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  1. Article ; Online: Dual role for CXCL12 signaling in semilunar valve development

    Liam A. Ridge / Dania Kewbank / Dagmar Schütz / Ralf Stumm / Peter J. Scambler / Sarah Ivins

    Cell Reports, Vol 36, Iss 8, Pp 109610- (2021)

    2021  

    Abstract: Summary: 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 ... ...

    Abstract Summary: 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.
    Keywords cell migration ; CXCL12 ; CXCR4 ; CXCR7 ; outflow tract ; semilunar valves ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2021-08-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Loss of CXCL12/CXCR4 signalling impacts several aspects of cardiovascular development but does not exacerbate Tbx1 haploinsufficiency.

    Mahalia Page / Liam Ridge / Diana Gold Diaz / Tsolmon Tsogbayar / Peter J Scambler / Sarah Ivins

    PLoS ONE, Vol 13, Iss 11, p e

    2018  Volume 0207251

    Abstract: The CXCL12-CXCR4 pathway has crucial roles in stem cell homing and maintenance, neuronal guidance, cancer progression, inflammation, remote-conditioning, cell migration and development. Recently, work in chick suggested that signalling via CXCR4 in ... ...

    Abstract The CXCL12-CXCR4 pathway has crucial roles in stem cell homing and maintenance, neuronal guidance, cancer progression, inflammation, remote-conditioning, cell migration and development. Recently, work in chick suggested that signalling via CXCR4 in neural crest cells (NCCs) has a role in the 22q11.2 deletion syndrome (22q11.2DS), a disorder where haploinsufficiency of the transcription factor TBX1 is responsible for the major structural defects. We tested this idea in mouse models. Our analysis of genes with altered expression in Tbx1 mutant mouse models showed down-regulation of Cxcl12 in pharyngeal surface ectoderm and rostral mesoderm, both tissues with the potential to signal to migrating NCCs. Conditional mutagenesis of Tbx1 in the pharyngeal surface ectoderm is associated with hypo/aplasia of the 4th pharyngeal arch artery (PAA) and interruption of the aortic arch type B (IAA-B), the cardiovascular defect most typical of 22q11.2DS. We therefore analysed constitutive mouse mutants of the ligand (CXCL12) and receptor (CXCR4) components of the pathway, in addition to ectodermal conditionals of Cxcl12 and NCC conditionals of Cxcr4. However, none of these typical 22q11.2DS features were detected in constitutively or conditionally mutant embryos. Instead, duplicated carotid arteries were observed, a phenotype recapitulated in Tie-2Cre (endothelial) conditional knock outs of Cxcr4. Previous studies have demonstrated genetic interaction between signalling pathways and Tbx1 haploinsufficiency e.g. FGF, WNT, SMAD-dependent. We therefore tested for possible epistasis between Tbx1 and the CXCL12 signalling axis by examining Tbx1 and Cxcl12 double heterozygotes as well as Tbx1/Cxcl12/Cxcr4 triple heterozygotes, but failed to identify any exacerbation of the Tbx1 haploinsufficient arch artery phenotype. We conclude that CXCL12 signalling via NCC/CXCR4 has no major role in the genesis of the Tbx1 loss of function phenotype. Instead, the pathway has a distinct effect on remodelling of head vessels and interventricular ...
    Keywords Medicine ; R ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Tbx1 regulates the BMP-Smad1 pathway in a transcription independent manner.

    F Gabriella Fulcoli / Tuong Huynh / Peter J Scambler / Antonio Baldini

    PLoS ONE, Vol 4, Iss 6, p e

    2009  Volume 6049

    Abstract: Tbx1 is a T-box transcription factor implicated in DiGeorge syndrome. The molecular function of Tbx1 is unclear although it can transactivate reporters with T-box binding elements. We discovered that Tbx1 binds Smad1 and suppresses the Bmp4/Smad1 ... ...

