The C-terminus region of β-arrestin1 modulates VE-cadherin expression and endothelial cell permeability.
The C-terminus region of β-arrestin1 modulates VE-cadherin expression and endothelial cell permeability.
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DOI：
10.1186/1478-811x-11-37
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发表时间：
2013-05-28
期刊：
影响因子：
--
通讯作者：
Gavard J
中科院分区：
文献类型：
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作者：
Hebda JK;Leclair HM;Azzi S;Roussel C;Scott MG;Bidère N;Gavard J
内皮特异性细胞间粘附分子 VE-钙粘蛋白可调节屏障功能和血管稳态。在这种情况下，我们之前已经描述了 VEGF（血管内皮生长因子）会导致小鼠内皮细胞中 VE-钙粘蛋白磷酸化、β-arrestin2 募集和 VE-钙粘蛋白内化。然而，这种 VE-钙粘蛋白/β-抑制蛋白复合物究竟如何影响人内皮细胞中 VEGF 介导的通透性仍不清楚。在这项研究中，我们深入研究了暴露于 VEGF 的人内皮细胞中 VE-钙粘蛋白/β-抑制蛋白的相互作用。首先，我们证明 VEGF 在人脐静脉内皮细胞 (HUVEC) 中以网格蛋白依赖性方式诱导 VE-钙粘蛋白内化。除了内吞囊泡的经典成分外，β-arrestin1 也被招募并与磷酸化的 VE-钙粘蛋白结合。这种相互作用的分子图谱揭示了 β-arrestin1 的 C 末端尾部（包含氨基酸 375 至 418）足以直接与磷酸化形式的 VE-钙粘蛋白相互作用。有趣的是，β-arrestin1 C 末端尾部的表达诱导表面暴露的 VE-钙粘蛋白的损失，促进单层解体并增强通透性。最后，这种效应依赖于通过抑制 VE-钙粘蛋白的启动子活性，在转录水平上降低 VE-钙粘蛋白的表达。总而言之，我们的结果表明 β-arrestin1 可能发挥多种功能，共同促进内皮屏障特性。事实上，除了直接影响 VE-钙粘蛋白内吞作用外，β-arrestin1 还可以控制 VE-钙粘蛋白转录和表达。最终，了解 VE-钙粘蛋白功能所涉及的分子机制可能为许多血管屏障受损的人类疾病提供治疗工具。
The endothelial specific cell-cell adhesion molecule, VE-cadherin, modulates barrier function and vascular homeostasis. In this context, we have previously characterized that VEGF (vascular endothelial growth factor) leads to VE-cadherin phosphorylation, β-arrestin2 recruitment and VE-cadherin internalization in mouse endothelial cells. However, exactly how this VE-cadherin/β-arrestin complex contributes to VEGF-mediated permeability in human endothelial cells remains unclear. In this study, we investigated in-depth the VE-cadherin/β-arrestin interactions in human endothelial cells exposed to VEGF. First, we demonstrated that VEGF induces VE-cadherin internalization in a clathrin-dependent manner in human umbilical vein endothelial cells (HUVEC). In addition to the classical components of endocytic vesicles, β-arrestin1 was recruited and bound to phosphorylated VE-cadherin. Molecular mapping of this interaction uncovered that the C-terminus tail of β-arrestin1, that comprises amino acids 375 to 418, was sufficient to directly interact with the phosphorylated form of VE-cadherin. Interestingly, the expression of the C-terminus tail of β-arrestin1 induced loss of surface exposed-VE-cadherin, promoted monolayer disorganization and enhanced permeability. Finally, this effect relied on decreased VE-cadherin expression at the transcriptional level, through inhibition of its promoter activity. Altogether, our results demonstrate that β-arrestin1 might play multiple functions collectively contributing to endothelial barrier properties. Indeed, in addition to a direct implication in VE-cadherin endocytosis, β-arrestin1 could also control VE-cadherin transcription and expression. Ultimately, understanding the molecular mechanisms involved in VE-cadherin function might provide therapeutic tools for many human diseases where the vascular barrier is compromised.