Donal MacGrogan1, Gaetano D'Amato1, Stanislao Travisano1, Beatriz Martinez-Poveda1, Guillermo Luxán1, Gonzalo Del Monte-Nieto1, Tania Papoutsi1, Mauro Sbroggio1, Vanesa Bou1, Pablo Gomez-Del Arco1, Manuel Jose Gómez1, Bin Zhou1, Juan Miguel Redondo1, Luis J Jiménez-Borreguero1, José Luis de la Pompa2. 1. From the Intercellular Signaling in Cardiovascular Development and Disease Laboratory (D.M., G.D., S.T., B.M.-P., G.L., G.d.M.-N., T.P., M.S., V.B., J.L.d.l.P.), Regulation of Gene Expression in Vascular Endothelium Laboratory (P.G.-d. A., J.M.R.), Bioinformatics Unit (M.J.G.), and Cardiovascular Imaging Laboratory (L.J.J.-B.), Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain (P.G.-d. A.); Department of Genetics, Pediatrics, and Medicine, Albert Einstein College of Medicine, New York, NY (B.Z.); and Instituto de Investigación Sanitaria Hospital, Universitario La Princesa, Madrid, Spain (L.J.J.-B.). 2. From the Intercellular Signaling in Cardiovascular Development and Disease Laboratory (D.M., G.D., S.T., B.M.-P., G.L., G.d.M.-N., T.P., M.S., V.B., J.L.d.l.P.), Regulation of Gene Expression in Vascular Endothelium Laboratory (P.G.-d. A., J.M.R.), Bioinformatics Unit (M.J.G.), and Cardiovascular Imaging Laboratory (L.J.J.-B.), Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain (P.G.-d. A.); Department of Genetics, Pediatrics, and Medicine, Albert Einstein College of Medicine, New York, NY (B.Z.); and Instituto de Investigación Sanitaria Hospital, Universitario La Princesa, Madrid, Spain (L.J.J.-B.). jlpompa@cnic.es.
Abstract
RATIONALE: The Notch signaling pathway is crucial for primitive cardiac valve formation by epithelial-mesenchymal transition, and NOTCH1 mutations cause bicuspid aortic valve; however, the temporal requirement for the various Notch ligands and receptors during valve ontogeny is poorly understood. OBJECTIVE: The aim of this study is to determine the functional specificity of Notch in valve development. METHODS AND RESULTS: Using cardiac-specific conditional targeted mutant mice, we find that endothelial/endocardial deletion of Mib1-Dll4-Notch1 signaling, possibly favored by Manic-Fringe, is specifically required for cardiac epithelial-mesenchymal transition. Mice lacking endocardial Jag1, Notch1, or RBPJ displayed enlarged valve cusps, bicuspid aortic valve, and septal defects, indicating that endocardial Jag1 to Notch1 signaling is required for post-epithelial-mesenchymal transition valvulogenesis. Valve dysmorphology was associated with increased mesenchyme proliferation, indicating that Jag1-Notch1 signaling restricts mesenchyme cell proliferation non-cell autonomously. Gene profiling revealed upregulated Bmp signaling in Jag1-mutant valves, providing a molecular basis for the hyperproliferative phenotype. Significantly, the negative regulator of mesenchyme proliferation, Hbegf, was markedly reduced in Jag1-mutant valves. Hbegf expression in embryonic endocardial cells could be readily activated through a RBPJ-binding site, identifying Hbegf as an endocardial Notch target. Accordingly, addition of soluble heparin-binding EGF-like growth factor to Jag1-mutant outflow tract explant cultures rescued the hyperproliferative phenotype. CONCLUSIONS: During cardiac valve formation, Dll4-Notch1 signaling leads to epithelial-mesenchymal transition and cushion formation. Jag1-Notch1 signaling subsequently restrains Bmp-mediated valve mesenchyme proliferation by sustaining Hbegf-EGF receptor signaling. Our studies identify a mechanism of signaling cross talk during valve morphogenesis involved in the origin of congenital heart defects associated with reduced NOTCH function.
RATIONALE: The Notch signaling pathway is crucial for primitive cardiac valve formation by epithelial-mesenchymal transition, and NOTCH1 mutations cause bicuspid aortic valve; however, the temporal requirement for the various Notch ligands and receptors during valve ontogeny is poorly understood. OBJECTIVE: The aim of this study is to determine the functional specificity of Notch in valve development. METHODS AND RESULTS: Using cardiac-specific conditional targeted mutant mice, we find that endothelial/endocardial deletion of Mib1-Dll4-Notch1 signaling, possibly favored by Manic-Fringe, is specifically required for cardiac epithelial-mesenchymal transition. Mice lacking endocardial Jag1, Notch1, or RBPJ displayed enlarged valve cusps, bicuspid aortic valve, and septal defects, indicating that endocardial Jag1 to Notch1 signaling is required for post-epithelial-mesenchymal transition valvulogenesis. Valve dysmorphology was associated with increased mesenchyme proliferation, indicating that Jag1-Notch1 signaling restricts mesenchyme cell proliferation non-cell autonomously. Gene profiling revealed upregulated Bmp signaling in Jag1-mutant valves, providing a molecular basis for the hyperproliferative phenotype. Significantly, the negative regulator of mesenchyme proliferation, Hbegf, was markedly reduced in Jag1-mutant valves. Hbegf expression in embryonic endocardial cells could be readily activated through a RBPJ-binding site, identifying Hbegf as an endocardial Notch target. Accordingly, addition of soluble heparin-binding EGF-like growth factor to Jag1-mutant outflow tract explant cultures rescued the hyperproliferative phenotype. CONCLUSIONS: During cardiac valve formation, Dll4-Notch1 signaling leads to epithelial-mesenchymal transition and cushion formation. Jag1-Notch1 signaling subsequently restrains Bmp-mediated valve mesenchyme proliferation by sustaining Hbegf-EGF receptor signaling. Our studies identify a mechanism of signaling cross talk during valve morphogenesis involved in the origin of congenital heart defects associated with reduced NOTCH function.
Authors: Gregory Farber; Matthew M Parks; Nicole Lustgarten Guahmich; Yi Zhang; Sébastien Monette; Scott C Blanchard; Annarita Di Lorenzo; Carl P Blobel Journal: Angiogenesis Date: 2018-11-16 Impact factor: 9.596
Authors: Jason C Kovacic; Stefanie Dimmeler; Richard P Harvey; Toren Finkel; Elena Aikawa; Guido Krenning; Andrew H Baker Journal: J Am Coll Cardiol Date: 2019-01-22 Impact factor: 24.094
Authors: Donna J Page; Matthieu J Miossec; Simon G Williams; Richard M Monaghan; Elisavet Fotiou; Heather J Cordell; Louise Sutcliffe; Ana Topf; Mathieu Bourgey; Guillaume Bourque; Robert Eveleigh; Sally L Dunwoodie; David S Winlaw; Shoumo Bhattacharya; Jeroen Breckpot; Koenraad Devriendt; Marc Gewillig; J David Brook; Kerry J Setchfield; Frances A Bu'Lock; John O'Sullivan; Graham Stuart; Connie R Bezzina; Barbara J M Mulder; Alex V Postma; James R Bentham; Martin Baron; Sanjeev S Bhaskar; Graeme C Black; William G Newman; Kathryn E Hentges; G Mark Lathrop; Mauro Santibanez-Koref; Bernard D Keavney Journal: Circ Res Date: 2019-02-15 Impact factor: 17.367