Inhibition of Rac activity alleviates lipopolysaccharide-induced acute pulmonary injury in mice
Inhibition of Rac activity alleviates lipopolysaccharide-induced acute pulmonary injury in mice
复制标题
抑制 Rac 活性可减轻脂多糖诱导的小鼠急性肺损伤。
DOI：
10.1016/j.bbagen.2011.03.020
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发表时间：
2011-07-01
影响因子：
3
通讯作者：
Yan, Xiao-feng
中科院分区：
文献类型：
--
作者：
Yao, Hong-yi;Chen, Lihua;Yan, Xiao-feng
背景：Rac 小 GTP 酶在细胞骨架和许多细胞功能（包括细胞周期、细胞生长、细胞粘附和基因转录）中发挥重要作用。在此，我们研究了Rac（包括Rac1和Rac2）在脂多糖（LPS）诱导的肺损伤中的作用。方法：将LPS气管内滴注到小鼠肺部后，通过pull-down和West blot检测Rac、CDC42和RhoA活化，通过计数细胞数和肺组织学检查进行炎性细胞浸润测定，通过定量RT-PCR测定促炎介质mRNA表达，测量髓过氧化物酶（MPO）活性，使用其特异性抑制剂 NSC23766 进行伊文思蓝和白蛋白积累，以评估 Rac 在肺损伤中的作用。结果：LPS 激发导致肺中 Rac1 和 Rac2 的增加，但不抑制 CDC42 或 RhoA 的活性，腹腔注射 NSC23766 会抑制 Rac1 和 Rac2，但不抑制 CDC42 或 RhoA 的活性。用 1 或 3 mg/kg NSC23766 治疗不仅减少炎症细胞浸润和 MPO 活性，而且抑制促炎介质、肿瘤坏死因子-a 和白介素-1β mRNA 表达。此外，体外中性粒细胞迁移测定和体内微血管通透性测定表明，NSC23766不仅抑制中性粒细胞向化学引诱剂fMLP跨孔迁移，而且还减少LPS攻击的肺部中伊文思蓝和白蛋白的积累。 LPS同时激活Rac1和Rac2，但不激活肺部的CDC42或RhoA活性，NSC23766对Rac活性的特异性抑制有效减轻了LPS引起的损伤。一般意义：Rac可能成为肺部炎症治疗干预的潜在靶点。 (C) 2011 Elsevier B.V. 保留所有权利。
Background: Rac small GTPases play important roles in cytoskeleton and many cell functions including cell cycle, cell growth, cell adhesion and gene transcription. Here, we investigated the roles of Rac including Rac1 and Rac2 in lipopolysaccharide (LPS)-induced pulmonary injury.Methods: After LPS was intratracheally instilled to lungs in mice, Rac, CDC42 and RhoA activation assay by pull-down and West blot, inflammatory cell infiltration assay by counting cell numbers and lung histological examination, pro-inflammatory mediator mRNA expression assay by quantitative RT-PCR, measurement of myeloperoxidase (MPO) activity, Evans Blue and albumin accumulation by spectrophotometry were performed to evaluate the roles of Rac in pulmonary injury by using its specific inhibitor, NSC23766.Results: LPS challenge led to increases of both Rac1 and Rac2, but not CDC42 or RhoA activities in lungs, and intraperitoneal administration with NSC23766 inhibited both Rac1 and Rac2, but not CDC42 or RhoA activities. Treatment with NSC23766 at 1 or 3 mg/kg not only reduced the inflammatory cells infiltration and MPO activities, but also inhibited pro-inflammatory mediators, tumor necrosis factor-a and interleukin-1 beta, mRNA expression. Moreover, in vitro neutrophil migration assay and in vivo microvascular permeability assay indicated that NSC23766 not only inhibited neutrophil transwell migration toward a chemoattractant, fMLP, but also reduced Evans Blue and albumin accumulation in LPS-challenged lungs. LPS activated both Rac1 and Rac2, but not CDC42 or RhoA activities in lungs, and specific inhibition of Rac activities by NSC23766 effectively alleviated LPS-induced injury.General significance: Rac could be a potential target for therapeutic intervention of pulmonary inflammation. (C) 2011 Elsevier B.V. All rights reserved.