    Abstract Tbx1 is a T-box transcription factor implicated in DiGeorge syndrome. The molecular function of Tbx1 is unclear although it can transactivate reporters with T-box binding elements. We discovered that Tbx1 binds Smad1 and suppresses the Bmp4/Smad1 signaling. Tbx1 interferes with Smad1 to Smad4 binding, and a mutation of Tbx1 that abolishes transactivation, does not affect Smad1 binding nor does affect the ability to suppress Smad1 activity. In addition, a disease-associated mutation of TBX1 that does not prevent transactivation, prevents the TBX1-SMAD1 interaction. Expression of Tbx1 in transgenic mice generates phenotypes similar to those associated with loss of a Bmp receptor. One phenotype could be rescued by transgenic Smad1 expression. Our data indicate that Tbx1 interferes with Bmp/Smad1 signaling and provide strong evidence that a T-box transcription factor has functions unrelated to transactivation.
    Keywords Medicine ; R ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2009-06-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: HIRA Is Required for Heart Development and Directly Regulates Tnni2 and Tnnt3.

    Daniel Dilg / Rasha Noureldin M Saleh / Sarah Elizabeth Lee Phelps / Yoann Rose / Laurent Dupays / Cian Murphy / Timothy Mohun / Robert H Anderson / Peter J Scambler / Ariane L A Chapgier

    PLoS ONE, Vol 11, Iss 8, p e

    2016  Volume 0161096

    Abstract: Chromatin remodelling is essential for cardiac development. Interestingly, the role of histone chaperones has not been investigated in this regard. HIRA is a member of the HUCA (HIRA/UBN1/CABIN1/ASF1a) complex that deposits the variant histone H3.3 on ... ...

    Abstract Chromatin remodelling is essential for cardiac development. Interestingly, the role of histone chaperones has not been investigated in this regard. HIRA is a member of the HUCA (HIRA/UBN1/CABIN1/ASF1a) complex that deposits the variant histone H3.3 on chromatin independently of replication. Lack of HIRA has general effects on chromatin and gene expression dynamics in embryonic stem cells and mouse oocytes. Here we describe the conditional ablation of Hira in the cardiogenic mesoderm of mice. We observed surface oedema, ventricular and atrial septal defects and embryonic lethality. We identified dysregulation of a subset of cardiac genes, notably upregulation of troponins Tnni2 and Tnnt3, involved in cardiac contractility and decreased expression of Epha3, a gene necessary for the fusion of the muscular ventricular septum and the atrioventricular cushions. We found that HIRA binds GAGA rich DNA loci in the embryonic heart, and in particular a previously described enhancer of Tnni2/Tnnt3 (TTe) bound by the transcription factor NKX2.5. HIRA-dependent H3.3 enrichment was observed at the TTe in embryonic stem cells (ESC) differentiated toward cardiomyocytes in vitro. Thus, we show here that HIRA has locus-specific effects on gene expression and that histone chaperone activity is vital for normal heart development, impinging on pathways regulated by an established cardiac transcription factor.
    Keywords Medicine ; R ; Science ; Q
    Subject code 570
    Language English
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: HIRA Is Required for Heart Development and Directly Regulates Tnni2 and Tnnt3.

    Daniel Dilg / Rasha Noureldin M Saleh / Sarah Elizabeth Lee Phelps / Yoann Rose / Laurent Dupays / Cian Murphy / Timothy Mohun / Robert H Anderson / Peter J Scambler / Ariane L A Chapgier

    PLoS ONE, Vol 11, Iss 8, p e

    2016  Volume 0161096

    Abstract: Chromatin remodelling is essential for cardiac development. Interestingly, the role of histone chaperones has not been investigated in this regard. HIRA is a member of the HUCA (HIRA/UBN1/CABIN1/ASF1a) complex that deposits the variant histone H3.3 on ... ...

