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Luo JY, Zhang Y, Wang L, Huang Y. Regulators and effectors of bone morphogenetic protein signalling in the cardiovascular system. J Physiol 2015; 593:2995-3011. [PMID: 25952563 DOI: 10.1113/jp270207] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/27/2015] [Indexed: 12/22/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) play key roles in the regulation of cell proliferation, differentiation and apoptosis in various tissues and organs, including the cardiovascular system. BMPs signal through both Smad-dependent and -independent cascades to exert a wide spectrum of biological activities. Cardiovascular disorders such as abnormal angiogenesis, atherosclerosis, pulmonary hypertension and cardiac hypertrophy have been linked to aberrant BMP signalling. To correct the dysregulated BMP signalling in cardiovascular pathogenesis, it is essential to get a better understanding of how the regulators and effectors of BMP signalling control cardiovascular function and how the dysregulated BMP signalling contributes to cardiovascular dysfunction. We hence highlight several key regulators of BMP signalling such as extracellular regulators of ligands, mechanical forces, microRNAs and small molecule drugs as well as typical BMP effectors like direct downstream target genes, mitogen-activated protein kinases, reactive oxygen species and microRNAs. The insights into these molecular processes will help target both the regulators and important effectors to reverse BMP-associated cardiovascular pathogenesis.
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Affiliation(s)
- Jiang-Yun Luo
- Shenzhen Research Institute, Institute of Vascular Medicine, and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yang Zhang
- Shenzhen Research Institute, Institute of Vascular Medicine, and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong SAR, China.,Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard University, Boston, MA, USA
| | - Li Wang
- Shenzhen Research Institute, Institute of Vascular Medicine, and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yu Huang
- Shenzhen Research Institute, Institute of Vascular Medicine, and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong SAR, China
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202
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Marks-Bluth J, Khanna A, Chandrakanthan V, Thoms J, Bee T, Eich C, Kang YC, Knezevic K, Qiao Q, Fitch S, Oxburgh L, Ottersbach K, Dzierzak E, de Bruijn MFTR, Pimanda JE. SMAD1 and SMAD5 Expression Is Coordinately Regulated by FLI1 and GATA2 during Endothelial Development. Mol Cell Biol 2015; 35:2165-72. [PMID: 25870111 PMCID: PMC4438244 DOI: 10.1128/mcb.00239-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/01/2015] [Accepted: 04/03/2015] [Indexed: 01/02/2023] Open
Abstract
The bone morphogenetic protein (BMP)/SMAD signaling pathway is a critical regulator of angiogenic sprouting and is involved in vascular development in the embryo. SMAD1 and SMAD5, the core mediators of BMP signaling, are vital for this activity, yet little is known about their transcriptional regulation in endothelial cells. Here, we have integrated multispecies sequence conservation, tissue-specific chromatin, in vitro reporter assay, and in vivo transgenic data to identify and validate Smad1+63 and the Smad5 promoter as tissue-specific cis-regulatory elements that are active in the developing endothelium. The activity of these elements in the endothelium was dependent on highly conserved ETS, GATA, and E-box motifs, and chromatin immunoprecipitation showed high levels of enrichment of FLI1, GATA2, and SCL at these sites in endothelial cell lines and E11 dorsal aortas in vivo. Knockdown of FLI1 and GATA2 but not SCL reduced the expression of SMAD1 and SMAD5 in endothelial cells in vitro. In contrast, CD31(+) cKit(-) endothelial cells harvested from embryonic day 9 (E9) aorta-gonad-mesonephros (AGM) regions of GATA2 null embryos showed reduced Smad1 but not Smad5 transcript levels. This is suggestive of a degree of in vivo selection where, in the case of reduced SMAD1 levels, endothelial cells with more robust SMAD5 expression have a selective advantage.
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Affiliation(s)
- Jonathon Marks-Bluth
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Anchit Khanna
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Vashe Chandrakanthan
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Julie Thoms
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Thomas Bee
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Christina Eich
- Erasmus MC Stem Cell Institute, Department of Cell Biology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Young Chan Kang
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Kathy Knezevic
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Qiao Qiao
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia
| | - Simon Fitch
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Leif Oxburgh
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA
| | - Katrin Ottersbach
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Elaine Dzierzak
- Erasmus MC Stem Cell Institute, Department of Cell Biology, Erasmus University Medical Center, Rotterdam, Netherlands The Queen's Medical Research Institute, College of Medicine and Veterinary Medicine, Edinburgh, United Kingdom
| | - Marella F T R de Bruijn
- The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - John E Pimanda
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, The University of New South Wales, Sydney, NSW, Australia Department of Haematology, Prince of Wales Hospital, Sydney, NSW, Australia
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203
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Mahadevaiah S, Robinson KG, Kharkar PM, Kiick KL, Akins RE. Decreasing matrix modulus of PEG hydrogels induces a vascular phenotype in human cord blood stem cells. Biomaterials 2015; 62:24-34. [PMID: 26016692 DOI: 10.1016/j.biomaterials.2015.05.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 05/04/2015] [Accepted: 05/14/2015] [Indexed: 01/12/2023]
Abstract
Adult and congenital cardiovascular diseases are significant health problems that are often managed using surgery. Bypass grafting is a principal therapy, but grafts fail at high rates due to hyperplasia, fibrosis, and atherosclerosis. Biocompatible, cellularized materials that attenuate these complications and encourage healthy microvascularization could reduce graft failure, but an improved understanding of biomaterial effects on human stem cells is needed to reach clinical utility. Our group investigates stem-cell-loaded biomaterials for placement along the adventitia of at-risk vessels and grafts. Here, the effects of substrate modulus on human CD34+ stem cells from umbilical cord blood were evaluated. Cells were isolated by immunomagnetic separation and encapsulated in 3, 4, and 6 weight% PEG hydrogels containing 0.032% gelatin and 0.0044% fibronectin. Gels reached moduli of 0.34, 4.5, and 9.1 kPa. Cell viability approached 100%. Cell morphologies appeared similar across gels, but proliferation was significantly lower in 6 wt% gels. Expression profiling using stem cell signaling arrays indicated enhanced self-renewal and differentiation into vascular endothelium among cells in the lower weight percent gels. Thus, modulus was associated with cell proliferation and function. Gels with moduli in the low kilopascal range may be useful in stimulating cell engraftment and microvascularization of graft adventitia.
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Affiliation(s)
- Shruthi Mahadevaiah
- Nemours - Alfred I. duPont Hospital for Children, Department of Biomedical Research, 1600 Rockland Road, Wilmington, DE 19803, United States; Nemours - Alfred I. duPont Hospital for Children, Critical Care Department, 1600 Rockland Road, Wilmington, DE 19803, United States
| | - Karyn G Robinson
- Nemours - Alfred I. duPont Hospital for Children, Department of Biomedical Research, 1600 Rockland Road, Wilmington, DE 19803, United States
| | - Prathamesh M Kharkar
- Department of Materials Science and Engineering, University of Delaware, 201 Du Pont Hall, Newark, DE 19716, United States
| | - Kristi L Kiick
- Department of Materials Science and Engineering, University of Delaware, 201 Du Pont Hall, Newark, DE 19716, United States
| | - Robert E Akins
- Nemours - Alfred I. duPont Hospital for Children, Department of Biomedical Research, 1600 Rockland Road, Wilmington, DE 19803, United States.
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204
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Klose R, Berger C, Moll I, Adam MG, Schwarz F, Mohr K, Augustin HG, Fischer A. Soluble Notch ligand and receptor peptides act antagonistically during angiogenesis. Cardiovasc Res 2015; 107:153-63. [PMID: 25975260 DOI: 10.1093/cvr/cvv151] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 05/07/2015] [Indexed: 01/06/2023] Open
Abstract
AIMS Notch signalling is essential for blood vessel formation. During angiogenesis, the Notch ligand DLL4 on the leading tip cell activates Notch receptors on the adjacent stalk cells. DLL4-Notch signalling is impaired by the Notch ligand JAG1 in endothelial cells. The Delta/Serrate/Lag2 (DSL) domain of the Notch ligands binds to the EGF-like repeats 11-13 of the Notch receptor. This study aimed to elucidate how soluble proteins containing these short domains interfere with Notch signalling during angiogenesis. METHODS AND RESULTS Adenoviral vectors were generated to express the DSL domains of DLL1, DLL4, JAG1, and the Notch1 EGF-like repeats 11-13 fused to immunoglobulin-G heavy chain. These soluble ligand peptides inhibited Notch signalling in endothelial cells and this caused hyperbranching in cellular angiogenesis assays and in the neonatal mouse retina. The soluble Notch receptor peptides bound stronger to JAG1 than DLL4 ligands, resulting in increased signalling activity. This led to impaired tip cell formation and less vessel sprouting in the retina. CONCLUSION The minimal binding domains of Notch ligands are sufficient to interfere with Notch signalling. The corresponding soluble Notch1 EGF11-13 peptide binds stronger to inhibitory Notch ligands and thereby promotes Notch signalling in endothelial cells.
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Affiliation(s)
- Ralph Klose
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany
| | - Caroline Berger
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, Mannheim D-68167, Germany
| | - Iris Moll
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany
| | - M Gordian Adam
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, Mannheim D-68167, Germany
| | - Frank Schwarz
- Genomics and Proteomics Core Facilities, German Cancer Research Center, Heidelberg D-69120, Germany
| | - Kerstin Mohr
- Genomics and Proteomics Core Facilities, German Cancer Research Center, Heidelberg D-69120, Germany
| | - Hellmut G Augustin
- Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, Mannheim D-68167, Germany Vascular Oncology and Metastasis (A190), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany
| | - Andreas Fischer
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), Heidelberg D-69120, Germany Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, Mannheim D-68167, Germany Department of Medicine I and Clinical Chemistry, Heidelberg University, Heidelberg D-69120, Germany
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205
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Rochon ER, Wright DS, Schubert MM, Roman BL. Context-specific interactions between Notch and ALK1 cannot explain ALK1-associated arteriovenous malformations. Cardiovasc Res 2015; 107:143-52. [PMID: 25969392 DOI: 10.1093/cvr/cvv148] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 05/07/2015] [Indexed: 01/17/2023] Open
Abstract
AIMS Notch and activin receptor-like kinase 1 (ALK1) have been implicated in arterial specification, angiogenic tip/stalk cell differentiation, and development of arteriovenous malformations (AVMs), and ALK1 can cooperate with Notch to up-regulate expression of Notch target genes in cultured endothelial cells. These findings suggest that Notch and ALK1 might collaboratively program arterial identity and prevent AVMs. We therefore sought to investigate the interaction between Notch and Alk1 signalling in the developing vertebrate vasculature. METHODS AND RESULTS We modulated Notch and Alk1 activities in zebrafish embryos and examined effects on Notch target gene expression and vascular morphology. Although Alk1 is not necessary for expression of Notch target genes in arterial endothelium, loss of Notch signalling unmasks a role for Alk1 in supporting hey2 and ephrinb2a expression in the dorsal aorta. In contrast, Notch and Alk1 play opposing roles in hey2 expression in cranial arteries and dll4 expression in all arterial endothelium, with Notch inducing and Alk1 repressing these genes. Although alk1 loss increases expression of dll4, AVMs in alk1 mutants could neither be phenocopied by Notch activation nor rescued by Dll4/Notch inhibition. CONCLUSION Control of Notch targets in arterial endothelium is context-dependent, with gene-specific and region-specific requirements for Notch and Alk1. Alk1 is not required for arterial identity, and perturbations in Notch signalling cannot account for alk1 mutant-associated AVMs. These data suggest that AVMs associated with ALK1 mutation are not caused by defective arterial specification or altered Notch signalling.
