Vascular Endothelial Growth Factor (VEGF)-D Stimulates VEGF-A, Stanniocalcin-1, and Neuropilin-2 and Has Potent Angiogenic Effects
Objective—The mature form of human vascular endothelial growth factor-D (hVEGF-DΔNΔC) is an efficient angiogenic factor, but its full mechanism of action has remained unclear. We studied the effects of hVEGF-DΔNΔC in endothelial cells using gene array, signaling, cell culture, and in vivo gene transfer techniques.
Methods and Results—Concomitant with the angiogenic and proliferative responses, hVEGF-DΔNΔC 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-DΔNΔC stimulation, whereas induction with hVEGF-A165 altered the expression of STC1 and NRP1, another coreceptor for VEGFs. The effects of hVEGF-DΔNΔC were seen only under high-serum conditions, whereas for hVEGF-A165, the strongest response was observed under low-serum conditions. The hVEGF-DΔNΔC-induced upregulation of STC1 and NRP2 was also evident in vivo in mouse skeletal muscle treated with hVEGF-DΔNΔC by adenoviral gene delivery. The importance of NRP2 in hVEGF-DΔNΔC signaling was further studied with NRP2 small interfering RNA and NRP antagonist, which were able to block hVEGF-DΔNΔC-induced survival of endothelial cells.
Conclusion—In this study, the importance of serum and upregulation of NRP2 and STC1 for VEGF-DΔNΔC effects were demonstrated. Better knowledge of VEGF-DΔNΔC signaling and regulation is valuable for the development of efficient and safe VEGF-DΔNΔC-based therapeutic applications for cardiovascular diseases.
- Received December 2, 2008.
- Accepted March 24, 2011.
- © 2011 American Heart Association, Inc.