NWASP regulates neuroinflammation and cognition in Alzheimer's disease

项目总结/摘要 增加的细胞旁通透性是急性肺损伤的标志，并且是肺功能衰竭的潜在机制。 上皮和内皮屏障都需要进一步研究。患者发病率和死亡率高 急性肺损伤的特征是充满充满蛋白质的水肿。我们之前 报道Rho GT3激活在渗透性紊乱和肌动蛋白应力纤维中起关键作用 在肺微血管内皮细胞和肺泡上皮细胞中形成。此外，Rho GT3的抑制 保护了肺内皮和肺泡上皮屏障功能的完整性， 在铜绿假单胞菌（P. aeruginosa）肺炎的鼠模型中的清除率。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 内皮细胞和肺泡上皮细胞，并导致细胞旁通透性紊乱，是不完全的， 明白活性小Rho GTdR从神经元中解锁神经元Wiskott-Aldrich综合征蛋白（NWASP）。 自抑制构象激活。NWASP直接将上游信号传输到细胞机器 参与调节细胞骨架动力学。我们的初步数据和已发表的工作表明，（a） NWASP下调抑制肌动蛋白应力纤维形成并降低肺细胞旁通透性 暴露于铜绿假单胞菌或TGF-β1后的微血管内皮细胞和肺泡上皮细胞;（B） 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功能， 在与细菌诱导的肺水肿相关的肺水肿发展中的关键开关（“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 肺内皮和肺泡上皮的屏障功能。为了验证这一假设，我们提出了三个 具体目标：（目标1）确定西北地区和太平洋地区战略的下游伙伴和关键领域， 促进铜绿假单胞菌诱导的肺微血管内皮细胞和肺泡上皮细胞通透性;（目的 2)以确定共同的，和差异的，分子机制，通过它激活的GBD 转换改变细胞骨架动力学，破坏屏障功能，并导致肺中的细胞旁通透性 微血管内皮细胞和肺泡上皮细胞对铜绿假单胞菌的反应;（目的3）确定 NWASP在铜绿假单胞菌引起急性肺损伤小鼠模型中的体内和细胞类型特异性作用 肺炎这些研究的结果将有助于阐明调节细胞凋亡的分子机制。 铜绿假单胞菌诱导的急性肺损伤中的细胞骨架动力学、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.