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Affiliation(s)
- Elizabeth R Rochon
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Daniel S Wright
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Max M Schubert
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Beth L Roman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, 130 DeSoto St, Pittsburgh, PA 15261, USA
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206
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Rama N, Dubrac A, Mathivet T, Ní Chárthaigh RA, Genet G, Cristofaro B, Pibouin-Fragner L, Ma L, Eichmann A, Chédotal A. Slit2 signaling through Robo1 and Robo2 is required for retinal neovascularization. Nat Med 2015; 21:483-91. [PMID: 25894826 PMCID: PMC4819398 DOI: 10.1038/nm.3849] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/25/2015] [Indexed: 02/07/2023]
Abstract
Ocular neovascular diseases are a leading cause of blindness. Vascular endothelial growth factor (VEGF) blockade improves vision, but not all individuals respond to anti-VEGF treatment, making additional means to prevent neovascularization necessary. Slit-family proteins (Slits) are ligands of Roundabout (Robo) receptors that repel developing axons in the nervous system. Robo1 expression is altered in ocular neovascular diseases, and previous in vitro studies have reported both pro- and anti-angiogenic effects of Slits. However, genetic evidence supporting a role for Slits in ocular neovascularization is lacking. Here we generated conditional knockout mice deficient in various Slit and Robo proteins and found that Slit2 potently and selectively promoted angiogenesis via Robo1 and Robo2 in mouse postnatal retina and in a model of ocular neovascular disease. Mechanistically, Slit2 acting through Robo1 and Robo2 promoted the migration of endothelial cells. These receptors are required for both Slit2- and VEGF-induced Rac1 activation and lamellipodia formation. Thus, Slit2 blockade could potentially be used therapeutically to inhibit angiogenesis in individuals with ocular neovascular disease.
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Affiliation(s)
- Nicolas Rama
- 1] INSERM UMR S968, Institut de la Vision, Paris, France. [2] Université Pierre et Marie Curie, Sorbonne Universités, Paris, France. [3] UMR 7210, CNRS, Paris, France
| | - Alexandre Dubrac
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Thomas Mathivet
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, Paris, France
| | - Róisín-Ana Ní Chárthaigh
- 1] INSERM UMR S968, Institut de la Vision, Paris, France. [2] Université Pierre et Marie Curie, Sorbonne Universités, Paris, France. [3] UMR 7210, CNRS, Paris, France
| | - Gael Genet
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Brunella Cristofaro
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, Paris, France
| | | | - Le Ma
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Anne Eichmann
- 1] Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Center for Interdisciplinary Research in Biology (CIRB), Collège de France, Paris, France. [3] Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Alain Chédotal
- 1] INSERM UMR S968, Institut de la Vision, Paris, France. [2] Université Pierre et Marie Curie, Sorbonne Universités, Paris, France. [3] UMR 7210, CNRS, Paris, France
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207
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Brand OJ, Somanath S, Moermans C, Yanagisawa H, Hashimoto M, Cambier S, Markovics J, Bondesson AJ, Hill A, Jablons D, Wolters P, Lou J, Marks JD, Baron JL, Nishimura SL. Transforming Growth Factor-β and Interleukin-1β Signaling Pathways Converge on the Chemokine CCL20 Promoter. J Biol Chem 2015; 290:14717-28. [PMID: 25918170 DOI: 10.1074/jbc.m114.630368] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Indexed: 12/27/2022] Open
Abstract
CCL20 is the only chemokine ligand for the chemokine receptor CCR6, which is expressed by the critical antigen presenting cells, dendritic cells. Increased expression of CCL20 is likely involved in the increased recruitment of dendritic cells observed in fibroinflammatory diseases such as chronic obstructive pulmonary disease (COPD). CCL20 expression is increased by the proinflammatory cytokine IL-1β. We have determined that IL-1β-dependent CCL20 expression is also dependent on the multifunctional cytokine TGF-β. TGF-β is expressed in a latent form that must be activated to function, and activation is achieved through binding to the integrin αvβ8 (itgb8). Here we confirm correlative increases in αvβ8 and IL-1β with CCL20 protein in lung parenchymal lysates of a large cohort of COPD patients. How IL-1β- and αvβ8-mediated TGF-β activation conspire to increase fibroblast CCL20 expression remains unknown, because these pathways have not been shown to directly interact. We evaluate the 5'-flanking region of CCL20 to determine that IL-1β-driven CCL20 expression is dependent on αvβ8-mediated activation of TGF-β. We identify a TGF-β-responsive element (i.e. SMAD) located on an upstream enhancer of the human CCL20 promoter required for efficient IL-1β-dependent CCL20 expression. By chromatin immunoprecipitation, this upstream enhancer complexes with the p50 subunit of NF-κB on a NF-κB-binding element close to the transcriptional start site of CCL20. These interactions are confirmed by electromobility shift assays in nuclear extracts from human lung fibroblasts. These data define a mechanism by which αvβ8-dependent activation of TGF-β regulates IL-1β-dependent CCL20 expression in COPD.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Arthur Hill
- Surgery, University of California, San Francisco, California 94110
| | - David Jablons
- Surgery, University of California, San Francisco, California 94110
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208
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Young K, Tweedie E, Conley B, Ames J, FitzSimons M, Brooks P, Liaw L, Vary CPH. BMP9 Crosstalk with the Hippo Pathway Regulates Endothelial Cell Matricellular and Chemokine Responses. PLoS One 2015; 10:e0122892. [PMID: 25909848 PMCID: PMC4409298 DOI: 10.1371/journal.pone.0122892] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/24/2015] [Indexed: 12/26/2022] Open
Abstract
Endoglin is a type III TGFβ auxiliary receptor that is upregulated in endothelial cells during angiogenesis and, when mutated in humans, results in the vascular disease hereditary hemorrhagic telangiectasia (HHT). Though endoglin has been implicated in cell adhesion, the underlying molecular mechanisms are still poorly understood. Here we show endoglin expression in endothelial cells regulates subcellular localization of zyxin in focal adhesions in response to BMP9. RNA knockdown of endoglin resulted in mislocalization of zyxin and altered formation of focal adhesions. The mechanotransduction role of focal adhesions and their ability to transmit regulatory signals through binding of the extracellular matrix are altered by endoglin deficiency. BMP/TGFβ transcription factors, SMADs, and zyxin have recently been implicated in a newly emerging signaling cascade, the Hippo pathway. The Hippo transcription coactivator, YAP1 (yes-associated protein 1), has been suggested to play a crucial role in mechanotransduction and cell-cell contact. Identification of BMP9-dependent nuclear localization of YAP1 in response to endoglin expression suggests a mechanism of crosstalk between the two pathways. Suppression of endoglin and YAP1 alters BMP9-dependent expression of YAP1 target genes CCN1 (cysteine-rich 61, CYR61) and CCN2 (connective tissue growth factor, CTGF) as well as the chemokine CCL2 (monocyte chemotactic protein 1, MCP-1). These results suggest a coordinate effect of endoglin deficiency on cell matrix remodeling and local inflammatory responses. Identification of a direct link between the Hippo pathway and endoglin may reveal novel mechanisms in the etiology of HHT.
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Affiliation(s)
- Kira Young
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Eric Tweedie
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
| | - Barbara Conley
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
| | - Jacquelyn Ames
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - MaryLynn FitzSimons
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Peter Brooks
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Lucy Liaw
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
| | - Calvin P. H. Vary
- Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine 04074, United States of America
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, United States of America
- * E-mail:
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209
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Davare MA, Tognon CE. Detecting and targetting oncogenic fusion proteins in the genomic era. Biol Cell 2015; 107:111-29. [PMID: 25631473 DOI: 10.1111/boc.201400096] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 01/23/2015] [Indexed: 12/15/2022]
Abstract
The advent of widespread cancer genome sequencing has accelerated our understanding of the molecular aberrations underlying malignant disease at an unprecedented rate. Coupling the large number of bioinformatic methods developed to locate genomic breakpoints with increased sequence read length and a deeper understanding of coding region function has enabled rapid identification of novel actionable oncogenic fusion genes. Using examples of kinase fusions found in liquid and solid tumours, this review highlights major concepts that have arisen in our understanding of cancer pathogenesis through the study of fusion proteins. We provide an overview of recently developed methods to identify potential fusion proteins from next-generation sequencing data, describe the validation of their oncogenic potential and discuss the role of targetted therapies in treating cancers driven by fusion oncoproteins.
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Affiliation(s)
- Monika A Davare
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR, 97239, U.S.A; Department of Pediatrics, Oregon Health & Science University, Portland, OR, 97239, U.S.A
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210
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Kerr G, Sheldon H, Chaikuad A, Alfano I, von Delft F, Bullock AN, Harris AL. A small molecule targeting ALK1 prevents Notch cooperativity and inhibits functional angiogenesis. Angiogenesis 2015; 18:209-17. [PMID: 25557927 PMCID: PMC4363482 DOI: 10.1007/s10456-014-9457-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 12/22/2014] [Indexed: 10/26/2022]
Abstract
Activin receptor-like kinase 1 (ALK1, encoded by the gene ACVRL1) is a type I BMP/TGF-β receptor that mediates signalling in endothelial cells via phosphorylation of SMAD1/5/8. During angiogenesis, sprouting endothelial cells specialise into tip cells and stalk cells. ALK1 synergises with Notch in stalk cells to induce expression of the Notch targets HEY1 and HEY2 and thereby represses tip cell formation and angiogenic sprouting. The ALK1-Fc soluble protein fusion has entered clinic trials as a therapeutic strategy to sequester the high-affinity extracellular ligand BMP9. Here, we determined the crystal structure of the ALK1 intracellular kinase domain and explored the effects of a small molecule kinase inhibitor K02288 on angiogenesis. K02288 inhibited BMP9-induced phosphorylation of SMAD1/5/8 in human umbilical vein endothelial cells to reduce both the SMAD and the Notch-dependent transcriptional responses. In endothelial sprouting assays, K02288 treatment induced a hypersprouting phenotype reminiscent of Notch inhibition. Furthermore, K02288 caused dysfunctional vessel formation in a chick chorioallantoic membrane assay of angiogenesis. Such activity may be advantageous for small molecule inhibitors currently in preclinical development for specific BMP gain of function conditions, including diffuse intrinsic pontine glioma and fibrodysplasia ossificans progressiva, as well as more generally for other applications in tumour biology.
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Affiliation(s)
- Georgina Kerr
- Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford, OX3 7DQ UK
| | - Helen Sheldon
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford, OX3 9DS UK
| | - Apirat Chaikuad
- Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford, OX3 7DQ UK
| | - Ivan Alfano
- Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford, OX3 7DQ UK
| | - Frank von Delft
- Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford, OX3 7DQ UK
| | - Alex N. Bullock
- Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford, OX3 7DQ UK
| | - Adrian L. Harris
- Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Headington, Oxford, OX3 9DS UK
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211
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Wöltje K, Jabs M, Fischer A. Serum induces transcription of Hey1 and Hey2 genes by Alk1 but not Notch signaling in endothelial cells. PLoS One 2015; 10:e0120547. [PMID: 25799559 PMCID: PMC4370690 DOI: 10.1371/journal.pone.0120547] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/23/2015] [Indexed: 01/10/2023] Open
Abstract
The transcriptional repressors Hey1 and Hey2 are primary target genes of Notch signaling in the cardiovascular system and induction of Hey gene expression is often interpreted as activation of Notch signaling. Here we report that treatment of primary human endothelial cells with serum or fresh growth medium led to a strong wave of Hey1 and Hey2 transcription lasting for approximately three hours. Transcription of other Notch target genes (Hes1, Hes5, ephrinB2, Dll4) was however not induced by serum in endothelial cells. Gamma secretase inhibition or expression of dominant-negative MAML1 did not prevent the induction of Hey genes indicating that canonical Notch signaling is dispensable. Pretreatment with soluble BMP receptor Alk1, but not Alk3, abolished Hey gene induction by serum. Consequently, the Alk1 ligand BMP9 stimulated Hey gene induction in endothelial cells. Several other cell types however did not show such a strong BMP signaling and consequently only a very mild induction of Hey genes. Taken together, the experiments revealed that bone morphogenic proteins within the serum of cell culture medium are potent inducers of endothelial Hey1 and Hey2 gene expression within the first few hours after medium change.
