The effect of Rho and FA for neutrophil transendothelial migration

中性粒细胞的跨内皮迁移是急性炎症的关键步骤，我们之前发现这是由内皮肌球蛋白轻链激酶调节的。最近的研究表明Rho和Rho激酶也是肌球蛋白轻链（MLC）磷酸化的关键介质，但它们在中性粒细胞迁移中的作用尚未被研究。在本研究中，采用含内皮单层的跨井室迁移测定系统，在体外中性粒细胞迁移过程中，在选定时间检测迁移中性粒细胞的数量、内皮f -肌动蛋白和肌球蛋白II重排以及内皮MLC磷酸化。结果表明，用C3 （Rho抑制剂）或Y-27632 （Rho激酶抑制剂）预处理内皮细胞可显著减少中性粒细胞迁移、肌动蛋白聚合、肌球蛋白II细丝形成、MLC磷酸化、酪氨酸磷酸化通常与迁移相关的paxillin。这些数据表明，内皮细胞Rho和Rho激酶通过酪氨酸磷酸化局灶黏附，通过调节介导这种迁移的细胞骨架事件来调节跨内皮中性粒细胞的迁移。

The transendothelial migration of neutrophils is a critical step in acute inflammation, which we previously showed to be regulated by endothelial myosin light chain kinase. Recent studies suggest that Rho and Rho kinase are also key mediators of myosin light chain (MLC) phosphorylation, but their roles in neutrophil migration has not been investigated. In the present study, a transwell chamber migration assay system incorporating endothelial monolayer was used to examined the numbers of migrating neutrophils, endothelial F-actin and myosin II rearrangement and endothelial MLC phosphorylation at selected times during the neutrophil migration, in vitro. The results showed that pretreating endothelial cells with C3 (Rho inhibitor) or Y-27632 (Rho kinase inhibitor) significantly diminished neutrophil migration, actin polymerization, myosin II filament formation, MLC phosphorylation, tyrosine phosphorylation of paxillin normally associated with the migration. These data suggest that endothelial Rho and Rho kinase regulate transendothelial neutrophil migration via tyrosine phosphorylation of focal adhesion by modulating the cytoskeletal events that mediate such migration.