title: Oxytocin stimulates in vitro angiogenesis via a Pyk-2/Src-dependent mechanism.
abstract: We previously reported that the hypothalamic hormone oxytocin (OT), best known for its uterotonic activity, also stimulates migration and invasion in human umbilical vein endothelial cells (HUVECs), thus suggesting a possible role for the peptide in the regulation of angiogenesis. We identified the Gq coupling of OT receptors (OTRs) and phospholipase C (PLC) as the main effectors of OT's action in HUVECs. Moreover, the pro-migratory effect of OT required the OTR-induced activation of the phosphatidylinositol-3-kinase (PI-3-K)/AKT/endothelial nitric oxide synthase (eNOS) pathway. To better characterize the proposed pro-angiogenic effect of OT in HUVECs, we have now utilized a three-dimensional (3-D) in vitro angiogenesis assay, and demonstrated that OT stimulates the outgrowth of capillary-like structures from HUVEC spheroids to an extent comparable to that of vascular endothelial growth factor (VEGF). This OT effect was abolished by inhibitors of PLC, PI-3-K and Src kinase. It was also found that OT phosphorylates proline-rich tyrosine kinase-2 (Pyk-2) and Src kinase in a PLC- and calcium-dependent manner. Furthermore, knockdown of Pyk-2 expression by RNA interference markedly impaired Src phosphorylation, migration and endothelial cell sprouting induced by OT. In conclusion, by using a pharmacological and genetic approach, the OT pro-angiogenic action and the cascade of intracellular signals responsible for it were defined by showing for the first time that OT, by interacting with its Gq-coupled receptor, induces HUVEC capillary outgrowth via Pyk-2 phosphorylation, which activates Src which in turn activates the PI-3-K/AKT pathway.
authors: Department of Pharmacology, Università degli Studi di Milano, Via Vanvitelli 32, 20129 Milano, Italy.
authors: Maria Grazia
authors: MG
authors: Cattaneo
authors: Gina
authors: G
authors: Lucci
authors: Lucia M
authors: LM
authors: Vicentini
mesh_terms: D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D051418:Focal Adhesion Kinase 2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D018919:Neovascularization, Physiologic; D010121:Oxytocin / Q000494:pharmacology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000378:metabolism; D018045:Receptors, Oxytocin / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000099157:Sphingosine Kinase
chemical_list: D002867:Chromones; D004791:Enzyme Inhibitors; D004963:Estrenes; D051418:Focal Adhesion Kinase 2; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D009025:Morpholines; D010121:Oxytocin; D019869:Phosphatidylinositol 3-Kinases; D010726:Phosphodiesterase Inhibitors; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017853:Phosphotransferases (Alcohol Group Acceptor); D051057:Proto-Oncogene Proteins c-akt; D011743:Pyrimidines; D011760:Pyrrolidinones; D034741:RNA, Small Interfering; D018045:Receptors, Oxytocin; D013110:Sphingosine; D010738:Type C Phospholipases; D042461:Vascular Endothelial Growth Factor A; D019061:src-Family Kinases; D000099157:Sphingosine Kinase; C412373:AG 1879; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C061800:N,N-dimethylsphingosine