Z 1L3
| | - Steven J M Jones
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, Canada V5Z 1L3 Department of Medical Genetics, University of British Columbia, Vancouver, Canada V6T 1Z4 Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, Canada V5A 1S6
| | - Marco A Marra
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, Vancouver, Canada V5Z 1L3 Department of Medical Genetics, University of British Columbia, Vancouver, Canada V6T 1Z4
| | - T Michael Underhill
- Program in Cell and Developmental Biology, University of British Columbia, Vancouver, Canada V6T 1Z4 Biomedical Research Centre, University of British Columbia, Vancouver, Canada V6T 1Z4 Department of Medical Genetics, University of British Columbia, Vancouver, Canada V6T 1Z4
| | - Pamela A Hoodless
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada V5Z 1L3 Program in Cell and Developmental Biology, University of British Columbia, Vancouver, Canada V6T 1Z4 Department of Medical Genetics, University of British Columbia, Vancouver, Canada V6T 1Z4
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21
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BMPER Promotes Epithelial-Mesenchymal Transition in the Developing Cardiac Cushions. PLoS One 2015; 10:e0139209. [PMID: 26418455 PMCID: PMC4587915 DOI: 10.1371/journal.pone.0139209] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/10/2015] [Indexed: 01/25/2023] Open
Abstract
Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP) signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator) display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT) and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects.
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22
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Bowen CJ, Zhou J, Sung DC, Butcher JT. Cadherin-11 coordinates cellular migration and extracellular matrix remodeling during aortic valve maturation. Dev Biol 2015; 407:145-57. [PMID: 26188246 DOI: 10.1016/j.ydbio.2015.07.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 06/15/2015] [Accepted: 07/13/2015] [Indexed: 12/30/2022]
Abstract
Proper remodeling of the endocardial cushions into thin fibrous valves is essential for gestational progression and long-term function. This process involves dynamic interactions between resident cells and their local environment, much of which is not understood. In this study, we show that deficiency of the cell-cell adhesion protein cadherin-11 (Cad-11) results in significant embryonic and perinatal lethality primarily due to valve related cardiac dysfunction. While endocardial to mesenchymal transformation is not abrogated, mesenchymal cells do not homogeneously cellularize the cushions. These cushions remain thickened with disorganized ECM, resulting in pronounced aortic valve insufficiency. Mice that survive to adulthood maintain thickened and stenotic semilunar valves, but interestingly do not develop calcification. Cad-11 (-/-) aortic valve leaflets contained reduced Sox9 activity, β1 integrin expression, and RhoA-GTP activity, suggesting that remodeling defects are due to improper migration and/or cellular contraction. Cad-11 deletion or siRNA knockdown reduced migration, eliminated collective migration, and impaired 3D matrix compaction by aortic valve interstitial cells (VIC). Cad-11 depleted cells in culture contained few filopodia, stress fibers, or contact inhibited locomotion. Transfection of Cad-11 depleted cells with constitutively active RhoA restored cell phenotypes. Together, these results identify cadherin-11 mediated adhesive signaling for proper remodeling of the embryonic semilunar valves.
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Affiliation(s)
- Caitlin J Bowen
- Department of Biomedical Engineering, Cornell University, United States
| | - Jingjing Zhou
- Department of Biomedical Engineering, Cornell University, United States
| | - Derek C Sung
- Department of Biomedical Engineering, Cornell University, United States
| | - Jonathan T Butcher
- Department of Biomedical Engineering, Cornell University, United States.
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23
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Abstract
Dilation of the wall of the thoracic aorta can be found in patients with a tricuspid (TAV) as well as a bicuspid aortic valve (BAV) with and without a syndromic component. BAV is the most common congenital cardiovascular malformation, with a population prevalence of 0.5–2 %. The clinical course is often characterised by aneurysm formation and in some cases dissection. The non-dilated aortic wall is less well differentiated in all BAV as compared with TAV, thereby conferring inherent developmental susceptibility. Furthermore, a turbulent flow, caused by the inappropriate opening of the bicuspid valve, could accelerate the degenerative process in the aortic wall. However, not all patients with bicuspidy develop clinical complications during their life. We postulate that the increased vulnerability for aortic complications in a subset of patients with BAV is caused by a defect in the early development of the aorta and aortic valve. This review discusses histological and molecular genetic aspects of the normal and abnormal development of the aortic wall and semilunar valves. Aortopathy associated with BAV could be the result of a shared developmental defect during embryogenesis.
