NWASP regulates neuroinflammation and cognition in Alzheimer's disease

项目摘要/摘要 细胞旁通透性增加是急性肺损伤的一个标志，其失败的机制 上皮屏障和内皮屏障都需要进一步研究。患者高发病率和高死亡率 急性肺损伤的特点是空隙充斥，富含蛋白质的浮肿。我们之前 报道了Rho GTP酶的激活在通透性紊乱和肌动蛋白应激纤维中起着关键作用 肺微血管内皮细胞和肺泡上皮细胞的形成。此外，对Rho GTP酶的抑制 保护肺内皮细胞和肺泡上皮屏障功能的完整性，促进肺泡液的分泌 铜绿假单胞菌肺炎小鼠模型的清除。然而，分子 Rho GTP酶改变肺微血管细胞骨架动力学的下游机制(S) 内皮细胞和肺泡上皮细胞，并导致细胞旁通透性紊乱，不完全 明白了。激活的小Rho GTP酶解开神经元性Wiskott-Aldrich综合征蛋白(NWASP) 激活的自动抑制构象。NWASP将上行信号直接传输到蜂窝机器 参与细胞骨架动力学的调节。我们的初步数据和发表的工作表明：(A) NWASP下调抑制肺内肌动蛋白应激纤维形成并降低细胞旁通透性 铜绿假单胞菌或转化生长因子-β1暴露后的微血管内皮细胞和肺泡上皮细胞； 此外，抑制N-WASP可保护小鼠免受肺损伤，并提高小鼠模型的存活率 铜绿假单胞菌肺炎。我们假设NWASP的GBD结构域的激活作为一种 细菌所致肺水肿发生过程中的关键开关(GBD开关) 损伤，通过招募下游信号分子，促进细胞骨架动力学，并破坏 肺内皮细胞和肺泡上皮细胞的屏障功能。为了检验这一假设，我们提出了三个假设 具体目标：(目标1)确定西北太平洋的下游合作伙伴(S)和关键领域(S)，这是必不可少的 促进铜绿假单胞菌诱导的肺微血管内皮细胞和肺泡上皮通透性 2)确定共同的和不同的分子机制，激活的GBD Switch改变细胞骨架动力学，破坏屏障功能，并导致肺细胞旁通透性。 微血管内皮细胞和肺泡上皮细胞对铜绿假单胞菌的反应；(目标3)定义 NWASP在铜绿假单胞菌致小鼠急性肺损伤模型中的体内和细胞类型特异性作用 肺炎。这些研究的发现将有助于描绘调控的分子机制。 铜绿假单胞菌诱导的急性肺损伤的细胞骨架动力学、屏障功能和通透性。

Project Summary/Abstract Increased paracellular permeability is a hallmark of acute lung injury and the mechanisms underlying failure of both epithelial and endothelial barriers need to be further investigated. High morbidity and mortality in patients with acute lung injury is characterized by flooding of the airspaces with protein-rich edema. We previously reported that Rho GTPase activation plays a critical role in permeability derangements and actin stress fiber formation in lung microvascular endothelial and alveolar epithelial cells. Additionally, inhibition of Rho GTPase preserved the integrity of lung endothelial and alveolar epithelial barrier function and promoted alveolar fluid clearance in a murine model of Pseudomonas aeruginosa (P. aeruginosa) pneumonia. However, the molecular downstream mechanism(s) by which Rho GTPases alter cytoskeletal dynamics of lung microvascular endothelial and alveolar epithelial cells, and causes paracellular permeability derangements, is not fully understood. Active small Rho GTPase unlocks Neuronal Wiskott–Aldrich syndrome protein (NWASP) from an autoinhibited conformation for activation. NWASP transmits upstream signals to the cellular machinery directly involved in modulation of cytoskeletal dynamics. Our preliminary data and published work indicate that (a) NWASP downregulation inhibits actin stress fiber formation and reduces paracellular permeability in lung microvascular endothelial and alveolar epithelial cells after exposure to P. aeruginosa or TGF-β1; (b) Furthermore, inhibition of N-WASP protects mice against lung injury and improves survival in a murine model of P. aeruginosa pneumonia. We hypothesize that activation of the GBD domain of NWASP functions as a critical switch (the “GBD-switch”) in the development of lung edema associated with bacteria-induced lung injury, through recruiting downstream signaling molecules, promoting cytoskeletal dynamics, and disrupting barrier function of both lung endothelium and alveolar epithelium. To test this hypothesis, we propose three specific aims: (Aim 1) to define the downstream partner(s), and critical domain(s), of NWASP that are essential to promote lung microvascular endothelial and alveolar epithelial permeability induced by P. aeruginosa; (Aim 2) to determine the common, and differential, molecular mechanisms, by which the activated GBD switch alters cytoskeletal dynamics, disrupts barrier function, and causes paracellular permeability in lung microvascular endothelial cells and alveolar epithelial cells in response to P. aeruginosa; (Aim 3) to define the in vivo, and cell-type-specific, role of NWASP in a murine model of acute lung injury caused by P. aeruginosa pneumonia. The findings from these studies will help to delineate the molecular mechanisms regulating cytoskeletal dynamics, barrier function, and permeability in P. aeruginosa-induced acute lung injury.