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Src Family Kinases collaborate with distinct TNF‐alpha‐induced signaling pathways to regulate actin dynamics at cell‐cell junctions and barrier function in endothelial cells
Author(s) -
Adam Alejandro Pablo,
Lowery Anthony,
Vincent Peter
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1063.2
Subject(s) - microbiology and biotechnology , adherens junction , cortactin , proto oncogene tyrosine protein kinase src , cofilin , actin cytoskeleton , focal adhesion , src family kinase , chemistry , kinase , actin , tyrosine protein kinase csk , phosphorylation , cytoskeleton , biology , sh3 domain , cell , cadherin , biochemistry
We previously showed that activation of Src Family Kinases (SFK) by expression of dominant negative C‐terminal Src Kinase (DN‐CSK) is not sufficient to decrease endothelial AJ integrity. However, SFK activation by expression DN‐CSK results in the formation of very dynamic lamellae that show a distinct reticular pattern of adherens junction (AJ) proteins, localization of cortactin at the leading edge of the lamellae and activation of SFK at the cell‐cell junctions. DN‐Csk also induced β3 integrin activation and phosphorylation at the AJ. TIRF live imaging showed actin polymerization preceding AJ formation at the borders of lamellae in close contact with the extracellular matrix. Interestingly, low doses of TNF‐α that do not decrease TEER or cortical actin in control cells did produce a decrease in TEER in cells expressing DN‐Csk, together with a loss in the cortical actin band and the formation of short, thick bundles of actin. These actin changes were prevented by inhibition of ROCK activity or β3 integrin binding, even though TEER was still decreased. Preliminary data show that TEER decrease can be prevented by inhibiting p38 activity. These results suggest that the loss of endothelial barrier function induced by TNF‐α and SFK activation utilizes a p38‐dependent pathway, while a β3 integrin‐ and Rho‐ROCK‐dependent pathway is required for the cytoskeletal changes. Supported by NHLB‐HL077870.