title: EphB4 forward signalling mediates angiogenesis caused by CCM3/PDCD10-ablation.
abstract: CCM3, also named as PDCD10, is a ubiquitous protein expressed in nearly all tissues and in various types of cells. It is essential for vascular development and post-natal vessel maturation. Loss-of-function mutation of CCM3 predisposes for the familial form of cerebral cavernous malformation (CCM). We have previously shown that knock-down of CCM3 stimulated endothelial angiogenesis via impairing DLL4-Notch signalling; moreover, loss of endothelial CCM3 stimulated tumour angiogenesis and promoted tumour growth. The present study was designed to further elucidate the inside signalling pathway involved in CCM3-ablation-mediated angiogenesis. Here we report for the first time that silencing endothelial CCM3 led to a significant up-regulation of EphB4 mRNA and protein expression and to an increased kinase activity of EphB4, concomitantly accompanied by an activation of Erk1/2, which was reversed by treatment with the specific EphB4 kinase inhibitor NVP-BHG712 (NVP), indicating that silencing CCM3 activates EphB4 kinase forward signalling. Furthermore, treatment with NVP rescued the hyper-angiogenic phenotype induced by knock-down of endothelial CCM3 in vitro and in vivo. Additional study demonstrated that the activation of EphB4 forward signalling in endothelial cells under basal condition and after CCM3-silence was modulated by DLL4/Notch signalling, relying EphB4 at downstream of DLL4/Notch signalling. We conclude that angiogenesis induced by CCM3-silence is mediated by the activation of EphB4 forward signalling. The identified endothelial signalling pathway of CCM3-DLL4/Notch-EphB4-Erk1/2 may provide an insight into mechanism of CCM3-ablation-mediated angiogenesis and could potentially contribute to novel therapeutic concepts for disrupting aberrant angiogenesis in CCM and in hyper-vascularized tumours.
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.|Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Chao
authors.initials: C
authors.lastname: You
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.|Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Dammann
authors.affiliation: Institute of Neuropathology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Kathy
authors.initials: K
authors.lastname: Keyvani
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.
authors.forename: Ilonka
authors.initials: I
authors.lastname: Kreitschmann-Andermahr
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sure
authors.affiliation: Department of Neurosurgery, University of Duisburg-Essen, Essen, Germany.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008819:Mice, Nude; D018919:Neovascularization, Physiologic; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D036224:Receptor, EphB4 / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C495390:PDCD10 protein, human; D047428:Protein Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D051880:Receptors, Notch; D036224:Receptor, EphB4; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: CCM3/PDCD10; DLL4-Notch signalling; EphB4 forward signalling; angiogenesis