Phospholipase C-ε signaling mediates endothelial cell inflammation and barrier disruption in acute lung injury
Phospholipase C-ε signaling mediates endothelial cell inflammation and barrier disruption in acute lung injury
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DOI：
10.1152/ajplung.00069.2016
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发表时间：
2016-08-01
影响因子：
4.9
通讯作者：
Rahman, Arshad
中科院分区：
文献类型：
--
作者：
Bijli, Kaiser M.;Fazal, Fabeha;Rahman, Arshad
磷脂酶 C-epsilon (PLC-epsilon) 是一种独特的 PLC 同工型，可以通过来自 Ras 家族 GTP 酶和异三聚体 G 蛋白的多个信号输入进行调节，并且在心脏和肺中具有主要表达位点。尽管 PLC-ε 在心脏功能和病理学中的作用已被记录，但其在急性肺损伤 (ALI) 中的相关性尚不清楚。我们使用 PLC-epsilon(-/-) 小鼠来研究 PLC-epsilon 在气雾化细菌 LPS 吸入 ALI 小鼠模型中调节肺血管炎症和损伤的作用。 PLC-epsilon(-/-)小鼠表现出LPS诱导的促炎介质（ICAM-1、VCAM-1、TNF-α、IL-1β、IL-6、巨噬细胞炎症蛋白2、角质形成细胞源性细胞因子、单核细胞趋化蛋白1和粒细胞-巨噬细胞集落刺激因子）、肺中性粒细胞浸润和微血管渗漏以及肺中性粒细胞浸润和微血管渗漏的显着减少。 VE-钙粘蛋白与PLC-epsilon(+/+)小鼠的比较。这些数据表明 PLC-epsilon 是肺部促炎和渗漏表型的关键决定因素。为了测试内皮细胞 (EC) 中 PLC-epsilon 活性可能导致 ALI 的可能性，我们确定了它在 EC 炎症和屏障破坏中的作用。在 EC 中，PLC-epsilon 的 RNAi 敲低抑制了 NF-kappa B 响应多种促炎刺激、凝血酶、LPS、TNF-α 和非受体激动剂佛波醇 13-肉豆蔻酸酯 12-乙酸酯（佛波酯）的活性。 PLC-epsilon 的耗尽也抑制了凝血酶诱导的 NF-κ B 靶基因 VCAM-1 的表达。重要的是，PLC-epsilon 敲低还通过抑制粘附连接处 VE-钙粘蛋白的损失和肌动蛋白应力纤维的形成，防止凝血酶诱导的 EC 屏障破坏。这些数据表明 PLC-epsilon 是 EC 炎症和渗透性的新型调节剂，并显示 PLC-epsilon 在 ALI 发病机制中迄今未知的作用。
Phospholipase C-epsilon (PLC-epsilon) is a unique PLC isoform that can be regulated by multiple signaling inputs from both Ras family GTPases and heterotrimeric G proteins and has primary sites of expression in the heart and lung. Whereas the role of PLC-epsilon in cardiac function and pathology has been documented, its relevance in acute lung injury (ALI) is unclear. We used PLC-epsilon(-/-) mice to address the role of PLC-epsilon in regulating lung vascular inflammation and injury in an aerosolized bacterial LPS inhalation mouse model of ALI. PLC-epsilon(-/-) mice showed a marked decrease in LPS-induced proinflammatory mediators (ICAM-1, VCAM-1, TNF-alpha, IL-1 beta, IL-6, macrophage inflammatory protein 2, keratinocyte-derived cytokine, monocyte chemoattractant protein 1, and granulocyte-macrophage colony-stimulating factor), lung neutrophil infiltration and microvascular leakage, and loss of VE-cadherin compared with PLC-epsilon(+/+) mice. These data identify PLC-epsilon as a critical determinant of proinflammatory and leaky phenotype of the lung. To test the possibility that PLC-epsilon activity in endothelial cells (EC) could contribute to ALI, we determined its role in EC inflammation and barrier disruption. RNAi knockdown of PLC-epsilon inhibited NF-kappa B activity in response to diverse proinflammatory stimuli, thrombin, LPS, TNF-alpha, and the nonreceptor agonist phorbol 13-myristate 12-acetate (phorbol esters) in EC. Depletion of PLC-epsilon also inhibited thrombin-induced expression of NF-kappa B target gene, VCAM-1. Importantly, PLC-epsilon knockdown also protected against thrombin-induced EC barrier disruption by inhibiting the loss of VE-cadherin at adherens junctions and formation of actin stress fibers. These data identify PLC-epsilon as a novel regulator of EC inflammation and permeability and show a hitherto unknown role of PLC-epsilon in the pathogenesis of ALI.