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Affiliation(s)
- Kerstin Wöltje
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), D-69120, Heidelberg, Germany
| | - Markus Jabs
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), D-69120, Heidelberg, Germany
| | - Andreas Fischer
- Vascular Signaling and Cancer (A270), German Cancer Research Center (DKFZ-ZMBH Alliance), D-69120, Heidelberg, Germany
- Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, D-68167, Mannheim, Germany
- Department of Medicine I and Clinical Chemistry, Heidelberg University, D-69120, Heidelberg, Germany
- * E-mail:
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212
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Abstract
Blood and lymphatic vessels deliver oxygen and nutrients, remove waste and CO2, and regulate interstitial pressure in tissues and organs. These vessels begin life early in embryogenesis using transcription factors and signaling pathways that regulate differentiation, morphogenesis, and proliferation. Here we describe how these vessels develop in the mouse embryo, and the signals that are important to their development.
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Affiliation(s)
- Victoria L Bautch
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Kathleen M Caron
- McAllister Heart Institute, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 Department of Cell and Molecular Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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213
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Tual-Chalot S, Oh SP, Arthur HM. Mouse models of hereditary hemorrhagic telangiectasia: recent advances and future challenges. Front Genet 2015; 6:25. [PMID: 25741358 PMCID: PMC4332371 DOI: 10.3389/fgene.2015.00025] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 01/19/2015] [Indexed: 12/15/2022] Open
Abstract
Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterized by a multi-systemic vascular dysplasia and hemorrhage. The precise factors leading to these vascular malformations are not yet understood and robust animal models of HHT are essential to gain a detailed understanding of the molecular and cellular events that lead to clinical symptoms, as well as to test new therapeutic modalities. Most cases of HHT are caused by mutations in either endoglin (ENG) or activin receptor-like kinase 1 (ACVRL1, also known as ALK1). Both genes are associated with TGFβ/BMP signaling, and loss of function mutations in the co-receptor ENG are causal in HHT1, while HHT2 is associated with mutations in the signaling receptor ACVRL1. Significant advances in mouse genetics have provided powerful ways to study the function of Eng and Acvrl1 in vivo, and to generate mouse models of HHT disease. Mice that are null for either Acvrl1 or Eng genes show embryonic lethality due to major defects in angiogenesis and heart development. However mice that are heterozygous for mutations in either of these genes develop to adulthood with no effect on survival. Although these heterozygous mice exhibit selected vascular phenotypes relevant to the clinical pathology of HHT, the phenotypes are variable and generally quite mild. An alternative approach using conditional knockout mice allows us to study the effects of specific inactivation of either Eng or Acvrl1 at different times in development and in different cell types. These conditional knockout mice provide robust and reproducible models of arteriovenous malformations, and they are currently being used to unravel the causal factors in HHT pathologies. In this review, we will summarize the strengths and limitations of current mouse models of HHT, discuss how knowledge obtained from these studies has already informed clinical care and explore the potential of these models for developing improved treatments for HHT patients in the future.
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Affiliation(s)
| | - S Paul Oh
- Department of Physiology and Functional Genomics, University of Florida , Gainesville, FL, USA
| | - Helen M Arthur
- Institute of Genetic Medicine, Newcastle University , Newcastle, UK
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214
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Thalgott J, Dos-Santos-Luis D, Lebrin F. Pericytes as targets in hereditary hemorrhagic telangiectasia. Front Genet 2015; 6:37. [PMID: 25763012 PMCID: PMC4327729 DOI: 10.3389/fgene.2015.00037] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/26/2015] [Indexed: 12/04/2022] Open
Abstract
Defective paracrine Transforming Growth Factor-β (TGF-β) signaling between endothelial cells and the neighboring mural cells have been thought to lead to the development of vascular lesions that are characteristic of Hereditary Hemorrhagic Telangiectasia (HHT). This review highlights recent progress in our understanding of TGF-β signaling in mural cell recruitment and vessel stabilization and how perturbed TGF-β signaling might contribute to defective endothelial-mural cell interaction affecting vessel functionalities. Our recent findings have provided exciting insights into the role of thalidomide, a drug that reduces both the frequency and the duration of epistaxis in individuals with HHT by targeting mural cells. These advances provide opportunities for the development of new therapies for vascular malformations.
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Affiliation(s)
- Jérémy Thalgott
- INSERM, Center for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM U1050, Group Pathological Angiogenesis and Vessel Normalization, Collège de France Paris, France
| | - Damien Dos-Santos-Luis
- INSERM, Center for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM U1050, Group Pathological Angiogenesis and Vessel Normalization, Collège de France Paris, France
| | - Franck Lebrin
- INSERM, Center for Interdisciplinary Research in Biology, UMR CNRS 7241/INSERM U1050, Group Pathological Angiogenesis and Vessel Normalization, Collège de France Paris, France
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215
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Zhang K, Zhang YQ, Ai WB, Hu QT, Zhang QJ, Wan LY, Wang XL, Liu CB, Wu JF. Hes1, an important gene for activation of hepatic stellate cells, is regulated by Notch1 and TGF-β/BMP signaling. World J Gastroenterol 2015; 21:878-887. [PMID: 25624721 PMCID: PMC4299340 DOI: 10.3748/wjg.v21.i3.878] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 06/18/2014] [Accepted: 07/16/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To determine the role of Notch1 and Hes1 in regulating the activation of hepatic stellate cells (HSCs) and whether Hes1 is regulated by transforming growth factor (TGF)/bone morphogenetic protein (BMP) signaling.
METHODS: Immunofluorescence staining was used to detect the expression of desmin, glial fibrillary acidic protein and the myofibroblastic marker α-smooth muscle actin (α-SMA) after freshly isolated, normal rat HSCs had been activated in culture for different numbers of days (0, 1, 3, 7 and 10 d). The expression of α-SMA, collagen1α2 (COL1α2), Notch receptors (Notch1-4), and the Notch target genes Hes1 and Hey1 were analyzed by reverse transcriptase-polymerase chain reaction. Luciferase reporter assays and Western blot were used to study the regulation of α-SMA, COL1α1, COL1α2 and Hes1 by NICD1, Hes1, CA-ALK3, and CA-ALK5 in HSC-T6 cells. Moreover, the effects of inhibiting Hes1 function in HSC-T6 cells using a Hes1 decoy were also investigated.
RESULTS: The expression of Notch1 and Hes1 mRNAs was significantly down-regulated during the culture of freshly isolated HSCs. In HSC-T6 cells, Notch1 inhibited the promoter activities of α-SMA, COL1α1 and COL1α2. On the other hand, Hes1 enhanced the promoter activities of α-SMA and COL1α2, and this effect could be blocked by inhibiting Hes1 function with a Hes1 decoy. Furthermore, co-transfection of pcDNA3-CA-ALK3 (BMP signaling activin receptor-like kinase 3) and pcDNA3.1-NICD1 further increased the expression of Hes1 compared with transfection of either vector alone in HSC-T6 cells, while pcDNA3-CA-ALK5 (TGF-β signaling activin receptor-like kinase 5) reduced the effect of NICD1 on Hes1 expression.
CONCLUSION: Selective interruption of Hes1 or maintenance of Hes1 at a reasonable level decreases the promoter activities of α-SMA and COL1α2, and these conditions may provide an anti-fibrotic strategy against hepatic fibrosis.
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MESH Headings
- Actins/genetics
- Actins/metabolism
- Animals
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- Biomarkers/metabolism
- Bone Morphogenetic Protein Receptors, Type I/genetics
- Bone Morphogenetic Protein Receptors, Type I/metabolism
- Bone Morphogenetic Proteins/metabolism
- Cells, Cultured
- Collagen Type I/genetics
- Collagen Type I/metabolism
- Gene Expression Regulation
- Genes, Reporter
- Hepatic Stellate Cells/metabolism
- Hepatic Stellate Cells/pathology
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Liver Cirrhosis/genetics
- Liver Cirrhosis/metabolism
- Liver Cirrhosis/pathology
- Myofibroblasts/metabolism
- Myofibroblasts/pathology
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- RNA, Messenger/metabolism
- Rats
- Receptor, Notch1/genetics
- Receptor, Notch1/metabolism
- Receptor, Transforming Growth Factor-beta Type I
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Signal Transduction
- Time Factors
- Transcription Factor HES-1
- Transfection
- Transforming Growth Factor beta/metabolism
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216
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Moon EH, Kim YS, Seo J, Lee S, Lee YJ, Oh SP. Essential role for TMEM100 in vascular integrity but limited contributions to the pathogenesis of hereditary haemorrhagic telangiectasia. Cardiovasc Res 2014; 105:353-60. [PMID: 25538155 DOI: 10.1093/cvr/cvu260] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIMS TMEM100 was previously identified as a downstream target of activin receptor-like kinase 1 (ALK1; ACVRL1) signalling. Mutations on ALK1 cause hereditary haemorrhagic telangiectasia (HHT), a vascular disorder characterized by mucocutaneous telangiectases and visceral arteriovenous malformations (AVMs). The aims of this study are to investigate the in vivo role of TMEM100 at various developmental and adult stages and to determine the extent to which TMEM100 contributed to the development of AVMs as a key downstream effector of ALK1. METHODS AND RESULTS Blood vasculature in Tmem100-null embryos and inducible Tmem100-null neonatal and adult mice was examined. We found that TMEM100 deficiency resulted in cardiovascular defects at embryonic stage; dilated vessels, hyperbranching, and increased number of filopodia in the retinal vasculature at neonatal stage; and various vascular abnormalities, including internal haemorrhage, arteriovenous shunts, and weakening of vasculature with abnormal elastin layers at adult stage. However, arteriovenous shunts in adult mutant mice appeared to be underdeveloped without typical tortuosity of vessels associated with AVMs. We uncovered that the expression of genes encoding cell adhesion and extracellular matrix proteins was significantly affected in lungs of adult mutant mice. Especially Mfap4, which is associated with elastin fibre formation, was mostly down-regulated. CONCLUSION These results demonstrate that TMEM100 has essential functions for the maintenance of vascular integrity as well as the formation of blood vessels. Our results also indicate that down-regulation of Tmem100 is not the central mechanism of HHT pathogenesis, but it may contribute to the development of vascular pathology of HHT by weakening vascular integrity.
