p120-Catenin prevents neutrophil transmigration independently of RhoA inhibition by impairing Src dependent VE-cadherin phosphorylation
p120-Catenin prevents neutrophil transmigration independently of RhoA inhibition by impairing Src dependent VE-cadherin phosphorylation
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DOI：
10.1152/ajpcell.00126.2012
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发表时间：
2012-08-01
影响因子：
5.5
通讯作者：
Luscinskas, Francis W.
中科院分区：
文献类型：
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作者：
Alcaide, Pilar;Martinelli, Roberta;Luscinskas, Francis W.
Alcaide P，Martinelli R，Newton G，威廉姆斯MR，Adam A，Vincent PA，Luscinskas FW. p120-连环蛋白通过损害Src依赖的VE-钙粘蛋白磷酸化作用，独立于RhoA抑制而阻止中性粒细胞迁移。Am J Physiol Cell Physiol 303：C385-C395，2012.首次发表于2012年5月30日; doi：10.1152/ajpcell.00126.2012.-白细胞跨内皮迁移（transendothelial migration，TEM）受Src家族激酶（SFK）和小RhoGTP酶等多种信号通路的调控。以前的研究表明，血管内皮钙粘蛋白（VE-cad）与β-，γ-和p120-连环蛋白形成复合物，该复合物在白细胞TEM过程中解离形成短暂的间隙。此外，p120-catenin（p120-1A）在人脐静脉内皮细胞（HUVEC）中的过表达稳定了VE-cad表面表达，阻止了VE-cad的酪氨酸磷酸化，并抑制了白细胞TEM。基于显示成纤维细胞或上皮细胞中p120过表达抑制RhoA并激活Rac和Cdc 42 GTP酶的报道，以及显示内皮细胞中RhoA激活对于白细胞TEM是必需的其他报道，我们推断p120过表达通过抑制RhoA来抑制TEM。为了验证这一想法，我们过表达了一种突变型p120亚型p120-4A，它不与RhoA相互作用。p120-4A与VE-cad共定位于HUVEC连接处，并增强VE-cad表面表达，类似于p120-1A的过表达。有趣的是，p120-4A或p120-1A的过表达显著地阻断TEM，并且p120-1A在HUVEC中的过表达不影响RhoA基础活性或由凝血酶或ICAM-1交联诱导的RhoA和Rac的活化。相反，生物化学研究表明，p120-1A的过表达减少了激活的pY 416-Src与VE-cad的关联。总之，p120过表达抑制嗜中性粒细胞TEM独立于对RhoA或Rac的影响，而是通过阻止VE-cad酪氨酸磷酸化和活性Src与VE-cad复合物的结合来阻断TEM。
Alcaide P, Martinelli R, Newton G, Williams MR, Adam A, Vincent PA, Luscinskas FW. p120-Catenin prevents neutrophil transmigration independently of RhoA inhibition by impairing Src dependent VE-cadherin phosphorylation. Am J Physiol Cell Physiol 303: C385-C395, 2012. First published May 30, 2012; doi:10.1152/ajpcell.00126.2012.-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 beta-, gamma-, 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.