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24
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Clowes C, Boylan MGS, Ridge LA, Barnes E, Wright JA, Hentges KE. The functional diversity of essential genes required for mammalian cardiac development. Genesis 2014; 52:713-37. [PMID: 24866031 PMCID: PMC4141749 DOI: 10.1002/dvg.22794] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/04/2023]
Abstract
Genes required for an organism to develop to maturity (for which no other gene can compensate) are considered essential. The continuing functional annotation of the mouse genome has enabled the identification of many essential genes required for specific developmental processes including cardiac development. Patterns are now emerging regarding the functional nature of genes required at specific points throughout gestation. Essential genes required for development beyond cardiac progenitor cell migration and induction include a small and functionally homogenous group encoding transcription factors, ligands and receptors. Actions of core cardiogenic transcription factors from the Gata, Nkx, Mef, Hand, and Tbx families trigger a marked expansion in the functional diversity of essential genes from midgestation onwards. As the embryo grows in size and complexity, genes required to maintain a functional heartbeat and to provide muscular strength and regulate blood flow are well represented. These essential genes regulate further specialization and polarization of cell types along with proliferative, migratory, adhesive, contractile, and structural processes. The identification of patterns regarding the functional nature of essential genes across numerous developmental systems may aid prediction of further essential genes and those important to development and/or progression of disease. genesis 52:713–737, 2014.
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Affiliation(s)
- Christopher Clowes
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
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25
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Wirrig EE, Yutzey KE. Conserved transcriptional regulatory mechanisms in aortic valve development and disease. Arterioscler Thromb Vasc Biol 2014; 34:737-41. [PMID: 24665126 DOI: 10.1161/atvbaha.113.302071] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
There is increasing evidence for activation of developmental transcriptional regulatory pathways in heart valve disease. Here, we review molecular regulatory mechanisms involved in heart valve progenitor development, leaflet morphogenesis, and extracellular matrix organization that also are active in diseased aortic valves. These include regulators of endothelial-to-mesenchymal transitions, such as the Notch pathway effector RBPJ, and the valve progenitor markers Twist1, Msx1/2, and Sox9. Little is known of the potential reparative or pathological functions of these developmental mechanisms in adult aortic valves, but it is tempting to speculate that valve progenitor cells could contribute to repair in the context of disease. Likewise, loss of either RBPJ or Sox9 leads to aortic valve calcification in mice, supporting a potential therapeutic role in prevention of disease. During aortic valve calcification, transcriptional regulators of osteogenic development are activated in addition to valve progenitor regulatory programs. Specifically, the transcription factor Runx2 and its downstream target genes are induced in calcified valves. Runx2 and osteogenic genes also are induced with vascular calcification, but activation of valve progenitor markers and the cellular context of expression are likely to be different for valve and vascular calcification. Additional research is necessary to determine whether developmental mechanisms contribute to valve repair or whether these pathways can be harnessed for new treatments of heart valve disease.
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Affiliation(s)
- Elaine E Wirrig
- From The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
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26
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Chester AH, El-Hamamsy I, Butcher JT, Latif N, Bertazzo S, Yacoub MH. The living aortic valve: From molecules to function. Glob Cardiol Sci Pract 2014; 2014:52-77. [PMID: 25054122 PMCID: PMC4104380 DOI: 10.5339/gcsp.2014.11] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 04/28/2014] [Indexed: 12/12/2022] Open
Abstract
The aortic valve lies in a unique hemodynamic environment, one characterized by a range of stresses (shear stress, bending forces, loading forces and strain) that vary in intensity and direction throughout the cardiac cycle. Yet, despite its changing environment, the aortic valve opens and closes over 100,000 times a day and, in the majority of human beings, will function normally over a lifespan of 70–90 years. Until relatively recently heart valves were considered passive structures that play no active role in the functioning of a valve, or in the maintenance of its integrity and durability. However, through clinical experience and basic research the aortic valve can now be characterized as a living, dynamic organ with the capacity to adapt to its complex mechanical and biomechanical environment through active and passive communication between its constituent parts. The clinical relevance of a living valve substitute in patients requiring aortic valve replacement has been confirmed. This highlights the importance of using tissue engineering to develop heart valve substitutes containing living cells which have the ability to assume the complex functioning of the native valve.