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Affiliation(s)
- Eun-Hye Moon
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea
| | - Yoo Sung Kim
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea
| | - Jiyoung Seo
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea
| | - Sabin Lee
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea
| | - Young Jae Lee
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea
| | - Suk Paul Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea Department of Physiology and Functional Genomics, College of Medicine, University of Florida, 1600 SW Archer Road, Room CG-20B, Gainesville, FL 32610, USA
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217
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Roman BL, Finegold DN. Genetic and Molecular Basis for Hereditary Hemorrhagic Telangiectasia. CURRENT GENETIC MEDICINE REPORTS 2014. [DOI: 10.1007/s40142-014-0061-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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218
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Wong A, Young B. The future is now: frontiers on display at Yale-NAVBO cardiovascular inflammation and remodeling symposium 2014. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2014; 87:593-9. [PMID: 25506292 PMCID: PMC4257044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Earlier this year, 200 researchers from across the globe gathered at the Omni New Haven Hotel at Yale University in New Haven, Connecticut, for 3 days of talks from 30 of the leading pioneers in modern cardiovascular medicine. From May 8 to 10, 2014, scientists discussed and dissected topics ranging from the clinical treatment of atherosclerosis to the molecular biology of leukocyte-endothelial cell interactions. With other sessions exploring vascular malformation and aneurysm, hypertension, the endothelial-mesenchymal transition (endo-MT), and the role of metabolism in cardiovascular disease, conference participants gained striking insights into rapid advances and ongoing challenges in the field of cardiovascular inflammation and remodeling.
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Affiliation(s)
- Albert Wong
- Department of Cell Biology, Yale School of Medicine, New Haven, Connecticut
| | - Bryan Young
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
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219
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Constitutively active Notch4 receptor elicits brain arteriovenous malformations through enlargement of capillary-like vessels. Proc Natl Acad Sci U S A 2014; 111:18007-12. [PMID: 25468970 DOI: 10.1073/pnas.1415316111] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Arteriovenous (AV) malformation (AVM) is a devastating condition characterized by focal lesions of enlarged, tangled vessels that shunt blood from arteries directly to veins. AVMs can form anywhere in the body and can cause debilitating ischemia and life-threatening hemorrhagic stroke. The mechanisms that underlie AVM formation remain poorly understood. Here, we examined the cellular and hemodynamic changes at the earliest stages of brain AVM formation by time-lapse two-photon imaging through cranial windows of mice expressing constitutively active Notch4 (Notch4*). AVMs arose from enlargement of preexisting microvessels with capillary diameter and blood flow and no smooth muscle cell coverage. AV shunting began promptly after Notch4* expression in endothelial cells (ECs), accompanied by increased individual EC areas, rather than increased EC number or proliferation. Alterations in Notch signaling in ECs of all vessels, but not arteries alone, affected AVM formation, suggesting that Notch functions in the microvasculature and/or veins to induce AVM. Increased Notch signaling interfered with the normal biological control of hemodynamics, permitting a positive feedback loop of increasing blood flow and vessel diameter and driving focal AVM growth from AV connections with higher blood velocity at the expense of adjacent AV connections with lower velocity. Endothelial expression of constitutively active Notch1 also led to brain AVMs in mice. Our data shed light on cellular and hemodynamic mechanisms underlying AVM pathogenesis elicited by increased Notch signaling in the endothelium.
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220
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Li Y, Fu S, Chen H, Feng Q, Gao Y, Xue H, Ge Z, Fang J, Xiao S. Inhibition of endothelial Slit2/Robo1 signaling by thalidomide restrains angiogenesis by blocking the PI3K/Akt pathway. Dig Dis Sci 2014; 59:2958-66. [PMID: 25326112 DOI: 10.1007/s10620-014-3257-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 06/16/2014] [Indexed: 12/09/2022]
Abstract
BACKGROUND Thalidomide is effective in the treatment of angiodysplasia. The mechanisms underlying its activity may be associated with inhibition of angiogenic factors. It was recently shown that Slit2/Robo1 signaling plays a role in angiogenesis. PURPOSE The aim of this study was to explore the expression and effects of Robo1 and Slit2 in angiodysplasia and to identify the possible therapeutic mechanisms of thalidomide. METHOD Slit2 and Robo1 expression were analyzed in tissue samples and human umbilical vein endothelial cells (HUVECs) treated with thalidomide using a combination of laboratory assays that were able to detect functional activity. RESULTS Slit2, Robo1 and vascular endothelial growth factor (VEGF) were strongly expressed in five angiodysplasia lesions out of seven cases, while expression was low in one out of seven normal tissues. Exposure of HUVECs to recombinant N-Slit2 resulted in an increase in VEGF levels and stimulated proliferation, migration and tube formation. These effects were blocked by an inhibitor of PI3K and thalidomide. CONCLUSIONS Robo1 and Slit2 may have important roles in the formation of gastrointestinal vascular malformation. High concentrations of Slit2 increased the levels of VEGF in HUVECs via signaling through the PI3K/Akt pathway-an effect that could be inhibited by thalidomide.
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Affiliation(s)
- Yinan Li
- Shanghai Institution of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 145 Middle Shandong Rd. GI Division, Shanghai, 200001, China
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221
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Arnold TD, Niaudet C, Pang MF, Siegenthaler J, Gaengel K, Jung B, Ferrero GM, Mukouyama YS, Fuxe J, Akhurst R, Betsholtz C, Sheppard D, Reichardt LF. Excessive vascular sprouting underlies cerebral hemorrhage in mice lacking αVβ8-TGFβ signaling in the brain. Development 2014; 141:4489-99. [PMID: 25406396 DOI: 10.1242/dev.107193] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Vascular development of the central nervous system and blood-brain barrier (BBB) induction are closely linked processes. The role of factors that promote endothelial sprouting and vascular leak, such as vascular endothelial growth factor A, are well described, but the factors that suppress angiogenic sprouting and their impact on the BBB are poorly understood. Here, we show that integrin αVβ8 activates angiosuppressive TGFβ gradients in the brain, which inhibit endothelial cell sprouting. Loss of αVβ8 in the brain or downstream TGFβ1-TGFBR2-ALK5-Smad3 signaling in endothelial cells increases vascular sprouting, branching and proliferation, leading to vascular dysplasia and hemorrhage. Importantly, BBB function in Itgb8 mutants is intact during early stages of vascular dysgenesis before hemorrhage. By contrast, Pdgfb(ret/ret) mice, which exhibit severe BBB disruption and vascular leak due to pericyte deficiency, have comparatively normal vascular morphogenesis and do not exhibit brain hemorrhage. Our data therefore suggest that abnormal vascular sprouting and patterning, not BBB dysfunction, underlie developmental cerebral hemorrhage.
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Affiliation(s)
- Thomas D Arnold
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Colin Niaudet
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Mei-Fong Pang
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Julie Siegenthaler
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Konstantin Gaengel
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Bongnam Jung
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Gina M Ferrero
- Department of Physiology and Neuroscience Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yoh-suke Mukouyama
- Laboratory of Stem Cell and Neuro-Vascular Biology, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Jonas Fuxe
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Rosemary Akhurst
- Helen Diller Cancer Center and Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christer Betsholtz
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-177 77 Stockholm, Sweden
| | - Dean Sheppard
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Louis F Reichardt
- Department of Physiology and Neuroscience Program, University of California, San Francisco, San Francisco, CA 94158, USA
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222
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Rivas V, Nogués L, Reglero C, Mayor F, Penela P. Role of G protein-coupled receptor kinase 2 in tumoral angiogenesis. Mol Cell Oncol 2014; 1:e969166. [PMID: 27308373 PMCID: PMC4905215 DOI: 10.4161/23723548.2014.969166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/22/2014] [Accepted: 08/23/2014] [Indexed: 12/26/2022]
Abstract
Downregulation of G protein-coupled receptor kinase 2 (GRK2) in endothelial cells has recently been identified as a relevant event in the tumoral angiogenic switch. Based on the effects of altering GRK2 dosage in cell and animal models, this kinase appears to act as a hub in key signaling pathways involved in vascular stabilization and remodeling. Accordingly, decreased GRK2 expression in endothelial cells accelerates tumor growth in mice by impairing the pericytes ensheathing the vessels, thereby promoting hypoxia and macrophage infiltration. These results raise new questions regarding the mechanisms by which transformed cells trigger the decrease in GRK2 observed in human breast cancer vessels and how GRK2 modulates the interactions between different cell types that occur in the tumor microenvironment.
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Affiliation(s)
- Verónica Rivas
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid); Universidad Autónoma de Madrid; Madrid, Spain; Instituto de Investigación Sanitaria La Princesa; Madrid, Spain
| | - Laura Nogués
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid); Universidad Autónoma de Madrid; Madrid, Spain; Instituto de Investigación Sanitaria La Princesa; Madrid, Spain
| | - Clara Reglero
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid); Universidad Autónoma de Madrid; Madrid, Spain; Instituto de Investigación Sanitaria La Princesa; Madrid, Spain
| | - Federico Mayor
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid); Universidad Autónoma de Madrid; Madrid, Spain; Instituto de Investigación Sanitaria La Princesa; Madrid, Spain
| | - Petronila Penela
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid); Universidad Autónoma de Madrid; Madrid, Spain; Instituto de Investigación Sanitaria La Princesa; Madrid, Spain
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223
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Rostama B, Peterson SM, Vary CPH, Liaw L. Notch signal integration in the vasculature during remodeling. Vascul Pharmacol 2014; 63:97-104. [PMID: 25464152 PMCID: PMC4304902 DOI: 10.1016/j.vph.2014.10.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/06/2014] [Accepted: 10/10/2014] [Indexed: 02/06/2023]
Abstract
Notch signaling plays many important roles in homeostasis and remodeling in the vessel wall, and serves a critical role in the communication between endothelial cells and smooth muscle cells. Within blood vessels, Notch signaling integrates with multiple pathways by mechanisms including direct protein–protein interaction, cooperative or synergistic regulation of signal cascades, and co-regulation of transcriptional targets. After establishment of the mature blood vessel, the spectrum and intensity of Notch signaling change during phases of active remodeling or disease progression. These changes can be mediated by regulation via microRNAs and protein stability or signaling, and corresponding changes in complementary signaling pathways. Notch also affects endothelial cells on a system level by regulating key metabolic components. This review will outline the most recent findings of Notch activity in blood vessels, with a focus on how Notch signals integrate with other molecular signaling pathways controlling vascular phenotype.
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Affiliation(s)
- Bahman Rostama
- Center for Molecular Medicine, Maine Medical Center Research Institute, USA
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224
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Yu L, Yan M, Simkin J, Ketcham PD, Leininger E, Han M, Muneoka K. Angiogenesis is inhibitory for mammalian digit regeneration. ACTA ACUST UNITED AC 2014; 1:33-46. [PMID: 27499862 PMCID: PMC4895301 DOI: 10.1002/reg2.24] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 08/21/2014] [Accepted: 08/27/2014] [Indexed: 12/12/2022]
Abstract
The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti‐angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551–559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium‐derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration.
