Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan, ROC.
Biochem J. 2012 Jul 1;445(1):125-33. doi: 10.1042/BJ20111383.
β₂-GPI (β₂-glycoprotein I) is a plasma glycoprotein ascribed with an anti-angiogenic function; however, the biological role and molecular basis of its action in cell migration remain unknown. The aim of the present study was to assess the contribution of β₂-GPI to HAEC (human aortic endothelial cell) migration and the details of its underlying mechanism. Using wound healing and Boyden chamber assays, we found that β₂-GPI inhibited endothelial cell migration, which was restored by its neutralizing antibody. NF-κB (nuclear factor κB) inhibitors and lentiviral siRNA (small interfering RNA) silencing of NF-κB significantly attenuated the inhibitory effect of β₂-GPI on cell migration. Moreover, β₂-GPI was found to induce IκBα (inhibitor of NF-κB) phosphorylation and translocation of p65 and p50. We further demonstrated that mRNA and protein levels of eNOS [endothelial NO (nitric oxide) synthase] and NO production were all increased by β₂-GPI and these effects were remarkably inhibited by NF-κB inhibitors and siRNAs of p65 and p50. Furthermore, β₂-GPI-mediated inhibition of cell migration was reversed by eNOS inhibitors and eNOS siRNAs. The findings of the present study provide novel insight into the ability of β₂-GPI to inhibit endothelial cell migration predominantly through the NF-κB/eNOS/NO signalling pathway, which indicates a potential direction for clinical therapy in vascular diseases.
β₂-糖蛋白 I（β₂-GPI）是一种血浆糖蛋白，具有抗血管生成功能；然而，其在细胞迁移中的作用的生物学功能和分子基础尚不清楚。本研究旨在评估β₂-GPI 对人主动脉内皮细胞（HAEC）迁移的贡献及其潜在机制的细节。通过划痕愈合和 Boyden 室测定，我们发现β₂-GPI 抑制内皮细胞迁移，其中和抗体可恢复细胞迁移。NF-κB（核因子 κB）抑制剂和 NF-κB 的慢病毒 siRNA（小干扰 RNA）沉默显著减弱了β₂-GPI 对细胞迁移的抑制作用。此外，β₂-GPI 被发现诱导 IκBα（NF-κB 抑制剂）磷酸化和 p65 和 p50 的易位。我们进一步证明，β₂-GPI 增加了 eNOS [内皮型一氧化氮合酶]的 mRNA 和蛋白水平以及 NO 的产生，这些作用被 NF-κB 抑制剂和 p65 和 p50 的 siRNAs 显著抑制。此外，eNOS 抑制剂和 eNOS siRNAs 逆转了β₂-GPI 介导的细胞迁移抑制。本研究的结果为β₂-GPI 抑制内皮细胞迁移的能力主要通过 NF-κB/eNOS/NO 信号通路提供了新的见解，这为血管疾病的临床治疗指明了一个潜在的方向。
