title: Dehydroepiandrosterone stimulates endothelial proliferation and angiogenesis through extracellular signal-regulated kinase 1/2-mediated mechanisms.
abstract: Dehydroepiandrosterone (DHEA) activates a plasma membrane receptor on vascular endothelial cells and phosphorylates ERK 1/2. We hypothesize that ERK1/2-dependent vascular endothelial proliferation underlies part of the beneficial vascular effect of DHEA. DHEA (0.1-10 nm) activated ERK1/2 in bovine aortic endothelial cells (BAECs) by 15 min, causing nuclear translocation of phosphorylated ERK1/2 and phosphorylation of nuclear p90 ribosomal S6 kinase. ERK1/2 phosphorylation was dependent on plasma membrane-initiated activation of Gi/o proteins and the upstream MAPK kinase because the effect was seen with albumin-conjugated DHEA and was blocked by pertussis toxin or PD098059. A 15-min incubation of BAECs with 1 nm DHEA (or albumin-conjugated DHEA) increased endothelial proliferation by 30% at 24 h. This effect was not altered by inhibition of estrogen or androgen receptors or nitric oxide production. There was a similar effect of DHEA to increase endothelial migration. DHEA also increased the formation of primitive capillary tubes of BAECs in vitro in solubilized basement membrane. These rapid DHEA-induced effects were reversed by the inhibition of either Gi/o-proteins or ERK1/2. Additionally, DHEA enhanced angiogenesis in vivo in a chick embryo chorioallantoic membrane assay. These findings indicate that exposure to DHEA, at concentrations found in human blood, causes vascular endothelial proliferation by a plasma membrane-initiated activity that is Gi/o and ERK1/2 dependent. These data, along with previous findings, define an important vascular endothelial cell signaling pathway that is activated by DHEA and suggest that this steroid may play a role in vascular function.
authors: Division of Endocrinology, Veterans Affairs Medical Center, University of Iowa,Iowa City, Iowa 52242, USA. doliu@vt.edu
authors: Dongmin
authors: D
authors: Liu
authors: Mary
authors: M
authors: Iruthayanathan
authors: Laurie L
authors: LL
authors: Homan
authors: Yiqiang
authors: Y
authors: Wang
authors: Lingling
authors: L
authors: Yang
authors: Yao
authors: Y
authors: Wang
authors: Joseph S
authors: JS
authors: Dillon
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation; D002478:Cells, Cultured; D003687:Dehydroepiandrosterone / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology*; D004789:Enzyme Activation / Q000187:drug effects; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D003687:Dehydroepiandrosterone; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019206:GTP-Binding Protein alpha Subunits, Gi-Go