151
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Opitz R, Antonica F, Costagliola S. New model systems to illuminate thyroid organogenesis. Part I: an update on the zebrafish toolbox. Eur Thyroid J 2013; 2:229-42. [PMID: 24783054 PMCID: PMC3923603 DOI: 10.1159/000357079] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 11/07/2013] [Indexed: 12/16/2022] Open
Abstract
Thyroid dysgenesis (TD) resulting from defects during embryonic thyroid development represents a major cause of congenital hypothyroidism. The pathogenetic mechanisms of TD in human newborns, however, are still poorly understood and disease-causing genetic variants have been identified in only a small percentage of TD cases. This limited understanding of the pathogenesis of TD is partly due to a lack of knowledge on how intrinsic factors and extrinsic signalling cues orchestrate the differentiation of thyroid follicular cells and the morphogenesis of thyroid tissue. Recently, embryonic stem cells and zebrafish embryos emerged as novel model systems that allow for innovative experimental approaches in order to decipher cellular and molecular mechanisms of thyroid development and to unravel pathogenic mechanisms of TD. Zebrafish embryos offer several salient properties for studies on thyroid organogenesis including rapid and external development, optical transparency, ease of breeding, relative short generation time and amenability for genome editing. In this review, we will highlight recent advances in the zebrafish toolkit to visualize cellular dynamics of organ development and discuss specific prospects of the zebrafish model for studies on vertebrate thyroid development and human congenital thyroid diseases.
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Affiliation(s)
- Robert Opitz
- Institute of Interdisciplinary Research in Molecular Human Biology, Université Libre de Bruxelles, Brussels, Belgium
| | - Francesco Antonica
- Institute of Interdisciplinary Research in Molecular Human Biology, Université Libre de Bruxelles, Brussels, Belgium
| | - Sabine Costagliola
- Institute of Interdisciplinary Research in Molecular Human Biology, Université Libre de Bruxelles, Brussels, Belgium
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152
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Grajevskaja V, Balciuniene J, Balciunas D. Chicken β-globin insulators fail to shield the nkx2.5 promoter from integration site effects in zebrafish. Mol Genet Genomics 2013; 288:717-25. [PMID: 24036575 PMCID: PMC4104600 DOI: 10.1007/s00438-013-0778-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 08/23/2013] [Indexed: 10/26/2022]
Abstract
Genetic lineage tracing and conditional mutagenesis are developmental genetics techniques reliant on precise tissue-specific expression of transgenes. In the mouse, high specificity is usually achieved by inserting the transgene into the locus of interest through homologous recombination in embryonic stem cells. In the zebrafish, DNA containing the transgenic construct is randomly integrated into the genome, usually through transposon-mediated transgenesis. Expression of such transgenes is affected by regulatory features surrounding the integration site from general accessibility of chromatin to tissue-specific enhancers. We tested if the 1.2 kb cHS4 insulators derived from the chicken β-globin locus can shield a transgene from chromosomal position effects in the zebrafish genome. As our test promoters, we used two different-length versions of the zebrafish nkx2.5. We found that flanking a transgenic construct by cHS4 insulation sequences leads to overall increase in the expression of nkx2.5:mRFP. However, we also observed a very high degree of variability of mRFP expression, indicating that cHS4 insulators fail to protect nkx2.5:mRFP from falling under the control of enhancers in the vicinity of integration site.
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Affiliation(s)
- Viktorija Grajevskaja
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
- Department of Zoology, Faculty of Natural Sciences, Vilnius University, Vilnius, Lithuania
| | | | - Darius Balciunas
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
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153
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Gu A, Ji G, Yan L, Zhou Y. The 8-oxoguanine DNA glycosylase 1 (ogg1) decreases the vulnerability of the developing brain to DNA damage. DNA Repair (Amst) 2013; 12:1094-104. [DOI: 10.1016/j.dnarep.2013.08.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/17/2013] [Accepted: 08/27/2013] [Indexed: 12/17/2022]
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154
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Poon KL, Brand T. The zebrafish model system in cardiovascular research: A tiny fish with mighty prospects. Glob Cardiol Sci Pract 2013; 2013:9-28. [PMID: 24688998 PMCID: PMC3963735 DOI: 10.5339/gcsp.2013.4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/29/2013] [Indexed: 12/26/2022] Open
Affiliation(s)
- Kar Lai Poon
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom
| | - Thomas Brand
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom
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155
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Heart field origin of great vessel precursors relies on nkx2.5-mediated vasculogenesis. Nat Cell Biol 2013; 15:1362-9. [PMID: 24161929 PMCID: PMC3864813 DOI: 10.1038/ncb2862] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 09/18/2013] [Indexed: 01/12/2023]
Abstract
The pharyngeal arch arteries (PAAs) are transient embryonic blood vessels that make indispensable contributions to the carotid arteries and great vessels of the heart, including the aorta and pulmonary artery1, 2. During embryogenesis, the PAAs appear in a craniocaudal sequence to connect pre-existing segments of the primitive circulation after de novo vasculogenic assembly from angioblast precursors3, 4. Despite the unique spatiotemporal characteristics of PAA development, the embryonic origins of PAA angioblasts and the genetic factors regulating their emergence remain unknown. Here, we identify the embryonic source of PAA endothelium as nkx2.5+ progenitors in lateral plate mesoderm long considered to adopt cell fates within the heart exclusively5, 6. Further, we report that PAA endothelial differentiation relies on Nkx2.5, a canonical cardiac transcription factor not previously implicated in blood vessel formation. Together, these studies reveal the heart field origin of PAA endothelium and attribute a novel vasculogenic function to the cardiac transcription factor nkx2.5 during great vessel precursor development.
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156
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Corallo D, Schiavinato A, Trapani V, Moro E, Argenton F, Bonaldo P. Emilin3 is required for notochord sheath integrity and interacts with Scube2 to regulate notochord-derived Hedgehog signals. Development 2013; 140:4594-601. [PMID: 24131633 DOI: 10.1242/dev.094078] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The notochord is a transient and essential structure that provides both mechanical and signaling cues to the developing vertebrate embryo. In teleosts, the notochord is composed of a core of large vacuolated cells and an outer layer of cells that secrete the notochord sheath. In this work, we have identified the extracellular matrix glycoprotein Emilin3 as a novel essential component of the zebrafish notochord sheath. The development of the notochord sheath is impaired in Emilin3 knockdown embryos. The patterning activity of the notochord is also affected by Emilin3, as revealed by the increase of Hedgehog (Hh) signaling in Emilin3-depleted embryos and the decreased Hh signaling in embryos overexpressing Emilin3 in the notochord. In vitro and in vivo experiments indicate that Emilin3 modulates the availability of Hh ligands by interacting with the permissive factor Scube2 in the notochord sheath. Overall, this study reveals a new role for an EMILIN protein and reinforces the concept that structure and function of the notochord are strictly linked.
