Regulation of endothelial nitric oxide synthase activation in endothelial cells by S1P1 and S1P3.
Endothelial nitric oxide synthase (eNOS) plays a crucial role in vascular homeostasis. Lysophospholipid interaction with sphingosine 1-phosphat (S1P) receptors results in eNOS activation in different cells. In endothelial cells, eNOS activation via S1P1 or S1P3 was shown controversially. The aim of this study is to investigate the meaning of both S1P receptors for eNOS activation in human endothelial cells. Therefore, several S1P1 and S1P3 agonists in combination with antagonists and specific RNAi approach were used. eNOS activation was measured in human umbilical vein endothelial cells (HUVEC) via DAF2-DA-based fluorescence microscopy. For investigation of the signaling pathway, agonists/antagonist studies, RNAi approach, Luminex™ multiplex, and Western Blot were used. In HUVEC, both the S1P1 agonist AUY954 as well as the S1P1,3 agonist FTY720P induced eNOS activation in a time- and dose-dependent manner. Other S1P1 agonists activated eNOS to a lesser extent. The AUY954-induced eNOS activation was blocked by the S1P1 antagonist W146, the combination of W146 and the S1P3 antagonist CAY10444 and the S1P1,3 antagonist VPC23019, but not by CAY10444 indicating the meaning of S1P1 for the AUY954-induced eNOS activation. The FTY720P-induced eNOS activation was blocked only by the combination of W146 and CAY10444 and the combined S1P1,3 antagonist VPC23019, but not by W146 or CAY10444 indicating the importance of both S1P1 and S1P3 for FTY720-induced eNOS activation. These results were confirmed using specific siRNA against S1P1 and S1P3. The S1P1,3 activation results in Akt phosphorylation and subsequent activation of eNOS via phosphorylation at serine(1177) and dephosphorylation at threonine(495). Beside former investigations with rather unspecific S1P receptor activation these data show potent selective S1P1 activation by using AUY954 and with selective S1P receptor inhibition evidence was provided that both S1P1 and S1P3 lead to downstream activation of eNOS in HUVEC in the same experimental setting. Inhibition or knockdown of one of these receptor subtypes did not abolish the eNOS activation and subsequent NO production.
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany. Electronic address: Markus.Toelle@charite.de.
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Tölle
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
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Klöckl
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
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Wiedon
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
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Zidek
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
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van der Giet
Charité - Universitaetsmedizin Berlin, CharitéCentrum 13, Department of Nephrology, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin, Germany.
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Schuchardt
D000813:Anilides / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D009569:Nitric Oxide / Q000096:biosynthesis; D052250:Nitric Oxide Synthase Type III / Q000737:chemistry / Q000378:metabolism*; D010755:Organophosphates / Q000494:pharmacology; D063065:Organophosphonates / Q000494:pharmacology; D010766:Phosphorylation; D010768:Phosphoserine / Q000031:analogs & derivatives / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D049349:Receptors, Lysosphingolipid / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000081025:Sphingosine-1-Phosphate Receptors; D053778:Thiazolidines / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D015091:beta-Alanine / Q000031:analogs & derivatives / Q000494:pharmacology
C513113:3-amino-4-(3-hexylphenylamino)-4-oxobutylphosphonic acid; C517408:AUY 954; D000813:Anilides; C000609617:CAY10444; C525008:FTY 720P; D010755:Organophosphates; D063065:Organophosphonates; D034741:RNA, Small Interfering; D049349:Receptors, Lysosphingolipid; C477362:S1PR1 protein, human; D000081025:Sphingosine-1-Phosphate Receptors; D053778:Thiazolidines; D013876:Thiophenes; C000611541:VPC23019; C577483:sphingosine-1-phosphate receptor-3, human; D015091:beta-Alanine; D010768:Phosphoserine; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt; D013110:Sphingosine
AUY954; Endothelial nitric oxide synthesis; FTY720P; Nitric oxide; S1P receptor; Sphingosine 1-phosphate