The mechanical property of neutrophils to inflammatory process and sequestration into the lung.

中性粒细胞对炎症过程和肺隔离的机械特性。

• 批准号: 15591912
• 负责人: SAITO Hajime
• 金额: $ 1.92万
• 依托单位: Akita University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15591912/
• 关键词: neutrophils; transmigration; sequestration; lung injury; deformability; actin; bone marrow release; antithrombin; bone marroW release; Cdc42; small G protein

Because the spherical diameter of pulmonary capillaries is smaller than that of neutrophils, increased neutrophil stiffness or, conversely, decreased neutrophil deformability is a key step in the initial sequestration of neutrophils within the lungs during inflammatory processes. Antithrombin III (AT) is known exert a therapeutic effect against disseminated intravascular coagulation, and accumulating evidence suggests that AT also has anti-inflammatory properties. The mechanisms of its anti-inflammatory effects remain unclear, but in a rat endotoxin model AT apparently inhibited neutrophil sequestration in the lung. In the present in vitro study, therefore, we examined the effect of AT on the deformability of human neutrophils and correlated those findings with their F-actin content. Isolated human neutrophils were stimulated with fMLP (1 μM, 2 min) in the presence or absence of the α, β or low-heparin-affinity isoforms of AT (1 IU/ml, 20 min), and deformability was evaluated using a filter assay system. Neutrophils were also stained with FITC-phalloidin and subjected to FACS-scan to assess F-actin content. The results showed that pretreatment with any of the three AT isoforms similarly inhibited the decreased neutrophil deformability and increased F-actin content. Notably, heparinase had no effect on either deformability or F-actin content in the presence or absence of AT, which was somewhat unexpected, as heparin sulfate proteoglycans likely function as AT receptors. These findings suggested that AT inhibits the increase in neutrophil stiffness seen during inflammatory processes by inhibiting actin polymerization via a heparin-independent pathway.

因为肺毛细血管的球形直径小于中性粒细胞的球形直径，中性粒细胞刚度增加，或者相反，嗜中性粒细胞可变形性降低是炎症过程中肺部肺中嗜中性粒细胞最初疗程的关键步骤。已知抗凝血酶III（AT）对弥散性血管内凝血发挥治疗作用，并且积累的证据表明，AT还具有抗炎特性。其抗炎作用的机制尚不清楚，但是在大鼠内毒素模型中，在明显抑制肺中的中性粒细胞固相。因此，在目前的体外研究中，我们检查了AT对人类嗜中性粒细胞的可变形性的影响，并将这些发现与其F-肌动蛋白含量相关联。在存在或不存在α，β或低肝素 - 亲和力同工型的情况下，用FMLP（1μM，2分钟）刺激分离的人类嗜中性粒细胞，并使用过滤器分析系统评估AT（1 IU/mL，20分钟）的AT（1 IU/mL，20分钟）。中性粒细胞还用FITC-甲状腺素染色，并受到FACS扫描以评估F-肌动蛋白含量。结果表明，使用三种AT的任何一个AT AT的预处理类似地抑制了中性粒细胞可变形性降低和F-肌动蛋白含量增加。值得注意的是，在存在或不存在AT的情况下，肝素酶对可变形性或F-肌动蛋白含量没有影响，因为硫酸肝素蛋白聚糖可能与受体起作用。这些发现表明，通过抑制炎症过程中嗜中性粒细胞刚度的增加，通过通过肝素独立途径抑制肌动蛋白聚合化。