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Affiliation(s)
- Diana Corallo
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
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157
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Incardona JP, Swarts TL, Edmunds RC, Linbo TL, Aquilina-Beck A, Sloan CA, Gardner LD, Block BA, Scholz NL. Exxon Valdez to Deepwater Horizon: comparable toxicity of both crude oils to fish early life stages. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 142-143:303-16. [PMID: 24080042 DOI: 10.1016/j.aquatox.2013.08.011] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/18/2013] [Accepted: 08/20/2013] [Indexed: 05/23/2023]
Abstract
The 2010 Deepwater Horizon disaster in the Gulf of Mexico was the largest oil spill in United States history. Crude oils are highly toxic to developing fish embryos, and many pelagic fish species were spawning in the northern Gulf in the months before containment of the damaged Mississippi Canyon 252 (MC252) wellhead (April-July). The largest prior U.S. spill was the 1989 grounding of the Exxon Valdez that released 11 million gallons of Alaska North Slope crude oil (ANSCO) into Prince William Sound. Numerous studies in the aftermath of the Exxon Valdez spill defined a conventional crude oil injury phenotype in fish early life stages, mediated primarily by toxicity to the developing heart. To determine whether this type of injury extends to fishes exposed to crude oil from the Deepwater Horizon - MC252 incident, we used zebrafish to compare the embryotoxicity of ANSCO alongside unweathered and weathered MC252 oil. We also developed a standardized protocol for generating dispersed oil water-accommodated fractions containing microdroplets of crude oil in the size range of those detected in subsurface plumes in the Gulf. We show here that MC252 oil and ANSCO cause similar cardiotoxicity and photo-induced toxicity in zebrafish embryos. Morphological defects and patterns of cytochrome P450 induction were largely indistinguishable and generally correlated with polycyclic aromatic compound (PAC) composition of each oil type. Analyses of embryos exposed during different developmental windows provided additional insight into mechanisms of crude oil cardiotoxicity. These findings indicate that the impacts of MC252 crude oil on fish embryos and larvae are consistent with the canonical ANSCO cardiac injury phenotype. For those marine fish species that spawned in the northern Gulf of Mexico during and after the Deepwater Horizon incident, the established literature can therefore inform the assessment of natural resource injury in the form of potential year-class losses.
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Affiliation(s)
- John P Incardona
- Environmental Conservation Division, Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard East, Seattle, WA 98112, United States.
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158
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Targoff KL, Colombo S, George V, Schell T, Kim SH, Solnica-Krezel L, Yelon D. Nkx genes are essential for maintenance of ventricular identity. Development 2013; 140:4203-13. [PMID: 24026123 DOI: 10.1242/dev.095562] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Establishment of specific characteristics of each embryonic cardiac chamber is crucial for development of a fully functional adult heart. Despite the importance of defining and maintaining unique features in ventricular and atrial cardiomyocytes, the regulatory mechanisms guiding these processes are poorly understood. Here, we show that the homeodomain transcription factors Nkx2.5 and Nkx2.7 are necessary to sustain ventricular chamber attributes through repression of atrial chamber identity. Mutation of nkx2.5 in zebrafish yields embryos with diminutive ventricular and bulbous atrial chambers. These chamber deformities emerge gradually during development, with a severe collapse in the number of ventricular cardiomyocytes and an accumulation of excess atrial cardiomyocytes as the heart matures. Removal of nkx2.7 function from nkx2.5 mutants exacerbates the loss of ventricular cells and the gain of atrial cells. Moreover, in these Nkx-deficient embryos, expression of vmhc, a ventricular gene, fades, whereas expression of amhc, an atrial gene, expands. Cell-labeling experiments suggest that ventricular cardiomyocytes can transform into atrial cardiomyocytes in the absence of Nkx gene function. Through suggestion of transdifferentiation from ventricular to atrial fate, our data reveal a pivotal role for Nkx genes in maintaining ventricular identity and highlight remarkable plasticity in differentiated myocardium. Thus, our results are relevant to the etiologies of fetal and neonatal cardiac pathology and could direct future innovations in cardiac regenerative medicine.
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Affiliation(s)
- Kimara L Targoff
- Developmental Genetics Program and Department of Cell Biology, Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
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159
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Sarmah S, Marrs JA. Complex cardiac defects after ethanol exposure during discrete cardiogenic events in zebrafish: prevention with folic acid. Dev Dyn 2013; 242:1184-201. [PMID: 23832875 DOI: 10.1002/dvdy.24015] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/13/2013] [Accepted: 07/01/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Fetal alcohol spectrum disorder (FASD) describes a range of birth defects including various congenital heart defects (CHDs). Mechanisms of FASD-associated CHDs are not understood. Whether alcohol interferes with a single critical event or with multiple events in heart formation is not known. RESULTS Our zebrafish embryo experiments showed that ethanol interrupts different cardiac regulatory networks and perturbs multiple steps of cardiogenesis (specification, myocardial migration, looping, chamber morphogenesis, and endocardial cushion formation). Ethanol exposure during gastrulation until cardiac specification or during myocardial midline migration did not produce severe or persistent heart development defects. However, exposure comprising gastrulation until myocardial precursor midline fusion or during heart patterning stages produced aberrant heart looping and defective endocardial cushions. Continuous exposure during entire cardiogenesis produced complex cardiac defects leading to severely defective myocardium, endocardium, and endocardial cushions. Supplementation of retinoic acid with ethanol partially rescued early heart developmental defects, but the endocardial cushions did not form correctly. In contrast, supplementation of folic acid rescued normal heart development, including the endocardial cushions. CONCLUSIONS Our results indicate that ethanol exposure interrupted divergent cardiac morphogenetic events causing heart defects. Folic acid supplementation was effective in preventing a wide spectrum of ethanol-induced heart developmental defects.
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Affiliation(s)
- Swapnalee Sarmah
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
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160
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Novikov N, Evans T. Tmem88a mediates GATA-dependent specification of cardiomyocyte progenitors by restricting WNT signaling. Development 2013; 140:3787-98. [PMID: 23903195 DOI: 10.1242/dev.093567] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Biphasic control of WNT signaling is essential during cardiogenesis, but how the pathway switches from promoting cardiac mesoderm to restricting cardiomyocyte progenitor fate is unknown. We identified genes expressed in lateral mesoderm that are dysregulated in zebrafish when both gata5 and gata6 are depleted, causing a block to cardiomyocyte specification. This screen identified tmem88a, which is expressed in the early cardiac progenitor field and was previously implicated in WNT modulation by overexpression studies. Depletion of tmem88a results in a profound cardiomyopathy, secondary to impaired cardiomyocyte specification. In tmem88a morphants, activation of the WNT pathway exacerbates the cardiomyocyte deficiency, whereas WNT inhibition rescues progenitor cells and cardiogenesis. We conclude that specification of cardiac fate downstream of gata5/6 involves activation of the tmem88a gene to constrain WNT signaling and expand the number of cardiac progenitors. Tmem88a is a novel component of the regulatory mechanism controlling the second phase of biphasic WNT activity essential for embryonic cardiogenesis.
