title: A global proteome approach in uric acid stimulated human aortic endothelial cells revealed regulation of multiple major cellular pathways.
abstract: BACKGROUND
  Uric acid (UA) has been identified as one major risk factor for cardiovascular diseases. Lowering of serum UA levels improves endothelial function. The present study investigates for the first time concentration-dependent effects of UA on human aortic endothelial cells (HAEC) and the cellular pathways involved in global proteomic analysis.
  
  
  METHODS
  The concentration dependent effects of UA on HAEC were investigated by nanoLC-MS/MS and ingenuity pathway analysis to reveal putative cellular pathways. For verification of the identified pathways the abundance or activity of key proteins was measured using ELISA or Western blotting. NO production was quantified by confocal laser microscopy.
  
  
  RESULTS
  We identified ubiquitin-proteasome system (UPS) and eIF4 signaling as the major pathways regulated by UA. K-means clustering analysis revealed 11 additional pathways, of which NO, superoxide signaling and hypoxia were further analyzed. A complex regulatory network was detected demonstrating that 500μmol/L UA, which is well above the concentration regarded as pathological in clinical settings, led to diminishing of NO bioavailability. In addition a UA-dependent downregulation of eIF4, an upregulation of UPS and an increase in HIF-1α were detected.
  
  
  CONCLUSIONS
  Here we show for the first time, that increasing UA levels activate different sets of proteins representing specific cellular pathways important for endothelial function. This indicates that UA may alter far more pathways in HAEC than previously assumed. This regulation occurs in a complex manner depending on UA concentration. Further studies in knockout and overexpression models of the identified proteins are necessary to prove the correlation with endothelial dysfunction.
authors.affiliation: Department of Cardiac Surgery, Heart Center Leipzig, University of Leipzig, Leipzig, Germany; Department of Health Sciences/Public Health, University of Dresden, Dresden, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Oberbach
authors.affiliation: Department of Urology, University of Leipzig, Leipzig, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Neuhaus
authors.affiliation: Ernst-Moritz-Arndt-University Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Germany; Helmholtz Centre for Environmental Research, Department of Proteomics, Leipzig, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Jehmlich
authors.affiliation: Department of Pediatric Surgery, University of Leipzig, Leipzig, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Schlichting
authors.affiliation: Department of Cardiac Surgery, Heart Center Leipzig, University of Leipzig, Leipzig, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Heinrich
authors.affiliation: Department of Cardiac Surgery, Heart Center Leipzig, University of Leipzig, Leipzig, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Kullnick
authors.affiliation: Department of Cardiac Surgery, Heart Center Leipzig, University of Leipzig, Leipzig, Germany.
authors.forename: Friedrich-Wilhelm
authors.initials: FW
authors.lastname: Mohr
authors.affiliation: Department of Health Sciences/Public Health, University of Dresden, Dresden, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kugler
authors.affiliation: Helmholtz Centre for Environmental Research, Department of Metabolomics, Leipzig, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Baumann
authors.affiliation: Ernst-Moritz-Arndt-University Greifswald, Interfaculty Institute of Genetics and Functional Genomics, Department of Functional Genomics, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Völker
authors.affiliation: Department of Cardiology, University of Leipzig, Heart Center Leipzig, Leipzig, Germany. Electronic address: adav@medizin.uni-leipzig.de.
authors.forename: Volker
authors.initials: V
authors.lastname: Adams
mesh_terms: D001011:Aorta / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D006801:Humans; D020543:Proteome / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D014527:Uric Acid / Q000494:pharmacology*
chemical_list: D020543:Proteome; D014527:Uric Acid
keywords: Cardiovascular disease; Eukaryotic initiation factor 4F (eIF4); Global proteome approach (2D-nano LC–MS/MS); Hypoxia-inducible factor 1-alpha (HIF-1α); Ubiquitin–proteasome pathway; Uric acid