Fig. 6.
Rg1 regulation of angiogenic activity requires HIF-1α. a HUVECs were transfected with 10 nM HIF-1α siRNA or nonspecific (NS) siRNA in the presence or absence of 150 nM Rg1 for 1 h. Total cell lysates (50 μg) were subjected to immunoblotting with antibodies against HIF-1α, VEGF, and β-actin. b Angiogenesis was assessed by tube formation 6 h after treatment. 1 × 105 cells/well were seeded in growth factor-reduced Matrigel-coated 24-well plate in medium 199 containing 1% fetal bovine serum. c Cells were pretreated with 10 μM LY294002 (LY) or 10 nM rapamycin (Rp) and then treated with or without 150 nM Rg1 for 6 h and assessed by angiogenic tube formation. Data are shown as mean ± SD of the number of tube-like structure relative to the control, which was set to be 100%, counted in 12 microscopic fields of three independent experiments. Bar 50 μm. *P < 0.05, difference with untreated control