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Affiliation(s)
- Natasha Novikov
- Department of Surgery, Weill Cornell Medical College, Cornell University, 1300 York Ave., LC-708, New York, NY, USA
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161
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8-Oxoguanine DNA glycosylase 1 (ogg1) maintains the function of cardiac progenitor cells during heart formation in zebrafish. Exp Cell Res 2013; 319:2954-63. [PMID: 23892003 DOI: 10.1016/j.yexcr.2013.07.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 11/27/2022]
Abstract
Genomic damage may devastate the potential of progenitor cells and consequently impair early organogenesis. We found that ogg1, a key enzyme initiating the base-excision repair, was enriched in the embryonic heart in zebrafish. So far, little is known about DNA repair in cardiogenesis. Here, we addressed the critical role of ogg1 in cardiogenesis for the first time. ogg1 mainly expressed in the anterior lateral plate mesoderm (ALPM), the primary heart tube, and subsequently the embryonic myocardium by in situ hybridisation. Loss of ogg1 resulted in severe cardiac morphogenesis and functional abnormalities, including the short heart length, arrhythmia, decreased cardiomyocytes and nkx2.5(+) cardiac progenitor cells. Moreover, the increased apoptosis and repressed proliferation of progenitor cells caused by ogg1 deficiency might contribute to the heart phenotype. The microarray analysis showed that the expression of genes involved in embryonic heart tube morphogenesis and heart structure were significantly changed due to the lack of ogg1. Among those, foxh1 is an important partner of ogg1 in the cardiac development in response to DNA damage. Our work demonstrates the requirement of ogg1 in cardiac progenitors and heart development in zebrafish. These findings may be helpful for understanding the aetiology of congenital cardiac deficits.
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162
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Robertson IB, Rifkin DB. Unchaining the beast; insights from structural and evolutionary studies on TGFβ secretion, sequestration, and activation. Cytokine Growth Factor Rev 2013; 24:355-72. [PMID: 23849989 DOI: 10.1016/j.cytogfr.2013.06.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 02/06/2023]
Abstract
TGFβ is secreted in a latent state and must be "activated" by molecules that facilitate its release from a latent complex and allow binding to high affinity cell surface receptors. Numerous molecules have been implicated as potential mediators of this activation process, but only a limited number of these activators have been demonstrated to play a role in TGFβ mobilisation in vivo. Here we review the process of TGFβ secretion and activation using evolutionary data, sequence conservation and structural information to examine the molecular mechanisms by which TGFβ is secreted, sequestered and released. This allows the separation of more ancient TGFβ activators from those factors that emerged more recently, and helps to define a potential hierarchy of activation mechanisms.
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Affiliation(s)
- Ian B Robertson
- Department of Cell Biology, New York University School of Medicine, 550 First Avenue, Cell Biology Floor 6 Room 650, Medical Science Building, New York, NY 10016, United States.
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163
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Bennett JS, Stroud DM, Becker JR, Roden DM. Proliferation of embryonic cardiomyocytes in zebrafish requires the sodium channel scn5Lab. Genesis 2013; 51:562-74. [PMID: 23650201 DOI: 10.1002/dvg.22400] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 03/24/2013] [Accepted: 04/29/2013] [Indexed: 12/30/2022]
Abstract
In mice, homozygous deletion of the cardiac sodium channel Scn5a results in defects in cardiac morphology and embryonic death before robust sodium current can be detected. In zebrafish, morpholino knockdown of cardiac sodium channel orthologs scn5Laa and scn5Lab perturbs specification of precardiac mesoderm and inhibits growth of the embryonic heart. It is not known which developmental processes are perturbed by sodium channel knockdown and whether reduced cell number is from impaired migration of cardiac progenitors into the heart, impaired myocyte proliferation, or both. We found that embryos deficient in scn5Lab displayed defects in primary cardiogenesis specific to loss of nkx2.5, but not nkx2.7. We generated kaede reporter fish and demonstrated that embryos treated with anti-scn5Lab morpholino showed normal secondary differentiation of cardiomyocytes at the arterial pole between 30 and 48 h post-fertilization. However, while proliferating myocytes were readily detected at 48 hpf in wild type embryos, there were no BrdU-positive cardiomyocytes in embryos subjected to anti-scn5Lab treatment. Proliferating myocytes were present in embryos injected with anti-tnnt2 morpholino to phenocopy the silent heart mutation, and absent in embryos injected with anti-tnnt2 and anti-scn5Lab morpholinos, indicating cardiac contraction is not required for the loss of proliferation. These data demonstrate that the role of scn5Lab in later heart growth does not involve contribution of the secondary heart field, but rather proliferation of cardiomyocytes, and appears unrelated to the role of the channel in cardiac electrogenesis.
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Affiliation(s)
- J S Bennett
- Program in Human Genetics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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164
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In vivo cardiac reprogramming contributes to zebrafish heart regeneration. Nature 2013; 498:497-501. [PMID: 23783515 PMCID: PMC4090927 DOI: 10.1038/nature12322] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 05/23/2013] [Indexed: 12/20/2022]
Abstract
Despite current treatment regimens, heart failure remains the leading cause of morbidity and mortality in the developed world due to the limited capacity of adult mammalian ventricular cardiomyocytes to divide and replace ventricular myocardium lost from ischemia-induced infarct1,2. As a result, there is great interest to identify potential cellular sources and strategies to generate new ventricular myocardium3. Past studies have shown that lower vertebrate and early postnatal mammalian ventricular cardiomyocytes can proliferate to help regenerate injured ventricles4–6; however, recent studies have suggested that additional endogenous cellular sources may contribute to this overall ventricular regeneration3. Here, we have developed in the zebrafish a combination of fluorescent reporter transgenes, genetic fate-mapping strategies, and a ventricle-specific genetic ablation system to discover that differentiated atrial cardiomyocytes can transdifferentiate into ventricular cardiomyocytes to contribute to zebrafish cardiac ventricular regeneration. Using in vivo time-lapse and confocal imaging, we monitored the dynamic cellular events during atrial-to-ventricular cardiomyocyte transdifferentiation to define intermediate cardiac reprogramming stages. Importantly, we observed that Notch signaling becomes activated in the atrial endocardium following ventricular ablation, and discovered that inhibiting Notch signaling blocked the atrial-to-ventricular transdifferentiation and cardiac regeneration. Overall, these studies not only provide evidence for the plasticity of cardiac lineages during myocardial injury, but more importantly reveal an abundant new potential cardiac resident cellular source for cardiac ventricular regeneration.
