Effect of nerve growth factor on angiogenesis of in vitro cultured murine aorta ring and key role of TrkA

AIM To explore the effect of nerve growth factor (NGF) on angiogenesis of in vitro cultured murine aorta ring. METHODS ①Murine aorta rings were cultured in 3D Matrigel in serum-free medium in the presence of various concentrations of NGF for different time periods. The identification of sprouted vascular endothelial cells was confirmed by immunofluorescent staining. The configuration of sprouting was observed and photographed under phase contrast microscope and the average sprouting area per high power field was measured by Image Pro software and analyzed statistically with SPSS13.0 software. ②NGF neutralizing antibody or vascular endothelial growth factor (VEGF) receptor 2 (R2) antagonist SU5416 pretreatment was used to investigate the effect of NGF or VEGF on angiogenesis. ③Tyrosine receptor kinase A (TrkA) antagonist K252a pretreatment was used to investigate whether NGF exerted its angiogenic effect through its receptor TrkA. RESULTS ①Exogenous NGF promoted endothelial cell sprouting from murine aorta rings cultured in Matrigel in dose-dependent manner. Sprouted cells expressed CD31. Anti-NGF neutralizing antibody markedly blocked NGF-induced sprouting angiogenesis. ②SU5416 significantly reduced VEGF-induced angiogenesis but had no significant effect on NGF-induced sprouting. ③K252a significantly inhibited NGF-induced angiogenesis. CONCLUSION NGF promotes angiogenesis of murine aorta ring through activating TrkA receptor, which may provide some new insights into pro-angiogenic therapy.