scholarly journals p120-Catenin regulates leukocyte transmigration through an effect on VE-cadherin phosphorylation

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2770-2779 ◽  
Author(s):  
Pilar Alcaide ◽  
Gail Newton ◽  
Scott Auerbach ◽  
Seema Sehrawat ◽  
Tanya N. Mayadas ◽  
...  
Keyword(s):  
Surface Expression ◽  
Vascular Endothelial ◽  
Gap Formation ◽  
P120 Catenin ◽  
Leukocyte Transmigration ◽  
Vascular Endothelial Cadherin ◽  
Leukocyte Transendothelial Migration ◽  
Endothelial Junctions ◽  
Functional Consequences ◽  
Time Required

Abstract Vascular endothelial–cadherin (VE-cad) is localized to adherens junctions at endothelial cell borders and forms a complex with α-, β-, γ-, and p120-catenins (p120). We previously showed that the VE-cad complex disassociates to form short-lived “gaps” during leukocyte transendothelial migration (TEM); however, whether these gaps are required for leukocyte TEM is not clear. Recently p120 has been shown to control VE-cad surface expression through endocytosis. We hypothesized that p120 regulates VE-cad surface expression, which would in turn have functional consequences for leukocyte transmigration. Here we show that endothelial cells transduced with an adenovirus expressing p120GFP fusion protein significantly increase VE-cad expression. Moreover, endothelial junctions with high p120GFP expression largely prevent VE-cad gap formation and neutrophil leukocyte TEM; if TEM occurs, the length of time required is prolonged. We find no evidence that VE-cad endocytosis plays a role in VE-cad gap formation and instead show that this process is regulated by changes in VE-cad phosphorylation. In fact, a nonphosphorylatable VE-cad mutant prevented TEM. In summary, our studies provide compelling evidence that VE-cad gap formation is required for leukocyte transmigration and identify p120 as a critical intracellular mediator of this process through its regulation of VE-cad expression at junctions.

scholarly journals p120-Catenin prevents neutrophil transmigration independently of RhoA inhibition by impairing Src dependent VE-cadherin phosphorylation

2012 ◽  
Vol 303 (4) ◽  
pp. C385-C395 ◽  
Author(s):  
Pilar Alcaide ◽  
Roberta Martinelli ◽  
Gail Newton ◽  
Marcie R. Williams ◽  
Alejandro Adam ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tyrosine Phosphorylation ◽  
Umbilical Vein ◽  
Surface Expression ◽  
Vascular Endothelial ◽  
P120 Catenin ◽  
Rhoa Activation ◽  
Vascular Endothelial Cadherin ◽  
Leukocyte Transendothelial Migration ◽  
Umbilical Vein Endothelial Cells

Leukocyte transendothelial migration (TEM) is regulated by several signaling pathways including Src family kinases (SFK) and the small RhoGTPases. Previous studies have shown that vascular endothelial-cadherin (VE-cad) forms a complex with β-,γ-, and p120-catenins and this complex disassociates to form a transient gap during leukocyte TEM. Additionally, p120-catenin (p120-1A) overexpression in human umbilical vein endothelial cells (HUVEC) stabilizes VE-cad surface expression, prevents tyrosine phosphorylation of VE-cad, and inhibits leukocyte TEM. Based on reports showing that p120 overexpression in fibroblasts or epithelial cells inhibits RhoA and activates Rac and Cdc42 GTPases, and on other reports showing that RhoA activation in endothelial cells is necessary for leukocyte TEM, we reasoned that p120 overexpression inhibited TEM through inhibition of RhoA. To test this idea, we overexpressed a mutant p120 isoform, p120-4A, which does not interact with RhoA. p120-4A colocalized with VE-cad in HUVEC junctions and enhanced VE-cad surface expression, similar to overexpression of p120-1A. Interestingly, overexpression of either p120-4A or p120-1A dramatically blocked TEM, and overexpression of p120-1A in HUVEC did not affect RhoA basal activity or activation of RhoA and Rac induced by thrombin or ICAM-1 crosslinking. In contrast, biochemical studies revealed that overexpression of p120-1A reduced activated pY416-Src association with VE-cad. In summary, p120 overexpression inhibits neutrophil TEM independently of an effect on RhoA or Rac and instead blocks TEM by preventing VE-cad tyrosine phosphorylation and association of active Src with the VE-cad complex.

scholarly journals REGULATION OF LEUKOCYTE TRANSENDOTHELIAL MIGRATION BY P120 CATENIN/ VASCULAR ENDOTHELIAL‐CADHERIN

2007 ◽  
Vol 21 (6) ◽  
Author(s):  
Pilar Alcaide ◽  
Gail Newton ◽  
Seema Sehrawat ◽  
Tanya Mayadas‐Norton ◽  
Francis William Luscinskas
Keyword(s):  
Transendothelial Migration ◽  
Vascular Endothelial ◽  
P120 Catenin ◽  
Vascular Endothelial Cadherin ◽  
Leukocyte Transendothelial Migration

scholarly journals Interfering with VE-PTP stabilizes endothelial junctions in vivo via Tie-2 in the absence of VE-cadherin

2015 ◽  
Vol 212 (13) ◽  
pp. 2267-2287 ◽  
Author(s):  
Maike Frye ◽  
Martina Dierkes ◽  
Verena Küppers ◽  
Matthias Vockel ◽  
Janina Tomm ◽  
...  
Keyword(s):  
Tyrosine Phosphatase ◽  
Endothelial Barrier ◽  
Vascular Endothelial ◽  
Leukocyte Transmigration ◽  
Gene Ablation ◽  
Nonmuscle Myosin Ii ◽  
Endothelial Junctions ◽  
The Stability ◽  
Endothelial Junction

