ZFIN ID: ZDB-PUB-151230-1
Plasminogen Activator Inhibitor-1 Controls Vascular Integrity by Regulating VE-Cadherin Trafficking
Daniel, A.E., Timmerman, I., Kovacevic, I., Hordijk, P.L., Adriaanse, L., Paatero, I., Belting, H.G., van Buul, J.D.
Date: 2015
Source: PLoS One   10: e0145684 (Journal)
Registered Authors: Belting, Heinz-Georg Paul (Henry)
Keywords: Endothelial cells, Zebrafish, Fluorescence recovery after photobleaching, Embryos, Vascular permeability, Catenins, Immunoprecipitation, Golgi apparatus
MeSH Terms:
  • Animals
  • Cadherins/metabolism*
  • Endothelium, Vascular/drug effects
  • Endothelium, Vascular/metabolism*
  • Human Umbilical Vein Endothelial Cells/cytology
  • Human Umbilical Vein Endothelial Cells/drug effects
  • Human Umbilical Vein Endothelial Cells/metabolism
  • Humans
  • Indoleacetic Acids/pharmacology
  • Intercellular Junctions/drug effects
  • Plasminogen Activator Inhibitor 1/metabolism*
  • Protein Transport/drug effects
  • Zebrafish
PubMed: 26714278 Full text @ PLoS One
Plasminogen activator inhibitor-1 (PAI-1), a serine protease inhibitor, is expressed and secreted by endothelial cells. Patients with PAI-1 deficiency show a mild to moderate bleeding diathesis, which has been exclusively ascribed to the function of PAI-1 in down-regulating fibrinolysis. We tested the hypothesis that PAI-1 function plays a direct role in controlling vascular integrity and permeability by keeping endothelial cell-cell junctions intact.
We utilized PAI-039, a specific small molecule inhibitor of PAI-1, to investigate the role of PAI-1 in protecting endothelial integrity. In vivo inhibition of PAI-1 resulted in vascular leakage from intersegmental vessels and in the hindbrain of zebrafish embryos. In addition PAI-1 inhibition in human umbilical vein endothelial cell (HUVEC) monolayers leads to a marked decrease of transendothelial resistance and disrupted endothelial junctions. The total level of the endothelial junction regulator VE-cadherin was reduced, whereas surface VE-cadherin expression was unaltered. Moreover, PAI-1 inhibition reduced the shedding of VE-cadherin. Finally, we detected an accumulation of VE-cadherin at the Golgi apparatus.
Our findings indicate that PAI-1 function is important for the maintenance of endothelial monolayer and vascular integrity by controlling VE-cadherin trafficking to and from the plasma membrane. Our data further suggest that therapies using PAI-1 antagonists like PAI-039 ought to be used with caution to avoid disruption of the vessel wall.