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27
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Cai X, Zhang W, Hu J, Zhang L, Sultana N, Wu B, Cai W, Zhou B, Cai CL. Tbx20 acts upstream of Wnt signaling to regulate endocardial cushion formation and valve remodeling during mouse cardiogenesis. Development 2013; 140:3176-87. [PMID: 23824573 DOI: 10.1242/dev.092502] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cardiac valves are essential to direct forward blood flow through the cardiac chambers efficiently. Congenital valvular defects are prevalent among newborns and can cause an immediate threat to survival as well as long-term morbidity. Valve leaflet formation is a rigorously programmed process consisting of endocardial epithelial-mesenchymal transformation (EMT), mesenchymal cell proliferation, valve elongation and remodeling. Currently, little is known about the coordination of the diverse signals that regulate endocardial cushion development and valve elongation. Here, we report that the T-box transcription factor Tbx20 is expressed in the developing endocardial cushions and valves throughout heart development. Ablation of Tbx20 in endocardial cells causes severe valve elongation defects and impaired cardiac function in mice. Our study reveals that endocardial Tbx20 is crucial for valve endocardial cell proliferation and extracellular matrix development, but is not required for initiation of EMT. Elimination of Tbx20 also causes aberrant Wnt/β-catenin signaling in the endocardial cushions. In addition, Tbx20 regulates Lef1, a key transcriptional mediator for Wnt/β-catenin signaling, in this developmental process. Our study suggests a model in which Tbx20 regulates the Wnt pathway to direct endocardial cushion maturation and valve elongation, and provides new insights into the etiology of valve defects in humans.
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Affiliation(s)
- Xiaoqiang Cai
- Department of Developmental and Regenerative Biology, The Mindich Child Health and Development Institute, and The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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28
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Insufficient versican cleavage and Smad2 phosphorylation results in bicuspid aortic and pulmonary valves. J Mol Cell Cardiol 2013; 60:50-9. [PMID: 23531444 DOI: 10.1016/j.yjmcc.2013.03.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/10/2013] [Accepted: 03/11/2013] [Indexed: 12/29/2022]
Abstract
Bicuspid or bifoliate aortic valve (BAV) results in two rather than three cusps and occurs in 1-2% of the population placing them at higher risk of developing progressive aortic valve disease. Only NOTCH-1 has been linked to human BAV, and genetically modified mouse models of BAV are limited by low penetrance and additional malformations. Here we report that in the Adamts5(-/-) valves, collagen I, collagen III, and elastin were disrupted in the malformed hinge region that anchors the mature semilunar cusps and where the ADAMTS5 proteoglycan substrate versican, accumulates. ADAMTS5 deficient prevalvular mesenchyme also exhibited a reduction of α-smooth muscle actin and filamin A suggesting versican cleavage may be involved in TGFβ signaling. Subsequent evaluation showed a significant decrease of pSmad2 in regions of prevalvular mesenchyme in Adamts5(-/-) valves. To test the hypothesis that ADAMTS5 versican cleavage is required, in part, to elicit Smad2 phosphorylation we further reduced Smad2 in Adamts5(-/-) mice through intergenetic cross. The Adamts5(-/-);Smad2(+/-) mice had highly penetrant BAV and bicuspid pulmonary valve (BPV) malformations as well as increased cusp and hinge size compared to the Adamts5(-/-) and control littermates. These studies demonstrate that semilunar cusp malformations (BAV and BPV) can arise from a failure to remodel the proteoglycan-rich provisional ECM. Specifically, faulty versican clearance due to ADAMTS5 deficiency blocks the initiation of pSmad2 signaling, which is required for excavation of endocardial cushions during aortic and pulmonary valve development. Further studies using the Adamts5(-/-); Smad2(+/-) mice with highly penetrant and isolated BAV, may lead to new pharmacological treatments for valve disease.
