title: Outside-in signaling pathway linked to CD146 engagement in human endothelial cells.
abstract: CD146 (S-Endo 1 Ag or MUC18) is a transmembrane glycoprotein expressed on endothelial cells on the whole vascular tree. CD146 is located at the intercellular junction where it plays a role in the cohesion of the endothelial monolayer. CD146 engagement initiates an outside-in signaling pathway involving the protein tyrosine kinases FYN and FAK as well as paxillin. Here we report that CD146 engagement by its specific monoclonal antibody in human umbilical vein endothelial cells induces a Ca(2+) influx that is sensitive to thapsigargin and EGTA treatment, indicating that CD146 engagement initiates a store-operated calcium mobilization. In addition, biochemical and pharmacological analysis revealed that CD146 engagement initiates the tyrosine phosphorylation of phospholipase C-gamma, Pyk2, and p130(Cas). Pharmacological inhibition of Ca(2+) flux with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acetoxymethyl ester and EGTA indicated that an increase in Ca(2+) is required for Pyk2 and p130(Cas) tyrosine phosphorylation. Moreover, a complex association was observed between Pyk2, p130(Cas), and paxillin. These results indicate that CD146 is coupled to a FYN-dependent pathway that triggers Ca(2+) flux via phospholipase C-gamma activation leading subsequently to the tyrosine phosphorylation of downstream targets such as Pyk2, p130(Cas), FAK, and paxillin. In addition to its role in cell-cell adhesion, CD146 is a signaling molecule involved in the dynamics of actin cytoskeleton rearrangement.
authors.affiliation: INSERM EMI 00-19 Physiopathologie de l'Endothélium, UFR Pharmacie, Université de la Mediterranée, 13385 Marseille, France. anfosso@pharmacie.univ-mrs.fr
authors.forename: F
authors.initials: F
authors.lastname: Anfosso
authors.forename: N
authors.initials: N
authors.lastname: Bardin
authors.forename: E
authors.initials: E
authors.lastname: Vivier
authors.forename: F
authors.initials: F
authors.lastname: Sabatier
authors.forename: J
authors.initials: J
authors.lastname: Sampol
authors.forename: F
authors.initials: F
authors.lastname: Dignat-George
mesh_terms: D015703:Antigens, CD; D000954:Antigens, Surface / Q000502:physiology*; D016227:Benzoquinones; D051929:CD146 Antigen; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D047029:Lactams, Macrocyclic; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D011809:Quinones / Q000494:pharmacology; D017828:Rifabutin / Q000031:analogs & derivatives; D015398:Signal Transduction / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology; D014471:Umbilical Veins
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D016227:Benzoquinones; D051929:CD146 Antigen; D002614:Chelating Agents; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D047029:Lactams, Macrocyclic; C497902:MCAM protein, human; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D011809:Quinones; D017828:Rifabutin; D004533:Egtazic Acid; D019284:Thapsigargin; C020754:herbimycin; D011505:Protein-Tyrosine Kinases; C494957:FYN protein, human; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D051076:Proto-Oncogene Proteins c-fyn; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium