title: Visfatin as a novel mediator released by inflamed human endothelial cells.
abstract: BACKGROUND
  Visfatin is a multifaceted adipokine whose circulating levels are enhanced in different metabolic diseases. Extracellular visfatin can exert various deleterious effects on vascular cells, including inflammation and proliferation. Limited evidence exists, however, on the capacity of human vascular cells to synthesize and release visfatin by themselves, under basal or pro-inflammatory conditions.
  
  
  RESULTS
  Intracellular visfatin was detected by Western blot in non-stimulated human umbilical vein endothelial cells (HUVEC). However, exposing HUVEC for 18 h to a series of pro-inflammatory stimulus, such as interleukin (IL)-1β (1 to 10 ng/mL), tumor necrosis factor-α (1 to 10 ng/mL) or angiotensin II (10 pmol/L to 1 μmol/L) markedly enhanced intracellular visfatin content. Using IL-1β (10 ng/mL; 18 h), it was determined that the increase in intracellular visfatin, which was paralleled by enhanced visfatin mRNA levels, relied on a signalling mechanism involving both nuclear factor-κB and poly (ADP ribose) polymerase-1 activation. Moreover, IL-1β modified the sub-cellular localization of visfatin; while in non-stimulated HUVEC immunoreactive visfatin predominantly showed an intra-nuclear granular pattern, in IL-1β-inflamed cells an extra-nuclear filamentous staining, co-localising with F-actin fibers and suggesting a secretory pattern, was mainly found. Indeed, IL-1β promoted visfatin secretion, as determined by both ELISA and immunocytochemistry.
  
  
  CONCLUSIONS
  Human endothelial cells synthesize and release visfatin, particularly in response to inflammation. We suggest that the inflamed endothelium can be a source of visfatin, which arises as a local inflammatory mediator and a potential therapeutic target to interfere with vascular inflammation.
authors.affiliation: Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain ; Instituto de Investigación Sanitaria del Hospital de La Princesa, Madrid, Spain.
authors.forename: Tania
authors.initials: T
authors.lastname: Romacho
authors.forename: Laura A
authors.initials: LA
authors.lastname: Villalobos
authors.forename: Elena
authors.initials: E
authors.lastname: Cercas
authors.forename: Raffaele
authors.initials: R
authors.lastname: Carraro
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Sánchez-Ferrer
authors.forename: Concepción
authors.initials: C
authors.lastname: Peiró
mesh_terms: D000804:Angiotensin II / Q000276:immunology; D042783:Endothelial Cells / Q000276:immunology* / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000276:immunology; D053583:Interleukin-1beta / Q000276:immunology; D054409:Nicotinamide Phosphoribosyltransferase / Q000032:analysis / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D053583:Interleukin-1beta; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000804:Angiotensin II; D054409:Nicotinamide Phosphoribosyltransferase