Src Family Kinases Modulate the Loss of Endothelial Barrier Function in Response to TNF-α: Crosstalk with p38 Signaling.
Activation of Src Family Kinase (SFK) signaling is required for the increase in endothelial permeability induced by a variety of cytokines and growth factors. However, we previously demonstrated that activation of endogenous SFKs by expression of dominant negative C-terminal Src Kinase (DN-Csk) is not sufficient to decrease endothelial adherens junction integrity. Basal SFK activity has been observed in normal venular endothelia and was not associated with increased basal permeability. The basal SFK activity however was found to contribute to increased sensitivity of the venular endothelium to inflammatory mediator-induced leakage. How SFK activation achieves this is still not well understood. Here, we show that SFK activation renders human dermal microvascular endothelial cells susceptible to low doses of TNF-α. Treatment of DN-Csk-expressing cells with 50 pg/ml TNF-α induced a loss of TEER as well as drastic changes in the actin cytoskeleton and focal adhesion proteins. This synergistic effect was independent of ROCK or NF-κB activity. TNF-α-induced p38 signaling was required for the synergistic effect on barrier function, and activation of the p38 MAPK alone was also able to induce changes in permeability only in monolayers with active SFKs. These results suggest that the activation of endogenous levels of SFK renders the endothelial barrier more susceptible to low, physiologic doses of TNF-α through activation of p38 which leads to a loss of endothelial tight junctions.
Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, United States of America.|Department of Ophthalmology, Albany Medical College, Albany, New York, United States of America.
Alejandro P
http://orcid.org/0000-0001-6285-7235
AP
Adam
Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, United States of America.
Anthony M
AM
Lowery
Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, United States of America.
Nina
N
Martino
Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, United States of America.
Hiba
H
Alsaffar
Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York, United States of America.
Peter A
PA
Vincent
D022005:Adherens Junctions / Q000187:drug effects; D000081247:CSK Tyrosine-Protein Kinase; D002448:Cell Adhesion / Q000187:drug effects* / Q000235:genetics; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D016328:NF-kappa B / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D019108:Tight Junctions / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism* / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000235:genetics*; D019061:src-Family Kinases / Q000096:biosynthesis / Q000235:genetics*
D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D048051:p38 Mitogen-Activated Protein Kinases