|
Fig. 10 The effects of formononetin on angiogenic sprouting in the SIVs of Tg (fli1: EGFP)y1 and Tg (fli1: nEGFP)y7 zebrafish embryos.
(A,a) Tg (fli1: EGFP)y1 and Tg (fli1: nEGFP)y7 zebrafish embryos (48 hpf) were treated with 0.1% DMSO for 24 h to serve as negative control. The SIVs of zebrafish embryos at 72 hpf developed into a smooth basket-like structure. Zebrafish embryos (48 hpf) treated with formononetin for 24 h at (B,b) 25 µM or (C,c) 50 µM showed that there was an increase of sprouting in the subintestinal vessels (SIVs) baskets stretching into the posterior yolk extension. (D,d) Zebrafish embryos were injected with zebrafish VEGF-A (ZF-VEGF-A) (1 ng/embryo) at 1 hpf and incubated in embryo medium until 72 hpf to serve as positive control. Yellow arrows indicated sprouting vessel formation; white asterisks indicated intersection branch formation. Statistical analysis showed that formononetin increased (E) the length of vascular sprouting in the SIVs and (F) the number of endothelial cells in the SIVs in a dose-dependent manner. The number of endothelial cells was measured using Image J software package. Data are plotted as mean ± SD, (n > 3), *p < 0.05, **p < 0.01 vs. control.