title: VEGF-A isoforms differentially regulate ATF-2-dependent VCAM-1 gene expression and endothelial-leukocyte interactions.
abstract: Vascular endothelial growth factor A (VEGF-A) regulates many aspects of vascular physiology. VEGF-A stimulates signal transduction pathways that modulate endothelial outputs such as cell migration, proliferation, tubulogenesis, and cell-cell interactions. Multiple VEGF-A isoforms exist, but the biological significance of this is unclear. Here we analyzed VEGF-A isoform-specific stimulation of VCAM-1 gene expression, which controls endothelial-leukocyte interactions, and show that this is dependent on both ERK1/2 and activating transcription factor-2 (ATF-2). VEGF-A isoforms showed differential ERK1/2 and p38 MAPK phosphorylation kinetics. A key feature of VEGF-A isoform-specific ERK1/2 activation and nuclear translocation was increased phosphorylation of ATF-2 on threonine residue 71 (T71). Using reverse genetics, we showed ATF-2 to be functionally required for VEGF-A-stimulated endothelial VCAM-1 gene expression. ATF-2 knockdown blocked VEGF-A-stimulated VCAM-1 expression and endothelial-leukocyte interactions. ATF-2 was also required for other endothelial cell outputs, such as cell migration and tubulogenesis. In contrast, VCAM-1 was essential only for promoting endothelial-leukocyte interactions. This work presents a new paradigm for understanding how soluble growth factor isoforms program complex cellular outputs and responses by modulating signal transduction pathways.
authors: Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors: Gareth W
authors: GW
authors: Fearnley
authors: Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors: Adam F
authors: AF
authors: Odell
authors: Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors: Antony M
authors: AM
authors: Latham
authors: Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United KingdomLeeds Vascular Institute, Leeds General Infirmary, Leeds LS1 3EX, United Kingdom.
authors: Nadeem A
authors: NA
authors: Mughal
authors: Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors: Alexander F
authors: AF
authors: Bruns
authors: Fios Genomics, Edinburgh EH16 4UX, United Kingdom.
authors: Nicholas J
authors: NJ
authors: Burgoyne
authors: Leeds Vascular Institute, Leeds General Infirmary, Leeds LS1 3EX, United Kingdom.
authors: Shervanthi
authors: S
authors: Homer-Vanniasinkam
authors: Division of Cardiovascular Biology and Medicine, Rayne Institute, University College London, London, United Kingdom.
authors: Ian C
authors: IC
authors: Zachary
authors: German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
authors: Monica C
authors: MC
authors: Hollstein
authors: Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors: Stephen B
authors: SB
authors: Wheatcroft
authors: Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom s.ponnambalam@leeds.ac.uk.
authors: Sreenivasan
authors: S
authors: Ponnambalam
mesh_terms: D051698:Activating Transcription Factor 2 / Q000235:genetics / Q000378:metabolism*; D002465:Cell Movement; D049109:Cell Proliferation; D015870:Gene Expression; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D010766:Phosphorylation; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism
chemical_list: C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D020033:Protein Isoforms; C467484:VEGFA protein, human; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A; C000588866:KDR protein, human; D040301:Vascular Endothelial Growth Factor Receptor-2