title: Signal transduction pathway in endothelial dysfunction.
abstract: BACKGROUND
  Endothelial dysfunction is an important feature of sepsis, acute respiratory distress syndrome (ARDS), and other infectious conditions. Previously, we reported an in vitro model to study endothelial dysfunction, in which endothelial cells are induced to form capillary tube networks by culturing on a basement membrane matrix (Matrigel). In this study, we defined the signal transduction pathways that lead to endothelial cell function and capillary disruption characteristic of sepsis and other infectious conditions.
  
  
  METHODS
  Human aortic endothelial cells (HAEC) were cultured on a laminin-rich matrix to form capillary-like networks. The HAECs were treated with a protein tyrosine phosphatase inhibitor (sodium orthovanadate), a phosphoinositon-3-phosphate inhibitor (wortmannin), or a protein kinase C inhibitor (bisindolylmaleimide) before capillary tubes had formed or after the capillary tubes had matured. The degree of capillary tube formation was quantified by counting the intersection of capillary networks in triplicate wells. Statistical significance was determined by analysis of variance.
  
  
  RESULTS
  Endothelial dysfunction occurred after inhibition of protein tyrosine phosphatase or protein kinase C. Whereas inhibition of phosphoinositon-3-phosphate did not cause endothelial dysfunction, sodium orthovanadate (2-20 microM) and bisindolylmaleimide (2-10 microM) significantly reduced capillary networks. The mean +/- SD of the number of capillary tubes in the control, sodium orthovanadate-treated, and bisindolylmaleimide-treated groups were 251.0 +/- 7.0, 65.6 +/- 9.9 (p < 0.001), and 181.7 +/- 0.1 (p < 0.001), respectively. Sodium orthovanadate (20-200 microM) and bisindolylmaleimide (10-100 microM) inhibited capillary tube formation. At higher concentrations, sodium orthovanadate (> 200 microM) and bisindolylmaleimide (>100 microM) disrupted mature capillary tubes.
  
  
  CONCLUSIONS
  Our results suggest that PKC and protein tyrosine phosphatase play a role in endothelial dysfunction by interfering with the phosphorylation signals within endothelial cells. These mechanisms may be important in the endothelial dysfunction in sepsis and other infectious conditions.
authors.affiliation: Department of Surgery, SUNY Upstate Medical University, Syracuse, New York 13210, USA.
authors.forename: Chumpon
authors.initials: C
authors.lastname: Wilasrusmee
authors.forename: Gaurang
authors.initials: G
authors.lastname: Shah
authors.forename: Smita
authors.initials: S
authors.lastname: Kittur
authors.forename: Anne
authors.initials: A
authors.lastname: Halverson
authors.forename: David
authors.initials: D
authors.lastname: Bruch
authors.forename: Dilip
authors.initials: D
authors.lastname: Kittur
mesh_terms: D000704:Analysis of Variance; D000730:Androstadienes / Q000494:pharmacology; D002196:Capillaries / Q000502:physiology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008833:Microcirculation / Q000502:physiology; D011336:Probability; D011493:Protein Kinase C / Q000032:analysis / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000032:analysis / Q000378:metabolism*; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology*; D014638:Vanadates / Q000494:pharmacology; D014652:Vascular Diseases / Q000503:physiopathology; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D007211:Indoles; D008301:Maleimides; D014638:Vanadates; D011493:Protein Kinase C; D017027:Protein Tyrosine Phosphatases; C088060:bisindolylmaleimide; D000077191:Wortmannin