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165
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Sorrell MRJ, Dohn TE, D'Aniello E, Waxman JS. Tcf7l1 proteins cell autonomously restrict cardiomyocyte and promote endothelial specification in zebrafish. Dev Biol 2013; 380:199-210. [PMID: 23707897 DOI: 10.1016/j.ydbio.2013.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 05/12/2013] [Accepted: 05/13/2013] [Indexed: 11/24/2022]
Abstract
Tcf7l1 (formerly Tcf3) proteins are conserved transcription factors whose function as transcriptional repressors is relieved through interactions with β-catenin. Although the functions of Tcf7l1 proteins have been studied in many developmental contexts, whether this conserved mediator of Wnt signaling is required for appropriate cardiomyocyte (CM) development has not been investigated. We find that Tcf7l1 proteins are necessary during two developmental periods to limit CM number in zebrafish embryos: prior to gastrulation and after the initial wave of CM differentiation. In contrast to partially redundant roles in anterior neural patterning, we find that Tcf7l1a and Tcf7l1b have non-redundant functions with respect to restricting CM specification during anterior mesodermal patterning, suggesting that between the two zebrafish Tcf7l1 paralogs there is a limit to the transcriptional repression provided during early CM specification. Using cell transplantation experiments, we determine that the Tcf7l1 paralogs are required cell autonomously to restrict CM specification and promote endothelial cell (EC) specification, which is overtly similar to the ability of Wnt signaling to direct a transformation between these progenitors in embryonic stem cells. Therefore, these results argue that during anterior-posterior patterning of the mesoderm Tcf7l1 proteins are cell autonomously required to limit Wnt signaling, which balances CM and EC progenitor specification within the anterior lateral plate mesoderm. This study expands our understanding of the in vivo developmental requirements of Tcf7l1 proteins and the mechanisms directing CM development in vertebrates.
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Affiliation(s)
- Mollie R J Sorrell
- Molecular Cardiovascular Biology Division and The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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166
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Guner-Ataman B, Paffett-Lugassy N, Adams MS, Nevis KR, Jahangiri L, Obregon P, Kikuchi K, Poss KD, Burns CE, Burns CG. Zebrafish second heart field development relies on progenitor specification in anterior lateral plate mesoderm and nkx2.5 function. Development 2013; 140:1353-63. [PMID: 23444361 DOI: 10.1242/dev.088351] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Second heart field (SHF) progenitors perform essential functions during mammalian cardiogenesis. We recently identified a population of cardiac progenitor cells (CPCs) in zebrafish expressing latent TGFβ-binding protein 3 (ltbp3) that exhibits several defining characteristics of the anterior SHF in mammals. However, ltbp3 transcripts are conspicuously absent in anterior lateral plate mesoderm (ALPM), where SHF progenitors are specified in higher vertebrates. Instead, ltbp3 expression initiates at the arterial pole of the developing heart tube. Because the mechanisms of cardiac development are conserved evolutionarily, we hypothesized that zebrafish SHF specification also occurs in the ALPM. To test this hypothesis, we Cre/loxP lineage traced gata4(+) and nkx2.5(+) ALPM populations predicted to contain SHF progenitors, based on evolutionary conservation of ALPM patterning. Traced cells were identified in SHF-derived distal ventricular myocardium and in three lineages in the outflow tract (OFT). We confirmed the extent of contributions made by ALPM nkx2.5(+) cells using Kaede photoconversion. Taken together, these data demonstrate that, as in higher vertebrates, zebrafish SHF progenitors are specified within the ALPM and express nkx2.5. Furthermore, we tested the hypothesis that Nkx2.5 plays a conserved and essential role during zebrafish SHF development. Embryos injected with an nkx2.5 morpholino exhibited SHF phenotypes caused by compromised progenitor cell proliferation. Co-injecting low doses of nkx2.5 and ltbp3 morpholinos revealed a genetic interaction between these factors. Taken together, our data highlight two conserved features of zebrafish SHF development, reveal a novel genetic relationship between nkx2.5 and ltbp3, and underscore the utility of this model organism for deciphering SHF biology.
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Affiliation(s)
- Burcu Guner-Ataman
- Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, MA 02129, USA
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167
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Rodríguez C, Sans-Coma V, Grimes AC, Fernández B, Arqué JM, Durán AC. Embryonic development of the bulbus arteriosus of the primitive heart of jawed vertebrates. ZOOL ANZ 2013. [DOI: 10.1016/j.jcz.2012.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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168
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Stuckenholz C, Lu L, Thakur PC, Choi TY, Shin D, Bahary N. Sfrp5 modulates both Wnt and BMP signaling and regulates gastrointestinal organogenesis [corrected] in the zebrafish, Danio rerio. PLoS One 2013; 8:e62470. [PMID: 23638093 PMCID: PMC3639276 DOI: 10.1371/journal.pone.0062470] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 03/21/2013] [Indexed: 02/08/2023] Open
Abstract
Sfrp5 belongs to the family of secreted frizzled related proteins (Sfrp), secreted inhibitors of Wingless-MMTV Integration Site (Wnt) signaling, which play an important role in cancer and development. We selected sfrp5 because of its compelling expression profile in the developing endoderm in zebrafish, Danio rerio. In this study, overexpression of sfrp5 in embryos results in defects in both convergent extension (CE) by inhibition of non-canonical Wnt signaling and defects in dorsoventral patterning by inhibition of Tolloid-mediated proteolysis of the BMP inhibitor Chordin. From 25 hours post fertilization (hpf) to 3 days post fertilization (dpf), both overexpression and knockdown of Sfrp5 decrease the size of the endoderm, significantly reducing liver cell number. At 3 dpf, insulin-positive endodermal cells fail to coalesce into a single pancreatic islet. We show that Sfrp5 inhibits both canonical and non-canonical Wnt signaling during embryonic and endodermal development, resulting in endodermal abnormalities.
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Affiliation(s)
- Carsten Stuckenholz
- Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Lili Lu
- Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Prakash C. Thakur
- Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Tae-Young Choi
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Donghun Shin
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Nathan Bahary
- Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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169
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Choudhry P, Trede NS. DiGeorge syndrome gene tbx1 functions through wnt11r to regulate heart looping and differentiation. PLoS One 2013; 8:e58145. [PMID: 23533583 PMCID: PMC3606275 DOI: 10.1371/journal.pone.0058145] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/31/2013] [Indexed: 01/31/2023] Open
Abstract
DiGeorge syndrome (DGS) is the most common microdeletion syndrome, and is characterized by congenital cardiac, craniofacial and immune system abnormalities. The cardiac defects in DGS patients include conotruncal and ventricular septal defects. Although the etiology of DGS is critically regulated by TBX1 gene, the molecular pathways underpinning TBX1's role in heart development are not fully understood. In this study, we characterized heart defects and downstream signaling in the zebrafish tbx1−/− mutant, which has craniofacial and immune defects similar to DGS patients. We show that tbx1−/− mutants have defective heart looping, morphology and function. Defective heart looping is accompanied by failure of cardiomyocytes to differentiate normally and failure to change shape from isotropic to anisotropic morphology in the outer curvatures of the heart. This is the first demonstration of tbx1's role in regulating heart looping, cardiomyocyte shape and differentiation, and may explain how Tbx1 regulates conotruncal development in humans. Next we elucidated tbx1's molecular signaling pathway guided by the cardiac phenotype of tbx1−/− mutants. We show for the first time that wnt11r (wnt11 related), a member of the non-canonical Wnt pathway, and its downstream effector gene alcama (activated leukocyte cell adhesion molecule a) regulate heart looping and differentiation similarly to tbx1. Expression of both wnt11r and alcama are downregulated in tbx1−/− mutants. In addition, both wnt11r−/− mutants and alcama morphants have heart looping and differentiation defects similar to tbx1−/− mutants. Strikingly, heart looping and differentiation in tbx1−/− mutants can be partially rescued by ectopic expression of wnt11r or alcama, supporting a model whereby heart looping and differentiation are regulated by tbx1 in a linear pathway through wnt11r and alcama. This is the first study linking tbx1 and non-canonical Wnt signaling and extends our understanding of DGS and heart development.
