Roles of Rho/ROCK and MLCK in TNF-alpha-induced changes in endothelial morphology and permeability

J Cell Physiol. 2007 Oct;213(1):221-8. doi: 10.1002/jcp.21114.


Tumor necrosis factor-alpha (TNF-alpha) is known to induce changes in endothelial cell morphology and permeability, but the mechanisms have not been extensively characterized. TNF-alpha rapidly induced RhoA activation and myosin light chain phosphorylation, but caused only small changes to cortical F-actin, without significantly increasing paracellular permeability up to 30 min after stimulation. TNF-alpha subsequently caused a progressive increase in permeability and in stress fiber reorganization, cell elongation, and intercellular gap formation over 8-24 h. Consistent with the increased permeability, Occludin and JAM-A were removed from tight junctions and ZO-1 was partially redistributed. Rho/ROCK but not MLCK inhibition prevented the long-term TNF-alpha-induced changes in F-actin and cell morphology, but ROCK inhibition did not affect permeability. These results suggest that the gradual increase in permeability induced by TNF-alpha does not reflect contractile mechanisms mediated by Rho, ROCK, and MLCK, but involves long-term reorganization of tight junction proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Cell Membrane Permeability / drug effects
  • Cell Shape / drug effects
  • Cells, Cultured
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Membrane Proteins / metabolism
  • Myosin-Light-Chain Kinase / metabolism
  • Myosins / metabolism
  • Occludin
  • Protein Serine-Threonine Kinases / metabolism*
  • Tight Junctions / drug effects
  • Tumor Necrosis Factor-alpha / pharmacology*
  • rho GTP-Binding Proteins / metabolism*
  • rho-Associated Kinases


  • Actins
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • OCLN protein, human
  • Occludin
  • Tumor Necrosis Factor-alpha
  • myosin IXB
  • Protein Serine-Threonine Kinases
  • rho-Associated Kinases
  • Myosin-Light-Chain Kinase
  • Myosins
  • rho GTP-Binding Proteins