title: High density lipoprotein-associated sphingosine 1-phosphate promotes endothelial barrier function.
abstract: High density lipoproteins (HDL) are major plasma carriers of sphingosine 1-phosphate (S1P). Here we show that HDL increases endothelial barrier integrity as measured by electric cell substrate impedance sensing. S1P was implicated as the mediator in this process through findings showing that pertussis toxin, an inhibitor of Gi-coupled S1P receptors, as well as antagonists of the S1P receptor, S1P1, inhibited barrier enhancement by HDL. Additional findings show that HDL stimulates endothelial cell activation of Erk1/2 and Akt, signaling pathway intermediates that have been implicated in S1P-dependent endothelial barrier activity. HDL was also found to promote endothelial cell motility, a process that may also relate to endothelial barrier function in the context of a vascular injury response. The effects of HDL on endothelial cell Erk1/2 and Akt activation and motility were suppressed by pertussis toxin and S1P1 antagonists. However, both HDL-induced barrier enhancement and HDL-induced motility showed a greater dependence on Akt activation as compared with Erk1/2 activation. Together, the findings indicate that HDL has endothelial barrier promoting activities, which are attributable to its S1P component and signaling through the S1P1/Akt pathway.
authors.affiliation: Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, South Carolina 29425, USA. argravek@musc.edu
authors.forename: Kelley M
authors.initials: KM
authors.lastname: Argraves
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Gazzolo
authors.forename: Eric M
authors.initials: EM
authors.lastname: Groh
authors.forename: Brent A
authors.initials: BA
authors.lastname: Wilkerson
authors.forename: Bryan S
authors.initials: BS
authors.lastname: Matsuura
authors.forename: Waleed O
authors.initials: WO
authors.lastname: Twal
authors.forename: Samar M
authors.initials: SM
authors.lastname: Hammad
authors.forename: W Scott
authors.initials: WS
authors.lastname: Argraves
mesh_terms: D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism* / Q000494:pharmacology; D008246:Lysophospholipids / Q000378:metabolism* / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D049349:Receptors, Lysosphingolipid / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D008075:Lipoproteins, HDL; D008246:Lysophospholipids; D049349:Receptors, Lysosphingolipid; C060506:sphingosine 1-phosphate; D037342:Pertussis Toxin; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D013110:Sphingosine