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Affiliation(s)
- Ling Yu
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Mingquan Yan
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Jennifer Simkin
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Paulina D Ketcham
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Eric Leininger
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Manjong Han
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
| | - Ken Muneoka
- Division of Developmental Biology Department of Cell and Molecular Biology Tulane University New Orleans LA 79118 USA
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225
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Morioka T, Sakabe M, Ioka T, Iguchi T, Mizuta K, Hattammaru M, Sakai C, Itoh M, Sato GE, Hashimoto A, Fujita M, Okumura K, Araki M, Xin M, Pedersen RA, Utset MF, Kimura H, Nakagawa O. An important role of endothelial hairy-related transcription factors in mouse vascular development. Genesis 2014; 52:897-906. [PMID: 25264302 DOI: 10.1002/dvg.22825] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/25/2014] [Indexed: 11/06/2022]
Abstract
The Hairy-related transcription factor family of Notch- and ALK1-downstream transcriptional repressors, called Hrt/Hey/Hesr/Chf/Herp/Gridlock, has complementary and indispensable functions for vascular development. While mouse embryos null for either Hrt1/Hey1 or Hrt2/Hey2 did not show early vascular phenotypes, Hrt1/Hey1; Hrt2/Hey2 double null mice (H1(ko) /H2(ko) ) showed embryonic lethality with severe impairment of vascular morphogenesis. It remained unclear, however, whether Hrt/Hey functions are required in endothelial cells or vascular smooth muscle cells. In this study, we demonstrate that mice with endothelial-specific deletion of Hrt2/Hey2 combined with global Hrt1/Hey1 deletion (H1(ko) /H2(eko) ) show abnormal vascular morphogenesis and embryonic lethality. Their defects were characterized by the failure of vascular network formation in the yolk sac, abnormalities of embryonic vascular structures and impaired smooth muscle cell recruitment, and were virtually identical to the H1(ko) /H2(ko) phenotypes. Among signaling molecules implicated in vascular development, Robo4 expression was significantly increased and activation of Src family kinases was suppressed in endothelial cells of H1(ko) /H2(eko) embryos. The present study indicates an important role of Hrt1/Hey1 and Hrt2/Hey2 in endothelial cells during early vascular development, and further suggests involvement of Robo4 and Src family kinases in the mechanisms of embryonic vascular defects caused by the Hrt/Hey deficiency.
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Affiliation(s)
- Takashi Morioka
- Laboratory for Cardiovascular System Research, Nara Medical University Advanced Medical Research Center, Kashihara, Nara, Japan; The Second Department of Internal Medicine, Nara Medical University, Kashihara, Nara, Japan
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226
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Kushwah R, Guezguez B, Lee JB, Hopkins CI, Bhatia M. Pleiotropic roles of Notch signaling in normal, malignant, and developmental hematopoiesis in the human. EMBO Rep 2014; 15:1128-38. [PMID: 25252682 DOI: 10.15252/embr.201438842] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Notch signaling pathway is evolutionarily conserved across species and plays an important role in regulating cell differentiation, proliferation, and survival. It has been implicated in several different hematopoietic processes including early hematopoietic development as well as adult hematological malignancies in humans. This review focuses on recent developments in understanding the role of Notch signaling in the human hematopoietic system with an emphasis on hematopoietic initiation from human pluripotent stem cells and regulation within the bone marrow. Based on recent insights, we summarize potential strategies for treatment of human hematological malignancies toward the concept of targeting Notch signaling for fate regulation.
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Affiliation(s)
- Rahul Kushwah
- McMaster Stem Cell and Cancer Research Institute (SCC-RI), Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Borhane Guezguez
- McMaster Stem Cell and Cancer Research Institute (SCC-RI), Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Jung Bok Lee
- McMaster Stem Cell and Cancer Research Institute (SCC-RI), Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Claudia I Hopkins
- McMaster Stem Cell and Cancer Research Institute (SCC-RI), Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
| | - Mickie Bhatia
- McMaster Stem Cell and Cancer Research Institute (SCC-RI), Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada Department of Biochemistry and Biomedical Sciences, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada
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227
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Nielsen CM, Cuervo H, Ding VW, Kong Y, Huang EJ, Wang RA. Deletion of Rbpj from postnatal endothelium leads to abnormal arteriovenous shunting in mice. Development 2014; 141:3782-92. [PMID: 25209249 DOI: 10.1242/dev.108951] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Arteriovenous malformations (AVMs) are tortuous vessels characterized by arteriovenous (AV) shunts, which displace capillaries and shunt blood directly from artery to vein. Notch signaling regulates embryonic AV specification by promoting arterial, as opposed to venous, endothelial cell (EC) fate. To understand the essential role of endothelial Notch signaling in postnatal AV organization, we used inducible Cre-loxP recombination to delete Rbpj, a mediator of canonical Notch signaling, from postnatal ECs in mice. Deletion of endothelial Rbpj from birth resulted in features of AVMs by P14, including abnormal AV shunting and tortuous vessels in the brain, intestine and heart. We further analyzed brain AVMs, as they pose particular health risks. Consistent with AVM pathology, we found cerebral hemorrhage, hypoxia and necrosis, and neurological deficits. AV shunts originated from capillaries (and possibly venules), with the earliest detectable morphological abnormalities in AV connections by P8. Prior to AV shunt formation, alterations in EC gene expression were detected, including decreased Efnb2 and increased Pai1, which encodes a downstream effector of TGFβ signaling. After AV shunts had formed, whole-mount immunostaining showed decreased Efnb2 and increased Ephb4 expression within AV shunts, suggesting that ECs were reprogrammed from arterial to venous identity. Deletion of Rbpj from adult ECs led to tortuosities in gastrointestinal, uterine and skin vascular beds, but had mild effects in the brain. Our results demonstrate a temporal requirement for Rbpj in postnatal ECs to maintain proper artery, capillary and vein organization and to prevent abnormal AV shunting and AVM pathogenesis.
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Affiliation(s)
- Corinne M Nielsen
- Laboratory for Accelerated Vascular Research, Department of Surgery, University of California, San Francisco, CA 94143, USA
| | - Henar Cuervo
- Laboratory for Accelerated Vascular Research, Department of Surgery, University of California, San Francisco, CA 94143, USA
| | - Vivianne W Ding
- Laboratory for Accelerated Vascular Research, Department of Surgery, University of California, San Francisco, CA 94143, USA
| | - Yupeng Kong
- Laboratory for Accelerated Vascular Research, Department of Surgery, University of California, San Francisco, CA 94143, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, CA 94143, USA
| | - Rong A Wang
- Laboratory for Accelerated Vascular Research, Department of Surgery, University of California, San Francisco, CA 94143, USA
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228
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Dyer LA, Pi X, Patterson C. The role of BMPs in endothelial cell function and dysfunction. Trends Endocrinol Metab 2014; 25:472-80. [PMID: 24908616 PMCID: PMC4149816 DOI: 10.1016/j.tem.2014.05.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/21/2014] [Accepted: 05/12/2014] [Indexed: 12/23/2022]
Abstract
The bone morphogenetic protein (BMP) family of proteins has a multitude of roles throughout the body. In embryonic development, BMPs promote endothelial specification and subsequent venous differentiation. The BMP pathway also plays important roles in the adult vascular endothelium, promoting angiogenesis and mediating shear and oxidative stress. The canonical BMP pathway functions through the Smad transcription factors; however, other intracellular signaling cascades can be activated, and receptor complexes beyond the traditional type I and type II receptors add additional layers of regulation. Dysregulated BMP signaling has been linked to vascular diseases including pulmonary hypertension and atherosclerosis. This review addresses recent advances in the roles of BMP signaling in the endothelium and how BMPs affect endothelial dysfunction and human disease.
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MESH Headings
- Animals
- Atherosclerosis/etiology
- Atherosclerosis/metabolism
- Bone Morphogenetic Protein Receptors/agonists
- Bone Morphogenetic Protein Receptors/genetics
- Bone Morphogenetic Protein Receptors/metabolism
- Bone Morphogenetic Proteins/genetics
- Bone Morphogenetic Proteins/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Humans
- Hypertension/metabolism
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/metabolism
- Mice, Transgenic
- Models, Biological
- Neovascularization, Pathologic/etiology
- Neovascularization, Pathologic/metabolism
- Neovascularization, Physiologic
- Oxidative Stress
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Shear Strength
- Signal Transduction
- Stress, Physiological
- Vascular Diseases/etiology
- Vascular Diseases/metabolism
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Affiliation(s)
- Laura A Dyer
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Xinchun Pi
- New York-Presbyterian Hospital/Weill-Cornell Medical Center, New York, NY 10065, USA
| | - Cam Patterson
- New York-Presbyterian Hospital/Weill-Cornell Medical Center, New York, NY 10065, USA
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229
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Kim JD, Lee HW, Jin SW. Diversity is in my veins: role of bone morphogenetic protein signaling during venous morphogenesis in zebrafish illustrates the heterogeneity within endothelial cells. Arterioscler Thromb Vasc Biol 2014; 34:1838-45. [PMID: 25060789 DOI: 10.1161/atvbaha.114.303219] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Endothelial cells are a highly diverse group of cells which display distinct cellular responses to exogenous stimuli. Although the aptly named vascular endothelial growth factor-A signaling pathway is hailed as the most important signaling input for endothelial cells, additional factors also participate in regulating diverse aspects of endothelial behaviors and functions. Given this heterogeneity, these additional factors seem to play a critical role in creating a custom-tailored environment to regulate behaviors and functions of distinct subgroups of endothelial cells. For instance, molecular cues that modulate morphogenesis of arterial vascular beds can be distinct from those that govern morphogenesis of venous vascular beds. Recently, we have found that bone morphogenetic protein signaling selectively promotes angiogenesis from venous vascular beds without eliciting similar responses from arterial vascular beds in zebrafish, indicating that bone morphogenetic protein signaling functions as a context-dependent regulator during vascular morphogenesis. In this review, we will provide an overview of the molecular mechanisms that underlie proangiogenic effects of bone morphogenetic protein signaling on venous vascular beds in the context of endothelial heterogeneity and suggest a more comprehensive picture of the molecular mechanisms of vascular morphogenesis during development.
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Affiliation(s)
- Jun-Dae Kim
- From the Yale Cardiovascular Research Center, Section of Cardiovascular Medicine (J.-D.K., H.W.L., S.-W.J.) and Department of Internal Medicine (J.-D.K., H.W.L., S.-W.J.), Yale University School of Medicine, New Haven, CT; and School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea (S.-W.J.)
| | - Heon-Woo Lee
- From the Yale Cardiovascular Research Center, Section of Cardiovascular Medicine (J.-D.K., H.W.L., S.-W.J.) and Department of Internal Medicine (J.-D.K., H.W.L., S.-W.J.), Yale University School of Medicine, New Haven, CT; and School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea (S.-W.J.)
| | - Suk-Won Jin
- From the Yale Cardiovascular Research Center, Section of Cardiovascular Medicine (J.-D.K., H.W.L., S.-W.J.) and Department of Internal Medicine (J.-D.K., H.W.L., S.-W.J.), Yale University School of Medicine, New Haven, CT; and School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea (S.-W.J.).
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230
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Kim JD, Jin SW. A tale of two models: mouse and zebrafish as complementary models for lymphatic studies. Mol Cells 2014; 37:503-10. [PMID: 24854860 PMCID: PMC4132301 DOI: 10.14348/molcells.2014.0108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/02/2014] [Indexed: 11/27/2022] Open
Abstract
Lymphatic vessels provide essential roles in maintaining fluid homeostasis and lipid absorption. Dysfunctions of the lymphatic vessels lead to debilitating pathological conditions, collectively known as lymphedema. In addition, lymphatic vessels are a critical moderator for the onset and progression of diverse human diseases including metastatic cancer and obesity. Despite their clinical importance, there is no currently effective pharmacological therapy to regulate functions of lymphatic vessels. Recent efforts to manipulate the Vascular Endothelial Growth Factor-C (VEGFC) pathway, which is arguably the most important signaling pathway regulating lymphatic endothelial cells, to alleviate lymphedema yielded largely mixed results, necessitating identification of new targetable signaling pathways for therapeutic intervention for lymphedema. Zebrafish, a relatively new model system to investigate lymphatic biology, appears to be an ideal model to identify novel therapeutic targets for lymphatic biology. In this review, we will provide an overview of our current understanding of the lymphatic vessels in vertebrates, and discuss zebrafish as a promising in vivo model to study lymphatic vessels.
