title: Differential intracellular calcium influx, nitric oxide production, ICAM-1 and IL8 expression in primary bovine endothelial cells exposed to nonesterified fatty acids.
abstract: BACKGROUND
  Nonesterified fatty acids (NEFAs) are involved in proinflammatory processes in cattle, including in the increased expression of adhesion molecules in endothelial cells. However, the mechanisms underlying these effects are still unknown. The aim of this study was to assess the effects of NEFAs on the intracellular calcium (Ca(2+) i) influx, nitric oxide production, and ICAM-1 and IL-8 expression in primary bovine umbilical vein endothelial cells (BUVECs).
  
  
  RESULTS
  Myristic (MA), palmitic (PA), stearic (SA), oleic (OA) and linoleic acid (LA) rapidly increased Ca(2+) i. The calcium response to all tested NEFAs showed an extracellular calcium dependence and only the LA response was significantly inhibited until the intracellular calcium was chelated. The EC50 values for MA and LA were 125 μM and 37 μM, respectively, and the MA and LA effects were dependent on calcium release from the endoplasmic reticulum stores and on the L-type calcium channels. Only the calcium response to MA was significantly reduced by GW1100, a selective G-protein-coupled free fatty acid receptor (GPR40) antagonist. We also detected a functional FFAR1/GPR40 protein in BUVECs by using western blotting and the FFAR1/GPR40 agonist TAK-875. Only LA increased the cellular nitric oxide levels in a calcium-dependent manner. LA stimulation but not MA stimulation increased ICAM-1 and IL-8-expression in BUVECs. This effect was inhibited by GW1100, an antagonist of FFAR1/GPR40, but not by U-73122, a phospholipase C inhibitor.
  
  
  CONCLUSIONS
  These findings strongly suggest that each individual NEFA stimulates endothelial cells in a different way, with clearly different effects on intracellular calcium mobilization, NO production, and IL-8 and ICAM-1 expression in primary BUVECs. These findings not only extend our understanding of NEFA-mediated diseases in ruminants, but also provide new insight into the different molecular mechanisms involved during endothelial cell activation by NEFAs.
authors.affiliation: Instituto de Farmacología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Anitsi
authors.initials: A
authors.lastname: Loaiza
authors.affiliation: Instituto de Farmacología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: María D
authors.initials: MD
authors.lastname: Carretta
authors.affiliation: Institute of Parasitology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Taubert
authors.affiliation: Institute of Parasitology, Faculty of Veterinary Medicine, Justus Liebig University Giessen, Giessen, Germany.
authors.forename: Carlos
authors.initials: C
authors.lastname: Hermosilla
authors.affiliation: Instituto de Farmacología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: María A
authors.initials: MA
authors.lastname: Hidalgo
authors.affiliation: Instituto de Farmacología, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile. rburgos1@uach.cl.
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Burgos
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002470:Cell Survival; D042783:Endothelial Cells / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000494:pharmacology*; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D009569:Nitric Oxide / Q000096:biosynthesis
chemical_list: D005230:Fatty Acids, Nonesterified; D016209:Interleukin-8; D018799:Intercellular Adhesion Molecule-1; D009569:Nitric Oxide; D002118:Calcium