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Mead TJ, Wang Q, Bhattaram P, Dy P, Afelik S, Jensen J, Lefebvre V. A far-upstream (-70 kb) enhancer mediates Sox9 auto-regulation in somatic tissues during development and adult regeneration. Nucleic Acids Res 2013; 41:4459-69. [PMID: 23449223 PMCID: PMC3632127 DOI: 10.1093/nar/gkt140] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
SOX9 encodes a transcription factor that presides over the specification and differentiation of numerous progenitor and differentiated cell types, and although SOX9 haploinsufficiency and overexpression cause severe diseases in humans, including campomelic dysplasia, sex reversal and cancer, the mechanisms underlying SOX9 transcription remain largely unsolved. We identify here an evolutionarily conserved enhancer located 70-kb upstream of mouse Sox9 and call it SOM because it specifically activates a Sox9 promoter reporter in most Sox9-expressing somatic tissues in transgenic mice. Moreover, SOM-null fetuses and pups reduce Sox9 expression by 18–37% in the pancreas, lung, kidney, salivary gland, gut and liver. Weanlings exhibit half-size pancreatic islets and underproduce insulin and glucagon, and adults slowly recover from acute pancreatitis due to a 2-fold impairment in Sox9 upregulation. Molecular and genetic experiments reveal that Sox9 protein dimers bind to multiple recognition sites in the SOM sequence and are thereby both necessary and sufficient for enhancer activity. These findings thus uncover that Sox9 directly enhances its functions in somatic tissue development and adult regeneration through SOM-mediated positive auto-regulation. They provide thereby novel insights on molecular mechanisms controlling developmental and disease processes and suggest new strategies to improve disease treatments.
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Affiliation(s)
- Timothy J Mead
- Department of Cellular and Molecular Medicine, and Orthopaedic and Rheumatologic Research Center, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
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30
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Rosenquist TH. Folate, Homocysteine and the Cardiac Neural Crest. Dev Dyn 2013; 242:201-18. [DOI: 10.1002/dvdy.23922] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/21/2012] [Accepted: 12/21/2012] [Indexed: 12/21/2022] Open
Affiliation(s)
- Thomas H. Rosenquist
- Department of Genetics; Cell Biology and Anatomy; University of Nebraska Medical Center; Omaha; Nebraska
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Li C, Xu S, Gotlieb AI. The progression of calcific aortic valve disease through injury, cell dysfunction, and disruptive biologic and physical force feedback loops. Cardiovasc Pathol 2013; 22:1-8. [DOI: 10.1016/j.carpath.2012.06.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 06/01/2012] [Accepted: 06/04/2012] [Indexed: 10/28/2022] Open
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Abdul-Sater Z, Yehya A, Beresian J, Salem E, Kamar A, Baydoun S, Shibbani K, Soubra A, Bitar F, Nemer G. Two heterozygous mutations in NFATC1 in a patient with Tricuspid Atresia. PLoS One 2012; 7:e49532. [PMID: 23226213 PMCID: PMC3511479 DOI: 10.1371/journal.pone.0049532] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 10/10/2012] [Indexed: 11/19/2022] Open
Abstract
Tricuspid Atresia (TA) is a rare form of congenital heart disease (CHD) with usually poor prognosis in humans. It presents as a complete absence of the right atrio-ventricular connection secured normally by the tricuspid valve. Defects in the tricuspid valve are so far not associated with any genetic locus, although mutations in numerous genes were linked to multiple forms of congenital heart disease. In the last decade, Knock-out mice have offered models for cardiologists and geneticists to study the causes of congenital disease. One such model was the Nfatc1(-/-) mice embryos which die at mid-gestation stage due to a complete absence of the valves. NFATC1 belongs to the Rel family of transcription factors members of which were shown to be implicated in gene activation, cell differentiation, and organogenesis. We have previously shown that a tandem repeat in the intronic region of NFATC1 is associated with ventricular septal defects. In this report, we unravel for the first time a potential link between a mutation in NFATC1 and TA. Two heterozygous missense mutations were found in the NFATC1 gene in one indexed-case out of 19 patients with TA. The two amino-acids changes were not found neither in other patients with CHDs, nor in the control healthy population. Moreover, we showed that these mutations alter dramatically the normal function of the protein at the cellular localization, DNA binding and transcriptional levels suggesting they are disease-causing.
