title: Roles of Rho/ROCK and MLCK in TNF-alpha-induced changes in endothelial morphology and permeability.
abstract: 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.
authors.affiliation: Ludwig Institute for Cancer Research, Royal Free and University College School of Medicine, London, United Kingdom.
authors.forename: Jenny A G
authors.initials: JA
authors.lastname: McKenzie
authors.forename: Anne J
authors.initials: AJ
authors.lastname: Ridley
mesh_terms: D000199:Actins / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D009218:Myosins / Q000378:metabolism; D062793:Occludin; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D019108:Tight Junctions / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D020741:rho GTP-Binding Proteins / Q000378:metabolism*; D054460:rho-Associated Kinases
chemical_list: D000199:Actins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; D014409:Tumor Necrosis Factor-alpha; C113469:myosin IXB; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D009219:Myosin-Light-Chain Kinase; D009218:Myosins; D020741:rho GTP-Binding Proteins