title: Sphingosine 1-phosphate is a ligand for peroxisome proliferator-activated receptor-γ that regulates neoangiogenesis.
abstract: Sphingosine 1-phosphate (S1P) is a bioactive lipid that can function both extracellularly and intracellularly to mediate a variety of cellular processes. Using lipid affinity matrices and a radiolabeled lipid binding assay, we reveal that S1P directly interacts with the transcription factor peroxisome proliferator-activated receptor (PPAR)γ. Herein, we show that S1P treatment of human endothelial cells (ECs) activated a luciferase-tagged PPARγ-specific gene reporter by ∼12-fold, independent of the S1P receptors. More specifically, in silico docking, gene reporter, and binding assays revealed that His323 of the PPARγ ligand binding domain is important for binding to S1P. PPARγ functions when associated with coregulatory proteins, and herein we identify that peroxisome proliferator-activated receptor-γ coactivator 1 (PGC1)β binds to PPARγ in ECs and their progenitors (nonadherent endothelial forming cells) and that the formation of this PPARγ:PGC1β complex is increased in response to S1P. ECs treated with S1P selectively regulated known PPARγ target genes with PGC1β and plasminogen-activated inhibitor-1 being increased, no change to adipocyte fatty acid binding protein 2 and suppression of CD36. S1P-induced in vitro tube formation was significantly attenuated in the presence of the PPARγ antagonist GW9662, and in vivo application of GW9662 also reduced vascular development in Matrigel plugs. Interestingly, activation of PPARγ by the synthetic ligand troglitazone also reduced tube formation in vitro and in vivo. To support this, Sphk1(-/-)Sphk2(+/-) mice, with low circulating S1P levels, demonstrated a similar reduction in vascular development. Taken together, our data reveal that the transcription factor, PPARγ, is a bona fide intracellular target for S1P and thus suggest that the S1P:PPARγ:PGC1β complex may be a useful target to manipulate neovascularization.
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Kate A
authors.initials: KA
authors.lastname: Parham
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Zebol
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Tooley
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Wai Y
authors.initials: WY
authors.lastname: Sun
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Lachlan M
authors.initials: LM
authors.lastname: Moldenhauer
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Michaelia P
authors.initials: MP
authors.lastname: Cockshell
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Briony L
authors.initials: BL
authors.lastname: Gliddon
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Moretti
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Gabor
authors.initials: G
authors.lastname: Tigyi
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA.
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Pitson
authors.affiliation: *Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; School of Medicine, University of Adelaide, Adelaide, South Australia, Australia; Co-operative Research Centre for Biomarker Translation, La Trobe University, Melbourne, Victoria, Australia; and Department of Physiology, The University of Tennessee Health Science Center, Memphis, Tennessee, USA claudine.bonder@unisa.edu.au.
authors.forename: Claudine S
authors.initials: CS
authors.lastname: Bonder
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008246:Lysophospholipids / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D018919:Neovascularization, Physiologic / Q000502:physiology*; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins; D049349:Receptors, Lysosphingolipid / Q000235:genetics / Q000378:metabolism*; D058258:Serpin E2 / Q000235:genetics / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D020298:U937 Cells; D000099157:Sphingosine Kinase
chemical_list: D018955:CD36 Antigens; D002352:Carrier Proteins; D008246:Lysophospholipids; D047495:PPAR gamma; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D017853:Phosphotransferases (Alcohol Group Acceptor); D017395:Plasminogen Activator Inhibitor 1; D016601:RNA-Binding Proteins; D049349:Receptors, Lysosphingolipid; D058258:Serpin E2; D013110:Sphingosine; D014157:Transcription Factors; D000099157:Sphingosine Kinase; C455622:PPARGC1B protein, human; C485290:Ppargc1a protein, mouse; C051321:SERPINE1 protein, human; C511869:Serpine2 protein, mouse; C060506:sphingosine 1-phosphate; C000594250:sphingosine kinase 2, human
keywords: endothelial; neovascularization; transcription factor