    Abstract Chromatin remodelling is essential for cardiac development. Interestingly, the role of histone chaperones has not been investigated in this regard. HIRA is a member of the HUCA (HIRA/UBN1/CABIN1/ASF1a) complex that deposits the variant histone H3.3 on chromatin independently of replication. Lack of HIRA has general effects on chromatin and gene expression dynamics in embryonic stem cells and mouse oocytes. Here we describe the conditional ablation of Hira in the cardiogenic mesoderm of mice. We observed surface oedema, ventricular and atrial septal defects and embryonic lethality. We identified dysregulation of a subset of cardiac genes, notably upregulation of troponins Tnni2 and Tnnt3, involved in cardiac contractility and decreased expression of Epha3, a gene necessary for the fusion of the muscular ventricular septum and the atrioventricular cushions. We found that HIRA binds GAGA rich DNA loci in the embryonic heart, and in particular a previously described enhancer of Tnni2/Tnnt3 (TTe) bound by the transcription factor NKX2.5. HIRA-dependent H3.3 enrichment was observed at the TTe in embryonic stem cells (ESC) differentiated toward cardiomyocytes in vitro. Thus, we show here that HIRA has locus-specific effects on gene expression and that histone chaperone activity is vital for normal heart development, impinging on pathways regulated by an established cardiac transcription factor.
    Keywords Medicine ; R ; Science ; Q
    Subject code 570
    Language English
    Publishing date 2016-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Spatiotemporal dynamics and heterogeneity of renal lymphatics in mammalian development and cystic kidney disease

    Daniyal J Jafree / Dale Moulding / Maria Kolatsi-Joannou / Nuria Perretta Tejedor / Karen L Price / Natalie J Milmoe / Claire L Walsh / Rosa Maria Correra / Paul JD Winyard / Peter C Harris / Christiana Ruhrberg / Simon Walker-Samuel / Paul R Riley / Adrian S Woolf / Peter J Scambler / David A Long

    eLife, Vol

    2019  Volume 8

    Abstract: Heterogeneity of lymphatic vessels during embryogenesis is critical for organ-specific lymphatic function. Little is known about lymphatics in the developing kidney, despite their established roles in pathology of the mature organ. We performed three- ... ...

    Abstract Heterogeneity of lymphatic vessels during embryogenesis is critical for organ-specific lymphatic function. Little is known about lymphatics in the developing kidney, despite their established roles in pathology of the mature organ. We performed three-dimensional imaging to characterize lymphatic vessel formation in the mammalian embryonic kidney at single-cell resolution. In mouse, we visually and quantitatively assessed the development of kidney lymphatic vessels, remodeling from a ring-like anastomosis under the nascent renal pelvis; a site of VEGF-C expression, to form a patent vascular plexus. We identified a heterogenous population of lymphatic endothelial cell clusters in mouse and human embryonic kidneys. Exogenous VEGF-C expanded the lymphatic population in explanted mouse embryonic kidneys. Finally, we characterized complex kidney lymphatic abnormalities in a genetic mouse model of polycystic kidney disease. Our study provides novel insights into the development of kidney lymphatic vasculature; a system which likely has fundamental roles in renal development, physiology and disease.
    Keywords kidney ; lymphatics ; vessels ; development ; kidney disease ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
    Subject code 616
    Language English
    Publishing date 2019-12-01T00:00:00Z
    Publisher eLife Sciences Publications Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: In amnio MRI of mouse embryos.

    Thomas A Roberts / Francesca C Norris / Helen Carnaghan / Dawn Savery / Jack A Wells / Bernard Siow / Peter J Scambler / Agostino Pierro / Paolo De Coppi / Simon Eaton / Mark F Lythgoe

    PLoS ONE, Vol 9, Iss 10, p e

    2014  Volume 109143

    Abstract: Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is ... ...

