Increased ICAM-1 expression causes endothelial cell leakiness, cytoskeletal reorganization and junctional alterations

J Invest Dermatol. 2007 Apr;127(4):762-74. doi: 10.1038/sj.jid.5700670. Epub 2006 Dec 28.


Tumor necrosis factor (TNF)-induced ICAM-1 in endothelial cells (EC) promotes leukocyte adhesion. Here we report that ICAM-1 also effects EC barrier function. Control- or E-selectin-transduced human dermal microvascular EC (HDMEC) form a barrier to flux of proteins and to passage of current (measured as transendothelial electrical resistance or TEER). HDMEC transduced with ICAM-1 at levels comparable to that induced by TNF show reduced TEER, but do so without overtly changing their cell junctions, cell shape, or cytoskeleton organization. Higher levels of ICAM-1 further reduce TEER, increase F/G-actin ratios, rearrange the actin cytoskeleton to cause cell elongation, and alter junctional zona occludens 1 and vascular endothelial-cadherin staining. Transducing with ICAM-1 lacking an intracellular region also reduces TEER. TNF-induced changes in TEER and shape follow a similar time course as ICAM-1 induction; however, the fall in TEER occurs at lower TNF concentrations. Inhibiting NF-kappaB activation blocks ICAM-1 induction; TEER reduction, and shape change. Specific small-interfering RNA knockdown of ICAM-1 partially inhibits TNF-induced shape change. We conclude that moderately elevated ICAM-1 expression reduces EC barrier function and that expressing higher levels of ICAM-1 affects cell junctions and the cytoskeleton. Induction of ICAM-1 may contribute to but does not fully account for TNF-induced vascular leak and EC shape change.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adherens Junctions / ultrastructure
  • Capillary Permeability / drug effects
  • Capillary Permeability / physiology*
  • Cell Shape / drug effects
  • Cells, Cultured
  • Cytoskeleton / ultrastructure
  • Electric Impedance
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • Endothelial Cells / physiology
  • Humans
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Intercellular Junctions / physiology
  • Microcirculation
  • Skin / blood supply*
  • Tight Junctions / ultrastructure
  • Transduction, Genetic
  • Tumor Necrosis Factor-alpha / pharmacology


  • Tumor Necrosis Factor-alpha
  • Intercellular Adhesion Molecule-1