title: Reduced expression of adipose triglyceride lipase decreases arachidonic acid release and prostacyclin secretion in human aortic endothelial cells.
abstract: BACKGROUND
  Vascular endothelial cells represent an important source of arachidonic acid (AA)-derived mediators involved in the generation of anti- or proatherogenic environments. Evidence emerged (in mast cells), that in addition to phospholipases, neutral lipid hydrolases as adipose triglyceride lipase (ATGL) also participate in this process.
  
  
  OBJECTIVE
  To examine the impact of ATGL on AA-release from cellular phospholipids (PL) and on prostacyclin secretion in human aortic endothelial cells (HAEC).
  
  
  RESULTS
  siRNA-mediated silencing of ATGL promoted lipid droplet formation and TG accumulation in HAEC (nile red stain). ATGL knockdown decreased the basal and A23187 (calcium ionophore)-induced release of14C-AA from (14C-AA-labeled) HAEC. In A23187-stimulated ATGL silenced cells, this was accompanied by a decreased content of14C-AA in cellular PL and a decreased secretion of prostacyclin (determined by 6-keto PGF1α EIA).
  
  
  CONCLUSIONS
  In vascular endothelial cells, the efficiency of stimulus-induced AA release and prostacyclin secretion is dependent on ATGL.
authors.affiliation: a Institute of Molecular Biology and Biochemistry , Center of Molecular Medicine , Graz , Austria.|b Institute of Biomedical Science , University of Applied Sciences , Graz , Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Riederer
authors.affiliation: a Institute of Molecular Biology and Biochemistry , Center of Molecular Medicine , Graz , Austria.
authors.forename: Margarete
authors.initials: M
authors.lastname: Lechleitner
authors.affiliation: c Center for Medical Research, Core Facility Mass Spectrometry , Medical University Graz , Graz , Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Köfeler
authors.affiliation: a Institute of Molecular Biology and Biochemistry , Center of Molecular Medicine , Graz , Austria.
authors.forename: Saša
authors.initials: S
authors.lastname: Frank
mesh_terms: D001011:Aorta / Q000166:cytology / Q000378:metabolism*; D016718:Arachidonic Acid / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D011464:Epoprostenol / Q000378:metabolism*; D006801:Humans; D008049:Lipase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D000217:Acyltransferases
chemical_list: D016718:Arachidonic Acid; D011464:Epoprostenol; D008049:Lipase; D034741:RNA, Small Interfering; C494794:PNPLA2 protein, human; D000217:Acyltransferases
keywords: Arachidonic acid; adipose triglyceride lipase; eicosanoids; phospholipase