    Abstract Mouse embryo imaging is conventionally carried out on ex vivo embryos excised from the amniotic sac, omitting vital structures and abnormalities external to the body. Here, we present an in amnio MR imaging methodology in which the mouse embryo is retained in the amniotic sac and demonstrate how important embryonic structures can be visualised in 3D with high spatial resolution (100 µm/px). To illustrate the utility of in amnio imaging, we subsequently apply the technique to examine abnormal mouse embryos with abdominal wall defects. Mouse embryos at E17.5 were imaged and compared, including three normal phenotype embryos, an abnormal embryo with a clear exomphalos defect, and one with a suspected gastroschisis phenotype. Embryos were excised from the mother ensuring the amnion remained intact and stereo microscopy was performed. Embryos were next embedded in agarose for 3D, high resolution MRI on a 9.4T scanner. Identification of the abnormal embryo phenotypes was not possible using stereo microscopy or conventional ex vivo MRI. Using in amnio MRI, we determined that the abnormal embryos had an exomphalos phenotype with varying severities. In amnio MRI is ideally suited to investigate the complex relationship between embryo and amnion, together with screening for other abnormalities located outside of the mouse embryo, providing a valuable complement to histology and existing imaging methods available to the phenotyping community.
    Keywords Medicine ; R ; Science ; Q
    Subject code 610
    Language English
    Publishing date 2014-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Correction

    Jennifer C. Fuchs / Fhatarah A. Zinnamon / Ruth R. Taylor / Sarah Ivins / Peter J. Scambler / Andrew Forge / Abigail S. Tucker / Jennifer F. Linden

    PLoS ONE, Vol 9, Iss

    Hearing Loss in a Mouse Model of 22q11.2 Deletion Syndrome

    2014  Volume 1

    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2014-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Correction

    Jennifer C. Fuchs / Fhatarah A. Zinnamon / Ruth R. Taylor / Sarah Ivins / Peter J. Scambler / Andrew Forge / Abigail S. Tucker / Jennifer F. Linden

    PLoS ONE, Vol 9, Iss

    Hearing Loss in a Mouse Model of 22q11.2 Deletion Syndrome.

    2014  Volume 1

    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2014-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Deregulated FGF and homeotic gene expression underlies cerebellar vermis hypoplasia in CHARGE syndrome

    Tian Yu / Linda C Meiners / Katrin Danielsen / Monica TY Wong / Timothy Bowler / Danny Reinberg / Peter J Scambler / Conny MA van Ravenswaaij-Arts / M Albert Basson

    eLife, Vol

    2013  Volume 2

    Abstract: Mutations in CHD7 are the major cause of CHARGE syndrome, an autosomal dominant disorder with an estimated prevalence of 1/15,000. We have little understanding of the disruptions in the developmental programme that underpin brain defects associated with ... ...

    Abstract Mutations in CHD7 are the major cause of CHARGE syndrome, an autosomal dominant disorder with an estimated prevalence of 1/15,000. We have little understanding of the disruptions in the developmental programme that underpin brain defects associated with this syndrome. Using mouse models, we show that Chd7 haploinsufficiency results in reduced Fgf8 expression in the isthmus organiser (IsO), an embryonic signalling centre that directs early cerebellar development. Consistent with this observation, Chd7 and Fgf8 loss-of-function alleles interact during cerebellar development. CHD7 associates with Otx2 and Gbx2 regulatory elements and altered expression of these homeobox genes implicates CHD7 in the maintenance of cerebellar identity during embryogenesis. Finally, we report cerebellar vermis hypoplasia in 35% of CHARGE syndrome patients with a proven CHD7 mutation. These observations provide key insights into the molecular aetiology of cerebellar defects in CHARGE syndrome and link reduced FGF signalling to cerebellar vermis hypoplasia in a human syndrome.
    Keywords cerebellum ; CHARGE syndrome ; CHD7 ; FGF8 ; OTX2 ; GBX2 ; Medicine ; R ; Science ; Q ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2013-12-01T00:00:00Z
    Publisher eLife Sciences Publications Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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