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Affiliation(s)
- Jun-Dae Kim
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Suk-Won Jin
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511, USA
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231
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The H2.0-Like Homeobox Transcription Factor Modulates Yolk Sac Vascular Remodeling in Mouse Embryos. Arterioscler Thromb Vasc Biol 2014; 34:1468-76. [DOI: 10.1161/atvbaha.114.303626] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Objective—
The H2.0-like homeobox transcription factor (HLX) plays an essential role in visceral organogenesis in mice and has been shown to regulate angiogenic sprouting in vitro and in zebrafish embryos. We therefore examined the role of HLX in vascular development in mouse and avian embryos.
Approach and Results—
In situ hybridization showed that
Hlx
is expressed in a subset of sprouting blood vessels in postnatal mouse retinas and embryos.
Hlx
expression was conserved in quail embryos and upregulated in blood vessels at the onset of circulation. In vitro assays showed that
Hlx
is dynamically regulated by growth factors and shear stress alterations. Proangiogenic vascular endothelial growth factor induces
Hlx
expression in cultured endothelial cells, whereas signals that induce stalk cell identity lead to a reduction in
Hlx
expression. HLX was also downregulated in embryos in which flow was ablated, whereas injection of a starch solution, which increases blood viscosity and therefore shear stress, causes an upregulation in HLX. HLX knockdown in vitro resulted in a reduction in tip cell marker expression and in reduced angiogenic sprouting, but
Hlx
−/−
embryos showed no defect in vascular sprouting at E8.5, E9.5, or E11.5 in vivo. Vascular remodeling of the capillary plexus was altered in
Hlx
−/−
embryos, with a modestly enlarged venous plexus and reduction of the arterial plexus.
Conclusions—
Our findings indicate not only that
Hlx
regulates sprouting in vitro, but that its role in sprouting is nonessential in vivo. We find HLX is regulated by shear stress and a subtle defect in vascular remodeling is present in knockout embryos.
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232
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Han C, Choe SW, Kim YH, Acharya AP, Keselowsky BG, Sorg BS, Lee YJ, Oh SP. VEGF neutralization can prevent and normalize arteriovenous malformations in an animal model for hereditary hemorrhagic telangiectasia 2. Angiogenesis 2014; 17:823-830. [PMID: 24957885 DOI: 10.1007/s10456-014-9436-3] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 06/05/2014] [Indexed: 12/18/2022]
Abstract
Arteriovenous malformation (AVM) refers to a vascular anomaly where arteries and veins are directly connected through a complex, tangled web of abnormal AV fistulae without a normal capillary network. Hereditary hemorrhagic telangiectasia (HHT) types 1 and 2 arise from heterozygous mutations in endoglin (ENG) and activin receptor-like kinase 1 (ALK1), respectively. HHT patients possess AVMs in various organs, and telangiectases (small AVMs) along the mucocutaneous surface. Understanding why and how AVMs develop is crucial for developing therapies to inhibit the formation, growth, or maintenance of AVMs in HHT patients. Previously, we have shown that secondary factors such as wounding are required for Alk1-deficient vessels to develop skin AVMs. Here, we present evidences that AVMs establish from nascent arteries and veins rather than from remodeling of a preexistent capillary network in the wound-induced skin AVM model. We also show that VEGF can mimic the wound effect on skin AVM formation, and VEGF-neutralizing antibody can prevent skin AVM formation and ameliorate internal bleeding in Alk1-deficient adult mice. With topical applications at different stages of AVM development, we demonstrate that the VEGF blockade can prevent the formation of AVM and cease the progression of AVM development. Taken together, the presented experimental model is an invaluable system for precise molecular mechanism of action of VEGF blockades as well as for preclinical screening of drug candidates for epistaxis and gastrointestinal bleedings.
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Affiliation(s)
- Chul Han
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610
| | - Se-Woon Choe
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610.,Department of Biomedical Engineering, Tongmyong University, Busan, Republic of Korea
| | - Yong Hwan Kim
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610
| | - Abhinav P Acharya
- J. Crayton Pruitt Family Department of Biomedical Engineering, College of Engineering, University of Florida, Gainesville, FL 32611
| | - Benjamin G Keselowsky
- J. Crayton Pruitt Family Department of Biomedical Engineering, College of Engineering, University of Florida, Gainesville, FL 32611
| | - Brian S Sorg
- J. Crayton Pruitt Family Department of Biomedical Engineering, College of Engineering, University of Florida, Gainesville, FL 32611
| | - Young-Jae Lee
- World Class University program, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, Republic of Korea
| | - S Paul Oh
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610.,World Class University program, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, Republic of Korea
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233
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Tual-Chalot S, Mahmoud M, Allinson KR, Redgrave RE, Zhai Z, Oh SP, Fruttiger M, Arthur HM. Endothelial depletion of Acvrl1 in mice leads to arteriovenous malformations associated with reduced endoglin expression. PLoS One 2014; 9:e98646. [PMID: 24896812 PMCID: PMC4045906 DOI: 10.1371/journal.pone.0098646] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 05/06/2014] [Indexed: 01/28/2023] Open
Abstract
Rare inherited cardiovascular diseases are frequently caused by mutations in genes that are essential for the formation and/or function of the cardiovasculature. Hereditary Haemorrhagic Telangiectasia is a familial disease of this type. The majority of patients carry mutations in either Endoglin (ENG) or ACVRL1 (also known as ALK1) genes, and the disease is characterized by arteriovenous malformations and persistent haemorrhage. ENG and ACVRL1 encode receptors for the TGFβ superfamily of ligands, that are essential for angiogenesis in early development but their roles are not fully understood. Our goal was to examine the role of Acvrl1 in vascular endothelial cells during vascular development and to determine whether loss of endothelial Acvrl1 leads to arteriovenous malformations. Acvrl1 was depleted in endothelial cells either in early postnatal life or in adult mice. Using the neonatal retinal plexus to examine angiogenesis, we observed that loss of endothelial Acvrl1 led to venous enlargement, vascular hyperbranching and arteriovenous malformations. These phenotypes were associated with loss of arterial Jag1 expression, decreased pSmad1/5/8 activity and increased endothelial cell proliferation. We found that Endoglin was markedly down-regulated in Acvrl1-depleted ECs showing endoglin expression to be downstream of Acvrl1 signalling in vivo. Endothelial-specific depletion of Acvrl1 in pups also led to pulmonary haemorrhage, but in adult mice resulted in caecal haemorrhage and fatal anaemia. We conclude that during development, endothelial Acvrl1 plays an essential role to regulate endothelial cell proliferation and arterial identity during angiogenesis, whilst in adult life endothelial Acvrl1 is required to maintain vascular integrity.
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Affiliation(s)
- Simon Tual-Chalot
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Marwa Mahmoud
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | | | - Rachael E. Redgrave
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Zhenhua Zhai
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - S. Paul Oh
- Department of Physiology, University of Florida, Gainesville, Florida, United States of America
| | | | - Helen M. Arthur
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
- * E-mail:
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234
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Tu J, Li Y, Hu Z, Chen Z. Radiosurgery inhibition of the Notch signaling pathway in a rat model of arteriovenous malformations. J Neurosurg 2014; 120:1385-96. [DOI: 10.3171/2013.12.jns131595] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Object
Notch signaling has been suggested to promote the development and maintenance of arteriovenous malformations (AVMs), but whether radiosurgery inhibits Notch signaling pathways in AVMs is unknown. The aim of this study was to examine molecular changes of Notch signaling pathways following radiosurgery and to explore mechanisms of radiosurgical obliteration of “nidus” vessels in a rat model of AVMs.
Methods
One hundred eleven rats received common carotid artery–to–external jugular vein anastomosis to form an arteriovenous fistula (AVF) model. Six weeks postoperatively, dilated small vessels and capillaries formed a nidus. The rats with AVFs received 25-Gy radiosurgery. The expression of Notch1 and Notch4 receptors and their ligands, Delta-like1 and Delta-like4, Jagged1, Notch downstream gene target HES1, and an apoptotic marker caspase-3 in nidus vessels in the AVF rats was examined immunohistochemically and was quantified using LAS-AF software at 7 time points over a period of 42 days postradiosurgery. The interaction events between Notch1 receptor and Jagged1, as well as Notch4 receptor and Jagged1, were quantified in nidus vessels in the AVF rats using proximity ligation assay at different time points over 42 days postradiosurgery.
Results
The expression of Notch1 and Notch4 receptors, Delta-like1, Delta-like4, Jagged1, and HES1 was observed in nidus vessels in the AVF rats pre- and postradiosurgery. Radiosurgery enhanced apoptotic activity (p < 0.05) and inhibited the expression of Notch1 and Notch4 receptors and Jagged1 in the endothelial cells of nidus vessels in the AVF rats at 1, 2, 3, 7, 21, 28, and 42 days postradiosurgery (p < 0.05). Radiosurgery suppressed the interaction events between Notch1 receptor and Jagged1 (p < 0.001) as well as Notch4 receptor and Jagged1 (p < 0.001) in the endothelial cells of nidus vessels in the AVF rats over a period of 42 days postradiosurgery. Radiosurgery induced thrombotic occlusion of nidus vessels in the AVF rats. There was a positive correlation between the percentage of fully obliterated nidus vessels and time after radiosurgery (r = 0.9324, p < 0.001).
Conclusions
Radiosurgery inhibits endothelial Notch1 and Notch4 signaling pathways in nidus vessels while inducing thrombotic occlusion of nidus vessels in a rat model of AVMs. The underlying mechanisms of radiosurgery-induced AVM shrinkage could be a combination of suppressing Notch receptor signaling in blood vessel endothelial cells, leading to a reduction in nidus vessel size and thrombotic occlusion of nidus vessels.
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Affiliation(s)
- Jian Tu
- 1Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia
| | - Yang Li
- 1Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia
| | - Zhiqiang Hu
- 2Department of Neurosurgery, the 9th Medical Clinical College of Beijing University; and
| | - Zhongbin Chen
- 3Department of Electromagnetic and Laser Biology, Beijing Institute of Radiation Medicine, Beijing, China
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235
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Seidelmann SB, Lighthouse JK, Greif DM. Development and pathologies of the arterial wall. Cell Mol Life Sci 2014; 71:1977-99. [PMID: 24071897 PMCID: PMC11113178 DOI: 10.1007/s00018-013-1478-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 01/13/2023]
Abstract
Arteries consist of an inner single layer of endothelial cells surrounded by layers of smooth muscle and an outer adventitia. The majority of vascular developmental studies focus on the construction of endothelial networks through the process of angiogenesis. Although many devastating vascular diseases involve abnormalities in components of the smooth muscle and adventitia (i.e., the vascular wall), the morphogenesis of these layers has received relatively less attention. Here, we briefly review key elements underlying endothelial layer formation and then focus on vascular wall development, specifically on smooth muscle cell origins and differentiation, patterning of the vascular wall, and the role of extracellular matrix and adventitial progenitor cells. Finally, we discuss select human diseases characterized by marked vascular wall abnormalities. We propose that continuing to apply approaches from developmental biology to the study of vascular disease will stimulate important advancements in elucidating disease mechanism and devising novel therapeutic strategies.