Vascular endothelial (VE)–protein tyrosine phosphatase (PTP) associates with VE-cadherin, thereby supporting its adhesive activity and endothelial junction integrity. VE-PTP also associates with Tie-2, dampening the tyrosine kinase activity of this receptor that can support stabilization of endothelial junctions. Here, we have analyzed how interference with VE-PTP affects the stability of endothelial junctions in vivo. Blocking VE-PTP by antibodies, a specific pharmacological inhibitor (AKB-9778), and gene ablation counteracted vascular leak induction by inflammatory mediators. In addition, leukocyte transmigration through the endothelial barrier was attenuated. Interference with Tie-2 expression in vivo reversed junction-stabilizing effects of AKB-9778 into junction-destabilizing effects. Furthermore, lack of Tie-2 was sufficient to weaken the vessel barrier. Mechanistically, inhibition of VE-PTP stabilized endothelial junctions via Tie-2, which triggered activation of Rap1, which then caused the dissolution of radial stress fibers via Rac1 and suppression of nonmuscle myosin II. Remarkably, VE-cadherin gene ablation did not abolish the junction-stabilizing effect of the VE-PTP inhibitor. Collectively, we conclude that inhibition of VE-PTP stabilizes challenged endothelial junctions in vivo via Tie-2 by a VE-cadherin–independent mechanism. In the absence of Tie-2, however, VE-PTP inhibition destabilizes endothelial barrier integrity in agreement with the VE-cadherin–supportive effect of VE-PTP.

scholarly journals Regulation of endothelial barrier function by p120-catenin∙VE-cadherin interaction

2017 ◽  
Vol 28 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Joshua P. Garrett ◽  
Anthony M. Lowery ◽  
Alejandro P. Adam ◽  
Andrew P. Kowalczyk ◽  
Peter A. Vincent
Keyword(s):  
Barrier Function ◽  
Electrical Resistance ◽  
Vascular Endothelial ◽  
Transendothelial Electrical Resistance ◽  
Endothelial Barrier Function ◽  
P120 Catenin ◽  
Vascular Endothelial Cadherin ◽  
Phosphorylated Form ◽  
Defective Mutant ◽  
Sprout Formation

Endothelial p120-catenin (p120) maintains the level of vascular endothelial cadherin (VE-Cad) by inhibiting VE-Cad endocytosis. Loss of p120 results in a decrease in VE-Cad levels, leading to the formation of monolayers with decreased barrier function (as assessed by transendothelial electrical resistance [TEER]), whereas overexpression of p120 increases VE-Cad levels and promotes a more restrictive monolayer. To test whether reduced endocytosis mediated by p120 is required for VE-Cad formation of a restrictive barrier, we restored VE-Cad levels using an endocytic-defective VE-Cad mutant. This endocytic-defective mutant was unable to rescue the loss of TEER associated with p120 or VE-Cad depletion. In contrast, the endocytic-defective mutant was able to prevent sprout formation in a fibrin bead assay, suggesting that p120•VE-Cad interaction regulates barrier function and angiogenic sprouting through different mechanisms. Further investigation found that depletion of p120 increases Src activity and that loss of p120 binding results in increased VE-Cad phosphorylation. In addition, expression of a Y658F–VE-Cad mutant or an endocytic-defective Y658F–VE-Cad double mutant were both able to rescue TEER independently of p120 binding. Our results show that in addition to regulating endocytosis, p120 also allows the phosphorylated form of VE-Cad to participate in the formation of a restrictive monolayer.

NADPH oxidase mediates vascular endothelial cadherin phosphorylation and endothelial dysfunction

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3214-3220 ◽  
Author(s):  
Fiemu E. Nwariaku ◽  
Zijuan Liu ◽  
Xudong Zhu ◽  
Dorit Nahari ◽  
Christine Ingle ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Cell Junctions ◽  
Vascular Endothelial ◽  
Gap Formation ◽  
Vascular Endothelial Cadherin ◽  
Adenoviral Delivery ◽  
Oxidant Production ◽  
Jnk Activation

Abstract Vascular endothelial activation is an early step during leukocyte/endothelial adhesion and transendothelial leukocyte migration in inflammatory states. Leukocyte transmigration occurs through intercellular gaps between endothelial cells. Vascular endothelial cadherin (VE-cadherin) is a predominant component of endothelial adherens junctions that regulates intercellular gap formation. We found that tumor necrosis factor (TNF) caused tyrosine phosphorylation of VE-cadherin, separation of lateral cell-cell junctions, and intercellular gap formation in human umbilical vein endothelial cell (HUVEC) monolayers. These events appear to be regulated by intracellular oxidant production through endothelial NAD(P)H (nicotinamide adenine dinucleotide phosphate) oxidase because antioxidants and expression of a transdominant inhibitor of the NADPH oxidase, p67(V204A), effectively blocked the effects of TNF on all 3 parameters of junctional integrity. Antioxidants and p67(V204A) also decreased TNF-induced JNK activation. Dominant-negative JNK abrogated VE-cadherin phosphorylation and junctional separation, suggesting a downstream role for JNK. Finally, adenoviral delivery of the kinase dead PAK1(K298A) decreased TNF-induced JNK activation, VE-cadherin phosphorylation, and lateral junctional separation, consistent with the proposed involvement of PAK1 upstream of the NADPH oxidase. Thus, PAK-1 acts in concert with oxidase during TNF-induced oxidant production and loss of endothelial cell junctional integrity.

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