Cyclic adenosine monophosphate-response element-binding protein mediates the proangiogenic or proinflammatory activity of gremlin.
OBJECTIVE
Angiogenesis and inflammation are closely related processes. Gremlin is a novel noncanonical vascular endothelial growth factor receptor-2 (VEGFR2) ligand that induces a proangiogenic response in endothelial cells (ECs). Here, we investigated the role of the cyclic adenosine monophosphate-response element (CRE)-binding protein (CREB) in mediating the proinflammatory and proangiogenic responses of ECs to gremlin.


RESULTS
Gremlin induces a proinflammatory response in ECs, leading to reactive oxygen species and cyclic adenosine monophosphate production and the upregulation of proinflammatory molecules involved in leukocyte extravasation, including chemokine (C-C motif) ligand-2 (Ccl2) and Ccl7, chemokine (C-X-C motif) ligand-1 (Cxcl1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). Accordingly, gremlin induces the VEGFR2-dependent phosphorylation, nuclear translocation, and transactivating activity of CREB in ECs. CREB activation mediates the early phases of the angiogenic response to gremlin, including stimulation of EC motility and permeability, and leads to monocyte/macrophage adhesion to ECs and their extravasation. All these effects are inhibited by EC transfection with a dominant-negative CREB mutant or with a CREB-binding protein-CREB interaction inhibitor that competes for CREB/CRE binding. Also, both recombinant gremlin and gremlin-expressing tumor cells induce proinflammatory/proangiogenic responses in vivo that are suppressed by the anti-inflammatory drug hydrocortisone. Similar effects were induced by the canonical VEGFR2 ligand VEGF-A165.


CONCLUSIONS
Together, the results underline the tight cross-talk between angiogenesis and inflammation and demonstrate a crucial role of CREB activation in the modulation of the VEGFR2-mediated proinflammatory/proangiogenic response of ECs to gremlin.
From the Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy (M.C., E.M., C.R., E.G., M.P., S.M.); Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, Campus Cantoblanco, Madrid, Spain (G.A.); and Centre for Experimental Medicine, Queen's University Belfast, ICS-A, Grosvenor Road, Belfast BT12 6BA, UK (I.H.A., D.P.B.).
Michela
M
Corsini
Emanuela
E
Moroni
Cosetta
C
Ravelli
Germán
G
Andrés
Elisabetta
E
Grillo
Imran H
IH
Ali
Derek P
DP
Brazil
Marco
M
Presta
Stefania
S
Mitola
D021581:Active Transport, Cell Nucleus; D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002199:Capillary Permeability; D002448:Cell Adhesion; D002465:Cell Movement; D018932:Chemokine CCL2 / Q000378:metabolism; D054410:Chemokine CCL7 / Q000378:metabolism; D054360:Chemokine CXCL1 / Q000378:metabolism; D002642:Chick Embryo; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines; D042783:Endothelial Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D061307:Human Umbilical Vein Endothelial Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000517:prevention & control; D018836:Inflammation Mediators / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D061986:MCF-7 Cells; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D000893:Anti-Inflammatory Agents; D018932:Chemokine CCL2; D054410:Chemokine CCL7; D054360:Chemokine CXCL1; D017077:Culture Media, Conditioned; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein; D016207:Cytokines; D006854:Hydrocortisone; D018836:Inflammation Mediators; D018799:Intercellular Adhesion Molecule-1; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D017382:Reactive Oxygen Species; D019010:Vascular Cell Adhesion Molecule-1; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; C115163:CREB1 protein, human; C491768:Ccl2 protein, mouse; C515451:Ccl7 protein, mouse; C113178:Grem1 protein, mouse; C492004:Creb1 protein, mouse; C475895:Cxcl1 protein, mouse; C486399:GREM1 protein, human; C090509:Icam1 protein, mouse
cyclic AMP response element–binding protein