Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA.
Cardiovasc Res. 2012 Mar 1;93(3):406-13. doi: 10.1093/cvr/cvr308. Epub 2011 Nov 18.
In atherosclerosis and restenosis, vascular smooth muscle cells (SMCs) migrate into the subendothelial space and proliferate, contributing to neointimal formation. The goal of this study was to define the signalling pathway by which Nox1 NAPDH oxidase mediates SMC migration.
SMCs were cultured from thoracic aorta from Nox1(-/y) (Nox1 knockout, KO) and wild-type (WT) mice. In response to thrombin, WT but not Nox1 KO SMCs generated increased levels of reactive oxygen species (ROS). Deficiency of Nox1 prevented thrombin-induced phosphorylation of Src and the subsequent transactivation of the epidermal growth factor receptor (EGFR) at multiple tyrosine residues. Next, activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and matrix metalloproteinase-9 (MMP-9) by thrombin was inhibited by the EGFR inhibitor AG1478 and in Nox1 KO SMCs. Thrombin-induced shedding of N-cadherin from the plasma membrane was dependent on the presence of Nox1 and was blocked by AG1478 and an inhibitor of metalloproteinases. Migration of SMCs to thrombin was impaired in the Nox1 KO SMCs and was restored by expression of Nox1. Finally, treatment of WT SMCs with AG1478 abrogated Nox1-dependent SMC migration.
The Nox1 NADPH oxidase signals through EGFR to activate MMP-9 and promote the shedding of N-cadherin, thereby contributing to SMC migration.
在动脉粥样硬化和再狭窄中，血管平滑肌细胞（SMC）迁移到血管内皮下空间并增殖，导致新生内膜形成。本研究旨在确定 Nox1 NADPH 氧化酶介导 SMC 迁移的信号通路。
从 Nox1(-/y)（Nox1 敲除，KO）和野生型（WT）小鼠的胸主动脉培养 SMC。在凝血酶的刺激下，WT 但不是 Nox1 KO 的 SMC 产生了更高水平的活性氧（ROS）。Nox1 的缺乏阻止了凝血酶诱导的Src 磷酸化，以及随后表皮生长因子受体（EGFR）在多个酪氨酸残基上的转激活。接下来，通过凝血酶激活的细胞外信号调节激酶 1/2（ERK1/2）和基质金属蛋白酶-9（MMP-9）在 Nox1 KO 的 SMC 中被 EGFR 抑制剂 AG1478 抑制。凝血酶诱导的 N-钙粘蛋白从质膜上的脱落依赖于 Nox1 的存在，并被 AG1478 和金属蛋白酶抑制剂所阻断。在 Nox1 KO 的 SMC 中，SMC 向凝血酶的迁移受损，而通过表达 Nox1 可以恢复迁移。最后，用 AG1478 处理 WT SMC 可以消除 Nox1 依赖性的 SMC 迁移。
Nox1 NADPH 氧化酶通过 EGFR 信号传递，激活 MMP-9 并促进 N-钙粘蛋白的脱落，从而促进 SMC 的迁移。
