TY - JOUR
T1 - Talin-Dependent Integrin Activation Regulates VE-Cadherin Localization and Endothelial Cell Barrier Function
AU - Pulous, Fadi E.
AU - Grimsley-Myers, Cynthia M.
AU - Kansal, Shevali
AU - Kowalczyk, Andrew P.
AU - Petrich, Brian G.
N1 - Publisher Copyright:
© 2019 American Heart Association, Inc.
PY - 2019/3/15
Y1 - 2019/3/15
N2 - Rationale: Endothelial barrier function depends on the proper localization and function of the adherens junction protein VE (vascular endothelial)-cadherin. Previous studies have suggested a functional relationship between integrin-mediated adhesion complexes and VE-cadherin yet the underlying molecular links are unclear. Binding of the cytoskeletal adaptor protein talin to the β-integrin cytoplasmic domain is a key final step in regulating the affinity of integrins for extracellular ligands (activation) but the role of integrin activation in VE-cadherin mediated endothelial barrier function is unknown. Objective: To test the requirement of talin-dependent activation of β1 integrin in VE-cadherin organization and endothelial cell (EC) barrier function. Methods and Results: EC-specific deletion of talin in adult mice resulted in impaired stability of intestinal microvascular blood vessels, hemorrhage, and death. Talin-deficient endothelium showed altered VE-cadherin organization at EC junctions in vivo. shRNA (short hairpin RNA)-mediated knockdown of talin1 expression in cultured ECs led to increased radial actin stress fibers, increased adherens junction width and increased endothelial monolayer permeability measured by electrical cell-substrate impedance sensing. Restoring β1-integrin activation in talin-deficient cells with a β1-integrin activating antibody normalized both VE-cadherin organization and EC barrier function. In addition, VE-cadherin organization was normalized by reexpression of talin or integrin activating talin head domain but not a talin head domain mutant that is selectively deficient in activating integrins. Conclusions: Talin-dependent activation of EC β1-integrin stabilizes VE-cadherin at endothelial junctions and promotes endothelial barrier function.
AB - Rationale: Endothelial barrier function depends on the proper localization and function of the adherens junction protein VE (vascular endothelial)-cadherin. Previous studies have suggested a functional relationship between integrin-mediated adhesion complexes and VE-cadherin yet the underlying molecular links are unclear. Binding of the cytoskeletal adaptor protein talin to the β-integrin cytoplasmic domain is a key final step in regulating the affinity of integrins for extracellular ligands (activation) but the role of integrin activation in VE-cadherin mediated endothelial barrier function is unknown. Objective: To test the requirement of talin-dependent activation of β1 integrin in VE-cadherin organization and endothelial cell (EC) barrier function. Methods and Results: EC-specific deletion of talin in adult mice resulted in impaired stability of intestinal microvascular blood vessels, hemorrhage, and death. Talin-deficient endothelium showed altered VE-cadherin organization at EC junctions in vivo. shRNA (short hairpin RNA)-mediated knockdown of talin1 expression in cultured ECs led to increased radial actin stress fibers, increased adherens junction width and increased endothelial monolayer permeability measured by electrical cell-substrate impedance sensing. Restoring β1-integrin activation in talin-deficient cells with a β1-integrin activating antibody normalized both VE-cadherin organization and EC barrier function. In addition, VE-cadherin organization was normalized by reexpression of talin or integrin activating talin head domain but not a talin head domain mutant that is selectively deficient in activating integrins. Conclusions: Talin-dependent activation of EC β1-integrin stabilizes VE-cadherin at endothelial junctions and promotes endothelial barrier function.
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U2 - 10.1161/CIRCRESAHA.118.314560
DO - 10.1161/CIRCRESAHA.118.314560
M3 - Article
C2 - 30707047
AN - SCOPUS:85062979617
SN - 0009-7330
VL - 124
SP - 891
EP - 903
JO - Circulation research
JF - Circulation research
IS - 6
ER -