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Affiliation(s)
- Zahi Abdul-Sater
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Amin Yehya
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Jean Beresian
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Elie Salem
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Amina Kamar
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Serine Baydoun
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Kamel Shibbani
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Ayman Soubra
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Fadi Bitar
- Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon
| | - Georges Nemer
- Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
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Abstract
The heart as a functional organ first appeared in bilaterians as a single peristaltic pump and evolved through arthropods, fish, amphibians, and finally mammals into a four-chambered engine controlling blood-flow within the body. The acquisition of cardiac complexity in the evolving heart was a product of gene duplication events and the co-option of novel signaling pathways to an ancestral cardiac-specific gene network. T-box factors belong to an evolutionary conserved family of transcriptional regulators with diverse roles in development. Their regulatory functions are integral in the initiation and potentiation of heart development, and mutations in these genes are associated with congenital heart defects. In this review we will discuss the evolutionary conserved cardiac regulatory functions of this family as well as their implication in disease in an aim to facilitate future gene-targeted and regenerative therapeutic remedies.
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Affiliation(s)
- Fadi Hariri
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, C.P. 6128, Succursale, Centre-ville Montréal, Quebec, H3C3J7, Canada
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Padang R, Bagnall RD, Semsarian C. Genetic Basis of Familial Valvular Heart Disease. ACTA ACUST UNITED AC 2012; 5:569-80. [DOI: 10.1161/circgenetics.112.962894] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Ratnasari Padang
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia (R.P., R.D.B., C.S.); Sydney Medical School, University of Sydney, Sydney, Australia (R.P., C.S.); and Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia (R.P., C.S.)
| | - Richard D. Bagnall
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia (R.P., R.D.B., C.S.); Sydney Medical School, University of Sydney, Sydney, Australia (R.P., C.S.); and Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia (R.P., C.S.)
| | - Christopher Semsarian
- From the Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia (R.P., R.D.B., C.S.); Sydney Medical School, University of Sydney, Sydney, Australia (R.P., C.S.); and Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia (R.P., C.S.)
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Xu S, Gotlieb AI. Wnt3a/β-catenin increases proliferation in heart valve interstitial cells. Cardiovasc Pathol 2012; 22:156-66. [PMID: 22889676 DOI: 10.1016/j.carpath.2012.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 06/21/2012] [Accepted: 06/22/2012] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Valve interstitial cells (VICs), the most prevalent cells in the heart valve, mediate normal valve function and repair in valve injury and disease. The Wnt3a/β-catenin pathway, important for proliferation and endothelial-to-mesenchymal transition in endocardial cushion formation in valve development, is up-regulated in adult valves with calcific aortic stenosis. Therefore, we tested the hypothesis that Wnt3a/β-catenin signaling regulates proliferation in adult VICs. METHODS Porcine VICs were treated with 150 ng/ml of exogenous Wnt3a. To measure proliferation, cells were counted on day 4 posttreatment and stained for bromodeoxyuridine (BrdU) at 24 h posttreatment. β-Catenin small interfering RNA (siRNA) was used to knock down β-catenin expression. Apoptosis was measured with terminal deoxynucleotidyl transferase dUTP nick end labeling assay. To assess changes in β-catenin, cells were stained for β-catenin at days 1, 3, 6, and 9 posttreatment. Western blot for β-catenin was performed on whole cell, cytoplasmic, and nuclear extracts at day 4 posttreatment. To measure β-catenin-mediated transcription, TOPFLASH/FOPFLASH reporter assay was performed at 24 h posttreatment. RESULTS Wnt3a produced a significant increase in cell number at day 4 posttreatment and in the percentage of BrdU-positive nuclei at 24 h posttreatment. The increase in proliferation was abolished by β-catenin siRNA. Apoptosis was minimal in all conditions. Wnt3a produced progressively greater β-catenin staining as treatment length increased from 1 to 9 days. Wnt3a produced a significant increase in β-catenin protein in both whole cell and nuclear lysates after 4 days of treatment. Wnt3a significantly increased TOPFLASH/FOPFLASH reporter activity after 24 h of treatment. CONCLUSION Wnt3a/β-catenin signaling pathway is an important regulator of proliferation in adult VICs.