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Affiliation(s)
- Priya Choudhry
- Huntsman Cancer Institute, Department of Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail: (PC) (PC); (NT) (NT)
| | - Nikolaus S. Trede
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail: (PC) (PC); (NT) (NT)
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170
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Nevis K, Obregon P, Walsh C, Guner-Ataman B, Burns CG, Burns CE. Tbx1 is required for second heart field proliferation in zebrafish. Dev Dyn 2013; 242:550-9. [PMID: 23335360 DOI: 10.1002/dvdy.23928] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 01/03/2013] [Accepted: 01/03/2013] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND The mammalian outflow tract (OFT) and primitive right ventricle arise by accretion of newly differentiated cells to the arterial pole of the heart tube from multi-potent progenitor cells of the second heart field (SHF). While mounting evidence suggests that the genetic pathways regulating SHF development are highly conserved in zebrafish, this topic remains an active area of investigation. RESULTS Here, we extend previous observations demonstrating that zebrafish tbx1 (van gogh, vgo) mutants show ventricular and OFT defects consistent with a conserved role in SHF-mediated cardiogenesis. Surprisingly, we reveal through double in situ analyses that tbx1 transcripts are excluded from cardiac progenitor cells and differentiated cardiomyocytes, suggesting a non-autonomous role in SHF development. Further, we find that the diminutive ventricle in vgo animals results from a 25% decrease in cardiomyocyte number that occurs subsequent to heart tube stages. Lastly, we report that although SHF progenitors are specified in the absence of Tbx1, they fail to be maintained due to compromised SHF progenitor cell proliferation. CONCLUSIONS These studies highlight conservation of Tbx1 function in zebrafish SHF biology.
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Affiliation(s)
- Kathleen Nevis
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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171
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Opitz R, Maquet E, Huisken J, Antonica F, Trubiroha A, Pottier G, Janssens V, Costagliola S. Transgenic zebrafish illuminate the dynamics of thyroid morphogenesis and its relationship to cardiovascular development. Dev Biol 2012; 372:203-16. [PMID: 23022354 DOI: 10.1016/j.ydbio.2012.09.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 07/22/2012] [Accepted: 09/17/2012] [Indexed: 11/18/2022]
Abstract
Among the various organs derived from foregut endoderm, the thyroid gland is unique in that major morphogenic events such as budding from foregut endoderm, descent into subpharyngeal mesenchyme and growth expansion occur in close proximity to cardiovascular tissues. To date, research on thyroid organogenesis was missing one vital tool-a transgenic model that allows to track the dynamic changes in thyroid size, shape and location relative to adjacent cardiovascular tissues in live embryos. In this study, we generated a novel transgenic zebrafish line, tg(tg:mCherry), in which robust and thyroid-specific expression of a membrane version of mCherry enables live imaging of thyroid development in embryos from budding stage throughout formation of functional thyroid follicles. By using various double transgenic models in which EGFP expression additionally labels cardiovascular structures, a high coordination was revealed between thyroid organogenesis and cardiovascular development. Early thyroid development was found to proceed in intimate contact with the distal ventricular myocardium and live imaging confirmed that thyroid budding from the pharyngeal floor is tightly coordinated with the descent of the heart. Four-dimensional imaging of live embryos by selective plane illumination microscopy and 3D-reconstruction of confocal images of stained embryos yielded novel insights into the role of specific pharyngeal vessels, such as the hypobranchial artery (HA), in guiding late thyroid expansion along the pharyngeal midline. An important role of the HA was corroborated by the detailed examination of thyroid development in various zebrafish models showing defective cardiovascular development. In combination, our results from live imaging as well es from 3D-reconstruction of thyroid development in tg(tg:mCherry) embryos provided a first dynamic view of late thyroid organogenesis in zebrafish-a critical resource for the design of future studies addressing the molecular mechanisms of these thyroid-vasculature interactions.
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Affiliation(s)
- Robert Opitz
- Institute of Interdisciplinary Research in Molecular Human Biology (IRIBHM), Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
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172
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Staudt D, Stainier D. Uncovering the molecular and cellular mechanisms of heart development using the zebrafish. Annu Rev Genet 2012; 46:397-418. [PMID: 22974299 DOI: 10.1146/annurev-genet-110711-155646] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Over the past 20 years, the zebrafish has emerged as a powerful model organism for studying cardiac development. Its ability to survive without an active circulation and amenability to forward genetics has led to the identification of numerous mutants whose study has helped elucidate new mechanisms in cardiac development. Furthermore, its transparent, externally developing embryos have allowed detailed cellular analyses of heart development. In this review, we discuss the molecular and cellular processes involved in zebrafish heart development from progenitor specification to development of the valve and the conduction system. We focus on imaging studies that have uncovered the cellular bases of heart development and on zebrafish mutants with cardiac abnormalities whose study has revealed novel molecular pathways in cardiac cell specification and tissue morphogenesis.
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Affiliation(s)
- David Staudt
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA
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173
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Zhen YS, Wu Q, Xiao CL, Chang NN, Wang X, Lei L, Zhu X, Xiong JW. Overlapping cardiac programs in heart development and regeneration. J Genet Genomics 2012; 39:443-9. [PMID: 23021544 DOI: 10.1016/j.jgg.2012.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 07/02/2012] [Accepted: 07/07/2012] [Indexed: 02/03/2023]
Abstract
Gaining cellular and molecular insights into heart development and regeneration will likely provide new therapeutic targets and opportunities for cardiac regenerative medicine, one of the most urgent clinical needs for heart failure. Here we present a review on zebrafish heart development and regeneration, with a particular focus on early cardiac progenitor development and their contribution to building embryonic heart, as well as cellular and molecular programs in adult zebrafish heart regeneration. We attempt to emphasize that the signaling pathways shaping cardiac progenitors in heart development may also be redeployed during the progress of adult heart regeneration. A brief perspective highlights several important and promising research areas in this exciting field.
