Oxytocin stimulates in vitro angiogenesis via a Pyk-2/Src-dependent mechanism.
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.
Cattaneo
Maria Grazia
MG
Department of Pharmacology, Università degli Studi di Milano, Via Vanvitelli 32, 20129 Milano, Italy.
Lucci
Gina
G
Vicentini
Lucia M
LM
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
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