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Affiliation(s)
- Songyi Xu
- Department of Pathology, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada M5S 1A8
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Abstract
Bicuspid aortic valve (BAV) is the most common congenital heart defect, affecting 1-2% of the population. It is generally diagnosed late in adulthood when deterioration of the abnormal leaflet becomes clinically evident. BAV patients have an increased risk of developing serious complications, including stenosis, regurgitation, endocarditis, dilation of the aorta, aortic dissection, and aneurysm. BAV is a heritable trait, but the genetic basis underlying this cardiac malformation remains poorly understood. In the last decade, thanks to studies in animal models as well as genetic and biochemical approaches, a large number of genes that play important roles in heart development have been identified. These discoveries provided valuable insight into cardiac morphogenesis and uncovered congenital-heart-disease-causing genes. This paper will summarize the current knowledge of valve morphogenesis as well as our current understanding of the genetic pathways involved in BAV formation. The impact of these advances on human health including diagnosis of BAV and prevention of cardiovascular complications in individuals with BAV or with a family history of BAV is also discussed.
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de Vlaming A, Sauls K, Hajdu Z, Visconti RP, Mehesz AN, Levine RA, Slaugenhaupt SA, Hagège A, Chester AH, Markwald RR, Norris RA. Atrioventricular valve development: new perspectives on an old theme. Differentiation 2012; 84:103-16. [PMID: 22579502 DOI: 10.1016/j.diff.2012.04.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/26/2012] [Accepted: 04/01/2012] [Indexed: 11/19/2022]
Abstract
Atrioventricular valve development commences with an EMT event whereby endocardial cells transform into mesenchyme. The molecular events that induce this phenotypic change are well understood and include many growth factors, signaling components, and transcription factors. Besides their clear importance in valve development, the role of these transformed mesenchyme and the function they serve in the developing prevalve leaflets is less understood. Indeed, we know that these cells migrate, but how and why do they migrate? We also know that they undergo a transition to a mature, committed cell, largely defined as an interstitial fibroblast due to their ability to secrete various matrix components including collagen type I. However, we have yet to uncover mechanisms by which the matrix is synthesized, how it is secreted, and how it is organized. As valve disease is largely characterized by altered cell number, cell activation, and matrix disorganization, answering questions of how the valves are built will likely provide us with information of real clinical relevance. Although expression profiling and descriptive or correlative analyses are insightful, to advance the field, we must now move past the simplicity of these assays and ask fundamental, mechanistic based questions aimed at understanding how valves are "built". Herein we review current understandings of atrioventricular valve development and present what is known and what isn't known. In most cases, basic, biological questions and hypotheses that were presented decades ago on valve development still are yet to be answered but likely hold keys to uncovering new discoveries with relevance to both embryonic development and the developmental basis of adult heart valve diseases. Thus, the goal of this review is to remind us of these questions and provide new perspectives on an old theme of valve development.
