Zhang Gang, Wang Rong, Cheng Ke, Li Qi, Wang Yu, Zhang Rongrong, Qin Xinyue
Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Front Neurol. 2017 Sep 26;8:504. doi: 10.3389/fneur.2017.00504. eCollection 2017.
Repulsive guidance molecule a (RGMa) is a major neuron guidance factor in central nervous systems. We previously found that inhibition of RGMa could greatly enhance neural function rehabilitation in rats after MCAO/reperfusion. Neuron guidance factors are often regulators of angiogenesis. However, the effect of RGMa on angiogenesis and its mechanisms remain to be determined. Here, we investigated the effect of RGMa on endothelial cell (EC) proliferation, migration, tube formation, and cytoskeleton reassembly. The addition of recombinant RGMa significantly decreased the proliferation, migration, and tube formation of ECs. It also decreased the level of phosphorylated focal adhesion kinase (p-FAK Tyr397). Furthermore, the F-actin of the cytoskeleton assembly was obviously suppressed, with decreased filopodia and lamellipodia after the addition of RGMa. Knockout of neogenin or Unc5b significantly diminished RGMa's inhibition of EC migration, tube formation, and cytoskeleton reassembly. RGMa-induced p-FAK (Tyr397) decrease was also abolished by knockout of neogenin or Unc5b. These results indicate that RGMa may be a negative regulator of angiogenesis through downregulating VEGF and p-FAK (Tyr397) neogenin and Unc5b .
排斥性导向分子a（RGMa）是中枢神经系统中的一种主要神经元导向因子。我们之前发现，抑制RGMa可显著增强大鼠大脑中动脉闭塞/再灌注后的神经功能恢复。神经元导向因子通常是血管生成的调节因子。然而，RGMa对血管生成的影响及其机制仍有待确定。在此，我们研究了RGMa对内皮细胞（EC）增殖、迁移、管腔形成和细胞骨架重组的影响。添加重组RGMa可显著降低EC的增殖、迁移和管腔形成。它还降低了磷酸化粘着斑激酶（p-FAK Tyr397）的水平。此外，细胞骨架组装的F-肌动蛋白明显受到抑制，添加RGMa后丝状伪足和片状伪足减少。敲除新基因或Unc5b可显著减弱RGMa对EC迁移、管腔形成和细胞骨架重组的抑制作用。敲除新基因或Unc5b也可消除RGMa诱导的p-FAK（Tyr397）降低。这些结果表明，RGMa可能通过下调VEGF和p-FAK（Tyr397）、新基因和Unc5b成为血管生成的负调节因子。
