Involvement of endothelial nitric oxide in sphingosine-1-phosphate-induced angiogenesis.
Nitric oxide (NO) has been implicated as a critical signaling molecule of angiogenesis. Recently, sphingosine-1-phosphate (S1P) has emerged as a mediator of angiogenesis, and S1P-induced NO synthesis in endothelial cells (ECs) has been reported. To analyze the signaling pathways involved in S1P-induced angiogenesis and clarify the role of NO in this process, we performed in vivo and in vitro angiogenesis assays. S1P activated the phosphatidylinositol-3-kinase (PI3K)/Akt/endothelial NO synthase (eNOS) pathway in ECs, since S1P-stimulated eNOS phosphorylation and NO production were blocked by inhibition of activities of PI3K and Akt. S1P increased capillary ingrowth into subcutaneously implanted Matrigel plugs in mice, and the effect of S1P was significantly reduced in mice that received N(G)-nitro- L-arginine methyl ester (L-NAME), an inhibitor of NOS. S1P stimulated EC migration and tube formation on Matrigel, which processes were significantly decreased by inhibition of activities of PI3K, Akt, or eNOS, whereas treatment with LY294002, a PI3K inhibitor, but not L-NAME, inhibited EC viability and proliferation. Thus, our results demonstrate the crucial role of NO in S1P-induced angiogenesis in vivo and in vitro and suggest the divergent roles of NO in the S1P-induced angiogenic response.
Rikitake
Yoshiyuki
Y
Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan. rikitake@med.kobe-u.ac.jp
Hirata
Ken-ichi
K
Kawashima
Seinosuke
S
Ozaki
Masanori
M
Takahashi
Tomosaburo
T
Ogawa
Wataru
W
Inoue
Nobutaka
N
Yokoyama
Mitsuhiro
M
D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D003094:Collagen; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000201:enzymology / Q000502:physiology*; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007797:Laminin; D008246:Lysophospholipids; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000502:physiology*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D011509:Proteoglycans; D015398:Signal Transduction / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology*
D001672:Biocompatible Materials; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D007797:Laminin; D008246:Lysophospholipids; D011509:Proteoglycans; C059485:matrigel; C060506:sphingosine 1-phosphate; D009569:Nitric Oxide; D003094:Collagen; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse; D019869:Phosphatidylinositol 3-Kinases; D013110:Sphingosine; D019331:NG-Nitroarginine Methyl Ester