BackgroundAlteration in hemodynamic shear stress at atheroprone sites promotes endothelial paracellular pore formation and permeability. The molecular mechanism remains unknown.Methods and ResultsWe show that Nck (noncatalytic region of tyrosine kinase) deletion significantly ameliorates disturbed flow‐induced permeability, and selective isoform depletion suggests distinct signaling mechanisms. Only Nck1 deletion significantly reduces disturbed flow‐induced paracellular pore formation and permeability, whereas Nck2 depletion has no significant effects. Additionally, Nck1 re‐expression, but not Nck2, restores disturbed flow‐induced permeability in Nck1/2 knockout cells, confirming the noncompensating roles. In vivo, using the partial carotid ligation model of disturbed flow, Nck1 knockout prevented the increase in vascular permeability, as assessed by Evans blue and fluorescein isothiocyanate dextran extravasations and leakage of plasma fibrinogen into the vessel wall. Domain swap experiments mixing SH2 (phosphotyrosine binding) and SH3 (proline‐rich binding) domains between Nck1 and Nck2 showed a dispensable role for SH2 domains but a critical role for the Nck1 SH3 domains in rescuing disturbed flow‐induced endothelial permeability. Consistent with this, both Nck1 and Nck2 bind to platelet endothelial adhesion molecule‐1 (SH2 dependent) in response to shear stress, but only Nck1 ablation interferes with shear stress–induced PAK2 (p21‐activated kinase) membrane translocation and activation. A single point mutation into individual Nck1 SH3 domains suggests a role for the first domain of Nck1 in PAK recruitment to platelet endothelial cell adhesion molecule‐1 and activation in response to shear stress.ConclusionsThis work provides the first evidence that Nck1 but not the highly similar Nck2 plays a distinct role in disturbed flow‐induced vascular permeability by selective p21‐activated kinase activation.

中文翻译：

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Nck1，而不是Nck2，介导受干扰的血流诱导的p21激活的激酶激活和内皮通透性。

背景动脉粥样硬化部位血流动力学切应力的改变会促进内皮细胞旁孔的形成和通透性。方法和结果我们表明，Nck（酪氨酸激酶的非催化区域）的缺失显着改善了扰动的血流诱导通透性，选择性同工型耗竭表明了不同的信号传导机制。只有Nck1缺失才能显着减少扰动的血流诱导的旁细胞孔的形成和通透性，而Nck2的消耗则没有明显的作用。此外，Nck1的重新表达而不是Nck2的表达恢复了Nck1 / 2敲除细胞中扰动的血流诱导通透性，从而证实了无补偿作用。在体内，使用不规则的部分颈动脉结扎模型，Nck1敲除可防止血管通透性增加，如Evans蓝和异硫氰酸荧光素葡聚糖外渗以及血浆纤维蛋白原渗入血管壁所评估。域交换实验混合SH2（磷酸酪氨酸结合）和 SHNck1和Nck2之间的3个（富含脯氨酸的结合）结构域对 SH2个域，但对Nck1至关重要 SH抢救扰乱的血流诱导的内皮通透性的3个领域。与此相一致，Nck1和Nck2均与血小板内皮粘附分子-1（SH2依赖性）响应剪切应力，但只有Nck1消融干扰剪切应力引起的 派克2（p21激活的激酶）膜移位和激活。单点突变成单个Nck1SH3个域表明Nck1的第一个域在 派克 结论：这项工作提供了第一个证据，表明Nck1但不是高度相似的Nck2通过选择性的p21激活的激酶激活在扰动血流诱导的血管通透性中发挥了独特的作用。