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Affiliation(s)
- Yi-Song Zhen
- Institute of Molecular Medicine, Peking University, Beijing, China
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174
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Cai W, Guzzo RM, Wei K, Willems E, Davidovics H, Mercola M. A Nodal-to-TGFβ cascade exerts biphasic control over cardiopoiesis. Circ Res 2012; 111:876-81. [PMID: 22872153 DOI: 10.1161/circresaha.112.270272] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE The transforming growth factor-β (TGFβ) family member Nodal promotes cardiogenesis, but the mechanism is unclear despite the relevance of TGFβ family proteins for myocardial remodeling and regeneration. OBJECTIVE To determine the function(s) of TGFβ family members during stem cell cardiogenesis. METHODS AND RESULTS Murine embryonic stem cells were engineered with a constitutively active human type I Nodal receptor (caACVR1b) to mimic activation by Nodal and found to secrete a paracrine signal that promotes cardiogenesis. Transcriptome and gain- and loss-of-function studies identified the factor as TGFβ2. Both Nodal and TGFβ induced early cardiogenic progenitors in embryonic stem cell cultures at day 0 to 2 of differentiation. However, Nodal expression declines by day 4 due to feedback inhibition, whereas TGFβ persists. At later stages (days 4-6), TGFβ suppresses the formation of cardiomyocytes from multipotent Kdr(+) progenitors while promoting the differentiation of vascular smooth muscle and endothelial cells. CONCLUSIONS Nodal induces TGFβ, and both stimulate the formation of multipotent cardiovascular Kdr(+) progenitors. TGFβ, however, becomes uniquely responsible for controlling subsequent lineage segregation by stimulating vascular smooth muscle and endothelial lineages and simultaneously blocking cardiomyocyte differentiation.
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Affiliation(s)
- Wenqing Cai
- Muscle Development and Regeneration Program, Sanford-Burnham Medical Research Institute, 10901 N Torrey Pines Rd, La Jolla, CA 92037, USA
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175
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Witzel HR, Jungblut B, Choe CP, Crump JG, Braun T, Dobreva G. The LIM protein Ajuba restricts the second heart field progenitor pool by regulating Isl1 activity. Dev Cell 2012; 23:58-70. [PMID: 22771034 DOI: 10.1016/j.devcel.2012.06.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 03/16/2012] [Accepted: 06/04/2012] [Indexed: 11/26/2022]
Abstract
Morphogenesis of the heart requires tight control of cardiac progenitor cell specification, expansion, and differentiation. Retinoic acid (RA) signaling restricts expansion of the second heart field (SHF), serving as an important morphogen in heart development. Here, we identify the LIM domain protein Ajuba as a crucial regulator of the SHF progenitor cell specification and expansion. Ajuba-deficient zebrafish embryos show an increased pool of Isl1(+) cardiac progenitors and, subsequently, dramatically increased numbers of cardiomyocytes at the arterial and venous poles. Furthermore, we show that Ajuba binds Isl1, represses its transcriptional activity, and is also required for autorepression of Isl1 expression in an RA-dependent manner. Lack of Ajuba abrogates the RA-dependent restriction of Isl1(+) cardiac cells. We conclude that Ajuba plays a central role in regulating the SHF during heart development by linking RA signaling to the function of Isl1, a key transcription factor in cardiac progenitor cells.
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Affiliation(s)
- Hagen R Witzel
- Origin of Cardiac Cell Lineages Group, Max Planck Institute for Heart and Lung Research, Parkstrasse 1, Bad Nauheim, Germany
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176
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New developments in the second heart field. Differentiation 2012; 84:17-24. [DOI: 10.1016/j.diff.2012.03.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/24/2012] [Accepted: 03/07/2012] [Indexed: 11/18/2022]
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177
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Norden J, Kispert A. Wnt/Ctnnb1 Signaling and the Mesenchymal Precursor Pools of the Heart. Trends Cardiovasc Med 2012; 22:118-22. [DOI: 10.1016/j.tcm.2012.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 02/01/2023]
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178
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Chin AJ, Saint-Jeannet JP, Lo CW. How insights from cardiovascular developmental biology have impacted the care of infants and children with congenital heart disease. Mech Dev 2012; 129:75-97. [PMID: 22640994 PMCID: PMC3409324 DOI: 10.1016/j.mod.2012.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/23/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
To illustrate the impact developmental biology and genetics have already had on the clinical management of the million infants born worldwide each year with CHD, we have chosen three stories which have had particular relevance for pediatric cardiologists, cardiothoracic surgeons, cardiac anesthesiologists, and cardiac nurses. First, we show how Margaret Kirby's finding of the unexpected contribution of an ectodermal cell population - the cranial neural crest - to the aortic arch arteries and arterial pole of the embryonic avian heart provided a key impetus to the field of cardiovascular patterning. Recognition that a majority of patients affected by the neurocristopathy DiGeorge syndrome have a chromosome 22q11 deletion, have also spurred tremendous efforts to characterize the molecular mechanisms contributing to this pathology, assigning a major role to the transcription factor Tbx1. Second, synthesizing the work of the last two decades by many laboratories on a wide gamut of metazoans (invertebrates, tunicates, agnathans, teleosts, lungfish, amphibians, and amniotes), we review the >20 major modifications and additions to the ancient circulatory arrangement composed solely of a unicameral (one-chambered), contractile myocardial tube and a short proximal aorta. Two changes will be discussed in detail - the interposition of a second cardiac chamber in the circulation and the septation of the cardiac ventricle. By comparing the developmental genetic data of several model organisms, we can better understand the origin of the various components of the multicameral (multi-chambered) heart seen in humans. Third, Martina Brueckner's discovery that a faulty axonemal dynein was responsible for the phenotype of the iv/iv mouse (the first mammalian model of human heterotaxy) focused attention on the biology of cilia. We discuss how even the care of the complex cardiac and non-cardiac anomalies seen in heterotaxy syndrome, which have long seemed impervious to advancements in surgical and medical intensive care, may yet yield to strategies grounded in a better understanding of the cilium. The fact that all cardiac defects seen in patients with full-blown heterotaxy can also be seen in patients without obvious laterality defects hints at important roles for ciliary function not only in left-right axis specification but also in cardiovascular morphogenesis. These three developmental biology stories illustrate how the remaining unexplained mortality and morbidity of congenital heart disease can be solved.
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Affiliation(s)
- Alvin J Chin
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, United States.
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179
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Zebrafish Mef2ca and Mef2cb are essential for both first and second heart field cardiomyocyte differentiation. Dev Biol 2012; 369:199-210. [PMID: 22750409 DOI: 10.1016/j.ydbio.2012.06.019] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 06/07/2012] [Accepted: 06/20/2012] [Indexed: 01/17/2023]
Abstract
Mef2 transcription factors have been strongly linked with early heart development. D-mef2 is required for heart formation in Drosophila, but whether Mef2 is essential for vertebrate cardiomyocyte (CM) differentiation is unclear. In mice, although Mef2c is expressed in all CMs, targeted deletion of Mef2c causes lethal loss of second heart field (SHF) derivatives and failure of cardiac looping, but first heart field CMs can differentiate. Here we examine Mef2 function in early heart development in zebrafish. Two Mef2c genes exist in zebrafish, mef2ca and mef2cb. Both are expressed similarly in the bilateral heart fields but mef2cb is strongly expressed in the heart poles at the primitive heart tube stage. By using fish mutants for mef2ca and mef2cb and antisense morpholinos to knock down either or both Mef2cs, we show that Mef2ca and Mef2cb have essential but redundant roles in myocardial differentiation. Loss of both Mef2ca and Mef2cb function does not interfere with early cardiogenic markers such as nkx2.5, gata4 and hand2 but results in a dramatic loss of expression of sarcomeric genes and myocardial markers such as bmp4, nppa, smyd1b and late nkx2.5 mRNA. Rare residual CMs observed in mef2ca;mef2cb double mutants are ablated by a morpholino capable of knocking down other Mef2s. Mef2cb over-expression activates bmp4 within the cardiogenic region, but no ectopic CMs are formed. Surprisingly, anterior mesoderm and other tissues become skeletal muscle. Mef2ca single mutants have delayed heart development, but form an apparently normal heart. Mef2cb single mutants have a functional heart and are viable adults. Our results show that the key role of Mef2c in myocardial differentiation is conserved throughout the vertebrate heart.