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MESH Headings
- Angiogenic Proteins/genetics
- Angiogenic Proteins/metabolism
- Animals
- Arteries/growth & development
- Arteries/metabolism
- Arteries/pathology
- Cardiovascular Diseases/genetics
- Cardiovascular Diseases/metabolism
- Cardiovascular Diseases/pathology
- Cell Differentiation
- Cell Lineage/genetics
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/growth & development
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Gene Expression Regulation, Developmental
- Humans
- Morphogenesis/genetics
- Muscle, Smooth, Vascular/growth & development
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neovascularization, Pathologic
- Neovascularization, Physiologic
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Affiliation(s)
- Sara B. Seidelmann
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, 300 George St., Rm 773J, New Haven, CT 06511 USA
| | - Janet K. Lighthouse
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, 300 George St., Rm 773J, New Haven, CT 06511 USA
| | - Daniel M. Greif
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale Cardiovascular Research Center, Yale University School of Medicine, 300 George St., Rm 773J, New Haven, CT 06511 USA
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236
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Genetic variants of Adam17 differentially regulate TGFβ signaling to modify vascular pathology in mice and humans. Proc Natl Acad Sci U S A 2014; 111:7723-8. [PMID: 24812125 DOI: 10.1073/pnas.1318761111] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Outcome of TGFβ1 signaling is context dependent and differs between individuals due to germ-line genetic variation. To explore innate genetic variants that determine differential outcome of reduced TGFβ1 signaling, we dissected the modifier locus Tgfbm3, on mouse chromosome 12. On a NIH/OlaHsd genetic background, the Tgfbm3b(C57) haplotype suppresses prenatal lethality of Tgfb1(-/-) embryos and enhances nuclear accumulation of mothers against decapentaplegic homolog 2 (Smad2) in embryonic cells. Amino acid polymorphisms within a disintegrin and metalloprotease 17 (Adam17) can account, at least in part, for this Tgfbm3b effect. ADAM17 is known to down-regulate Smad2 signaling by shedding the extracellular domain of TGFβRI, and we show that the C57 variant is hypomorphic for down-regulation of Smad2/3-driven transcription. Genetic variation at Tgfbm3 or pharmacological inhibition of ADAM17, modulates postnatal circulating endothelial progenitor cell (CEPC) numbers via effects on TGFβRI activity. Because CEPC numbers correlate with angiogenic potential, this suggests that variant Adam17 is an innate modifier of adult angiogenesis, acting through TGFβR1. To determine whether human ADAM17 is also polymorphic and interacts with TGFβ signaling in human vascular disease, we investigated hereditary hemorrhagic telangiectasia (HHT), which is caused by mutations in TGFβ/bone morphogenetic protein receptor genes, ENG, encoding endoglin (HHT1), or ACVRL1 encoding ALK1 (HHT2), and considered a disease of excessive abnormal angiogenesis. HHT manifests highly variable incidence and severity of clinical features, ranging from small mucocutaneous telangiectases to life-threatening visceral and cerebral arteriovenous malformations (AVMs). We show that ADAM17 SNPs associate with the presence of pulmonary AVM in HHT1 but not HHT2, indicating genetic variation in ADAM17 can potentiate a TGFβ-regulated vascular disease.
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Abstract
Abstract
Lymphatic vasculature is increasingly recognized as an important factor both in the regulation of normal tissue homeostasis and immune response and in many diseases, such as inflammation, cancer, obesity, and hypertension. In the last few years, in addition to the central role of vascular endothelial growth factor (VEGF)-C/VEGF receptor-3 signaling in lymphangiogenesis, significant new insights were obtained about Notch, transforming growth factor β/bone morphogenetic protein, Ras, mitogen-activated protein kinase, phosphatidylinositol 3 kinase, and Ca2+/calcineurin signaling pathways in the control of growth and remodeling of lymphatic vessels. An emerging picture of lymphangiogenic signaling is complex and in many ways distinct from the regulation of angiogenesis. This complexity provides new challenges, but also new opportunities for selective therapeutic targeting of lymphatic vasculature.
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238
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LI SHU, WANG RONG, WANG YAJIE, LI HAOWEN, ZHENG JIAN, DUAN RAN, ZHAO JIZONG. Receptors of the Notch signaling pathway are associated with hemorrhage of brain arteriovenous malformations. Mol Med Rep 2014; 9:2233-8. [DOI: 10.3892/mmr.2014.2061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 02/27/2014] [Indexed: 11/06/2022] Open
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239
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Sakurai T, Woolls MJ, Jin SW, Murakami M, Simons M. Inter-cellular exchange of cellular components via VE-cadherin-dependent trans-endocytosis. PLoS One 2014; 9:e90736. [PMID: 24603875 PMCID: PMC3946293 DOI: 10.1371/journal.pone.0090736] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/05/2014] [Indexed: 11/18/2022] Open
Abstract
Cell-cell communications typically involve receptor-mediated signaling initiated by soluble or cell-bound ligands. Here, we report a unique mode of endocytosis: proteins originating from cell-cell junctions and cytosolic cellular components from the neighboring cell are internalized, leading to direct exchange of cellular components between two adjacent endothelial cells. VE-cadherins form transcellular bridges between two endothelial cells that are the basis of adherence junctions. At such adherens junction sites, we observed the movement of the entire VE-cadherin molecule from one endothelial cell into the other with junctional and cytoplasmic components. This phenomenon, here termed trans-endocytosis, requires the establishment of a VE-cadherin homodimer in trans with internalization proceeding in a Rac1-, and actomyosin-dependent manner. Importantly, the trans-endocytosis is not dependent on any known endocytic pathway including clathrin-dependent endocytosis, macropinocytosis or phagocytosis. This novel form of cell-cell communications, leading to a direct exchange of cellular components, was observed in 2D and 3D-cultured endothelial cells as well as in the developing zebrafish vasculature.
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Affiliation(s)
- Takashi Sakurai
- Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
| | - Melissa J. Woolls
- Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Suk-Won Jin
- Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Masahiro Murakami
- Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Michael Simons
- Yale Cardiovascular Research Center and Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
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240
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Kim JD, Kim J. Alk3/Alk3b and Smad5 mediate BMP signaling during lymphatic development in zebrafish. Mol Cells 2014; 37:270-4. [PMID: 24608800 PMCID: PMC3969049 DOI: 10.14348/molcells.2014.0005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 01/28/2014] [Indexed: 12/02/2022] Open
Abstract
Lymphatic vessels are essential to regulate interstitial fluid homeostasis and diverse immune responses. A number of crucial factors, such as VEGFC, SOX18, PROX1, FOX2C, and GJC2, have been implicated in differentiation and/or maintenance of lymphatic endothelial cells (LECs). In humans, dysregulation of these genes is known to cause lymphedema, a debilitating condition which adversely impacts the quality of life of affected individuals. However, there are no currently available pharmacological treatments for lymphedema, necessitating identification of additional factors modulating lymphatic development and function which can be targeted for therapy. In this report, we investigate the function of genes associated with Bone Morphogenetic Protein (BMP) signaling in lymphatic development using zebrafish embryos. The knock-down of BMP type II receptors, Bmpr2a and Bmpr2b, and type I receptors, Alk3 and Alk3b, as well as SMAD5, an essential cellular mediator of BMP signaling, led to distinct lymphatic defects in developing zebrafish. Therefore, it appears that each constituent of the BMP signaling pathway may have a unique function during lymphatic development. Taken together, our data demonstrate that BMP signaling is essential for normal lymphatic vessel development in zebrafish.
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Affiliation(s)
- Jun-Dae Kim
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511,
USA
| | - Jongmin Kim
- Department of Life Systems, Sookmyung Women’s University, Seoul 140-742,
Korea
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241
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Marcelo KL, Sills TM, Coskun S, Vasavada H, Sanglikar S, Goldie LC, Hirschi KK. Hemogenic endothelial cell specification requires c-Kit, Notch signaling, and p27-mediated cell-cycle control. Dev Cell 2014; 27:504-15. [PMID: 24331925 DOI: 10.1016/j.devcel.2013.11.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 09/01/2013] [Accepted: 11/04/2013] [Indexed: 02/05/2023]
Abstract
Delineating the mechanism or mechanisms that regulate the specification of hemogenic endothelial cells from primordial endothelium is critical for optimizing their derivation from human stem cells for clinical therapies. We previously determined that retinoic acid (RA) is required for hemogenic specification, as well as cell-cycle control, of endothelium during embryogenesis. Herein, we define the molecular signals downstream of RA that regulate hemogenic endothelial cell development and demonstrate that cell-cycle control is required for this process. We found that re-expression of c-Kit in RA-deficient (Raldh2(-/-)) primordial endothelium induced Notch signaling and p27 expression, which restored cell-cycle control and rescued hemogenic endothelial cell specification and function. Re-expression of p27 in RA-deficient and Notch-inactivated primordial endothelial cells was sufficient to correct their defects in cell-cycle regulation and hemogenic endothelial cell development. Thus, RA regulation of hemogenic endothelial cell specification requires c-Kit, notch signaling, and p27-mediated cell-cycle control.
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Affiliation(s)
- Kathrina L Marcelo
- Interdepartmental Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Tiffany M Sills
- Interdisciplinary Program in Cell and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Suleyman Coskun
- Yale Cardiovascular Research Center and Yale Stem Cell Center, Yale University School of Medicine, 300 George Street, New Haven, CT 06511, USA
| | - Hema Vasavada
- Yale Cardiovascular Research Center and Yale Stem Cell Center, Yale University School of Medicine, 300 George Street, New Haven, CT 06511, USA
| | - Supriya Sanglikar
- Yale Cardiovascular Research Center and Yale Stem Cell Center, Yale University School of Medicine, 300 George Street, New Haven, CT 06511, USA
| | - Lauren C Goldie
- Interdepartmental Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Karen K Hirschi
- Interdepartmental Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Interdisciplinary Program in Cell and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Center for Cell and Gene Therapy, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Yale Cardiovascular Research Center and Yale Stem Cell Center, Yale University School of Medicine, 300 George Street, New Haven, CT 06511, USA.
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242
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Baello S, Iqbal M, Bloise E, Javam M, Gibb W, Matthews SG. TGF-β1 regulation of multidrug resistance P-glycoprotein in the developing male blood-brain barrier. Endocrinology 2014; 155:475-84. [PMID: 24265456 DOI: 10.1210/en.2013-1472] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
P-glycoprotein (P-gp), an efflux transporter encoded by the abcb1 gene, protects the developing fetal brain. Levels of P-gp in endothelial cells of the blood-brain barrier (BBB) increase dramatically during the period of peak brain growth. This is coincident with increased release of TGF-β1 by astrocytes and neurons. Although TGF-β1 has been shown to modulate P-gp activity in a number of cell types, little is known about how TGF-β1 regulates brain protection. In the present study, we hypothesized that TGF-β1 increases abcb1 expression and P-gp activity in fetal and postnatal BBB in an age-dependent manner. We found TGF-β1 to potently regulate abcb1 mRNA and P-gp function. TGF-β1 increased P-gp function in brain endothelial cells (BECs) derived from fetal and postnatal male guinea pigs. These effects were more pronounced earlier in gestation when compared with BECs derived postnatally. To investigate the signaling pathways involved, BECs derived at gestational day 50 and postnatal day 14 were exposed to ALK1 and ALK5 inhibitors and agonists. Through inhibition of ALK5, we demonstrated that ALK5 is required for the TGF-β1 effects on P-gp function. Activation of ALK1, by the agonist BMP-9, produced similar results to TGF-β1 on P-gp function. However, TGF-β1 signaling through the ALK1 pathway is age-dependent as dorsomorphin, an ALK1 inhibitor, attenuated TGF-β1-mediated effects in BECs derived at postnatal day 14 but not in those derived at gestational day 50. In conclusion, TGF-β1 regulates P-gp at the fetal and neonatal BBB and both ALK5 and ALK1 pathways are implicated in the regulation of P-gp function. Aberrations in TGF-β1 levels at the developing BBB may lead to substantial changes in fetal brain exposure to P-gp substrates, triggering consequences for brain development.
