Effects of adrenomedullin on endothelial cells in the multistep process of angiogenesis: involvement of CRLR/RAMP2 and CRLR/RAMP3 receptors.
Recently, we demonstrated that U87 glioblastoma xenograft tumors treated with anti-adrenomedullin (AM) antibody were less vascularized than control tumors, suggesting that AM might be involved in neovascularization and/or vessel stabilization. Angiogenesis, the sprouting of new capillaries from preexisting blood vessels, is a multistep process that involves migration and proliferation of endothelial cells, remodeling of the extracellular matrix and functional maturation of the newly assembled vessels. In our study, we analyzed the role of AM on human umbilical vein endothelial cell (HUVEC) phenotype related to different stages of angiogenesis. Here we report evidence that AM promoted HUVEC migration and invasion in a dose-dependent manner. The action of AM is specific and is mediated by the calcitonin receptor-like receptor/receptor activity-modifying protein-2 and -3 (CRLR/RAMP2; CRLR/RAMP3) receptors. Furthermore, AM was able to induce HUVEC differentiation into cord-like structures on Matrigel. Suboptimal concentrations of vascular endothelial growth factor (VEGF) and AM acted synergistically to induce angiogenic-related effects on endothelial cells in vitro. Blocking antibodies to VEGF did not significantly inhibit AM-induced capillary tube formation by human endothelial cells, indicating that AM does not function indirectly through upregulation of VEGF. These findings suggest that the proangiogenic action of AM on cultured endothelial cells via CRLR/RAMP2 and CRLR/RAMP3 receptors may translate in vivo into enhanced neovascularization and therefore identify AM and its receptors acting as potential new targets for antiangiogenic therapies.
Fernandez-Sauze
Samantha
S
Laboratoire de Cancérologie Expérimentale, Inserm EMI 0359, Faculté de Médecine Secteur Nord, IFR Jean Roche, Boulevard Pierre Dramard, Marseille, France.
Delfino
Christine
C
Mabrouk
Kamel
K
Dussert
Christophe
C
Chinot
Olivier
O
Martin
Pierre-Marie
PM
Grisoli
Francois
F
Ouafik
L'Houcine
L
Boudouresque
Françoise
F
D053607:Adrenomedullin; D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D015153:Blotting, Western; D002454:Cell Differentiation; D002455:Cell Division; D045744:Cell Line, Tumor; D002465:Cell Movement; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000502:physiology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007797:Laminin / Q000494:pharmacology; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic; D010455:Peptides / Q000502:physiology*; D010641:Phenotype; D011509:Proteoglycans / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D058263:Receptor Activity-Modifying Protein 2; D058264:Receptor Activity-Modifying Protein 3; D058261:Receptor Activity-Modifying Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014471:Umbilical Veins / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D004338:Drug Combinations; D047908:Intracellular Signaling Peptides and Proteins; D007797:Laminin; D008565:Membrane Proteins; D010455:Peptides; D011509:Proteoglycans; C545503:RAMP2 protein, human; C545504:RAMP3 protein, human; D012333:RNA, Messenger; D058263:Receptor Activity-Modifying Protein 2; D058264:Receptor Activity-Modifying Protein 3; D058261:Receptor Activity-Modifying Proteins; D042461:Vascular Endothelial Growth Factor A; C059485:matrigel; D053607:Adrenomedullin; D003094:Collagen