title: Role of nanomechanics in canonical and noncanonical pro-angiogenic ligand/VEGF receptor-2 activation.
abstract: Vascular endothelial growth factor receptor-2 (VEGFR2) is an endothelial cell receptor that plays a pivotal role in physiologic and pathologic angiogenesis and is a therapeutic target for angiogenesis-dependent diseases, including cancer. By leveraging on a dedicated nanomechanical biosensor, we investigated the nanoscale mechanical phenomena intertwined with VEGFR2 surface recognition by its prototypic ligand VEGF-A and its noncanonical ligand gremlin. We found that the two ligands bind the immobilized extracellular domain of VEGFR2 (sVEGFR2) with comparable binding affinity. Nevertheless, they interact with sVEGFR2 with different binding kinetics and drive different in-plane piconewton intermolecular forces, suggesting that the binding of VEGF-A or gremlin induces different conformational changes in sVEGFR2. These behaviors can be effectively described in terms of a different "nanomechanical affinity" of the two ligands for sVEGFR2, about 16-fold higher for VEGF-A with respect to gremlin. Such nanomechanical differences affect the biological activity driven by the two angiogenic factors in endothelial cells, as evidenced by a more rapid VEGFR2 clustering and a more potent mitogenic response triggered by VEGF-A in respect to gremlin. Together, these data point to surface intermolecular interactions on cell membrane between activated receptors as a key modulator of the intracellular signaling cascade.
authors.affiliation: Chemistry for Technologies Laboratory and INSTM, School of Engineering, University of Brescia, Via Branze, 38, 25123 Brescia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Maiolo
authors.forename: Stefania
authors.initials: S
authors.lastname: Mitola
authors.forename: Daria
authors.initials: D
authors.lastname: Leali
authors.forename: Giulio
authors.initials: G
authors.lastname: Oliviero
authors.forename: Cosetta
authors.initials: C
authors.lastname: Ravelli
authors.forename: Antonella
authors.initials: A
authors.lastname: Bugatti
authors.forename: Laura E
authors.initials: LE
authors.lastname: Depero
authors.forename: Marco
authors.initials: M
authors.lastname: Presta
authors.forename: Paolo
authors.initials: P
authors.lastname: Bergese
mesh_terms: D016207:Cytokines; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008024:Ligands; D055595:Mechanical Phenomena; D036103:Nanotechnology / Q000379:methods*; D018919:Neovascularization, Physiologic; D020349:Surface Plasmon Resonance / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins; D008024:Ligands; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; C113178:Grem1 protein, mouse