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Affiliation(s)
- Stephanie Baello
- Department of Physiology (S.B., M.I., E.B., M.J., S.G.M.), Obstetrics and Gynecology (S.G.M.), and Medicine (S.G.M.), Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; and Department of Obstetrics and Gynecology (W.G.), and Cellular and Molecular Medicine (W.G.), Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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243
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Notch1 and 4 signaling responds to an increasing vascular wall shear stress in a rat model of arteriovenous malformations. BIOMED RESEARCH INTERNATIONAL 2014; 2014:368082. [PMID: 24563863 PMCID: PMC3915856 DOI: 10.1155/2014/368082] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/11/2013] [Indexed: 11/17/2022]
Abstract
Notch signaling is suggested to promote the development and maintenance of cerebral arteriovenous malformations (AVMs), and an increasing wall shear stress (WSS) contributes to AVM rupture. Little is known about whether WSS impacts Notch signaling, which is important for understanding the angiogenesis of AVMs. WSS was measured in arteriovenous fistulas (AVF) surgically created in 96 rats at different time points over a period of 84 days. The expression of Notch receptors 1 and 4 and their ligands, Delta1 and 4, Jagged1, and Notch downstream gene target Hes1 was quantified in “nidus” vessels. The interaction events between Notch receptors and their ligands were quantified using proximity ligation assay. There was a positive correlation between WSS and time (r = 0.97; P < 0.001). The expression of Notch receptors and their ligands was upregulated following AVF formation. There was a positive correlation between time and the number of interactions between Notch receptors and their ligands aftre AVF formation (r = 0.62, P < 0.05) and a positive correlation between WSS and the number of interactions between Notch receptors and their ligands (r = 0.87, P < 0.005). In conclusion, an increasing WSS may contribute to the angiogenesis of AVMs by activation of Notch signaling.
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Abstract
Hey bHLH transcription factors are direct targets of canonical Notch signaling. The three mammalian Hey proteins are closely related to Hes proteins and they primarily repress target genes by either directly binding to core promoters or by inhibiting other transcriptional activators. Individual candidate gene approaches and systematic screens identified a number of Hey target genes, which often encode other transcription factors involved in various developmental processes. Here, we review data on interaction partners and target genes and conclude with a model for Hey target gene regulation. Furthermore, we discuss how expression of Hey proteins affects processes like cell fate decisions and differentiation, e.g., in cardiovascular, skeletal, and neural development or oncogenesis and how this relates to the observed developmental defects and phenotypes observed in various knockout mice.
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Affiliation(s)
- David Weber
- Developmental Biochemistry, Theodor-Boveri-Institute/Biocenter, Wuerzburg University, Wuerzburg, Germany
| | - Cornelia Wiese
- Developmental Biochemistry, Theodor-Boveri-Institute/Biocenter, Wuerzburg University, Wuerzburg, Germany
| | - Manfred Gessler
- Developmental Biochemistry, Theodor-Boveri-Institute/Biocenter, Wuerzburg University, Wuerzburg, Germany; Comprehensive Cancer Center Mainfranken, Wuerzburg University, Wuerzburg, Germany.
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245
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Fan J, Ponferrada VG, Sato T, Vemaraju S, Fruttiger M, Gerhardt H, Ferrara N, Lang RA. Crim1 maintains retinal vascular stability during development by regulating endothelial cell Vegfa autocrine signaling. Development 2013; 141:448-59. [PMID: 24353059 PMCID: PMC3879820 DOI: 10.1242/dev.097949] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Angiogenesis defines the process in which new vessels grow from existing vessels. Using the mouse retina as a model system, we show that cysteine-rich motor neuron 1 (Crim1), a type I transmembrane protein, is highly expressed in angiogenic endothelial cells. Conditional deletion of the Crim1 gene in vascular endothelial cells (VECs) causes delayed vessel expansion and reduced vessel density. Based on known Vegfa binding by Crim1 and Crim1 expression in retinal vasculature, where angiogenesis is known to be Vegfa dependent, we tested the hypothesis that Crim1 is involved in the regulation of Vegfa signaling. Consistent with this hypothesis, we showed that VEC-specific conditional compound heterozygotes for Crim1 and Vegfa exhibit a phenotype that is more severe than each single heterozygote and indistinguishable from that of the conditional homozygotes. We further showed that human CRIM1 knockdown in cultured VECs results in diminished phosphorylation of VEGFR2, but only when VECs are required to rely on an autocrine source of VEGFA. The effect of CRIM1 knockdown on reducing VEGFR2 phosphorylation was enhanced when VEGFA was also knocked down. Finally, an anti-VEGFA antibody did not enhance the effect of CRIM1 knockdown in reducing VEGFR2 phosphorylation caused by autocrine signaling, but VEGFR2 phosphorylation was completely suppressed by SU5416, a small-molecule VEGFR2 kinase inhibitor. These data are consistent with a model in which Crim1 enhances the autocrine signaling activity of Vegfa in VECs at least in part via Vegfr2.
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Affiliation(s)
- Jieqing Fan
- Divisions of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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246
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Wang Y, Pan L, Moens CB, Appel B. Notch3 establishes brain vascular integrity by regulating pericyte number. Development 2013; 141:307-17. [PMID: 24306108 DOI: 10.1242/dev.096107] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Brain pericytes are important regulators of brain vascular integrity, permeability and blood flow. Deficiencies of brain pericytes are associated with neonatal intracranial hemorrhage in human fetuses, as well as stroke and neurodegeneration in adults. Despite the important functions of brain pericytes, the mechanisms underlying their development are not well understood and little is known about how pericyte density is regulated across the brain. The Notch signaling pathway has been implicated in pericyte development, but its exact roles remain ill defined. Here, we report an investigation of the Notch3 receptor using zebrafish as a model system. We show that zebrafish brain pericytes express notch3 and that notch3 mutant zebrafish have a deficit of brain pericytes and impaired blood-brain barrier function. Conditional loss- and gain-of-function experiments provide evidence that Notch3 signaling positively regulates brain pericyte proliferation. These findings establish a new role for Notch signaling in brain vascular development whereby Notch3 signaling promotes expansion of the brain pericyte population.
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Affiliation(s)
- Yuying Wang
- Departments of Pediatrics and Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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Yao Y, Yao J, Radparvar M, Blazquez-Medela AM, Guihard PJ, Jumabay M, Boström KI. Reducing Jagged 1 and 2 levels prevents cerebral arteriovenous malformations in matrix Gla protein deficiency. Proc Natl Acad Sci U S A 2013; 110:19071-6. [PMID: 24191040 PMCID: PMC3839731 DOI: 10.1073/pnas.1310905110] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cerebral arteriovenous malformations (AVMs) are common vascular malformations, which may result in hemorrhagic strokes and neurological deficits. Bone morphogenetic protein (BMP) and Notch signaling are both involved in the development of cerebral AVMs, but the cross-talk between the two signaling pathways is poorly understood. Here, we show that deficiency of matrix Gla protein (MGP), a BMP inhibitor, causes induction of Notch ligands, dysregulation of endothelial differentiation, and the development of cerebral AVMs in MGP null (Mgp(-/-)) mice. Increased BMP activity due to the lack of MGP induces expression of the activin receptor-like kinase 1, a BMP type I receptor, in cerebrovascular endothelium. Subsequent activation of activin receptor-like kinase 1 enhances expression of Notch ligands Jagged 1 and 2, which increases Notch activity and alters the expression of Ephrin B2 and Ephrin receptor B4, arterial and venous endothelial markers, respectively. Reducing the expression of Jagged 1 and 2 in the Mgp(-/-) mice by crossing them with Jagged 1 or 2 deficient mice reduces Notch activity, normalizes endothelial differentiation, and prevents cerebral AVMs, but not pulmonary or renal AVMs. Our results suggest that Notch signaling mediates and can modulate changes in BMP signaling that lead to cerebral AVMs.
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Affiliation(s)
- Yucheng Yao
- Division of Cardiology, David Geffen School of Medicine at UCLA and
| | - Jiayi Yao
- Division of Cardiology, David Geffen School of Medicine at UCLA and
| | - Melina Radparvar
- Division of Cardiology, David Geffen School of Medicine at UCLA and
| | | | | | - Medet Jumabay
- Division of Cardiology, David Geffen School of Medicine at UCLA and
| | - Kristina I. Boström
- Division of Cardiology, David Geffen School of Medicine at UCLA and
- Molecular Biology Institute, University of California, Los Angeles, CA 90095-1679
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249
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A functional genomic approach reveals the transcriptional role of EDD in the expression and function of angiogenesis regulator ACVRL1. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:1309-19. [PMID: 24189493 DOI: 10.1016/j.bbagrm.2013.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 10/18/2013] [Accepted: 10/28/2013] [Indexed: 11/22/2022]
Abstract
EDD (E3 isolated by differential display) was initially isolated as a progestin-regulated gene in breast cancer cells, and represents the human ortholog of the Drosophila melanogaster hyperplastic discs gene (hyd). It encodes a highly conserved and predominantly nuclear ubiquitin E3 ligase of the HECT family, with potential multifunctional roles in development and tumorigenesis. In this study, we further examined the largely uncharacterized role of EDD in transcriptional regulation by uncovering the spectrum of its direct target genes at a genome-wide level. Use of a systematic approach that integrates gene expression and chromatin binding profiling identified several candidate EDD-target genes, one of which is ACVRL1, a TGF-β receptor with functional implications in blood vessel development. Further characterization revealed a negative regulation of ACVRL1 gene expression by EDD that is exerted at the promoter. Consistent with the aberrant upregulation of ACVRL1 and downstream Smad signaling, abrogation of EDD led to deregulated vessel development and endothelial cell motility. Collectively, these results extended the known cellular roles of EDD to critical functions in transcriptional regulation as well as angiogenesis, and may provide mechanistic explanations for EDD's tumorigenic and developmental roles.
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250
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Osório C, Chacón PJ, Kisiswa L, White M, Wyatt S, Rodríguez-Tébar A, Davies AM. Growth differentiation factor 5 is a key physiological regulator of dendrite growth during development. Development 2013; 140:4751-62. [PMID: 24173804 PMCID: PMC3833432 DOI: 10.1242/dev.101378] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dendrite size and morphology are key determinants of the functional properties of neurons. Here, we show that growth differentiation factor 5 (GDF5), a member of the bone morphogenetic protein (BMP) subclass of the transforming growth factor β superfamily with a well-characterised role in limb morphogenesis, is a key regulator of the growth and elaboration of pyramidal cell dendrites in the developing hippocampus. Pyramidal cells co-express GDF5 and its preferred receptors, BMP receptor 1B and BMP receptor 2, during development. In culture, GDF5 substantially increased dendrite, but not axon, elongation from these neurons by a mechanism that depends on activation of SMADs 1/5/8 and upregulation of the transcription factor HES5. In vivo, the apical and basal dendritic arbours of pyramidal cells throughout the hippocampus were markedly stunted in both homozygous and heterozygous Gdf5 null mutants, indicating that dendrite size and complexity are exquisitely sensitive to the level of endogenous GDF5 synthesis.
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Affiliation(s)
- Catarina Osório
- School of Biosciences, Cardiff University, Cardiff CF10 3AT, UK
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