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Affiliation(s)
- Annemarieke de Vlaming
- Department of Regenerative Medicine and Cell Biology, School of Medicine, Cardiovascular Developmental Biology Center, Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425, USA
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38
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Abstract
Heart valves are dynamic structures that open and close during the cardiac cycle to maintain unidirectional blood flow throughout life. Insufficient valve function, commonly due to congenital malformations leads to disruptions in hemodynamics and eventual heart failure. Mature valve leaflets are composed of a heterogeneous population of interstitial cells and stratified extracellular matrix, surrounded by a layer of endothelial cells. This defined connective tissue "architecture" provides the valve with all the necessary biomechanical properties required to efficiently function while withstanding constant cyclic shear stress. Valvular endothelial cells (VECs) play essential roles in establishing the valve structures during embryonic development and are important for maintaining lifelong valve integrity and function. In contrast to a continuous endothelium over the surface of healthy valve leaflets, VEC disruption is commonly observed in malfunctioning valves and is associated with pathological processes that promote valve sclerosis and calcification. Increasing our understanding of the roles of VECs in development and disease has lead to promising advances in the development of endothelial cell-based therapies for treating valve disease.
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Doetschman T, Barnett JV, Runyan RB, Camenisch TD, Heimark RL, Granzier HL, Conway SJ, Azhar M. Transforming growth factor beta signaling in adult cardiovascular diseases and repair. Cell Tissue Res 2011; 347:203-23. [PMID: 21953136 DOI: 10.1007/s00441-011-1241-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 09/02/2011] [Indexed: 01/15/2023]
Abstract
The majority of children with congenital heart disease now live into adulthood due to the remarkable surgical and medical advances that have taken place over the past half century. Because of this, adults now represent the largest age group with adult cardiovascular diseases. It includes patients with heart diseases that were not detected or not treated during childhood, those whose defects were surgically corrected but now need revision due to maladaptive responses to the procedure, those with exercise problems and those with age-related degenerative diseases. Because adult cardiovascular diseases in this population are relatively new, they are not well understood. It is therefore necessary to understand the molecular and physiological pathways involved if we are to improve treatments. Since there is a developmental basis to adult cardiovascular disease, transforming growth factor beta (TGFβ) signaling pathways that are essential for proper cardiovascular development may also play critical roles in the homeostatic, repair and stress response processes involved in adult cardiovascular diseases. Consequently, we have chosen to summarize the current information on a subset of TGFβ ligand and receptor genes and related effector genes that, when dysregulated, are known to lead to cardiovascular diseases and adult cardiovascular deficiencies and/or pathologies. A better understanding of the TGFβ signaling network in cardiovascular disease and repair will impact genetic and physiologic investigations of cardiovascular diseases in elderly patients and lead to an improvement in clinical interventions.
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Gu H, Gong J, Qiu W, Cao H, Xu J, Chen S, Chen Y. Association of a Tandem Repeat Polymorphism in NFATc1 with Increased Risk of Perimembranous Ventricular Septal Defect in a Chinese Population. Biochem Genet 2011; 49:592-600. [DOI: 10.1007/s10528-011-9434-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 09/29/2010] [Indexed: 10/18/2022]
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Wirrig EE, Yutzey KE. Transcriptional regulation of heart valve development and disease. Cardiovasc Pathol 2010; 20:162-7. [PMID: 20705485 DOI: 10.1016/j.carpath.2010.06.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 06/28/2010] [Indexed: 10/19/2022] Open
Abstract
Aortic valve disease is estimated to affect 2% of the United States population. There is increasing evidence that aortic valve disease has a basis in development, as congenital valve malformations are prevalent in patients undergoing valve replacement surgery. In fact, a number of genetic mutations have been linked to valve malformations and disease. In the initial stages of aortic valve pathogenesis, the valvular interstitial cells become activated, undergo cell proliferation, and participate in extracellular matrix remodeling. Many of these cell properties are shared with mesenchymal progenitor cells of the normally developing valves and bones. Historically, valve calcification was thought to be a passive process reflecting end-stage disease. However, recent evidence describes the increased expression of transcription factors in diseased AoV that are common to valvulogenic and osteogenic processes. These studies lend support to the idea that a developmental gene program is reactivated in aortic valve disease and may contribute to the molecular mechanisms underlying valve calcification in disease.
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Affiliation(s)
- Elaine E Wirrig
- Division of Molecular Cardiovascular Biology, The Heart Institute, Cincinnati Children's Medical Center, Cincinnati, OH 45229, USA
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