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180
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Tu S, Chi NC. Zebrafish models in cardiac development and congenital heart birth defects. Differentiation 2012; 84:4-16. [PMID: 22704690 DOI: 10.1016/j.diff.2012.05.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 05/02/2012] [Accepted: 05/21/2012] [Indexed: 12/31/2022]
Abstract
The zebrafish has become an ideal vertebrate animal system for investigating cardiac development due to its genetic tractability, external fertilization, early optical clarity and ability to survive without a functional cardiovascular system during development. In particular, recent advances in imaging techniques and the creation of zebrafish transgenics now permit the in vivo analysis of the dynamic cellular events that transpire during cardiac morphogenesis. As a result, the combination of these salient features provides detailed insight as to how specific genes may influence cardiac development at the cellular level. In this review, we will highlight how the zebrafish has been utilized to elucidate not only the underlying mechanisms of cardiac development and human congenital heart diseases (CHDs), but also potential pathways that may modulate cardiac regeneration. Thus, we have organized this review based on the major categories of CHDs-structural heart, functional heart, and vascular/great vessel defects, and will conclude with how the zebrafish may be further used to contribute to our understanding of specific human CHDs in the future.
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Affiliation(s)
- Shu Tu
- Department of Medicine, Division of Cardiology, University of California, San Diego, CA 92093-0613J, USA
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181
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Organogenesis of the vertebrate heart. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 2:17-29. [DOI: 10.1002/wdev.68] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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182
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Abstract
Heart development is a complex process that involves cell specification and differentiation, as well as elaborate tissue morphogenesis and remodeling, to generate a functional organ. The zebrafish has emerged as a powerful model system to unravel the basic genetic, molecular, and cellular mechanisms of cardiac development and function. We summarize and discuss recent discoveries on early cardiac specification and the identification of the second heart field in zebrafish. In addition to the inductive signals regulating cardiac specification, these studies have shown that heart development also requires a repressive mechanism imposed by retinoic acid signaling to select cardiac progenitors from a multipotent population. Another recent advance in the study of early zebrafish cardiac development is the identification of the second heart field. These studies suggest that the molecular mechanisms that regulate the second heart field development are conserved between zebrafish and other vertebrates including mammals and provide insight into the evolution of the second heart field and its derivatives.
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Affiliation(s)
- Jiandong Liu
- Department of Biochemistry and Biophysics, University of California, San Francisco, USA.
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183
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Gupta V, Poss KD. Clonally dominant cardiomyocytes direct heart morphogenesis. Nature 2012; 484:479-84. [PMID: 22538609 PMCID: PMC3340018 DOI: 10.1038/nature11045] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Accepted: 03/15/2012] [Indexed: 12/23/2022]
Abstract
As vertebrate embryos develop to adulthood, their organs undergo marked changes in size and tissue architecture. The heart acquires muscle mass and matures structurally to fulfil increasing circulatory needs, a process that is incompletely understood. Here we used multicolour clonal analysis to define the contributions of individual cardiomyocytes as the zebrafish heart undergoes morphogenesis from a primitive embryonic structure into its complex adult form. We find that the single-cardiomyocyte-thick wall of the juvenile ventricle forms by lateral expansion of several dozen cardiomyocytes into muscle patches of variable sizes and shapes. As juvenile zebrafish mature into adults, this structure becomes fully enveloped by a new lineage of cortical muscle. Adult cortical muscle originates from a small number of cardiomyocytes--an average of approximately eight per animal--that display clonal dominance reminiscent of stem cell populations. Cortical cardiomyocytes initially emerge from internal myofibres that in rare events breach the juvenile ventricular wall, and then expand over the surface. Our results illuminate the dynamic proliferative behaviours that generate adult cardiac structure, revealing clonal dominance as a key mechanism that shapes a vertebrate organ.
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Affiliation(s)
- Vikas Gupta
- Department of Cell Biology and Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA
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184
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Islet1-expressing cardiac progenitor cells: a comparison across species. Dev Genes Evol 2012; 223:117-29. [PMID: 22526874 PMCID: PMC3552366 DOI: 10.1007/s00427-012-0400-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 04/03/2012] [Indexed: 01/05/2023]
Abstract
Adult mammalian cardiac stem cells express the LIM-homeodomain transcription factor Islet1 (Isl1). They are considered remnants of Isl1-positive embryonic cardiac progenitor cells. During amniote heart development, Isl1-positive progenitor cells give rise mainly to the outflow tract, the right ventricle, and parts of the atria. This led to the hypothesis that the development of the right ventricle of the amniote heart depends on the recruitment of additional cells to the primary heart tube. The region from which these additional, Isl1-positive cells originate is called second heart field, as opposed to the first heart field whose cells form the primary heart tube. Here, we review the available data about Isl1 in different species, demonstrating that Isl1 is an important component of the core transcription factor network driving early cardiogenesis in animals of the two clades, deuterostomes, and protostomes. The data support the view of a single cardiac progenitor cell population that includes Isl1-expressing cells and which differentiates into the various cardiac lineages during embryonic development in vertebrates but not in other phyla of the animal kingdom.
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185
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Golzio C, Havis E, Daubas P, Nuel G, Babarit C, Munnich A, Vekemans M, Zaffran S, Lyonnet S, Etchevers HC. ISL1 directly regulates FGF10 transcription during human cardiac outflow formation. PLoS One 2012; 7:e30677. [PMID: 22303449 PMCID: PMC3267757 DOI: 10.1371/journal.pone.0030677] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 12/20/2011] [Indexed: 11/23/2022] Open
Abstract
The LIM homeodomain gene Islet-1 (ISL1) encodes a transcription factor that has been associated with the multipotency of human cardiac progenitors, and in mice enables the correct deployment of second heart field (SHF) cells to become the myocardium of atria, right ventricle and outflow tract. Other markers have been identified that characterize subdomains of the SHF, such as the fibroblast growth factor Fgf10 in its anterior region. While functional evidence of its essential contribution has been demonstrated in many vertebrate species, SHF expression of Isl1 has been shown in only some models. We examined the relationship between human ISL1 and FGF10 within the embryonic time window during which the linear heart tube remodels into four chambers. ISL1 transcription demarcated an anatomical region supporting the conserved existence of a SHF in humans, and transcription factors of the GATA family were co-expressed therein. In conjunction, we identified a novel enhancer containing a highly conserved ISL1 consensus binding site within the FGF10 first intron. ChIP and EMSA demonstrated its direct occupation by ISL1. Transcription mediated by ISL1 from this FGF10 intronic element was enhanced by the presence of GATA4 and TBX20 cardiac transcription factors. Finally, transgenic mice confirmed that endogenous factors bound the human FGF10 intronic enhancer to drive reporter expression in the developing cardiac outflow tract. These findings highlight the interest of examining developmental regulatory networks directly in human tissues, when possible, to assess candidate non-coding regions that may be responsible for congenital malformations.
