Department of Biotechnology and Molecular Medicine, AI Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
Arterioscler Thromb Vasc Biol. 2011 Jul;31(7):1617-24. doi: 10.1161/ATVBAHA.111.225961. Epub 2011 Apr 7.
The mature form of human vascular endothelial growth factor-D (hVEGF-D(ΔNΔC)) is an efficient angiogenic factor, but its full mechanism of action has remained unclear. We studied the effects of hVEGF-D(ΔNΔC) in endothelial cells using gene array, signaling, cell culture, and in vivo gene transfer techniques.
Concomitant with the angiogenic and proliferative responses, hVEGF-D(ΔNΔC) enhanced the phosphorylation of VEGF receptor-2, Akt, and endothelial nitric oxide synthase. Gene arrays, quantitative reverse transcription-polymerase chain reaction, and Western blot revealed increases in VEGF-A, stanniocalcin-1 (STC1), and neuropilin (NRP) 2 expression by hVEGF-D(ΔNΔC) stimulation, whereas induction with hVEGF-A(165) altered the expression of STC1 and NRP1, another coreceptor for VEGFs. The effects of hVEGF-D(ΔNΔC) were seen only under high-serum conditions, whereas for hVEGF-A(165), the strongest response was observed under low-serum conditions. The hVEGF-D(ΔNΔC)-induced upregulation of STC1 and NRP2 was also evident in vivo in mouse skeletal muscle treated with hVEGF-D(ΔNΔC) by adenoviral gene delivery. The importance of NRP2 in hVEGF-D(ΔNΔC) signaling was further studied with NRP2 small interfering RNA and NRP antagonist, which were able to block hVEGF-D(ΔNΔC)-induced survival of endothelial cells.
In this study, the importance of serum and upregulation of NRP2 and STC1 for VEGF-D(ΔNΔC) effects were demonstrated. Better knowledge of VEGF-D(ΔNΔC) signaling and regulation is valuable for the development of efficient and safe VEGF-D(ΔNΔC)-based therapeutic applications for cardiovascular diseases.
人类血管内皮生长因子-D（hVEGF-D（ΔNΔC））的成熟形式是一种有效的血管生成因子，但它的作用机制尚不完全清楚。我们使用基因阵列、信号转导、细胞培养和体内基因转导技术研究了 hVEGF-D（ΔNΔC）在血管内皮细胞中的作用。
与血管生成和增殖反应同时发生，hVEGF-D（ΔNΔC）增强了 VEGF 受体-2、Akt 和内皮型一氧化氮合酶的磷酸化。基因阵列、定量逆转录-聚合酶链反应和 Western blot 显示，hVEGF-D（ΔNΔC）刺激引起 VEGF-A、stanniocalcin-1（STC1）和神经纤毛蛋白（NRP）2 的表达增加，而 hVEGF-A（165）诱导引起 STC1 和 NRP1 的表达改变，NRP1 是 VEGFs 的另一个核心受体。只有在高血清条件下才能观察到 hVEGF-D（ΔNΔC）的作用，而对于 hVEGF-A（165），在低血清条件下观察到最强的反应。hVEGF-D（ΔNΔC）诱导的 STC1 和 NRP2 上调在通过腺病毒基因传递在小鼠骨骼肌中用 hVEGF-D（ΔNΔC）处理的体内也很明显。用 NRP2 小干扰 RNA 和 NRP 拮抗剂进一步研究了 NRP2 在 hVEGF-D（ΔNΔC）信号转导中的重要性，这两种物质能够阻断 hVEGF-D（ΔNΔC）诱导的内皮细胞存活。
在这项研究中，证明了血清的重要性以及 NRP2 和 STC1 的上调对 VEGF-D（ΔNΔC）作用的重要性。更好地了解 VEGF-D（ΔNΔC）信号转导和调节对于开发有效的和安全的基于 VEGF-D（ΔNΔC）的心血管疾病治疗应用具有重要意义。