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Affiliation(s)
- Christelle Golzio
- Center for Human Disease Modeling, Department of Cell Biology, Duke Medical Center, Durham, North Carolina, United States of America
| | | | | | - Gregory Nuel
- CNRS 8145, Mathématiques appliquées, Université Paris Descartes, Paris, France
| | - Candice Babarit
- INSERM U781, Université Paris Descartes, Faculté de Médecine, Paris, France
| | - Arnold Munnich
- INSERM U781, Université Paris Descartes, Faculté de Médecine, Paris, France
- Service de Génétique Médicale, Hôpital Necker-Enfants Malades, Paris, France
| | - Michel Vekemans
- INSERM U781, Université Paris Descartes, Faculté de Médecine, Paris, France
- Service de Génétique Médicale, Hôpital Necker-Enfants Malades, Paris, France
| | - Stéphane Zaffran
- INSERM, U910, Marseille, France; Aix-Marseille Univ, Faculté de Médecine, UMR 910, Marseille, France
| | - Stanislas Lyonnet
- INSERM U781, Université Paris Descartes, Faculté de Médecine, Paris, France
- Service de Génétique Médicale, Hôpital Necker-Enfants Malades, Paris, France
| | - Heather C. Etchevers
- INSERM, U910, Marseille, France; Aix-Marseille Univ, Faculté de Médecine, UMR 910, Marseille, France
- * E-mail:
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186
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Abstract
Ten years ago, a population of cardiac progenitor cells was identified in pharyngeal mesoderm that gives rise to a major part of the amniote heart. These multipotent progenitor cells, termed the second heart field (SHF), contribute progressively to the poles of the elongating heart tube during looping morphogenesis, giving rise to myocardium, smooth muscle, and endothelial cells. Research into the mechanisms of SHF development has contributed significantly to our understanding of the properties of cardiac progenitor cells and the origins of congenital heart defects. Here recent data concerning the regulation, clinically relevant subpopulations, evolution and lineage relationships of the SHF are reviewed. Proliferation and differentiation of SHF cells are controlled by multiple intercellular signaling pathways and a transcriptional regulatory network that is beginning to be elucidated. Perturbation of SHF development results in common forms of congenital heart defects and particular progenitor cell subpopulations are highly relevant clinically, including cells giving rise to myocardium at the base of the pulmonary trunk and the interatrial septum. A SHF has recently been identified in amphibian, fish, and agnathan embryos, highlighting the important contribution of these cells to the evolution of the vertebrate heart. Finally, SHF-derived parts of the heart share a lineage relationship with craniofacial skeletal muscles revealing that these progenitor cells belong to a broad cardiocraniofacial field of pharyngeal mesoderm. Investigation of the mechanisms underlying the dynamic process of SHF deployment is likely to yield further insights into cardiac development and pathology.
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Affiliation(s)
- Robert G Kelly
- Developmental Biology Institute of Marseilles-Luminy, Aix-Marseille Université, CNRS UMR 7288, Marseilles, France
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187
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Distinct phases of Wnt/β-catenin signaling direct cardiomyocyte formation in zebrafish. Dev Biol 2011; 361:364-76. [PMID: 22094017 DOI: 10.1016/j.ydbio.2011.10.032] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 10/25/2011] [Accepted: 10/27/2011] [Indexed: 02/02/2023]
Abstract
Normal heart formation requires reiterative phases of canonical Wnt/β-catenin (Wnt) signaling. Understanding the mechanisms by which Wnt signaling directs cardiomyocyte (CM) formation in vivo is critical to being able to precisely direct differentiated CMs from stem cells in vitro. Here, we investigate the roles of Wnt signaling in zebrafish CM formation using heat-shock inducible transgenes that increase and decrease Wnt signaling. We find that there are three phases during which CM formation is sensitive to modulation of Wnt signaling through the first 24 h of development. In addition to the previously recognized roles for Wnt signaling during mesoderm specification and in the pre-cardiac mesoderm, we find a previously unrecognized role during CM differentiation where Wnt signaling is necessary and sufficient to promote the differentiation of additional atrial cells. We also extend the previous studies of the roles of Wnt signaling during mesoderm specification and in pre-cardiac mesoderm. Importantly, in pre-cardiac mesoderm we define a new mechanism where Wnt signaling is sufficient to prevent CM differentiation, in contrast to a proposed role in inhibiting cardiac progenitor (CP) specification. The inability of the CPs to differentiate appears to lead to cell death through a p53/Caspase-3 independent mechanism. Together with a report for an even later role for Wnt signaling in restricting proliferation of differentiated ventricular CMs, our results indicate that during the first 3days of development in zebrafish there are four distinct phases during which CMs are sensitive to Wnt signaling.
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188
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Simões FC, Peterkin T, Patient R. Fgf differentially controls cross-antagonism between cardiac and haemangioblast regulators. Development 2011; 138:3235-45. [PMID: 21750034 DOI: 10.1242/dev.059634] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fibroblast growth factor (Fgf) has been implicated in the control of heart size during development, although whether this is by controlling cell fate, survival or proliferation has not been clear. Here, we show that Fgf, without affecting survival or proliferation, acts during gastrulation to drive cardiac fate and restrict anterior haemangioblast fate in zebrafish embryos. The haemangioblast programme was thought to be activated before the cardiac programme and is repressive towards it, suggesting that activation by Fgf of the cardiac programme might be via suppression of the haemangioblast programme. However, we show that the cardiac regulator nkx2.5 can also repress the haemangioblast programme and, furthermore, that cardiac specification still requires Fgf signalling even when haemangioblast regulators are independently suppressed. We further show that nkx2.5 and the cloche candidate gene lycat are expressed during gastrulation and regulated by Fgf, and that nkx2.5 overexpression, together with loss of the lycat targets etsrp and scl can stably induce expansion of the heart. We conclude that Fgf controls cardiac and haemangioblast fates by the simultaneous regulation of haemangioblast and cardiac regulators. We propose that elevation of Fgf signalling in the anterior haemangioblast territory could have led to its recruitment into the heart field during evolution, increasing the size of the heart.
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Affiliation(s)
- Filipa Costa Simões
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford University, John Radcliffe Hospital, Headington OX3 9DS, UK
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